7 Serials ISSN 0038-3872 QH 1 S69 v.104 no. 1 24116-20 Seamer RN CALIFORNIA ACADEMY OF SCIENCES BULLE Volume 104 Number I Si ED mt ee r Barvat Lake Marron Valley ..cmeeoee 8" pee se, Lo 76 : le Creek BCAS-A104(1) 1—44 (2005) LIBRARY April 2005 Southern California Academy of Sciences Founded 6 November 1891, incorporated 17 May 1907 © Southern California Academy of Sciences, 2005 OFFICERS John Dorsey, President Brad Blood, Vice-President John Roberts, Secretary Daniel A. Guthrie, 7reasurer Daniel A. Guthrie, Editor Ralph G. Appy, Past President Robert Grove, Past President David G. Huckaby, Past President Daniel J. Pondella, Il, Past President BOARD OF DIRECTORS 2002—2005 2003—2006 2004—2007 Ralph G. Appy M. James Allen Brad Blood Jonathan N. Baskin John H. Dorsey Donald G. Buth John Roberts Judith Lemus Robert S. Grove Gloria J. Takahashi Karen Martin Kathy Keene James Landry Susan Yoder Edith Reed Membership is open to scholars in the fields of natural and social sciences, and to any person interested in the advancement of science. Dues for membership, changes of address, and requests for missing numbers lost in shipment should be addressed to: Southern California Academy of Sciences, the Natural History Museum of Los Angeles County, Exposition Park, Los Angeles, California 90007-4000. Professional Members: (2.2) ne a co Bw a a a Student Members). S50) oa eo SE ee I Memberships in other categories are available on request. Fellows: Elected by the Board of Directors for meritorious services. The Bulletin is published three times each year by the Academy. Manuscripts for publication should be sent to the appropriate editor as explained in “Instructions for Authors” on the inside back cover of each number. All other communications should be addressed to the Southern California Academy of Sciences in care of the Natural History Museum of Los Angeles County, Exposition Park, Los Angeles, California 90007-4000. Date of this issue | April 2005 This paper meets the requirements of ANSI/NISO Z39.48-1992 (Permanence of Paper). SOUTHERN CALIFORNIA ACADEMY OF SCIENCES CALL FOR PAPERS 2005 ANNUAL MEETING May 20-21, 2005 LOYOLA MARYMOUNT UNIVERSITY LOS ANGELES 4 Woor TED \99 O The Southern California Academy of Sciences will hold its 2005 annual meeting on the campus of the Loyola Marymount University, Los Angeles. Presently planned symposium topics are listed below. Additional proposed symposium topics are invited. Please contact John Dorsey ( jdorsey@Imu.edu) to propose additional symposia. Details of the meeting, announcements and general instructions for pre-registration, abstract preparation and submittal are given on the meeting web site at http://scas.jsd.claremont.edu/. Contributions may be in any area of science or mathematics. In recent years, papers have concentrated in the fields of marine and aquatic biology, terrestrial biology, ecology, systematics, population biology, biogeography and geology. Planned Symposia Friday, May 19, 2005 Wetland Ecology: work on coastal marshes and their pollution. Ecology of Nearshore Reefs: a continuing symposium on the ecology of rocky substrates. Archeology of Southern California: devoted to studies of California prehistory. Paleontology of Southern California: recent discoveries on the prehistory of our area. Planned Symposia, Saturday, May 20, 2005 Fire Ecology: Studies of recent wildfires in southern California. Avian Biology: Work on Southern California avifauna, especially endangered species. SETAC: The Society of Environmental Toxicology and Chemistry will hold Three sessions on New Frontiers in Environmental Chemistry, as follows: Tools for tracking the fate of wastewater derived contaminants in effluent dominated waters Contaminant fate and source tracking using chiral and stable isotopic signatures Chemical methods for measuring bioavailability Contributed papers: Sessions of Contributed Papers will occur both days. IN ADDITION, HIGH SCHOOL MEMBERS OF THE JUNIOR ACADEMY WILL PRESENT THEIR PAPERS ON SATURDAY. Plenary Speakers will be: Friday: Dr. Brian Fagan “*Fish on Friday: How Catholic Doctrine of Eating Fish on Friday Changed History” Saturday: Dr. James Powell: “‘Death of the Dinosaurs: Bad Genes or Bad Luck’?”’ Digitized by the Internet Archive in 2012 with funding from California Academy of Sciences Library http://archive.org/details/bulletin8/39sout Bull. Southern California Acad. Sci. 104(1), 2005, pp. 1-13 © Southern California Academy of Sciences, 2005 Biological Assessment of Tecate Creek (U.S.-—Mexico) with Special Regard to Self-Purification Volker Liideritz,! Frauke Gerlach,'! Robert Jiipner,'! Jesus Calleros,? Jerome Pitt,? and Richard M. Gersberg?* 'University of Applied Sciences Magdeburg, Department of Water Resources Management, Breitscheidstr. 2, D—39114 Magdeburg, Germany *San Diego State University, Graduate School of Public Health, 5500 Campanile Drive, San Diego, California 92182/4162, USA Abstract.—Macroinvertebrate organisms were sampled at four sites on Tecate Creek (U.S.—Mexico) and quantitatively evaluated using the SIGNAL-w (Stream Invertebrate Grade Number—Average Level-weighted) index. A morphological assessment of the stream structure was also carried out. Bioindication by SIGNAL reflected a very low water quality in the upper three sampled stream reaches, but with a significant improvement by the last site on the Rio Alamar, but only to a grade of critical to high pollution over a flowing distance of 29 km. Levels of BOD and ammonium-N at the Rio Alamar (Toll Bridge) site remained quite high, 56 mg/L and 48 mg/L, respectively. Metal levels also generally decreased as the water flowed downstream to the the Rio Alamar. Despite the fact that Tecate Creek has a quite natural morphological structure, solid inorganic surfaces and aquatic macrophytes (as settkement area) are mostly absent in Tecate Creek. This lack of stable habitats prevents the development of an effective biofilm which would significantly enhance self-purification. The Tijuana River Watershed (TRW) is a binational watershed on the U.S.— Mexico border, encompassing much of the cities of Tijuana and Tecate in Mexico and portions of the City and County of San Diego in the U.S. The basin contains three surface water reservoirs, various flood control works, and a National Estu- arine Sanctuary in the U.S. which is home to several endangered species. For decades, raw and poorly treated sewage from the cities of Tijuana and Tecate, Mexico has flowed into the Tijuana River and across the international border into the United States. Pollution in Mexico has been caused by rapid population growth and urbanization, poor land-use practices, and inadequate sewage treat- ment and collection facilities in the watershed (Ganster 1996). A fast growing aspect of industry near the border has been the “‘maquiladoras.’’ The term *“‘ma- quiladora’”’ refers to an industry established under a special customs allowance, mostly non-Mexican operations to establish manufacturing plants in Mexico that are allowd to import duty-free raw materials, equipment machinery, and replace- ment parts (Turner et al. 2003). The maquiladora industry, fueled primarily by foreign investment, has grown faster than the capability of the municipality to deliver services to them. Moreover, the lack of pollution prevention measures for industry and other businesses in Mexico, coupled with a deficiency in proper * Corresponding author: rgersber@ mail.sdsu.edu l WN SOUTHERN CALIFORNIA ACADEMY OF SCIENCES i f Barrat Lake Marron Valley... axes" * (Fe Of, Creag Big Pipe Toll Budge t io Alam® {0 Fig. 1. Map of sampling sites (denoted by open circles) on Tecate Creek and the Alamar River. Shaded (both light and dark) sections of stream segments represent reaches where ecomorphological assessment was made. The location of the discharge from the Tecate Municipal Wastewater Treatment is denoted as ““WTP”’. The location of the discharge from the Tecate Beer Brewery and the Tecate maquiladora complex are denoted by ““Brew” and ‘“‘Maq”’ respectively. Map adapted from the Tijuana River Watershed GIS database. 2000. enforcement of existing regulations, has generated pollution that contaminates the tributaries of the Tijuana River and ultimately the Pacific Ocean. The city of Tecate, Mexico is located in the eastern section of the Tijuana River watershed (Figure 1). In 2000, the population of Tecate was nearly 80,000 per- sons, with this number expected to increase to around 150,000 by the year 2020 (INEGI 2000). In urban Tecate, major point sources of pollution to Tecate Creek include the discharge of poorly treated sewage from the Tecate Municipal Plant, the discharge of high BOD-containing waters from the Tecate Brewery, and ef- fluent discharge from a maquiladora complex which includes a large metal-work- ing industry and the effluent from a slaughterhouse. Due to these discharges, flow in Tecate Creek occurs throughout the year, even during the summer dry season when the stream would naturally have little or no flow. Downstream, Tecate Creek joins Cottonwood Creek in the U.S. to form the Rio Alamar (Figure 1), which eventually joins the Rio de las Palmas in Mexico to form the Tijuana River. Due to the major point sources of pollution mentioned above, as well as typical urban non-point sources, Tecate Creek may account for a significant part of the loading of a variety of pollutants to the downstream Tijuana River watershed and the Tijuana River Estuarine Research Reserve in the U.S. (Englert et al. 1999; Gers- berg et al. 2000; Gersberg et al. 2002). The purpose of this study was to measure the degree of contamination in Tecate Creek, and the extent to which these contaminants, including heavy metals, or- ganic pollution (BOD and COD), nutrients (N and P), and fecal indicator bacteria, BIOLOGICAL ASSESSMENT OF TECATE CREEK (U.S.-MEXICO) 3 are reduced by self-purification downstream. An additional aim was to perform an integrated biological assessment of Tecate Creek to determine the effects of such pollution on the ecological development potential in this stream. Our overall ecomorphological investigations also allowed an examination of the potential of this stream for restoration efforts that could improve water quality in the Tijuana River watershed. Materials and Methods Chemical and Microbiological Assessment In January and February 2002, water samples were taken four times from five sites on Tecate Creek and the upper Rio Alamar. The sites were: WTP 2 (down- stream of the Tecate Municipal Wastewater Treatment Plant), Tecate, Marron Val- ley, Big Pipe, and Toll Bridge on the Rio Alamar (Figure |). Sampling was done at each site over a period of one hour, where each sample represented a composite sample of 6 grab samples taken every 10 minutes. Samples were analyzed for dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), the heavy metals cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn), the plant nutrients (nitrogen and phosphorus), and total and fecal coliform bacteria. At an additional site (designated WTP 1, upstream of Tecate Municipal Wastewater Treatment Plant) samples were only analyzed for metals. To be sure that our samples approximate the same parcel of water as it moved downstream, the ““flowing-wave’’-method (Heidenwag et al. 2001) was used. This method involved measuring average flow velocities (Global FP201 Flow Probe) at each of the sites, calculating the average time of flow downstream to each site, and timing the sampling at successive sites to correspond with the flow of water. Samples were analyzed according to the Standard Methods for the Examination of Water and Wastewater (APHA 1995). Chemical oxygen demand (COD) which reflects the level of organic carbon, was measured by the reactor digestion method. Biological oxygen demand (BOD) which reflects the level of assimilable organic carbon, was estimated by the 5-day BOD incubation test. The plant nutrients nitrogen and phosphorus were measured by colorimetric methods. Nitrate was analyzed by the cadmium reduction method. Ammonium was measured by the nesslerization method. Phosphorus was measured by the ascorbic acid method. Total coliforms and fecal coliforms were counted according to the most-probable- number method (MPN). For metals analysis, water samples were filtered using cellulose acetate membrane filters (0.45 jsm-pore-diameter). Filtrates were acidi- fied to pH 2 with concentrated nitric acid and used directly for Cd, Cr, Cu, Ni, and Pb dissolved metal analysis (APHA 1995). This analysis was performed using a Perkin-Elmer (SIMMA 6000) Graphite Furnace Atomic Absorption Spectrom- eter (AAS). Zn was analyzed by flame atomic absorption spectrometry using a Buck Scientific flame atomic absorption spectrophotometer (Model 210 VGP). For particulate metal analyses, filters were digested using concentrated nitric acid (APHA 1995). QA/QC included the use of reagent blanks, duplicate samples, recovery of standard concentration, and calibration of standards. Mean percent variation among the duplicates for all metals tested ranged from 2.3%—15.9%. Mean (n = 3) sample recoveries from a trace element calibration standard (2709 4 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES San Joaquin soil, National Institute of Standards and Technology) ranged from 94.4 to 101.0% for all of the metals tested. Self purification performance was calculated by dividing the pollutant concentration difference (mg/L) or bacterial density (MPN/IOO mL) difference at the first (upstream) and last sampling sites by the flowing distance (km) between them. Hydrobiological Evaluation Between October and December 1999, from July till September 2000, and from November 2001 to January 2002, macroinvertebrate organisms were sampled al- together three times in four 100 meter reaches (WTP 2, Tecate, Marron Valley (U.S.), Toll Bridge; see Figure |) always over a period of one hour. Thereby, all biotope structures (bottom substrate, aquatic plants) were sampled by means of a handnet with a mesh size of 0.5 mm. The organisms were fixed in ethanol (70%) and estimated according to Merrit and Cummins (1996). Biotic Index according to Chessman (1995) was calculated. This calculation is based on the fact that numerous families of macroinvertebrates that are widespread in river systems nearly all over the earth have been awarded sensitivity grades according to their tolerance or intolerance of common types of pollutants as summarized by Chess- man (1995). However, in some cases the grades are necessarily a compromise, either because of variation in the sensitivities of species within a family or because some families are sensitive to certain types of pollutants but relatively tolerant to others (Chessman 1995). The index SIGNAL-w (Stream Invertebrate Grade Num- ber—Average Level, weighted by the occurrence) was calculated by multiplicat- ing the grade of each family present by the value to represent its occurrence level (e.g. | for only | individual, 7 for mass development), summing the products, and dividing by the sum of the occurrence values. Ecomorphological Assessment Using the methods of ecomorphological mapping according to Liideritz et al. (1996) and Heidenwag et al. (2001), the 29 km of the streamcourse of Tecate Creek (and the upper section of the Rio Alamar) were mapped and evaluated in 9 reaches shown in Figure 1. The following main parameters were registered: — stream course development — lengthwise profile — crosswise profile — bottom structure — bank structure — structure of surroundings These 6 main parameters are joined by 27 single parameters; an overview is given im Table. The quality of ecomorphology is evaluated by 7 classes of structure grade: Grade |: not disturbed, natural morphology Grade 2: slightly disturbed, unimportant changes which do not influence func- tionability of the waterbody Grade 3: moderately disturbed, changes of morphology are obvious and disturb the ecology of the waterbody to a measureable degree ‘(7 omnst4) deur uo uMOYS se 6—-] D1OY poyeusisap pue poydures sayoros wieRsays , uOeNIvAD [PUI N N = N — N ISLIDAY SOINIONS ISIOAPY SOUOZ UOT}ID9}OIg osn voly sSuIpUuNnOLINS _— NATO QI Sic GEN EA CO) QE EAN GQ NAAN NANN ss Gay Ney Sar G9) NANYM AN — eA Ne) ISLIDAV soinjonys yurq jeinjeu yeroads sulAed yueg uOTeIAaSIA Yue soon yueg ainjonys yueg GARG SSCA GN Se ON = QS aN QQ Scar a =a Ne eo NaAaAA Yo ISVIOAV AVISIOAIP ayeSqnS sainjon.ys wWioyog [eInjeu [e1oads soinjon.ys UO0T}99}01d UWO}WOQ IDATY ajeysqns woyog ainjonys Woo, Tt 169) GN Seat GN CONG EGNIEGNESIGNEG Tod GNESI COS SGN ASS QIAN NANMON WA 116m! Se CO lag) foe) = ISLIDAYV SLOAN AJOLIeA UIPIAA uOISOIa yUueg ajyoid Jo yidaq ajyoid jo addy, a]yoid asimssolg GNI GN SGNECA GN ase entAN Se ANNAN AN SS SS SS = SS SS SS SS — ee (a) fan) (a) (ca) [B= Spe Nel I Gn) Val Gal GNI Ge@iiiss! (et! (es) NANM AN Mra TA oa) ISCIDAV uonenea yidoq AVISIOAIp JUdIIND syurq ISIMSSOID suldig Joyemyorg SUOTIONIJSUOD ISIMSSOID a]yoid asimyjsuay =a No ie! NEN CRASH "AVeN AA ASC) CNT Ga Val Sl Od Wal Sar Gol Galt ss CO” Aap Sep Ne) Wal G9) ae NAN Ss see N SNe ae eNAN aan ae anNN ae el io aa eNAS ase ananan =e amM “ ISvVIDAV somnjonys asinoo jersads syueqg osIMysUuaT] UOISOIOD SUIPUdg SUIpUdg ISINO_D jusuIdoJaANp IsINOD WRANS *| MAATTAN AAW AN MAA TAN NANANTAN Naa Nac co QCA QT GQ MOMATAWN Ga NGC Siu COGIC) ISLIDAY I sous surddew jyuasajjip ye siojowresed jenprarpuy Jajouered ureyy oy 00 é~ No) va) t (oa) N BIOLOGICAL ASSESSMENT OF TECATE CREEK (U.S.-MEXICO) IOATY IVUILYW/YOdID aWedsap, JO ,;SOyORdI WUIRdI]S Poyoajas Je JUDUISSaSSY [BOIsOT;OYdIOUIODY FO syNsoy “[ WqQeL 6 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES Table 2. Land use characterization of Tecate Creek/Alamar River sub-basin drainage area down- stream of urban Tecate, Mexico.! Description Hectares Percent area Commercial 36.70 0.31 Dispersed residential oan 0.80 Disturbed/under construction 358.48 3.01 Extractive industry 51.74 0.43 Improved pasture 55.90 0.47 Industrial DIESS 0.44 Institutional 13.46 0.11 Non-developed lOM97 70 85.58 Open grazeable land 536.20 4.50 Recreation 130.60 1.10 Residential 113.44 O95 Row crops S133 O77 Transportation 142.85 1220 Tree crops 34.72 O28 Water body 4.65 0.04 Total Area in Acres Ses) 100.00 ' Tijuana River Watershed GIS database 2000. Grade 4: clearly disturbed, waterbody shows a clear distance from natural status, is straightened and lined to a degree up to 50% Grade 5: markedly disturbed, straightening and lining reach a percentage of 100 Grade 6: heavily disturbed, natural dynamics are avoided by bank pavement and lining Grade 7: excessively disturbed, channelization 1s complete Morphological assessment was done by comparing undisturbed stream reaches upstreams of Tecate (reference reaches) with the mapped sites. Results Tecate Creek has quite natural morphological structures, almost without typical problems like lining, straightening, and bank paving (Table 1). Expressed as a meander valley river and braided system, it shows a flat type of profile with a natural course with meanders and lengthwise banks, as well as a relatively high current diversity and depth variation. It generally has natural bank vegetation consisting of loose trees and shrubs. There are no dams or backwaters (and few culverts) on Tecate Creek. Downstream of Tecate, there are no adverse structures or any intensive landuses (Table 2). Indeed, downstream of urban Tecate, 90% of the land area that drains into Tecate Creek or the upper Alamar River, is either undeveloped or open grazable land, with industrial, commercial, and residential land uses (combined) only comprising less than 2% of the area (Table 2) (Tijuana River Watershed GIS database 2000). This data supports our visual observation that there are no major pollutant sources downstream of urban Tecate that would confound our analysis of self-purification efficiencies. On the other hand, the substrate of Tecate Creek is very uniform (gravel par- tially filled with sewage sludges) and the river is oversaturated with these sedi- ments (braided system). Solid surfaces are very rare, and biofilms that play an BIOLOGICAL ASSESSMENT OF TECATE CREEK (U.S.-MEXICO) q Table 3. Settlement of representative sites on Tecate Creek/Alamar River with macroinvertebrates used for SIGNAL-w calculation. Sensitivity Occur- Sample site Family (genus species) grade rence SIGNAL-w WTP2 Psychodidae (Psychoda sp.) 2 4 15 Culicidae 2 2. we Chironomidae | D oxeessively Tubificidae (Tubifex tubifex) ] 4 polluted) Tecate Psychodidae (Psychoda sp.) D) 2 Chironomidae (Chironomus spp.) I l 17 Stratiomyidae 2 | (excessively Ceratopogonidae 6 | polluted) Tubificidae (Tubifex tubifex) | qd Marron Valley Psychodidae (Psychoda sp.) 2 2 Chironomidae (Chironomus spp.) ] 3 | Ceratopogonidae 6 l os (heavily Tabanidae 5 | Coenagrionidae (Agria sp.) 7] | perce Tubificidae (Tubifex tubifex) | w) Toll Bridge Psychodidae (Psychoda sp.) D, 2 Chironomidae (Chironomus spp.) | 2 Tabanidae (Chrysops sp.) 5 | Simulidae (Simulium venustum) ») ] 3.1 Coenagrionidae (Ischnura sp. Argia sp.) g| 2 (critically Aeshnidae (Anax sp.) 6 | polluted) Belostomatidae (Belostoma sp.) 5 | Dytiscidae (Rhantus sp.) =) | Gammaridae 6 | Tubificidae | 7 outstanding role in self-purification can develop only poorly due to this fact, and because of the friction between sediment particles which leads to a lack of stable habitats. Microscopic observation showed that very thin biofilms formed by fil- amentous bacteria and algae only existed on about 10% of the gravel surface. Bioindication by SIGNAL-w reflects a very low water quality with index values of:1.5 to 2.1 in the upper three sampled stream reaches at WTP 2, Tecate, Marron Valley (Table 3). By the last site (Toll Bridge) on the Rio Alamar, there was significant improvement, but even here the index value of 3.1 represented a system still critically polluted (Table 3). Macroinvertebrate settlement at all sites is dom- inated by those Diptera larvae and Tubificidae which do not demand a high water quality; their high abundances indicate a polysaprobic status (i.e. a very high organic load). Sampling for this study was all conducted under dry weather (baseflow) con- ditions when Tecate Creek was polluted to a very high degree with organic sub- stances, plant nutrients, heavy metals, and fecal indicator bacteria (Table 4, Fig- ures 2—7). With regard to self-purification, we found only a poor performance concerning organic substances and nutrients. Over a distance of 29 km (from site WTP 2 to the Toll Bridge on the Rio Alamar), BOD decreased only by 53% (2.14 mg/L km), COD by 84% (14.31 mg/L km), ammonium by only 4% (0.07 mg/L km), and total P by 51% (0.32 mg/L km). However, even this modest reduction SOUTHERN CALIFORNIA ACADEMY OF SCIENCES Oe a EE EE a asa: ann eee CC + LBI LI + I8l cy + LIC 8c + ILI le + 16] PIs = (S/D) MOTH €+9 9¢ + O81 Ocl + SIC 9c + OS9 Scr + OOOT PIS = OOOI & (TH OOT/NdW) SWIIOJI[OD [BI94 CVc + SOL TIT + OS6 SOS + OOIT OOST + O06C 6061 + OS9E PIS = OOO! * (TH OOT/NdW) SUIOFJITOS [BIOL Ol +28 LO + 16 Glee Vv Ol $C OST OE + OLI pis = (7/su) dL VC + © 8V 87+ 8 Es Cc + 08S CO + ESS ce + € OS pis = (7/sw) N-+?7HN L + 6 p+ 69 Oy Se IL Cl = oC i= Siz PIS + (%) uoTeINes-Od SCRE LL CC = GEL 6c + LLI C+ OLE 89 + COV PIs = (FT/S) dOD L+ 9S 8. == Le Ol + LV Cl + El Cl = Sil pis = (7/sw) dod osplg [[OL adig sig Ag[eA UOLeIy 91899], ZT dLM sug Jo\ouIe Ie NS eee nnn ‘sous Surjdures ¢ yw painsvoul sv UY 67 JO SOURISIP B JOAO JOATY JEWRY PPI aVIAL_ JO uoneoytind-jjag “Pp 21qeL BIOLOGICAL ASSESSMENT OF TECATE CREEK (U.S.-MEXICO) 9 a fe Dissolved Cd 120 5 —a— Particulate Cd a —O-— Dissolved Cu SB 100 — —a— Particulate Cu =a 80 | —~9~ Dissolved Pb c —@— Particulate Pb o [eC = 60 5 ; r= oO 40 7 Co) c Oo 205 oO = = —4 WTP1 (n=5) WTP2(n=4) ~~ Tec (n=10) MV(n=5) Big Pipe (n=7) Toll Bridge (n=8) Site Fig. 2. Levels of dissolved and particulate cadmium (Cd), copper (Cu) and lead (Pb) in Tecate Creek/Alamar River; n denotes the number of samples taken at each site. Levels of disolved Cd are so low (<0.15 pg/L) that they do not show in the this figure. of the organic and nutrient loads could be responsible for the appearance of some higher-demanding macroinvertebrate organisms especially at the last site on the Rio Alamar (Table 3). Nitrification seems to be nearly totally absent, probably because of the high organic carbon levels in the water which leads to the dominance of heterotrophic bacteria and suppresses the development of nitrifying organisms (Table 4). Mean- while, the decrease of total coliform densities remains moderate, with an 87% (110 X 10° MPN/100 mL km) removal efficiency; while fecal coliforms are re- duced (69 X 10? MPN/100 mL km) with a rather high efficiency of 99.7%. For most metals, there was a significant loss of the particulate (as well as the dissolved) fraction, as the water moved downstream in Tecate Creek to the Rio Alamar (Figures 2—3). Surprisingly, for Cu, Cr, and Ni, the highest levels observed among all of the sampled sites was actually at WTPI (this site upstream of the discharge point for the Tecate Municipal Wastewater Treatment Plant), where levels of these metals were 98, 345, and 518 wg/L, respectively. It should be 350 5 '|_~- Dissolved Cr | | Es Particulate Cr | 50 m) at the southern entrance to Bahia de Los Angeles. These large adults (210—295 mm SL) readily took bare hooks and seemed to be exhibiting an aggregational behavior similar to that observed in Southern California waters (Larry Allen, CSU Northridge, personal communication). Spotted sand bass from Bahia de Los Angeles did not differ in growth from AGE AND GROWTH OF SPOTTED SAND BASS IN BAHIA DE LOS ANGELES 21 Percent opaque 100 90 80 70 60 50 40 30 20 10 Spring Summer Fall Winter Fig. 5. Frequency histogram of edge type determined from transverse otolith cross sections. A total of 499 otoliths were used in the edge analysis (Spring n = 161, Summer n = 74, Fall n = 198, Winter n = 66). The percentage of opaque edge type is given on top of the bars for each respective season. log (standard length) O COV O Gulf of California x Pacific Coast — —Linear (Gulf of California) Gulf length = 0.153x + 4.75 (r° = 0.682) Pacific coast length = 0.0182x + 2.30 (r° = 0.493) || —— Linear (Pacific Coast) 0 2 4 6 8 10 1 14 16 Age (years) Fig. 6. Plot of log-linearized standard length and age for the Pacific coast population (Allen et al. 1995) and the Bahia de Los Angeles population with the corresponding regressions used to calculate growth trajectories. i) i) SOUTHERN CALIFORNIA ACADEMY OF SCIENCES fish collected further north in the Gulf, but this finding must be qualified by the low samples size and limited size range of these collections. To further check for differences we added the aged fish to the VBGF data from Bahia de Los Angeles to see if it changed the parameters to any extent that could be considered signif- icant. The criteria used was the 95% confidence interval for the VBGF parameters. The growth coefficient (k) decreased slightly to 0.256 = 7.7% and the asymptotic length (L..) increased slightly to 314 + 2.9% mm SL. Neither changed signifi- cantly in this rather subjective test and we concluded that growth in the northern Gulf is probably similar throughout the region. The growth trajectory of spotted sand bass in Bahia de Los Angeles differs from that of the Pacific coast populations as well as its congeners. Specifically, spotted sand bass in the northern Gulf grow faster than those found in Pacific coast populations, contrasting greatly in terms of the growth coefficient (>0.25 vs 0.1077; Allen et al. 1995). This is also much higher than that of its longer- lived congeners, kelp bass (P. clathratus, k = 0.06; Love et al. 1996), barred sand bass (P. nebulifer, k = 0.08; Love et al. 1996), and golden spotted rock bass (P. auroguttatus, k = 0.115; Pondella et al. 2001). In addition, this growth rate is more typical of tropical serranids and resides among the faster growing fishes (e.g. Manooch 1987). In this study, some one year old fish had reached nearly 200 mm SL and some had exceeded this length by their second year. The rela- tively high growth rate described in this study is driven by the small fish collected from Bahia de Los Angeles coupled with growth to large size within the first few years, and its relatively short longevity (11—12 yr). It is possible that larger, and presumably older, fish were missed in Bahia de Los Angeles despite our collection efforts. A maximum length of 559 mm total length (TL; ca. 500 mm SL) is given for spotted sand bass (Thomson et al. 1979). This is much larger, however, than any specimen reported here or by Allen et al. (1995). A follow up communication about the source of the high maximum length revealed that there was no support for the claim (Lloyd Findley, CIAD-Unidad Guaymas, personal communication). As a result, the maximum length of spotted sand bass in the Gulf of California was reduced to a substantiated 381 mm TL (ca. 336 mm SL) in the revised edition of Reef Fishes of the Sea of Cortez (Thomson et al. 2000). The length-weight relationship, when considered with respective ages, is useful in describing the variability of growth for this species. Spotted sand bass can become large fish in a relatively short period of time, while smaller fish can be considerably older than the largest fish. In this study, the oldest fish was a low weight individual with a length close to the longest fish (525 g at 308 mm SL). This fish seems atypical of the Bahia de Los Angeles population. The largest fish, those with the greatest weights and lengths, had low to average ages (3-7 yr). The largest individual in this study weighed only half as much as the largest spotted sand bass taken in the southern California population (>1800 g at 400 mm SL; Allen et al. 1995). While the differences in size and age between the Pacific population and the Gulf population can be explained by the disjunct dis- tribution of the species (Trahan and Allen 1999), the plasticity of size and age within the population is a bit of a mystery. It may be explained by localized habitat variability, timing of oceanic events, or competition to broadly qualify a few factors. The oldest fish not being the largest or heaviest fish, however, is AGE AND GROWTH OF SPOTTED SAND BASS IN BAHIA DE LOS ANGELES 28 becoming a relatively common observation in fishes (e.g. rockfishes, Cailliet et al. 2001). Despite the limited temporal resolution of a seasonal application of the edge analysis, the results indicate the annual interpretation of growth zones in otolith sections is valid for spotted sand bass in Bahia de Los Angeles. Sampling once per month over a period of one year would have been optimal (Campana 2001), but the remote nature of Bahia de Los Angeles precluded this kind of sampling design. Based on the seasonal sampling, it is clear that an opaque growth zone is formed once a year over the summer months with a low probability of the opaque zones forming in any other season. The other northern Gulf collections made at a time that corresponds with our Spring collections had a low incidence of opaque zone formation (13%); it 1s interesting to note that the Gonzaga Bay collections had the highest incidence of early opaque zone formation (24%, n = 46). In addition, the timing of opaque zone formation is in agreement with the findings for the Pacific coast populations (Allen et al. 1995). Spotted sand bass in the Bahia de Los Angeles region are fast growing fish that can attain an age of about 11 yr, a length of about 320 mm SL, and a weight of at least 820 g. In Bahia de Los Angeles they grow faster than fish in the southern California population, but attain a smaller maximum size and a younger maximum age (Allen et al. 1995). The average annual water temperature of Bahia de Los Angeles is higher and has a much greater range than is recorded for the southern California environment (Tranah and Allen 1999). Specific to the Bahia de Los Angeles region, a strong seasonal upwelling is induced by high wind and current speeds in the Canal de Ballenas, just outside the bay, coupled with the rugged island bathymetry. As a result of the upwelling conditions, Bahia de Los Angeles is one of the most productive regions in the Gulf of California (Thomson et al. 2000, Case et al. 2002). It is likely that temperature differences, coupled with the high seasonal productivity, explain the observed growth trajectory dif- ferences between the two populations. Acknowledgements We would like to thank most sincerely Dr. Jose Mercadé and the Glendale Community College Baja Field Studies Program for providing a field station and in helping with organizing field collecting logistics. Thanks to Larry Allen, Tim Hovey and some of his students (CSU, Northridge) for the ancillary northern Gulf fish ageing data used in this study. Special thanks to Carolina Espinoza at the Museo de Bahia in Bahia de Los Angeles for help with regional information and field trip planning. Many thanks to Cheryl Baduini, Tanya Bennett, Erica Burton, Karen Crowe, Lara Ferry-Graham, Korie Johnson, Lisa Kerr, Debbie Nebinzahl, Linda Snook, Richard San Fillipo, and Jodi Thomas for helping with collecting and processing fish, and for making these research trips successful and so much fun. Special thanks to Shirley Andrews and Carolina Espinoza for feeding hungry researchers. Thanks to Mike Foster and John O’Sullivan for support through use of boats and other necessary field equipment. Thanks also to Erica Burton, Larry Allen, and an anonymous reviewer for assistance in improving the manuscript. Thanks to the Dr. Earl H. Myers and Ethel M. Myers Oceanographic and Marine Biology Trust and the Padi Foundation for financial grants to support the return trips to the region for seasonal sampling. Thanks to California State University, 24 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES Fresno for use of a 4X4 truck and their understanding when it was returned in worse shape than when it left the parking lot. Finally, we express sincere appre- ciation to the late former Director of Moss Landing Marine Laboratories, Dr. John H. Martin, for providing the funding, equipment and supplies for the Advanced Topics in Ichthyology class project excursion to Bahia de Los Angeles in 1992; it was this trip that started the age and growth endeavor. Literature Cited Allen, L.G. 1985. A habitat analysis of the nearshore marine fishes from Southern California. Bull. Southern California Acad. Sci., 84(3):135—155. Allen, L.G., TE. Hovey, M.S. Love, and J.T. Smith. 1995. The life history of the spotted sand bass (Paralabrax maculatofasciatus) within the Southern California Bight. CalCOFI Report, 36:193— 203. Bocanegra-Castillo, N., L.A. Abitia-Cardenas, V.H. Cruz-Escalona, EK Galvan-Magana, and L. Campos- Davila. 2002. Food habits of the spotted sand bass Paralabrax maculatofasciatus (Steindachner, 1868) from Laguna Ojo de Libre, B.C.S., Mexico. Bull. Southern California Acad. Sci., 101(1): 13-23. Butler, J.L., G. Moser, G.S. Hageman, and L.E. Nordgren. 1982. Developmental stages of three Cal- ifornia sea basses (Paralabrax, Pisces, Serranidae). CalCOFI Report, 23:252—268. Case, T.J., M.L. Cody, and E. Ezcurra. 2002. A new island biogeography of the Sea of Cortes. Oxford University Press, New York, New York. 669 pp. Cailliet, G.M., A.H. Andrews, E.J. Burton, D.L. Watters, D.E. Kline, and L.A. Ferry-Graham. 2001. Age determination and validation studies of marine fishes: do deep-dwellers live longer? Exp. Gerontology. 36: 739-764. Campana, S.E. 2001. Accuracy, precision and quality control in age determination, including a review of the use and abuse of age validation methods. J. Fish Biology, 59:197—242. Chang, W.Y.B. 1982. A statistical method of evaluating the reproducibility of age determination. Can. J. Fish. Aquat. Sci., 48:734—750. Ferry, L.A., S.L. Clark, and G.M. Cailliet. 1997. Food habits of spotted sand bass (Paralabrax ma- culatofasciatus, Serranidae) from Bahia de Los Angeles, Baja California. Bull. Southern Cali- fornia Acad. Sci., 96(1):1—21. Hastings, P.A. 1989. Protogynous hermaphroditism in Paralabrax maculatofasciatus (Pisces: Serran- idae). Copeia, 1989(1):184—188. Hovey, TE., and L.G. Allen. 2000. Reproductive patterns of six populations of the spotted sand bass, Paralabrax maculatofasciatus, from southern and Baja California. Copeia, 2000(2):459—468. Love, M.S., A. Brooks, D. Busatto, J. Stephens, and P.A. Gregory. 1996. Aspects of the life histories of the kelp bass, Paralabrax clathratus, and barred sand bass, P. nebulifer, from the southern California Bight. Fish. Bull., 94:472—481. Manooch III, C.S. 1987. Age and growth of snappers and groupers. Pp. 329—373 in: Tropical snappers and groupers: biology and fisheries management. (J.J. Polovina and S. Ralston, eds.). Ocean Resources and Marine Policy Series. Westview Press Inc. Boulder, Colorado, 80301. Miller, D.J., and R.N. Lea. 1972. Guide to the coastal marine fishes of California. California Depart- ment of Fish and Game. Fish Bulletin 157. 249 pp. Oda, D.L., R.J. Lavenburg, and J.M. Rounds. 1983. Reproductive biology of three California species of Paralabrax (Pisces: Serranidae). CalCOFI Report, 34:122—132. Pondella II, D.J., J.A. Rosales Casian, and T-E. Hovey. 2001. Demographic parameters of golden spotted rock bass Paralabrax auroguttatus from the northern Gulf of California. Trans. Amer. Fish. Soc., 130:686—691. Stepien, C.A., R.H. Rosenblatt, and B.A. Bargmeyer. 2001. Phylogeography of the spotted sand bass, Paralabrax maculatofasciatus: divergence of Gulf of California and Pacific coast populations. Evolution; 55(9):1852—1862. Tranah, G.J., and L.G. Allen. 1999. Morphologic and genetic variation among six populations of the spotted sand bass, Paralabrax maculatofasciatus, from Southern California to the upper Sea of Cortez. Bull. Southern California Acad. Sci. 98(3): 103-118. N N AGE AND GROWTH OF SPOTTED SAND BASS IN BAHIA DE LOS ANGELES Thomson, D.A., L.T. Findley, and A.N. Kerstitch. 1979. Reef fishes of the Sea of Cortez: the rocky- shore fishes of the Gulf of California. John Wiley and Sons, New York. 302 pp. Thomson, D.A., L.T. Findley, and A.N. Kerstitch. 2000. Reef fishes of the Sea of Cortez: the rocky- shore fishes of the Gulf of California. University of Texas Press. 374 pp. Accepted for publication 16 September 2004. Bull. Southern California Acad. Sct. 104(1), 2005, pp. 26-36 © Southern California Academy of Sciences, 2005 Feeding Ecology of Salton Sea Tilapia (Oreochromis spp.) Ralf Riedel! Gulf Coast Geospatial Center College of Marine Sciences University of Southern Mississippi Ocean Springs, Mississippi 39564 Barry A. Costa-Pierce Rhode Island Sea Grant College Program, Department of Fisheries, Animal and Veterinary Science, University of Rhode Island, Narragansett Bay Campus, Narragansett, Rhode Island 02882-1197 Abstract.—We investigated the feeding ecology of tilapia (Oreochromis spp) in the Salton Sea. Stomachs and intestines were sampled at each season. Fish foraged at the surface during the summer when dissolved oxygen was low. The proportion of plant materials in fish stomachs was higher at river mouth areas. Diatoms dominated the phytoplankton; rotifers were dominant during the spring and sum- mer; copepods were dominant during the fall; barnacle larvae dominant during the winter. Pile worms (Neanthes succinea) were present throughout the year. Feeding activity was reduced in the summer, when dissolved oxygen was low and water temperature high. Intra-specific feeding plasticity 1s widely recognized in fishes (Wooton 1998) and is a function of environmental factors (Fryer and Iles 1969). Feeding strate- gies of cichlids are diverse and highly adapted to exploit a variety of niches (Fryer and Iles 1972; Maitipe and De Silva, 1985; Bowen and Allanson 1982). Tilapia are the most widely distributed exotic fish worldwide (Lowe-McConnell 1975; Bowen and Allanson 1982) because of their importance in aquaculture (Costa- Pierce and Rakocy 1997, 2000). The success of tilapia invasions is in part due to their ability to respond quickly to environmental changes by varying life history traits (Bruton and Allanson 1974; Noakes and Balon 1982) and exploiting mul- tiple trophic levels (Fryer and Hes, 1969; Bowen, 1982). Feeding patterns in the Mozambique tilapia (O. mossambicus) may be a func- tion of ontogeny and environment (Bowen and Allanson 1982). Mozambique tilapia in Lake Sibaya, South Africa, are known to be detritivorous and inhabit shallow areas in the juvenile phase and deep areas during adulthood (Brutton and Boltt 1975; Bowen 1979). Juvenile tilapia select the inshore areas in Lake Sibaya to seek refuge from predators (Bowen and Allanson 1982) and to take advantage of the more nutritious detrital aggregate (Bowen 1979). The Mozambique tilapia also has the ability to feed on plants and algae (Maitipe and De Silva 1985; Bowen 1982; DeSilva et al. 1984; Khallaf and Alme-na-ei 1987; Beveridge and Mc- Andrew 2000). Mozambique tilapia can digest cellulose in addition to microbial and particulate matter in sediments due to high stomach acidity, which may reach ' Corresponding author: ralf.riedel @usm.edu 26 FEEDING ECOLOGY OF TILAPIA Di a pH of less than 1 (Dempster et al. 1995). Tilapia have also been known to feed selectively on animal matter (De Silva et al. 1984). The Salton Sea is a 980 km7?, closed basin salt lake in the Sonoran Desert of southeastern California. The high salinity (44 g/L) and frequent wind-driven sum- mer deoxygenation events of the lake make it an extreme environment conducive to unique behavioral adaptations in fish. Over 70 species of marine fish have been introduced starting in 1929 (Walker et al. 1961) and over 30 species have been introduced in major numbers (more than 50 fish). Major introductions were done between 1950 and 1956 into the Salton Sea from Mexico’s Gulf of California (Walker et al. 1961) from which the orangemouth corvina (Cynoscion xanthulus, Jordan and Gilbert), Gulf croaker (Bairdiella icistia, Jordan and Gilbert) and sargo (Anisotremus davidsoni, Steindachner) established and flourished. During the late 1960s a hybrid tilapia (Oreochromis mossambicus Linnaeus * QO. urolepis hor- norum Linnaeus) invaded the lake (Costa-Pierce and Doyle, 1997) and became the dominant species (Costa-Pierce and Riedel 2000; Riedel et al. 2002). Because the Salton Sea tilapia have higher growth rates than conspecifics in other systems (Riedel et a/. 2002), nutritional constraints may not exist. Riedel et al. (2002) show evidence that the Salton Sea is a productive lake for tilapia, despite high summer water temperatures (over 32°C), frequent wind-driven anoxia over large areas, and high salinities. We investigated the feeding of Salton Sea tilapia to determine the possible reason for the high tilapia growth rates and production in the Salton Sea and to describe tilapia feeding ecology in this stress- ful environment. Methods Tilapia feeding was investigated by measuring stomach acidity, verifying the color of intestinal material, and determining stomach contents and fullness. Plank- ton samples were taken at the Salton Sea during the summer, spring, and winter to provide an estimate of food availability for tilapia. One hundred and fifty two fish were collected in the spring (43 fish), summer (38 fish), fall (38 fish), and winter (33 fish) from five stations at river mouth, nearshore, and pelagic areas (Figure 1) to assess feeding patterns according to seasons and sampling areas. Fish collections were done with multipanel, multimesh gill nets and plankton collections with a 40 1m mesh net. Stomach acidity was measured at all seasons with an Orion micro-combination pH glass electrode model 9802BN. The acidity from the upper, mid, and lower sections of the stomach was measured within | h of capture from five randomly selected fish at all stations. After the measurements, all stomach contents were transferred to glass vials containing 10% buffered formalin and given a unique identification code. Stomach contents and plankton samples were filtered out of the formalin solution in laboratory using a 40 jm mesh and transferred to 75% ethanol. Stomach fullness was estimated from the difference between the weight of the full and empty stomach. At one station only (Figure 1), one gillnet was set for one hour at dawn, mid-morning, mid-afternoon, dusk, and night to inves- tigate diel cycles in feeding, using stomach acidity as a proxy. The color of the intestinal contents was determined within 3 h of capture to estimate the degree of food assimilation of ingested material (Moriarty 1973). Intestinal material was identified as either green, indicating poor assimilation, or 28 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES ) pv. j/12m Alamo River ae L lowe ra — Fig. |. Sampling sites at the Salton Sea. R—river mouth; N—nearshore; P—pelagic. Arrow in- dicates station where data were collected for assessing diel patterns in tilapia stomach acidity. brown, for well assimilated food. No identification of organisms from intestines was attempted because of the advanced stage of digestion. Stomach contents were grouped into sediment, plant material (macrophytes only), and Salton Sea biota. Sediment comprised sand, clay, and microbial or- ganisms (not identified) and was used as a surrogate for determining foraging location within the water column. Macrophytes drift into the Salton Sea from land via the incoming tributaries. Marcophytes were considered because they are a potentially important tilapia food source, especially in the river mouth area. Salton Sea taxa were grouped further into benthos, zooplankton, and phytoplankton. Zooplankton were barnacles (planktonic stages of Balanus amphitrite), copepods (mostly Cyclopods spp), and rotifers (mostly Brachionus spp). Nematodes (mostly Spilophorella spp), ciliates, and pile worms (Neanthes succinea) were the benthic group. Phytoplankton consisted of dinoflagelates and diatoms. Groups of organ- isms Other than the above were observed, but not analyzed due to low (< 1%) frequency of occurrence. Percentages based on numbers of organisms within taxa were defined for analyses within those groups for each stomach. Analyses of seasonal and spatial variation in feeding were done independently for all groups. Percentages within taxa were averaged over individual fish to show taxa relative abundances according to space and season. Percentages, therefore, did not nec- essarily add to 100%. As a hypothetical example, if one fish had 100% of diatoms and another an empty stomach, the stomach content proportion was 50% diatoms for both fish taken together. The same rationale applies to proportions within groups. Because we report proportions of numbers, the often large abundance of phytoplankton would overwhelm all other taxa if no grouping was defined, over- estimating the importance of abundant taxa and possibly precluding analyses for other groups of organisms. FEEDING ECOLOGY OF TILAPIA 29 Spring [1 Summer Fall (0 Winter 40% Fig. 2. Mean percentages of ingested sediment over all stations by season present in tilapia stom- achs sampled at the Salton Sea. Spring n = 43, summer n = 38, fall n = 38, winter n = 33. Mean values were calculated from individual stomachs. Because of heteroskedasticity in the data, proportions were analyzed using dis- tribution-free statistical methods. Sediment and Salton Sea biota groups were an- alyzed for seasonal and spatial patterns. Kruskal-Wallis tests (Sheskin 2000) were used to assess seasonal and spatial patterns in feeding. Macrophytes were analyzed for spatial patterns only. The average percent of zooplankton in tilapia stomachs was compared with the percentages of taxa in plankton tows using a chi-square goodness-of-fit test (Sokal and Rohlf 1995) to estimate feeding electivity. Only barnacles, copepods, and rotifers were used because of the low occurrences of other taxa. Percent occurrence from plankton tows were the estimate for the ex- pected value and the percentages from tilapia stomachs were the estimate for the observed value when conducting the chi-square test. Feeding activity was estimated from the average acidity of the upper, mid, and lower section of each stomach (Moriarty 1973). A one-way analysis of variance (ANOVA) with color of intestinal material as the factor was used to assess the effect of stomach acidity on food assimilation. Diel and seasonal feeding activity was examined with a split-plot ANOVA (Winer ef a/. 1991), with time of day as the within factor and season as the between factor. Results The sediment proportion in stomachs was lowest during the summer (Figure 2; Kruskal-Wallis test statistic = 40.6, p < 0.01, 3 df). Macrophyte proportions were highest in river mouth areas (Figure 3; Kruskal-Wallis test statistic = 8.5, p = 0.01, 2 df). Diatoms were the dominant phytoplankton in the stomachs at all seasons and sampling areas. Diatom abundance was highest in the winter and spring and dinoflagellates highest in the spring (Table 1; Kruskal-Wallis test sta- tistic = 14.3, p < 0.01, 3 df). Neither dinoflagellates nor diatoms varied in abun- dance according to sampling area. The proportions of rotifers, copepods, and barnacles in stomachs varied with season (Figure 4; Kruskal-Wallis test statistic = 45.3 (barnacles), 74.0 (copepods), and 73.4 (rotifers), p < 0.01, 3 df). Rotifers were most common in the spring, copepods in the summer, and barnacles in the winter (Figure 4; Table 1). There was no evidence of a spatial pattern for either group. Chi-square tests indicated that there was no difference between the expected plankton percentages (plankton 30 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES 5% LJ Pelagic 0 11% { Nearshore River Mouths Fig. 3. Average percentages of ingested macrophytes by sampling area present in tilapia stomachs sampled at the Salton Sea. Pelagic n = 11, nearshore n = 32, river mouth n = 109. Mean values were calculated from individual stomachs. tows) and the observed plankton percentages (tilapia stomachs) for barnacles, copepods, and rotifers during the summer (p > 0.1), fall (p > O.1), and winter (o> OMe Pieures)): Pile worms and nematodes were highest in the spring and fall (Table 1; Kruskal- Wallis test statistic = 11.1, p = 0.01 (pile worms), 29.6, p < 0.01 (nematodes), 3 df). Ciliates were highest during the summer (Kruskal-Wallis test statistic = 7.0, p < 0.01, 3 df). Pile worms in stomachs were more abundant at the river mouths (Table 1; Kruskal-Wallis test statistic = 7.0, p = 0.03, 2 df). There was no pattern between intestinal color and stomach acidity nor was there evidence of stomach acidity varying according to time of day. Fisher’s LSD post-hoc groupings were spring-summer and fall-winter (Figure 6). Stomach acid- ities were lower during the fall-winter period compared with the spring-summer period (Figure 6; split-plot ANOVA, p = 0.02 for factor season, 104 error df). Discussion Our observations show that the summer at the Salton Sea is a stressful period for tilapia. We commonly observed tilapia in the summer gulping air for oxygen and spending most of their time at the surface (Costa-Pierce and Riedel 2000; Riedel et al. 2002). Water temperature often surpasses 32°C and oxygen inter- mittently drops to zero over large areas during that season. We do not, however, exclude the winter from also being a stressful period for tilapia because water temperatures during winter may drop to their minimum lethal limit (Costa-Pierce and Riedel 2000). The seasonal variation of the sediment quantity in tilapia stomachs indicates that fish spend the least amount of time foraging at the bottom during the summer. The presence of sediment in tilapia stomachs during the summer is indicative that fish can use detritus, despite anoxia at the bottom. Salton Sea tilapia in the summer may venture to the bottom to feed on detritus in the nearshore and quickly return to the surface for oxygen. Tilapia move toward the shore during warm months (Riedel and Costa-Pierce 2002; Costa-Pierce and Riedel 2000), possibly to take advantage of detritus when in shallow water. Another potentially important food source in the summer are the macrophytes drifting into the Salton Sea from the surrounding tributaries. Even though tilapia FEEDING ECOLOGY OF TILAPIA 0) 0 0) 0 0 cO'O x 0 £00 0 0 cO'0 Spose.sO (C80) (PL 1) (Lr'0) Gc) (Ec ©) (19°T) (€6'¢) (6r'0) (O00 1) (Ga) 0 £00 GEV) SLO [v0 STO x 970 90°0 2.1100) cc 0 ke @ SUIOM Id (L9°0) (06>) (780) (6L°0) 0 ILO r0'0 0) 0 O x an) c9'0) 0 0) 0 soyelt) (VCC) (OL'T) (97 T) (dr D WO) (€8'0) (SPC) (C9'p) (L0'0) (870) (er 1) Oc 'O 10°0 9¢°0 STO OS 0 890 x £00 0 S80 8L0 6c 0 SOPO}JVULON] soyjuog (06) (OL'©) (861) (Oil ©) (8L°€) 0) 0 100 0 0 0) x 0) 0 EN O 100 SJOOSU] (061) (00°C) (91°) (6L °C) 0 0 0 0 0 rO'O x 0) 0 0 0) cO'O BIOSOPETD (06'F) 0 0 10°0 0 0 0 x 0 0 0 0 0 spodiydury (VCC) (06h) (Iv 1) (~8°0) (O81) (10) (€¢e0) (L9°0) (CET) (~8'0) cl O 0 cO'0 810 8c 0 CEN) x 98°0 SL0 vVLO ve 0 8c 0 SIOJHOY GG) (91D) (O0'¢) (CEO) (LS°0) (Iv'O) (-6'0) (¢6°0) (00°C) (OVC) r0'0 700 60°0 780 €S°0 8L°0 x 770 €7'0 0 0 80°0 spodado5 (18'T) (ZOO) (96'0) (87°) (OL'b) (09'S) (S81) (€9°C) (780) vcO 860 OS'O ) cO'0 0) x 0 0) 60°0 90°0 6c 0 Sopoeuled uo}yur[doo7 (91°€) ) ) 0 0 0) 0 x 0 0 0 LO'0 0 Saye [[aseyourd (VOC) (L9°0) (TOT) (LO) CEG WD) (SST) (9¢'°T) (00°C) WEEN) (91'¢) Oc 0 SLO OS'O 0 L9'0 cv 0 x ca Se O STO ev 0 6 0 smojeld uo yurldoyAyd (S) (t) (V7) (7) (TI) (v7) (0) (9) (TE) (7) (OL) (6c) =U d N ad d N a d N ad d N a JOVUIAA, Te JOWIUUNS sulids ‘(u) pozAyeuR syoRuIoys Jo AyQUeNb aie stsoyyuored ul sroquinu ‘pojdures Yysy ou — X ‘(o1sejed — g ‘azoysivou — XY ‘yNOU JOATI — y) vare Suljdures pue uosvas Aq padnois oie exe, ‘soyjueq pue ‘uoyyuL{dooz ‘uoyyueydoyAyd 30} Ayayeredas payepnoyed atam suonsodoid uray, *s}Ud]U0D YORUIOYS WOT, POyMUSpl exe) JO (URIL/UONeIADp prepuvis SuONeUeA JO JUaTIOYJo09) uoodoid uespy “] AQeL ies) i) SOUTHERN CALIFORNIA ACADEMY OF SCIENCES 1.2 | C] Rotifers 1 Copepods I FA Barnacles N B 08 = S. Oo 0.6 = jae 7 o 04 rH = rH 0.2 2 Spring Summer Fall Winter Fig. 4. Mean percentages over sampling areas of most frequent zooplankton in the diet of tilapia sampled at the Salton Sea. Differences in mean percentages by sampling area were not statistically significant. Spring n = 43, summer n = 38, fall n = 38, winter n = 33. are not obligate herbivores, the high stomach acidity make tilapia an opportunistic herbivore. The digestibility of plant material in tilapia is not as high as that for true herbivores such as common carp (Cyprinus carpio), but high enough to pro- vide some nutritional benefit (De Silva and Perera 1983). The highest concentra- tion of tilapia in the summer is within the mixing zones between the river mouths and the Salton Sea proper (Riedel and Costa-Pierce 2002; Costa-Pierce and Riedel 2000). Fish seek the lower temperatures and higher dissolved oxygen at those locations. Tilapia may also prefer the river mouths because of the added benefit of macrophyte drift. The importance of the phytoplankton to Salton Sea tilapia may have been underestimated because most phytoplankton cells may have been lost during our filtration or not captured during our plankton tows, due to the large mesh size we used. Our results, however, for the larger phytoplankton show that diatoms are the most important food item. The abundance of diatoms at the Salton Sea de- clines during the summer (Carpelan 1961a). Similarly, diatoms were less abundant in tilapia stomachs during that season. The proportions of barnacles, copepods, and rotifers in fish stomachs correlated well with their proportions in the water column and with the seasonal abundance patterns described in other studies (Car- pelan 1961b; Tiffany et al. 2002). Tilapia species have been known to be unse- lective feeders (Beveridge ef al. 1989). The close agreement between taxa in fish stomachs and taxa in the water column is evidence for low electivity for Salton Sea tilapia when feeding within the water column. Pile worms become restricted to shallow areas of the Salton Sea in the summer due to anoxia and recolonize deeper areas in the fall and winter (Detwiler ef al. 2002). Pile worms in tilapia stomachs increased during the recolonization period, indicating the importance of this food item for tilapia. Ciliates and nematodes were observed in tilapia stomachs and may contribute to the nutritional value of sediment, but are likely not as important as pile worms due to their small sizes. FEEDING ECOLOGY OF TILAPIA 33 100 Barnacles | Stomach | Plankton 60m 80 40 Copepods ‘® Stomach © S oy -* Plankton r= cD) 2 60 fa 40 20 O T Rotifers -# Stomach -* Plankton Summer Fall Winter Fig. 5. Contrast between frequency of barnacles, copepods, and rotifers from tilapia stomachs and from the Salton Sea water column during the summer, fall and winter, 2000. Chi-square of summer = 0.04 (ns), fall and winter = 0.18 (ns); Observed—percentages in tilapia stomachs, Expected— percentages in the water column from plankton tows. The higher occurrence of pile worms in tilapia stomachs from the river mouths may be due to the higher aeration of the sediment at that area. We did not observe a pattern in the color of intestinal material possibly because tilapia do not feed exclusively on plants. Epiphytic algae and aquatic vegetation are low at the Salton Sea, except for macrophytes drifting from the incoming tributaries. Salton Sea tilapia, including specimens at the river mouths, rely mostly 34 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES Stomach pH N Spring Summer Fall Winter Fig. 6. Mean + SEM stomach acidity by season for tilapia stomachs at the Salton Sea. Horizontal bars indicate analysis of variance post-hoc groupings (Fisher’s LSD, p < 0.05; p = 0.02 for factor season, 104 df). on plankton and benthic organisms for food, keeping the color of intestinal ma- terial brown, even if food is not digested. Tilapia at the Salton Sea reproduce from the spring to the end of summer (Riedel et al. 2002). According to our stomach acidity data, tilapia feeding in- creases during fall and winter. In the spring, tilapia are getting ready to reproduce and in the summer tilapia are stressed from anoxia and high temperatures. The critical period for growth may be a short period between the fall and winter before temperatures decrease below suboptimal, and the early spring, before reproduc- tion. During those periods, we observed many fish stomachs full with adult pile worms, further evidence of the importance of this polychaete in determining ti- lapia condition and supporting its population. The Salton Sea recently experienced massive bird mortalities (Tetra Tech 2000). Among the culprits is a bactertum, Clostridium botulinum, which causes botulism in pelicans. Pelican mortality is highest during summer and is possibly mediated by tilapia. Pelicans feed on tilapia infected with the bacterium. Because the bac- terium and its spore are inhibited from growing in acid environments (pH 4.6 or below), we hypothesize that C. botulinum should be more common in tilapia stomachs during the spring and summer, based on the patterns of tilapia stomach acidity found here (Figure 6). The success of Salton Sea tilapia may be attributed to its high feeding plasticity. Fish derive nutritional value from plants and plankton in the summer, but rely mostly on the pile worms during the fall and winter, making those seasons critical for tilapia growth and production. Because of the predominance of pile worms in the sediments during the fall and winter (Detwiler et al. 2002), they are likely responsible for the high growth rates and production of Salton Sea tilapia. Acknowledgments This research has been funded by the United States Environmental Protection Agency through Grant EPA98-013 to the Salton Sea Authority. The research FEEDING ECOLOGY OF TILAPIA 85 results do not necessarily reflect the views of the Agency. No official endorsement should be inferred. We would like to thank the Salton Sea Authority for their generous support of this research, especially Tonie Rockie, Tom Kirk, and Milt Friend. Special thanks are due to Stuart Hurlbert and the SDSU Center for Inland Waters for their support throughout this study. The technical assistance and expertise of W. Chesley Ver- vaeke and Lucy Caskey are especially appreciated. Literature Cited Beveridge, M., Begum, M. Frerichs, G., and Millor, S. 1989. The ingestion of bacteria in suspension by the tilapia Oreochromis niloticus. Aquaculture 81, 373-378. Beveridge, M. and McAndrew, B. 2000. Diet, feeding and digestive physiology. In Tilapias: Biology and Exploitation (Beveridge, M. and Baird, D., eds.) pp. 59-87. Kluwer, Boston. Bowen, S. 1979. A nutritional constrain in detritivory by fishes: the stunted population of Sarotherodon mossambicus in Lake Sibaya, South Africa. Ecol. Monogr. 49, 17-31. 1982. Feeding, digestion, and growth—qualitative considerations. In The Biology and Culture of Tilapias (Pullin, R. and Lowe-McConnell, R., eds.), pp. 141-156. Proc. Bellagio Conf., ICLARM, Manila. Bowen, S. and Allanson, B. 1982. Behavioral and trophic plasticity of juvenile Tilapia mossambica in utilization of the unstable littoral habitat. Env. Biol. Fish. 7, 357—362. Bruton, M. and Allanson, B. 1974. The growth of Tilapia mossambica in Lake Sibaya, South Africa. J. Fish Biol. 6, 701-715. Bruton, M. and Boltt, R. 1974. Aspects of the biology of Tilapia mossambica in a natural freshwater lake (Lake Sibaya, South Africa). J. Fish Biol. 7, 423—445. Carpelan, L. 196la. Phytoplankton and plant productivity. In The Ecology of the Salton Sea, Califor- nia, in Relation to the Sportfishery (Walker, B., ed), pp. 33—42. Cal. Dept. Fish and Game Bull. Lets. Carpelan, L. 1961b. Zooplankton. In The Ecology of the Salton Sea, California, in Relation to the Sportfishery (Walker, B., ed), pp. 49-61. Cal. Dept. Fish and Game Bull. 113. Costa-Pierce, B. and Doyle, R. 1997. Genetic identification and status of tilapia regional strains in southern California. In Tilapia Aquaculture in the Americas, Volume | (Costa-Pierce, B. and Rakocy, J. eds.), pp. 1-21. World Aquaculture Society: Baton Rouge. Costa-Pierce, B. and Rakocy, J. 1997. B. Tilapia Aquaculture in the Americas, Volume 1. World Aquaculture Society: Baton Rouge. Costa-Pierce, B. and Rakocy, J. 2000. B. Tilapia Aquaculture in the Americas, Volume 2. World Aquaculture Society: Baton Rouge. Costa-Pierce, B. and Riedel, R. 2000. Fisheries ecology of the tilapias in subtropical lakes of the United States. In Tilapia Aquaculture in the Americas, Volume 2 (Costa-Pierce, B. and Rakocy, * J. eds.), pp. 1-20. World Aquaculture Society: Baton Rouge. Dempster, P., Beveridge, M. and Baird, D. 1995. Herbivory in the tilapia Oreochromis niloticus: a comparison of feeding rates on phytoplankton and periphyton. J. Fish Biol. 43, 385-392. De Silva, S. and Perera, M. 1983. Digestibility of an aquatic macrophyte by the cichlid Etroplus suratensis (Bloch) with observations on the relative merits of three indigenous components as markers and daily changes in protein digestibility. J. Fish Biol. 23, 675—684. De Silva, S., Perera, M. and Maitipe, P. 1984. The composition, nutritional status and digestibility of the diets of Sarotherodon mossambicus from nine man-made lakes in Sri Lanka. Env. Biol. Fish. 11, 205-219. Detwiler, P, Coe, M., and Dexter, D. 2002. The benthic invertebrates of the Salton Sea: distribution and seasonal dynamics. Hydrobiologia 473: 229-244. Fryer, G. and Hes, T. 1969. Alternative routes to evolutionary success as exhibited by African cichid fishes of the genus Tilapia and the species flocks of the Great Lakes. Evolution 23, 359-369. 1972. The cichlid fishes of the Great Lakes of Africa. TFH: London. Khallaf, E. and Alme-na-ei, A. 1987. Feeding ecology of Oreochromis niloticus and Tilapia zillii in a Nile canal. Hydrobiologia 146, 57—62. Lowe-McConnell, R. 1975. Fish communities in tropical freshwaters. Longman: London. 36 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES Maitipe, P. and De Silva, S. 1985. Switches between zoophagy, phytophagy and detritivory of Sar- otherodon mossambicus populations in twelve Sri Lankan lakes. J. Fish Biol. 26, 49-61. Moriarty, D. 1973. The physiology of digestion of blue-green algae in the cichlid fish Tilapia nilotica. Je Zool, 1715 25-39: Noakes, D. and Balon, E. 1982. Life histories of tilapias: an evolutionary perspective. In The Biology and Culture of Tilapias (Pullin, R. and Lowe-McConnell, R., eds.), pp. 61—82. Proc. Bellagio Conf., ICLARM, Manila. Riedel, R., L. Caskey, and Costa-Pierce, B. 2002. Fisheries biology and ecology of the Salton Sea. Hydrobiologia, 473: 229-244. Sheskin, D. 2000. Handbook of Parametric and Non-Parametric Statistical Procedures. New York: Chapman and Hall. Sokal, R. and E Rohlf. 1995. Biometry. Freeman: New York. Tetra Tech, Inc. 2000. Draft Salton Sea Restoration Project Environmental Impact Statement/Environ- mental Impact Report. Washington, DC: United States Department of the Interior. Tiffany, M. Swan, B., Watts, J. and Hurlbert, S. 2002. Metazooplankton dynamics in the Salton Sea, California, 1997-1999. Hydrobiologia 473: 103-120. Walker, B., R. Whitney, and G. Barlow. 1961. Fishes of the Salton Sea. In The Ecology of the Salton Sea, California, in Relation to the Sportfishery (Walker, B., ed), pp. 77-92. Cal. Dept. Fish and Game Bull. 113. Winer, B., Brown, D., and Michels, K. 1991. Statistical Principles in Experimental Design. New York: McGraw-Hill. Wooton, R. 1998. The Ecology of Teleost Fishes. Kluwer, London. Accepted for publication 26 of May, 2004. Bull. Southern California Acad. Sct. 104(1), 2005, pp. 37—43 © Southern California Academy of Sciences, 2005 Microhabitat Segregation of ‘Three Species of Pocket Mice (Genus Chaetodipus) in Coastal Baja California, Mexico Paul Stapp Department of Biological Science, California State University, Fullerton, California 92834-6850 U.S.A. Abstract.—I compared vegetation and substrate characteristics at capture locations of three syntopic species of pocket mice (Chaetodipus: Heteromyidae) to deter- mine differences in microhabitat affinities of these ecologically similar rodents in coastal Baja California, México. Principal components analysis revealed that cap- ture locations of C. spinatus had disproportionately higher cover of medium and large rocks, and tended to have higher plant species diversity than capture loca- tions of the other two species. C. spinatus and C. arenarius, the two smallest species, differed most in their microhabitat affinities, suggesting spatial segrega- tion that may minimize competition for similar food resources. C. arenarius was captured most often at sites with the finest-textured soils, whereas C. rudinoris, the largest species, was widespread and frequently associated with gravel and small rocks. No species showed any apparent preference for plant species or significant amounts of overhead cover, a conclusion supported by the high den- sities of C. rudinoris on small, barren islands in the Gulf nearby. My results represent the first quantitative descriptions of the habitat associations of these species, which are wholly or predominantly restricted in their distributions to Baja California. Studies of desert rodents have provided important insights into the mechanisms that permit species coexistence (Kotler and Brown 1988; Brown and Harney 1993). Desert rodent communities are often incredibly diverse, containing as many as 14 species, and in the case of North American deserts, are dominated by granivorous heteromyids (Brown and Harney 1993). The co-occurrence of mul- tiple, ecologically similar heteromyid species has been attributed to subtle differ- ences in diet (e.g., Brown and Leiberman 1973; M’Closkey 1978), foraging ef- ficiency (Price and Heinz 1984; Price and Waser 1985; Brown 1989), predator escape abilities (Kotler 1984; Longland and Price 1991) and body size (Bowers and Brown 1982), all of which reflect the long-term consequences of competition, predation risk and biogeographical history (Brown and Harney 1993). These dif- ferences usually are manifest in patterns of microhabitat use (e.g., Price 1978; Wondolleck 1978; Thompson 1982), with species separated locally in space by the amount and species composition of plant cover and soil and substrate char- acteristics (Reichman and Price 1993). | As part of a study of the ecology of coastal and insular populations of rodents in northern Baja California, I captured three species of pocket mice (Chaetodipus arenarius, C. rudinoris and C. spinatus) in very close proximity to one another, at locations with seemingly similar vegetation and substrate features. I recorded microhabitat characteristics at capture locations of each species to look for evi- ey 38 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES dence of microhabitat partitioning that might explain the co-occurrence of these otherwise ecologically similar species, which comprise approximately 75% of captures of rodents in the study area (Stapp and Polis 2003). These species have their distributions either wholly (C. arenarius) or predominantly (C. spinatus, C. rudinoris) in Baja California (Lackey 1991a, b; Paulson 1988), yet little is known of their ecology outside of the general habitat descriptions provided in taxonomic references (e.g., Burt 1932; Huey 1964). Riddle et al. (2000) recently proposed that populations of C. baileyi west of the Colorado River are a distinct species, C. rudinoris. To my knowledge, this study provides the first quantitative descrip- tions of the habitat affinities of these species. Methods The study was conducted from May—October 1998 in a wide desert bajada located 10 km north of Bahia de los Angeles, along the Gulf coast of Baja Cal- ifornia, México. Vegetation is Sonoran desert scrub and dominated by perennial shrubs (Bursera hindsiana, B. microphylla, Fouquieria spp., Lycium spp., Larrea tridentata, Jatropha cuneata), short trees (Olneya tesota, Pachycormus discolor, Cercidium microphyllum) and cardons (Pachycereus pringlei). Frankenia palmeri, Suaeda moquinii and Salicornia subterminalis are the dominant plants in a narrow zone of fine-textured soil 50—75 m from the shore. The beaches adjacent to the study area were covered with smooth cobble. Annual plants were abundant inland in the spring of 1998, following a strong 1997—98 El Nino Southern Oscillation event that brought 440 mm of rain to the area, which normally receives <59 mm annually (Stapp and Polis 2003). In May 1998, I established two 1|.5-ha trapping grids, separated by approxi- mately | km. Grids consisted of 54 trap stations, with six parallel transects orig- inating in the supralittoral zone and extending inland perpendicular to the shore for 200 m. Transects were 15 m apart and consisted of nine stations spaced at 25-m intervals. Each trap station had a single Sherman live trap, which was baited with peanut butter and oats. The size of the grid was reduced to four transects in October 1998 (36 traps; 0.9 ha). Rodents were live-trapped for three consecutive nights in May and October 1998, but because feral dogs disturbed many traps on the third night, I used only data from two nights of trapping in each session to estimate species composition and relative abundance. Traps were opened at dusk and checked and closed at dawn each morning to prevent heat-induced mortality. Each individual captured was measured, weighed and given a uniquely numbered aluminum ear tag. All individuals were released at their capture location. I used the number of individ- uals captured per unit trapping effort as an index of relative abundance. Vegetation and substrate characteristics were recorded within a 3-m radius plot of each trap station where different Chaetodipus were captured, omitting recap- tures of the same individual at the same station. I recorded the number of species of trees (=2 m in height), shrubs, and ground cover plants (mostly annuals), and estimated visually the percentage canopy cover of plants in the plot. I character- ized the percentage cover of each type of substrate within each plot, using the following categories: sand; marine silt; small rocks (ca. 2—10 cm diameter); me- dium rocks (10—30 cm); large rocks (>30 cm). Another observer and I estimated percentage cover of plants and substrate independently, and the mean of these MICROHABITAT USE OF BAJA CALIFORNIA POCKET MICE 3) Table 1. Relative abundance [number of individuals/100 trap-nights (TN)] of rodents on two, 1.5- ha coastal study areas near Bahia de los Angeles, Baja California, México in 1998. The number of unique trap stations used denotes the number of different trap stations where each species was captured. Mean abundance was calculated for May and October trap sessions on each site; values presented are the means + | s.e. of the two study areas. For comparison, 44% of all trap stations were =75 m from shore. Body weights are means + | s.e., with n in parentheses, based on live-trapping on the mainland between 1997-2001 (P. Stapp, unpubl. data). No. of Percent No. unique of capture Adult body individuals Relative trap locations weight (total abundance stations = 7/5100) Species (g) captures) (No./100TN) used — from shore Chaetodipus rudinoris 925,04, 69) 49 (59) 14.34 + 4.69 42 40.48 Chaetodipus spinatus 1520.22 10:3 (50) 42 (43) 14.69 + 1.25 34 17265 Chaetodipus arenarius ae, =O (25) Lord7) 323) 20/011 16 50.00 Dipodomys merriami SAD = 120 (U's) 16 (19) Seog 23. 14 57.14 Peromyscus eremicus G22) = O50E1'7) 7 (8) Dd = 10:30 8 37-50 Neotoma lepida LSS. 75710110) 7 (9) 22.4 a6 if Sov estimates was used in data analysis. Principal components analysis was used to reduce the number of correlated variables for comparisons of differences in mi- crohabitat associations of each species. Within each plot, I also recorded presence of mounds with extensive burrow systems to evaluate the efficacy of using these burrow networks as an indicator of species presence. Results Six rodent species were captured on both study sites (Table 1). As in other Sonoran Desert communities, heteromyids were numerically dominant. Sigmo- dontine rodents (Peromyscus eremicus, Neotoma lepida) were captured only oc- casionally and represented by few individuals. Chaetodipus spinatus and C. ru- dinoris were most abundant and captured in approximately equal numbers, where- as C. arenarius and Dipodomys merriami were less common. Although all species except D. merriami were captured in traps in the supralittoral zone, C. spinatus was largely restricted to scrub vegetation far from shore (Table 1). In contrast, C. rudinoris and C. arenarius were dispersed fairly uniformly across the trapping areas. N. lepida, an herbivorous species typically associated with rocky slopes and outcrops, was restricted primarily to the dense Salicornia and Suaeda cover near shore (Table 1). C. formosus is known to be present in the area (Stapp 2002; G. Stewart, pers. comm.), but was not caught on the study sites during my study. Analysis of microhabitat variables at capture locations suggested differences among species in their affinities for local substrate and soil characteristics. Four principal components had eigenvalues >1.0, with the first principal component axis (PC1) accounting for nearly 28% of the variance (Table 2). The three species differed only in their scores for PCI (Kruskal-Wallis test, x? = 9.20, d.f. = 2, P = 0.01; all other PC axes, P > 0.19). Capture stations of C. spinatus had signif- icantly higher mean scores for PC1 (mean + 1 s.e. = 0.65 + 0.25) than those where C. rudinoris (—0.33 + 0.21) and C. arenarius (—0.52 + 0.31) were caught. Based on the correlations between microhabitat variables and PC1 (Table 2), cap- ture locations of C. spinatus were significantly more rocky (.e., had proportion- SOUTHERN CALIFORNIA ACADEMY OF SCIENCES 40 ‘SUIISAUDAA DULIDIW ‘AAW {uuowuaas vajog “Aswad ‘dds viqsoydny ‘HdNd ‘S1uoisuasspp vpusuy ‘QVaV ‘k4owa asad “WAAd > ‘DIDINNUIB DOUIDISIA “AOTA ‘pypaund vYydoAOL ‘YOVWE {SYDUNUAAIQNS VIULOINVS ‘YSWS ‘Mumnbou ppavng ‘OWNS ‘Pvluapltl VasIVT “YLT dds wnosT “‘TOXT ‘MMauypd DIUaYUDAY “WAA ‘1aj8uldd SNaAIAIKYIVD “WdWd swnppdydosou UINIPIIAAD ‘YWWAOD {v10sa1 vkaujQ “AITO :e7Xydosonu dsasing ‘TWO ‘euvispuiy vaasang “TWwod ‘dds pidainbnoy GSOdq ‘40/09SIp snwus0gKyIVd “TqVd ee 90° 1 ISO] GEC EMEC poure[dxs sourLiea % Gli (Gall 6L I Ic? onjeaussiq AYVW AAVW “ASVd AAVW SAVd ‘HdNd ‘dvuav Wadd ‘HdNdA “dVaVv Wadd ‘HdNd “dVaVv Wadd ssatoeds Aroyssopun soley NOV! INN ADIA ASVS ‘OWNS ULVT TOAT “Vda DOVE ALVA 1A “ULV T IOAT Vdd gseroeds qniys soley UdVd ‘INA ALTO ‘IWNd dSOd 1dVd ‘THN dSOd IdVd THNd dSOd TdVd satsads sen Iofey br0 Or 0— STO Gci0 ISt + 6c CII + 60°€ 60°; + LIV YOO I5Ie] % 60°0— 6r 0 cL O Lv'0 CLC + 6S S87 + SECT LL3 + 69°¢ YSOI WnIpsus % ENO LvO0S 0o10= a 0) ely + 9C Tl 6S + 88°SI vOV + CLT YSOr [euls % 90°0 S11) OVO vs 0- C8'S + SLBL CVS + ESBS ITS + 18°89 iTS JO pues % 6S 0 9¢°0 he == 60 = ver + v6o0e 80 + CL Ic 6L¢C + LO LT Jaaoo yueld % Oks Vs SOS 6V 0 170 OS'O + 88°C LTO + 16'€ 9¢°0 + OI satseds Aro\siepun “ON 0C0= Os 0 GAS ce 0 970 + 881 ECO" Cl LTO + 881 sarseds qniys “ON Os 0 SOL0= 960 cv 0 ClO +/Te0 ITO + 0° 0 ITO + OVO soroeds 90 ‘ON pod COd GDA ia SNIADUAAD “dD snypuids “D SIMOUIPNA “D JIQVLIBA JeILQeYOIOIY SUONPIALIOD Od ee eS... wy na—_<——s>+ “‘SONsLIa}ORIeYS deIsqns pur UONRIDSIA SuIquOsap sofqeleA pur CQ’ < sSonfeAuasia YUM syusuoduros [edrourid moj UsaMjoq SUONR[SHOS ste SUUINTOS ANOJ Ise] CYL ‘sotoads UdAIs & JO suoNeoo] ainjded Jo %OZ= Ie Jasaid asoy} osaM past] sorsods queyd sofew sy ‘({ aIqeL) setoads yove Aq pasn suoneys dex onbrun jo saquinu 94} si ozs ojduies ‘OOIXa| ‘eIUIOJTTeO eleg ‘sajasuy soy op vIyeg Jwou sndipojapyD Jo satdads sa1y} JO suOMedo] oinjdeo Jo (‘A'S [| F USUI) SONSHa}oBFeYS YIUqeyo1oyA, “C PIPL MICROHABITAT USE OF BAJA CALIFORNIA POCKET MICE 4] ately less fine-textured soil) and tended to have overall higher plant species di- versity than those of the other two species. This interpretation is supported by inspection of the mean values of the microhabitat variables separately (Table 2). However, capture locations of the three species tended to be dominated by the same plant species. The presence of Frankenia, Suaeda and Salicornia at capture locations of C. rudinoris and, to a lesser extent, C. arenarius, reflected the fre- quent captures of these species in coastal vegetation. The degree of overlap among captures of the three Chaetodipus species pro- vides additional evidence of differential microhabitat use by the two smallest (and presumably, most similar ecologically) species. C. rudinoris and C. spinatus were often captured at the same trap (36% and 44% of C. rudinoris and C. spinatus captures overlapped, respectively), but C. spinatus rarely overlapped with the smaller C. arenarius (12% and 25% of C. spinatus and C. arenarius captures, respectively). In inland areas where C. spinatus was most abundant, C. arenarius was restricted to the sandy bottoms of dry washes. Mounds with extensive burrow networks were present at 26-35% of capture locations of Chaetodipus, which implies that the presence of mounds is not a reliable indicator of trap success. Capture locations with these mounds were al- ways associated with C. spinatus or C. rudinoris, and mounds were present at several locations where only one of these species was captured, suggesting that both build mounds. In contrast, all C. arenarius capture locations with mounds were trap stations where other species were also captured, suggesting that C. arenarius does not construct these mounds. Discussion Three species of pocket mice were captured in close proximity to one another, and often, at the same locations, in two trapping areas in coastal Baja California. There were no obvious differences among species in plant cover or species com- position at capture locations, although areas inhabited by C. spinatus tended to have higher overall plant diversity than capture locations of the other two species. All species were captured frequently in locations with little overhead cover (>50% of capture locations had <20% plant cover). The two smallest species differed primarily in their preference for different substrates, with C. arenarius being restricted to the finest-textured soils, and C. spinatus associated with a mixture of substrates that included more medium and large rocks. C. rudinoris, the largest pocket mouse locally (Table 1), was also the most widespread, and was clearly more generalized in its microhabitat affinities. Both C. rudinoris and C. arenarius were captured frequently in coastal vegetation, the latter in sand and fine marine silt, and the former in areas with gravel and small stones. The ability of C. rudinoris to use gravelly substrates has been reported previously for the closely related C. baileyi (Rosenzweig and Winakur 1969; Price 1978; Wondol- leck 1978), and may explain the persistence of C. rudinoris on small (<0.2 km? area) islands just offshore (Lawlor et al. 2002). Although islands in Bahia de los Angeles are extremely rocky and sparsely vegetated, C. rudinoris maintains high population densities on these islands (Stapp and Polis 2003). Interspecific differences in substrate affinities may reflect differences in relative foraging efficiencies of the three species, as well as variation in the number and size distribution of seeds among microhabitats (Reichman 1984). Unfortunately, 42 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES these data are lacking for my study area and the three species I studied. Laboratory experiments (Price and Heinz 1984) suggested that heteromyids, regardless of size and morphology, forage most efficiently when seed densities are high and soils are sandy. However, C. baileyi, the close congener of C. rudinoris, and Perognathus amplus, which is similar in size and morphology to C. arenarius (Table 1; Price and Heinz 1984), differed in their preferences for seilmtextuner with C. baileyi preferring coarse soils and P. amplus extracting more seeds from fine-textured soils (Price and Waser 1985). In my study, C. arenarius and C. rudinoris seemed to overlap in their microhabitat associations, but they may select soul characteristics on a finer scale than could be detected by my sampling meth- ods. However, given the large difference in body size (9 g; Table |) between these two species, they may also have distinct preferences for different sizes or spatial distribution of seeds that may explain their co-occurrence. More information on the density and accessibility of seeds in rocky substrates, on the foraging behavior of C. spinatus, and on possible competitive effects of C. rudinoris on the smaller pocket mice is needed to assess patterns of spatial overlap in this system. Acknowledgements I am grateful for the assistance of A. Subalusky in the field, and to P. West for help with plant species identification. The Mexican government provided scien- tific, logistic and diplomatic support of our research (DAN-022201, -00722, -01529, -00963, -01542, -01909 and supporting documents). Field research was supported by a grant from the National Science Foundation (DEB-9806657) to G. A. Polis and P. Stapp. Literature Cited Bowers, M. A. and J. H. Brown. 1982. Body size and coexistence in desert rodents: Chance or community structure? Ecology, 63:391—400. Brown, J. H. and B. A. Harney. 1993. Population and community ecology of heteromyid rodents in temperate habitats. 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A. 1991b. Chaetodipus spinatus. Mamm. Species, 385:1—4. Lawlor, T. E., D. J. Hafner, P. Stapp, B. R. Riddle, and S. T. Alvarez Castattieda. 2002. Mammals. Pp. 326-361 in: A New Island Biogeography in the Sea of Cortés (T. J. Case, M. L. Cody and E. Ezcurra, eds.). Oxford Univ. Press, Oxford, 653 pp. Longland, W. S. and M. V. Price. 1991. Direct observations of owls and heteromyid rodents: Can predation risk explain microhabitat use? Ecology, 72:2261—2273. M’Closkey, R. T. 1978. Niche separation and assembly in four species of Sonoran Desert rodents. Am. Nat., 112:683—694. MICROHABITAT USE OF BAJA CALIFORNIA POCKET MICE 43 Paulson, D. D. 1988. Chaetodipus baileyi. Mamm. Species, 297:1-—5. Price, M. V. 1978. The role of microhabitat in structuring desert rodent communities. Ecology, 59: 910-921. Price, M. V. and K. M. Heinz. 1984. Effects of body size, seed density, and soil characteristics on rates of seed harvest by heteromyid rodents. Oecol., 61:420—425. Price, M. V. and N. M. Waser. 1985. Microhabitat use by heteromyid rodents: effects of artificial patches. Ecology, 66:211—219. Reichman, O. J. 1984. Spatial and temporal variation of seed distributions in Sonoran Desert soils. J. Biogeogr., 11:1—11. Reichman, O. J. and M. V. Price. 1993. Ecological aspects of heteromyid foraging. Pp. 539-574 in: Biology of the Heteromyidae (H. H. Genoways and J. H. Brown, eds.). Spec. Publ. No. 10, Amer. Soc. Mammalogists, Stillwater, OK, 714 pp. Riddle, B. R., D. J. Hafner and L. EF Alexander. 2000. Comparative phylogeography of Baileys’ pocket mouse (Chaetodipus baileyi) and the Peromyscus eremicus species group: Historical vicariance of the Baja California Peninsular Desert. Molecular Phylogen. Evol., 17:161—172. Rosenzweig, M. L. and J. Winakur. 1969. Population ecology of desert rodent communities: Habitats and environmental complexity. Ecology, 50:558—572. Stapp, P., and G. A. Polis. 2003. Influence of pulsed resources and marine subsidies on insular rodent populations. Oikos, 102:111—123. Thompson, S. D. 1982. Microhabitat utilization and foraging behavior of bipedal and quadrupedal heteromyid rodents. Ecology, 63:1313-—1321. Wondolleck, J. T. 1978. Forage-area separation and overlap in heteromyid rodents. J. Mamm., 59: 510-518. Accepted for publication 16 September 2004. =, i ee INSTRUCTIONS FOR AUTHORS The BULLETIN is published three times each year (April, August, and December) and includes articles in English in any field of science with an emphasis on the southern California area. Manuscripts submitted for publication should contain results of original research, embrace sound principles of scientific investigation, and present data in a clear and concise manner. The current AIBS Style Manual for Biological Journals is recommended as a guide for contributors. Consult also recent issues of the BULLETIN. 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Such illustrations along with a brief caption should be sent to the Editor for review. PROCEDURE All manuscripts should be submitted to the Editor, Daniel A. Guthrie, W. M. Keck Science Center, 925 North Mills Avenue, Claremont, CA 91711. Authors are requested to submit the names, addresses and specialities of three persons who are capable of reviewing the manuscript. Evaluation of a paper submitted to the BULLETIN begins with a critical reading by the Editor; several referees also check the paper for scientific content, originality, and clarity of presentation. Judgments as to the acceptability of the paper and suggestions for enhancing it are sent to the author at which time he or she may be requested to rework portions of the paper considering these recom- mendations. The paper then is resubmitted on disk in word format and may be re-evaluated before final acceptance. Proof: The galley proof and manuscript, as well as reprint order blanks, will be sent to the author. He or she should promptly and carefully read the proof sheets for errors and omissions in text, tables, illustrations, legends, and bibliographical references. He or she marks corrections on the galley (copy editing and proof procedures in Style Manual) and promptly returns both galley and manuscript to the Editor. Manuscripts and original illustra- tions will not be returned unless requested at this time. All changes in galley proof attributable to the author (misspellings, inconsistent abbreviations, deviations from style, etc.) will be charged to the author. Reprint orders are placed with the printer, not the Editor. CONTENTS Biological Assessment of Tecate Creek (U.S.—Mexico) with Special Regard to Self-Purification. Volker Ltderitz, Frauke Gerlach, Robert Jiipner, Jesus.Calleros, Jerome Pitt, and Richard M. Gersbere, 0 ee Age and Growth of Spotted Sand Bass, Paralabrax maculatofasciatus, in Bahia de Los Angeles, Baja California, Mexico, with Age Validation using Otolith Edge Analysis. Allen H. Andrews, Edward A. Laman, Tony Bennett, Erin Jones, and Gregor MM. Cailliet 2 eee Feeding Ecology of Salton Sea Tilapia (Oreochromis spp.) Ralf Reidel and Barry A. Costa-Preree ie ee Microhabitat Segregation of Three Species of Pocket Mice (Genus Chaetodipus) in Coastal Baja California, Mexico. Paul Stapp. Cover: Map of Tecate Creek, U.S.-Mexican Border. See Liideritz, et. al. 14 26 ‘Serials | ISSN 0038-3872 QH 1 S69 v.104 no.2 24116-30 PeUltHERN CALIFORNIA ACADEMY’ OF SCIENCES BOLLETIN Volume 104 Number 2 AU Ranier feat iia — BCAS-A104(2) 45-112 (2005) JUL 1 1 dluo August 2005 LIBRARY Southern California Academy of Sciences Founded 6 November 1891, incorporated 17 May 1907 © Southern California Academy of Sciences, 2005 OFFICERS John Dorsey, President Brad Blood, Vice-President John Roberts, Secretary Daniel A. Guthrie, Treasurer Daniel A. Guthrie, Editor Ralph G. Appy, Past President Robert Grove, Past President David G. Huckaby, Past President Daniel J. Pondella, II, Past President BOARD OF DIRECTORS 2003—2006 2004—2007 2005—2008 M. James Allen Brad Blood Jonathan N. Baskin John H. Dorsey Donald G. Buth John Roberts Judith Lemus Robert S. Grove Gloria J. Takahashi Karen Martin Kathy Keene Andrea Murray Susan Yoder Edith Reed Pnicippa Drennan Membership is open to scholars in the fields of natural and social sciences, and to any person interested in the advancement of science. Dues for membership, changes of address, and requests for missing numbers lost in shipment should be addressed to: Southern California Academy of Sciences, the Natural History Museum of Los Angeles County, Exposition Park, Los Angeles, California 90007-4000. Professional Members: 2 4.02 hse. a a, SS a ee ee Student Memibers.. 6. 540k wie a ae et sl Memberships in other categories are available on request. Fellows: Elected by the Board of Directors for meritorious services. The Bulletin is published three times each year by the Academy. Manuscripts for publication should be sent to the appropriate editor as explained in “Instructions for Authors” on the inside back cover of each number. All other communications should be addressed to the Southern California Academy of Sciences in care of the Natural History Museum of Los Angeles County, Exposition Park, Los Angeles, California 90007-4000. Date of this issue 1 August 2005 This paper meets the requirements of ANSI/NISO Z39.48-1992 (Permanence of Paper). Bull. Southern California Acad. Sci. 104(2), 2005, pp. 45-62 © Southern California Academy of Sciences, 2005 Color Patterns and Associated Behaviors in the Kelp Bass, Paralabrax clathratus (Teleostei: Serranidae) Brad E. Erisman! and Larry G. Allen? Nearshore Marine Fish Research Program, Department of Biology, California State University, Northridge, California 91330-8303, U.S.A. Abstract.—Seasonal and ephemeral color patterns in the kelp bass, Paralabrax clathratus, were studied on Santa Catalina Island, California from April 2000 to September 2002. Adults were monochromatic for part of the year (calico phase) and sexually dichromatic from April to October, with most adult males adopting bright orange snouts (OS phase). The seasonal occurrence of the OS phase in males overlapped with the spawning season, and the color was limited to ripe males. The OS phase in ripe males may function as a signal of sexual identity and sexual readiness to females. Both males and females exhibited distinct color patterns during courtship and spawning periods. During these periods, males were charcoal colored with dark black bars overlaying white spots (checkered phase), and females were often black with no visible spots (dark phase). Color patterns displayed by adults during spawning activities may facilitate mate signaling and the formation of spawning groups. Specific color patterns were also observed in relation to habitat and aggressive behaviors. Fishes are unique among vertebrates in their ability to display a wide variety of permanent and temporary color patterns, which are believed to be important in both social and environmental interactions (Townsend 1929; Cott 1940; Lorenz 1962). Some species exhibit permanent sexual dichromatism, where different col- or patterns are adopted for each sex and retained for life (DeMartini 1985; Kodric- Brown 1998). Conversely, monochromatic fishes often exhibit patterns of seasonal sexual dichromatism during the spawning season, and these color patterns are only adopted by actively breeding individuals (Thresher 1984; Kodric-Brown 1998). Ephemeral color changes, which usually persist for only brief periods of seconds to minutes, are widespread among fishes and occur under a variety of conditions including courtship, agonistic interactions, feeding, and changes in hab- itat (Losey 1976; Thresher and Moyer 1983). Color patterns have often been used as key characters for identifying species within the family Serranidae (Heemstra and Randall 1993). Permanent dichro- matism has not been described in the Epinephelinae but is common in the An- thiinae in association with sex change and sexual dimorphism (Shapiro 1981). Among serranines, permanent dichromatism has been reported in at least two species, black sea bass, Centropristes striatus, and barred serrano, Serranus psit- tacinus (Lavenda 1949; Hastings and Petersen 1986). Seasonal and ephemeral ' Current address: Scripps Institution of Oceanography, Marine Biology Research Division, UCSD, 9500 Gilman Drive, La Jolla CA, 92093-0208, U.S.A. ? Corresponding author, larry.allen@csun.edu, (818) 677-3340. 45 46 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES color changes in serranids are well known and are most commonly associated with the social behavior (1.e. courtship, aggression) of groupers (Colin 1992; Gil- more and Jones 1992; Sadovy et al. 1994), and color change has also been related to habitat (Townsend 1929; Smith 1971; Nemtzov et al. 1993). Investigations of color changes and associated behavior in serranines have focused mainly on two genera, Serranus and Hypoplectrus, both of which have tropical distributions (Clark 1959; Thresher 1984; Hastings and Petersen 1986). Color patterns and associated behaviors of temperate serranines are poorly un- derstood, although brief descriptions of sexual dichromatism have been reported in the genus Paralabrax. Male P. maculatofasciatus (spotted sand bass) adopt a pale body color with white chins during the spawning season, where as females become darker in coloration with yellow chins (Allen et al. 1995). During spawn- ing, male P. maculatofasciatus often adopt a high-contrast body coloration con- sisting of dark vertical bars overlaying a white body background (Muller 2004). In P. nebulifer (barred sand bass), breeding males are a high-contrast gray and white color, and they develop golden-yellow crescents below their eyes that are not well developed in females (Allen and Hovey 2001). Other members of the genus exhibit permanent sexual dichromatism. Adult male P. loro (parrot sand bass) have bright orange dorsal fins and cheeks, and the females have red dorsal fins and cheeks (Thomson et al. 2000). The functional significance of color change has not been examined in most serranids, including members of the genus Paralabrax, although color changes are believed to serve a similar purpose in all. Temporary color changes, whether seasonal or ephemeral, are usually associated with specific behaviors, where they function as social signals of motivation (Losey 1976; Thresher 1984; DeMartini 1985). Moreover, distinct color patterns, when coupled with courtship behavior, may enhance the conspicuousness of the color, thereby serving to attract the at- tention of potential mates (Thresher 1984; Kodric-Brown 1998). The combination of certain color patterns and display behaviors by adults may also convey infor- mation on their sexual identity and physiological state (Thresher and Moyer 1983). The kelp bass, Paralabrax clathratus, is a temperate serranine fish that inhabits the nearshore, rocky-reef environments of southern California and northern coast of Baja California (Quast 1968; Miller and Lea 1972). Historically, the species has been an important component of local fisheries, which has led to a number of studies on various aspects of its biology (e.g. Quast 1968; Smith and Young 1966; Love et al. 1996). Histological evidence and sex-specific size frequency distributions of P. clathratus indicate a gonochoric sexual pattern, and no evi- dence of sex change has been reported (Smith and Young 1966; Oda et al. 1993). Recent studies by Erisman (2003) indicate that spawning occurs in single female, multi-male groups of 3 to 20 individuals within large breeding aggregations that form from late spring to early fall. Several hundred adults may aggregate in a small area during spawning. Spawning begins at sunset and occurs for several hours past dark. Unlike many tropical serranids, spawning in P. clathratus occurs continuously throughout the summer months and does not follow a lunar or semi- lunar rhythm (Erisman 2003). The first scientific documentation of color changes in P. clathratus appeared in Quast (1968), who noticed that some males became “‘golden on the snout”’ during COLOR PATTERNS IN KELP BASS AT the breeding season. This color pattern was most frequently observed in small males, although the color was present in some larger males. Similar results were reported by Turner et al. (1969). These early observations suggested that P. clath- ratus were seasonally dichromatic, although the descriptions were vague and no systematic investigations of the color patterns or their relation to the spawning season were ever conducted. The purpose of the current investigation was three-fold: 1) to document and describe seasonal and ephemeral color patterns in P. clathratus, 2) to record and describe behaviors associated with specific color patterns, and 3) to compare the color patterns of collected individuals by sex and reproductive condition. This study represents the first complete description of color changes and related be- haviors in a temperate serranine fish. Materials and Methods Hook and Line Sampling Eight hundred twenty-five individuals (365 males, 397 females, 63 juveniles) were collected by hook and line from May 2001 to April 2002 at several sites along the coast of Santa Catalina Island, California (33° 26’ N, 118° 29’ W) (Figure 1). In addition, 60 individuals were collected by hook and line in San Pedro, California on February 2002 (Figure 1). Collections were made on a monthly basis during the non-spawning season and daily during the spawning season. Standard length (SL) of each individual was recorded to the nearest mm and body weight was recorded to the nearest g. Time and date of collection and the lunar phase were recorded. Macroscopic inspections of gonads were used to determine sex and maturity states of individuals (Hunter and Macewicz 1985; DeMartini 1987; Allen et al. 1995). When the determination of sex was uncertain, gonads were examined under a dissecting microscope for verification (Allen et al. 1995). Gonads were removed from all captured individuals and wet weights were recorded to the nearest 0.5 g. The gonosomatic index (GSI) of adults and visual determinations of gonad maturity states were used to estimate the annual spawning season (Quast 1968; Sadovy et al. 1994; Rhodes and Sadovy 2002). GSI values for individuals were calculated by the following: GSI = (gonad weight/gonad-free body weight) x 100. Monthly variations in male and female GSI were analyzed using a Kruskal- Wallis test (nonparametric ANOVA), as these data did not conform to the as- sumptions of parametric analyses. Swollen ovaries containing eggs enlarged with water and having clear yolks were classified as hydrated. Hydration was verified by comparing the mean GSI of hydrated ovaries with non-hydrated, ripe ovaries using an unpaired t-test. This data set conformed to the assumptions for performing parametric analyses. Hy- drated ovaries were expected to have higher GSI values than non-hydrated, ripe ovaries (Hunter et al. 1985; Hunter and Macewicz 1985). Since spawning occurs in Paralabrax within 24 hours of hydration (Oda et al. 1993), dates on which hydrated females were collected were used as daily markers of spawning (Hunter and Macewicz 1985). These data were organized chronologically and combined with GSI data to estimate the duration of the spawning season in 2001. All collected individuals were identified with respect to both body coloration and head coloration. Individuals were categorized for head coloration according 48 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES 118° 30° W < —— ; LONG BEACH 2 tlie NEWPORT. BEACH \¢ QyCe MARINE 0 SCIENCE HARBORS CENTER HARBOR. @ iniake Pipes Pumpernicke? Cove [] Glue Cavern ©) Habitat Reat A Net Pen Reserve Goundary Fig. |. A Map of Santa Catalina Island, California, showing study sites and proximity to the southern California mainland. Behavioral observations were conducted at several sites inside (Habitat Reef, Intake Pipes, Pumpernickel Cove) and outside (Bird Rock, Blue Caverns) the no-take marine reserve adjacent to the USC Wrigley Marine Science Center. Visual transects were conducted at the Intake Pipes site and the Pumpernickel Cove site. The captive study was conducted at the net-pen site, located on the southwest region of Catalina Harbor. to the presence or absence of a golden to orange coloration on the snout. Indi- viduals with any visible evidence of the coloration were defined as orange-snout (OS) phase (Figure 2a). Individuals showing no visible evidence of a golden to orange coloration were defined as calico phase (Figure 2c). No distinctions were made among OS phase individuals with respect to intensity or coverage of the coloration. Once it was determined that body coloration did not differ among collected males and females, later specimens were only identified with respect to snout coloration. The OS phase was compared by gender, month of observation, ripeness state, time period, and lunar phase. Absolute frequencies were compared Statistically using Pearson chi-square goodness-of-fit tests. The GSI and standard length of collected ripe males were compared by color phase using a Mann- Whitney test, because data did not conform to the assumptions of parametric analyses. Visual Transects Monthly visual SCUBA transects were conducted at two sites, Intake Pipes and Pumpernickel Cove, at Santa Catalina Island (Figure 1) while on SCUBA from COLOR PATTERNS IN KELP BASS 49 Fig. 2. Common color patterns in the Kelp Bass (Paralabrax clathratus). A = OS phase, B = checkered phase, C = calico phase, D = dark phase, E = marbled phase. December 2001 through July 2002. Fixed transects 100 m in length were estab- lished at both sites at 9 m and 18 m depth. Dive surveys consisted of two divers swimming approximately 2 m above the bottom and 3 m apart from one another, counting all adults within 3 m while swimming along the transect. All individuals with estimated lengths of 220 mm TL or greater were identified as adults (Love et al. 1996). Adults were classified based on the presence/absence of orange snout coloration. Individuals with visible evidence of an orange snout coloration where identified as OS phase. Individuals showing no visible evidence of the OS color phase were identified as calico phase. When snout color could not be accurately determined, those individuals were not included. No depth effect was detected, so data were pooled for depth at both sites. None of the collected or observed immature individuals (< 220 mm TL) exhibited the snout coloration and these were excluded from further analyses. Transects were only conducted when visibility levels exceeded 7 m to avoid possible errors related to poor visibility. Transects were conducted on consecutive days for each site. The frequency of individuals with orange snouts was defined as an average of individual frequencies observed per transect by the two divers. All dives were made between 1100—1400 hours to ensure maximal light levels and to eliminate variation in color patterns due to time of day. Variations in the proportion of OS males observed on transects at both sites were compared by month using a Pearson chi-square goodness of fit test. Behavioral Observations Behavioral patterns were documented based on approximately 450 hours of SCUBA or snorkeling observations from April 2000 to September 2002. Visual 50 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES observations were recorded on plastic slates, and digital video recordings of be- havior were analyzed for more detailed descriptions of behaviors. Behaviors in- cluding courtship, aggression, and spawning were initially identified based on their similarity to those described in other serranids (e.g. Thresher 1984; Sadovy et al. 1994; Deloach 1999). The coloration of individuals was used often to dif- ferentiate among males and females and to correlate color patterns with specific behaviors. Courtship and spawning behaviors are summarized in Erisman (2003) and will only be discussed in relationship to color change. Behavioral observations were conducted at several locations on Santa Catalina Island, California. /n situ observations were made at four sites within a no-take marine reserve (Habitat Reef, Intake Pipes, Pumpernickel Cove, Blue Caverns) located in the waters adjacent to the USC Wrigley Marine Science Center, and at one site (Bird Rock) located outside the reserve boundary (Figure 1). To collect more precise data on specific behaviors and associated color patterns, 108 (50 males, 58 females) adults were captured from 20 to 23 June 2002 and placed in a 700 m? outdoor, floating net-pen located in Catalina Harbor, Santa Catalina Island, California (Figure 1). The aggregation size and sex ratio used for the captive study was based on aggregation sizes described in previous studies (e.g. Quast 1968), and from. numerous observations of aggregations conducted on SCUBA from 2000 to 2002. Captive individuals in the net pen were observed on a daily basis from 7 July to 14 August 2003, while on SCUBA or snorkeling, to document behaviors and color patterns. Results Seasonal Color Patterns Kelp bass were sexually monochromatic for much of the year. Adults and immature individuals collected and observed during the fall, winter, and spring months were generally olive green to khaki brown on their side, dorsal, and head region. This color was integrated with pale spots present throughout the body, which gave them their characteristic “‘calico’’ appearance (Figure 2c, calico phase). Variations of the calico phase were present among collected individuals, and the body color pattern of collected individuals was similar to the colors of their surroundings. Individuals inhabiting areas with dense kelp appeared much more bronze or brown, with the spots less defined and a golden chin and belly, whereas individuals inhabiting more open water habitats were dull gray or light green, with white undersides. Adult Paralabrax clathratus exhibited a pattern of seasonal sexual dichroma- tism, where most males collected and observed from May to early October had a conspicuous orange color on the snout region of their heads (Figure 2a, OS phase). However, some males did not show visible evidence of this color pattern and retained the calico phase during this period. The OS phase was not present in any females or immature individuals, and they exhibited the calico phase throughout the year. OS males were collected from May to October, and 75% of males collected from June to August showed this coloration (Figure 3). Monthly variations in the frequency of collected OS phase males were significantly dif- ferent than expected at random (Pearson chi-square goodness of fit, x? = 140.18, COLOR PATTERNS IN KELP BASS 5] 90 12 a 48 80 52 10 70 60 8 @ a. 21 Se s : o O aS 29 6 40 30 45 : 20 : 24 35 “ 10 Bs 18 0 0 | 0 0 2 0 UL JAN FEB MAR APR MAY JUN J AUG SEP OCT NOV DEC Fig. 3. Percent of OS males (bar graph) and gonosomatic index (GSI, line graph) from 365 male kelp bass (Paralabrax clathratus) collected from May 2001 to April 2002, by month of capture. Values for GSI are + | SD. Numbers represent monthly sample sizes. Data were grouped to show monthly variations Over a single year. df = 8, P < 0.01). This coloration was not observed in any individuals collected from December 2001 to April 2002. Calico phase individuals were observed at both transect sites throughout the study period (Figure 4). OS phase males were observed at both transect sites from May to July 2002, where they increased in frequency over this period (Figure 4). Monthly variations in the proportion of OS phase individuals observed on tran- sects were significantly different than expected at random for both the Intake Pipes site (Pearson chi-square goodness of fit, x? = 137.36, df = 7, P < 0.01) and the Pumpernickel Cove site (Pearson chi-square goodness of fit, y? = 173.81, df = PoP = 0.01). The estimated spawning season based on GSI and maturity data showed a pattern very similar to the monthly frequency of collected OS phase males. Mean monthly GSI of males (Figure 3) and females (Figure 5) remained low from January to April. GSI of both sexes increased from April to June, peaked in June, and steadily declined throughout the summer and fall. GSI values of males and females were lowest in February and December. Monthly variations in male GSI (Kruskal-Wallis, KW = 222.24, df = 8, P < 0.01) and female GSI (Kruskal- Wallis, KW = 214.24, df = 8, P < 0.01) were significant. Males and females containing visibly ripe gonadal tissue were collected from May to October, and over 93% of adults collected from June to August were visibly ripe. Females with hydrated ovaries were collected from June through September, and the highest frequency of hydrated females occurred in July (Figure 5). The mean GSI of females with hydrated ovaries (5.79%) was significantly higher than the mean 52 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES - INTAKE PIPES 0 Calico phase @ OS phase 42 77 112 55 159 134 133 95 100 90 80 70 60 3 50 40 30 20 10 0 DEC JAN FEB MAR APR MAY JUN JUL B PUMPERNICKEL COVE 65 1311 168 61 179 123 174 103 100 90 80 70 | 60 ss 50 40 30 20 10 0 DEC JAN FEB MAR APR MAY JUN JUL Fig. 4. Percent of calico phase and OS phase adult kelp bass (Paralabrax clathratus) from visual transects conducted at Santa Catalina Island, California from December 2001 to July 2002. A = Intake Pipes, B = Pumpernickel Cove. Numbers above bars represent monthly sample sizes. GSI of non-hydrated, ripe females (3.56%; unpaired t test, t = 7.78, df = 229, p 20:01) OS phase individuals were present throughout the day and on a daily basis in both the field observations conducted from May to early October of 2000, 2001, and 2002, and in the captive study of 2002. OS phase individuals were not ob- served in field observations conducted in late October to April, from 2000 to 2002. Because no significant difference was found in the monthly frequency of the OS phase among males collected from June to August 2001 (Pearson chi- COLOR PATTERNS IN KELP BASS 53 25 7 82 101 20 5 15 4 20 10 3 2 ie /| his. , 0 t 0 } 0 0 JAN FEB MAR APR- MAY DEC % HYDRATED FEMALES GSI (%) —_ Fig. 5. Percent of females with hydrated ovaries (bar graph) and gonosomatic index (GSI, line graph) from 397 female kelp bass (Paralabrax clathratus) collected from May 2001 to April 2002, by month of capture. Values for GSI are + | SD. Numbers represent monthly sample sizes. Data were grouped to show monthly variations over a single year. square goodness of fit, x? = 1.19, df = 2, P = 0.55), data from all males collected from during this time were pooled for further analysis. During that period, OS phase males were collected throughout the day and showed no significant differ- ences in frequency with respect to the time period captured (Pearson chi-square goodness of fit, xy? = 1.36, df = 2, p = 0.51). Moreover, the frequency of OS phase males did not differ significantly among the four primary phases of the lunar cycle (Pearson chi-square, x? = 4.45, df = 3, P = 0.22). OS phase males collected from May to October 2001 ranged in size from 165 to 386 mm SL, and calico phase males collected during that time period ranged im size from 170 to 397 mm SL (igure 6). The mean length of collected OS phase males (263.01 mm) was significantly greater than the mean length of col- lected calico phase males (247.75 mm; Mann-Whitney, U = 5455.0, df = 247, P.= 0.001). However, this result was not considered biologically significant, be- cause adult P. clathratus grow to lengths of greater than 700 mm SL (Love et al. 1996). The size range of captive OS phase males (211 to 348 mm SL) was similar to that of captive calico phase males (212 to 343 mm SL). OS phase individuals observed in the field ranged in estimated size from 200 to 500 mm SL, while calico phase individuals observed ranged in size from 100 to 500 mm SL. The latter included individuals believed to sexually immature. The OS phase was present only in ripe males, whereas the calico phase was present in both ripe and unripe males. Sixty-seven percent of ripe males collected during 2001 were OS phase and 33% were calico phase. Among males collected from May to October 2001, the GSI range of OS males (0.42% to 13.10%) were similar to that of calico phase males (0.17 to 12.94%) (Figure 7a). However, the mean GSI of OS males (5.69%) was significantly higher than that of calico phase males (2.88%) collected from May to October 2001 (Mann-Whitney, U = Seles Oprdii— 2 Se P= OO) c( Fisures7b). 54 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES Oi Calico phase MOS phase for) fo] p= i) 200 220 240 260 280 300 STANDARD LENGTH (mm) sles inl ! 160 180 320 340 360 380 Fig. 6. Size-frequency distributions of 91 calico phase and 248 OS phase male kelp bass (Par- alabrax clathratus) collected at Santa Catalina Island, California from May to October 2001. During observations conducted in the field and in the captive study, OS phase males were observed engaging in courtship and spawning behavior with gravid females while aggregated in spawning groups. However, solitary OS males outside of aggregations were also common. Calico phase individuals were observed with- in spawning aggregations and exhibited courtship behaviors typical of spawning males. These calico phase individuals also participated in spawning events. How- ever, it is not known whether these individuals were males or females in all cases. Low light levels and rapid movements of courting adults were common in field observations during the spawning period, which occurred at or beyond sunset at depths to 15 m. It was often difficult to identify the color patterns of all individuals participating in courtship behaviors and spawning rushes. The color patterns of individuals participating in courtship and spawning events were not identified for all spawning events observed in the field. Therefore, the relative proportion of OS males and calico phase males in spawning groups could not be accurately determined for field observations. Calico phase males were not observed partic- ipating in courtship and spawning events in the captive study. Ephemeral Color Patterns Instantaneous color changes and color patterns restricted to certain time periods or behaviors were documented in P. clathratus throughout the study. The calico phase was the most common body color pattern observed in the field. However, variations of the calico phase were observed when individuals moved from one habitat type to_another, and individuals would often adopt body color patterns that matched their changing surroundings. For example, individuals moving from a kelp habitat to an open water environment changed color from a green or brown color variation of the calico phase to a pale green color variation. Similar changes COLOR PATTERNS IN KELP BASS 55 14 12 A oO Sa | - O Calico phase | @ OS phase | e l } 100 150 200 250 300 350 400 450 500 STANDARD LENGTH (mm) GSI (%) = Calico phase OS phase Fig. 7. Gonosomatic Index (GSI) of 91 calico phase and 248 OS phase male kelp bass (Paralabrax clathratus) collected at Santa Catalina Island, California from May to October 2001. A = scatter plot of GSI vs SL by color morph, B = comparison of mean GSI + | SD by color morph. in body color occurred when adults that were collected for the captive study were placed in clear aquaria. However, these individuals would switch colors again minutes after placement into the captive pens and match their surroundings. These instantaneous body color changes were observed for both males and females, including OS phase males. During several observation periods, individuals involved in agonistic bouts changed colors instantaneously to a dark green or black body color with highly conspicuous white blotches covering the head and body (Figure 2e, marbled phase). The blotches were large, and they had a ““‘snowy”’ appearance that made the individual highly visible within its environment. This behavior was observed only 6 times in the field and was never observed in the captive study. Immediately following the end of the bout, individuals would re-adopt their former color pat- tern, which often matched their background. During brief aggressive interactions, often only one of the individuals would adopt this color pattern. The sex of marbled phase individuals is not known, although it was only observed for in- dividuals greater than 200 mm SL and therefore may only occur in adults. The 56 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES marbled phase was not adopted by courting males engaged in agonistic encounters with other males. Rather, courting males retained their courtship coloration, in- cluding the OS color pattern, during aggressive bouts. The marbled phase was not observed in any collected individuals. Additional color patterns were observed during spawning periods, when males and females often adopted distinct courtship colors. During courtship and spawn- ing events, OS phase males exhibited a charcoal gray color with large white spots covering the entire body. These individuals also possessed four to five black, vertical bars layered over the spots running the length of the body (Figure 2b, checkered phase). This color pattern was observed in the majority of captive males, was never observed outside of the spawning period, and was also observed in the field during spawning events. On a few occasions in the captive study, males observed during early courtship adopted this color pattern when posing or displaying to a female and then quickly changed back to a green color when courtship ceased. During the peak spawning time, however, all courting males exhibited this color pattern, although the checkered phase was not observed in any collected individuals. During courtship and spawning, females were often dark to black with white bellies and indistinct spots (Figure 2d, dark phase). This dark phase color pattern was observed both in the field and in captive individuals, but was not documented in collected individuals. On many occasions, spawning groups were identified by a dark phase, gravid female swimming rapidly, followed by several checkered phase males with bright orange snouts. Although the dark color phase was ob- served in the field and in the captive study on many occasions, not all spawning females had this color pattern. In general, the dark color phase of the female appeared to be more common under lower light conditions. During one obser- vation period in the captive study, a gravid female exhibited the dark phase for several minutes, changed body color to the calico phase for several minutes, and then reverted back to the dark phase just prior to spawning. Discussion Adult Paralabrax clathratus exhibited seasonal sexual dichromatism during the spawning season. GSI and maturity data indicate that adults began to ripen in April and May, and spawning occurred from June to September. The OS phase was present in males continuously from the late spring to early fall, regardless of time of day, day sampled, or lunar phase. OS phase males likely develop this coloration as they ripen and retain it throughout the spawning season until spawn- ing activity ceases in the fall. The striking similarity between the seasonal oc- currence of this color pattern and the spawning season, along with the fact that the OS phase was limited to ripe males, suggests that the orange snout coloration is an important component in the spawning behavior of adult kelp bass. The high GSI among OS phase males collected during the spawning season compared to the GSI of calico phase males collected during that period indicates that the OS color pattern may reflect the reproductive condition of males and may function as a signal of sexual readiness to mature females (Thresher 1984; Kodric-Brown 1998). Since males and females are monochromatic for most of the year, this color pattern may facilitate the identification of mates and the formation of spawn- COLOR PATTERNS IN KELP BASS 3) ing groups within the large aggregations which form during the spawning season (Thresher and Moyer 1983). Although the majority of male kelp bass collected and observed during the spawning season were OS phase, this color pattern was not present in all males. Upon closer inspection of collected individuals, we found that the color would often fade in newly captured individuals placed in holding tanks, over the period of several minutes. From these observations, we concluded that the lack of this color in some collected males might have been due to excessive handling time before the color pattern was recorded. It is possible that stress may have induced color changes in collected individuals, although this was never tested. Potts (1974) noted that the color patterns of the corkwing wrasse, Symphodus melops, varied under different levels of stress, and individuals often adopted a “‘fright coloring” for several days before being replaced by a more neutral color pattern. The small number of calico phase males collected and observed in the field during the spawning season could also be due to other factors. The OS color phase may be stimulated by a high density of aggregating adults. This would explain the high percentage of OS males in the captive study (92%) compared to that among collected males and individuals observed in the field. The captive study simulated a dense aggregation of breeding adults, whereas individuals col- lected and observed in the field were not always within aggregations. In the Nassau grouper, Epinephelus striatus, courtship color patterns and spawning ac- tivity are less intense in low-density populations than in large aggregations (Colin D2): Alternative mating phenotypes are common in many species characterized by sperm competition, where males must compete for mating access to females (Gross 1996; Parker 1998; Petersen and Warner 1998). ““Bourgeois males”’ (Ta- borsky 1997) gain access to females through direct monopolization of females, attractive courtship behaviors, or secondary sexual characters (e.g. color patterns). In contrast, “‘parasitic males” (Taborsky 1997) gain access to females by exploit- ing the reproductive investment of bourgeois males through sneak spawning, fe- male mimicry, and other forms of parasitic spawning (Gross 1982; Taborsky 1994; Uglem et al. 2001). Parasitic males experience higher intensity of sperm com- petition and have relatively larger gonads for their size than bourgeois males (Stockley et al. 1997; Taborsky 1998). Parasitic males also tend to be smaller than bourgeois males, because parasitic males invest considerable energy in sperm production rather than growth (Taborsky et al. 1997; Neat 2001). Paralabrax clathratus may exhibit alternative mating tactics, with OS males making an investment in attractiveness, and calico phase males increasing their potential reproductive success by mimicking females. However, the existence of an alternative mating strategy by some male kelp bass is not supported by the observed behaviors of breeding males. Aggressive interactions among males were extremely rare, and males were not excluded from mating access with females. Courtship involved several males simultaneously chasing and mobbing a gravid female, and alternative courtship behaviors were not observed. Although the mat- ing system of kelp bass was characterized by sperm competition, as shown by the high GSI among collected ripe males and group spawning behavior, the go- nadal characteristics and size distributions among male color morphs were not consistent with that of a species with alternative mating tactics. The GSI of calico 58 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES phase males were lower than OS phase males, and the two morphs had overlap- ping size distributions. In animals, carotenoid-based color patterns such as the orange snouts of male P. clathratus are usually related to physical condition and foraging abilities, since carotenoids are acquired from food and are not synthesized (Endler 1983; Kodric- Brown 1989; Badyaev and Hill 2000). Moreover, variation in male coloration often plays an important role in female choice, where brightly colored males enjoy a higher reproductive success (Kodric-Brown 1983, 1998) than their dull-colored competitors. Both OS males and calico phase individuals were observed engaging in courtship and spawning events with females, however, the relative success of the two types of males was not investigated. Differences in the intensity and percent coverage of the orange coloration on the snouts of OS males was not quantified in this observational study. Further research into the specific charac- teristics of the snout coloration is necessary to determine whether such variations are important in female choice behavior and/or the reproductive success of male kelp bass. Kelp bass spawn from 1900—2200 hrs, and the onset of spawning occurs at sunset (Erisman 2003). The high-contrast body color of male kelp bass was very noticeable during twilight, where the bright white spots became very conspicuous in low light conditions. Color patterns that contrast with a given background are believed to enhance the conspicuousness of courting males and increase the vis- ibility of male courtship behavior in some fishes (Endler 1983; Neil 1984; Kodric- Brown 1998). Similar to the orange snout coloration, the high-contrast, gray and white courtship pattern exhibited by male Paralabrax clathratus may facilitate mate recognition and enhance courtship signaling in periods of low light and near darkness. In particular, it may increase the visibility of males and allow signaling to occur over greater distances. Although generally considered diurnal fishes, P. clathratus are known to also be active at night, and their scotopic visual pigments are well adapted to low-light conditions (Hobson et al. 1981). The swollen, white abdomens and the dark coloration of gravid female kelp bass rendered them easily distinguishable from the courting males that surrounded them during spawning periods. Also, the head-up orientation of gravid females hovering in the water column may have increased the conspicuousness of their white abdomens to courting males. This type of female display behavior has been observed in several Serranus species (Clark 1965; Pressley 1981; Hastings and Petersen 1986). Similarly, Colin (1992) observed that female Epinephelus striatus with abdomens swollen with ova often adopted a conspicuous “‘white belly”’ color phase. During courtship and spawning in the coney, Epinephelus fulvus, females are identified by their white, distended bellies (Deloach 1999). Given the high levels of activity and large numbers of aggregating adults during spawning periods, such dramatic color differences among males and females may be used to coordinate the formation of spawning subgroups in some serranids, including the kelp bass. During spawning, many female Epinephelus striatus adopt a black body or “‘dark phase’’, similar to that observed in some female Paralabrax clathratus. This color is often present in females leading presumed males during courtship and spawning events (Colin 1992). The color patterns expressed by some male fishes may also assist in the deter- rence of rival males, where they act as a warning signal of aggression and social COLOR PATTERNS IN KELP BASS 59 status (Losey 1976; Neil 1984; DeMartini 1985). In the scamp, Epinephelus phen- ax, color phases are believed to reflect social status, with dominant males exhib- iting a conspicuous grey-head color. Similarly, larger males often adopt this same coloration during courtship and aggressive bouts (Gilmore and Jones 1992). Ag- gressive interactions among courting male kelp bass were rare and rarely persisted for more than 5—10 seconds. Also, the marbled phase observed during some agonistic bouts was not observed in aggressive interactions that occurred during courtship and spawning. Rather, courting males retained the checkered phase dur- ing such encounters. Therefore, male courtship coloration may be less important in deterring rival males in kelp bass. Many fishes exhibit color patterns that match their surroundings (Townsend 1929; Cott 1940). In some cases, this coloration is believed to enhance foraging by reducing their chances of being detected by prey (Hobson 1975; Moyer 1977; Endler 1983), whereas in many other fishes cryptic color patterns are believed to decrease the possibility of being detected by potential predators (Losey 1976; Endler 1978). Adult kelp bass varied significantly in body color patterns according to their habitat, generally exhibiting color patterns that made them less conspic- uous in their environments. The cryptic coloration adopted by Paralabrax clath- ratus may function in both foraging and predator avoidance. Adult P. clathratus are generalized carnivores (Quast 1968) and utilize both ambush and stalking predatory behavior strategies (Hobson 1994; Hobson and Chess 2001). Camou- flaged color patterns are likely to increase prey capture success rates by allowing individuals to get within striking distance of prey before being noticed. Similarly, these color patterns may also allow kelp bass to escape detection by larger pred- ators, including conspecifics. The bright orange snouts of breeding male P. clath- ratus made them highly conspicuous to divers in all environments. It 1s possible that OS males are at greater risk to visual predators, although this hypothesis has not been tested. The focus of our study was to describe the seasonal and ephemeral color pat- terns exhibited by adult kelp bass and the social and environmental contexts under which they occur. From our observations, it appears that many color patterns are uniquely associated with reproduction, and color patterns may play an important role in the spawning activity in Paralabrax clathratus. However, the specific functions of these color patterns can only be speculated upon until detailed ex- perimental studies of mate choice and male-male interactions are conducted. Re- search on the spectral sensitivity of P. clathratus adults, including information on their photopic visual pigments, and the spectral structure of the various color patterns are necessary to determine how each of the color patterns are perceived. The visual system of fishes is quite different than that of humans, and proposing relationships between color patterns and behaviors using the human visual system often lead to erroneous conclusions (Marshall et al. 2003). Fishes vary greatly with respect to their visual sensitivity, and it is not known whether kelp bass can distinguish between the patterns and the colors described. Of particular importance is the orange snout coloration of male kelp bass, as red-sensitive visual pigments have not been found in other reef fishes (Losey et al. 2003; Marshall et al. 2003). However, red, yellow, and orange colors are common nuptial colors in many freshwater fishes, and these colors are especially common in fishes inhabiting turbid waters (Levine and MacNichol 1979; Kodric-Brown 1998). 60 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES Acknowledgments We wish to thank M. Adreani, E. Bing-Sawyer, K. Doctor, D. Pondella, K.A. Miller, J. Froeschke, and S. Albers for their assistance throughout the course of the study. Additional assistance was provided by E. Miller, J. Cobb, D. Bottinelli, J. Lindsay, J. Brogan, K. Wisenbaker, G. Benavides, and M. Salomon. We also would like to thank the Vantuna Research Group of Occidental College and the crew of the RV Vantuna and RV Yellowfin for their assistance. We are grateful to S. Albers and the Catalina White Seabass fund for use of the grow-out facility during the captive study. Special thanks to G. Losey, P. Hastings, M. Craig, R. Carpenter, C. Lowe, and P. Edmunds for their advice and review of the manu- script. This research was supported by the USC Wrigley Institute for Environ- mental Studies, the PADI foundation (2000-18), and several funding sources at California State University, Northridge including the Nearshore Marine Fish Re- search Program (NMFRP), the Office of Graduate Research and International Programs, and the Student Projects Committee. Collections were made under Cal- ifornia Department of Fish and Game permits 803015-04 and 803038-01. This is contribution number 234 from the University of Southern California’s Wrigley Marine Science Center on Santa Catalina Island. 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Sci. 104(2), 2005, pp. 63-74 © Southern California Academy of Sciences, 2005 The Reef Fish Assemblage of the Outer Los Angeles Federal Breakwater, 2002-2003 John T. Froeschke,! Larry G. Allen,'* and Daniel J. Pondella II? 'Department of Biology, California State University, Northridge, California 91330 2Vantuna Research Group, Occidental College, Los Angeles, California 90041 Abstract.—The conspicuous and cryptic fish assemblage of the Los Angeles Fed- eral Breakwater was assessed from 2002 to 2003. Thirty-five species were ob- served or collected during the study period. The assemblage of cryptic fishes was composed primarily of a mix of Oregonian and San Diegan, species including snubnose sculpin (Orthonopias triacis), coralline sculpin (Artedius corallinus) and blackeye goby (Rhinogobiops nicholsii). The species composition of conspicuous fishes was approximately equal between taxa from these two provinces. Black- smith (Chromis punctipinnis), black perch (Embiotoca jacksoni) and kelp bass (Paralabrax clathratus) dominated the assemblage of conspicuous fishes. Species composition reflects the localized cool temperature regime of the area and the high relief kelp forest habitat. Rocky reefs are among the most important but least abundant habitats within the Southern California Bight (Cross and Allen 1993). More than 125 species of fish have been documented in this habitat, more than 25% of the Californian marine total (Quast 1968b; Feder et al. 1974; Horn and Allen 1978). Artificial reefs have been constructed within the Bight to augment natural reefs and to mitigate lost natural reefs through development or habitat degradation (Ambrose 1994). Although not their primary purpose, breakwaters form artificial reefs and have been shown to be effective fish enhancement structures in urban areas (Ste- phens et al. 1994). Breakwaters provide high relief, complex habitats that are ideal for many reef-associated fishes. The Los Angeles Federal Breakwater is 13.8 km long (McQuat 1951) making it the largest artificial reef in the Southern Cal- ifornia Bight, yet, prior to this study, a systematic characterization of the fish population on this breakwater has not been made. The breakwater at King Harbor, Redondo Beach, California has been extensively surveyed since 1974, and more than 100 species of fish have been observed with about half of those being res- ident (present year-round throughout the study) species (Stephens and Zerba 1981; Stephens et al. 1994). However, this breakwater is also characterized by a high degree of temperature stratification due to warm water input from a coastal gen- erating station into King Harbor and its proximity to the Redondo submarine canyon. King Harbor, a small craft marina, is also probably less affected than Los Angeles Harbor, a major international port, by anthropogenic effects. Quantita- tively evaluating the fish assemblage on Los Angeles Federal Breakwater will * Author to whom correspondance may be addressed: Larry.Allen@cusn.edu 63 64 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES provide critical information on the potential of these structures to replace or sup- plement natural rocky reef habitat in an urban setting. Artificial reefs have been shown to support high densities of fish due to either attraction or production of fishes, but generally have low standing stocks com- pared to natural reefs because artificial reefs are generally smaller than natural reefs (Ambrose and Swarbrick 1989; Demartini et al. 1989). Monitoring of reef fishes has become an important component of many fisheries management strat- egies to ensure maintenance of “‘healthy’’ ecosystems and sustainable fisheries (Stephens and Zerba 1981; Stephens et al. 1984; Paddack and Estes 2000). This task is especially important in areas that are near large population centers and/or are heavily influenced by anthropogenic activities. Visual censuses along transects with defined widths and lengths can be used to make reasonably accurate estimates of the density of fishes, and their effec- tiveness has been well established for fishes on temperate reefs in southern Cal- ifornia (e.g. Quast 1968a, b, c; Ebeling et al. 1980; Stephens and Zerba 1981; Larson and DeMartini 1984; Stephens et al. 1986; DeMartini et al. 1989; Allen et al. 1992). However, visual censuses tend to underestimate fish densities (Sale and Douglas 1981) especially those of small or cryptic species (Brock 1982; Bellwood and Alcala 1988). These limitations are generally well recognized and do not prevent reasonably precise density estimates for conspicuous fishes from being obtained. Cryptic fishes are usually small, camouflaged fishes that live in or among rocks, crevices, or algae. These fish usually retreat into the reef in the presence of divers and thus cannot be accurately sampled using techniques for estimating densities of conspicuous fishes. Cryptic fishes are more precisely estimated with the use of ichthyocides or anesthetics (Allen et al. 1992). Previous studies in southern California have shown cryptic fishes to be important members of rock reef hab- itats in terms of density, species richness (Allen et al. 1992), and secondary pro- ductivity (Stephens and Zerba 1981; Stephens et al. 1984). The primary goal of this study was to provide a description of the reef fish assemblage of the outer Los Angeles Federal breakwater using visual census and an anesthetic to survey both large mobile and small cryptic fishes effectively. The densities, depth distributions, biomass and seasonality of the fish assemblage were determined. Methods The Los Angeles Federal Breakwater forms the western border of the Los Angeles-Long Beach Harbor complex (Figure 1). The Breakwater was constructed in three parts. The northernmost section was completed in 1912 and the final two sections were completed in 1928 (McQuat 1951). It is constructed of quarry rock that forms a sloping high relief reef extending from the surface to 15 meters where it is bounded by a mud flat (J.T.E personal observation). During this study purple urchins (Strongylocentrotus purpuratus) forming characteristic barrens dominated the shallow subtidal portion of the reef (<< 4 m). Giant kelp (Macro- cystis pyrifera) was abundant between 5—10 m throughout the study, while cor- alline algae and macroinvertebrates dominated the deeper portions of the reef. FISH ASSEMBLAGE OF THE LOS ANGELES BREAKWATER 65 LONG BEACH WILMINGTON LONG BEACH Sampling Cryptic and conspicuous fishes were sampled quarterly from September 2002 to November 2003 at two sites along the outer Breakwater (Figure |). Fishes were not sampled in Spring 2003 due to poor visibility and severe wave action at the study site. Conspicuous fishes were censused using visual transects on SCUBA at randomly selected 6 m and 12 m isobaths. All transects were conducted be- tween 1000 and 1400 hrs. On each sampling date, divers swam a 2 m wide X 50 m long transect counting all conspicuous fishes within the 100 m? area. Counts made by two divers were averaged for each transect. All fishes that passed divers from behind were omitted to avoid counting the same fish multiple times or overestimating fishes that may be attracted to divers (Terry and Stephens 1976; Stephens and Zerba 1981; Stephens et al. 1984). Four replicate transects were conducted at each depth at two sites each sampling period, except January 2003 where two replicates per depth per site were completed due to poor visibility. Cryptic fishes were sampled in 1 m?* randomly selected quadrats using quin- aldine diluted 1:9 in 2-propanol. All fish within the I1-m quadrat were anesthetized and collected in mesh bags, fixed in 10% formalin for seven days and preserved in 70% ethanol. A minimum of four replicates per depth per site was taken during each sampling period to assess abundance and species composition. Specimens were blotted dry and weighed to the nearest 0.1 gram (wet weight; WWT) and 66 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES standard length (SL) was measured to the nearest 0.1 mm in the laboratory using digital calipers. Biomass of conspicuous fishes was estimated by determining an average length of every species from each age class and then using established length-weight regressions for each species. Cryptic species that were observed on transects were estimated by taking the mean weight of that species from cryptic collections taken during this study. The effects of depth and sampling date (season) on density and biomass were tested using two-way analysis of variance (ANOVA) with replication. Data were log (x + 1) transformed for conspicuous fishes, and log (x + 1/6 of the minimum non-zero value) transformed for cryptic fishes to restore normality and homosce- dasticity to these data. However, it is important to note that this study occurred on a single continuous reef. Therefore, depth is also confounded with changes in habitat between depths and that seasonal effects may not have been adequately sampled. These factors should be considered when interpreting these data. Results Cryptic Fishes A total of 107 individuals were collected in 62 1-m? samples. Thirteen species from eight families were collected over the study period. The assemblage of cryptic fishes consisted primarily (82.2%; Table 1) of three species, snubnose sculpin (Orthonopias triacis), coralline sculpin (Artedius corallinus) and blackeye goby (Rhinogobiops nicholsii). Snubnose sculpin was the most abundant species (37%) followed by coralline sculpin (23.4%) and blackeye goby (18.7%). Density (individuals/m?) of all cryptic fishes during the study period was 1.8 m? + 0.16 (n = 62). The density of all species combined was highest in July 2003, (Figure 2) and lowest in January 2003 although differences in density among seasons were not statistically significant (ANOVA, F; 5. = 0.59; P = 0.62). The density within the individual depth strata did not closely follow the trend of the combined depth strata. The highest density was recorded in shallow stratum in July 2003, the lowest density in October 2002, and intermediate density in November 2003. Overall, mean density was higher in the shallow stratum but was not significant (ANOVA, F,,, = 0.8; P = 0.37). The shallow stratum was not sampled in January 2003 due to strong surge, which prevented accurate sur- veys at shallow depths. The fish density peaked in the deep stratum in October 2002 and November 2003, with the lowest density encountered in January 2003. The number of species remained relatively constant over the sample period, rang- ing from a low of five in January of 2003 to a maximum of seven in October 2002 and July 2003. Mean biomass (gWWT/m~/) of all cryptic fishes during the study period was 3.3 + 0.82 (n = 62; Figure 3). Biomass closely paralleled the trend of density. It was highest in July and November of 2003 and lowest in January 2003 and there was no significant difference in biomass density between depths (ANOVA, F, 46 = 1.7; P = 0.20) or among seasons (ANOVA, F, 4, = 0.1; P = 0.94). Black- eye goby constituted the most biomass, comprising 18.7% of the total, although this species was ranked fourth in terms of numerical density (Table 1). Painted greenling (Oxylebius pictus) was ranked second in terms of biomass comprising 67 FISH ASSEMBLAGE OF THE LOS ANGELES BREAKWATER SI 9 Ik 4 fe sarsads Jo Jaquinyy CI) (Tp) (8°¢) (CT) (8°7) (-W/ LAA MS) Ssseworg 1 81 Lc GI 81 -wy'ou AyIsuoqd (¢°SLE) LOT 8C VE Ol CE [BIOL (8't) 60 (y'6) I (v6) I ysyyoor taydoy SNIDUADI SaJSDGaS CAS) 650 (7p) (CSD YySUyoor UMOIG SNIDINILUND Sayspgas (V1) 60 I CLG) | ysyyoor djay SUIMIAOAJD SAISDGAS (6'6) 6'0 (9°61) I (9°61) I YSyUoIdioos eIUIOFITED pIvYNS Yuavd1oIs (£0) 60 (CO) I Gorn AqoS v1qd7 DAGAz SNUdKAYIAT (TO) 60 (70) I (0) I YUIsyorylg smuidyound snuosy) (Dot G (Cre) Z SUI[UIDIS PoyUIed snjoid snigajAxQ G2) 3'C € (LY) € YSYSUI[O eIUIOFITeD UOPOSSaYA XOSAIGOH) (VE) ST (89) € CEISIEG (OI) I ysydjay purys] Maploy snulI0]]V QOL) LY (EGIDEG CLIDKC (Ops ysydjay ponods SsuDsa]a DISUOGGIDH VAS LS (OLE) OT COO) KOnO) al (6'0) I (GSD ul Aqos akayori gq usjoyoiu sdoigosoulyy CAD) ASE (C97) ST (RADE (£°C) 6 (Or € (Cp) v UId]Nds aUTTeAIOD SNUI]JDIOI SNIPAAW (OLD) LOr LIS) (ei (LOI) 8 (x) 91 (Se (9'L) TI uldjnos asouqnus siop14] spidouoysscQ W [R1OL CQOT JaquIsAON cooc Aine cgoc Arenue¢ ZOOT 19q01909 auIeU UOWIUWIOD sotoads ‘sosoujuored Ul payeoIpul (-W/L AAAS) SSPULOIG “CQOT 1240190 0} TOOT 19q0}IQ WOLF ToMYRIIG [eIOPsJ SoPoOsUY SOT JajNO ay} Ie soysy dNdAID Jo SADAINS ApIoweNb dAY UL PadaTJOO syenprArpul JO sseuloIq pue AyISUdq “| IIGRL 68 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES Density of Cryptic Fishes Density/m? October 2002 January 2003 July 2003 November 2003 Fig. 2. Mean density of cryptic fishes at six and twelve meter depth strata at the Los Angeles Federal Breakwater. Density varied significantly by season in the six meter stratum (ANOVA F,,, = 17.45, P < 0.001) although seasonal variation in the deep stratum was not significant (ANOVA BF, ;, = 1.11; P = 0.36). 17.3% of the total (Table 1) although only two large individuals were collected during the study. Snubnose sculpin was numerically dominant but third most abundant in biomass (17.0%). Three species of juvenile rockfish, kelp rockfish, brown rockfish and gopher rockfish (Sebastes atrovirens, S. auriculatus and S. carnatus respectively) contributed disproportionately to the biomass total contrib- uting 9.8% of the total biomass although only three large individuals were col- lected. Six families accounted for 97.4% of the total biomass and were dominated Biomass of Fishes ” =) S a 30 ™ Cryptic Fishes = * DConspicuous Fishes S25 ge E = 20 ae = 215 Eg B § 10 yo a 5 te ro 5 October 2002 January 2003 July 2003 November 2003 Fig. 3. Biomass density of cryptic and conspicuous fishes for two depth strata combined, by season, Over the period of October 2002 to November 2003. There was no significant difference in biomass of cryptic fishes between depths (ANOVA F, ,, = 1.4; P = 0.24) or among seasons (ANOVA F, 4, = 0.3; P = 0.76). A significant peak in biomass density of conspicuous fishes occurred in July 2003 (ANOVA, F; 5, = 18.8; P < 0.001; Tukey post hoc test; P < 0.001). Results shown as mean + SE. FISH ASSEMBLAGE OF THE LOS ANGELES BREAKWATER 69 by Cottidae (30.4%), Scorpaenidae (19.7%), Gobiidae (18.9%), Hexagrammidae (17.3%), Clinidae (7.6%) and Labrisomidae (3.4%). Conspicuous Fishes Twenty-eight species from 13 families were observed on 56 transects during the study period (Table 2). Five species accounted for 80.8% of all fishes counted on visual transects during the study. These included blacksmith (Chromis punc- tipinnis; 56%), black perch (Embiotoca jacksoni; 12%), pile perch (Rhacochilus vacca; 6%), kelp bass (Paralabrax clathratus; 3.5%) and senorita (Oxyjulis cal- ifornica; 3.3%). Large schools of blacksmith juveniles were often observed. The density of the top five species remained relatively constant during the study. The mean density of conspicuous fishes was 85.3 + 7.1/100 m? (n = 56). Patterns of density were similar between the depth strata except in October 2002 when juvenile blacksmith recruited in large numbers (Figure 4). Fishes were sig- nificantly more abundant in shallow depths throughout the study period (ANOVA, Fy 4g = 21.4; P < 0.001). Density also varied significantly by season in the shallow stratum (ANOVA, F;,5, = 17.45; P < 0.001) and was significantly higher in July 2003 (Tukey post hoc test; P < 0.05). The peak density in the shallow stratum during summer was primarily due to the abundance of juvenile blacksmith that recruited during that period. Variation in density at the deep strata over time was marginally significant (ANOVA, F;,, = 2.72; P = 0.07; Figure 4). Abundance in the deep stratum showed a similar pattern of seasonal variation, despite the ab- sence of the juvenile blacksmith. Mean biomass (Kg/100 m7) of all conspicuous fishes during the study period was 12.1 + 1.16 (n = 56; Figure 3) and closely followed the pattern of density. Biomass was significantly higher in the shallow stratum (ANOVA, F, 5, = 7.5; P = 0.008), and a significant peak in biomass density occurred in July 2003 (ANOVA, F352 = 18.8; P < 0.001; Tukey post hoc test; P < 0.001). The density Gindividuals/100 m/’) of cryptic fishes contributed substantially to the overall density of cryptic and conspicuous fishes. The mean density of cryptic fishes combined across depths was 174 + 21.7 (n = 62) compared to 85 + 7.1 (n = 56) for conspicuous fishes increasing the total density of fishes 300% and constituting 67% of the total density. Six species were observed both on visual transects and in cryptic collections (Table 3), Species richness was increased from 28 to 35 species (an increase of 25%) with the inclusion of cryptic fishes; however the increase in biomass was minimal (< 10%), Discussion Species richness of cryptic fishes from the Los Angeles Breakwater was com- parable to that found in other studies of rocky reef habitats. In this study, 13 species of cryptic fishes were collected in 62 benthic samples. This is comparable to 12 species in 60 samples at King Harbor (Stephens and Zerba 1981), nine species in 20 samples at Palos Verdes (Stephens et al. 1984) and 14 species in 105 samples using rotenone enclosures at Santa Catalina, Island, California (Allen et al. 1992). In comparison, 28 species were observed during 56 visual transects at the Los Angeles Breakwater during the same period. A mean of 9.6 + 0.31 (n = 56) species per transect were observed, similar to the 7-12 species per 100 m7? transect reported by Stephens et al. (1994) at King Harbor, California. SOUTHERN CALIFORNIA ACADEMY OF SCIENCES 70 00 + 00 00 + 00 00 + 00 00 + 00 00 + 0'0 10 + 10 00 + LO 00 + 10 TO + £0 c0 + 90 00 + 70 c0O + 90 TO + LO 00 + 90 60+ SI £0 + 80 LO + 60 LO+ cl CO+ I'l 00+ eT TO+ €1 t+ 81 CO+ VC HON Le GW Lic FO) Li CO + 86 8c + OSL [RIOL = uv sv pojuosoid ose si[NsoY “EQOT JOQUISAON 0} ZOYOT 19qQ019Q WoOIJ s}OasuR [PNSIA 9¢ UO PdddAINS (-W QO]) Seysy snonordsuos jo Aysueg 10+ 10 Foss -10 +| N a VT N Soe aS aril sell ell sell Se Go ct (Ch) SQN CO Garam GNCO GN Soo oo oo Se agit Gell Sell Sell sell sell sell “all el ONDMOTFUO DTA T = Soo sao 2S S&S ri CO co © acl ae) Sell Sell oe) COONS Or Si cor Wa 61 16 €OOT IOQUIDAON . N AN ctl +| BOLeenO CO 80) On C0 60: 2b One 6i0 6s 20 LO = SO CO = Ol 0) S510) vO = Cll (SX) 2S IFC ileaeae <6 0) ze FOERr | ere nen lta One= OIG Oi0s= Sal loz? 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S1NLAXE SNIDAYIVDIJI XDAGVDIDAD| DIIDA SNPIYIOMYY 1UOSYIVI DIOIOIQUA stuuidyound s1uo1y) saroeds oepiuardi09¢g depHnuopolajay oeprusedi09¢g aepmog oeprusordiodsg adeplooOIqUIA, Ieprlulosliqe’] oeplynuary Sep deploojoIquiq sepiiqoy sepluardioss seploojoiquiq sepiqe’y oepruaedi09sg ovpisoydAy aepLnUdOeWIOd epluR.LIaS avpisoydAy SPPILULUPLISeXOH aepliqe ] aepisoydAy aeploojoIquiq oepLiqr’] IEPIUR.LIIS aeploojoIquiq aseprloojoiquiq depLNUDIeUIOd ATTuue 4 ‘IOLIa prepur}s eAlAaL FISH ASSEMBLAGE OF THE LOS ANGELES BREAKWATER | Density of Conspicuous Fishes 200 Mi2m —_ ao S&S) Density/100m? S S Oo oO October 2002 January 2003 July 2003 November 2003 Fig. 4. Density of conspicuous fishes at six and twelve meter depth strata. Density varied signif- icantly by season 6m ANOVA F,,,; = 17.45, P < 0.001. Variation in density at the deep strata was not significant. Results shown as mean + SE. Density varied seasonally in a similar manner with both the cryptic and con- spicuous fishes at the Federal Breakwater. The density of both conspicuous and cryptic fishes peaked during the summer of 2003 corresponding to the warmest period of the study. The density of the five most abundant conspicuous species were relatively constant throughout the study suggesting that these species are all permanent residents of the reef. Blacksmith is a warm temperate species that has been the dominant planktivore in most southern rocky reef kelp bed environments since 1976—1977 when sea surface temperatures in southern California began to increase (Stephens and Zerba 1981). This species depends on high relief reef for shelter during nocturnal periods and is well suited to breakwaters because of the high availability of caves and crevices used at night. Six species of surfperches (Embiotocidae) were observed during this study and comprised 21% of all fishes counted. After the blacksmith, the black and pile perch were the most abundant fishes. These surfperches are unique in that they are non-dispersing livebearers who are dependent upon the resources of the reef they inhabit making them excellent models for examining reef productivity (El- lison et al. 1979; Schmitt and Holbrook 1990; Pondella et al. 2002). As such, annual year-class strength of newborn surfperches was tightly coupled to habitat productivity in Santa Barbara, California (Holbrook et al. 1997). Abundance of black and pile perch were higher than reported at King Harbor and much higher than the density at Palos Verdes, Rancho Palos Verdes, California, the nearest rocky reef (Pondella et al. 2002). The relatively high density of these demersal surfperches was an indication of overall reef production and health. Overall, few differences were apparent in the distribution of fishes between the Shallow and deep strata. The shallow portions of the breakwater had higher den- sities of conspicuous fishes that were largely driven by the presence of juvenile blacksmith. No trend in densities of cryptic fishes with depth was observed. How- ever, cryptic fishes were extremely rare in the urchin barrens that dominated the shallow regions of the reef (J.T-E pers. observ.). Two species of sculpins (Cotti- dae) collected in the study were more abundant in areas with fleshy red algae or areas protected from physical disturbance. Exposed areas and areas dominated F2 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES with coralline algae often had few or no cryptic fish present. It appears that wave action may prevent cryptic fishes from inhabiting the most exposed habitats when appropriate shelter is absent. Fishes collected in cryptic samples consisted of both small camouflaged forms and juvenile benthic fishes including three species of rockfishes and the painted greenling. The small cryptic fishes consisted primarily of three species, which contributed 82% of the total individuals and 49% of the biomass. Overall, cryptic fishes increased the total numerical density estimate of the reef by 300% while their contributions to total biomass are less than ten percent. However, these fishes have a high turnover rate and may serve as important prey items to other fishes constituting an important component of energy transfer in reef ecosystems. Many studies have attempted to discern the factors that influence fish assem- blages in particular habitats. Artificial reefs in particular received a great deal of attention because they are often used as mitigation tools to replace lost habitat. In order to mitigate lost habitat effectively they must replace natural reefs in terms of species composition and biomass. Most studies comparing artificial and natural reefs have found general similarity in the fish assemblages (Russel 1975; Jones and Thompson 1978; Molles 1978; Matthews 1985). Studies have also reported higher densities of fish on artificial reefs than on natural reefs (Ambrose and Swarbrick 1989; Pondella et al. 2002). Some characteristics that influence tem- perate fish assemblages include temperature regime, recruitment success (Stephens et al. 1994) and algal cover (Holbrook et al. 1990). Stephens et al. (1984) sug- gested that temperature change is the most important factor controlling changes in the kelp-rock fish assemblage. Over the past three decades the Southern Cali- fornia Bight has warmed appreciably and Oregonian species have declined in this region. However, on a localized scale a persistent influence of cool water can support these species, a process that has been noted on the Pacific coast of Baja California (Horn and Allen 1978; Pondella et al. 2005). The Los Angeles Federal Breakwater supports a diverse and abundant reef fish assemblage. Species richness and density were at or above comparable artificial and natural reefs. The persistent cool water of this area influences these factors. The largest artificial reef in Southern California, which borders the third busiest commercial port in the world, supports a healthy and robust ichthyofauna. Acknowledgments We thank the graduate students of the Nearshore Marine Fish Research Program that made this study possible. We are grateful to the Aquarium of the Pacific and the California State University office of graduate studies that provided funding for this project. We would also like to thank the Port of Los Angeles and espe- cially Ralph Appy for support of this research program. Literature Cited Allen, L. G., Bouvier, L. S. and Jensen, R. E. 1992. Abundance, diversity and seasonality of cryptic fishes and their contribution to a temperate reef fish assemblage off Santa Catalina Island, California. Bull. So. Calif. Acad. Sci., 91(2): 55-69. Ambrose, R. E and Swarbrick, S. L. 1989. Comparison of fish assmeblages on artificial and natural reefs off the coast of southern California. Bull. Mar. Sci., 44(2): 718-733. Ambrose, R. FE 1994. Mitigating the effects of a coastal plant on a kelp forest community: rationale and requirements for an artificial reef. Bull. Mar. Sci., 55:694—708. FISH ASSEMBLAGE OF THE LOS ANGELES BREAKWATER 73 Bellewood D. R. and A. C. Alcala. 1988. The effect of minimum length specification on visual estimates of density and biomass on coral reef fishes. Coral Reefs, 7:23—27. Brock, R. E. 1982. A critique of the visual census method for assessing coral reef fish populations. Bull. Mar. Sci., 32:269—276. Cross, J. N. and L. G. Allen. 1993. Fishes. Pp 459-540 in Ecology of the Southern California Bight (M. D. 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Fish., 6(1):111-—121. 74 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES Stephens, J. S. Jr, P A. Morris, K. E. Zerba and M. S. Love. 1984. Factors affecting fish diversity on a temperate reef II: the fish assemblage of Palos Verdes Point, 1974-1981. Env. Biol. Fish., fdi25 9-273: Stephens, J. S., Jr, G. A. Jordan, P. A. Morris, M. Singer and G. E. McGowen 1986. Can we relate larval fish abundance to recruitment or population stability: a preliminary analysis of recruit- ment to a temperate rocky reef. CalCOFI Rep., 27:65-—83. Stephens, J. S., Jr, P. A. Morris, D. J. Pondella, T. A. Koonce and G. A Jordan. 1994. Overview of the dynamics of an urban artificial reef fish assemblage at King Harbor, California, USA, 1974— 1991: A recruitment driven system. Bull. Mar. Sci., 55(2—3): 1224-1239. Terry, C., and J. S. Stephens, Jr. 1976. A study of the orientation of selected embiotocid fish to depth and shifting seasonal vertical temperature gradients. Bull. So. Cal. Acad. Sci., 75:170—183. Accepted for publication 22 December 2004. Bull. Southern California Acad. Sci. 104(2), 2005, pp. 75-99 © Southern California Academy of Sciences, 2005 Structure and Composition of the Polychaete Community from Bahia San Quintin, Pacific Coast of Baja California, Mexico Victoria Diaz-Castanfieda,'!* A. de Le6n Gonzalez,” and E. Solana Arellano! 'Departamento de Ecologia, CICESE, Km 107 Carr. Tijuana-Ensenada, Ap. Postal 2732, Ensenada, Baja California *Laboratorio de Biosistemdtica, Facultad Ciencias Biolégicas, UANL San Nicolas de Los Garza, Nuevo Leon C. P. 66451 Mexico Abstract.—The diversity patterns of the polychaete fauna from a Pacific coastal lagoon were described. Polychaetes were collected in 1995 and 1998. This lagoon is formed by 2 arms: the western arm named Bahia Falsa and the eastern arm named Bahia San Quintin. 46 stations were sampled with a geological box corer. A total of 3,275 polychaetes, 28 families, 56 genera, and 104 species were iden- tified in 1995, and 3,168 polychaetes were collected in 1998, 21 families, 39 genera and 65 species. From all the macrofauna collected in both surveys, poly- chaetes represented 45.2%. From the species collected, 55% correspond to new records for the area. Families Dorvilleidae, Polynoidae, Oweniidae, Scalibreg- matidae, Sternapsidae and Sigalionidae present in 1995, were not in 1998 survey. The stations with higher abundances (> 100 specimens/0.02 m?) were located on the southern half of Bahia San Quintin. Species richness and diversity were also higher in San Quintin Bay. From the 30 families previously reported for San Quintin lagoon, 23 have been collected and 6 families were added: Ampharetidae, Oweniidae, Scalibregmatidae, Sternapsidae, Dorvilleidae and Sigalionidae. Fam- ilies not found in both surveys were: Paraonidae, Magelonidae, Apistobranchidae, Sphaerodoridae, Trichobranchidae, Chrysopetalidae and Arenicolidae. Results showed slightly lower redox potential values (—336 to +187 mV), slightly higher sediment temperatures (19.8°—22.1°C) and organic matter contents (0.3—4.1%) in 1998. From 1995 to 1998 a change in the composition and structure of the polychaete communities was noted; species richness diminished from 104 to 65 species. The trophic complexity changed with an increase of deposit-feeders, the abundance of other trophic categories decreased, indicating a loss of complexity. Significant changes in the abundance of some families were detected, some increased their abundances: Spionidae from 17% to 48%, Orbintidae from 4% to 13%; other families decreased in terms of abundance and number of species: Lumbrinereidae from 11% to 1.4%, Nereididae from 9% to 1% and Sabellidae from 14% to 5%. These modifications altered the composition and structure of the polychaete com- munities in this lagoon. Increased anthropogenic disturbance (oyster culture, ag- riculture) and environmental variability due to the ENSO 97-98 may have af- fected recruitment and survival of some polychaete species. * Corresponding author. E-mail: vidiaz@cicese.mx 1S 76 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES Introduction Some lagoons, located along the Pacific coast of Mexico, present ideal hydro- logical and sedimentary characteristics which make them potential sites for aqua- culture. The San Quintin complex is one of these coastal lagoons that favor the development of bivalve aquaculture. It 1s considered ecologically important be- cause if is a nursery area for several fish species, a resting site for migrating birds which have lost most of their resting and feeding areas in the United States, and its high productivity and diversity, in part due to upwellings which supply nutri- ents periodically. It is environmentally important to obtain baseline scientific data that help understand how benthic communities function and how they change during different climatological conditions. The hydrology of San Quintin lagoon has been studied (Alvarez-Borrego & Chee-Barragan 1976; Alvarez-Borrego et al. 1975; del Valle & Cabrera-Muro 1981 a, b; Farfan & Alvarez-Borrego 1983). In contrast, there is a lack of infor- mation on macrofauna. One of the most neglected, major groups of marine in- vertebrates may be the polychaetous annelids that could be useful as indicators of varying degrees of marine pollution (Tsutsumi 1990; Pocklington & Wells 1992). Only three polychaete surveys were found on the literature: Reish (1963) 90 stations sampled in 1960 in Bahia San Quintin (BSQ eastern arm), Calder6n- Aguilera & Jorajuria-Corbo (1986) I1 stations sampled in 1981-82, 8 in BSQ and 3 in Bahia Falsa (BF western arm); and Diaz-Castaneda & Rodriguez Vil- lanueva (1998) 39 stations sampled in December 1992, 13 in BF and 26 in BSQ. Coastal marine benthic communities are threatened by human activities, and the present rate of habitat degradation is alarming. Given that only a small fraction of the benthic organisms that reside on or are buried in sediments have been described, it is likely that species are being lost without ecologists knowing they existed (Snelgrove 1999). Polychaetes constitute an important macrofaunal group in this lagoon comprising about 70% of the benthic biomass and individuals (Barnard 1970; Calder6n-Aguilera & Jorajuria-Corbo 1986). More than 1,450 polychaete species are known from Mexico (Salazar-Vallejo et al. 1989; Diaz- Castaneda & Rodriguez-Villanueva 1998). Polychaetes are a significant compo- nent of all marine ecosysytems, they dominate soft-bottoms communities in terms of numbers of species and individuals. These annelid worms are important in food webs and in energy transference, both as predators and as important prey items for other animals, including crustaceans, fish and wading birds (Knox 1960). They present different feeding modes (carnivores, herbivores, omnivores, deposit-feed- ers, symbiotic chemoautotrophic bacteria), this plasticity could be the reason of their success in many environments (Beesley et al. 2000). Many species are im- portant bioturbators of sediment and facilitate the incorporation of organic matter into sediments. Polychaetes show a spectacular diversity of reproductive and de- velopmental modes which allow them to live in different environments (Wilson 1991; Giangrande 1997). Because of their cosmopolitan distribution, polychaetes can be used as indicators of pollution and the “state of health’ of a benthic community (Pearson & Rosenberg 1978; Reish 1980; Bellan et al. 1988; Pock- lington & Wells 1992; Lardicci & Rossi 1998). From a management perspective, they are useful organisms for identifying problem sites and for the assessment of the severity of the problem. They respond POLYCHAETES FROM THE PACIFIC COAST OF BAJA CALIFORNIA a7 to disturbance induced by different kinds of pollution, by exhibiting quantitative changes in assemblage distribution. Polychaetes can also be used as indicators of recovery of benthic environments from perturbations since in many cases they are major elements of the recolonization process (Diaz-Castaneda et al. 1989; Diaz-Castaneda & Almeda-Jauregui 1999). In spite of their importance in benthic communities few faunal studies have occurred in Mexico, in part because of identification problems due to lack of proper identification keys as well as the low number of polychaetologists (Salazar- Vallejo et al. 1989; Pocklington & Wells 1992). El] Nino is an important phenomenon throughout the world. Its effects on ma- rine ecosysytems and organisms may go beyond temperature change. Invertebrates have complex life cycles in which certain life stages, and therefore the dynamics of entire populations, are at the mercy of various physical processes acting within the ocean-atmosphere system (Arntz & Tarazona 1990; Bakun 1996; Escribano et al. 2004). During El Nino Southern Oscillation (ENSO) 1997-1998, high tem- peratures and low nutrient concentrations resulted in widespread mortality of giant kelp forests (Macrocystis pyrifera) (Tegner & Dayton 1987) and other marine organisms in the region. Temperature anomalies greater than 1°C persisted con- tinuously for 8 months in the west coast of Baja California, in some cases anom- alies attained +3°C (Dayton et al. 1992). The purpose of this study is to describe the composition and structure of poly- chaete communities in San Quintin lagoon in 1995 and 1998 before and after the El Nino 1997-98. Study Area San Quintin complex is a slightly hypersaline, highly productive coastal lagoon located between 30°24’—30°30’ N and 115°57’-116°O1' W in the Pacific coast of Baja California (Fig. 1). This lagoon has an area of 42 Km/? (4,200 hectares) and around 80% of it 1s covered by the eelgrass Zostera marina (Inclan-Rivadeneyra & Acosta-Ruiz 1988; Poumian-Tapia & Ibarra-Obando 1999). It has been ex- ploited for many years (mariculture) but it can still be considered a relatively non disturbed area, although oyster culture is increasing. The region is arid, with a mean annual rainfall of about 150 mm. About 90 percent of the rainfall occurs between October and March. Seagrass beds are important nursery areas for many species of fish and inver- tebrates, including several of economic importance (Stoner 1980 a, b; Orth & van Montfrans 1984, 1990). They also help to stabilize sediments thus reducing coastal erosion and are responsible for the composition and diversity of the seagrass infauna. The lagoon has the shape of an inverted ““Y’’, it consists of two sub-basins: BF (west) and BSQ (east). BF has an average depth of 4 m whereas BSQ has an average depth of 8 m. The bay has extensive intertidal and shallow subtidal shoals and channels up to about 10 m deep extending along the length of each basin. It has a permanent entrance and exchanges water with the coastal ocean. During low tides around 20% of the seafloor is exposed. An important aspect of the marine environment is the pattern of coastal upwelling, which is strongest between May and August (Aguirre-Munoz et al. 1999). The granulometric studies show that in shallow areas as well as to the north of both arms clay and silty-sand 78 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES 116° 00° W 30°307N A e 1 2 3 4, Molino Viejo Kenton Hill Bahia @22 San Quintin a4 Mt. Ceniza 8o 236 30° 25'N Pta. Azufre Mt. Mazo 0 500 1000 EE | METROS 116° 00° W 115° 55° Fig. 1. Location of San Quintin lagoon on the Pacific coast of Baja California and sampling stations. predominate, whereas near the mouth very fine sands are more abundant. The channel sediments are highly diverse, going from medium to fine sand and silt (Calderon-Aguilera 1992; Camacho-Ibar et al. 1997; Poumian-Tapia & Ibarra- Obando 1999). The lagoon margins present a typical saltmarsh flora with Spartina foliosa and Salicornia virginica and other vascular plants (Dawson 1962; Barnard 1970). Material and Methods Forty six stations were sampled in December 1995 and April 1998, including [5 stations in BF and 31 in BSQ (Fig. 1). Samples were collected using a box corer (16 cm internal diameter, 13 cm depth, sampling area of 0.02 m7). Tem- perature and redox potential were measured immediately after collection of each POLYCHAETES FROM THE PACIFIC COAST OF BAJA CALIFORNIA 79 sample by probing 2—3 cm inside the sediments an electrode coupled to a field potentiometer and a thermometer. Sediments were sieved in the field using a 1.0 mm mesh size and retained material was fixed in 10% buffered formaldehyde. In the laboratory, samples were washed and transferred to 70% isopropanol. Differ- ent zoological groups and particularly polychaetes were then sorted and identified at species level whenever possible. Organic matter (percent of dry weight) was evaluated by ignition loss (Byers et al. 1978). Statistical methods were used to describe the structure and organi- zation of the polychaete communities within the bay. Shannon diversity index and Pielou equitability were calculated in order to study the structure and degree of organization of the communities (Shannon & Weaver 1963; Frontier 1985; Pielou 1977). Trophic groups were determined using Fauchald & Jumars (1979) and Rouse & Pleijel (2001). Olmstead and Tukey’s test (Sokal & Rohlf 1995) was applied to analyze spatial distribution of polychaetes. This technique plots the frequency of appearance in each site sampled expressed as percentage against the density of organisms for each species. A mean average was calculated for both axes, resulting in four quadrants: I Frequent and abundant species, If Non frequent and abundant species, III Non frequent and non abundant species and IV Frequent and non abundant species. Stress predictability (Alcolado 1992) modeling was applied to establish the level of environmental stress existing in the bay. Environmental severity or stress was predicted based on values of diversity (H’) and evenness (J’), coupled with redox potential values. Ordination and classification methods were used to detect spatial patterns among the polychaete fauna. The relationship between sample stations 1s reflected by the position they display in factorial space; when the two stations were close to each other, they had more similar faunistic profiles (Frontier & Pichod-Viale 1993; Diaz-Castaneda et al. 1993). A factorial correspondence analysis was car- ried out on the faunistic data: abundance of species and 46 stations. Cluster anal- ysis using Pearson and Bray-Curtis coefficients (Bray & Curtis 1957; Sokal & Rohlf 1995) was employed to evaluate the level of association of different stations and species. A non-metric multidimensional scaling (MDS) method was used for the,community ordination (Program PRIMER 5.1.1 for windows) since this tech- nique has demonstrated to be suitable for multiple ecological purposes (Clarke 1993; Clarke & Green 1988). The MDS is based on the calculation of similarity/ dissimilarity coefficients among samples, in this case, the similarity coefficient of Bray-Curtis. One data matrix was created for each sampling period using abun- dance per species. Data were treated using Primer Program 5.1.1 for windows and Statistica v. 5.0, after transformation to log,) (X + 1) as suggested by Frontier (1983) and Legendre & Legendre (1984). Results In 1995, the redox potential values (Eh) were negative in most of the stations. In the eastern arm they varied between —340 and +162 mV; BF presented values between — 320 to +161 mV. Sediment temperatures oscillated between 19.1 and 22.0°C. Organic matter values varied between 0.3 to 3.4% in BSQ and 0.1 to 3.1% in BE In 1998 only 43% of stations were measured for Eh and temperature. 80 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES Table 1. Physico-chemical values of San Quintin lagoon sediments. 1995 1998 Station Eh(mV) gel % O.M. Eh(mV) Le % O.M. 2 3.40 3 —340 2S 2.03 330 20.2 4.05 4 [55 ZAG 1.68 —208 Died 2.90 5) —106 AV) 2.84 i how 20.9 1.86 =a 7S 21.4 2.04 8 196 20.8 1.38 =180 2126 t35 9 —245 20.8 2.01 = Pis\8) 20.9 2.14 10 130 DD DNS) 1] 73 Pa) AO) 1.10 12 = NOY AVS) 1:03 —98 20.8 1.66 13 =a) 20.2 0.84 14 = DAO ey —144 DAE 1.48 16 hs WS) 2S 17 — 67 20.0 183 18 NOS. 20.1 2.04 AWAY) 21.4 2.40 19 INS} 20.6 DD 21 cal wih [oJ )S) —174 PALS) je=)/ Di) = 82 HOR 150 =o 21.4 192 24 162 PAT 2.46 DS lt Zs 27) = 126 GA A) 1.94 26 95 PING) 0.80 28 (G2 DOES 1.38 103 Pa M5) 1.45 29 66 Di slesik O91 30 —43 Dee 0.30 154 19.8 0.50 3 09 Des 0.42 32 Sy 21.4 1.30 33 16] DAY, 0.22 187 BNNs) 0.55 34 —24 DAs 2.14 3)5) 128 Dav 2.45 36 05) 2ASG 1.60 — 106 21.8 1.66 38 123 2A6 250 = Is DAES 1.87 a9 =136 PNP? DAS 40 —49 4] 33 PEWS) 2290 = 9 20.9 ZO 42 = 176 DAs) 44 =320 DED BA ee Th) 21.8 295 45 808 2a 4.11 46 29 21.4 3.30 In the eastern arm the Eh varied between —336 mV and +154, while the western arm presented values between — 308 and +187 mV. Sediment temperatures were in the range 19.8 to 22.1°C, while the organic matter content ranged between 0.5 to 4.0% in BSQ and 0.3 to 4.1% in BF (Table 1). These results show slightly lower Eh values and slightly higher temperature and organic matter contents in L998: : The lists of species found in each survey are given in Table 2. In 1995, a total of 8,680 benthic organisms were collected, of which 38% were polychaetes, 36.5% were crustaceans and 27.4% were molluscs. The 3,275 polychaetes col- POLYCHAETES FROM THE PACIFIC COAST OF BAJA CALIFORNIA 8] lected and identified belonged to 28 families, 56 genera and 104 species (Table 2: The families best represented were Capitellidae (19%), Spionidae (17%), Sa- bellidae (14%), Lumbrinereidae (11%), Nereididae (9%), Cossuridae (8%) and Syllidae (8%). The 10 top dominant species were Prionospio heterobranchia (331), Chone infundiliformis (295), Mediomastus californiensis (264), Cossura candida (236), Scoletoma crassidentata (222), Exogone lourei (206), Capitella capitata (147), Armandia brevis (130), Neanthes arenaceodentata (121), Chone mollis (117). The first eight species constitute 55% of the total abundance, the first five have been reported as abundant in previous studies (Reish 1963; Cald- erOn-Aguilera 1986; Diaz-Castaneda & Rodriguez-Villanueva 1998). Reish (1963) found six species that constituted the dominant bay species on the basis of number of specimens. These were, in decreasing order of importance, Prionospio malm- greni, Exogone verugera, Cossura candida, Capitia ambiseta, Scoloplos acmeceps and Fabricia limnicola. Calder6n-Aguilera (1992) reported five numerically dom- inant species: Exogone occidentalis, Pseudipolydora kempi, Scoloplos acmeceps, Prionospio heterobranchia and Neanthes arenaceodentata. In April 1998, a total of 5,584 benthic organisms were collected, of which 56.7% were polychaetes, 27.2% were crustaceans and 7.5% were molluscs. The 3,168 polychaetes identified, belonged to 21 families, 39 genera and 65 species (Table 2). The families best represented were Spionidae (47.6%), Capitellidae (12.3%), Syllidae (10.5%), Paraonidae (7%) and Orbiniidae (6.8%). The first six species constitute around 75% of the total abundance. The ten top dominant spe- cies were Prionospio heterobranchia (832 specimens), Polydora websteri (548), Scoloplos acmeceps (370), Exogone lourei (291), Mediomastus californiensis (273), Cirriformia spirabrancha (128), Capitella capitata (68), Chone mollis (62), Megalomma pigmentum (59) and Fabricinuda limnicola (50). The following families present in 1995 were not found in the 1998 survey: Dorvilleidae, Polynoidae, Owentdae, Scalibregmatidae, Sternapsidae and Siga- lionidae. Some of these families have species that are carnivorous. The increase in temperature in 1998 is related to a diminution of prey items which in turn may have affected their abundances. Olmstead & Tukey's graph is only presented at the family level (Fig. 2a), because there were too many species to produce a clear graph. In 1995 and 1998 the polychaete families were placed in three out of four possible categories: dom- inant, restricted and rare. In 1995, in quadrant I (frequent and abundant), 6 poly- chaete families were characterized as dominant. Spionidae, Nereididae, Sabellidae, Lumbrinereidae, Capitellidae and Syllidae families displayed high densities and wide distribution throughout the lagoon. The families Spionidae, Capitellidae, and Sabellidae presented the highest densities and combined accounted for 45% of the total abundance of polychaetes. Ten families restricted to certain areas of the lagoon were located in quadrant IH (non-frequent and abundant) and corresponded to 32% of all families. Within quadrant III (non-frequent and non-abundant), 12 polychaete families were located, classified as rare or occasional. No families were located in quadrant IV corresponding to frequent and non-abundant families. Ap- proximately 35% of species were located in quadrant I (36 species). In 1998 (Fig. 2b), in quadrant I, only 3 polychaete families were characterized as dominant. The families Spionidae, Orbiniidae and Capitellidae displayed high densities and 82 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES Table 2. Polychaete species from San Quintin lagoon, Baja California. Species IBS 1998 AMPHARETIDAE Ampharete labrops Harman, 1961 X Ampharete sp x Amphicteis acutifrons Grube, 1850 x Amphicteis sp Grube, 1850 X CAPITELLIDAE Capitella capitata Fabricius, 1780 xX x Mediomastus californiensis Hartman, 1944 xX x Mediomastus sp X X Notomastus magnus Hartman, 1947 % Notomastus tenuis Moore, 1909 xX x Notomastus sp xX CIRRATULIDAE Aphelochaeta marioni Saint-Joseph, 1894 x Aphelochaeta sp 5 Cirriformia spirabranchia Moore, 1904 X x Monticellina tesselata Harman, 1960 x Protocirrineris socialis Blake, 1996 X Protocirrineris sp x COSSURIDAE Cossura candida Hartman, 1955 xX xX Cossura sp A x as DORVILLEIDAE Dorvillea sp X EUNICIDAE Lysidice ninetta Verril, 1900 x Marphysa disjuncta Harman, 1961 x M. sanguinea Montagu, 1815 x Ke Marphysa sp x xX FLABELLIGERIDAE Pherusa capulata Moore, 1909 X x Piromis arenosus Kinberg, 1867 X x Piromis sp Xx GLY CERIDAE Glycera americana Leidy, 1855 xX G. tenuis Hartman, 1944 xX X GONIADIDAE Goniada brunnea Treadwell, 1906 G. littorea Hartman, 1950 x X HESIONIDAE Podarkeopsis glabra Hartman, 1961 x x Podarke pugettenisis Johnson, 1901 xX % LUMBRINERIDAE Scoletoma crassidentata Fauchald, 1970 X S. erecta Moore, 1904 X S. monroi Fauchald, 1970 X S. tetraura Schmarda, 1860 x X POLYCHAETES FROM THE PACIFIC COAST OF BAJA CALIFORNIA Species MALDANIDAE Axiothella rubrocincta Johnson, 1901 Axiothella sp Verril, 1900 Clymenura gracilis Moore, 1923 Euclymeninae sp A Ardwidsson, 1906 Tsocirrus longiceps Moore, 1923 Maldane sp NEPHTYIDAE Nephtys caecoides Hartman, 1938 Nephtys sp NEREIDIDAE Neanthes caudata delle Chiaje, 1828 Nereis latescens Chamberlin, 1919 N. pelagica Linné, 1758 Nereis sp Platynereis bicanaliculata Baird, 1863 P. marphysa OENONIDAE Arabella iricolor Montagu, 1804 A. pectinata Fauchald, 1970 Drilonereis falcata Moore, 1911 D. longa Webster, 1879 D. mexicana Fauchald, 1970 Drilonereis sp Notocirrus californiensis Hartman, 1944 ONUPHIDAE Kinbergonuphis sp OPHELIIDAE Armandia bioculata Hartman, 1938 A. brevis Moore, 1906 Ophelia pulchela Tebble, 1953 Polyophthalmus picuts Dujardin, 1839 ORBINIDAE Leitoscoloplos mexicanus Fauchald, 1972 L. normalis Day, 1977 Naineris grubei Gravier, 1908 Phylo felix Kinberg, 1866 P. ornatus Verril, 1873 Scoloplos acmeceps Chamberlain, 1919 S. armiger Miiller, 1776 S. ohlini Ehlers, 1901 S. texana Maciolek & Holland, 1978 OWENIIDAE Owenia collaris Hartman, 1955 PHYLLODOCIDAE Eteone pacifica Hartman, 1936 Eteone sp Eulalia bilineata Johnston, 1840 Eumida sp 1995 ~ KK MK x KH KK 1998 84 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES Table 2. Continued. Species 195 1998 POLY NOIDAE Harmothoe imbricata Linné, 1767 * Harmothoe sp % SABELLIDAE Chone infundibuliformis Kroyer, 1856 C. mollis Bush, 1904 Fabricinuda limnicola Hartman, 1951 Megalomma pigmentum Reish, 1963 SCALIBREGMATIDAE Scalibregma sp X SIGALIONIDAE Sthenelais fusca Johnson, 1897 Xx SPIONIDAE Aporionospio pigmaeus Hartman, 1961 x Boccardiella hamata Webster, 1879 X x Microspio pigmentata Reish, 1959 X Minuspio cirrifera Wirén, 1883 x Polydora socialis Schmarda, 1861 P. websteri Hartman, 1943 Prionospio heterobranchia Reish, 1959 P. lighti Maciolek, 1985 Pseudopolydora pauchibranchiata Okuda, 1937 Scolelepis squamata Miiller, 1806 Spiophanes bombyx Claparéde, 1870 S. duplex Chamberlain, 1919 S. missionensis Hartman, 1941 Spio pacifica Blake & Kudenoy, 1978 Spio sp Xx SYLLYDAE Cicese sphaerosylliformis Diaz & San Martin, 2001 Eusyllis sp Exogone lourei Berkeley & Berkeley, 1938 Grubeosyllis mediodentata Westheide, 1974 Pionosyllis sp x Ke Km KK KK OK x KK MK x KK OK ~~ KK KK x 6 mM MK Sphaerosyllis californiensis Hartman, 1966 Syllis aciculata Treadwell, 1945 X S. gracillis Grube, 1840 X 54 S. heterochaeta Moore, 1909 X Syllis sp X TEREBELLIDAE Eupolymnia nebulosa Montagu, 1818 x Pista alata Moore, 1909 X x Pista sp Polycirrus sp X POLYCHAETES FROM THE PACIFIC COAST OF BAJA CALIFORNIA 85 Table 3. Polychaete species recorded in previous studies at San Quintin lagoon, Baja California. Numbers correspond to the different taxa recorded in the area. Reish, 1963 l Anaitides ca. multiseriata 2 Anaitides williamsi 3 Arabella iricolor 4 Arenicola cristata 5 Armandia bioculata 6 Axiothella rubrocincta 7 Brania clavata 8 Capitella capitata 9 Capitita ambiseta 10 Chone mollis 1] Chrysopetalum occidentale 2 Cirrifornia luxuriosa 13 Cirrifornia spirabrancha 14 Cossura candida 15 Dorvillea articulata 16 Eteone dilatae sg Eteone pacifica 18 Eulalia bilineata i Exogone verugera 20 Fabricia limnicola ZA Glycera americana DY Goniada brunnea 23 Hapioscoloplos elongatus 24 Lepidonotus caelorus 25 Lumbrineris erecta 26 Lumbrineris minima De. Marphysa sanguinea 28 Megalomma pigmentum 29 Nephtys caecoides 30 Nereis caudata aul Nerinidaes maculata Si Notomastus magnus 38 Onuphis microcephala 34 Ophiodromus puggettensis 35 Pista alata 36 =. Platynereis bicanaliculata 37 Polydora uncata 38 Polyophthalmus pictus 39 Prionosopio malmgreni 40 Prionospio pygmaeus 41 Scoloplos (L) ohlini 42 Scoloplos acmeceps 43 Scyphoproctus oculatus 44 Sphaerodorum minutum 45 Spiophanes missionensis 46 Trypanosyllis gemmipara 47 Typosyllis variegata 48 Aedicira pacifica 49 Aricidea suecica Armandia bioculata Axiothella rubrocincta Brania clavata Chone mollis Cirrifornia luxuriosa 86 Nn ‘Nn SOUTHERN CALIFORNIA ACADEMY OF SCIENCES Table 3. Continued. Cossura soyeri Eteone dilatae Eteone pacifica Exogone occidentalis Fabricia limnicola Kinbergonuphis microcephala Leitoscoloplos pugettensis Lepidonotus squamatus Lumbrineris erecta Lumbrineris mimima Magelona pitelkai Marphisa sanguinea Mediomastus ambisetus Mediomastus californiensis Megalomma pigmentum Neanthes arenaceodentata Nephtys caecoides Nephtys ferruginea Notomastus magnus Notomastus tenuis Pherusa capulata Phylo felix Pista alata Platynereis bicanaliculata Polyophtalmus pictus Prionospio cirrifera Prionspio heterobranchia Prionospio malmgreni Prionospio newportensis Pseudopolydora kempi Scolelepis maculata Scolopios acmeceps Scyphoproctus oculatus Spiophanes missionensis Apistobranchus sp Arabella tricolor Brada villosa Brania sp. Cirrifornia cf. spirabrancha Chaetozone sp. Chone sp. Clymenura gracilsis Cossura candida Euchone sp. Exogone dispar Exogone louret Goniada maculata Kinbergonuphis cf microcephala Leitoscoloplos mexicanus Lysidice ninetta Marphysa sanguinea Megalomma bioculatum Monticellina tesselata Neanthes acuminata Nereis sp. Notomastus sp. ——— Eee POLYCHAETES FROM THE PACIFIC COAST OF BAJA CALIFORNIA 87 Table 3. Continued. 74 Pionosyllia sp. 75 Polydora socialis TS Praxillela sp. TI Prionospio multibranchiata Prionospio (Minuspio) cirrifera Prionospio heterobranchia 78 Scoletoma tetraura WS) Scoloplos rubra 80 Spio pettiboneae 81 Syllis (Syllis) gracilis when combined accounted for 70% of the total abundance. Seven families re- stricted to certain areas of the estuary were located in quadrant II (non-frequent and abundant) and corresponded to 33% of all families. Within quadrant IIT (non- frequent and non-abundant), 11 polychaete families were located, and correspond- ed to rare or occasional. No families were located in quadrant IV. 25% of species were located in quadrant I (16 species). BSQ exhibited a broad range of species richness per station. Values varied between 6—13 species in heads of both estuary arms and 3—26 species in the middle sections of both basins (Fig. 3). Higher abundance values, more than 100 polychaetes/station were located largely on the southern half of BSQ, only one of these stations was located in the northern part of BF (station 46). In both surveys, SQB presented higher poly- chaete densities and diversity values, probably the oyster aquaculture in BF al- though not intensive has produced a certain impact in the benthic communities due to an excess of organic matter. In 1995, in BSQ several stations presented diversity values higher than 3.50, station 14 had 4.15; three stations (5, 9, 20) reached 25 species. On the contrary, in BF only one station (14) presented a higher value than 3.50 (station 41), seven stations presented diversity values between 3.00 and 3.50, no stations had values higher than 4.00. No station reached an specific richness of 25, the highest value was 19 species in station 22. From the 30 families already reported by Reish (1959), Calder6n-Aguilera (1992), Diaz-Castaneda & Rodriguez-Villanueva (1998), 23 have been found in the present work and six families are added: Ampharetidae, Owentidae, Scali- bregmatidae, Sternapsidae, Dorvilleidae and Sigalionidae. The seven families not found in 1995 and 1998 were: Paraonidae, Magelonidae, Apistobranchidae, Sphaerodoridae, Trichobranchidae, Chrysopetalidae and Arenicolidae. From the 6,443 polychaetous annelids collected in both cruises, representing 104 species, 53% (55 species) correspond to new records for the area. Thirty species were common to both sampling campaigns. One new genus and a new species was found in the eastern arm, in stations 8, 17 and 23 of BSQ: Cicese sphaerosylliformis, reported separately (Diaz-Castaneda & San Martin 2001). From the 104 polychaete species found in 1995, 41% (43 species) are recorded for the first time, whereas from the 65 species collected in 1998, 33% (22 species) correspond to new records. Species richness and diversity were higher in BSQ 88 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES Capac Spionidae aebeoarcdae Vilidae Nereidae Cossuridae Orbiniidae — Ophelidae + Terebellidae (= iC eaaae ee Goniadidae®""" a oO) Glycer eridae Le, Eunicidae Ela SCGEE > Nephtyidae a Maldanidse 2) ee (‘S omer hidae (ab) p mpfjaretidge e Dorv ifeidae Polynoidae _Oweniidae Scalibregmatidae Spionidae Syllidae Capitellidae Orbiinidae —< Sabellidae — Cirratulidae + = oD) Cossuridae Lumbrineridae ce) Opheliidae | Oenonidae Fabel eridae ‘= Bee Waldahidae 7) Eunicidae Nereididae S Hesionidae 0) Goniadidae a) Phyllodocidae Terebellidae Onuphidae Nephtyidae Glyceridae 0 20 40 60 80 100 Frequency (%) Fig. 2. Relationship between frequency (%) and density (org. 0.1 m*) of polychaete families using Olmstead and Tukey’s technique: a) 1995 B) 1998. POLYCHAETES FROM THE PACIFIC COAST OF BAJA CALIFORNIA 89 30 25 - = ® ” ro} & £ O 20 D a S [ras oO x< = 15 = oO £ & (e 3) oO Z 10 = 140) AS op) 5 0 0 5 (Ome 15.0 70e 25 6a0,. 235" 40 45 50 Stations = e oe 7) = £& ® 2 a S xe) © = Oo g f= = 5 z = 14) ce op) 0 5 10 45 20 25 30 35 40 45 Stations Fig. 3. Diversity (H’) and species richness of polychaetes collected in both surveys: a) 1995, b) 1998. (Fig. 3), 11 stations in BSQ had diversity values higher than 3.5, only station 40 located in the northern section of BF presented a diversity value higher than 3.5. Although abundances were similar in 1995 and 1998, we noted a change in the composition and structure of the polychaete communities; species richness 90 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES diminished signficantly from 104 to only 65, reflecting the diminution of diversity values and equitability of the communities. The trophic structure also changed as deposit-feeders increased their numbers, and the abundance of other trophic cat- egories diminished, indicating a modification in community organization and loss of complexity. Significant variations in the abundance of some important families were de- tected between 1995 and 1998; some increased their abundances: Spionidae from 17% to 48%, Orbiniidae from 4% to 13%. These families are essentially deposit- feeders although some species of spionids can also feed as filter-feeders. Other families decreased in terms of number of species: Lumbrinereidae from 11% (4 species) to 1.4% (1 species), Nereididae from 9% © species) to 1% (omlyaz species) and Sabellidae from 14% to 5% (3 species). Lumbrinereids live in sand or mud, in plant roots or in algal hold-fasts, nereidids are omnivores and herbi- vores and sabellids are filter-feeders. These modifications changed the diversity and structure of polychaete communities in this lagoon. Diversity values ranged between 1|.18—4.04 in 1995, and 1.10—3.51 in 1998, with higher values mainly located in BSQ, especially the middle section (Fig. 3). Diversity in BF diminished in 1998, reaching a maximum of 2.71. In 1995, 55% of stations presented equitability (Pielou index) values higher than 0.800, indi- cating a more or less even distribution of polychaetes at the species level. Whereas in 1998 only 35% of stations reached more than 0.800. BF presented in both surveys lower equitability and diversity values, probably this is related to the increasing oyster culture which seem to affect the benthos due to negative Eh values. Values of species diversity (H’) and evenness (J’) for stations sampled were analyzed and placed into four “‘environments’’ (Fig. 4) as defined by the Stress- Predictability modeling (Alcolado 1992). We found seven times more stations classified in environment I (very favorable and stable) in 1995 compared to 1998. In 1995 (Fig. 4a), environment I, which included 21 stations with the highest values of diversity (H’) (2.52—4.04) and evenness (J’) (0.740—0.910), was char- acterized as being very favorable and stable. Environment II was represented by 11 stations (10, 13, 21, 24, 26, 28, 32, 33, 34, 38, 42) located in the middle areas of BSQ and BE it was favorable and stable, H’ values ranged between 2.68—3.62 and J’ values between 0.694—0.910. Environment III (stations 2, 3, 4, 15, 37, H’ 2.41—2.89, J’ 0.653—0.849) was characterized as being constant, with a degree of environmental stress. Finally, environment IV which corresponded to stations 18, 35, 36 and 39, was moderately favorable, with unstable conditions and a certain degree of environmental stress. Environment IV station diversity values (H”) os- cillated between 1.17—2.83, evenness values (J”) from 0.700 to 0.960, and were the lowest of this study. Whereas in 1998 (Fig. 4b), environment I included only 3 stations (6, 15, 25) with the highest values of diversity (H’) (3.24—3.52) and evenness (J') (0.777— 0.878), was characterized as being very favorable and stable. Environment II was constituted by 10 stations (2, 3, 4, 10, 11, 12, 13, 14, 18, 21) situated mainly in the medium section of BSQ, it was favorable and stable, H’ values ranged between 2.42—3.18 and J’ values between 0.723—0.918. Environment III increased with respect to 1995 survey, it was formed by 12 stations located in both arms (5, 8, 9, 16, 19, 26, 27, 32, 35, 36; 39) 43), H’ 2.16—2.51; J’ 0.575—0.836) charactenzed POLYCHAETES FROM THE PACIFIC COAST OF BAJA CALIFORNIA oil Diversity (H’) 4 OLOROM PO OSs O14 0!5 106) 0'7 70!850:9) 1:0 O10 O81, 0'2 1033) 0:4, 0 O16 0:7 1018) 09) 120 Evenness (J’) Evenness (J’) Fig. 4. Stress-Predictability modeling (Alcolado 1992). Stations are located in different environ- ments: I Very favorable and stable, IH favorable and stable, HI constant with a degree of environmental stress, IV moderately favorable, unstable conditions and a certain degree of environmental stress. as being constant, with a degree of environmental stress. Finally, environment IV which corresponded to stations 30, 33, 34, 38, 40, 41, 42 and 45, located in the middle of BF was moderately favorable, with unstable conditions and a certain degree of environmental stress. Environment IV station diversity values (H”) os- cillated between 1.56—2.16, evenness values (J"”) from 0.640 to 0.831, and were some of the lowest of this study. The number of stations in this last category almost doubled in relation to 1995. In relation to trophic groups, polychaete species found in 1995 and 1998 were in decreasing order of importance: deposit-feeders, carnivores, filter-feeders and herbivores. Deposit-feeders increased their numbers in 1998. We also detected an important presence of carnivores, essentally syllids, which increased their abun- dance in 1998. Spionidae and Capitellidae which were among the most abundant families have species which are surface and subsurface deposit-feeders, as well as filter-feeders. The dominant species Prionospio heterobranchia can feed as a deposit-feeder or as a filter feeder, this capacity allows them to stay and even increase their abundances in disturbed conditions. The families best represented in 1995, by decreasing order of importance were Capitellidae, Spionidae, Sabellidae, Lumbrinereidae and Nereididae, they changed in 1998: Spionidae, Orbiinidae, Capitellidae, Syllidae, Sabellidae. Bray-Curtis coefficient of similarity was used to measure the level of associa- tion of samples. The dendrogram (Fig. 5a) generated with samples and replicates from 1995 revealed a clear separation between both arms, to the right of the graph are located BSQ samples and to the left BF samples (except stations 4 and 15). BF revealed four groups at 30% level of similarity: group I with 6 stations from 92 % Similarity Bray-Curtis % Similarity SOUTHERN CALIFORNIA ACADEMY OF SCIENCES 0 a 1995 20 AO 60 80 100 WON K OTTOWOF-MOTONTTAOODOT MD OWDOATOMNMMNKIANWONMNMNOODOOS cotonnadiacanuseok. ee SSSesSIFTeeussas AMNMAMNAMMNHTTTOOOTT NANNAAISKH NNNAN - Aree on teath oel | NA TAT KAT NN KN northBF I Ii ito ov ete Me ee VII Vv et BF SO b 1998 20+ 40+ IB IA 60 80 100 OO AmMOM OWMm OW NN SS Om ASS OO O10 Nos Ata — ~~ oO Clow oOo S=—GQN) xt (GQ '®) (6D) (QU GAN GNI SE QE NY (OCD) CO) CO) St = OO SS id ne! ee GN nee I lau SQ & north BF middle SQ north SQ south SQ & mouth & SS a a SS middle BF south BF If! Fig. 5. Bray-Curtis dendrogram showing classification of stations sampled in 1995 (a) and 1998 (b). POLYCHAETES FROM THE PACIFIC COAST OF BAJA CALIFORNIA 93 the middle and mouth, group II formed by six stations from the southern section and mouth, group HII constituted by five stations from the north and near the mouth and group IV formed by 6 stations from the western section. Groups II and IV are formed by stations from the northern section which is the least well flushed. At the left of the figure appear 9 stations connected to the other groups with low levels of similarity. At 42% similarity SQB samples are separated into three groupings: group V comprised 21 stations, it is subdivided in two groups, VA constituted by 13 stations located in the middle and south and VB formed by eight stations from the north, group VI gathered seven stations from the middle and south and group VII is constituted by 12 stations from the middle section of the bay. The dendrogram (Fig. 5b) generated with samples from 1998 revealed also a separation between both arms, although it is less clear than in 1995. To the right of the graph are located mainly SQB samples and to the left most of BF samples. At 30% level of similarity which correspond to a faunistic dissimilarity for the bay we observe 3 groups: group I formed by 13 stations from middle SQB and east BE at a higher level of similarity it is subdivided in two groupings IA formed by stations from middle BF and south BSQ and IB which gather stations from the southern half of BSQ. Group II formed by four stations located near the mouth and group III constituted by 18 stations subdivided in three groupings which represent respectively north BF and middle BSQ, middle BSQ and north BSQ. Factorial Correspondence Analysis (FCA) and non metric MDS were applied to a matrix of 104 species and 45 stations in 1995, and a matrix of 65 species and 42 stations in 1998. Data treated correspond to the polychaete species abun- dances. Some representative graphics were selected. In 1995, the first two axis extracted 45.5% of total inertia. In the factorial plane 1—2 we observed that samples from each lagoon arm gathered, forming BF and BSQ two separate groups in the factorial space (Fig. 6a). Most of the stations of BSQ were located on the positive side of axis 2 whereas all stations of BF were situated in the negative side of this axis which indicate that polychaete commu- nities inhabiting each lagoon arm are not exactly the same, even if the species list is similar, the proportion between species change. This can be explained by the fact that hydrological conditions are not the same in both arms, depth averages are 4 and 8 m in BF and BSQ respectively. Conditions in BF can favor the development of more sensible species, those that can not tolerate very low oxygen concentrations and/or very negative Eh values because in this arm the water ex- change with the sea is faster (Diaz-Castafeda & Rodriguez-Villanueva 1998). However if oyster aquaculture increases, it may cause a negative effect in the water and sediment quality, affecting these species. In 1998, the first two axes extracted 55.2% of total inertia. In the factorial plane 1-2 (Fig. 6b), BF stations appear together, forming two groups. One of the groups is located on the positive side of axis 2, the second group which correspond to the southern section is situated on the negative side of this axis, near the stations from north BSQ. BSQ stations form a group that extends along axis |, the stations from the north (negative side of axis 2), middle and southern sections differentiate. Polychaete communities were also examined using non metric multidimension- al scaling. This analysis also provided evidence of a separation between samples of the eastern and western arms of the bay. MDS analysis applied to data from 94 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES a) 2(14.5 %) S. Quintin south —_— 1(31.0%) mouth middle S.Q. (esto) B. Falsa b) 2(20.3 %) south S. Q. B. Falsa we 1(34.9%) . south B.Falsa Fig. 6. Factorial Correspondance Analysis (FAC) ordination of sampled stations in Bahia San Quintin. POLYCHAETES FROM THE PACIFIC COAST OF BAJA CALIFORNIA 5 a) stress = 0.15 eB. Falsa o S. Quintin stress = 0.13 eB. Falsa o S. Quintin Fig. 7. Non-metric multidimensional scaling (MDS) ordination of stations sampled in 1995 (a) and 1998 (b). 1995 (Fig. 7a) revealed a group of stations located in the center which correspond to BSQ; to the right are located stations from the northern area. Around these stations are located those from BE The stations near the mouth are surrounded by a dotted circle. Stress value (0.15) indicated that the configuration was a good representation of the faunistic similarities between stations. In 1998 (Fig. 7b) the separation between stations from BSQ and BF is also observed but not so clearly, stations from north BSQ are situated in the right and upper section. Most BSQ 96 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES stations are located in the right side, while BF are mainly in the left. Stress value is 0.13. The mouth stations are essentially located in the same position than in WS). In conclusion, the study of polychaete communities in both arms of San Quintin lagoon showed in both surveys differences in species diversity, composition of species and abundances. Polychaete communities seemed to have balanced ac- cording to the physico-chemical characteristics prevailing in the area in 1995 and 1998. The proportion of families changed, some families disappeared completely in the 1998 survey: Dorvilleidae, Polynoidae, Owentidae, Scalibregmatidae, Ster- napsidae, Sigalionidae. Seven families found in 1992 (Diaz-Castaneda & Rodri- guez-Villanueva 1998) were not collected in 1995 or 1998: Paraonidae, Mage- lonidae, Apistobranchidae, Sphaerodoridae, Trichobranchidae, Chrysopetalidae and Arenicolidae. The eastern arm (SQB) presented in both surveys, higher polychaete densities and diversity values, probably the oyster aquaculture in Falsa Bay although not intensive has produced a certain impact in the benthic communities due to an excess of organic matter, resulting in negative Eh values and reduction of abun- dance and diversity. Comparing the polychaete composition and the values of some ecological indexes (Shannon Index, Pielou, Simpson dominance) between 1995 and 1998 we detected an important diminution of the species richness and diversity. In BSQ several stations presented diversity values higher than 3.50, one station had more than 4.0; in BF only one station presented a higher value than 3.50, no stations had values higher than 4.0. Higher species richness values were located in BSQ (up to 26/station), indicating that this is an adequate environment for polychaetes development. It seems that the physico-chemical characteristics pre- vailing in each arm, as well as water exchange rates influence benthic commu- nities development. The mathematical methods applied allowed a better global vision of the organization and structure of these populations. Increased environmental variability due to the ENSO 97—98 probably may have affected recruitment, survival and reproductive patterns of polychaete species, modifying the composition and structure of polychaete communities between 1995 and 1998. In Chile, Escribano et al. (2004) found increased benthic biotur- bation during the same period. Probably there was seagrass reduction (Zostera marina) in 1998 that could have indirectly affected zoobenthic recruitment, which is partially driven by the hydrodynamic environment modified by seagrass mead- ows, as has been observed by other authors (Bostrom & Bonsdorff 2000). Finally, in San Quintin lagoon more than 50% of stations had relatively high values of diversity and evenness, indicative of healthy benthic communities. In general, the bay is characterized by high diversity values and approximately 70% of stations were favorable and constant environments for polychaetes, especially in the southern area of BF where the bivalve culture takes place and the middle section of BSQ. Acknowledgements We would like to thank E. Gutiérrez for his help during field work in 1995. G. de la Selva and M. Necoechea for helping sort the macrofauna and C. Almeda for his help with statistical programs. J. 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Southern California Acad. Sci. 104(2), 2005, pp. 100-112 © Southern California Academy of Sciences, 2005 Composition of the Epifaunal Community Associated with the Seagrass Zostera marina in San Quintin Bay, Baja California Patricia Quiroz-Vazquez,'? Silvia E. Ibarra-Obando,** and Alf E. Meling-Lopez> 'Present address: University of Manchester, School of Biological Sciences 1.30, Stopford Building, Oxford Road, Manchester M13 9PT, UK 2Centro de Investigacion Cientifica y Educacion Superior de Ensenada (CICESE). Km 107 Carretera Tijuana-Ensenada, Ensenada, Baja California 22830, México Departamento de Investigaciones Cientificas y Tecnolégicas de la Universidad de Sonora (DICTUS). Rosales y Nifios Herdes S/N, Hermosillo, Sonora, México Abstract.—The epifaunal community associated with eelgrass beds in San Quintin Bay, Baja California, Mexico, was studied from April to November 1993. Tax- onomic identification, univariate community descriptors, and biomass data were obtained for each sample. Multivariate analyses of community composition were also performed, and plant—animal relationships were analyzed. The epifaunal com- munity was characterized by the high abundance of a few dominant species, with the mollusk Assiminea dubiosa representing 70% of the total abundance. Summer samples had the highest similarity, as indicated by the Analysis of Similarity (ANOSIM) test. Polychaetes and amphipod abundances seemed to follow the variations in eelgrass aboveground biomass. Seagrasses are aquatic angiosperms with a high degree of uniformity in their vegetative appearance. Almost all genera have well-developed subterranean rhi- zomes and strap-shaped leaves. There is however, a considerable degree of di- versity in the mode of growth, the branching system, and in the anatomical struc- ture (Den Hartog 1967). Seagrasses grow in suitable shallow marine waters world- wide, and are represented by 7 tropical and 5 temperate genera (Den Hartog 1970). Although present across only 0.15% of the ocean surface, they account for about 1% of the net primary production and 12% of the net ecosystem production of the global ocean (Duarte and Cebrian 1996). Seagrasses are among the most productive autotrophic communities on the planet (Hillman et al. 1989; Duarte and Chiscano 1999). Their high biomass and production is directly linked with their important role in the ecosystem. For this reason, seagrasses have been considered among the most valuable ecosystems in the world in terms of the value-added services they provide (Costanza et al. 1997). Ecological functions associated with seagrasses include nutrient recycling, de- tritus production and export, sediment stabilization, and provision of optimal hab- itat for growth, survival and reproduction of a diverse array of vertebrate and invertebrate taxa (Heck et al. 1997, 2003). Further, biodiversity generally appears to be higher in seagrass relative to adjacent habitats (Orth et al. 1984; Bell and *“ Corresponding author. E-mail: sibarra@cicese.mx 100 EPIFAUNA IN EELGRASS BEDS OF SAN QUINTIN BAY i01 Pollard 1989; Orth 1992), although the magnitude of this difference depends on seagrass species composition and biomass (Heck et al. 2003). For this reason, seagrasses are viewed as extraordinarily rich habitats (Kikuchi 1980; Heck et al. 2003). Recent theories on mechanisms controlling energy flow in seagrass beds em- phasize the importance of intermediate trophic levels, with large invertebrates acting as effective predators on the smaller invertebrate fauna (Klumpp et al. 1989) and small invertebrate grazers controlling epiphytic algal abundance (van Montfrans et al. 1982; Hootsman and Vermaat 1985). Experimental research has shown important top-down effects in determining the composition and abundance of seagrass-associated plants and animals in natural conditions, thus supporting the hypothesis that small grazers can often control the abundance of epiphytes, and emphasizing the need to know how grazer populations are regulated in order to fully understand the consequences of human perturbations (e.g. nutrient en- richment) on seagrass ecosystems (Heck et al. 2000). With this functional perspective in mind, and recognizing the urgent need to have detailed information on the composition of the mobile fauna in San Quintin Bay, we collected data on the epifaunal and mobile species assemblages. We here present the epifauna data, for which we first characterized the species composition, performed univariate community analysis, and calculated biomass. We then per- formed multivariate analysis of community composition, and analyzed plant—an- imal relationships using correlation analysis. Our data on species composition, changes in community composition over time, and plant—animal relationships were compared with those reported for other locations, and other seagrass species. Materials and Methods Study Site San Quintin Bay is a Y-Shaped coastal lagoon located on the Pacific coast of Baja California. The east arm is known as Bahia San Quintin, and the west arm as Bahia Falsa (Fig. 1). The bay covers an area of about 42 km? and has a mean depth of about 2 m. Tides are semidiurnal with a mean amplitude of 1.6 m (C. Nava, Sea Level Laboratory, CICESE, personal communication). Water exchange with the coastal ocean is intense, with about 11 days water residence time for San Quintin Bay, and 4 days for Bahia Falsa (Camacho-Ibar et al. 2003). Water temperature ranges from 13 to 27°C inside the bay and from 11 to 22°C at the mouth (Alvarez-Borrego and Alvarez-Borrego 1982). Total evaporation in summer (164 X 10° m?* day~') and winter (91 xX 10° m3 day ') exceed total rainfall (4 < 10° m? day '), and there is ordinarily no signif- icant runoff or groundwater inflow. Consequently, San Quintin Bay is a net evap- orative system (Ibarra-Obando et al. 2001), with summer and winter salinities in the interior (38.7—33.8%c) always higher than in the adjacent ocean (33.8—33.6%c) (Millan-Nunez et al. 1982). San Quintin Bay is characterized by extensive eelgrass (Zostera marina) beds, best developed in the middle bay on soft sediment bottom plains that are covered with between 0.3 m and 0.9 m of water at the lowest tide. Present eelgrass cov- erage 1s about 40% (Ward et al. 2003). The benthic invertebrates of vegetated and unvegetated areas have been studied, both at the taxon level (Keen 1962; 102 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES — 30930’N NY “sf \ 30°25’N - ~ SS a, OQ S mudflat % seagrass lagoon channel 0 5 10 Se TOS eae Km zi 30°20'N 116°00'W 115°55'W be Fig. |. Location of the sampled area inside San Quintin Bay, Baja California, Mexico (modified from Ibarra-Obando et al. 2004). Reish 1963; Barnard 1964; Cook 1974; Calder6n-Aguilera and Jorajuira-Corbo 1986; Bretado-Aguirre 1987; Cantu-Martinez 1987; Griffis and Chavez 1988; Diaz-Castaneda and Rodriguez-Villanueva 1998), and at the community level (Barnard 1970; Calderon-Aguilera 1992; Sinicrope-Talley et al. 2000). Environ- mental conditions that play a role with the macro-infaunal (animals = 0.3 mm) EPIFAUNA IN EELGRASS BEDS OF SAN QUINTIN BAY 103 distribution inside San Quintin Bay include: distance from the mouth, gradients of tidal amplitude, changing hydrodynamics, seasonal runoff, and a breakdown of the typical inverse-estuary currents by overriding unidirectional winds (Sini- crope-Talley et al. 2000). Oyster aquaculture, low-density tourism and fisheries are the main economic activities, none of which has significantly negatively impacted the bay up to this point. Doubling of aquaculture and construction of tourist mega-resorts are po- tential threats for the next decade (Aguirre-Munoz et al. 2001). Field Work Samples were collected from the west arm, Bahia Falsa, in front of the fish camp known as “El Chute” (Fig. 1). Sampling took place in April, May, July, August, October, and November, 1993. Fauna associated with eelgrass were col- lected at high tide with a trawl net with metal frame of 0.4 < 0.5 m (2.54 cm mesh size) with a cod end of 1 mm mesh size. Each trawl lasted one minute at a constant speed of one knot, and covered about 15 m?’. A total of six trawls were done during the study period (one each sampled month). In the field, samples were fixed in 10% formaldehyde, and transported to the laboratory in buckets. In the laboratory, samples were rinsed several times with fresh water, and plant material was separated from animal material. Seagrass leaves, roots, and macroal- gae were washed in sieves of 2 and | mm. Once the organisms were separated, they were placed in glass jars, preserved in 70% isopropyl alcohol, counted under the microscope, and identified with taxonomic keys for each group. Biomass, as dry weight (DW), was obtained by drying organisms in an oven at 105°C for 12— 24 hrs. Large organisms were cut into small pieces and once dried, the material was homogenized in a blender, and 4 or 5 sub samples were used for AFDW determination. The ash free dry weight biomass (AFDW) was determined after burning the dry organisms in a muffle furnace at 550°C for 4—6 hrs (Brower and Zar 1977). Biomass per trawl and per m? was determined. Eelgrass samples were collected from a 4.8 ha mudflat in front of ““El Chute’’, along a 300 m long transect in the intertidal (—0.10 m with respect to Mean Lower Low Water, MLLW). Sampling took place at every spring tide. To assess eelgrass biomass, 7 random samples were collected using a 0.04 m? quadrat on each sampling date. Only aboveground material was collected. Samples were washed with seawater, using a | mm mesh sieve. All material was placed in labeled plastic bags and kept cool until transported to the laboratory. Rinsed samples were sorted to calculate shoot density. Aboveground material was pro- cesses as described in Poumian-Tapia and Ibarra-Obando (1999). Data Analysis For each sample, univariate community measures were determined: abundance (number of individuals, N), richness (number of species, NO), diversity (N1), evenness (Pielou’s J’), and dominance (Krebs 1985). Relative abundances and densities for each species in each sample were also obtained. Diversity was mea- sured by Hill indices (Hill 1972), as they take into account the Shannon-Weaver diversity index, and the Simpson diversity index: 104 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES NO. = S; Nika N2 = I/\; . where S = number of species; H’ = Shannon Index; h = Simpson Index As the Shannon-Weaver index and the Simpson index are affected by sample size, and number of organisms per sample, their joint use can reduce the bias in diversity assessment (Hill 1972). Dominance of the different species was esti- mated using the Importance Value Index (I.V.I.) that combines three determinant characteristics of the importance of any given species in the community: abun- dance, frequency and biomass (Krebs 1985): LV.I = @®N + @F + @B, where YN = relative abundance; %F = relative frequency; %B = relative biomass In order to identify differences and similarities in epifaunal community com- position between samples, we performed a Non-metric Multidimensional Scaling (MDS) (Ludwig and Reynolds 1988). For this purpose, data were organized into abundance, and presence-absence matrices that were simplified by eliminating those species present in only one sample (F<16%), and in relatively low abun- dances (<0.001% of sample total abundance) (Stephenson and Cook 1980). Total abundance data were transformed to the 4" root of n to reduce the variability between values (Clarke and Green 1988). Seasonal variations were analyzed with a two-way nested Analysis of Similarity and (ANOSIM) test (Clarke and Warwick 1994), in which months were nested in seasons. For all tests, confidence level was set at 0.05. The relationships between epifauna richness, and abundance, and eelgrass den- sity and aboveground biomass were analyzed with a Rank Correlation Analysis (Zar 1966). Results Univariate Measures of Community Composition The average number of organisms per trawl was 52,836+16,703 (+1 S.E.), representing 74 taxa belonging to four major groups: polychaetes, crustaceans, mollusks, and fishes. At the group level, species richness was highest for poly- chaetes and crustaceans, with 24 species each, representing 32% of the total spe- cies richness. Amphipods were the most frequent crustacean taxa, accounting for IS of the 24 identified taxa. Fishes represented only 11% of the total, with 8 species. Of the 317,015 organisms collected, mollusks contributed 71% of the total abundance, followed by crustaceans, with 28%. Crustaceans and fish had the highest biomass, about 37% each (Table 1). Of the 74 taxa collected, the 6 most abundant species were the mollusk, As- siminea dubiosa; the caridean, Hippolyte californiensis; the amphipods, Amphitoe plumosa, Corophium baconi, Hyale nigra and Erichtonius brasiliensis. The mol- lusk A. dubiosa represented 70% of the total abundance, and was the only species present in all-samples. The next numerically important species was H. califor- niensis making up 5% of the total number of individuals. The four most abundant and common polychaete species and their total abundance per trawl were as fol- lows: Platynereis bicanaliculata (2,280); Polydora cirrosa (207); Exogone lourei EPIFAUNA IN EELGRASS BEDS OF SAN QUINTIN BAY 105 Table 1. Richness, abundance, and biomass values and percentages for each epifaunal group found in San Quintin Bay between April and November 1993. Values represent the total of 6 trawls. NO = number of species; N = number of individuals. Biomass is expressed as g of Ash Free Dry Weight (AFDW). Richness Abundance Biomass Group NO Yo N % g (AFDW) % Polychaetes 24 32.4 2,899 OS 0.44 0.2 Crustaceans 24 B24 88,981 28.06 SHES 36:55 Mollusks 18 24.3 224,672 70.8 63.6 26.6 Fishes 8 10.8 507 0.16 87.9 367 Total 74 99.9 SI TLOLS 99.9 239.4 100 (142), and Eulalia bileneata (105). The dominating abundance of the first species is evident. The species with highest biomass was H. californiensis, comprising 32% of the total biomass, followed by A. dubiosa with 15%. Two fish species, Syngnathus leptorhynchus, and Embiotoca jacksoni had a similar contribution to total biomass (12%). The remaining 70 species had biomass values that represented between 7 and <1% of the total. According to the I.V.I., the community was dominated by the following species: A. dubiosa, 88.5; H. californiensis, 40.1; S. leptorhynchus, 15.2; E. jacksoni, 13.8, and H. nigra, 10.0. Values for the different community descriptors for each sampling time are pre- sented in Table 2. No clear trends could be identified, given the limited number of trawls performed during this study. Multivariate Measures of Community Composition Ordination analysis using total abundances showed three well defined groups, which correspond to spring (April-May), summer (July—August), and autumn (October-November). The highest similarity was for the summer samples (80%) (Fig. 2). Spring and autumn groups were defined by A. dubiosa and H. califor- niensis. During summer, besides A. dubiosa, amphipods of the order Gammaridea (e.g. Corophium baconi, Erichtonius brasilensis, H. nigra) made a significant contribution (Table 3). Plant—animal Relationships A significant positive correlation between epifaunal diversity and eelgrass aboveground biomass was observed (r = 1, p<0.05), but no other significant Table 2. Values obtained for the different community descriptors on each sampling date. April May July August October November Abundance (N) 633526 45,673 60,734 TEPON) 46,448 272A Species richness (NO) 27 34 39) ai 35 53 Diversity (N1) 1.50 2.49 4.28 5.08 2.76 4.05 Eveness (J’) 0.12 0.26 0.40 0.45 O29 135 Biomass (B) 30.62 76.47 31.87 LOX7 1 58.89 PHN ESNY) 106 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES Fig. 2. MDS plot showing the relationship between samples using the simplified matrices of abundance. correlations were identified. Changes in amphipods and polychaetes abundance seemed to follow those of eelgrass aboveground biomass (Fig. 3a and b). Discussion The four major groups that constitute the epifaunal community in San Quintin Bay played different roles in characterizing the community: mollusks were the most abundant; polychaetes and crustaceans both had the largest numbers of spe- Table 3. Species that determine 50% of sample similarity based on abundance (individuals per trawl). Seasonal Group Taxon Contribution (%) Cumulative % Spring A. dubiosa 2O15 20.15 H. californiensis 10.83 31.338 E. brasilensis 5.93 37.26 C. baconi 5.60 42.86 Rhachotropis inflata 5.54 48.4 Amphilochus neapolitanus Byes. S305 Summer A. dubiosa 14.05 14.05 H. nigra 9.14 Dies A. plumosa 8.13 Sf a2 C. baconi 7.18 38.50 E. brasiliensis 6.24 44.74 R. inflata S575 50.49 Autumn A. dubiosa 14.25 14.25 H. californiensis 8.43 22.68 E.. crenulata 7.04 29.72 H. nigra 6.68 36.40 A. plumosa 6.20 42.60 C. baconi 4.81 47.41 P. bicanaliculata 4.61 52.02 EPIFAUNA IN EELGRASS BEDS OF SAN QUINTIN BAY 107 35000 a) 200 30000 25000 20000 15000 10000 5000 e Stila E 2 A S 3 =a ma April May July Aug Oct Nov Fig. 3. Seasonal patterns of (a) amphipods abundance (individual trawl~') [[_]], and eelgrass bio- mass (g DW m 7”) [@]; (b) polychaete abundance (individual trawl!) [[_]], and eelgrass biomass (g DW m~”) [@]. cies; and crustaceans and fishes had the highest biomass. Community composition differed over time, with the summer assemblage having the highest similarity. Finally, amphipod and polychaete abundances seemed to follow the seasonal var- iations in eelgrass aboveground biomass. Mollusks represented 71% of total abundance in San Quintin Bay. Similar high percentages have been reported in other eelgrass beds (e.g. Marsh 1973; Thayer et al. 1975), as well as in beds of other seagrass species (e.g., Virnstein and Howard 1987; Nakaoka et al. 2001). As an example, in the eelgrass beds of North Carolina, gastropods represented up to 72% of the total numbers of epifauna found in the ecosystem (Thayer et al. 1975). We found high species richness for polychaetes, and crustaceans (Table 1). Reish (1963), Calder6n-Aguilera (1992), and Diaz-Castafeda and Rodriguez-Vil- lanueva (1998) report similar results for polychaetes in San Quintin Bay. Similar results were reported by Gambi et al. (1992), Colognola et al. (1984), and Mazella et al. (1989) in a Posidonia oceanica bed in the Gulf of Naples. Crustaceans were the second group with high species richness in our study site. A high crustacean richness (46%) was also reported for San Quintin Bay by Villareal (1995), and by for a mixed Zostera bed in Otsunhi, Japan (56%) by Nakaoka et al. (2001). The high contribution of crustaceans to epifaunal biomass that we found during 108 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES this study, about 37%, has also been noted for other sites. For the Heterozostera tasmanica beds in Western Port, Australia, Edgar et al. (1994) found that the large contribution of crustaceans to biomass was influenced by the presence of eight large filter-feeding brachiopods. Seasonal differences in epifaunal community abundance in eelgrass beds, with peak values during summer, have been reported by Thayer et al. (1975), Heck and Orth (1980b), and Orth and Heck (1980). Edgar (1990) reported a similar pattern in Amphibolis beds, and Coles et al. (1993) found the same trend for eight species seagrass beds in Cairns Harbour, Australia. With the limited data set that we have at present for San Quintin Bay we are unable to describe seasonal var- lations; however, the MDS test on total abundance identified three groups corre- sponding to spring, Summer and autumn respectively (Fig. 2), with the summer group having the highest similarity (ANOSIM test). During our study, amphipods made an important contribution to the definition of the summer group, as they reached their maximum abundance and biomass during this season (Table 3). This seasonal pattern differs from the one reported by Nelson (1979), in Beaufort, North Carolina, who found amphipod density, number of species, and diversity to be low in July—August, and higher in January— February. Nelson (1979) suggested that the observed amphipod change was the result of predation by the pinfish Lagodon rhomboides. In San Quintin Bay, S. leptorhynchus has been described as the most abundant fish species, attaining its maximal abundance in May and November (Rosales-Casian 1997). This differ- ence in life cycle between the fish (predator) and the amphipods (prey) could help explain the differing periods of peak abundance and biomass for these two lo- calities. Applying univariate community measures in the intertidal Zostera novazelan- dica beds in northern New Zealand, Turner et al. (1999) found few consistent seasonal or annual trends over a two-year period. Multivariate analysis (Canonical Correspondence Analysis) applied at the scale of the patches revealed that spatial structure explained 1—2% of the variation in species abundance, environmental variables explained 3—4%, temporal variability explained 12—14%, and 75% of the variation remained unexplained. Turner et al. (1999) attributed the large con- tribution of temporal variability to the explained variance as a reflection of the seasonal and annual trends in the number of individuals, and in the species pres- ent. Our data for San Quintin Bay also seem to reflect a high temporal variability and could indicate the existence of ephemeral assemblages that change in response to a complex set of physical and biological variables, including the annual vari- ations in eelgrass aboveground biomass. The high abundance of a few dominant species that we found during this study, with six species accounting for 93% of the total abundance, is similar to what has been reported for other seagrass beds. For example, Marsh (1973) in the eelgrass beds of the York River, Virginia, found that the five most abundant species accounted for about 60% of the total. Heck and Orth (1980a) in the eelgrass beds of the Lower Chesapeake Bay, found that six species of macroin- vertebrates made up nearly 68% of the total. We cannot compare our absolute values of epifaunal abundance and richness with those reported by other authors, because sessile, creeping or walking epifauna are not collected reliably by trawling (Heck and Orth 1980a). As a consequence, EPIFAUNA IN EELGRASS BEDS OF SAN QUINTIN BAY 109 our values represent underestimations of abundance and richness. A further lim- itation we faced was the reduced number of trawls and the lack of replicates to assess the within-month variability. As a result, the information provided in this study should be considered preliminary. While some authors have found a good relationship between plant-animal den- sity and biomass (e.g. Heck and Orth 1980b; Orth and Heck 1980; Stoner 1980; Lewis and Stoner 1983; Edgar and Robertson 1992; Webster et al. 1998), others have not (e.g. Virnstein and Howard 1987; Edgar 1999). For San Quintin Bay, Sinicrope-Talley et al. (2000) found a correlation between the presence of Zostera and a few taxa of macrofauna, but only in combination with sediment properties. Our data show a significant positive correlation between epifaunal diversity and eelgrass aboveground biomass. Amphipod and polychaete seasonal trends seemed to match the seasonal change in eelgrass aboveground biomass (Fig. 3a and b). These results seem to indicate an association between the above-mentioned epi- faunal species and eelgrass leaves, and can be compared with the diverse, leaf- associated faunal assemblage that Edgar and Robertson (1992) described in the Amphibolis beds at Seven Mile Beach, Australia, which was negatively affected by seagrass thinning. For mixed seagrass beds in North Carolina, Hovel et al. (2002) found that seagrass shoot biomass strongly influenced shrimp densities in 1992, but no correlation was found the previous year. We are aware of the extreme variability of the above-mentioned relationships for San Quintin Bay, and of the need for repeated samplings to establish reliable plant-animal associations. Hovel et al. (2002) found that different faunal species or species groups may respond to different aspects of seagrass habitats, and concluded that the high variability in seagrass landscape structure does not necessarily correspond to variability in faunal abundance. Rather, myriad processes operating at a variety of scales make relationships between fauna and environmental variables complex and difficult to predict. Conclusions The epifaunal community in San Quintin Bay was characterized by the high abundance of a few dominant species. Different assemblages were present throughout the study period, reflecting the seasonal changes of the various species present, as well as the changes in environmental conditions. The summer group had the highest similarity. 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Meling-Lopez 45 63 75 Cover: Common color patterns 1n the Kelp Bass (Paralabrax clathratus). See page 49 for full color. Serials QH 1 S69 v.104 no.2 supplement ISSN 0038-3872 Po UTHERN CALIFORNIA, ACADEMY OF SCIENCES Volume 104 Supplement to Number 2 ABSTRACTS OF PAPERS A CORpoRATED 1 Os 2005 Annual Meeting Loyola Marymount University Los Angeles, California May 20-21, 2005 ~ a + fis ‘ { ~UU0 3 ! wiv. + i use | BCAS-A104(2, supplement 1—67) (2005) AUGUST 2005 Future SCAS Meetings 2006 — Pepperdine University Acknowlegements The Southern California Academy of Sciences wishes to acknowledge the following organizations and people for their support of the 2005 Annual Meeting. Sponsors MBC Applied Environmental Science Port of Los Angeles USC Wrigley Institute for Environmental Studies Aquatic Bioassay and Consulting Weston Solutions AMEC, Earth and Environmental Services Nautilus Pacific Ecorisk YSI Environmental Keane Biological Consulting Jonathan Baskin Daniel Guthrie In addition, special thanks to Drs. Jon Dorsey and Jim Landry, whose work arranging facilities at Loyola Marymount University was instrumental in our preparation for this meeting. This meeting was a Joint Meeting between the Southern California Academy of Sciences and The Society of Environmental Toxicology and Chemistry (SETAC). Phillip Markle of SETAC was instrumental in coordinating our efforts and organizing the SETAC portion of the meeting. SCAS Board Members and Officers Dr. John Dorsey, President Dr. Brad Blood, Vice President Dr. John Roberts, Secretary Dr. Daniel Guthrie, Editor and Treasurer Dr. Ralph G. Appy, Past President Robert Grove, Past President Dr. David G. Huckaby, Past President Dr. Daniel J. Pondella, I, Past President Board of Directors 2003-2006 2004—2007 2005-2008 Dr. M. James Allen Brad Blood Andrea Murray Dr. John H. Dorsey Dr. Donald G. Buth Dr. Jonathan N. Baskin Dr. Judith Lemus Robert S. Grove Dr. John Roberts Dr. Karen Martin Kathy Keene Gloria J. Takahashi Dr. Susan Yoder Dr. Edith Reed Dr. Philippa Drennan Junior Academy Board Members Bob Phalen Tetsuo Otsuki Richard and Martha Schwartz Dan Guthrie John Dorsey Gloria Takahashi, chair John Roberts Research Training Program Abstracts 125 to 144 represent the final product of the high school Research Training Program for 2004-05. The following students were selected to receive an honorary membership in the American Association for the Advancement of Sciences: Da Ium Im, Joon-Bok Lee, Julie A. Guerin and Carol Y. Suh. Based on their oral presentation and research paper, the following students were invited to present their work at the American Junior Association of Science meeting, held in conjuction with the A.A.A.S. meeting in February, 2005 in Washington, D.C.; Da lum Im, Joon-Bok Lee, Julie A. Guerin, Carol Y. Suh, Lisa Calfas, Daniel Chin, David Lluncor, Su Fey Ong, Geoffrey Woo, and Swati Yanamadala. We would like to acknowledge the Harbor Association of Industry and Commerce for generously supporting our Research Training Program. STUDENT AWARD WINNERS AT THE 2005 ANNUAL MEETING At the 2005 Annual Meeting, the following student papers and posters won awards. Awarded by the Southern California Academy of Sciences Best Posters: Physical Science: Ami Jenkins. Pasadena City College PRELIMINARY ANALYSIS OF A CAVE FAUNA FROM SAN QUIN- TIN, BAJA MEXICO. and Gregorio Pacheco-Ambriz. Pasadena City College CACHE OF FOSSIL REMAINS FOUND IN SAN QUINTIN, BAJA CALIFORNIA LOCATED WITHIN A BEACH CLIFF CAVE Ecology and Evolution: Andres Carillo. CSU Fullerton THE EFFECTS OF ARTICHOKE THISTLE (CYNARA CARDUNCU- LUS) DENSITY AND COASTAL SAGE SCRUB INFLUENCE ON PREDATION OF ARTIFICIAL NESTS. Best Poster, Molecular/physiological: P. Jensen. U. California Riverside INDIVIDUAL AND JOINT EFFECTS OF SELENATE AND METH- YLMERCURY ON A TERRESTRIAL INSECT DETRITIVORE. Best Papers Ecology/Evolution: R.A. Ellingson. CSU Los Angeles BORN AND RAISED IN SOUTHERN CALIFORNIA: DEVELOPMEN- TAL EVOLUTION AND CRYPTIC SPECIATION IN THE SEA SLUG GENUS ALDERIA. Ecology/Evolution: Tom Benson. CSU San Bernardino POPULATION GENETICS OF PYGMY NUTHATCHES IN SOUTH- ERN CALIFORNIA Fisheries: Andrew C. Davenport. San Diego State University POSITIVE INDIRECT EFFECTS OF REEF FISHES ON GIANT KELP PERFORMANCE Best Paper: Awarded by the American Institute of Fishery Research Biologists B.V. Ziegler. CSU Long Beach BEHAVIORAL THERMOREGUALTION OF THE LEOPARD SHARK (TRIAKIS SEMIFACIATA) IN THE NEARSHORE EMBAYMENTS OF SANTA CATALINA ISLAND, CALIFORNIA. 10 11 12 Southern California Academy of Sciences 2005 Session Schedule Friday, May 20, 2005 Location: Hilton Business Center, Room 100 Session: Wetland Restoration/Ecology Chair: Katherine Prickett 8:30 TOUR OF THE BALLONA FRESHWATER MARSH PROJECT. 10:00 SOUTHERN CALIFORNIA WETLAND RECOVERY PROJECT—A REGIONAL APPROACH TO WETLAND RECOVERY. Mary Small, State Coastal Conservancy. 10:20 BALLONA WETLANDS—-COMMUNITY BASED RESTORATION PLAN- NING. Mary Small, State Coastal Conservancy. 10:40—11:00 BREAK 11:00—11:30 Welcome, Student Grant Awards. 11:30—12:30 Plenary Talk: Dr. Brian Fagan: Fish on Friday: How the Catholic Doctrine of eating Fish on Friday changed History. 12:30—1:20 LUNCH BREAK [20 ORMOND BEACH: RESTORATION OF HISTORIC WETLANDS. Peter Brand. State Coastal Conservancy. 1:40 THE MALIBU LAGOON ENHANCEMENT PROJECT. C.S. Shuman. Heal the Bay, 3220 Nebraska Ave., Santa Monica, CA, 90404. 2:00 ECOSYSTEM RESTORATION AT TIJUANA ESTUARY, CALIFOR- NIA. Chris Nordby. Tierra Environmental Services, 9915 Businesspark Avenue, Suite C, San Diego, CA 92131. 2:20 ON A RESTORING WETLANDS GRASSROOTS LEVEL—NON-PROFITS AND WETLAND RESTORATION, D. Gibson. San Elijo Lagoon Conservancy Ex- ecutive Director/Principal Scientist, Encinitas, CA 92023. 2:40 THE JOURNEY FROM WETLANDS TO OIL FIELD AND BACK. Jim Trout. State Lands Commission. 3:00-3:20 BREAK 3:20 ENGINEERING OF THE BOLSA CHICA WETLANDS RESTORATION PRO- JECT. Chris Webb, Michael McCarthy, Moffatt & Nichol; Jack Fancher, U.S. Fish and Wildlife Service; and Keith Merkel, Merkel & Associates. 3:40 USING SPATIALLY-EXPLICIT MODELS TO PREDICT EELGRASS DISTRI- BUTION FOR RESOURCE MANAGEMENT AND RESTORATION. Robert Mooney. Merkel and Associates Inc. 4:00 EVALUATING THE SUCCESS OF WETLAND MITIGATION IN LOS AN- GELES AND VENTURA COUNTIES: ASSESSING PERMIT COMPLIANCE AND WET- LAND CONDITION. R.F. Ambrose and S.E Lee. Environmental Science and Engi- neering Program and Department of Environmental Health Sciences, University of Califor- nia, Los Angeles, CA 90095-1772. 4:20 DEVELOPMENT OF AN INTEGRATED REGIONAL ASSESSMENT PRO- GRAM FOR SOUTHERN CALIFORNIA WETLANDS. E.D. Stein, M. Sutula, and A.E. Fetscher. Southern California Coastal Water Research Project, 7171 Fenwick Lane, Westminster, CA 92683. 4:40 MONITORING PLAN FOR THE SAN DIEGUITO LAGOON RESTORATION PROJECT. Page, H. M., S. C. Schroeter, D. C. Reed, R. EK Ambrose, and M. A. Steele. Marine Science Institute, University of California, Santa Barbara, CA, 93106, Environmental Science and Engineering Program, University of California, Los Angeles, CA, 90095. Nw PROGRAM 3 13 14 15 16 17 18 19 20 21 Friday, May 20, 2005 Location: Hilton Business Center, Room 103 Session: Ecology of Nearshore Reefs Chair: Daniel Pondella, Occidental College and Bob Grove, S.C Edison 8:40 QUANTIFYING THE PERFORMANCE OF DIFFERENT REEF DESIGNS ON KELP BED FISH AND BENTHIC COMMUNITY DEVELOPMENT AT THE SAN CLE- MENTE EXPERIMENTAL ARTIFICIAL REEF. Dan Reed', Stephen Schroeter', David Huang!', Todd Anderson’, and Robert Grove’. 'Marine Science Institute, University of Cal- ifornia, Santa Barbara, CA 93106. reed@lifesci.ucsb.edu; 7Department of Biology, San Di- ego State University, San Diego CA 92182; *Southern California Edison Company, Rose- mead, CA 91770. grovers@sce.com. 9:00 EVALUATION OF KELP (MACROCYSTIS PYRIFERA (L.) C. AGARDH) KELP RESTORATION OFF TAJIGUAS, CALIFORNIA USING SCATTERED GRANIT- IG BOULDERS IN A SAND HABITAT. D. C. Barilotti, D. C. Lees and D. M. Schroe- der. Sea Foam Enterprises, San Diego CA 92107, seafoam @ mindspring.com; Littoral Eco- logical & Environmental Services, Leucadia, CA 92024, dennislees @earthlink.net; Marine Science Institute, UCSB, Santa Barbara 92106, schroed@lifesci.ucsb.edu. AU) “FLOATING” BEHAVIOR OF GRANITIC BOULDERS USED TO CON- STRUCT THE TAJIGUAS KELP HABITAT ON A SAND PLAIN AND COMPARISON OF THE DEVELOPING EPIBIOTIC INVERTEBRATE ASSEMBLAGE WITH NEARBY NATURAL REEF ASSEMBLAGES. Dennis C. Lees and D. Craig Barilotti. Littoral Ecological & Environmental Services, Leucadia, CA 92024 and Sea Foam Enterprises, San Diego, CA 92107. 9:40 COMPARISON OF REEF FISH ASSEMBLAGES AMONG NATURAL ROCK HABITATS AND THE CREATED TAJIGUAS KELP HABITAT IN THE SANTA BAR- BARA CHANNEL. D. M. Schroeder and D. C. Barilotti. Marine Science Institute, Uni- versity of California, Santa Barbara, CA 93106, schroed@lifesci.ucsb.edu; and Sea Foam Enterprises, 4369 Osprey Street San Diego CA 92107. 10:00 POSITIVE INDIRECT EFFECTS OF REEF FISHES ON GIANT KELP PER- FORMANCE. Davenport, Andrew C. San Diego State University. 10:20 MARINE RESERVE DESIGN: DETERMINING AN OPTIMAL SIZE AND LO- CATION. P.E. Parnell’, Paul K. Dayton', and Cleridy Lennert-Cody’. 'Scripps Institu- tion of Oceanography, UCSD, La Jolla, CA 92093-0227; *Inter-American Tropical Tuna Commission, 8604 La Jolla Shores Drive, La Jolla, CA 92037-1508. 10:40—11:00 BREAK 11:00—11:30 Welcome, Student Grant Awards. 11:30—12:30 Plenary Talk: Dr. Brian Fagan: Fish on Friday: How the Catholic Doctrine of eating Fish on Friday changed History. 12:30—1:40 LUNCH BREAK 1:40 BEHAVIORAL THERMOREGUALTION OF THE LEOPARD SHARK (TRIAKIS SEMIFACIATA) IN THE NEARSHORE EMBAYMENTS OF SANTA CAT- ALINA ISLAND, CALIFORNIA. B.V. Ziegler, California State University Long Beach, Department of Biological Sciences, Long Beach, CA, 90840-3702. 2:00 MOVEMENT PATTERNS AND HABITAT USE OF OCEAN WHITEFISH (BRANCHIOSTEGIDAE) IN A SANTA CATALINA ISLAND MARINE RE- SERVE. Bellquist, L.F.', C.G. Lowe’, and J.E. Caselle*. '’California State University Long Beach, Department of Biological Sciences, Long Beach, CA 90840; *Marine Science Institute, University of California Santa Barbara, Santa Barbara, CA 93106. 2:20 THE FISH ASSEMBLAGE S OF AN ARTIFICIAL AND NATURAL REEF IN THE HORSESHOE KELP. J.T. Froeschke', B.M. Haggin’, D.J. Pondella' and L.J. Allen. 'Vantuna Research Group, Occidental College, Department of Biology, Los Angeles, CA, 90041; *Nearshore Marine Fish Research Program, California State University, Northridge, Department of Biology, Northridge CA, 91330. ; 22 23 24 25 27 28 29 30 31 32 M M SOUTHERN CALIFORNIA ACADEMY OF SCIENCES 2:40 EFFECTS ON NEARSHORE ROCKY REEFS FOLLOWING THE REGIONAL BEACH SAND PROJECT. L. Honma', B. Snyder’, and R. Rundle*’. 'Merkel & Asso- ciates, 5434 Ruffin Rd, San Diego, CA 92123; 7AMEC Earth & Environmental, 5510 More- house Dr., San Diego, CA 92121; *San Diego Association of Governments (SANDAG), 401 B Street Suite 800, San Diego, CA 92101. 3:00 BREAK 3:20 EVALUATION OF EELGRASS MITIGATION AND FISHERY ENHANCE- MENT STRUCTURES IN SAN DIEGO BAY, CALIFORNIA. D. J. Pondella, II’, L. G. Allen’, M. T. Craig* and B. Gintert*t. 'Vantuna Research Group, Department of Biology, Occidental College, Los Angeles, CA 90041; ?7Department of Biology, California State Uni- versity, Northridge, CA 91330-8303; *Scripps Institution of Oceanography, La Jolla, CA 92093-0208; *Rosenstiel School of Marine and Atmospheric Science, Marine Biology and Fisheries Division, Miami, FL 33149. 3:40 LESSONS LEARNED, A HALF-CENTURY OF GIANT KELP RESTORATION IN SOUTHERN CALIFORNIA. Mike Curtis. MBC Applied Environmental Sciences. 4:00 GIANT KELP RESTORATION AND MONITORING IN SANTA MONICA BAY. T. Ford. Santa Monica Baykeeper, PO. Box 10096, Marina del Rey, CA 90295. Friday, May 20, 2005 Location: Hilton Business Center, Room 107 Session: Contributed Papers Chair: Don Buth, UCLA 9:00 COMPARISON OF DIGESTIVE ENZYME ACTIVITIES IN TUNAS AND THEIR ECTOTHERMIC RELATIVES. D. L. Neumann and K. Dickson. California State University, Fullerton, Department of Biology, Fullerton, CA, 92831. 9;20 STRUCTURAL COMPLEXITY OF SEAGRASS INFLUENCES PATTERNS OF RECRUITMENT OF FISHES IN SAN DIEGO BAY. Lipski, D.M. San Diego State University, San Diego, CA, 92182. 9:40 TRANSITIVITY AND SONG PREFERENCES IN THE HOUSE CRICKET, ACHETA DOMESTICUS. Sean E. Walker! and J. Andrew Roberts*. 'Department of Biological Science, California State University Fullerton; 7Department of Evolution, Ecol- ogy, and Organismal Biology, The Ohio State University, Newark. 9:40 ACOUSTIC TRACKING AND MONITORING OF CULTURED JUVENILE WHITE SEABASS RELEASED INTO SOUTHERN CALIFORNIA EMBAY- MENTS. M. A. Shane', M. A. Drawbridge’, and H. C. Simonds’. 'Hubbs-SeaWorld Research Institute, 2595 Ingraham Street, San Diego, CA, 92109; *San Diego State Uni- versity Foundation, 5250 Campanile Drive, San Diego, CA 92182. 10:20 LACTATE PROCESSING IN ENDOTHERMIC AND ECTOTHERMIC SHARKS. J.M. Backey and K.A. Dickson. California State University, Department of Biological Science, Fullerton, CA, 92831. Friday, May 20, 2005 Location: Hilton Business Center, Room 107 Session: Archaeology and Paleontology of Southern California Chair: Andrea P. Murray, California State University, Fullerton 1:40 LATE PREHISTORIC CERAMIC PRODUCTION IN THE UPPER MOJAVE RIVER REGION, SAN BERNADINO COUNTY, CALIFORNIA. B. Travis. Depart- ment of Anthropology, California State University, Fullerton, CA 92831. 2:00 = ARCHAEOFAUNAL RESEARCH AT LATE HOLOCENE PREHISTORIC SITES ON SAN NICOLAS ISLAND: RECENT EXCAVATIONS AND EXPERIMENTAL STUDIES. Steven R. James and James R. Wallace. Department of Anthropology, Cali- fornia State University at Fullerton, PO. Box 6846, Fullerton, CA 92834-6846. PROGRAM 5 33 34 35 36 37 38 39 40 41 42 44 45 220 ARCHAEOLOGY AT THE HARVARD HILL SITE, SAN BERNARDINO COUNTY, CALIFORNIA. J.A. McKenna. McKenna et al., Whittier, CA 90601-3724. 2:40 TWO RITUAL CACHES FROM CA-ORA-950: A WINDOW ONTO THE SYMBOLOGY OF COGGED STONES. H. C. Koerper. Cypress College, Cypress, CA 90630. 3:00 BREAK 3220 PREHISTORIC ADAPTATIONS TO COASTAL WETLANDS: AN 8,000 YEAR VIEW FROM SANTA MONICA BAY, WEST LOS ANGELES. John G. Douglass, Jef- frey H. Altschul, Richard Ciolek-Torrello, Benjamin R. Vargas, and Donn R. Grenda. Sta- tistical Research, Inc. 21 West Stuart Ave Redlands, CA 92373. 3:40 OPTIMAL RESOURCE PRODUCTION: A MODEL OF CHUMASH IMPACT ON THE ENVIRONMENT IN THE SANTA BARBARA CHANNEL AREA. Edgar H. Huerta. Department of Anthropology, California State University, Fullerton, 800 N. State College Blvd, Fullerton, CA 92831. 4:00 “JUNE GLOOM” AND “TULE FOG”: CONSIDERATIONS OF THE IMPOR- TANCE OF CLOUD MOISTURE FOR PREHISPANIC SETTLEMENT AND SUBSIS- TENCE STRATEGIES IN SOUTHERN CALIFORNIA. Frederick W. Lange, PhD. LSA Associates—Riverside Office. 4:20 PALEOCLIMATE AND VEGETATION RECORD IN THE LATE PLEISTO- CENE PALOS VERDES FORMATION (“OLDER ALLUVIUM’’) IN THE SAN FERNAN- DO VALLEY, SOUTHERN CALIFORNIA. L.H. Fisk. PaleoResource Consultants, 5325 Elkhorn Boulevard, #294, Sacramento, CA 95842. 4:40 REVISED CORRELATION AND AGE ASSIGNMENTS OF FOSSIL LAND MAMMAL ASSEMBLAGES OF LATE HEMINGFORDIAN TO EARLIEST HEMPHIL- LIAN (EARLY MIDDLE TO EARLY LATE MIOCENE) AGE IN CALIFORNIA, NE- BRASKA, AND TEXAS, BASED ON OCCURRENCES OF TICHOLEPTINE OREO- DONTS (MAMMALIA, ARTIODACTYLA, OREODONTIDAE, TICHOLEPTINAE) AND OTHER LAND MAMMAL TAXA. E.B. Lander. Paleo Environmental Associ- ates, Inc., 2248 Winrock Avenue, Altadena, CA, 91001-3205. Friday, May 20, 2005 Location: Hilton Business Center, Room 300 Time: 5-7 p.m. Session: Poster Session and Social CACHE OF FOSSIL REMAINS FOUND IN SAN QUINTIN, BAJA CALIFORNIA LO- CATED WITHIN A BEACH CLIFF CAVE. G. Pacheco-Ambriz. Baja California Inde- pendent Research Project, Pasadena City College, Department of Natural Science, Pasadena, CAS9I1003; ADSORPTION OF SYNTHETIC PYRETHROIDS ON SEDIMENT. S. Bondarenko, S. Qin and J. Gan. Department of Environmental Sciences, University of California, Riv- enside-JEAG92 57 SURVEY FOR SYNTHETIC PYRETHROIDS WITHIN THE SAN DIEGO/NEWPORT BAY WATERSHED. R.L. Budd, S. Bondarenko, and J. Gan. University of California at Riverside, Riverside, CA 92521. THE EFFECT OF FEMALE CHEMICAL CUES ON THE AGGRESSIVE BEHAVIOR OF MALE CRICKETS, ACHETA DOMESTICUS. Leslie J. Buena and Sean E. Walker. Department of Biological Science, California State University, Fullerton. Fullerton, Ca 92831. THE EFFECTS OF ARTICHOKE THISTLE (CYVARA CARDUNCULUS) DENSITY AND COASTAL SAGE SCRUB INFLUENCE ON PREDATION OF ARTIFICIAL NESTS. Andres Carrillo and Leslie Buena. Department of Biological Science, California State University, Fullerton. SEWAGE IS AN UNLIKELY SOURCE OF FECAL INDICATOR BACTERIA IN THE LOW- ER SANTA ANA RIVER WATERSHED. D.L. Young, J. A. Noblet’, E. Y. Zeng' and S. Ensari*. ‘Southern California Coastal Water Research Project, Westminster, California; ?California State University, San Bernardino, California; and *University of California, Irvine, California. 6 46 47 E 48 50a E 50b M 53 55 56 57 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES DESCRIPTION OF FIELD-COLLECTED LARVAE OF TWO NATIVE FRESHWATER SOUTHERN CALIFORNIA FISHES, CATOSTOMUS SANTAANAE AND GILA OR- CUTTI. Richard F. Feeney. Natural History Museum of Los Angeles County, 900 Ex- position Blvd.,Los Angeles, CA 90007; and Camm C. Swift. ENTRIX, Inc., 2140 Eastman Ave. Suite 200, Ventura, CA 93003. AXIAL SPLITTING OF SHRUBS IN WET AND DRY ENVIRONMENTS. C. Goed- hart, G. Pongetti, S. Espino, J. Schenk. California State University, Fullerton, Department of Biology. EVALUATION OF METHODS FOR DETERMINING CHRONIC TOXICITY IN MA- RINE SEDIMENTS. D. Greenstein', S. Bay', B. Anderson’, B. Phillips’, G. T. Chandler’, D. Farrart, A. H. Ringwood’, and C. Keppler®. ‘Southern California Coastal Water Research Project, Westminster CA; ?University of California Davis, Monterey, CA; *University of South Carolina, Columbia, SC; *US Army Engineer Research and Development Center, Vicksburg, MS; °University of North Carolina—Charlotte, Charlotte, NC; °Marine Resources Research Institute, Charleston, SC. LACK OF GENDER-BIASED MICROSITE PATTERNS IN SALIX LASIOLE- PIS. Shannon Harsh and Allison Roth, Dustin Taylor and Cheryl Swift. Whittier Col- lege, Department of Biology, Whittier, CA 90608. MORPHOLOGY AND MOLECULAR PHYLOGENY OF EGREGIA MENZIE- SIT. Henkel, S.K., G.E. Hofmann, and A.C Whitmer. Marine Science Program, Depart- ment of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara 93106. BIOAVAILABILITY OF PERMETHRIN IN SEDIMENTS AND ESTIMATED WITH SOLID PHASE MICROEXTRACTION (SPME). W. Hunter, W. Yang, and J. Gan. University of California, Riverside, Riverside, CA 92521. PRELIMINARY ANALYSIS OF A CAVE FAUNA FROM SAN QUINTIN, BAJA MEXI- CO. A,J. Jenkins. Baja California Independent Research Project, Pasadena City College, Department of Natural Science, Pasadena, CA 91106. BOLUS REBOUND KINEMATICS DURING ENGULFMENT FEEDING IN THE ROR- QUAL WHALES. B.W. Kot. Department of Ecology and Evolutionary Biology, UCLA, Los Angeles, CA 90095. THE GREATEST GRUNION HUNT IN 50 YEARS: CALIFORNIA GRUNION SIGHT- INGS ACROSS THE SEASON AND ALONG THE COAST IN 2004. K. Martin, B. Cupp, and P. Johnson. Pepperdine University, Malibu, CA 90263-4321. INTERACTIONS OF NEARSHORE FISH ASSEMBLAGES AND NET-PEN MARICUL- TURE EFFORTS ON SANTA CATALINA ISLAND, CALIFORNIA. C.T. Oakes and D.J. Pondella, If. Vantuna Research Group, Occidental College, Department of Biology, Los Angeles, CA 90041. A COMPARISON OF PREVALENCE AND MEAN INTENSITY OF THE ECTOPARA- SITE ELTHUSA CALIFORNICA IN SHINER SURFPERCH (CYMATOGASTER AG- GREGATA) OF TOMALES AND BODEGA BAYS. Pritchard, Justin, Will Madrid, and Nick Weston-Swan. UCLA, Department of Ecology and Evolutionary Biology, Los Angeles, CA 90024. ANALYSIS OF HISTORICAL CHLORDANE LEVELS IN SAN DIEGO AND MISSION BAY IN COMPARISON TO THE THRESHOLD LEVEL OF TOXICITY TO THE AM- PHIPOD, EOHAUSTORIUS ESTUARIUS. Y. Rodriguez'’, J. Rudolph’, C. Stransky’. 'San Diego State University; "Nautilus Environmental, San Diego, CA. SEASONAL BACTERIAL CONCENTRATIONS IN THE LONG BEACH/LOS ANGELES HARBOR COMPLEX; YEAR TWO OF A FIVE YEAR STUDY. K.A Snow, K.E. Flah- erty, Y.J. Ralph, C.V. Wolfe, K. Kull and R.E. Pieper. Southern California Marine Institute, Terminal Island, CA 90731. INDEPENDENT AND JOINT TOXICITY OF PERCHLORATE AND HEXAVALENT CHROMIUM TO LARVAL MOSQUITOES. M.A. Sorensen and J.T. Trumble. Univer- sity of California, Riverside, Riverside, CA 92521. VARIATION OF JOSHUA TREE MORPHOLOGY AMONG POPULATIONS IN THE EASTERN MOJAVE DESERT. Tracy Valentovich and Darren Sandquist. California State University, Fullerton. Fullerton, CA, 92831. PROGRAM a 60 61 62 63 64 65 66 67 68 69 71 72 73 M ENDOCRINE DISRUPTION IN SOUTHERN COASTAL CALIFORNIA FLAT- FISH. D.E. Vidal', J. Armstrong’, M. Baker’, J. Gully*, M. Irwin’, K.M. Kelley®, D. Montagne’, J. Reyes®, D. Schlenk®, S.M. Bay!'. 'Southern California Coastal Water Research Project, Westminster, CA; 7Orange County Sanitation District, Fountain Valley, CA; ?Uni- versity of California at San Diego, La Jolla, CA; “Los Angeles County Sanitation District, Whittier, CA; *University of California at Riverside, Riverside, CA; °California State Uni- versity at Long Beach, Long Beach, CA. HPLC COLUMNS WITH MODIFIED MONOSACCHARIDE DERIVATIVES AS CHI- RAL SELECTOR. L. Wenjian' and L. Tingyu’. ' University of California, Riverside. CA. ? Mississippi State University, Mississippi State, MS. BIOAVAILABILITY OF SYNTHETIC PYRETHROIDS IN SURFACE WATER. W. Yang, W. Hunter, and J. Gan. University of California, Riverside, Riverside, CA 92521. STRAIN RELATEDNESS OF CANDIDA IN HUMANS: A URINARY PATHOGEN OR COLONIZER? (PHASE 1). Joon-Bok Lee. California Academy of Math and Science and Division of Infectious Diseases, Los Angeles County Harbor-UCLA Medical Center, 1000 W. Carson Street, Torrance, California 90502. EFFECTS OF PHOSPHATE ON THE BIOLOGICAL PROCESSES OF TRICHODES- MIUM. S.F. Ong', J. Sohm’, and D. Capone’. 'California Academy of Mathematics and Science, Carson, CA; *Wrigley Institute of Environmental Biology, University of Southern California, Department of Biological Sciences, Los Angeles, CA. DETERMINATION OF BACTERIAL AND POLLUTANT FLOWS IN COASTAL ES- TUARIES OF SOUTHERN CALIFORNIA. S. Yanamadala and J. Dorsey. Chadwick School and Loyola Marymount University, Department of Natural Sciences, Los Angeles, CA, 90045. NEAR REAL-TIME DETECTION OF ESCHERICHIA COLI FOR MONITORING BEACH WATER QUALITY. J. Jay. University of California, Los Angeles, Los An- geles, California. INDIVIDUAL AND JOINT EFFECTS OF SELENATE AND METHYLMERCURY ON A TERRESTRIAL INSECT DETRITIVORE. P.D. Jensen and J.T. Trumble, University of California, Riverside, Riverside, CA. HEAVY METALS IN THE CLAM MEGAPITARIA SQUALIDA FROM APPARENTLY POLLUTION-FREE ZONES IN BAJA CALIFORNIA, MEXICO: CONSIDERATIONS FOR HUMAN HEALTH EFFECTS. L. Méndez, E. Palacios, B. Acosta, P Monsalvo- Spencer, and S.C. Gardner. Centro de Investigaciones Biologicas del Noroeste, S.C., La Paz, Baja California Sur, Mexico. SUSCEPTIBILITY OF OXIDATIVELY CROSSLINKED B-AMYLOID PEPTIDES TO IN- SULIN DEGRADING ENZYME. J. Young. Alhambra High School and USC Keck School of Medicine, School of Pharmacy, Department of Pharmaceutical Science, Los An- geles, CA, 90089. Saturday, May 21, 2005 Location: Hilton Business Center, Rm. 103 Session: Fire Ecology Chair: Ruth Wilson 8:50 INTRODUCTION, RUTH WILSON 9:00 THE HISTORY OF WILDLAND FIRES IN AMERICA. RJ. Vogl. Biology Department, California State University, Los Angeles 90032. 920 ECONOMIC IMPACT OF WILDLAND FIRES. Armando Gonzalez-Caban. USDA Forest Service, Pacific Southwest Research Station, Forest Fire Laboratory, 4955 Canyon Crest Drive, Riverside, California 92507. 9:40 POST-FIRE EROSION IN THE SAN GABRIEL MOUNTAINS. P.M. Wohl- gemuth. USDA Forest Service, Pacific Southwest Research Station, 4955 Canyon Crest Drive, Riverside, CA 92507. 74 75 76 77 78 79 80 81 82 83 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES 10:00 NEW TRICKS ON THE OLD FIRE. Fujioka, Francis M. USDA Forest Ser- vice, Forest Fire Laboratory, 4955 Canyon Crest Drive, Riverside, CA 92507. 10:20 STRATEGIC FIRE MAPPING—TECHNOLOGY DEVELOPMENT FOR AIR- BORNE REMOTE SENSING OF WILDLAND FIRES. Philip J. Riggan. USDA Forest Service, PSW Research Station, 4955 Canyon Crest Drive Riverside, CA 92507. 10:40 BREAK 11:00 Plenary Talk: Dr. James Powell: The Grand Canyon: Solving Earth’s Grandest Puzzle. 12:00—1:20 LUNCH BREAK Saturday, May 21, 2005 Location: Hilton Business Center, Rm. 103 Session: Fire Ecology (Continued) Chair: M. Narog 120 CHANGES IN SPATIAL DISTRIBUTION AND ABUNDANCE OF BIRDS IN RELATION TO FIRE AND DROUGHT-INDUCED VEGETATION MORTALITY IN SOUTHERN CALIFORNIA. Rechel, Jennifer L. USDA Forest Service, Pacific South- west Research Station, Forest Fire Laboratory, Riverside, CA. USA 92507-6071. 1:40 THE CONTRIBUTION OF FOREST INSECTS AND PATHOGENS TO TREE MORTALITY IN SOUTHERN CALIFORNIA MONTANE FORESTS. L.D. Merrill. USDA Forest Service, 4955 Canyon Crest Drive, Riverside, CA 92507. 2:00 WILDFIRE AFFECTS SOUTHERN CALIFORNIA RIPARIAN HABI- TAT. M. G. Narog, C. J. Sclafani, and J. L. Beyers. USDA Forest Service, Pacific Southwest Research Station, Riverside, CA. 2:20 SAN DIEGO FIRE RECOVERY NETWORK: WORKING AND LEARNING TOGETHER. M. McFlhinney, San Diego Fire Recovery Network; and A.S. Fege, San Diego Natural History Museum, Box 121390, San Diego, CA 92112. 2:40 Concluding Panel; Marcia Narog. Saturday, May 21, 2005 Location: Hilton Business Center, Rm. 107 Session: Avian Research in Southern California Chair: Kathy Keane, Keane Biological 8:40 HOW ISLAND SCRUB-JAYS ATTAIN BREEDING STATUS IN LIMITED HABITAT. K. A. Corey, C.T. Collins. U.S. Fish and Wildlife Service, Carlsbad Field Office, Carlsbad, CA 92009; Department of Biological Sciences, California State University, Long Beach, CA 90840. 9:00 POPULATION GENETICS OF PYGMY NUTHATCHES IN SOUTHERN CAL- IFORNIA. T. A. Benson and A. E. Metcalf. Department of Biology, California State University, 5500 University Parkway, San Bernardino, CA 92407. 9:20 SEASONAL AND INTERANNUAL MOVEMENTS OF SALTON SEA- HATCHED BLACK SKIMMERS (RYNCHOPS NIGER). K. C. Molina and K. L. Gar- rett, Natural History Museum of Los Angeles County, Los Angeles, CA 90007; C. T. Collins. California State University, Long Beach, CA 90840. 9:40 OVER-WINTERING BEHAVIOR OF BLACK SKIMMERS IN SOUTHERN CALIFORNIA: SITTERS AND WANDERERS. C. T. Collins, K. Molina and K. L. Garrett. Department of Biological Sciences, California State University, Long Beach, CA 90840; and Natural History Museum of Los Angeles County, 900 Exposition Blvd., Los Angeles, CA 90007. PROGRAM 9 84 85 86 87 88 89 90 91 92 93 94 95 10:00 AVIAN EXTIRPATION AND COLONIZATION IN THE BALLONA VALLEY, LOS ANGELES COUNTY, CALIFORNIA. Daniel S. Cooper. Audubon California, 11340 W. Olympic Blvd., Suite 209, Los Angeles, CA 90064. 10:20 CHANGES IN BIRD SPECIES DIVERSITY FOLLOWING A SALTMARSH RESTORATION PROJECT AT BATIQUITOS LAGOON. K.M. Keane. Keane Bio- logical Consulting, 2892 N. Bellflower Blvd., Suite 480, Long Beach, CA 90815. 10:40—11:00 BREAK 11:00—12:00 Plenary Talk: Dr. James Powell: The Grand Canyon: Solving Earth’s Grandest Puzzle. 12:00—1:20 LUNCH BREAK Saturday, May 21, 2005 Location: Hilton Business Center, Rm. 107 Session: What’s the Status of our Special-Status Bird Species? Chair: Kathy Keane, Keane Biological E20 SPECIAL STATUS BIRDS OF THE WHITTIER NARROWS BASIN, LOS AN- GELES COUNTY. M.C. Long. Los Angeles County Natural Areas, 1750 N. Altadena Dr., Pasadena, CA 91107. 1:40 POPULATION STATUS OF ROYAL TERNS IN SOUTHERN CALIFOR- NIA. C. T. Collins. Department of Biological Sciences, California State University, Long Beach, CA 90840. 2:00 POPULATION STATUS OF THE CALIFORNIA LEAST TERN. K.M. Keane. Keane Biological Consulting, 2892 N. Bellflower Blvd., Suite 480, Long Beach, CA 90815. 220 LEAST BELL’S VIREO IN THE SANTA ANA RIVER WATERSHED. R. Zembal. Orange County Water District, 10500 Ellis Avenue, Fountain Valley, CA 92708. 2:40 POPULATION STATUS OF THE WESTERN GULL-BILLED TERN (STERNA NILOTICA VANROSSEMD IN NORTH AMERICA. K. C. Molina. Ornithology, Nat- ural History Museum of Los Angeles County, 900 Exposition Blvd., Los Angeles, CA 90007. 3:00-3:20 BREAK 320 POPULATION STATUS OF LIGHT-FOOTED CLAPPER RAIL. R. Zem- bal, S.M. Hoffman, and J. Konecny. Department of Biological Sciences, CA State Univer- sity, Long Beach 90840. 3:40 THE STATUS OF WESTERN SNOWY PLOVERS IN COASTAL SOUTHERN CALIFORNIA. Kevin B. Clark. U.S. Fish and Wildlife Service, Carlsbad, CA 92009. 4:00 DIETARY RESPONSE OF THE ELEGANT TERN (STERNA ELEGANS) TO CHANGING OCEAN CONDITIONS AND PREY POPULATIONS IN SOUTHERN CAL- IFORNIA. K. L. Connell and M. H. Horn. California State University, Fullerton, De- partment of Biological Science, Fullerton, CA 92834. Saturday, May 21, 2005 Location: Hilton Business Center, Rm. 109 Session: Contributed Papers Chair: Jon Baskin 8:40 GAS EXCHANGE RESPONSES TO PULSE RAIN EVENTS BY A NATIVE HAWAITIAN DRY FOREST VINE AND THE EFFECT OF INTERACTION WITH NON- NATIVE GRASSES. P.A. Koenig and D.R. Sandquist. Department of Biological Sci- ence, California State University, Fullerton, CA 92831. 9:00 BORN AND RAISED IN SOUTHERN CALIFORNIA: DEVELOPMENTAL EVOLUTION AND CRYPTIC SPECIATION IN THE SEA SLUG GENUS ALDER- IA. R.A. Ellingson and P.J. Krug. California State University Los Angeles, Department of Biological Sciences, Los Angeles, CA 90032. 10 96 97, 98 99 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES EF 7 9220 SHALLOW SURF RIDERS: SMALL-SCALE LARVAL DISTRIBUTION IN ES- TUARINE WATERS. D.A. Willette and PJ. Krug. California State University, Los An- geles, Department of Biological Sciences, Los Angeles, CA 90032. 9:40 RAPID ASSESSMENT OF TERRESTRIAL AND MARINE HABITATS USING TWO NOVEL METHODS FOR ESTIMATING THE DENSITIES AND DISTRIBUTIONS OF ORGANISMS. G.K. Nishiyama and C.A. Kay. College of the Canyons, Department of Biology, Santa Clarita, CA 91355. 10:00 ON SOUTHERN CALIFORNIA ABYSSAL ECHINODERMS. K.D. Trego. Nautilus Oceanic Institute, La Jolla, CA 92037. 10:20 THE DEEP SEA HOLOTHURIAN SCOTOPLANES GLOBOSA OFF SOUTH- ERN CALIFORNIA. K.D. Trego. Nautilus Oceanic Institute, La Jolla, CA 92037. Saturday, May 21, 2005 Location: Hilton Business Center, Rm. 100 Session: SETAC Plenary Session; “New Frontiers in Environmental Chemistry”’ 100 101 102 103 104 105 106 Chair: Lan Wiborg, City of San Diego 8:40 TOOLS FOR TRACKING THE FATE OF WASTEWATER-DERIVED CON- TAMINANTS IN EFFLUENT-DOMINATED WATERS. David L. Sedlak. University of California, Berkeley, CA. 920 CONTAMINANT FATE AND SOURCE TRACKING USING CHIRAL AND STABLE ISOTOPE ANALYSIS. Kieth Maruya, K.A.* and Peng, J.. SCCWRP, West- minster, CA; Zeng, E.Y., Chinese Academy of Sciences, Guangzhou, China. 10:00 CHEMICAL METHODS FOR MEASURING BIOAVAILABILITY. Jay Gan. Department of Environmental Science, University of California, Riverside. 10:40—11:00 BREAK 11:00—12:00 Plenary Talk: Dr. James Powell: The Grand Canyon: Solving Earth’s Grandest Puzzle. 12:00—1:20 LUNCH BREAK Saturday, May 21, 2005 Location: Hilton Business Center, Rm. 100 Session: Marine Pollution: Contaminants, Bioaccumulation and Effects on Marine Organisms (Jointly sponsored by SCAS and SETAC) Chair: Jim Allen and Ken Schiff, (SCCWRP) 1:20 WATER QUALITY ON SWIMMING BEACHES: NEW DIRECTIONS FOR THE EUROPEAN UNION. A. Staines. Urban Water Technology Centre, University of Abertay Dundee, Bell St, Dundee, DDI 1HG, Scotland, United Kingdom. 1:40 CONTAMINANT TRENDS IN THE SOUTHERN CALIFORNIA BIGHT: A MUSSEL WATCH UPDATE. A. J. Mearns and G. Lauenstein. National Ocean Service, National Oceanic and Atmospheric Administration, Seattle, WA and Silver Spring, MD. 2:00 A COMPARISON OF TRACE METAL CONCENTRATIONS IN DEEP OFF- SHORE AND NEARSHORE SEAWATER FROM SOUTHERN CALIFOR- NIA. Richard Gossett. CRG Marine Laboratories, 2020 Del Amo Blvd, Torrance, CA 90501. 2:20 = HEAVY METAL ACCUMULATION IN SEA TURTLES FROM THE BAJA CALIFORNIA PENINSULA, MEXICO. S.C. Gardner, S.L. Fitzgerald, B. Acosta Var- gas L. Méndez Rodriguez. Centro de Investigaciones Bioldgicas del Noroeste, S.C., La Paz, Baja California Sur, Mexico. PROGRAM 11 107 108 110 111 109 112 113 114 115 116 2:40 PROBING METAL-LIGAND INTERACTIONS USING STABLE ISOTOPI- CALLY LABELED PROTEINS AND DIRECTLY COUPLED HPLC-ICP-MS. Se be Mason, T.M. Potter, J. Webster, and R.E Meraz. Department of Biological Sciences and Institute for Integrated Research in Materials, Environments and Society, California State University, Long Beach, 90840, USA. 3:00 BREAK 32.0 STRATIFYING BAY AND ESTUARY HABITATS OF THE WEST COAST OF THE CONTIGUOUS USA: A STEP TOWARD REGIONAL INDICATORS OF BENTHIC COMMUNITY CONDITION. J.A. Ranasinghe', K.I. Welch’, P.N. Slattery’, D.E. Mon- tagne*, D.D. Huff, H. Lee, II®, J.L. Hyland’, B. Thompson’, S.B. Weisberg!, J.M. Oakden’. 'SCCWRP, Westminster, CA; Washington State Department of Ecology, Olympia, WA; 3Moss Landing Marine Laboratory, Moss Landing, CA; *County Sanitation Districts of Los Angeles County, Whittier, CA; °Oregon Dept. of Environmental Quality, Portland, OR; °US EPA, Western Ecology Division, Newport, OR; 7NOAA, NOS, Charleston, SC; *San Fran- cisco Estuary Institute, Oakland, CA. 3:40 DISRUPTION OF THE STRESS RESPONSE ENDOCRINE SYSTEM IN MA- RINE FISHES IN THE SOUTHERN CALIFORNIA BIGHT. Kevin M. Kelley, Jesus A. Reyes, Kathy Sak, Shari Smolko, and Jeffery L. Armstrong*. Department of Biological Sciences, California State University, Long Beach, Long Beach, CA 90840; *“Orange County Sanitation District (OCSD), Fountain Valley, CA, 92708. 4:00 GROWTH ENDOCRINE DISRUPTION IN SOUTHERN CALIFORNIA MA- RINE FLATFISH. Jesus A. Reyes and Kevin M. Kelley. Department of Biological Sci- ences, California State University, Long Beach, Long Beach, CA 90840. 4:20 INFESTATION OF PARASITIC COPEPODS AND THE POTENTIAL OF STRESS ON HOST FISHES. Julianne E. Kalman. University of California Los Angeles, Department of Ecology and Evolutionary Biology, Los Angeles, CA 90095 and Orange County Sanitation District, Environmental Assessment Division, Fountain Valley, CA 92708. 4:40 BIOACCUMULATION OF CONTAMINANTS IN RECREATIONAL AND FORAGE FISHES IN NEWPORT BAY, CALIFORNIA IN 2000-2002. M. J. Allen', D. W. Diehl', and E. Y. Zeng’. 'Southern California Coastal Water Research Project, Westmin- ster, CA 92683; *State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, P.O. Box 1131, Guangzhou 51064, China. Saturday, May 21, 2005 Location: Business Center, Rm. 109 Session: Environmental Toxicology and Chemistry (SETAC) Chair: Jeff Armstrong, Orange County Sanitation District 1:20 OXIDATION OF SELENOMETHIONINE BY FLAVIN-CONTAINING MONO- OXYGENASES (FMOS). D. Shi and D. Schlenk. University of California, Riverside, Riversides€A09752 1 1:40 ENANTIOSELECTIVITY IN PYRETHROID DEGRADATION IN SOIL. S. Qin, M. G. Nillos, and J. Gan. University of California, Riverside, Riverside, CA 92521. 2:00 ENANTIOMERIC SULFOXIDATION OF THE ORGANOPHOSPHATE PES- TICIDE FENTHION IN FISH. O. Bawardi', B. Furnes, J. Rimoldi?, D. Schlenk'. ! University of California Riverside, Riverside, CA 92521; ’The University of Mississippi, University, MS 38677. 220 LINKING BIOMARKER RESPONSES AND PHYSIOLOGICAL STRESS TO GROWTH IMPAIRMENT OF CADMIUM-EXPOSED LARVAL TOPSMELT. W. Rose. Ro wNisbet.. & Green; S. Norms, TE Ban=, E) Smith® 'G. Cherr’, and S. Anderson’. 'Bodega Marine Laboratory, University of California Davis, Bodega Bay, CA; Ecology, Evolution, and Marine Biology, University of California Santa Barbara, Santa Barbara, CA; 3Civil & Environmental Engineering, “Land, Air, and Water Resources, University of Cali- fornia Davis, Davis, CA; °Chemistry, University of Louisville, Louisville, KY. IZ SOUTHERN CALIFORNIA ACADEMY OF SCIENCES 117 2:40 ARTHROGRYPOSIS FOLLOWING ACRYLAMIDE EXPOSURE. j.G. Dahlgren’, R.T. Schmidt’, and H.S. Takhar’. 'UCLA School of Medicine, Los Angeles, CA; *"James Dahlgren Medical, Los Angeles, CA. 3:00 BREAK 118 M = 3:20 EXPRESSION AND CHARACTERIZATION OF CHANNEL CATFISH CYP 2X1. S. Mosadeghi, B. Furnes, C. Wong, D. Schlenk. University of California, Riverside, Riverside, CA 92521. 119 3:40 IDENTIFYING ALUM AS A TOXICANT IN WHOLE EFFLUENT TOXICITY TESTS. K. Rinald, P. J. Markle, C. Barton, E.X. DeHollan, and J.P. Bottomley. County Sanitation Districts of Los Angeles, Whittier, CA 90601. Saturday, May 21, 2005 Location: Hilton Business Center, Rm. 118 Session: Application of Freshwater Bioassessments in Southern California (Sponsored by SETAC) Chair: Scott Johnson, ABC Labs. Ventura 120 1:40 DEVELOPMENT OF A MACROINVERTEBRATE IBI FOR SOUTHERN COASTAL CALIFORNIA AND USE OF PROBABILISTIC SAMPLING FOR REGIONAL STREAM CONDITION ASSESSMENTS. P. R. Ode, A. C. Rehn* and J. T. May. Cal- ifornia Department of Fish and Game, Rancho Cordova, CA. 121 2:20 ALGAE-NUTRIENT RELATIONSHIPS AND TMDL DEVELOPMENT IN MALIBU CREEK, CALIFORNIA. S. L. Luce*!, R.E Ambrose? and M.A. Abramson'. 'Heal the Bay, Santa Monica, California; 7University of California, Los Angeles, California. 3:00 BREAK 122 3:20 FRESHWATER STREAM INVERTEBRATES: RESPONSE TO PHYSICAL HABITAT ALTERATION AND WATER QUALITY IMPAIRMENT IN SOUTHERN CALIFORNIA. B.H. Isham*. B.T. Ferguson Weston Solutions, Inc., Carlsbad, CA. 123 4:00 THE APPLICATION OF STREAM BIOASSESSMENTS IN POINT AND NON- POINT SOURCE REGULATORY PROGRAMS. S. Johnson. 124 4:20 USE OF IN SITU HATCHBOX STUDIES TO EVALUATE WATER QUALITY EFFECTS. H. Bailey', B. Chalmers’, and J. Elphick'. 'Nautilus Environmental, San Di- ego, California; 7Myra Falls Mine, Campbell River, British Columbia. Saturday, May 21, 2005 Location: Hilton Business Center, Rm. 300a Session: Research Training Program: Session I Chair: Martha Schwartz 125 9:40 THE EFFECTS OF SEQUENCING: MEMORY ITEMS VS. PERCEPTUAL LEARNING. L. Calfas' and P. Kellman’. Marlborough School', Los Angeles, CA, 90004; UCLA?’, Department of Psychology, Los Angeles, CA, 90095. 126 10:00 CREB-MUTANT PERFORMANCE IN A NOVEL LEARNING TASK. D: Chin. Alhambra High School, Alhambra, CA. Mentor: Dr. Amelia Russo-Neustadt. 127 10:20 OPERATIONAL EFFECTS OF ALTERED ABIOTIC FACTORS ON NITRI- FYING BACTERIA: YEAR 2. Sanjit Datta. Palos Verdes Peninsula High School and Cabrillo Marine Aquarium, San Pedro, CA 90731. 10:40 BREAK 11:00 Plenary Talk: Dr. James Powell: The Grand Canyon: Solving Earth’s Grandest Puzzle. 12:00—1:20 LUNCH BREAK PROGRAM 13 128 129 130 131 132 133 134 135 136 137 Session: Research Training Program: Session I (Continued) Chair: Richard Schwartz 1:20 STRAIN RELATEDNESS OF CANDIDA IN HUMANS: A URINARY PATH- OGEN OR COLONIZER? (PHASE 2). Joon-Bok Lee. California Academy of Math and Science, and Division of Infectious Diseases, Los Angeles County Harbor-UCLA Medical Center, 1000 W. Carson Street, Torrance, California 90502. 1:40 MAINTAINING CORRECT BALANCE: SPATIAL CODING AND ITS DEPEN- DENCE ON NATURAL STIMULI. D.E. Lluncor. Research Training Program, Palos Verdes Peninsula High School, Rolling Hills Estates, CA, 90274. 2:00 EFFECTS OF ATMOSPHERIC CARBON DIOXIDE ON THE NITROGEN FIX- ATION CAPABILITIES OF TRICHODESMIUM. S.F. Ong, J. Sohm, and D.G. Ca- pone. California Academy of Mathematics and Science, Carson, CA 90747; Wrigley Institute for Environmental Science, University of Southern California, Los Angeles, CA 90098. 2:20 USING THE INHIBITORY EFFECTS OF ATP ANALOGS TO REGULATE MRNA PROCESSING: YEAR IL. Carol Y. Suh. Palos Verdes Peninsula High School, and University of California, Los Angeles, Department of Chemistry and Biochemistry, Los Angeles, CA, 90095: 2:40 STUDY OF THE EFFECTS OF NEURAL LAZARILLO OVEREXPRESSION IN TRANSGENIC DROSOPHILA MELANOGASTER. Derek Tam. Alhambra High School. Mentor: Julien Muffat (laboratory of Pr. Seymour Benzer). 3:00 BREAK 3220 3D MODEL OF ALGORITHM PERFORMANCE ON THE 3-SATISFIABILITY PROBLEM. Timothy Uy, California Academy of Math and Science; and Dennis Kibler, Department of Computer Science, University of California: Irvine, Irvine, California 92697- 3425. 3:40 PROSTATE CANCER PREVENTION BY POLYPHENOLIC COMPOUNDS IN GREEN TEA. Elysia Chin. Alhambra High School and University of Southern Cal- ifornia, Keck School of Medicine, Los Angeles, CA, 90033. 4:00 Presentation by students who went to National AAJAS Meeting and student Intel Science Contestants. Saturday, May 21, 2005 Location: Hilton Business Center, Rm. 3006 Session: Research Training Program: Session II Chair: Kathy Phalen 9:40 IMPORTANCE OF DROSOPHILA EIF4E-BINDING PROTEINS IN LIFESPAN REGULATION. Tony Au Lu. Alhambra High School. Mentor: Brian M. Zid; Teacher: Mr. Duane Nichols. 10:00 MOTHER’S CHARACTRISTICS AND HER CHILD FEEDING HAB- ITS. April Stephenson and Maivy Nguyen. Dr. Fary Cachelin, California State Univer- sity Los Angeles, Department of Psychology, Los Angeles, CA, 90041. 10:20 ROLES OF AUXOTROPHIC MARKERS IN CANDIDA ALBICANS VIRU- LENCE. D. Im, California Academy of Math and Science; and H. Park, Division of Infectious Diseases, Department of Medicine, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA 90502. 10:40 BREAK 11:00 Plenary Talk: Dr. James Powell: The Grand Canyon: Solving Earth’s Grandest Puzzle. 12:00—1:20 LUNCH BREAK 138 139 140 141 142 143 144 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES Session: Research Training Program: Session II (Continued) Chair: Harry Takahashi 1:20 PREDICTING MATERIAL FAILURE: CORRELATION BETWEEN DEFOR- MATION LUMINESCENCE AND HYSTERESIS. Geoffrey H. Woo. UCLA, Depart- ment of Physics and Astronomy, Los Angeles, CA 90095-547. 1:40 CHANGES IN DENSITIES OF FECAL INDICATOR BACTERIA (FIB) OVER DIFFERING TIDAL FLOWS IN THE BALLONA WETLANDS, LOS ANGELES. S. Yanamadala! and John H. Dorsey’. 'Chadwick High School, 26800 S. Academy Drive, Palos Verdes Peninsula, CA, 90274; *7Loyola Marymount University, Department of Natural Sciences, Los Angeles, CA, 90045. 2:00 POLYPHENOL EFFECT ON SUSCEPTIBILITY OF OXIDIZED B-AMYLOID PEPTIDE TO INSULIN DEGRADING ENZYME. J. Young. Alhambra High School and USC Keck School of Medicine, School of Pharmacy, Department of Pharmaceutical Science, Los Angeles, CA, 90089. 2:20 EFFECTS OF SALINITY CONCENTRATION ON RATES OF POLYP CLON- ING, GROWTH, AND STROBILATION IN THE AURELIA LABIATA (CNIDARIA, SCYPHOZOA). Julie A. Guerin. Cabrillo Marine Aquarium, San Pedro, CA 90731 (Pal- os Verdes Peninsula High School, Rolling Hills Estates, CA 90274). 2:40 MECHANISM OF FAILED ALVEOLARIZATION FOLLOWING IN UTERO NICOTINE EXPOSURE. Kabre, Sanyl. Hawthorne High School, Hawthorne, CA. 3:00 BREAK 3220 SEASONAL CHANGES AND YEAR-TO-YEAR VARIABILITY OF THE NORTHERN WATER ICE CAP FROM MARS GLOBAL SURVEYOR; MARS ORBITER CAMERA AND THERMAL EMISSION SPECTROMETER. Katherine Lu and Angela Guo. Alhambra High School. 3:40 CONDITIONAL KNOCKOUT OF LMO4. Jerry Kwong, Yu Zhenquan, and Bogi Andersen. University High School and University of California Irvine, School of Medicine. 4:00 Presentation by students who went to National AAJAS Meeting and student Intel Science Contestants. ABSTRACTS 1 SOUTHERN CALIFORNIA WETLAND RECOVERY PROJECT Mary Small. State Coastal Conservancy The Southern California Wetland Recovery Project (WRP) began in 1998 with the execution of an agreement that committed 17 state and federal agencies to develop and implement a regional plan for acquisition and restoration to increase the quantity and quality of the region’s wetlands. The geographic scope of the WRP includes coastal wetlands and watersheds from Point Conception south to the U.S. Mexico border. The long-term objective of the WRP is to reestablish a mosaic of fully functioning wetlands systems, with a diversity of habitat types and connections to upland communities, which preserves and recovers self-sustaining populations of species. In the Regional Strategy, the WRP identified the following regional goals: Preserve and restore coastal wetland ecosystems. Preserve and restore stream corridors and wetland ecosystems in coastal watersheds. Recover native habitat and species diversity. Integrate wetlands recovery with other public objectives. Promote education and compatible access related to coastal wetlands and watersheds. Advance the science of wetlands restoration and management in Southern California. OE a To achieve these goals, the WRP has developed a broad-based partnership that includes 17 state and federal agencies working in concert with scientists, local governments, environmental organizations and business leaders. The WRP helps implement priority acquisition and restoration projects. In ad- dition, the WRP awards small grants for projects that involve the public in hands-on restoration activities. The Science Advisory Panel of the WRP is developing a long-term, region-wide monitoring program for southern California wetlands and riparian areas. pe BALLONA WETLANDS-—COMMUNITY BASED RESTORATION PLANNING Mary Small. State Coastal Conservancy After more than thirty years of contentious land use dispute, last spring the State of California became the owner of more than 600 acres of the former Ballona Wetlands in Los Angeles. The site is near the mouth of Ballona Creek and is considered to be one of the best remaining opportunities for landscape-scale wetland restoration in Los Angeles County. However, there are significant con- straints that may limit restoration activities, including existing infrastructure and easements. The res- toration plan will seek to restore and enhance salt water influenced wetland habitat while also providing for wildlife-oriented public access and recreation opportunities where compatible. In September 2004, the State Coastal Conservancy, the California Department of Fish and Game and the State Lands Commission began a community based restoration planning process to develop a plan for interim site mahagement and long-term enhancement of the property. The agencies have structured a planning process incorporates scientific input and is also transparent to all of the community’s stakeholders. Restoration planning is expected to take up to three years. 3 ORMOND BEACH: RESTORATION OF HISTORIC WETLANDS Peter Brand. State Coastal Conservancy Ormond Beach is considered by wetland experts to be the most important wetland restoration opportunity in southern California. Prior to development, the coast of Ventura was a vast complex of dunes, lakes, lagoons, and salt and freshwater marshes. From the Santa Clara River estuary to the beginning of Mugu Lagoon, it appears from historic maps that there were seven lagoons. Most have either disappeared, been severely degraded, or been converted to marinas or ports. Nevertheless, this is the only place in southern California where it is still possible to restore close to the historic extent of wetlands. The wetlands at Ormond Beach once covered approximately 1,000 acres; approximately 250 acres remain. The Coastal Conservancy has acquired 265 acres and expects to close soon on the acquisition of another 276 acres. The Conservancy has begun a restoration feasibility study for Ormond Beach 15 16 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES and adjoining wetlands that would show how this area could be restored and linked hydrologically and as an ecosystem. A critical mass of 750 acres of restored wetlands and associated habitat at Ormond Beach is expected to create a self-sustaining biological system and enough tidal prism and flushing action to maintain health and hydrologic function. Anticipated restoration at Ormond Beach would include modifications of the site hydrology to restore tidal action and bring back freshwater flows that had formerly drained across the Oxnard Plain to the coastal wetlands. When integrated with the adjoining 900 acres of freshwater wetlands and the 1,500 acres at Mugu Lagoon, this could be the largest coastal wetland in southern California, spanning nine miles of the coast from Point Hue- neme to Point Mugu. 4 THE MALIBU LAGOON ENHANCEMENT PROJECT C.S. Shuman. Heal the Bay, 3220 Nebraska Ave., Santa Monica, CA 90404 Malibu Lagoon is a 31 acre shallow water estuarine system that has been degraded by habitat encroachment and poor water quality. Previous restoration efforts led by California State Parks in the 1980’s successfully restored some wetland habitat but did not adequately restore the natural structure and function to the estuarine ecosystem. The current configuration does not allow for adequate water circulation that, in addition to existing water quality impairments for nutrients and bacteria, promotes degraded water quality and habitat conditions. To address this situation, the California State Coastal Conservancy, in cooperation with California State Parks, has initiated the preparation of a restoration and enhancement plan for Malibu Lagoon. This project identified and evaluated design options to restore the natural structure and function to the lagoon ecosystem, while minimizing impacts to existing brackish marsh habitat. All restoration options were designed to maintain existing access and increase opportunities for interpretation, edu- cation and stewardship for the 1.5 million annual visitors to the site. A collaborative approach directed by input from the Lagoon Technical Advisory Committee and the Lagoon Restoration Working Group was used to identify the restoration alternative that is expected to most readily achieve the biological and social goals of the project while introducing the least amount of impact to the existing lagoon ecosystem. A phased restoration implementation and long-term adaptive management approach will be implemented to maximize the ecosystem benefits of this restoration process. 5 ECOSYSTEM RESTORATION AT TIJUANA ESTUARY, CALIFORNIA Chris Nordby. Tierra Environmental Services, 9915 Businesspark Avenue, Suite C, San Diego, CA'92131 Tijuana Estuary is a complex ecosystem that has been highly modified by human land use practices. The estuary is located entirely within San Diego County, California, although three fourths of its watershed is in Mexico. Unregulated land development within the Mexican portions of the watershed has resulted in an increased sediment supply throughout the watershed. As a result, sensitive wetland habitats have been buried, converting once productive salt marsh to ruderal upland habitats. Management of the estuary 1s entrusted to a multi-agency Management Authority, which recognized the consequences of uncontrolled sediment deposition on the system. The Management Authority recommended two broad goals to reverse the trend of wetland loss: 1) Control sedimentation within the watershed, and 2) Restore areas degraded by sedimentation. In the 1980's, the California State Coastal Conservancy initiated plans for controlling sediment and restoring the estuary. Working with Southwest Wetlands Interpretive Association, a non-profit orga- nization, and Tierra Environmental Services the Conservancy has accomplished the following mile- stones: ® Constructed a 2.5-acre channel connecting formerly landlocked portions of the estuary to reduce sedimentation in backwater areas; ® Constructed a 20-acre Model Marsh project to restore intertidal salt marsh in an area subjected to disturbance; @ Constructed a series of managed sediment basins to control areas of high sediment deposition; ® Funded a study to restore approximate 250 acres of degraded habitat in the southern portion of the estuary. These efforts have contributed to the reversal of human disturbance of the wetland: however, sediment continues to present management challenges. ABSTRACTS ej 6 RESTORING WETLANDS ON A GRASSROOTS LEVEL—NON-PROFITS AND WET- LAND RESTORATION D. Gibson. San Elijo Lagoon Conservancy Executive Director/Principal Scientist, Encinitas, CA 92023 The San Elijo Lagoon Conservancy (SELC) is a non-profit organization that began in 1987 out of concerns of development surrounding the San Elijo Lagoon Reserve. The organization built a mem- bership of over 2,000 members and began educating its members. In 1995, the SELC hired an exec- utive director with a scientific background and began conducting research and restoration projects. Currently, SELC maintains over 20 years of baseline data for water quality, fish, invertebrates, and bird data. SELC has raised over $10 million for projects and now employs 5 full time employees. SELC has written the San Elijo Lagoon Action Plan, which led to the baseline biological report for the full restoration of the lagoon for the Army Corps Of Engineers. This project encompasses moving infrastructure and removing past impacts to the system that have muted the tidal prism and changed habitat. SELC has also conducted studies that analyzed the sediment throughout the lagoon and are in the process of creating an Action Plan for the Escondido Creek Watershed, which drains into the San Elijo Lagoon. This past year we began one of the largest invasive species removal projects that have been funded by the State. The $4 million project will remove over 300 acres of invasive species from the riparian corridors of the Carlsbad Hydrologic Unit, of which the Escondido Creek watershed is a part. The SELC has been very successful in both restoring and enhancing habitat, as well as serving as a critical partner for federal, state and local government. 7 THE JOURNEY FROM WETLANDS TO OIL FIELD AND BACK Jim Trout. State Lands Commission The presentation will discuss the conversion of historic natural wetlands to commercial and oil field development and back to wetlands, all in a century. Bolsa Chica lowlands in Huntington Beach, Orange County, were, in part, tide and submerged lands at the time of California statehood in 1850. A natural opening to the ocean existed near the current location of Warner Ave. and Pacific Coast Highway. This opening closed up after the lowlands were converted to farming operations and later into a duck-hunting club. In the 1950’s oil was discovered the area and development of that resource was begun. The duck club was phased out while dikes, roads and oil drilling production pads were constructed in the lowlands. Oil continues to be produced from the lands today. In the 1960’s and °70’s, attempts were made to develop the lowlands for residential housing. The upper area was built up into residential subdivisions. The lowland ownership was split into surface and mineral estates and efforts made to develop the surface for housing. Development in the lowlands was resisted by a number of environmental groups throughout 1970’s and 1980’s. A number of plans were considered but none were permitted. In 1995, the ports of Long Beach and Los Angeles needed to mitigate for harbor fill required to expand their deep-water multi-modal marine terminals. Agreement was reached with state and federal agencies whereby the ports would pay for mitigation credits, the funds to be used to acquire and restore the Bolsa Chica lowlands. In 1997 the ports and eight state and federal agencies implementing the restoration effort signed an agreement. The Agreement would fund acquisition 880 acres of the Bolsa Chica Lowlands (other than the subsurface mineral interests), purchase of the remaining production on 550 of those acres, abandon- ment of some oil and gas production facilities, and restoration of two-thirds of the area as wetlands, construction of a new inlet to the ocean with a new bridge over the inlet at Pacific Coast Highway. A full tidal regime would be established for 367 acres. Some 178 acres would have a muted tidal range, plus there will be nesting islands created for threatened and endangered birds as well as other amenities. A number of public town meetings were conducted and an environmental impact document pre- pared, a restoration plan adopted and final plans and specifications completed. Proposals were solicited from contractors during June and July of 2004, contractor selection made during August. Work began in the field November 1, 2004. A formal groundbreaking was held on October 6 at the site. Completion is scheduled for the end of July 2006. 18 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES 8 ENGINEERING OF THE BOLSA CHICA WETLANDS RESTORATION PROJECT Chris Webb, Michael McCarthy, Moffatt & Nichol; Jack Fancher, U.S. Fish and Wildlife Ser- vice; and Keith Merkel, Merkel & Associates The Bolsa Chica project is the largest salt marsh restoration project on the west coast, and represents the largest salt marsh restoration project by the USFWS. Eight government agencies forming the Steering Committee lead the effort, and a consulting team of five local firms performed the engineering for construction. Construction started last year and is rapidly progressing. The project has been active for nearly 30 years. It consists of restoring the former Bolsa Chica wetland at the historic mouth of the Santa Ana River (prior to it shifting south to its existing position). The site is approximately 1,000 acres in size and lies immediately inland from Pacific Coast Highway just north of Huntington Beach. It represents a critical link along the Pacific Flyway for use by endangered birds such as the Western snowy plover and California least tern. The project includes installation of a new ocean entrance stabilized by jetties that will connect to a deepwater basin will be dredged on approximately 365 acres contained by dikes, and will feed peripheral muted tidal areas over 200 acres through culverts in the dikes. New subtidal areas are being created for fish, mudflats and vegetated intertidal areas are being created for invertebrates and birds, and three new large nesting islands are being created for snowy plovers and least terns. Construction affects existing habitats, so other existing sensitive areas are being preserved and enhanced to offset effects for net benefits. Dredging will create a large mound of sandy fill in the shallow ocean off of the inlet, and beach nourishment along Bolsa Chica State Beach. New bridges are being constructed at the future inlet on Pacific Coast Highway and within the oil field. A significant groundwater control device is being installed along the project boundary nearest adjacent homes. Construction will last until 2007. Challenges during construction include the extremely wet winter of 2004—05, sensitive species nesting in spring seasons of 2005 and 2006, and existing constraints related to oil field operation, use of the state beach, site clean-up activities, and other factors. These issues are addressed and related in the presentation. 9 USING SPATIALLY-EXPLICIT MODELS TO PREDICT EELGRASS DISTRIBUTION FOR RESOURCE MANAGEMENT AND RESTORATION Robert Mooney. Merkel and Associates Inc. A model that predicts potentially suitable eelgrass habitats was developed using eelgrass habitat requirements. The predictive model is a spatial, numerically-based, static habitat suitability index (HSI) model focusing on physical parameters that contribute to the observed distribution patterns of eelgrass. Data on eelgrass distribution, bathymetry, maximum orbital velocity, residence time, salinity, and hours of light saturation were combined to create the predictive model. Each spatially explicit theme was used to depict the range of environmental parameters affecting eelgrass distribution. The modeling framework used for the predictive eelgrass model was the Ecological Limits, Viability, and Sustain- ability (ELVS) model, which was originally developed by Merkel & Associates in order to make eelgrass habitat suitability predictions from bathymetric, hydrodynamic, and atmospheric data. This predictive model of suitable eelgrass habitat will provide resource managers improved capabilities to detect and track changes in eelgrass resources. 10 EVALUATING THE SUCCESS OF WETLAND MITIGATION IN LOS ANGELES AND VENTURA COUNTIES: ASSESSING PERMIT COMPLIANCE AND WETLAND CONDI- TION R.F. Ambrose and S.E Lee. Environmental Science and Engineering Program and Department of Environmental Health Sciences, University of California, Los Angeles, CA 90095-1772 The Clean Water Act provides the most important protection of wetlands in the United States; an important element of this protection is the requirement for compensatory mitigation, by which wetland resources are created or restored to compensate for losses due to impacts to natural wetlands. In this study, we assessed 50 compensatory mitigation projects required by the Los Angeles Regional Water Quality Control Board in Los Angeles and Ventura Counties through an extensive review of permit files and field monitoring to map the area of the mitigation sites and assess (1) compliance with permit ABSTRACTS 19 conditions and (2) habitat condition. Twenty mitigation projects had multiple locations, yielding 79 individual mitigation site evaluations. A majority of the sites (69%) complied with all of their (as- sessable) permit conditions. Overall, the mitigation projects met their acreage requirements; omitting projects with undetermined boundaries, the total acreage lost in our assessment permits was 56 ha, the acreage required was 80 ha, and the acreage we measured was 91 ha. However, many of the mitigation sites did not have optimal wetland condition. Using a modified version of the California Rapid Assessment Methodology (CRAM), which assesses 15 different metrics in four main categories, we determined that 29% of the sites were in marginal to poor condition, 67% were of sub-optimal condition, and only three sites (4%) were in optimal condition. We conclude that the goal of no net loss of wetland functions and services has not been achieved in the Los Angeles region. 11 DEVELOPMENT OF AN INTEGRATED REGIONAL ASSESSMENT PROGRAM FOR SOUTHERN CALIFORNIA WETLANDS E.D. Stein, M. Sutula, and A.E. Fetscher. Southern California Coastal Water Research Project, 7171 Fenwick Lane, Westminster, CA 92683 Historic and continued loss of wetland and riparian systems is one of southern California’s most pressing natural resource management issues. In 1997, the southern California Wetlands Recovery Project (WRP) was formed to increase regional coordination of wetland preservation, restoration, and management among 17 state and federal agencies. As of September 2003, the WRP had spent of $61.8 million on 34 wetland acquisition, restoration and enhancement projects. However, the WRP currently lacks the ability to assess the progress of regional wetland ecosystem recovery, relative to continued wetland loss and degradation. To address this shortcoming, the WRP is developing an integrated wetlands regional assessment program (IWRAP) that will assess status and trends of wetland condition, measure recovery progress, evaluate the effect of anthropogenic stressors, and evaluate the effect of wetland management actions on the regional wetland ecosystem. The TWRAP will encompass all tidal and non-tidal wetland classes within southern California’s coastal watersheds, and is based on a three-tiered assessment design: Level J assessment evaluates extent and distribution of wetlands and associated resources. Level I] assessment evaluates wetland condition and stressors on a regional scale. Level I/II assessment addresses detailed management questions of stressors and condition on a site-specific scale. Key elements of the TIWRAP are that 1) assessment questions are directly linked to management questions; 2) the intensity of a specific assessment is commensurate to the importance of the management question being addressed; 3) assessments are adaptive, and choices regarding special studies and other intensification efforts are informed by the results of coarser monitoring; 4) assessments are cost-effective, yet scientifically rigorous; and 5) project specific performance moni- toring is consistent with ambient assessment. The estuarine component of the IWRAP includes 13 assessment questions that will evaluate wetland condition relative to areal extent, hydrology, sediments, contaminants, biota, and landscape context. When fully implemented, the TIWRAP will streamline reporting of monitoring data, making them more accessible for routine scientific evaluation of resto- ration and management techniques, and will help to evaluate recovery priorities and ensure that WRP use of public funds has a lasting regional impact. 12 MONITORING PLAN FOR THE SAN DIEGUITO LAGOON RESTORATION PROJECT Page, H. M., S. C. Schroeter, D. C. Reed, R. EF Ambrose, and M. A. Steele. Marine Science Institute, University of California, Santa Barbara, CA, 93106, Environmental Science and En- gineering Program, University of California, Los Angeles, CA, 90095 The San Dieguito Wetlands Restoration Project is required of Southern California Edison by the California Coastal Commission as mitigation for the operation of the San Onofre Nuclear Generating Station (SONGS). The restoration will consist of the creation of 115 acres of tidal wetlands with an additional 35 acres credit given for a commitment to maintain the lagoon inlet in an open condition in perpetuity. Habitats to be created in the restoration include subtidal, intertidal mudflat, coastal salt marsh, and transitional wetland. The success of the restoration will be evaluated using performance standards outlined in the Coastal Development Permit for the operation of SONGS. The restoration project is required to meet both physical (e.g., topography, water quality) and biological (e.g., fish, invertebrates, birds, vegetation) performance standards. A monitoring plan has been developed to guide the post-restoration monitoring work that will measure the success of the restoration project in achiev- 20 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES ing the performance standards. This plan includes the physical and biological performance standards on which the success of the restoration will be evaluated and recommended sampling methods for collecting the information needed to evaluate each standard. Key elements of monitoring program include independent monitoring and the use of reference sites in evaluating wetland performance. 13 QUANTIFYING THE PERFORMANCE OF DIFFERENT REEF DESIGNS ON KELP BED FISH AND BENTHIC COMMUNITY DEVELOPMENT AT THE SAN CLEMENTE EXPER- IMENTAL ARTIFICIAL REEF Dan Reed', Stephen Schroeter', David Huang!, Todd Anderson’, and Robert Grove?. 'Marine Science Institute, University of California, Santa Barbara, CA 93106. reed @lifesci.ucsb.edu; *Department of Biology, San Diego State University, San Diego CA 92182; *Southern California Edison Company, Rosemead, CA 91770. grovers@sce.com Determining the success of an artificial reef as a tool for mitigating human-induced losses to fish populations and benthic communities requires explicit standards for assessing the performance of the reef and a robust monitoring program that is designed to collect the information necessary to evaluate those standards. The effects of material type (recycled concrete vs. quarry rock) and bottom coverage (30 to 90%) on fish and benthic community development were evaluated over a five year period in a large scale (~ 9 ha) artificial reef experiment off of San Clemente. Here we describe: 1) the biological performance standards established for kelp bed fishes and benthic communities on an artificial reef that will be built to compensate for the loss of kelp bed habitat caused by the operation of a coastal power plant in, San Onofre Nuclear Generating Station, Units 2&3 (SONGS); 2) an assessment of different methods of evaluating those standards; and 3) results of the five-year experiment that tested the efficacy of six different artificial reef designs in meeting these performance standards. Initial colonization by macroalgae was high on all reef designs. Overall, the abundance and species richness of macroalgae steadily declined over time while the abundance and species richness of sessile inver- tebrates steadily increased. The abundance of sessile invertebrates was positively correlated with the bottom coverage of reef material. The fish observations suggest that all six reef designs tested provide suitable habitat for kelp forest fishes and most likely would meet the SONGS performance standards for fish. 14 EVALUATION OF KELP (MACROCYSTIS PYRIFERA (L.) C. AGARDH) KELP RES- TORATION OFF TAJIGUAS, CALIFORNIA USING SCATTEREDGRANITIC BOULDERS IN A SAND HABITAT D. C. Barilotti, D. C. Lees and D. M. Schroeder. Sea Foam Enterprises, San Diego CA 92107, seafoam@mindspring.com; Littoral Ecological & Environmental Services, Leucadia, CA 92024, dennislees@earthlink.net; Marine Science Institute, UCSB, Santa Barbara 92106, schroed @ lifesci.ucsb.edu The Tajiguas Kelp Habitat (TKH) was constructed May 6, 1999, in a 0.72 ha area offshore of Tajiguas, California at water depths between 8.5 and 10.4 m (MLLW). It’s in relatively pristine waters (they receive minimal pollutants from urban development), sea otters are present occasionally, and casual observations over 20+ years indicate that Macrocystis juvenile recruitment events occur con- sistently. TKH performance satisfied California Coastal Commission mitigation requirements speci- fying construction of a new kelp habitat that would produce by November 2002, at least 470 adult plants living more than one year. In addition to meeting mitigation requirements, its performance is also meeting long-term criteria for creating a persistent kelp habitat by converting a sand habitat, where kelp persistence was low, into one that provides substrate for kelp recruitment and anchorage and that has minimal destructive sea urchin grazing problems. Design features to help meet long-term criteria, included: (1) Placing granitic rocks into sandy areas where the sand covering the bedrock was too shallow to allow complete rock burial. (2) Spacing rocks so, for the most part, they did not touch each other, thereby minimizing the number of habitats where sea urchins would be protected from predators. (3) Locating TKH adjacent to a natural kelp bed growing on bedrock that could provide TKH both a source of spores for recruitment, if artificial kelp propagation techniques failed, and sea urchin predators (invertebrate and fish) to help prevent destructive sea urchin grazing that occurs in other Tajiguas area kelp beds. ABSTRACTS om 15 “FLOATING” BEHAVIOR OF GRANITIC BOULDERS USED TO CONSTRUCT THE TA- JIGUAS KELP HABITAT ON A SAND PLAIN AND COMPARISON OF THE DEVELOP- ING EPIBIOTIC INVERTEBRATE ASSEMBLAGE WITH NEARBY NATURAL REEF AS- SEMBLAGES Dennis C. Lees and D. Craig Barilotti. Littoral Ecological & Environmental Services, Leucadia, CA 92024 and Sea Foam Enterprises, San Diego, CA 92107 Following removal of underwater pipelines through kelp beds in Santa Barbara County, we were asked to create an artificial kelp habitat offshore of Tajiguas. In response, the rocky 0.7 hectare Tajiguas Kelp Habitat (TKH) was constructed in a thin layer of sand over bedrock offshore from a natural kelp reef. Approximately 1,140 quarry rocks =0.6 m in diameter were scattered over the project area to provide ~16 percent of the seafloor. We monitored: ‘floating’? behavior of 30 randomly selected rocks; and sand depth throughout TKH for 18 months. Recently, we conducted a 5-year survey to assess long-term conditions of the rocks and the epibiota. In areas where sand overburden was less than 0.3 m deep prior to habitat construction, sand washed out and the introduced rocks were resting on exposed bedrock. In areas with deeper sand, the boulders were still basically “‘floating’’ on the sand. Thus, the rocks appear to provide long-term substrate suitable for kelp recruitment and survival. The rich epibiotic assemblage that has developed on the rocks comprises a variety of primarily ephemeral suspension-feeding invertebrates dominated by bryozoans, hydroids, tunicates, and sponges. A comparison with the mature epibiota on nearby natural reefs suggests that the TKH epibiota is at an early stage of succession. Differences in species composition are probably driven by differences in disturbance, relief, and habitat “‘age’’. Dense beds of large tubicolous polychaetes (Diopatra ornata) have developed in interstices among the rocks within TKH. These probably contribute more to fish biomass than any other species. 16 COMPARISON OF REEF FISH ASSEMBLAGES AMONG NATURAL ROCK HABITATS AND THE CREATED TAJIGUAS KELP HABITAT IN THE SANTA BARBARA CHANNEL D. M. Schroeder and D. C. Barilotti. Marine Science Institute, University of California, Santa Barbara, CA 93106, schroed@lifesci.ucsb.edu; and Sea Foam Enterprises, 4369 Osprey Street San Diego CA 92107 Mitigation of natural resource damage may require directed restoration or creation of in-kind habitat. Typically, a mitigation project begins by manipulating abiotic factors Gf necessary) at the targeted site and then establishing the foundation or architectural species, such as giant kelp, that defined the damaged habitat, with the expectation that missing species will have the potential to colonize the new habitat by natural or artificial means. To understand how reef fish assemblages responded to a created giant kelp habitat, we describe patterns of species composition and abundance at a manipulated area, the Tajiguas Kelp Habitat (TKH), and six reference sites within the Santa Barbara Channel region. The six reference sites represent a range of potential fish assemblages found within the study region, and were used to formulate simple ‘‘standing stock’’ performance measures to determine if TKH successfully met expectations. Performance measures included minimum levels of species richness and diversity, and whole-assemblage requirements based on degree of similarity to nearby versus distant reference sites. TKH met or exceeded all of these “standing stock”? performance measures. Ideally, successful mitigation integrates the new habitat across larger temporal and spatial scales, emulating ecological trajectories (e.g. population dynamics, successional stages) of reference systems. These kinds of trajectories have not been measured at TKH, and require further investigation. WZ, POSITIVE INDIRECT EFFECTS OF REEF FISHES ON GIANT KELP PERFORMANCE Davenport, Andrew C. San Diego State University Previous studies have suggested that microcarnivorous reef fishes may regulate or reduce grazing invertebrates, yielding positive indirect effects on giant kelp performance, thus preventing infestations that could have severe impacts or potentially destroy kelp forests. In 2003, I examined the effects of invertebrate herbivores on giant kelp performance in the presence and absence of their predators on plots of giant kelp in three treatments: predator access, predator exclusion, and a cage control. There was a Significant increase in invertebrate herbivore density and an effect on kelp performance on plots N N SOUTHERN CALIFORNIA ACADEMY OF SCIENCES of giant kelp in which predators were excluded than on plots open to predators. Cage controls indicated that exclusion pens neither enhanced nor inhibited invertebrate herbivore densities or kelp perfor- mance. To determine if my results from the previous experiment apply to continuous reefs, I examined the effects of invertebrate herbivores on giant kelp performance in the presence and absence of their predators within a continuous kelp forest. In 2004, predator exclusion cages were deployed within a giant kelp forest and compared with designated open sections of the forest in a stratified random design with treatments at the edge, middle, and back of the kelp forest. There was a significant increase in invertebrate herbivore density and an effect on kelp performance within the continuous reef. In addition, invertebrate herbivores and microcarnivorous fishes were inversely related among nine kelp forests, suggesting that these effects may occur from small to large scales. 18 MARINE RESERVE DESIGN: DETERMINING AN OPTIMAL SIZE AND LOCATION P.E. Parnell', Paul K. Dayton', and Cleridy Lennert-Cody’. 'Scripps Institution of Oceanogra- phy, UCSD, La Jolla, CA 92093-0227; 2Inter-American Tropical Tuna Commission, 8604 La Jolla Shores Drive, La Jolla, CA 92037-1508 ‘*How big should a marine reserve be?” This is the most common question asked of MPA advocates whose replies are usually subjective based on an intuitive optimization of various objectives. A rule of thumb that 20-50% of targeted habitats should be protected within marine reserves has evolved over the last couple of decades based mainly on stock enhancement ideals for a few well-studied stocks. Here, we advocate a less subjective and more case specific approach based on the protection of critical habitat for entire sets of exploited species over an area large enough to protect individuals during their post-larval life stages. We have developed an algorithm to identify an optimal size and specific location for individual marine reserves based on the importance of habitat to all exploited species, the distribution of these habitats, and the post-recruitment mobility of these exploited species. We applied the algorithm to design an optimal marine reserve to protect twenty exploited species within the hard-bottom habitats of La Jolla, CA. 19 BEHAVIORAL THERMOREGUALTION OF THE LEOPARD SHARK (T7TRIAKIS SEMI- FACIATA) IN THE NEARSHORE EMBAYMENTS OF SANTA CATALINA ISLAND, CAL- IFORNIA B.V. Ziegler. California State University Long Beach, Department of Biological Sciences, Long Beach, CA, 90840-3702 The leopard shark, 7Triakis semifasciata, is one of the most abundant nearshore elasmobranchs ranging from Baja California, Mexico to Oregon, with particular abundance in the bays of California. Mature female leopard sharks have been observed aggregating in Big Fisherman’s Cove (BFC) Santa Catalina Island for over 100 years; however, it is unclear why females aggregate in these shallow areas. During July and August of 2003, the numbers of aggregating sharks were counted in different sections of the shallow embayment at BFC (n = 36, mean + S.D. = 21.52 + 8.17) and water temperature was simultaneously monitored. Temperatures in the embayment ranged from 17.8—25.8C° (mean + S.D. = 21.8 + 1.2). Sharks preferred the warmest areas of the embayment (correlation r = 0.557, p<0.01) and moved to warmer locations over the course of the day. In addition, acoustic tracking, acoustic monitoring and archival transponder technology (Vemco Ltd., V13, V13-R256, VX32TP-Chat tags respectively) are being used to monitor mature female sharks’ body temperature, swimming depth, and movements at Catalina Island (n = 16). Acoustically monitored sharks show increased affinity to warmer shallow embayments around the island during the day than at night (p = 0.01). Preliminary results from archiving Chat tags suggest that shark body temperature is significantly warmer when in shallow water (r = 0.43, p<0.01), and that shark body temperature is warmer during the day than at night (p = 0.01). This form of behavioral thermoregulation may augment metabolic and physiological functions important for gestating females. ABSTRACTS DLS 20 MOVEMENT PATTERNS AND HABITAT USE OF OCEAN WHITEFISH (BRANCHIO- STEGIDAE) IN A SANTA CATALINA ISLAND MARINE RESERVE Bellquist, L.F.!, C.G. Lowe’, and J.E. Caselle*. '’California State University Long Beach, De- partment of Biological Sciences, Long Beach, CA 90840; *Marine Science Institute, University of California Santa Barbara, Santa Barbara, CA 93106 Knowledge of fish movement patterns over varying temporal and spatial scales is essential for effective management of fish populations. This study integrates acoustic telemetry and a GIS to quan- tify movement patterns, home range, site fidelity, and habitat use of ocean whitefish (Caulolatilus princeps) at the Catalina Marine Life Refuge (CMLR) located at Santa Catalina Island, California. Ten individuals were tagged with acoustic pingers (2 month battery life) and actively tracked to measure fine-scale movements and home ranges over multiple 24hr periods. Home ranges based on 95% kernel utilization distributions range from 90—348,966 m’, averaging 50,876 + 110,094 m? (+ SD). Individuals tracked were active during the day, using soft sediment habitats, but were inactive at night, taking refuge near rocky reefs. An additional seventeen fish were tagged with coded acoustic transmitters (lyr battery life), yielding continuous presence/absence information within and adjacent to the CMLR. To date (~8 months), 88% of the individuals acoustically monitored have shown longer- term fidelity to home ranges within the study site as well as consistent diurnal activity. Ocean whitefish home ranges extend beyond the reserve boundary, making this reserve less effective for protecting adult fish. 21 THE FISH ASSEMBLAGE OF AN ARTIFICIAL AND NATURAL REEF IN THE HORSE- SHOE KELP J.T. Froeschke', B.M. Haggin’, D.J. Pondella! and L.J. Allen. 'Vantuna Research Group, Occi- dental College, Department of Biology, Los Angeles, CA, 90041; *Nearshore Marine Fish Research Program, California State University, Northridge, Department of Biology, Northridge Cay DilssO Horseshoe Kelp is an extensive fish habitat near the Port of Los Angeles composed of several substrates types, including low relief and high relief rocky reefs, Laminaria beds, and coarse sand bottoms. As a result of the Deep Draft Improvement Project conducted by the U.S. Army Corps of Engineers and the Harbor Department of the Port of Los Angeles, hard bottom habitat was lost along the northern edge of Horseshoe Kelp (USACE 1997). Due to its proximity to the port, commercial and sport fishers currently and historically have utilized this area extensively. In 2001, a mudstone fishing reef was added to mitigate lost hard bottom habitat in the Horseshoe kelp. The newly created Fishing Reef, a nearby rocky reef, and Laminaria reef control habitats were monitored continually between September 2001 and October 2004 using underwater visual census methods. Fish transects were completed on the Fishing reef, a natural reef and the Laminaria beds during each sampling period. This interim assessment found that the turbidity, which was noted after reef construction, caused difficulties for sampling, persisted through Fall 2003 and abated in Spring 2004. Fish density was significantly lower on the Fishing Reef than the rocky reef control, but not the Laminaria reet control. This is an indication that the Fishing Reef is continuing to mature. Nonetheless, important fishery species including kelp bass (Paralabrax clathratus), California sheephead (Semicossyphus pulcher), barred sand bass (Paralabrax nebulifer), lingcod (Ophiodon elongatus), California scorpion- fish (Scorpaena guttata) and calico, gopher and vermilion rockfishes (Sebastes spp.) were found on the newly created Fishing Reef. 22 EFFECTS ON NEARSHORE ROCKY REEFS FOLLOWING THE REGIONAL BEACH SAND PROJECT L. Honma', B. Snyder’, and R. Rundle*. 'Merkel & Associates, 5434 Ruffin Rd, San Diego, CA 92123; 7AMEC Earth & Environmental, 5510 Morehouse Dr., San Diego, CA 92121; 3San Diego Association of Governments (SANDAG), 401 B Street Suite 800, San Diego, CA 92101 Over the past two decades, San Diego’s shoreline has experienced chronic and continuing erosion. In an effort to restore many of the beaches, in 2001, SANDAG implemented the Regional Beach Sand Project which dredged just over two million cubic yards of sand from four offshore borrow sites and replenished 12 beaches along the coast of San Diego County. Concern from resource agencies and 24 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES commercial fishermen regarding the potential for the sand placed on the beaches to impact nearby reefs promulgated monitoring of rocky intertidal, shallow subtidal, and kelp forest habitats in the vicinity of select receiver sites. Since implementation, there has been varied response and this presen- tation will discuss four years of shallow subtidal and beach profile monitoring data regarding coastal processes and its effect on nearshore reefs. 23 EVALUATION OF EELGRASS MITIGATION AND FISHERY ENHANCEMENT STRUC- TURES IN SAN DIEGO BAY, CALIFORNIA D. J. Pondella, II', L. G. Allen’, M. T. Craig’ and B. Gintert*. 'Vantuna Research Group, De- partment of Biology, Occidental College, Los Angeles, CA 90041; *Department of Biology, California State University, Northridge, CA 91330-8303; *Scripps Institution of Oceanography, La Jolla, CA 92093-0208; *Rosenstiel School of Marine and Atmospheric Science, Marine Biology and Fisheries Division, Miami, FL 33149 In 1997 to offset habitat loss and increase fishery production an eelgrass mitigation habitat was completed in San Diego Bay, California. This mitigation effort consisted of the transplantation of eelgrass, Zostera marina, in the lower portion of the bay. In addition to the establishment of a new eelgrass bed, four artificial reefs made of either quarry rock or concrete were created to further enhance fishery stocks and area’s ecosystem. Two design criteria and a direct comparison between quarry rock and concrete reefs were examined in this pilot program. These rocky-reefs and eelgrass habitats were monitored for five years by scuba. The newly created eelgrass habitat quickly performed at the level of the existing eelgrass bed and the overall analysis found that the mitigation eelgrass habitat was not significantly different from the reference eelgrass habitat in terms of fishes. Neither reef material (quarry rock or concrete) nor original reef design influenced fish utilization. In addition, aspects of fishery enhancement were examined using three species of rock bass from the genus Paralabrax (Perciformes: Serranidae). All age classes of kelp bass, Paralabrax clathratus, were present throughout the study. The density and distribution spotted bay bass, P. maculatofasciatus, indicated they utilized these enhancement reefs for foraging. Finally each age class of barred sand bass, P. nebulifer, signif- icantly predicted the subsequent age class. This indicates that these modules were successfully in providing habitat for recruitment and subsequent development through adulthood. Using artificial reefs and eelgrass transplantation, enhancement and mitigation goals were achieved in San Diego Bay. 24 LESSONS LEARNED, A HALF-CENTURY OF GIANT KELP RESTORATION IN SOUTH- ERN CALIFORNIA Mike Curtis. MBC Applied Environmental Sciences In the late-1950s attention was drawn to the loss of several kelp beds up and down the coast of southern California. Investigators such as Dr. Wheeler J. North began early investigations into the cause of the loss of kelp beds. These early investigations focused on the sometimes subtle effects of mans encroachment on the environment. Searching for answers, Dr. North found the unhealthy kelp beds infested with urchins, but urchins were normal in other kelp beds and did not cause substantial problems. Dr. North and his colleague Dr. Mary Clark, research scientists at CalTech determined that the interaction of sea urchins and sewage was responsible. With the determination that urchins were a large part of the equation in the disappearance of certain kelp beds, methodologies were sought to eliminate excess urchin populations and restore the kelp beds. Unrecognized in the early 1950s and 1960s, the effects of El Ninos and La Ninas also showed the role they play in the viability of our coastal kelp beds. Two basic techniques were pioneered by Dr. North to restore kelp beds. These include the tran- splantion of juvenile, subadult, and adult kelp from existing beds using several techniques for attach- ment and the laboratory growth of sporophytes and their outplanting. Both methodologies have been used successfully but can have vastly different results depending on the ecological interactions in the area being restored. One of the criticisms of restoration efforts is that it is a non-issue and that natural cycles will take care of the problem, some years are good and some are bad for kelp. We will explore this issue in relation to the probability of its applicability. Another criticism is that most of the growth of the restoration site is from natural revegetation, and that transplant efforts only contributed a minuscule portion of the kelp now present at the site. We will also determine if this criticism is credible. ABSTRACTS i) WN We will look at several giant kelp restoration projects conducted in the past half-century to glean lessons to use to determine whether, where, and even if, giant kelp restoration projects should be attempted as a viable option today. 25 GIANT KELP RESTORATION AND MONITORING IN SANTA MONICA BAY T. Ford. Santa Monica Baykeeper, P.O. Box 10096, Marina del Rey, CA, 90295 Giant Kelp, Macrocystis pyrifera, is a large brown algae that forms canopies, on the oceans surface. These algal beds provide bio-genic structure that attracts a great diversity of organisms. Persistent anthropogenic pressures and changes in oceanographic regimes have reduced the aerial extent of kelp communities within Santa Monica Bay. Historic kelp beds are restored through sea urchin relocation, sporophyll bag deployment, transplanting drifting kelp and outplanting laboratory cultured kelp. Mon- itoring is performed annually on reference, control, and restoration sites. Quadrat and band transect methods are used to determine the density and diversity of a suite of benthic organisms within these sites. Roving fish counts, adapted from REEF are used to determine the density and diversity of fishes within the same sites. To date 4,500 square meters of rocky reef have been restored into a giant kelp bed off of Malibu. Early data indicates the formation of kelp canopy within 8 months of the initiation of kelp restoration. Increases in the density of fish by 10 to 100 fold have been described. Increases in the diversity of fish species has increased by 18%. This project incorporates volunteers who are trained to assist project biologists with the restoration and monitoring. 26 COMPARISON OF DIGESTIVE ENZYME ACTIVITIES IN TUNAS AND THEIR ECTO- THERMIC RELATIVES D. L. Neumann and K. Dickson. California State University, Fullerton, Department of Biology, Fullerton, CA 92831 Tunas are known to elevate the temperature of their aerobic locomotor muscle, and some tuna species can also maintain elevated visceral temperatures. Tunas are effective predators, swim contin- uously, and have high metabolic rates. Their diet consists primarily of large quantities of protein and lipids. In tunas, the largest visceral organ is the caecal mass, which is thought to increase the surface area for digestion and absorption. This study was a comparison of digestive enzyme activities in tunas and their close ectothermic relatives, to test the hypothesis that enzyme activities are greater in the endothermic tunas. Two tuna species [yellowfin tuna (Thunnus albacares), a species that warms its muscle but not its viscera, and albacore tuna (Thunnus alalunga), a species that warms both the muscle and viscera] were compared with the ectothermic chub mackerel (Scomber japonicus) and eastern Pacific bonito (Sarda chiliensis). The specific activities of pepsin in the stomach and lipase in the caecal mass and intestine were measured at 15°C and 25°C and trypsin in the intestine and caecal mass were measured at 20°C and 25°C, with spectrophotometric assays. It was predicted that the caecal mass of endothermic species would exhibit higher digestive enzyme activities than that of non- endothermic species. High enzymatic activities in the caecal mass would support its importance in digestion. If enzymatic activities were significantly higher in the endothermic albacore at its elevated visceral temperature, this would suggest elevated visceral temperatures is likely to speed up processes of absorption and digestion. 27, STRUCTURAL COMPLEXITY OF SEAGRASS INFLUENCES PATTERNS OF RECRUIT- MENT OF FISHES IN SAN DIEGO BAY Lipski, D.M. San Diego State University, San Diego, CA 92182 Processes affecting recruitment are important determinants of population structure and dynamics in marine fishes. Habitat structural complexity may influence recruitment success by providing refuges from predators, enhancing food availability, and influencing settlement by moderating current flow or velocity. The goal of this project was to determine how differential structural complexity of the eelgrass Zostera marina, an abundant habitat in San Diego Bay, influenced recruitment of fishes. We cross- factored shoot density with shoot height with standardized habitats in deploying artificial seagrass units (ASUs) at several sites within the bay. Recruits of all fishes were collected after 2-wk periods in each of 5 trials. Approximately 250 recruits from 12 species were collected. Recruitment among the six more abundant species revealed differential responses to habitat structural compiexity, with 26 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES recruitment varying with shoot height, shoot density, and with no difference among treatments. We also conducted an experiment to determine whether predators moderated the abundance of recruits in treatments of predator access and exclusion, using a standardized shoot height and density. There was no significant difference in recruitment to predator access, predator exclusion and cage control treat- ments. Taken together, the results of these experiments reveal species-specific responses to seagrass habitat structural complexity that appears to be more a result of habitat selection than post-settlement predation. 28 TRANSITIVITY AND SONG PREFERENCES IN THE HOUSE CRICKET, ACHETA DO- MESTICUS Sean E. Walker! and J. Andrew Roberts’. 'Department of Biological Science, California State University Fullerton; 7Department of Evolution, Ecology, and Organismal Biology, The Ohio State University, Newark Understanding how animals choose between alternative options is a fundamental problem in be- havioral ecology. Traditionally, models of decision-making utilized in animal behavior have assumed rationality and value maximization. In other words, individuals have complete ranking of all of their options and have infinite processing time and power to differentiate among them. Few, if any, studies have examined if these assumptions hold in the context of mate choice and none have been done utilizing invertebrates. Male crickets utilize relatively simple signals made up of repeated pulses of sound to attract females. In this study, we tested the hypothesis that female Acheta domesticus exhibit transitivity with regard to song choice. That is, given that a female prefers song a to song b and song b to c, they should prefer song a to song c. We tested this hypothesis using a binary choice apparatus and 3 songs that differed in the number of pulses per chirp and chirp rate. We tested the preference of individual females for song | versus song 2, song | versus song 3 and song 2 versus song 3. Females generally preferred songs with higher chirp rates but female choices did not exhibit transitiv- ity. That is, an individual females preference for one song over another could not be predicted based on previous choices. These data suggest that females are not utilizing a decision-making process grounded in principles of value maximization and rationality as has been previously assumed. 29 ACOUSTIC TRACKING AND MONITORING OF CULTURED JUVENILE WHITE SEA- BASS RELEASED INTO SOUTHERN CALIFORNIA EMBAYMENTS M. A. Shane', M. A. Drawbridge', and H. C. Simonds’. 'Hubbs-SeaWorld Research Institute, 2595 Ingraham Street, San Diego, CA, 92109; ?San Diego State University Foundation, 5250 Campanile Drive, San Diego, CA 92182 Since 1986 over one million cultured white seabass, Atractoscion nobilis, have been tagged and released in southern California as part of the Ocean Resources Enhancement and Hatchery Program. Just over 1,200 of these fish have been recovered through various sampling methods. However, only limited information regarding the short term movement patterns and survival of cultured seabass is known from these results. To increase our understanding of these processes, we surgically implanted acoustic pingers in the peritoneal cavity of 58 cultured white seabass (X SL = 27 cm) during the past three years. After surgery, fish were held in captivity for 2—5 weeks to assess their healing prior to release. Acoustically tagged seabass were released as part of a larger group of cultured fish into several embayments within southern California. The fish were tracked actively from a small vessel and pas- sively using an array of moored hydrophones. Emigration rates from embayments ranged from 37 to 57%, with most of these individuals leaving the embayment by the fifth day after release. Mortality rates were inferred from tags recovered from the sea floor. Mortality during the first month following release ranged from 20 to 40%. Strong circumstantial evidence suggested that top predators of cultured white seabass include birds, harbor seals, and octopuses. Of the seabass that were last heard from in embayments, 26 % were ultimately unaccounted for. 30 LACTATE PROCESSING IN ENDOTHERMIC AND ECTOTHERMIC SHARKS J.-M. Backey and K.A. Dickson. California State University, Department of Biological Science, Fullerton, CA 92831 When sharks burst rapidly for prey capture or predator avoidance they undergo anaerobic metab- olism in their fast-glycolytic white muscle (WM), producing lactate. The endothermic mako shark has a higher capacity to produce lactate than the ectothermic leopard shark; therefore it should process ABSTRACTS Di] lactate at a higher rate. There is evidence that most of the lactate is reconverted to glycogen within teleost fish WM, but lactate processing has not been examined in sharks. The shortfin mako shark (Isurus oxyrinchus) was compared with the leopard shark (Triakis semifasciata) to test the following hypotheses: (1) the mako shark will have higher activities of enzymes required for glycogen synthesis (pyruvate carboxylase-PC, phosphoenolpyruvate carboxykinase-PEPCK, malic enzyme-ME, and fruc- tose-1,6-bisphosphatase-FBPase) in WM than the leopard shark and (2) within each species, activities of these enzymes will be higher in WM than in liver, heart, or red muscle. Lactate dehydrogenase activity (an index of lactate production) in WM was higher in the mako than in the leopard shark, as expected. Neither PC nor PEPCK activity was detected in WM, and there were no significant inter- specific differences in FBPase or ME activity. PEPCK activity in liver was significantly higher in the mako. The only significant difference among tissues was that mako PEPCK was higher in the liver than in the heart. Therefore, neither hypothesis was supported. The results indicate that glycogen synthesis from lactate within WM in these sharks cannot occur unless an alternative route for pyruvate to phosphoenolpyruvate exists. 31 LATE PREHISTORIC CERAMIC PRODUCTION IN THE UPPER MOJAVE RIVER RE- GION, SAN BERNADINO COUNTY, CALIFORNIA B. Travis. California State University, Department of Anthropology, Fullerton, CA 92831 Petrographic analysis of twenty-five ceramic sherds from the Deep Creek and E.S. Young sites, located in the upper Mojave Region of southern California, was undertaken in order to test the as- sumption that brown wares were locally produced and not intrusive in archaeological assemblages of the late prehistoric period in Southern California. Mineralogical analysis of ceramic thin sections, and samples of clay, sand, and gravel from the catchment areas surrounding the sites, allowed for the distinction of local versus non-local ceramic products. Results indicate that brown ware ceramics recovered from both sites were likely produced in the immediate vicinity of the sites and that these brown wares have unique characteristics which distinguish them from other brown wares found in southern California. No definite location of manufacture of buff wares could be determined, indicating that they may have been imported from another region. 32 ARCHAEOFAUNAL RESEARCH AT LATE HOLOCENE PREHISTORIC SITES ON SAN NICOLAS ISLAND: RECENT EXCAVATIONS AND EXPERIMENTAL STUDIES Steven R. James and James R. Wallace. Department of Anthropology, California State Univer- sity at Fullerton, PO. Box 6846, Fullerton, CA 92834-6846 Results of recent archaeofaunal research from two late Holocene prehistoric sites in the Central Plateau of San Nicolas Island are presented. During fall 2004, test excavations were conducted at CA- SNI-44 by a field class from the Department of Anthropology at CSUEF Although earlier archaeologists thought the site had been essentially destroyed by construction activities on the island, our recent excavations indicate that intact prehistoric cultural deposits are present, including well-preserved fish and marine mammal remains. Archaeofaunal investigations at another nearby site on the Central Plateau, that of CA-SNI-102, are also discussed. As a means of explaining the burning patterns ob- served on fish remains at CA-SNI-102 and other prehistoric sites on San Nicolas Island, an experi- mental study of fish processing and cooking was conducted, the results of which are presented. Future directions of the archaeofaunal research at these two sites and their implications for understanding overexploitation and resource depression in the late Holocene are discussed. 33 ARCHAEOLOGY AT THE HARVARD HILL SITE, SAN BERNARDINO COUNTY, CAL- IFORNIA J.A. McKenna. McKenna et al., Whittier, CA. 90601-3724 McKenna et al., under the direction of the San Manuel Band of Mission Indians, Highland, has been working on the Harvard Hill archaeological site in San Bernardino County. The site is a large, prehistoric occupation area yielding dates of 600 + 30 years B.P. (ca. A.D. 1400) and representing an extensive scatter of materials indicative of a trade center with multiple occupations. Materials recov- ered from the site include shell, alphaltum and lithic materials associated with coastal California as well as projectile points, ceramics, and other items indicative of eastern California (the Mojave Desert 28 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES and Great Basin), indicating an extensive array of items representing virtually all areas of Southern California. This site, in conjunction with other well documented sites in the area of Barstow and the Mojave River, is evidence that an elaborate trade system existed in the area of the Mojave Desert while other areas of the greater Southwest were experiencing a significant decline in population and exchange. 34 TWO RITUAL CACHES FROM CA-ORA-950: A WINDOW ONTO THE SYMBOLOGY OF COGGED STONES H. C. Koerper. Cypress College, Cypress, CA 90630 Within single cogged stone caches, two cogged stones with identical counts of cogs constitute a ‘““matched pair.”’ Three matched pairs were identified for two cogged stone caches at a Lake Forest, Orange County site. One of these caches also contained an elongate artifact that is probably a fertility/ fecundity symbol. The CA-ORA-950 evidence, coupled with that of three caches from two other sites, supports the hypothesis that regional Early Holocene iconography embraced dualistic symbology. 35 PREHISTORIC ADAPTATIONS TO COASTAL WETLANDS: AN 8,000 YEAR VIEW FROM SANTA MONICA BAY, WEST LOS ANGELES John G. Douglass, Jeffrey H. Altschul, Richard Ciolek-Torrello, Benjamin R. Vargas, and Donn R. Grenda. Statistical Research, Inc. 21 West Stuart Ave Redlands, CA 92373 For over 8,000 years, aboriginal peoples have lived and adapted to the changing environments of the Ballona Lagoon, a drowned river valley located on Santa Monica Bay, West Los Angeles. During this time, the coastal environment, including the Ballona Lagoon itself, has altered significantly with resulting changes in human behavior. This, in addition to a melding of cultural traditions from both the coast and desert, led to a complex social dynamic that flourished in the Los Angeles Basin. Research by Statistical Research, Inc. (SRI) and others at nearly 25 archaeological sites in the Ballona region offers a unique view into human adaptations to coastal wetlands. 36 OPTIMAL RESOURCE PRODUCTION: A MODEL OF CHUMASH IMPACT ON THE EN- VIRONMENT IN THE SANTA BARBARA CHANNEL AREA Edgar H. Huerta. Department of Anthropology, California State University, Fullerton, 800 N. State College Blvd, Fullerton, CA 92831 The management of natural environments to reach an optimal level of resource production represents a concept that induces archaeologists to generate new interpretations of past cultural depositions. Among these interpretations, prehistoric societies positive/negative impact on the environment along the California Coast present the Chumash as a possible model group for the study of such impacts. The prehistoric long habitation span and high population density of the Chumash along the Santa Barbara Channel coastal area provide evidence in support of a well developed natural resource man- agement program. Using archaeological and ecological applications, this paper presents a possible optimal resource production model for an understanding of Chumash relationship with their environ- ment. Within this model, prehistoric Chumash populations appear as colonizers of various micro- ecosystems within their geographic area. These areas, previously disturbed only by natural successions, offered the Chumash a large variety of resources. The optimal resource production model, in com- bination with middle Holocene archaeological evidence, provides a way for studying the maximization of natural resources and their negative/positive impacts on the environment. Attention is given to the climatic changes during the middle Holocene period along the Santa Barbara Channel area and the switch to a more intensified use of land resources. Climatic fluctuations in combination with the use of fire to maximize land resources appear to explain the Chumash impact on the environment within the optimal resource production model. 37 “JUNE GLOOM” AND “TULE FOG”: CONSIDERATIONS OF THE IMPORTANCE OF CLOUD MOISTURE FOR PREHISPANIC SETTLEMENT AND SUBSISTENCE STRATE- GIES IN SOUTHERN CALIFORNIA Frederick W. Lange, PhD. LSA Associates—Riverside Office In 1965, Edward P. Lanning published the volume Peru Before the Incas. This landmark work clearly established the importance of “‘lomas agriculture’’ (the subsistence practices based on vegetative is- ABSTRACTS 29 lands formed with coastal fog moisture) as one of the principal features of early human sedentism and the basis for further cultural development on the Pacific coast of Peru. Although similar fog moisture conditions exist on the Pacific coast and in some inland valleys (San Joaquin and Sacramento) of California, their potential importance for affecting prehispanic settlement and subsistence has been generally overlooked. This paper summarizes available climatic and archaeological data from two distinct locations (1) the southern coastal Orange County region, and the (2) more inland San Joaquin and Sacramento Valley regions. On the basis of these preliminary analyses, this paper concludes that the data indicate that, as in Peru, fog moisture played a significant, if geographically limited, role in prehispanic California. Archaeologists conducting research in California are encouraged to integrate theoretical and methodological considerations of fog moisture adaptation with future research and interpretation. 38 PALEOCLIMATE AND VEGETATION RECORD IN THE LATE PLEISTOCENE PALOS VERDES FORMATION (“OLDER ALLUVIUM’’) IN THE SAN FERNANDO VALLEY, SOUTHERN CALIFORNIA L.H. Fisk. PaleoResource Consultants, 5325 Elkhorn Boulevard, #294, Sacramento, CA 95842 Microfossil samples collected from a 50-foot section of Palos Verdes Formation (“Older Alluvium”’ ) exposed in excavations near “beautiful downtown Burbank” have produced an unusual Late Pleis- tocene pollen and spore flora. Surprisingly, the dominant palynomorphs in almost all samples are fern and club moss spores (>40%), followed by pollen of Compositae (~ 10%), and alders (~5%); all three of these plant groups are common pioneer species colonizing ecologically disturbed areas. This unusual pollen and spore assemblage appears to record ecological disturbance due to glacio-eustatic sea level fluctuations. These fluctuations may have resulted in a rather wide coastal plain with frequent pertur- bations to the local vegetation. The frequency of disturbances favored opportunistic species that could invade open habitats and reproduce rapidly and prevented the development of ecological climax for- ests. Samples from a depth of 46—48 feet and from a paleosol at approximately 4—6 feet appear to represent more mature or climax plant communities with greater diversity and more tree species. The palynoflora from these samples include plant species whose modern equivalents live along the coastal summer fog belt in northern California. These modern occurrences suggest that the Late Pleistocene maritime climate that characterized the area was cool, wet, and less seasonal or more equable, in sharp contrast to the strongly seasonal Mediterranean climate with hot, dry summers and warm, wet winters that exists in the region today. Thus, the portion of the Palos Verdes Formation stratigraphic sequence sampled was probably deposited during a glacial-pluvial (cool rainy) stage of the Late Pleistocene. 39 REVISED CORRELATION AND AGE ASSIGNMENTS OF FOSSIL LAND MAMMAL AS- SEMBLAGES OF LATE HEMINGFORDIAN TO EARLIEST HEMPHILLIAN (EARLY MID- DLE TO EARLY LATE MIOCENE) AGE IN CALIFORNIA, NEBRASKA, AND TEXAS, BASED ON OCCURRENCES OF TICHOLEPTINE OREODONTS (MAMMALIA, ARTIO- DACTYLA, OREODONTIDAE, TICHOLEPTINAE) AND OTHER LAND MAMMAL TAXA E.B. Lander. Paleo Environmental Associates, Inc., 2248 Winrock Avenue, Altadena, CA 91001-3205 The Green Hills Fauna (F) (low. Resistant Breccia Member [RBM], Barstow Fm. [BF], CA) contains Brachycrus laticeps, correlates with the Sheep Creek (type Hemingfordian [He]) and Low. Snake Creek Fs of NE, and is late He, not early Barstovian (Ba). The Second Division F (up. RBM) is latest He. The overlying Low. (type Ba) Barstow F (low. Fossiliferous Tuff Member [FTM], BF) contains endemic Mediochoerus mohavensis mohavensis (not Merychyus medius ?}schrammi) and is early (not late) Ba, while the late Ba, Up. Barstow F (up. FTM) includes the first appearance of the cricetine Copemys russelli. The latter three Fs lack definite correlatives in NE. The Ustatochoerus profectus (= M. medius)/C. russelli Assemblage Zone (AZ) (Dove Spring Fm. [DSF] Member 2, CA) contains M. m. compressidens, correlates with the Minnechaduza F of NE, and is early Clarendonian (Cl), not late Ba. The latter F overlies the Devil’s Gulch EK which contains large M. m. medius and correlates with the earliest, type Cl, Low. Clarendon F of TX. The low. Cupidinimus avawatzensis/Paracosoryx furlongi AZ (DSF Member 3) contains M. major santacruzensis, is early late (not early) Cl (pre- Cerrotejonian), and correlates with the Xmas-Kat Local (L)F of NE. The low. (but not basal) Paronych- 30 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES omys/Borophagus littoralis AZ (DSF Member 6; contains Hemphillian [Hh] index taxon/antilocaprid Ilingoceros) and the Kendall-Mallory LF (Orinda Fm., CA) contain M. ma. ?profectus and the cricetine Paronychomys, correlate with the Snake Creek F of NE (contains M. ma. ?profectus and megalonychid sloth), and are earliest Hh (post-Montediablan), not late Cl. 40 CACHE OF FOSSIL REMAINS FOUND IN SAN QUINTIN, BAJA CALIFORNIA LOCATED WITHIN A BEACH CLIFF CAVE G. Pacheco-Ambriz. Baja California Independent Research Project, Pasadena City College, De- partment of Natural Science, Pasadena, CA, 91003 An ongoing multi-disciplinary cave excavation, located 11 meters above sea level in San Quintin, Baja California, has revealed a variety of faunal remains. The cache includes predominantly carniv- orous mammalian species: puma, Felis concolor, coyote, Canis latrans, grey fox, Urocyon ciner- eoargenteus, sea otter, Enhydra lutris and ringtail, Bassariscus astatus. Other mammals found in the cave consist of kangaroo rat, Dipodomys agilis, and two rabbit taxa: Sylvilagus sp.and Lepus califor- nicus. In addition, the remains of three species of bird and a whale are represented though yet to be definitively identified. The explanation for the presence of such a diverse collection of faunal remains in one isolated beach cliff cave can be hypothesized by applying a plausible anthropological construct to the data. The indigenous group, Kiliwa, historically established themselves in the San Quintin region approximately 1000 AD. As a seasonal nomadic group, they moved across Baja California’s high sierras, San Pedro Martir, and possibly the Gulf of California. Certain animals that were found in the cave were seized and possibly killed in the high sierras, and were then transported to the cave by the Kiliwa people, for ceremonial rituals conducted by Kiliwa shamans. 41 ADSORPTION OF SYNTHETIC PYRETHROIDS ON SEDIMENT S. Bondarenko, S. Qin and J. Gan. Department of Environmental Sciences, University of Cal- ifornia, Riverside, CA 9252] Adsorption on sediment regulates the fate and bioavailability of contaminants in the aquatic envi- ronment. A common way to measure adsorption capacity of organic compounds in soil or sediment is to use the batch equilibration—solvent extraction method in which the solid and aqueous phases are separated by centrifugation and the aqueous phase concentration C,, is determined after exhaustive solvent extraction. However, this method may give artificially depressed K, for strongly adsorbing compounds such as pyrethroids, as small colloidal particles and dissolved organic matter are not eliminated from the aqueous phase and contribute to the measured C,,. Solid phase microextraction (SPME) selectively detects the freely dissolved concentration and thus may be used to improve K, measurement. We determined K, values for eight pyrethroid insecticides using both solvent extraction and SPME to measure C,,. K, obtained with SPME was 2—100 times greater than that with the solvent extraction method, and the difference was more significant for sediments with higher organic matter content. K, measured with SPME is expected to be useful for predicting the bioavailability or toxicity of sediment-borne pyrethroids, as it correlates with the free or bioavailable concentration. 42 SURVEY FOR SYNTHETIC PYRETHROIDS WITHIN THE SAN DIEGO/NEWPORT BAY WATERSHED R.L. Budd, S. Bondarenko, and J. Gan. University of California at Riverside, Riverside, CA O2an The Upper Newport Bay is an ecological reserve located within Orange County, CA. It is a marine estuary that provides habitat for nearly 200 species of birds, and several species of fish, mammals and native plants. The primary freshwater inlet for the estuary is the San Diego Watershed, which is the primary drainage area for the cities of Santa Ana, Tustin, Lake Forest and Irvine. With the increasing encroachment of urban sprawl, there has been a dramatic shift in land use within the San Diego Watershed from agricultural to urban landscapes. There is a concern that this shift in land use will result in an increase of non-source pollution from individual homesteads that use pesticides to aid in ant and weed control. The use of pyrethroids has increased steadily in both agricultural and urban settings as a replacement for organophosphate insecticides. In addition, nursery use has also increased drastically since 1995 as mandated for red and imported fire ant quarantine. Pyrethroids commonly ABSTRACTS 3] have high aquatic toxicity, and contamination of surface streams by pyrethroids is of concern. The objective of this study was to determine the presence and spatial variability of pyrethroids within the watershed. Eighteen sediment grab samples were taken from locations within the watershed. Five of the samples were collected at the outlets of existing nurseries. The rest were collected within drainage channels and Upper Newport Bay. Samples were analyzed for pyrethroids using GC-ECD. The fre- quency, location, and levels of pesticide detections will be presented at the meeting. 43 THE EFFECT OF FEMALE CHEMICAL CUES ON THE AGGRESSIVE BEHAVIOR OF MALE CRICKETS, ACHETA DOMESTICUS Leslie J. Buena and Sean E. Walker. Department of Biological Science, California State Uni- versity, Fullerton, Fullerton, CA 92831 Male crickets, Acheta domesticus, show aggressive behavior to gain opportunities for reproduction over other males. Female crickets show a preference towards more aggressive and larger males. Female chemical cues along with residency status should influence male aggression. We hypothesized that aggression would increase with higher levels of female cues and that residents should be more likely to exhibit aggression in the presence of female cues than in their absence. We observed male fights in 14 cm X 26 cm containers with a sand substrate. These containers had previously housed no females, one virgin female, or two virgin females for 48 h prior to the trials. We found no effect of female chemical cues on the amount of aggression. Chemical cues also had no influence on the aggressive behavior of the resident or intruder. We also found that resident status, weight differences, or age differences between residents and intruders did not predict the outcome of the interactions. We did find that the intensity of aggression could be predicted based on the age of resident and intruder males. Older residents and younger intruders were more likely to be aggressive. Our results suggest that residency status and perceived territory quality do not influence aggressive interactions in male house crickets. In addition, these data suggest that age and residency status may be important factors influ- encing a male’s decision to fight. We hypothesize that this pattern is a product of younger intruders having nothing to lose and the cost of territory loss for older residents. 44 THE EFFECTS OF ARTICHOKE THISTLE (CYNARA CARDUNCULUS) DENSITY AND COASTAL SAGE SCRUB INFLUENCE ON PREDATION OF ARTIFICIAL NESTS Andres Carrillo and Leslie Buena. Department of Biological Science, California State Univer- sity, Fullerton Artichoke thistle, Cynara cardunculus, is an invasive plant in California grasslands listed on the noxious weed index of the California Department of Food and Agriculture. It may affect native primary producers and consumers, but its invasion impact has not been fully studied. Thistle invasion changes the habitat structure, thus changing the niche composition. Birds may utilize the flower stalk of this exotic plant as a nesting resource. Thistle may impact nest success by providing camouflage from avian predators for birds nesting in grasslands. A comparison of artificial nest survival was made between thistle invaded grassland and grassland with almost no thistle. We hypothesized that higher nest success would occur with nests in thistle invaded grasslands than in grasslands without thistle, and that artificial nest success would be higher with increasing distance away from the surrounding coastal sage scrub habitat. Twenty nests were placed in each type of grassland at 45 m intervals from coastal sage scrub into the transition of grassland. Each nest was baited with one quail egg and two clay eggs. Predation on the nests was checked at 40 and 110 hours. A nest was noted successful if no eggs were disturbed. More nests were successful in grassland invaded with the thistle (60% success) then in grassland without thistle (40% success). Also, nest success rate increased with distance from coastal sage scrub. Comparing artificial nest survival in artichoke thistle invaded grasslands provides a greater understanding of the impacts of artichoke thistle on the habitat it invades. 45 SEWAGE IS AN UNLIKELY SOURCE OF FECAL INDICATOR BACTERIA IN THE LOW- ER SANTA ANA RIVER WATERSHED D.L. Young', J. A. Noblet*, E. Y. Zeng!’ and S. Ensari’. 'Southern California Coastal Water Research Project, Westminster, California; California State University, San Bernardino, Cali- fornia; *University of California, Irvine, California The Santa Ana River, CA and adjacent wetlands have been identified as potential sources of fecal indicator bacteria (FIB) to the surf zone at Huntington Beach CA. Fecal steroid chemical markers including coprostanol, epicoprostanol, cholesterol, cholestanol, a-cholestanone, B-cholestanone, {-si- SOUTHERN CALIFORNIA ACADEMY OF SCIENCES ie’) i) tosterol, stigmasterol, stigmastanol, campesterol, and caffeine were extracted by solid phase extraction (SPE) and supercritical fluid extraction (SFE). The results of these analysis and multivariate statistic were used to examine whether sewage was a significant source of FIB within the Santa Ana River watershed. A difference was found in steroid ratios between river samples, raw and treated sewage from a local treatment plant, or nearby effluent plume. The characteristics of the steroid ratios coupled with the strong correlation between coprostanol and turbidity suggested a diagenetic rather than a biogenic source for the coprostanol in the samples. Additional multivariate statistical analysis showed that the concentrations of FIB were better correlated with bird fecal steroids than with typical sewage steroids. 46 DESCRIPTION OF FIELD-COLLECTED LARVAE OF TWO NATIVE FRESHWATER SOUTHERN CALIFORNIA FISHES, CATOSTOMUS SANTAANAE AND GILA ORCUTTI Richard F. Feeney, Natural History Museum of Los Angeles County, 900 Exposition Blvd., Los Angeles, CA 90007; and Camm C. Swift, ENTRIX, Inc., 2140 Eastman Ave., Suite 200, Ven- tura, CA 93003 Larval series of the Santa Ana sucker (Catostomus santaanae, Federally Threatened) and arroyo chub (Gila orcutti, California Species of Special Concern) are described from specimens collected from the Los Angeles and Santa Ana river drainages. Catostomus santaanae larvae are elongate. They have 41—46 myomeres and a distinctive paired-triangle patch of melanophores over the midbrain. Melanophores are present on the snout, dorsal body, lateral line, dorsal gut, post-anal ventral body and caudal fin. Pre-anal length equals 74—79% SL, typical of catostomids. Gila orcutti larvae are relatively deep-bodied. They have 36—39 myomeres and a distinctive heart-shaped patch of melano- phores over the midbrain with a line of melanophores trailing posteriorly. Heavy pigment is present on the snout, lower jaw, dorsal body, lateral line, gill arches, dorsal gut, post-anal ventral body and caudal fin; they have a shorter pre-anal length of 65—72% SL, typical of cyprinids. These two species often occur together, and less commonly with the local native form of Rhinichthys osculus (another cyprinid that is a California Species of Special Concern). Characters distinguishing the three from each other and from other local freshwater fish larvae are discussed along with habitat preferences. 47 AXIAL SPLITTING OF SHRUBS IN WET AND DRY ENVIRONMENTS C. Goedhart, G. Pongetti, S. Espino, J. Schenk. California State University, Fullerton, Depart- ment of Biology Arid regions around the globe are dominated by shrubs of a unique growth form. They possess segmented woody roots and stems that split apart with maturity, often resulting in complete fragmen- tation. These species are often dominant in their native habitats and include Larrea tridentata and Ambrosia dumosa in North America, Zygophyllum dumosum and Artemisia herba-alba agg. in Israel, as well as numerous Artemisia species in the northern hemisphere. Many other species posses strongly fluted or segmented axes, but do not physically split apart. Morphological stem segmentation causes axial segmentation of the hydraulic system. Previous research has shown that woody plants from dry environments show a high degree of hydraulic segmentation of the wood, even if they show no signs of morphological stem segmentation. We postulate that axial hydraulic segmentation introduces re- dundancy into the hydraulic system, increasing survival of the whole genetic individual, but at the cost of losing parts of the plants to drought-induced mortality. We hypothesized that the degree of hydraulic redundancy in shrubs will decrease along aridity gradients from arid to mesic conditions. To test this hypothesis, we documented the prevalence of morphological axis segmentation in shrubs from a variety of genera along North and South American aridity gradients located between 30° and 35° latitude. Along the same gradients we also measured axial hydraulic segmentation at the anatomical level by mapping pathways of water transport in the xylem using injected dye tracers. The results support our hypothesis that hydraulic redundancy in shrubs decreases from arid to mesic environments. ABSTRACTS oS) (Ge) 48 EVALUATION OF METHODS FOR DETERMINING CHRONIC TOXICITY IN MARINE SEDIMENTS D. Greenstein’, S. Bay', B. Anderson’, B. Phillips?, G. T. Chandler, D. Farrar+, A. H. Ring- wood?, and C. Keppler®. ' Southern California Coastal Water Research Project, Westminster CA; * University of California Davis, Monterey, CA; *University of South Carolina, Columbia, SC; *US Army Engineer Research and Development Center, Vicksburg, MS; *University of North Carolina—Charlotte, Charlotte, NC; “Marine Resources Research Institute, Charleston, SC Sediment quality objectives are being developed in the State of California that are expected to include measurements of acute and chronic sediment toxicity. Acute sediment toxicity methods are commonly used, however chronic testing methods have been used on a much more limited basis in California. This study was designed to compare between several available chronic sediment toxicity protocols and guide the selection of methods for use in California. Sediment samples were collected from bays and estuaries in the Southern California Bight and from San Francisco Bay. Split samples from 15 stations were distributed to four laboratories for testing using six methods: a sediment-water interface method with sea urchin (Strongylocentrotus purpuratus) or mussel (Mytilus galloprovincialis) embryos; a benthic copepod (Amphiascus tenuiremus) life cycle test; a polychaete (Neanthes arena- ceodentata) survival and growth test; an amphipod (Leptocheirus plumulosus) survival, growth and reproduction test, a larval clam (Mercenaria mercenaria) survival and growth test; and an oyster (Crassostrea virginica) lysosomal destabilization assay. In addition, each station was an also tested using acute methods with two species of amphipod (Eohaustorius estuarius and Leptocheirus plu- mulosus). Sediment metals, organics, and grain size were analyzed for each station. There was a wide range of results for the samples with between 8 and 80% of the stations being found to be toxic by any given protocol. Each station was found to be toxic by at least one method and no station was found to be toxic by more than five of the six chronic methods. The Eohaustorius acute, copepod reproduction, and polychaete growth endpoints had the strongest correlations with sediment chemistry, but also correlated strongly with sediment physical parameters. 49 LACK OF GENDER-BIASED MICROSITE PATTERNS IN SALIX LASIOLEPIS Shannon Harsh and Allison Roth, Dustin Taylor and Cheryl Swift. Whittier College, Department of Biology, Whittier, CA 90608 Previous studies on dioecious plants have demonstrated differences between male and females in terms of the microsites they inhabit. Reported trends in microsite inhabitation for dioecious plants have been that females inhabit moister habitats than males, seemingly to offset reproduction costs. In this study we looked at the distribution of sexes of Salix lasiolepis in a .15 mile reach of the Tujunga River in the San Gabriel Mountains (California) in relation to the thalweg of the streambed. We also focused on the relationship of wood density versus sex in S. /asiolepis and as a function of current, as well as xylem to lumen ratio versus sex. Based on previous research, we expect to find that female S. lasiolepis inhabiting microsites closest to the thalweg and females would exhibit lower wood den- sitfes and therefore greater xylem to lumen ratios than males. However, preliminary results indicate that there are no differences in the distribution of males and females in regards to elevation from the thalweg, wood density of males and females and in xylem to lumen ratios in Salix lasiolepis. This could be due to two potential reasons. One is because low summer discharge in the Tujunga River places individuals under water stress, regardless of where they occur in the stream channel, and therefore, rely more on ground water than on surface water. The second explanation is that because freezing places an upper limit on xylem conduit diameter for individuals in the channel, increases in vessel diameter that would lead to lower wood density does not occur. 50a MORPHOLOGY AND MOLECULAR PHYLOGENY OF EGREGIA MENAZIESIT Henkel, S.K., G.E. Hofmann, and A.C Whitmer. Marine Science Program, Department of Ecol- ogy, Evolution, and Marine Biology, University of California, Santa Barbara 93106 The morphology of the feather boa kelp, Egregia menziesii, varies considerably throughout its range from Canada to Baja California, México. These traits may be genetically fixed or be indicative of a high degree of plasticity. We characterized the distribution of Egregia morphotypes at two sites in Oregon and seven in California. Results show variation in the laterals and rachis corresponding with 34 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES latitude, and all populations showed a transition of lateral type with increasing length as has been previously reported. Sequence differences between Oregon and southern California populations are present in the internal transcribed spacer region between the 26s and 5.8s rDNA genes. This genetic investigation provides baseline data for studying plasticity in temperature tolerance, in terms of heat shock protein (Hsp) production, within and among species over large geographic ranges. Hsps are also produced in response to stressors such as hypoxia, metal ion concentration, and organic com- pounds. This project will lay the groundwork for using Hsps to study tolerances to climate change and anthropogenic stressors in seaweeds. Additionally, physiological comparisons in response to ther- mal stress between native species and competitive invaders may help determine if thermal microhab- itats facilitate invasions. Since high temperature stress has led to the decline of native kelps in southern California, knowledge of the temperature tolerances and physiological responses of native and invasive kelp species can contribute to efforts for conservation and restoration projects. 50b BIOAVAILABILITY OF PERMETHRIN IN SEDIMENTS AND ESTIMATED WITH SOLID PHASE MICROEXTRACTION (SPME) W. Hunter, W. Yang, and J. Gan. University of California, Riverside, Riverside, CA 92521 The use of synthetic pyrethroid insecticides (SPs) is increasing in agriculture and urban environ- ments. A recent survey showed that SPs were commonly found in aquatic sediments in the Central Valley of California. Therefore, it is imperative to understand the ecotoxicological implications of SPs in the sediment environment. However, because pyrethroids have a high affinity for sediment and dissolved organic matter, their bioavailable concentrations in sediment systems are expected to be significantly lower than the total sediment concentration. Therefore, their sediment toxicity cannot be evaluated based on the whole sediment concentration. In this study, the bioavailability of permethrin to Chironomus tentans larvae in water-sediment systems was investigated. During the bioassays, poly- dimethylsiloxane (PDMS) fibers were used as a “‘biomimetic’ freely dissolved concentration of SPs in water-sediment systems. The concurrent analyses facilitated 5 tool to simultaneously measure the understanding of the relationship between pesticide phase distribution and the biota sediment accu- mulation factors (BSAF) with different sources of sediment. Generally, larvae accumulated more pesticide in sandy sediment than silt or clay sediments. The amount of chemicals accumulated on the PDMS fiber was well correlated with body residues. This suggests that chemical partitioning into PDMS ‘“‘mimics”’ the bio-uptake process and PDMS fiber may serve as a good surrogate for sediment biota. 51 PRELIMINARY ANALYSIS OF A CAVE FAUNA FROM SAN QUINTIN, BAJA MEXICO A J. Jenkins. Baja California Independent Research Project, Pasadena City College, Department of Natural Science, Pasadena, CA 91106 Preliminary identification of fauna from an ongoing multi-disciplinary cave excavation has revealed puma, Felis concolor, coyote, Canis latrans, grey fox, Urocyon cinereoargenteus, sea otter, Enhydra lutris, ringtail, Bassariscus astutus, the epiphysis of a large whale vertebra and multiple elements of a large aves. Most of these taxa occur in the San Quintin Valley area today though perhaps not in the immediate vicinity of the coast. Exceptions are the sea otter which was extirpated in 1922 (last historical record) and possibly the large bird bones and whale epiphysis which have yet to be defin- itively identified. The cave is located in a basalt cliff 11 meters above sea level in the vicinity of Bahia de San Quintin approximately 485 kilometers south of San Diego, Ca. on the Pacific coast. It was formed by a lava tube and has the general dimensions of 1.8 meters high, 2.0 meters wide and tapers to a length of 7 meters. The floor sediment consists of quartz- and feldspar-rich aeolian deposited sand. Similar sand covers much of the cliff-top in the form of dunes 10—20 meters in depth. Previous activity by locals had disturbed the sediments, likely revealing bones in the past. The initial assumption was that all sediments had been repeatedly disturbed. However, test excavation begun in November 2004 revealed abundant skeletal material approximately 15—30 centimeters below the present sediment surface. ABSTRACTS Uo Nn 52 BOLUS REBOUND KINEMATICS DURING ENGULFMENT FEEDING IN THE ROR- QUAL WHALES B.W. Kot. Department of Ecology and Evolutionary Biology, UCLA, Los Angeles, CA 90095 Rorqual whales (Family: Balaenopteridae) employ unique filter-feeding structures and techniques to controllably engulf massive amounts of prey-laden seawater while feeding. Engulfed water containing a concentration of prey items forms a bolus that enters the whales’ distensible ventral pouch through the buccal cavity. The two-dimensional kinematics of this bolus was analyzed using digital video from three species of surface-feeding rorqual whales in the Gulf of St. Lawrence, Canada. Individual still frames were extracted from video sequences and landmarks were placed on consecutive frames to calculate movement, relative to the animal, of the bolus over 1/30 second frame intervals. The bolus initially translated posteriorly inside the ventral pouch then rebounded off the posterior end of the pouch before traveling back toward the buccal cavity. Velocities and directional changes were quan- tified, and the momentum of the bolus is thought to help initiate the ram filtration process through the baleen plates. Results showed that Balaenoptera acutorostrata has the fastest bolus rebound velocity, followed by B. musculus and B. physalus, respectively. Further work will be performed to help un- derstand the implications of these findings, including how they contribute to scaling relationships between the sizes of the different species and the volumes of the boluses. 53 THE GREATEST GRUNION HUNT IN 50 YEARS: CALIFORNIA GRUNION SIGHTINGS ACROSS THE SEASON AND ALONG THE COAST IN 2004 K. Martin, B. Cupp, and P. Johnson. Pepperdine University, Malibu, CA 90263-4321 California grunion are marine silversides that appear on sandy beaches in the middle of the night for spawning runs. Their populations are difficult to assess because they rarely come up in trawls, they do not take a hook, and they are almost never seen except during their spectacular midnight runs. Recently we developed a method for training citizen scientists to assess grunion runs in widely dis- persed areas and to report them instantly to a central database via an internet-based interface. A series of workshops were held in spring of 2004 to train over 350 volunteer Grunion Greeters from four coastal counties. Runs were monitored on 30 specific beaches from San Diego to Monterey Bay over the course of the closed season (April and May), and early June, for a total of 10 nights. Runs were assessed according to the Walker Scale for strength and duration. Runs were highly variable in space and time. We show data for grunion populations across the spawning season and along the coast to examine possible patterns. Although these data are only one year’s effort, the number of dates and beaches represented make this the most ambitious assessment of the California grunion spawning population ever attempted. 54 INTERACTIONS OF NEARSHORE FISH ASSEMBLAGES AND NET-PEN MARICUL- TURE EFFORTS ON SANTA CATALINA ISLAND, CALIFORNIA C.T. Oakes and D.J. Pondella, Hl. Vantuna Research Group, Occidental College, Department of Biology, Los Angeles, CA 90041 The Department of Fish and Game has developed the Ocean Resource Enhancement Hatchery Program (OREHP) where mariculture of white seabass, Atractoscion nobilis, is occurring along the southern California coast. The effects of white seabass shallow water net-pens used in California mariculture are not described in detail. Preliminary analysis has shown that the presence of the artificial canopy created by a floating net-pen used for mariculture in Catalina Harbor, which is next to a kelp bed (Macrocystis pyrifera), attracts fishes to it and creates a similar three dimensional community. These net-pens appear to increase localized production due to feed floating into the ambient environ- ment. We have conducted replicate band transects documenting fish size (total length) and abundance. Variation in water column productivity of fishes has been analyzed by comparing fish densities and size-classes that can be used to estimate biomass of the fish assemblage below the net-pen to those metrics occurring at reference sites. This comparison represents a novel case study for the artificial reef attraction-production controversy, as well as describing ecological change in nearby systems caused by mariculture production of fin fish in southern California. 36 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES 55 A COMPARISON OF PREVALENCE AND MEAN INTENSITY OF THE ECTOPARASITE ELTHUSA CALIFORNICA IN SHINER SURFPERCH (CYMATOGASTER AGGREGA- TA) OF TOMALES AND BODEGA BAYS Pritchard, Justin, Will Madrid, and Nick Weston-Swan. UCLA, Department of Ecology and Evolutionary Biology, Los Angeles, CA 90024 The cymothoid ectoparasite E/thusa californica is known to parasitize the opercular cavities of the Shiner Surfperch (Cymatogaster aggregata). This study examines the numbers and distributions of E. californica found on 92 C. aggregata from Nick’s Cove, Tomales Bay, CA for geographic and tem- poral comparisons with previous studies. Specimens were collected via a 6 meter impounding seine, packaged individually and then immediately examined for the presence of E. californica. No significant differences were found between the populations of Elthusa calfornica in Tomales and Bodega Bay. Isopod and host size were significantly correlated. We suggest that the populations found in both bays could be part of the same overall population. 56 ANALYSIS OF HISTORICAL CHLORDANE LEVELS IN SAN DIEGO AND MISSION BAY IN COMPARISON TO THE THRESHOLD LEVEL OF TOXICITY TO THE AMPHIPOD, EOHAUSTORIUS ESTUARIUS Y. Rodriguez'’, J. Rudolph’, C. Stransky’. 'San Diego State University; "Nautilus Environmen- tal, San Diego, CA Chlordane was produced as an organochlorine pesticide from 1945 until 1997 when it was removed from the market. Its primary use was as a general insecticide on home lawns and gardens; it was also commonly used as a termiticide. Chlordane has been frequently found in sediments at levels well above published effects-range guidelines near storm drain and creek inputs in both Mission and San Diego Bay. A Toxicity Identification Evaluation (TIE) is underway to evaluate whether chlordane levels near the Tecolote Creek entrance in Mission Bay are at levels that may explain observed toxicity to the marine amphipod Eohaustorius estuarius. Chlordane reference toxicant testing will be performed to determine a threshold level for this amphipod species. The data will then be compared to historical chlordane data accumulated over several years from both Mission and San Diego Bay. 57 SEASONAL BACTERIAL CONCENTRATIONS IN THE LONG BEACH/LOS ANGELES HARBOR COMPLEX; YEAR TWO OF A FIVE YEAR STUDY K.A Snow, K.E. Flaherty, Y.J. Ralph, C.V. Wolfe, K. Kull and R.E. Pieper. Southern California Marine Institute, Terminal Island, CA 90731 Pathogenic organisms coming from non-point sources into coastal recreational waters have been a long-standing public health concern. Freshwater outlets, such as storm drains, are a particularly high source of contamination, especially in the wet season. Bacterial species such as coliforms and enterocci are used to indicate the likelihood of pathogenic organisms in surface waters. Because elevated levels of these bacteria have been linked as a causal agent of stomach flu and other infections, California Assembly Bill (AB411) established maximum allowable concentrations of these bacteria in recrea- tional waters in 1999. The amount of total coliforms, fecal coliforms (as estimated by E. coli), and enterococcus were tested mainly in the Long Beach/Los Angeles Harbor complex seasonally and after the first flush (>0.5 inches rainfall). The results show: 1) instead of “‘seasonal’’? variation there is a more prominent wet vs. dry pattern, 2) health limits were exceeded after significant rainfall events, and 3) most concentrations abated by the time outlet plumes dissipated throughout the Harbor. Bacterial concentrations correlated negatively with salinity and positively with turbidity, supporting previous studies. The data represent two years of sampling within a 5-year monitoring project, providing data on the dynamics of bacterial concentrations in coastal recreational waters. 58 INDEPENDENT AND JOINT TOXICITY OF PERCHLORATE AND HEXAVALENT CHROMIUM TO LARVAL MOSQUITOES M.A. Sorensen and J.T. Trumble. University of California, Riverside, Riverside, CA 92521 Perchlorate and hexavalent chromium are two anthropogenic pollutants found in ground and surface water in areas throughout Southern California, as well as elsewhere in the United States and in the ABSTRACTS OF, world. In chronic exposure bioassays in the laboratory, perchlorate and hexavalent chromium were found to decrease survival and prolong development of larval Culex quinquefasciatus mosquitoes. The compounds were examined alone and in combination with each other. Perchlorate was found to have an LCSO of approximately 100,000 ug/L, while hexavalent chromium was found to have an LCS0 of approximately 900 ug/L. These concentrations are within the range of levels reported from contaminated sites. 59 VARIATION OF JOSHUA TREE MORPHOLOGY AMONG POPULATIONS IN THE EASTERN MOJAVE DESERT Tracy Valentovich and Darren Sandquist. California State University, Fullerton. Fullerton, CA 92831 The current distribution of Yucca brevifolia Engelm. (Joshua Tree) is restricted to specific habitats at higher elevations in the Mojave Desert. This distribution warrants investigation because it may represent the result of post-glacial migration and potentially restricted gene flow. The overall objective of our study is to reconstruct the phylogeography of Y. brevifolia based on morphological and genetic variances of populations in the Mojave Desert. Some taxonomic treatments of this species define more than one variety based on morphology. This includes Y. brevifolia var. jaegeriana (McKelvey, 1932), a variety of the Eastern Mojave defined by short, stout stems and short leaf lengths. In a preliminary study we examined the morphology of four populations in this region. The morphological variance of these populations was expected to be minimal, because they occurred relatively close to one another and within the described jaegeriana distribution. Trunk sizes and leaf lengths were compared among populations using ANOVA, and a broader evaluation was based on multivariate analyses of 13 tree and leaf traits. Tree sizes and leaf characteristics of three populations always conformed to the clas- sification of var. jaegeriana; the fourth population (Garnet Mountain, AZ) showed characteristics of var. jaegeriana for leaf traits but not for trunk size. Principle components analysis revealed significant scatter among plants of all populations, but clearly separated the Garnet Mountain population from the rest. These results bring into question the varietal classifications of this species and suggest that environmental factors may cause closely related populations to show notable morphological difference. 60 ENDOCRINE DISRUPTION IN SOUTHERN COASTAL CALIFORNIA FLATFISH D.E. Vidal', J. Armstrong’, M. Baker’, J. Gully*, M. Irwin®, K.M. Kelley®, D. Montagne’, J. Reyes®, D. Schlenk®, S.M. Bay'. 'Southern California Coastal Water Research Project, West- minster, CA; ?Orange County Sanitation District, Fountain Valley, CA; *University of California at San Diego, La Jolla, CA; *Los Angeles County Sanitation District, Whittier, CA; °University of California at Riverside, Riverside, CA; °California State University at Long Beach, Long Beach, CA Some anthropogenic contaminants in the environment interfere with biological processes controlled by hormones, such as sex determination or growth. Previous studies indicate some endocrine disruption (ED) effects occurring in southern California marine fish living near municipal wastewater outfalls in Orange County, the Palos Verdes shelf, and Santa Monica Bay. To determine the extent of these ED effects in the Southern California Bight (SBC), three different flatfish species collected from different locales within the SCB are being studied through our collaborative efforts. This is a multi-year project that aims to develop rapid screening and quantitative assay methods for measuring the incidence of ED effects in marine flatfish. A microarray is being developed to screen the altered regulation of genes associated with endocrine activity. Additional assay methods are being used to validate the microarray results, including a vitellogenin ELISA, gonad histology and several immunoassays for endocrine factors. Our progress is discussed in terms of how this information is leading to a better understanding of the occurrence and magnitude of ED in SCB fish from reference locations and areas proximal to municipal wastewater discharges. 61 HPLC COLUMNS WITH MODIFIED MONOSACCHARIDE DERIVATIVES AS CHIRAL SELECTOR L. Wenjian' and L. Tingyu’. 'University of California, Riverside, CA; *Mississippi State Uni- versity, Mississippi State, MS To meet the increasing demand for analyzing chiral pollutants, HPLC chiral stationary phases based on monosaccharide were prepared and evaluated. Monosaccharide D-galactose, D-glucose, D-man- nose, D-galacturonic acid and D-glucuronic acid derivatives were coupled with aminopropyl! or mer- captopropyl functionalized silica gel, and then modified by different groups on hydroxyl groups as 38 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES chiral stationary phases. The columns were screened using an identical set of racemic compounds containing a variety of functionalities and the mixture of hexane and isopropanol as the mobile phase. Chiral separation was achieved for some compounds, but baseline separation was obtained only for binaphthol and 5,5’,6,6',7,7',8,8'-octahydro-1,1'-bi-2-naphthol. Hydrogen bonding interactions were supposed to result in their chiral separation. It was observed that the chiral resolution ability of monosaccaride derivative CSPs was weaker than that of polysaccharide CSPs. These results suggest that higher level structures of polysaccharide CSPs play an essential role in chiral separation. However, the well-defined monosaccharide HPLC stationary phases could provide valuable insight into chiral recognition mechanism for saccharide-based CSPs, which will be useful for finding and developing more effective CSPs. 62 BIOAVAILABILITY OF SYNTHETIC PYRETHROIDS IN SURFACE WATER W. Yang, W. Hunter, and J. Gan. University of California, Riverside, Riverside, CA 92521 Synthetic pyrethroids are widely used pesticides in both agricultural and urban environments. Most pyrethroids have high acute toxicity to fish and aquatic invertebrates. On the other hand, pyrethroids are known for their exceptional affinity to solids. In this study, we evaluated the effects of suspended solids in surface water on the bioaccumulation of two pyrethroid insecticides, bifenthrin and permeth- rin, to aquatic invertebrates. During the bioassays, we simultaneously exposed polydimethylsiloxane (PDMS) fibers as a “‘biomimetic’” surrogate to measure the freely dissolved concentration of SPs in the test system. The concurrent analyses allowed understanding of the relationship between pesticide phase distribution and the measured bioconcentration factors (BCF) in water samples with different levels and sources of suspended solids. In all assays, the BCF consistently decreased with increasing suspended solids, suggesting that association with suspended solids reduced the bioavailability of pyrethroids. For instance, in samples containing 200 mg L™! suspended solids from Miles Creek, uptake of bifenthrin by Daphnia magna decreased 65%. Simultaneous PDMS analysis revealed that the dissolved concentration of bifenthrin decreased by 52%. The effect of suspended solids on the bioavailability of pyrethroids was controlled by both the quantity and property of suspended solids. These results suggest that suspended solids in runoff effluents and surface water can decrease the bioavailability of pyrethroids to water-column invertebrates, and this phenomenon should be consid- ered when evaluating the ecological risk and establishing water quality standards for pyrethroids. 63 STRAIN RELATEDNESS OF CANDIDA IN HUMANS: A URINARY PATHOGEN OR COLONIZER? (PHASE 1) Joon-Bok Lee. Division of Infectious Diseases, Los Angeles County Harbor-UCLA Medical Center, 1000 W. Carson Street, Torrance, California 90502 Candida species in the urine of hospitalized patients (candiduria) is a very common occurrence among hospitalized patients with over 50,000 cases complicating hospitalizations annually. However, the clinical significance of candiduria remains controversial as there is evidence that this may represent a potentially serious and deadly infection that may spread to the bloodstream, or, alternately, merely represent urinary tract colonization. To resolve this, samples of urine from over 300 patients from Harbor-UCLA Medical Center were analyzed, and data regarding the patient’s fungal infection or colonizations in different body sites, as well as their patterns of uses of antifungal medicines and urinary catheters were recorded. Differences in strains of each Candida infection (strain relatedness) were examined using traditional speciation methods as well as molecular techniques (DNA finger- printing). The results of this experiment show that Candida in the urine commonly resolves sponta- neously (97.4% or specimens) and can recur with either the same Candida strain (76.3%), or a different strain (23.7%). Furthermore, patients with Candiduria and Candidemia were more likely to lack strain relatedness (88.9%) than have strain relatedness (11.1%). Finally, antifungals did not have any effect on the persistence (3 days with versus 2.446 without treatments) nor the recurrence (2.67 recurrences with versus 2.53 without treatment) of fungal infections. Consequently, Candida in the urine among hospitalized patients does not appear to be associated with serious Candida bloodstream infections. Candiduria infectants tend to wax and wane with time, and occasionally are supplanted with other Candida strains. This suggests that most Candida strains have low pathogenicity in hospitalized pa- tients and may not require treatment. ABSTRACTS BY) 64 EFFECTS OF PHOSPHATE ON THE BIOLOGICAL PROCESSES OF TRICHODESMIUM S.F. Ong', J. Sohm?’, and D. Capone’. 'California Academy of Mathematics and Science, Carson, CA; ’Wrigley Institute of Environmental Biology, University of Southern California, Depart- ment of Biological Sciences, Los Angeles, CA The marine cyanobacterium Trichodesmium occurs throughout the tropical and subtropical oceans. These bacteria are unusual in their ability to convert atmospheric nitrogen into ammonium while undergoing photosynthesis and are responsible for the majority of the nitrogen supply in the open oceans. In exploiting their ability to fix nitrogen, the use of the oceans as a carbon dioxide sink can be maximized, helping to alleviate global warming. This research focused on the role of phosphate in the biological processes of Trichodesmium and its effect as a limiting nutrient. It is postulated that Trichodesmium has the ability to hydrolyze inorganic molecules to obtain an additional source of phosphorous, known as alkaline phosphatase activity (APA). This experiment tests Trichodesmium’s APA response in a variety of phosphate concentrations with an inorganic molecule, 4-methylumbel- liferyl phosphate (MUF-P). An inverse relationship between the phosphate concentrations and the amount of MUF-P hydrolyzed was found, confirming the theory that the cyanobacterium has the ability to provide itself with additional phosphorous, should the need arise. The experiment also analyzed the relationship between the concentration of phosphate available and the nitrogen fixing ability of 77i- chodesmium. Using the acetylene reduction process, a direct relationship between the two components was found, verifying the role of phosphate as a limiting nutrient. A better understanding of the role that phosphate plays in maintaining a elemental balance in the open oceans is essential in implementing the use of the oceans as a biological sink for carbon dioxide, thus lessening the major threat that global warming currently presents. 65 DETERMINATION OF BACTERIAL AND POLLUTANT FLOWS IN COASTAL ESTU- ARIES OF SOUTHERN CALIFORNIA S. Yanamadala and J. Dorsey. Loyola Marymount University, Department of Natural Sciences, Los Angeles, CA 90045 There are two main objectives of this experiment: to create a mathematical model showing the relationship between turbidity, dissolved oxygen, pH, salinity, time from high tide, and levels of indicator bacteria for fecal contamination and to assess the impact of the Ballona Wetlands on coastal ocean waters. In the field samples were tested for temperature, dissolved oxygen, salinity, and pH levels using the YSI 600R Sonde Electronic Probe. Further testing was done in the lab using the HACH 2100N Turbidimeter for turbidity levels and IDEXX Quantitray 2000 System with the MPN method for levels of indicator bacteria. A mathematical model was created showing the relationship between dissolved oxygen (DO), turbidity (T), pH, salinity, time from high tide, and bacterial growth (EB), where K is the constant of proportionality, and d, a, and b are constants. alc e: PH) De; Saliiicos(2it/B) ar d] Laer’) EB = K PaGolin ik — 1109" >< 102d = 85024 = 7102 b= 477 lpiecnococe: Ko — 1-90 «— 10 2d = 30:0:a =.2.49: b. = 4.77 Results indicated that bacterial levels were higher with decreased dissolved oxygen, decreased sa- linity, and increased turbidity in a neutral pH. Bacterial levels were also higher at and around high tide. This study shows that sophisticated mathematical models can be constructed to greatly simplify the current testing procedures and be more cost-effective. This model will prove critical from an economic point of view and from beach safety considerations. 66 NEAR REAL-TIME DETECTION OF ESCHERICHIA COLI FOR MONITORING BEACH WATER QUALITY J. Jay. University of California, Los Angeles, Los Angeles California Currently used methods for detecting fecal indicator bacteria in recreational water require 18—24 hours for sample analysis. Because this poses obvious problems for safeguarding public health, real- time methods for FIB and pathogen detection in environmental waters need to be developed and 40 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES tested. We are adapting for use in marine waters a recently developed method for near real-time E. coli detection based on immunomagnetic separation and quantification of ATP using luciferin/lucif- erase. We have documented levels of ATP (in RLU units) per cell in a lab culture of FE. coli during the lag, exponential, and plateau phases of the growth curve. Good calibration curves were attained at each growth phase; however, the level of ATP per cell in the E. coli population was observed to be a function of its growth phase. We are comparing the near real-time method with membrane filtration and IDEXX, a standard technique currently used extensively in Southern California for monitoring recreational water quality. 67 INDIVIDUAL AND JOINT EFFECTS OF SELENATE AND METHYLMERCURY ON A TERRESTRIAL INSECT DETRITIVORE P.D. Jensen and J.T. Trumble. University of California, Riverside, Riverside, CA Although insects play crucial roles in most ecosystems, surprisingly little is known about how anthropogenic pollutants or their mixtures affect insect populations. In this study we investigated the individual and combined effects of selenate and methylmercury on the larval stage of a ubiquitous insect detritivore Megaselia scalaris. We found that females did not avoid depositing eggs on food sources contaminated with either selenate or methylmercury. However, larval survival was significantly decreased and larval development was significantly prolonged by selenate and methylmercury indi- vidually at low or intermediate treatment levels that are ecologically relevant. In addition, potentiation was strongly evident as mixtures containing concentrations as low as only 1% of the respective individual LC;)s caused significantly more mortality and delayed larval development than would be expected from the responses selenate and methylmercury elicit individually. Indeed, the relative tox- icity to M. scalaris of each of the individual and joint treatments was selenate (LC,, = 260 pg/g) < methylmercury (LCs, = 22 wg/g) < mixture (LC,, = 13 wg/g of selenate plus 1.1 wg/g of methyl- mercury). The increased mortality and delayed larval development within sites contaminated by sel- enate, methylmercury, or the combination, have substantial implications for the ecology, population dynamics, and sustainability of M. scalaris populations. If these results can be extrapolated to other arthropod detritivores, ecosystem food-web function may be substantially affected. 68 HEAVY METALS IN THE CLAM MEGAPITARIA SQUALIDA FROM APPARENTLY POLLUTION-FREE ZONES IN BAJA CALIFORNIA, MEXICO: CONSIDERATIONS FOR HUMAN HEALTH EFFECTS L. Mendez, E. Palacios, B. Acosta, P. Monsalvo-Spencer, and S.C. Gardner. Centro de Investi- gaciones Bioldgicas del Noroeste, S.C., La Paz, Baja California Sur, Mexico Bahia de La Paz, a bay within the Gulf of California, has been traditionally characterized as free of industrial sources of pollution and having a population density low enough to avoid serious prob- lems. The “‘chocolate clam” Megapitaria squalida, 1s widely consumed by the population of several localities along the Pacific coast. Clams collected from seven stations located in Bahia de la Paz, before and after the summer rainy season were analyzed for Cd, Ni, Cu, Mn, Pb, Fe, and Zn. The location of the sampling sites significantly affected the concentration of metals in clam tissues, but not in relation to the proximity to alleged contaminated sites. Clams from a site close to a phosphate mine had the highest levels of Pb, but only in April, and the highest concentrations of cadmium were recorded in clams collected in areas without any anthropogenic activities. Clams from a sites consid- ered clean had higher levels of Cd, Fe, Zn, and Mn. The mean concentrations (ug/g dry weight) ranged from 1.5 to 11.1 for Cd, 1.9 to 8.8 for Ni, 5.4 to 18.7 for Cu, 2.5 to 9.3 for Mn@0Giosies for Pb, 154 to 558 for Fe, and 47.2 to 64.6 for Zn. Based on the results obtained in this study, the consumption a regular meal of 200 g of clam tissue does not represent a risk for human health and proportion a good source of essential elements. 69 SUSCEPTIBILITY OF OXIDATIVELY CROSSLINKED $-AMYLOID PEPTIDES TO IN- SULIN DEGRADING ENZYME J. Young. Alhambra High School and USC Keck School of Medicine, School of Pharmacy, Department of Pharmaceutical Science, Los Angeles, CA, 90089 Amyloid-Beta protein (AB) plays an important role in the pathogenesis of Alzheimer’s disease and is thought to be the cause of neuronal deaths. Oxidized AB and oxidatively crosslinked were examined to see if they were less susceptible to protease digestion by insulin-degrading enzyme (IDE), a major ABSTRACTS 4] AB degrading enzyme and compared digestion by the more general protease, trypsin. AB40 and AB42 peptides were each oxidized with either NBS or CU/H202. Oxidized AB40 and AB42 lyophilized and resuspended and then desalted using C18 spin columns. They were then assayed using BCA protein method to determine the recovery of AB from the columns. Non-oxidized and oxidized AB40 and AB42 were subjected to proteolysis with IDE or trypsin and then were electrophoresed and analyzed by Western blot. Results have shown that trypsin is able to degrade unoxidized AB40 and AB42 but is unable to digest oxidized samples of AB. IDE was only able to digest partial amounts of unoxidized and oxidized AB. This is a deviation from previous research which has shown that IDE is able to fully degrade unoxidized AB. Further research may be continued to determine whether there may be inhibitions in IDE’s abilities to degrade AB due to oxidation. 7 THE HISTORY OF WILDLAND FIRES IN AMERICA RJ. Vogl. Biology Department, California State University, Los Angeles 90032 Fire was a common tool used by pioneers, loggers, farmers, and ranchers prior to 1900. Natural ignitions burned uncontrollably. Promiscuous and careless uses of fire lead to restrictions shortly after 1900. The Smokey-the-Bear anti-fire campaign and propaganda was so effective that by 1940 burning in America was virtually shut down. Burning persisted in only a few local areas, labeled “‘backward”’ by the Government. Starting in 1960, ecological studies began to document the natural role of fire in various wildlands and to question U.S. policies of putting out all fires and labeling all fires as bad. By 1980 controlled burning was becoming commonplace and plans were being made to let some lightning ignitions burn. Most federal and state agencies dealing with natural resources had developed prescribed burning guidelines. The movement to restore the natural role of fire suffered a setback with the massive 1988 Yellowstone wildfire. Questions of liability, inability of burners to obtain insurance, and lack of confidence and skill, and concerns about costs, budgets, limited burning opportunities, and other bureaucratic red tape began to delay burning. As a result, the restoration of fire to appropriate ecosystems in their natural sequence continues to be inadequate. This is particularly true in southern California where chaparral occurs on steep terrain and is juxtaposed on urban development. Mean- while, the payback of a century of fire exclusion continues with one record-breaking wildfire after another, year after year! 72 ECONOMIC IMPACT OF WILDLAND FIRES Armando Gonzalez-Caban. USDA Forest Service, Pacific Southwest Research Station, Forest Fire Laboratory, 4955 Canyon Crest Drive, Riverside, California 92507, Phone: 951.680.1525; Fax: 951.680.1501, Email: agonzalezcaban @ fs.fed.us A recent international symposium on fire economics held in Cordoba, Spain highlighted many of the common concerns with the problems of wildland fires throughout the world. Some of the most prominent reasons presented for the continuous and increasing wildland fire problem were related to social and economic factors such as poverty in rural areas, particularly in developing countries econ- omies, and land abandonment of the rural areas in Europe. A related problem, and possibly the most prominent here in California, is the population increase and higher concentrations along forested areas, creating the new coined problem of the wildland urban interface (WUI). It was evident from regional presentations at the symposium that the costs associated with the wildland fires problem and fire management programs are substantial ranging in the billion of dollars. For example, since 2000, the United States Department of Agriculture Forest Service (USDAFS) alone has spent more than $1 billion annually in forest fires suppression. Canada spends and average of $400 to $800 million annually. Neither of these figures includes timber, health, recreation or personal property related expenditures. In the South American continent losses are estimated as high as $1.6 billion annually. Recent estimates of the impacts of the Indonesian fires of 1997 on the economies of Indonesia, Malaysia, and Singapore were as high as $4.5 billion. Closer to home, in 2003, in California alone, 750,043 acres were burned, 3,710 homes destroyed, 24 lives lost, and more than $3.5 billion in property losses! 42 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES 73 POST-FIRE EROSION IN THE SAN GABRIEL MOUNTAINS P.M. Wohlgemuth. USDA Forest Service, Pacific Southwest Research Station, 4955 Canyon Crest Drive, Riverside, CA 92507 Wildfire is a significant disturbance event that promotes accelerated erosion in upland watersheds. This accelerated erosion can cause environmental site degradation and may threaten life, property, and infrastructure in human communities downstream at the wildland/urban interface. Management treat- ments following a wildfire in 1960 involved the vegetation type-conversion of some native chaparral watersheds to a mixture of perennial grasses on the San Dimas Experimental Forest (SDEF) in the San Gabriel Mountains. In September 2002 virtually the entire SDEF burned again in the Williams Fire, including several small (2—3 ha) headwater catchments in both brush and grass fuel types. Hillslope erosion was measured in 30 cm aperture sediment collector traps. Pre-fire erosion was 10 times greater under native chaparral than on grass hillsides. Compared to pre-fire erosion, first year post-fire hillslope erosion was ten times greater under brush vegetation and over 100 times greater under grass. Prescribed fire produced less erosion than wildfire on comparable chaparral hillsides. Small watershed sediment yield was measured in reservoirs behind debris dams. Prior to burning, sediment yield in both grass and chaparral watersheds was small, and varied with annual rainfall. After the wildfire, large amounts of sediment were delivered to the reservoirs under moderate rainfall, regardless of vegetation type. Prescribed fire produced less sediment yield than wildfire in comparable chaparral watersheds. Although accelerated erosion and sediment yield after burning appears to be inevitable, prescribed fire may be an effective sediment management tool. 74 NEW TRICKS ON THE OLD FIRE Fujioka, Francis M. USDA Forest Service, Forest Fire Laboratory, 4955 Canyon Crest Drive, Riverside, CA 92507 The Old Fire will not soon be forgotten by Southern California firefighting agencies. In October 2003, it burned over 90,000 acres, 940 homes, and 30 commercial structures. It resulted in six fatalities, and contributed to a deadly flash flood in Waterman Canyon two months after the fire. The Old Fire also was the first time that an integrated weather/fire behavior modeling system was used to predict the fire’s growth on a daily basis. This presentation describes the weather modeling (MM5), fire behavior modeling (FARSITE), and fire imaging (FireMapper™) technologies that provide a powerful array of tools for wildland fire science and management. 75 STRATEGIC FIRE MAPPING—-TECHNOLOGY DEVELOPMENT FOR AIRBORNE RE- MOTE SENSING OF WILDLAND FIRES Philip J. Riggan. USDA Forest Service, PSW Research Station, 4955 Canyon Crest Drive Riverside, CA 92507 A new airborne thermal-imaging radiometer, the FireMapper®, has been developed by the Pacific Southwest Research Station (PSW) and Space Instruments, Inc, for strategic fire mapping and to improve fire suppression operations, fire-fighter safety, and our understanding of the behavior and environmental impacts of wildland fire. Based on night-vision technology developed by the U.S. Department of Defense, FireMapper measures thermal radiation from spot fires and intense flaming fronts alike; resulting estimates of ground-surface temperatures provide a measure of the intensity and progress of wildland fires. The FireMapper was deployed during the fire emergency in California during 2003 aboard PSW’s Airborne Sciences Aircraft, N70Z, a twin-engine Piper Navajo. Data were uplinked by satellite communication, geo-referenced to a map base, and posted to the Internet at www.fireimaging.com for use by fire operations. Best delivery time to the Internet was 90 minutes. The PSW system has now been improved with an advanced inertial navigation system and satellite communications with a goal of delivering data to the Internet in less than one-half hour. Next-gen- eration FireMapper 2.0 instruments have also been engineered and put into use aboard N70Z and N30W, an Aerial Supervision Module operated by the Bureau of Land Management. ABSTRACTS 43 76 CHANGES IN SPATIAL DISTRIBUTION AND ABUNDANCE OF BIRDS IN RELATION TO FIRE AND DROUGHT-INDUCED VEGETATION MORTALITY IN SOUTHERN CAL- IFORNIA Rechel, Jennifer L. USDA Forest Service, Pacific Southwest Research Station, Forest Fire Lab- oratory, Riverside, CA, USA 92507-6071 Avian community changes were studied in relation to fire history and a severe drought in a Med- iterranean ecosystem in the San Jacinto Mountains in southern California for five years pre-drought (1997-2001) and a planned five years post-drought (2004—2008). Plots were established in mixed oak, mixed conifer, and mixed chaparral vegetation types. Bird surveys were conducted on 87 variable circular plots during migration and breeding periods (March—June) using trained observers for five minutes between 0600 and 1030. Vegetation was measured at two sites on each bird plot. Habitat data included tree age (based on cores and fire history), height, dbh, canopy cover, shrub cover, and herbaceous cover. We used a geographic information system (GIS) and logistic regression to predict and map the pre-drought spatial distribution of birds. Resident granivorous and insectivorous birds were most likely associated with old growth (> 50 years since last burn) chaparral stands. Migratory insectivorous birds were associated with mixed oak woodlands adjacent to water and patches of mixed conifers. First year results of the post-drought data indicate increases in relative densities of resident birds in plots with high drought-induced tree mortality and no changes in relative densities of migratory birds in those plots. These preliminary analyses suggest that fire and drought related vegetation mor- tality are not necessarily detrimental to avian communities and have mixed effects on these commu- nities. T7. THE CONTRIBUTION OF FOREST INSECTS AND PATHOGENS TO TREE MORTALITY IN SOUTHERN CALIFORNIA MONTANE FORESTS L.D. Merrill. USDA Forest Service, 4955 Canyon Crest Drive, Riverside, CA 92507 A severe multi-year drought in southern California caused extensive vegetation mortality which peaked in 2003. That September aerial surveyors mapped woody vegetation mortality above 1% (background) on 522,000 acres of a total of 819,000 acres on the San Bernardino National Forest. Woody vegetation mortality of above 10% was observed on 450,000 acres. In some areas pine mor- tality approached 100%. The Peninsular Ranges of San Diego Co. experienced similar levels of mor- tality, while less mortality occurred in the Transverse Ranges west of the Cajon Pass. Pine forests were especially affected because of an outbreak of native bark beetles, in particular, Dendroctonus brevicomis, D. ponderosae, and D. jeffreyi. These bark beetles kill pines that might otherwise survive drought. Air pollution injury and plant diseases, especially Heterobasidion annosum and Arceuthobium spp., contributed to tree stress, facilitating successful colonization by bark beetles. Less aggressive insect pests, particularly /ps spp., Scolytus ventralis, and Melanophila californica, killed trees not colonized by more aggressive insects. In 2004 pine mortality and the population of D. brevicomis declined for unknown reasons. Bark beetle populations are expected to drop further because of above average precipitation this winter. Public and private landowners responded to the mortality by remov- ing dead trees to reduce hazardous fuels around communities. Long term effects of the mortality are unknown, but include lengthy recovery times for some ecosystems (e.g., single leaf pinyon in the Santa Rosa Mountains), probable increase in H. annosum infection centers, and possible species and genetic shifts associated with forest regeneration and replanting. 78 WILDFIRE AFFECTS SOUTHERN CALIFORNIA RIPARIAN HABITAT M. G. Narog, C. J. Sclafani, and J. L. Beyers. USDA Forest Service, Pacific Southwest Research Station, Riverside, CA In June 2002, two wildfires (Louisiana and Blue Cut) burned over 13,000 acres, including important riparian habitat along Cajon Creek near Cajon Pass, San Bernardino County, CA. Cajon Pass is a heavily used corridor with freeways, trains, and utilities that run alongside and bridge Cajon Creek. This and adjoining perennial drainages are used for recreating and are channeled for flood control. Natural processes are thus disrupted, and the distribution and range of many species is constrained. Sections of Cajon Creek were denoted suitable habitat for three federally listed species—arroyo toad (Bufo californicus), least Bell’s vireo (Vireo bellii pusillus), southwestern willow flycatcher (Empi- 44 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES donax traillii extimus); and one forest sensitive species—Santa Ana speckled dace (Rhinichthys os- culus). After the fires, all burned trees near the railroad bridges that crossed Cajon Creek were cut. We initiated a study to determine how fire and tree removal affected the riparian habitat for the native species. We sub-sampled vegetation with line transects running across the creek in unburned, burned, and burned and cut areas. Tree removal reduced recovery rate of burned area vegetation for both height and percent cover. Burned area shrubs and herbaceous plants benefited from the reduced over- story. Rapid recovery of suitable habitat for fauna was observed, but vertical dimensions were still below pre-burn measures 2 years later. Post-fire bird surveys revealed continued use of the riparian area, and Santa Ana speckled dace were observed in Cajon Creek. Many species using this riparian area demonstrate remarkable resilience to fire and post-fire disturbances. hs) SAN DIEGO FIRE RECOVERY NETWORK: WORKING AND LEARNING TOGETHER M. McElhinney, San Diego Fire Recovery Network; and A.S. Fege, San Diego Natural History Museum, Box 121390, San Diego, CA 92112 The October 2003 wildfires were unprecedented for San Diego—with 16 deaths, 2600 homes lost, and 390,000 acres blackened. We were awed by the power of wildfire, by the personal and community losses, by nature’s resilience and recovery, and by the reality that we are “‘between fires”’ in these Mediterranean and semi-arid ecosystems. Less than a week after the October 2003 wildfires began, the San Diego Fire Recovery Network was formed, holding meetings at the San Diego Natural History Museum. This open network has representation from more than 100 scientific and community orga- nizations, and public agencies working together to foster the recovery of our human and _ natural environment through sound science, public education, land and community restoration. More than 400 professionals have attended one or more of the workshops and meetings on fire ecology of chaparral; fire ecology of San Diego’s forests; “‘firesafe’’ construction and “‘firewise” landscaping; and post-fire watershed recovery. Professionals, volunteers and students worked together on wildlife surveys through the San Diego Mammal Atlas and Bird Atlas, wildfire education videos, the Earth, Wind & WILDFIRE exhibition at the San Diego Natural History, community fire plans, and more. In cooper- ation with the US Forest Service Riverside Fire Lab, four interdisciplinary workshops will be held in June 2005 across southern California to help define the socioeconomic and political gaps in reducing wildfire risks in chaparral ecosystems while sustaining native habitats, biodiversity, and watersheds as wildland-urban interface and exurban development accelerate. 80 HOW ISLAND SCRUB-JAYS ATTAIN BREEDING STATUS IN LIMITED HABITAT K. A. Corey, C.T. Collins. U.S. Fish and Wildlife Service, Carlsbad Field Office, Carlsbad, CA 92009; Department of Biological Sciences, California State University, Long Beach, CA 90840 The Island Scrub-Jay, Aphelocoma insularis, is an endemic resident of Santa Cruz Island. Earlier studies have shown these birds to be permanently territorial and monogamous. Young birds generally take three or four years to obtain a territory. The most common method is for a pre-breeder to replace a member of an established pair upon the death of an adult of either sex. Other documented methods include usurping a territory upon the death of one breeder, amalgamation of adjacent territories and divorce and re-pairing of older breeders. Whatever the method utilized, obtaining a territory or be- coming part of a territorial pair is prerequisite to becoming part of the breeding population 81 POPULATION GENETICS OF PYGMY NUTHATCHES IN SOUTHERN CALIFORNIA T. A. Benson and A. E. Metcalf. Department of Biology, California State University, 5500 University Parkway, San Bernardino, CA 92407 We sequenced 1639 base pairs of mitochondrial DNA to examine the distribution of genetic vari- ation among pygmy nuthatch (Sitta pygmaea) populations in southern California. Pygmy nuthatches are small songbirds resident in coniferous forest throughout western North America; they occur in the mountains of southern California as disjunct sky island populations. In order to determine the extent of gene flow among these disjunct populations, we used portions of cytochrome b, ND6, and the control region to characterize the genetic differentiation within and among mountain ranges, as well as between the 2 subspecies (S. p. melanotis and S. p. leuconucha) that occur within the study area. Analysis of 75 individuals from 11 collecting locations in 7 mountain ranges yielded 17 haplotypes. ABSTRACTS 45 Measures of genetic distance were low among both haplotypes and populations (mountain ranges). Phylogenetic analyses showed strong support for several haplotype clades. These clades, however, appear only weakly correlated with geography. The overall F,,; for mountain range comparisons was relatively low but significant, indicating the presence of some genetic structure. Additionally, a Mantel test based on collecting locations revealed a significant isolation by distance effect. Results from AMOVA suggest weak but significant genetic differentiation between S. p. melanotis and S. p. leu- conucha, with the restriction of gene flow occurring between the Transverse and Peninsular Ranges. Overall, these results indicate that gene flow is restricted among southern California pygmy nuthatch populations, but that these populations are recently diverged. 82 SEASONAL AND INTERANNUAL MOVEMENTS OF SALTON SEA- HATCHED BLACK SKIMMERS (RYNCHOPS NIGER) K. C. Molina and K. L. Garrett. Natural History Museum of Los Angeles County, Los Angeles, CA 90007; C. T. Collins. California State University, Long Beach, CA 90840 Over 2570 pre-fledging Black Skimmers (Rynchops niger) have been banded at the Salton Sea in southeastern California between 1991 to 2004; nearly all of these were given additional alphanumeric or color bands to identify individuals or cohorts. Our re-sighting efforts in coastal California and western Mexico during the non-breeding season have yielded important information on migratory movements and suggest considerable interconnectivity of breeding populations throughout the region. Of the 937 skimmers banded at the Sea in the years 1999 to 2001, 275 birds have been re-sighted at least once. Of 62 of these birds re-sighted during the first winter after fledging, 37 (60%) were along the Pacific Coast of California or northwestern Baja California and 25 (40%) were in the Gulf of California or the mainland west coast of Mexico. Analysis of the remaining re-sighting data shows a complex set of outcomes, with some birds that disperse to the Pacific Coast remaining there to breed, but others returning to breed at colonies at the Salton Sea or Colorado River delta region. Most birds dispersing to the Gulf and western Mexico remain to breed in the Salton Sea/Gulf region (south at least to southern Sonora), but some have appeared at coastal California colonies. Furthermore, some birds banded as pre-fledglings in coastal California colonies have wintered on the west coast of mainland Mexico and in a few cases have subsequently been re-sighted at Salton Sea breeding colo- nies. 83 OVER-WINTERING BEHAVIOR OF BLACK SKIMMERS IN SOUTHERN CALIFORNIA: SITTERS AND WANDERERS C. T. Collins, K. Molina and K. L. Garrett. Department of Biological Sciences, California State University, Long Beach, CA 90840; and Natural History Museum of Los Angeles County, 900 Exposition Blvd., Los Angeles, CA 90007 The Black Skimmer is a recent, but now well established, breeding species in southern California. A large portion of the coastal population, augmented by birds from the Salton Sea colonies, now over- winters at 3—4 local sites. Although these sites are regularly used by skimmers year after year, site fidelity of individual birds is highly variable. Some individuals have been regularly, if not always, found at only one site winter after winter. Others move between sites, even One or more times within a single winter season. The causes for these contrasting behaviors are not readily apparent although adverse weather conditions may play a role in some cases. 84 AVIAN EXTIRPATION AND COLONIZATION IN THE BALLONA VALLEY, LOS AN- GELES COUNTY, CALIFORNIA Daniel S. Cooper. Audubon California, 11340 W. Olympic Blvd., Suite 209, Los Angeles, CA 90064 Successful ecological restoration depends on a clear understanding of the history of local species loss and colonization. One area of California where this can be uniquely achieved is the Ballona Wetlands, one of the best-studied coastal habitats in the state, recently acquired for restoration and protection as a proposed Ecological Reserve. Though birds are among the primary beneficiaries of this effort, the avifauna of Ballona has not been critically examined in more than 60 years. Drawing from historical and current records, I identify 40 taxa that have been extirpated from the wetlands in 46 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES one or more role since 1900. Of these, 11 have subsequently become reestablished as regular nesters or winterers after an absence of several decades, and 19, including four non-native taxa, have appar- ently colonized in one or more roles since the mid-1900s. I analyze this turnover in terms of three major periods of local habitat change, including stream-channelization; wetland draining and creation; agricultural expansion and decline; urban expansion; the construction of a massive marina; and the spread of non-native plant and animal species. This research should facilitate the development of target species to be monitored as the system is restored 85 CHANGES IN BIRD SPECIES DIVERSITY FOLLOWING A SALTMARSH RESTORATION PROJECT AT BATIQUITOS LAGOON K.M. Keane. Keane Biological Consulting, 2892 N. Bellflower Blvd., Suite 480, Long Beach, CA 90815 Batiquitos Lagoon is located in the City of Carlsbad, north San Diego County. Once a tidal system, it was largely non-tidal for 90 years, prior to a $60 million lagoon restoration project conducted from 1994 through 1996 as a mitigation project by the Port of Los Angeles. Following restoration, a long- term biological monitoring program was initiated. It included surveys for vegetation, fish, benthic infauna and birds in years 1, 2, 3, 5, and 10 following lagoon restoration. Avian surveys were per- formed quarterly during those years to document the changes in bird usage following construction. During 1998 and 1999, mudflat habitat supported the highest densities of birds during all quarters. This was a change from 1997, when shallow water and open water supported substantially higher densities of birds, and was due to development of mudflats within the lagoon following construction. Other changes in bird habitats, species diversity, overall bird numbers, bird guilds, and populations of special-status species at the lagoon observed during surveys conducted in 1997, 1998, 1999 and 2001 will be discussed. 86 SPECIAL STATUS BIRDS OF THE WHITTIER NARROWS BASIN, LOS ANGELES COUNTY M.C. Long. Los Angeles County Natural Areas, 1750 N. Altadena Dr., Pasadena, CA 91107 The 1500 acre Whittier Narrows Recreation Area and adjacent San Gabriel River and Rio Hondo Rivers in South El Monte supports a remarkable diversity of bird species. A total of 293 bird species (298 species and subspecies) has been recorded in the area through April 2005. Particularly important to birds is the presence of year-round surface water in the form of ponds, lakes and streams and the associated riparian vegetation. Analysis of over forty years of records resulted in the publication of the first comprehensive, annotated work on bird species occurrence and seasonal use of the area (currently under revision). The area supports over fifty Special Status bird species (some seventy species from the State Special Animals List have occurred) such as Least Bittern and Least Bell’s Vireo, and these are highlighted as to seasonal distribution and breeding status. Recent changes in the status of several species, such as establishment of heron and cormorant rookeries and nesting yellow warblers, and current land use conflicts and management difficulties are briefly discussed. 87 POPULATION STATUS OF ROYAL TERNS IN SOUTHERN CALIFORNIA C. T. Collins. Department of Biological Sciences, California State University, Long Beach, CA 90840 The Royal Tern, Sterna maxima, is an abundant seasonal breeder on the Atlantic and Gulf coasts. On the Pacific coast, however, it is decidedly less common, with perhaps fewer than 100 pairs currently breeding in California. This is very different from the situation 50 years ago when it was one of the commonest large terns in this area. Its decline and recovery (?) seems related to a similar decline (and recovery?) of a favorite inshore prey item, the Pacific Sardine, Sarninops sayax. Adult annual survival is high (>88%), as is true of other tern species, and the local breeding population seems to be increasing, albeit slowly. | , | | | ABSTRACTS AT 88 POPULATION STATUS OF THE CALIFORNIA LEAST TERN K.M. Keane. Keane Biological Consulting, 2892 N. Bellflower Blvd., Suite 480, Long Beach, CA 90815 The California least tern (Sterna antillarum browni) breeds from April through August at nesting areas along the coast from the San Francisco Bay, California to lower Baja California, Mexico. Prior to its listing as endangered under both the federal and California Endangered Species Act in the early 1970’s, the progressive conversion of suitable nesting habitat to human uses had resulted in a severe reduction in both nesting sites and numbers of nesting pairs. Thereafter, the number of nesting pairs in California escalated from an estimated 664 in 1976 to over 6,000 in 2004, and up to 38 nesting sites are now used, up from 23 in 1976, when statewide censuses were initiated. However, over 80% of the nesting population is concentrated in 10 sites. In addition, poor production years such as 1999 still threaten the population, as does predation by a variety of both native and non-native predators. Thus, continued management will be required to ensure long-term survival. Population and produc- tivity fluctuations, existing management and monitoring methods and recommendations for future monitoring and management will be discussed. 89 LEAST BELL’S VIREO IN THE SANTA ANA RIVER WATERSHED R. Zembal. Orange County Water District, 10500 Ellis Avenue, Fountain Valley, CA 92708 At one time considered common, the least Bell’s vireo Vireo bellii pusillus was widely distributed throughout the Central Valley and other low elevation riverine systems of southern California and Baja California, Mexico. However, by the mid-1900s habitat loss due to agricultural, urban, and commercial developments, flood control and river channelization projects, livestock grazing, and other activities had severely reduced the available habitat and the vireo was extirpated from much of its former range. Nest parasitism by brown-headed cowbirds Molothrus ater greatly limited the vireos’ reproductive output and in concert with habitat loss, vireo numbers plummeted. When the vireo was finally listed as endangered in 1980, there were only 300 pairs known to exist throughout the historic range. Orange County Water Districts’ vireo management program began in 1986 when:21 territories and 19 pairs were documented. Nineteen nesting seasons later in 2004 there were 590 vireo territories found in the Prado Basin. The efforts in the basin have been mirrored outside the basin throughout the watershed since 2000 by the District and its partners in the Santa Ana Watershed Association (SAWA) and an additional 249 vireo territories were observed on the river and tributaries in 2004. Thus, the Santa Ana River held a minimum total of 837 territories in 2004 compared to 824 territories on Camp Pendleton. The expansion of the vireo population on the Santa Ana River was achieved by dedicated field staff adaptively managing natural resources. The significance of this achievement is that it happened on a river system that has been greatly altered by human activity and has been dramatically narrowed and heavily urbanized to its very edges. It demonstrates that consistent wildlife management works for some species. 90 POPULATION STATUS OF THE WESTERN GULL-BILLED TERN (STERNA NILOTICA VANROSSEMD IN NORTH AMERICA K. C. Molina. Ornithology, Natural History Museum of Los Angeles County, 900 Exposition Blvd., Los Angeles, CA 90007 The Western Gull-billed Tern is a highly localized breeder, nesting at just a handful of locations in California and western Mexico. In California, the tern forms small nesting colonies at only two locations, the Salton Sea and south San Diego Bay. Gull-billed Terns colonized the Salton Sea by the late 1920s, but the colony in San Diego Bay was not established until 1986. Until recently, a lack of information on breeding locations in western Mexico has hampered efforts to estimate the total pop- ulation size for this subspecies; the only known colonies were in the Colorado River delta region (Cerro Prieto and Isla Montague) and Bahia Santa Maria, Sinaloa. Surveys in Mexico in 2003 by Palacios and Mellink documented the existence of four previously unknown breeding locations, one in Baja California Sur, two in Nayarit and one in Colima, bringing the number of colony sites in Mexico to seven. Colony sizes are generally small but ranged from 2 to 200 pairs. Results of simul- 48 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES taneous surveys in California and western Mexico in 2003 suggest that the entire breeding population of the Western Gull-billed Tern consists of fewer than 600 pairs. The expected degradation of habitats at the Salton Sea as a result of reduced freshwater inflows and proposed urban development, and conflicts with listed species in San Diego threaten the viability of this species in California. 91 POPULATION STATUS OF LIGHT-FOOTED CLAPPER RAIL R. Zembal, S.M. Hoffman, and J. Konecny. Department of Biological Sciences, CA State University, Long Beach 90840 The Light-footed Clapper Rail (Rallus longirostris levipes) is a State and Federally listed endangered species that is resident in coastal wetlands in southern California and northern Baja, California, Mex- ico. Loss and degradation of habitat threaten the continued existence of this bird, although management efforts now offer some promise of recovery. The twenty-fifth annual census of the Light-footed Clapper Rail in California was conducted from 23 February—23 May 2004. Thirty coastal wetlands were surveyed by assessing call counts from Carpinteria Marsh in Santa Barbara County, south to Tijuana Marsh National Wildlife Refuge (NWR) on the Mexican border. A total of 350 pairs of Light-footed Clapper Rails exhibited breeding behavior in 15 marshes in 2004. This is the largest statewide breeding population detected since the counts began in 1980, representing an 8% increase over the former high in 1996 and a 22% increase over the 2003 total. Upper Newport Bay and Tijuana Marsh NWR were at all-time highs, together supporting 44 pairs more than in 2003. The Newport subpopulation comprised 47.1% of the state population in 2004 and together with the subpopulation in the Tijuana Marsh NWR totaled 252 pairs, or 72% of the breeding population of this rail in California. The subpopulation at Point Mugu is now the third largest in the state with 19 pairs. Although the Seal Beach tally continued to decline, 5 of the other small subpopulation were at record or recent highs. Most notably, the Kendall-Frost Reserve supported 14 pairs and there were 11 pairs in Bati- quitos Lagoon and 6 pairs in the San Dieguito River Valley. Excluding the 4 largest subpopulations, the remaining |1 totaled 63 breeding pairs of clapper rails, 18% of the state total. The rebounding of several of the small subpopulations gives reason to believe that restoration and management can work for the Light-footed Clapper Rail. 92 THE STATUS OF WESTERN SNOWY PLOVERS IN COASTAL SOUTHERN CALIFORNIA Kevin B. Clark. U.S. Fish and Wildlife Service, Carlsbad, CA 92009 Historically, coastal Southern California supported one of the largest breeding and wintering pop- ulations of Western Snowy Plovers (Charadrius alexandrinus nivosus) along the Pacific Coast. Human population growth and easy access to beaches has resulted in most historical snowy plover breeding habitat being converted to recreational uses. Today, breeding Western Snowy Plovers are distributed among four major sites in coastal southern California: Bolsa Chica Ecological Reserve, the Santa Margarita River mouth, Batiquitos Lagoon, and the Silver Strand on the west side of San Diego Bay from Coronado to the U.S./Mexico border. Based on the results of a population viability analysis, the recovery goal for southern California is 500 breeding adults. The 2004 breeding season window survey counted 281 breeding adults in the region, which is likely an underestimate, but continues a five year trend of increasing numbers. Wintering numbers have increased slightly over the past five years, with the largest wintering flocks located at Zuma State Beach, the Santa Margarita River mouth, the Silver Strand, and the Tijuana River mouth. Winter totals have increased from 833 birds in 2003, to 847 in 2004, to 894 in 2005. The major limitations to population growth include nest predation and lack of suitable breeding habitat. Efforts to restore beach habitat are underway but are constrained by the intense recreational uses of beaches year round and beach raking that removes foraging and breeding habitat. 93 DIETARY RESPONSE OF THE ELEGANT TERN (STERNA ELEGANS) TO CHANGING OCEAN CONDITIONS AND PREY POPULATIONS IN SOUTHERN CALIFORNIA K. L. Connell and M. H. Horn. California State University, Fullerton, Department of Biological Science, Fullerton, CA 92834 We compared the diets of Elegant Terns at three nesting sites in southern California in 2004 to help determine whether ocean conditions have shifted from a warm to a cool regime since 1999 and therefore whether this abundant seabird can indicate oceanographic regime changes. Previous studies ABSTRACTS 49 have shown that the northern anchovy is a major prey species for this tern, but during warmer years the Pacific sardines can become a more important prey species. If the ocean is now in a cool regime, we expected a higher anchovy to sardine ratio in this tern’s diet at all three sites, but more pronounced at the two northerly locations (Los Angeles Harbor and Bolsa Chica Ecological Reserve). We also expected Elegant Terns to have a broader diet at the more southerly site (San Diego Salt Works) because of a subtropical influence. Diets were assessed by identifying fish dropped by the birds or regurgitated by the young during parent-chick feeding encounters at the colonies. The anchovy to sardine ratios from the Los Angeles and Bolsa Chica samples were significantly larger than the San Diego site. Prey composition, but not prey diversity, also differed significantly among sites. Based on a Pacific Decadal Oscillation (PDO) index, dietary species composition from 1993 to 2004 at Bolsa Chica differed significantly between years of cooler and warmer conditions. Our work to date shows apparent influences of climate on prey availability and Elegant Tern diet in the region, but we are continuing our analysis to resolve the picture. 94 GAS EXCHANGE RESPONSES TO PULSE RAIN EVENTS BY A NATIVE HAWATIAN DRY FOREST VINE AND THE EFFECT OF INTERACTION WITH NON-NATIVE GRASSES P.A. Koenig and D.R. Sandquist. Department of Biological Science, California State University, Fullerton, CA 92831 The dry forests of Hawaii have experienced reduced seedling recruitment since invasion by Pen- nisetum setaceum, a C,, perennial bunch grass native to Africa. Precipitation in these forests is spatially and temporally variable at the seasonal and annual scales. In a common garden experiment we ex- amined the use of pulse rain events by seedlings of Canavalia hawaiiensis a vine native to the Hawaiian dry forest. Canavalia seedlings (grown with and without the presence of Pennisetum) re- ceived simulated pulse rain events of five sizes and their gas-exchange responses were monitored. Plants responded to water pulses of as littke as 5 mm, but at least 20 mm was required for a lasting (23 day) response. However, in the presence of Pennisetum, responses were lower and shorter lived, suggesting that in the presence of the Pennisetum additional water input is required for the gas ex- change plateau to be reached. These results suggest that the reduction of native seedling recruitment can partly be explained by altered resource dynamics, specifically pulse moisture utilization, due to invasion by Pennisetum. 95 BORN AND RAISED IN SOUTHERN CALIFORNIA: DEVELOPMENTAL EVOLUTION AND CRYPTIC SPECIATION IN THE SEA SLUG GENUS ALDERIA R.A. Ellingson and P.J. Krug. California State University Los Angeles, Department of Biological Sciences, Los Angeles, CA 90032 Variable development within a single species (poecilogony) is a rare phenomenon, and putative examples often comprise cryptic species. The sacoglossan genus Alderia contains a single recognized species in north Atlantic and Pacific estuaries; it produces feeding larvae (planktotrophy) throughout its distribution except in California, where both planktotrophy and lecithotrophy (non-feeding larvae) are expressed. Molecular, morphological and developmental evidence indicate that populations south of Bodega Harbor comprise a true poecilogonous species, distinct from the strictly planktotrophic congener A. modesta. Northern populations (Bodega to Vancouver) consist of large adults with a smooth dorsum that produce planktotrophic larvae; those from Tomales Bay south consist of smaller adults with a raised dorsum that seasonally toggle between planktotrophy and lecithotrophy. Sequences of the mitochondrial cytochrome oxidase I gene were obtained from 204 individuals from 14 popu- lations. Northern and southern haplotypes formed reciprocally monophyletic clades differing by 16— 20%, including fixed differences at 36 of 480 sites. Molecular clock calibration indicates the species have diverged since the early Pleistocene (1.4 million years ago). The northern species is absent from the south of Tomales Bay yet common only 4 km away, and was rare in San Francisco Bay until recruiting in large numbers in Feb. 2005; population dynamics may reflect differential colonization of, or adult survival on, regionally distinct strains of the host algae Vaucheria spp. Southern Vaucheria strains may limit slug body size, selecting against planktotrophy in the southern species by limiting fecundity in the face of high planktonic mortality. 50 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES 96 SHALLOW SURF RIDERS: SMALL-SCALE LARVAL DISTRIBUTION IN ESTUARINE WATERS D.A. Willette and PJ. Krug. California State University, Los Angeles, Department of Biological Sciences, Los Angeles, CA 90032 Larval supply to settlement sites strongly affects the distribution of marine organisms, but it is unclear how physical properties of the water column influence larval abundance at small spatial scales. We measured the near-bottom concentration of larvae over shallow mudflats in Newport Bay and the Cabrillo Wetland, San Pedro. For 12 months, larvae were sampled 1—10 cm above the substratum over a 3 hr flood tide for 3 consecutive days per month per site. Larvae were sorted live, grouped by taxon and identified to genus or species by DNA sequencing. Day-to-day variance in larval abundance was unexpectedly high, and concentrations were often radically skewed between the 2 heights on a given day, but evenly or reverse-distributed the next day. Such changes in small-scale distribution were observed for all major taxa, although spionid and barnacle larvae were consistently more abun- dant at 5 cm. Overall abundances at Newport were 3 higher for veligers, 17 higher for spionids, and 31x higher for pediveligers than at Cabrillo, whereas barnacle nauplii were 5X more abundant at Cabrillo. Flow measurements were recorded near the bed using an Acoustic Doppler Velocimeter (ADV) during sampling, revealing complex oscillatory flows; hydrodynamics may cause near-bottom fluctuations in larval abundance. 97 RAPID ASSESSMENT OF TERRESTRIAL AND MARINE HABITATS USING TWO NOV- EL METHODS FOR ESTIMATING THE DENSITIES AND DISTRIBUTIONS OF ORGAN- ISMS G.K. Nishiyama and C.A. Kay. College of the Canyons, Department of Biology, Santa Clarita, CA 91355 Two novel plotless mathematical solutions for rapidly estimating the densities and distributions of organisms are proposed. The accuracy and precision of these estimations using these equations were compared to those obtained by methods commonly used in the field, including both line transect and nearest neighbor methods as well as stratified random quadrat sampling and belt transect sampling. The performances of both the novel and established methods were determined by estimating densities and distributions on simulations with varying sizes and dispersions of an organism. Field tests of the methods were then conducted in the chaparral habitat in Santa Clarita, CA as well as in the rocky intertidal zone at White’s Point, CA. In both the simulation and field tests, the proposed methods often produced more precise and accurate estimates of densities, and to a lesser extent distributions, than the other methods. The novel equations were also more robust than established methods in terms of more accurate density estimations when using varying sample sizes and organism dimensions. 98 ON SOUTHERN CALIFORNIA ABYSSAL ECHINODERMS K.D. Trego. Nautilus Oceanic Institute, La Jolla, CA 92037 Echinocrepis rostrata Mironov, 1973 is an abyssal echinoid found in the northwest Pacific and in the eastern Pacific from Alaska to Mexico at depths of 3315 to 5020 meters. There are two distinct morphological types, one in the northwest Pacific and one in the northeast Pacific south to 34° N. Specimens of FE. rostrata in the Scripps Institution of Oceanography Benthic Invertebrate Collection are of the morphological type found in the northeast Pacific. Cystocrepis setigera (A. Agassiz, 1898) is an abyssal echinoid found in the eastern Pacific from Alaska to Peru at depths of 2330 to 4100 meters. There is a collecting record for C. setigera in the central north Pacific at the Magellan Rise seamount (7° N 176° W; 3100 m). This is the only non-eastern Pacific record for this species and this may be due to the lack of sampling west of the eastern Pacific continental shelf. In the Peru trench C. setigera has a high level of ectosymbiosis; however, individuals of this species off the central California coast show that ectosymbionts are either extremely low in number or absent. Pythonaster pacificus Downey, 1979 is an abyssal asteroid described from a single specimen collected off southern California (31° 19.7’ N 119° 39.2' W; 3600 to 3676 m). An additional specimen of this species is in the Scripps Institution of Oceanography Benthic Invertebrate Collection (32° 03’ N 120° 30’ W; 3777— 3792 m). A live P. pacificus has been seen in camera sled imagery partially buried in mud (34° 42.11’ N 123° 11.185’ W; 4100 m). ABSTRACTS Si 99 THE DEEP SEA HOLOTHURIAN SCOTOPLANES GLOBOSA OFF SOUTHERN CALL FORNIA K.D. Trego. Nautilus Oceanic Institute, La Jolla, CA 92037 Scotoplanes globosa Théel, 1879 is a cosmopolitan deep sea holothurian found at depths of 545 to 7710 meters. The aggregate behavior of this species is well documented as mobile grazing aggregations of S. globosa feed on kelp falls, detrital deposits, and whale falls. The aggregate behavior of this species is also well documented in the Santa Catalina Basin and San Diego Trough. These are bathyal basins where S. globosa is found to be common. Scotoplanes globosa was studied in the Santa Catalina Basin by submersible at 1300 meters and in the San Diego Trough by at 1243 meters. Large numbers of S. globosa taken in single trawls may indicate aggregate levels present at the trawl sites. The Scripps Institution of Oceanography Benthic Invertebrate Collection has large single trawl lots for S. globosa from the San Diego Trough, Tanner Basin, and East Cortez Basin at depths between 1200 to 1400 meters. There is also a large single trawl lot for San Nicholas Basin at 1738 meters. Tanner Basin, East Cortez Basin, and San Nicholas Basin may be additional bathyal basins where S. globosa may be found in feeding aggregations. 100 TOOLS FOR TRACKING THE FATE OF WASTEWATER-DERIVED CONTAMINANTS IN EFFLUENT-DOMINATED WATERS David L. Sedlak. University of California, Berkeley, CA Municipal wastewater effluent contains low concentrations of a variety of chemical contaminants of concern to human health and aquatic ecosystems. Some of these compounds are difficult to measure with conventional analytical methods. To track the sources and fate of wastewater-derived contami- nants in surface waters, we have developed a suite of tracers that can be used to assess dilution and transformation reactions that occur in the aquatic environment. For example, enantiomers of the human pharmaceutical propranolol can be used to differentiate between untreated sewage and wastewater effluent because the compound undergoes enantiomer-selective degradation in wastewater treatment plants. This tracer can be used to identify sites where leaking sewers or combined sewer overflows impact water quality. Total organic iodine can be used as a tracer for the fraction of a water sample that is derived from wastewater effluent because the main sources of organic 10dine are the X-ray phase contrast media used in medical imaging. In a similar manner, wastewater-derived contaminants that are known to degrade by different mechanisms (1.e., reactive tracers) can be used to assess contributions of contaminants from combined sewer overflows and the transformation of contaminants by processes such as photochemical reactions and biotransformation. Application of these techniques should provide a better understanding of how wastewater-derived contaminants are attenuated in the aquatic environment and in engineered treatment systems. 101 , CONTAMINANT FATE AND SOURCE TRACKING USING CHIRAL AND STABLE ISO- TOPE ANALYSIS Kieth Maruya* and Peng, J.. SCCWRP, Westminster, CA; Zeng, E.Y., Chinese Academy of Sciences, Guangzhou, China Toxic organic contaminants continue to pose ecological and human health risks in coastal urban systems, however, identifying their sources and tracking their fate in complex watersheds remains challenging. For constituents of legacy and currently registered biocides that are chiral (e.g. DDT, toxaphene, cypermethrin), enantioselective GC- and LC-MS allows for quantification of enantiomer abundances/ratios, proxies for determining the extent of biotransformation acting on these compounds. Another powerful diagnostic tool is compound specific isotopic analysis (CSIA) where, for example, stable isotopes of carbon associated with individual chromatographic peaks are quantified after com- bustion to CO,. The underlying principle for applying CSIA is that stable isotope ratios (e.g. 5'C) shift when chemical bonds of the parent compound are broken, e.g. as a result of microbially-mediated enzymatic reactions. On the other hand, unchanging 6'°C values in a given watershed suggest little in situ transformation. These tools are being developed and applied in coastal environmental research to track and apportion contaminant sources, and to characterize the contaminant biotransformation po- tential of species, communities and ecosystems. Nn i) SOUTHERN CALIFORNIA ACADEMY OF SCIENCES 102 CHEMICAL METHODS FOR MEASURING BIOAVAILABILITY Jay Gan. Department of Environmental Science, University of California, Riverside In multi-phase matrices, phase distribution determines the bioavailability and hence the ecotoxico- logical effects of a contaminant. For a hydrophobic pollutant, it is well recognized that its availability for bioaccumulation or toxicity is reduced due to association with colloidal particles and dissolved organic matter (DOM). The reduction in bioavailability is influenced by both the quantity and quality of the colloidal and DOM phases. As the fine colloids and DOM are essentially inseparable from the aqueous phase, quantifying bioavailable concentrations is a great challenge. This presentation will discuss several tested physical-chemical approaches for measuring bioavailability of hydrophobic or- ganic contaminants, and their advantages and limitations. The second half of this talk will introduce solid-phase microextraction (SPME) and its unique applicability for detecting bioavailable concentra- tions. Studies show that SPME fibers mimic membranes or lipids of organisms, and chemical accu- mulation in the SPME fiber is parallel to bioaccumulation or toxic effects observed in test animals. SPME can therefore be used as a “‘biomimetic”’ surrogate to estimate contaminant bioavailability in sediment porewater, soil, runoff effluents, or ““brown”’ surface water. 103 WATER QUALITY ON SWIMMING BEACHES: NEW DIRECTIONS FOR THE EURO- PEAN UNION A. Staines. Urban Water Technology Centre, University of Abertay Dundee, Bell St, Dundee, DD1 1HG, Scotland, United Kingdom On 24 October 2002, the European Commission adopted a proposal for a revised Directive of the European Parliament and of the Council concerning the Quality of Bathing Water on swimming beaches in the European Union. This proposal is called COM 581 and is part of a sweeping 3™ wave of water directives, changing the face of environmental policy in Europe. Since the original directive was published there have been many changes to science, technology and the management of the environment. Within Europe since the early 1990s there has been a progressive move towards assessing water bodies holistically rather than just addressing human inputs and concerns. With new approaches, competent authorities such as water providers, environmental protection agencies and local authorities face new challenges to develop the systems that are prescribed in the new directive. Success in this is critical to best practice within coastal management and the associated social, economic and envi- ronmental aspects. The overall aim of my research is to develop methods and approaches to support the competent authorities involved, through a Bathing Water Management Framework (BWMBP). Using an inter-disciplinary model, this paper shall explore the three areas of greatest change in bathing water policy. These are: legislation and management development, biomonitoring, and communication to the public. This approach will ultimately lead to the development of a framework to assist competent authorities in improving management of beaches as entire ecosystems that are safe for human use. 104 CONTAMINANT TRENDS IN THE SOUTHERN CALIFORNIA BIGHT: A MUSSEL WATCH UPDATE A. J. Mearns and G. Lauenstein. National Ocean Service, National Oceanic and Atmospheric Administration, Seattle, WA and Silver Spring, MD Since 1986, mussels from about 21 sites in the Southern California Bight have been analyzed for trace contaminants as part of NOAA’s National Status and Trends Program. Recent data (through 2002 and 2003) show few significant changes to trends through 1998—1999 we reported in the 2002 SCAS conference. With one notable exception, concentrations of organochlorines (PCBs, DDTs and other pesticides) and butyltins (from antifouling paints) continued to decline through 2002/2003. Whereas concentrations of PCBs were below 200 ppb dw at most sites, those at two sites in San Diego harbor remained elevated above 1000 ppb dw. The highest concentrations of DDTs in 2002/2003 (753 ppb dw) occurred at San Pedro Fishing pier inside the LA/LB Harbor breakwater, with concentrations decreasing by 1—2 orders of magnitude upcoast and downcoast (e.g., 11.7 ppb dw at Point Loma). Nonetheless, since 1990 concentrations of DDT in mussels from all 21 stations declined an average of 53% (range 13 to 87%), giving a regional half-life of about 10 years. Chlordanes, heptachlors, and several other organochlorines compound classes remain measurable at low concentrations. Total poly- cyclic aromatic hydrocarbons (sum of over 40 PAHs) show continued elevated concentrations at ABSTRACTS Nn es) several sites, with fingerprints suggesting dominance of pyrolytic sources. Trace metal concentrations have changed little over the past two decades, with the notable observation of higher cadmium con- centrations at remote sites. Continued monitoring, coupled with comparison to chemical mass inputs from major sources (point, nonpoint) could reveal the effectiveness of pollution control efforts during the past two decades. 105 A COMPARISON OF TRACE METAL CONCENTRATIONS IN DEEP OFFSHORE AND NEARSHORE SEAWATER FROM SOUTHERN CALIFORNIA Richard Gossett. CRG Marine Laboratories, 2020 Del Amo Blvd, Torrance, CA 90501 An important route for the uptake of trace metals into marine organisms is dissolved metals directly from their environment. Results for trace metals using extraction/chelation followed by ICPMS anal- ysis will be compared between deep offshore seawater (800m) and nearshore harbor seawater. The concentration of several elements were significantly higher in the harbor water. The concentrations will also be compared to the several reference sources for seawater metals concentrations and the California Ocean Plan requirements. Finally, for the nearshore samples a comparison of the dissolved versus particulate metals concentrations will be presented indicating where the metals are partitioned. 106 HEAVY METAL ACCUMULATION IN SEA TURTLES FROM THE BAJA CALIFORNIA PENINSULA, MEXICO S.C. Gardner, S.L. Fitzgerald, B. Acosta Vargas L. Méndez Rodriguez. Centro de Investiga- ciones Bioldgicas del Noroeste, S.C., La Paz, Baja California Sur, Mexico Heavy metals were assessed in four species of sea turtles from the Baja California Peninsula, Mexico, representing the first report of heavy metal concentrations in tissues of post-yearling sea turtles from the Eastern Pacific. Concentrations of Cd measured in C. mydas kidney (652.57 g/g) were the highest ever reported for any sea turtle species. Cd accumulated preferentially in kidney and the range of kidney to liver Cd ratios in Baja California turtles were among the highest reported for sea turtles globally. Zn, Ni, and Mn concentrations were also significantly higher in kidney than other tissues, while Cu and Fe were greatest in liver, and all metals were lowest in muscle. With the exception of one value (69.9 pg/g in kidney of C. caretta), Pb was low in all tissues from Baja California. In comparisons across species, kidney of C. mydas had greater Zn and Ni concentrations as compared to other species, although there was no difference in liver metal levels among the species. Positive correlations were detected in the concentrations of Cd, Cu and Ni with the straight carapace length of C. caretta. Potential sources of high concentrations of metals in Baja California coastal ecosystems will be discussed and compared to the US State of California. 107. PROBING METAL-LIGAND INTERACTIONS USING STABLE ISOTOPICALLY LA- BELED PROTEINS AND DIRECTLY COUPLED HPLC-ICP-MS ‘ A.Z. Mason, T-M. Potter, J. Webster, and R.E Meraz. Department of Biological Sciences and Institute for Integrated Research in Materials, Environments and Society, California State Uni- versity, Long Beach, 90840, USA The transcriptional induction of metallothionein (MT) by reactive oxygen species (ROS) and ele- vated levels of metals such as Cd, Cu and Zn has been used to support the concept that this protein can be used as a sub-cellular biomarker for metal contaminant exposure and oxidative stress. Although not explicitly stated, the basic assumption in the use of the protein in this context is that the steady- state cellular concentrations of metallothionein qualitatively or quantitatively reflect the degree of contaminant exposure in a manner that the response can provide early warnings of deleterious sub- lethal effects. Conceptually, this paradigm is in accordance with the proposed protective function of MT in metal or ROS detoxification. However, more recent evidence indicates that this protein family may function primarily in metal homeostasis and the redox-mediated distribution of Zn in animal cells, implying that protein expression may be uncoupled from stressor exposure. The current work describes a novel ICP-MS procedure that has been used to directly probe the functionality of MT and the ability of the two major isoforms, MT-1 and MT-2, to exchange Zn and to selectively deliver Zn and Cd in a redox specific manner to intracellular protein targets, causing both enzyme activation and inactiva- tion. With further refinement, the technique has the potential for studying the synergistic and antag- 54 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES onistic interactions of different metals with multiple donor and recipient proteins. It therefore offers a procedural framework for empirically testing the behaviour of more complicated scenarios of metal- ligand exchange, which is the basis for understanding the cellular toxicity of essential and non-essential metals in vivo. 108 STRATIFYING BAY AND ESTUARY HABITATS OF THE WEST COAST OF THE CON- TIGUOUS USA: A STEP TOWARD REGIONAL INDICATORS OF BENTHIC COMMU- NITY CONDITION J.A. Ranasinghe', K.I. Welch’, PN. Slattery’, D.E. Montagne*, D.D. Huff’, H. Lee, II®, J.L. Hyland’, B. Thompson’, S.B. Weisberg', JM. Oakden*. 'SCCWRP, Westminster, CA; *Wash- ington State Department of Ecology, Olympia, WA; *Moss Landing Marine Laboratory, Moss Landing, CA; *County Sanitation Districts of Los Angeles County, Whittier, CA; °Oregon Dept. of Environmental Quality, Portland, OR; °US EPA, Western Ecology Division, Newport, OR; ’TNOAA, NOS, Charleston, SC; *San Francisco Estuary Institute, Oakland, CA We identified benthic assemblages occurring naturally in soft bottoms of bays and estuaries of the west coast of the contiguous US and evaluated the importance of geography and habitat in structuring them. Species abundance, habitat and contaminant data from 1318 samples collected by five regional and coast wide projects were adjusted for compatibility and combined. Because our objective was to define natural groupings of samples, potentially polluted sites were eliminated. Assemblages were then identified by hierarchical cluster analysis of species abundances in the 714 remaining samples. Lati- tude, salinity, grain size distribution and depth values were tested across dendrogram splits to assess whether the assemblages occupied different geographic regions or habitats. Overall, eight assemblages were identified, structured primarily by salinity, geography and sediment grain size. Geographically distinct high salinity assemblages were identified in southern California, Puget Sound and the west coast from central California to Washington State. In contrast, transitional salinity and freshwater assemblages were widely distributed along the coast. These assemblages may be viewed as alternate, habitat-dependent states of reference condition that can be used to identify impaired benthos. Most likely, regional indicators of benthic invertebrate community condition will differ from assemblage to assemblage. 109 INFESTATION OF PARASITIC GCOPEPODS AND THE POTENTIAL OF STRESS ON HOST FISHES Julianne E. Kalman. University of California Los Angeles, Department of Ecology and Evo- lutionary Biology, Los Angeles, CA 90095 and Orange County Sanitation District, Environ- mental Assessment Division, Fountain Valley, CA 92708 While it is widely known that the southern California marine environment has been subjected to numerous inputs of pollution, little is known about the effects of pollution on infestation of parasites on marine fishes. Exposure to pollution may result in stress, which may potentially decrease the immune response in fishes and increase their susceptibility to diseases and parasites. A variety of marine organisms have been evaluated as potential biological indicators of various forms of pollution in the aquatic environment. However, due to the range of contaminants to which marine organisms are exposed, it is unclear which organisms and which anomalies are best used as indicators. In addition, it is unclear to what degree parasites cause stress to their host and what long term damage occurs to host physiological responses. Chronic stress can inhibit an organism’s normal physiological response to the environment. Thus, fishes may be subjected to two major forms of environmental stress; parasites and poor water quality. The California scorpionfish, Scorpaena guttata, is common in southern Cali- fornia and is frequently infested with parasitic copepods. Intensity levels of parasitic gill copepods, Naobranchia scorpaenae, vary per host and can sometimes be as high as 100 copepods per gill cavity. Levels of the stress hormone cortisol and infestation levels of ectoparasites were compared from scorpionfish collected at various predetermined stations in southern California. Sampling occurred near the Orange County Sanitation District wastewater outfall. Preliminary results suggest an abnormal response in cortisol levels in groups of fish with high parasite prevalence. ABSTRACTS Nn Nn 110 DISRUPTION OF THE STRESS RESPONSE ENDOCRINE SYSTEM IN MARINE FISHES IN THE SOUTHERN CALIFORNIA BIGHT Kevin M. Kelley, Jesus A. Reyes, Kathy Sak, Shari Smolko, and Jeffery L. Armstrong*. De- partment of Biological Sciences, California State University, Long Beach, Long Beach, CA 90840; *Orange County Sanitation District (OCSD), Fountain Valley, CA 92708 Connections between environmental contamination and impairment of endocrine mechanisms reg- ulating key physiological systems in marine fishes are not understood, particularly in southern Cali- fornia. All vertebrates respond to environmental stressors via a highly integrated neuroendocrine re- sponse system which, in fish, is referred to as the hypothalamo-pituitary-interrenal (HPI) axis. Acti- vation of the HPI axis results in synthesis and release of the steroid hormone, cortisol, into the blood circulation and, depending on the nature and severity of a stressor and the fish species tested, plasma cortisol concentrations may increase up to 200-fold over basal levels. In our studies in fish from the Bight, we have identified instances in which the HPI axis shows severely blunted responses, including after conditions of chronic stress in captive fish and in fish captured in the vicinity of wastewater treatment plant outfalls. This impairment of the stress response system may occur at one or more levels of the HPI axis, in addition to possible alterations in steroidogenic or metabolizing enzyme expression. Our studies, aimed at these questions, will be addressed. 111 GROWTH ENDOCRINE DISRUPTION IN SOUTHERN CALIFORNIA MARINE FLAT- FISH Jesus A. Reyes and Kevin M. Kelley. Department of Biological Sciences, California State Uni- versity, Long Beach, Long Beach, CA 90840 Our research to date indicates that important endocrine systems may be altered in marine flatfish of southern California. One of these systems, that which regulates somatic growth and a host of related anabolic functions, is the insulin-like growth factor (IGF) axis. Increased circulating levels of IGF-I and IGF-binding protein-3 (IGFBP-3) promote growth, while decreased IGF-I levels combined with increased levels of IGFBP-1 are characteristic of growth inhibition. IGFBP-1 has a high IGF-I-binding affinity and blocks IGF-I activation of target cell receptors, and it is up-regulated by the stress hor- mone, cortisol. IGF-I expression and plasma levels, on the other hand, may be inhibited by cortisol, estrogens or other compounds. In flatfish caught in certain locales in the southern California bight, IGF axis alterations occur in individuals exhibiting impaired stress responsiveness (neuroendocrine HPI axis), while putative relationships between the IGF axis and plasma estradiol are less clear. 112 BIOACCUMULATION OF CONTAMINANTS IN RECREATIONAL AND FORAGE FISH- ES IN NEWPORT BAY, CALIFORNIA IN 2000-2002 M. J. Allen', D. W. Diehl', and E. Y. Zeng’. ‘Southern California Coastal Water Research Project, - Westminster, CA 92683; *State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, P.O. Box 1131, Guangzhou 51064, China Newport Bay is an important southern California estuary that is both a developed marina in its lower bay and an ecological reserve in the upper bay. Recreational anglers catch fish for consumption, particularly in the lower bay, and threatened bird species consume small forage fish in the upper bay. The objectives of this study are to |) provide recent data on contaminant levels in Newport Bay fishes, 2) identify species with concentrations posing potential health concern to humans or wildlife, and 3) identify species or ecological groups of fishes with high concentrations. Target contaminants included semivolatile organic compounds (DDTs, other pesticides, and PCBs) and trace metals (arsenic, mer- cury, selenium, and cadmium). Fourteen recreational and nine forage fish species were analyzed for these contaminants. Many fishes of Newport Bay have tissue contaminant levels above screening values (SVs) for human or wildlife fish consumption. DDT was the most widespread contaminant of concern in fish tissue, followed by PCBs. Five recreational fish species were above the human health SV for DDT and three for PCBs. All nine forage fish species were above the SV for wildlife health for DDT but only three were above that for PCBs. Three forage fish species had selenium levels above the wildlife SV. Although DDT was widespread in all species, other contaminants were asso- ciated with ecological types of fish. Although DDT, PCB, and selenium levels in some species are 56 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES still of concern, concentrations of these contaminants have declined substantially during the past 25 years. 113. OXIDATION OF SELENOMETHIONINE BY FLAVIN-CONTAINING MONOOXYGEN- ASES (FMOS) D. Shi and D. Schlenk. University of California, Riverside, Riverside, CA 92521 Selenium biotransformation into organoselenium forms by primary producers and subsequent ac- cumulation by higher food chain organisms such as fish are critical for mechanistically understanding the adverse effects of selenium in aquatic organisms. Although previous laboratory and field studies have both demonstrated a good correlation between adverse effects and total selenium in fish tissue, direct confirmation of the most toxicologically important forms of organoselenium is lacking, with nearly all measurement being total selenium. To illustrate this, we hypothesize that following accu- mulation by fish organoselenides are oxidized to selenoxides by flavin-containing monooxygenase (FMO) upon the consumption of NADPH and oxygen. The generated selenoxide can be reduced to organoselenide by consuming the antioxidant glutathione. With the continuous redox cycling between organoselenide and selenoxide we hypothesize, glutathione will be depleted eventually resulting in cellular toxicity. Therefore, in this study, an in vitro substrate dependent NADPH oxidation assay was performed to test the first step of the hypothesis, the oxidation of organoselenium by FMO. A series concentration of the organoselenide selenomethionine (0.05 2.0 mM) was incubated with 0.2 mM NADPH and 100 pg microsomal FMO1 or FMO3 proteins in 50 mM KPO4 buffer (pH 8.4) at 37 C. The absorbance of NADPH (340 nm) of the reaction mixture was measured over 30 min at 5 min intervals, and a NADPH extinction coefficient of 6220 M-1 cm-I! was used in calculating catalytic constants. The results show that both FMO] and FMO3 demonstrate catalytic activity for selenome- thionine, with FMO3 having a lower Km than FMOI (i.e, 172 pM and 617 pM, respectively), indicating that FMO3 is more reactive in catalyzing the oxidation of selenomethionine to the oxide. 114 ENANTIOSELECTIVITY IN PYRETHROID DEGRADATION IN SOIL S. Qin, M. G. Nillos, and J. Gan. University of California, Riverside, Riverside, CA 92521 Synthetic pyrethroids contain two or three chiral centers, making them a family of pesticides with the highest number of enantiomers. Our recent study showed significant differences in aquatic toxicity between the stereoisomers of the same compound. To better understand the ecotoxicological effect and fate of synthetic pyrethroids, chirality in biodegradation of pyrethroid compounds should be also considered. In this study, enantiomers of cis-bifenthrin were isolated on chiral HPLC and the enantio- pure isomers were examined individually for degradation rate in two soils under the same conditions. Degradation of each enantiomer was studied at 20°C under both aerobic and anaerobic conditions. The study results show that R-cis-bifenthrin degraded faster than S-cis-bifenthrin under aerobic con- ditions in both soils. However, under anaerobic condition, S-cis-bifenthrin was found to have a faster degradation rate. Isomer conversion did not occur during degradation in soil. As only biological interactions can be chiral selective, the enantioselectivity observed in degradation of cis-bifenthrin should be a result of different microbial communities under different test conditions. 115 ENANTIOMERIC SULFOXIDATION OF THE ORGANOPHOSPHATE PESTICIDE FEN- THION IN FISH O. Bawardi', B. Furnes, J. Rimoldi*, D. Schlenk'. 'University of California Riverside, Riverside, CA 92521; ?The University of Mississippi, University, MS 38677 The objective of this study is to examine the enantioselective sulfoxidation of fenthion, in liver microsomes of various fish species (rainbow trout, hybrid striped bass, tilapia). Microsomes from striped bass, trout, and tilapia primarily formed (-) sulfoxides in approximately 65% enantiomeric excess. Enzyme inhibitors lubrol (cytochrome P450) and methimazole (Flavin Monooxygenases) were used to determine sulfoxide relative contributions from each enzyme system. In striped bass micro- somes, P450 was responsible for 74% of sulfoxide formation. Co-incubation with methimazole or lubrol in trout liver microsomes enhanced sulfoxide formation. Salt water treatments which typically induce FMOs, did not significantly alter enantioselectivity or rates of fenthion sulfoxidation, even though toxicity tests indicated that saline environments enhanced the toxicity of fenthion in trout. ABSTRACTS a7 These results indicated either the formation of additional metabolites of fenthion or the contribution of additional oxygenases to S-oxidation. 116 LINKING BIOMARKER RESPONSES AND PHYSIOLOGICAL STRESS TO GROWTH IM- PAIRMENT OF CADMIUM-EXPOSED LARVAL TOPSMELT W. Rose!, R. Nisbet”, P Green?, S. Norris*, T. Fan*>, E. Smith!, G. Cherr', and S. Anderson’. 'Bodega Marine Laboratory, University of California Davis, Bodega Bay, CA; *Ecology, Evo- lution, and Marine Biology, University of California Santa Barbara, Santa Barbara, CA; *Civil & Environmental Engineering, “Land, Air, and Water Resources, University of California Davis, Davis, CA; °Chemistry, University of Louisville, Louisville, KY An integrated approach was used to determine if key biochemical, cellular, and physiological re- sponses were related to growth impairment of cadmium (Cd)-exposed larval topsmelt (Atherinops affinis). Food intake, oxygen consumption rates, apoptotic DNA fragmentation (TUNEL assay), and metallothionein (MT)-like protein levels, were separately measured in relation to growth of topsmelt aqueously exposed to sublethal Cd for 14 days. Cadmium accumulation and abundant metal concen- trations in topsmelt also were evaluated. Final mean weight and length of Cd-exposed topsmelt were reduced relative to those of control fish. Food intake was weakly correlated with weight of Cd-exposed topsmelt. Oxygen consumption rates were positively correlated with Cd concentration and inversely correlated with weight of topsmelt. Apoptotic DNA fragmentation was elevated in the gill of fish exposed to 50 ppb Cd, and in the gut, gill, and liver of fish exposed to 100 ppb Cd. Metallothionein- like protein levels were significantly elevated in fish exposed to 100 ppb Cd. Oxygen consumption rates may have increased as a compensatory response to Cd exposure; however, the energy produced was likely allocated to an increased metabolic demand due to apoptosis, MT synthesis, and ion reg- ulation changes. This diversion of energy expenditures could contribute to growth impairment of Cd- exposed fish. The integration of biomarker responses across levels of biological organization will advance our understanding of mechanisms through which fitness becomes impaired. 117. ARTHROGRYPOSIS FOLLOWING ACRYLAMIDE EXPOSURE jJ.G. Dahlgren', R.T. Schmidt’, and H.S. Takhar*. 'UCLA School of Medicine, Los Angeles, CA; *James Dahlgren Medical, Los Angeles, CA Arthrogryposis multiplex congenita (AMC) is a term that is used to describe the presence of multiple joint contractures at birth. AMC is a syndrome, involving many fetal and neonatal disorders of the neuromuscular systems. The mother of the subject worked in a biomedical laboratory using polyacryl- amide gels in electrophoretic studies of nucleic acids. Working without respiratory protection through- out her entire pregnancy, she experienced her greatest exposure to the monomer, acrylamide. Exposure to acryiamide throughout the mother’s pregnancy is judged to be the etiology of the subject’s arthro- gryposis. This is the first occupational prenatal exposure to the monomer acrylamide to be implicated as a possible etiologic agent in a case of arthrogryposis. 118 EXPRESSION AND CHARACTERIZATION OF CHANNEL CATFISH CYP 2X1 S. Mosadeghi, B. Furnes, C. Wong, D. Schlenk. University of California, Riverside, Riverside, CAN 92521 Previous studies of channel catfish identified a novel cDNA encoding the cytocrome P450 isoform, CYP2X1. To better characterize CYP2X1, the protein was expressed in Sf9 cells and examined for catalytic ability. A pFastBac ™ 1 donor plasmid, containing the CYP2X1 reading frame, was trans- ferred to the bacmid DNA (Baculovirus genome) at the Tn7 site-specific transposition in DH10Bac competent cells. Isolated microsomes from Sf9 cells demonstrated a maximum CO reduced spectrum at 450nm, and exhibited a band at approximately 57 kD on SDS-PAGE. CYP 2X1 catalyzed Benzphet- amine and Aminopyrine demethylase activity at 0.1888 nmol/min and 0.043 nmol/min respectively. However, enzymatic activity was not observed following incubation with p-Nitrophenol, Fenthion, Benzylresorufin or Pentoxyresorufin. These results indicate CYP2X1 displays activities consistent with other piscine CYP2 isoforms. 58 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES 119 IDENTIFYING ALUM AS A TOXICANT IN WHOLE EFFLUENT TOXICITY TESTS K. Rinaldi, P. J. Markle, C. Barton, E.X. DeHollan, and J.P. Bottomley. County Sanitation Districts of Los Angeles, Whittier, CA 90601 Alum (aluminum sulfate) is a commonly used flocculant in the wastewater treatment process. Dosing levels of alum are made at the discretion of POTW’s based upon several water quality factors. Chronic effects were observed in the cladoceran Ceriodaphnia dubia and the green algae Selenastrum capri- cornutum during routine testing of tertiary treated effluent from a municipal wastewater treatment plant. Several consecutive toxic samples prompted a Toxicity Reduction Evaluation (TRE) at the plant, whereby Phase I Toxicity Identification Evaluation (TIE) tests indicated higher sensitivity in Selen- astrum to the effluent than Ceriodaphnia, with no effects observed in Pimephales promelas. Filtration reduced the toxicity of the effluent in Phase I TIE tests using Ceriodaphnia, and subsequent Phase I TIE fingerprint tests of several compounds showed alum to produce patterns consistent to the effluent in terms of dose response, species sensitivity and toxicity reduction by filtration. The dose response levels appeared consistent with the average daily dose of alum at the treatment plant, and additional tests in which laboratory control water was diluted to match the hardness of the effluent showed even lower dose response levels in Selenastrum. The observed physical effects of alum on the green algae included clumping of multiple cells and decreased cell counts. This provides a possible mechanism for the chronic effects in Ceriodaphnia, which uses Selenastrum as a food source, and may explain the insensitivity of Pimephales to the effluent, which uses a larger, multicellular food source. Reduced alum dosing at the plant in response to this study appeared to confirm these findings, as subsequent effluent tests showed no chronic effects in either Ceriodaphnia or Selenastrum. 120 DEVELOPMENT OF A MACROINVERTEBRATE IBI FOR SOUTHERN COASTAL CAL- IFORNIA AND USE OF PROBABILISTIC SAMPLING FOR REGIONAL STREAM CON- DITION ASSESSMENTS P. R. Ode, A. C. Rehn* and J. T. May. California Department of Fish and Game, Rancho Cordova, CA We developed a macroinvertebrate index of biological integrity (IBI) for the arid and populous southern California coastal region. Potential reference sites were screened from a pool of 238 sites with quantitative GIS landscape analysis and with reach-scale physical habitat assessments. We eval- uated correlations among a suite of potential stressor gradients to identify a set of 10 independent reach, local and watershed scale stressors. To select component metrics for the IBI, we screened 61 candidate metrics for suitability with regard to three criteria: sufficient range for scoring, responsive- ness to the 10 stressor gradients and minimal redundancy with other responsive metrics. Seven final metrics (Percent Collector-Gatherer + Filterers, Percent Non-insect Taxa, Percent Tolerant Taxa, Co- leoptera Richness, Predator Richness, Percent Intolerant Individuals and EPT Richness) were scored and assembled into a composite IBI which was then divided into five equal condition categories. Three metrics had lower scores in chaparral reference sites than in mountain reference sites and were scored on separate scales in the IBI. A separate repeatability study and application of the IBI to an independent validation dataset confirmed that IBI scoring is highly consistent. Data from probabilistically selected sites allowed us to develop a defensible condition assessment for streams in the region. 121 ALGAE-NUTRIENT RELATIONSHIPS AND TMDL DEVELOPMENT IN MALIBU CREEK, CALIFORNIA S. L. Luce*!, R.E Ambrose? and M.A. Abramson!. 'Heal the Bay, Santa Monica, California. "University of California, Los Angeles, California Periphyton cover in Malibu Creek was sampled in spring and fall. Multiple regressions of periphyton cover with nutrients, canopy cover and substrate size indicated nutrient concentrations were most often related to periphyton cover, and canopy was the next most important factor after nutrients. Nutrient concentrations in the water and percent cover of periphyton were lower at reference sites than at impacted sites. Relationships between periphyton cover and nitrate concentration, phosphate concen- tration and canopy cover varied seasonally. Nitrate concentration had the strongest relationship with macroalgal cover in the spring and phosphate concentration had the strongest relationship with ma- ABSTRACTS 59 croalgal cover in the fall. Phosphate was consistently positively related to microalgal cover regardless of season. Nitrate was sometimes positively and sometimes negatively related to microalgal cover. 122 FRESHWATER STREAM INVERTEBRATES: RESPONSE TO PHYSICAL HABITAT AL- TERATION AND WATER QUALITY IMPAIRMENT IN SOUTHERN CALIFORNIA B.H. Isham*, B.T. Ferguson. Weston Solutions, Inc., Carlsbad, CA Biomonitoring of the benthic macroinvertebrate communities has become a widely used tool to monitor the effects of non-point source pollution in urban runoff. In coastal Southern California, physical alteration of natural drainages in the form of impervious surfaces and lined flood control channels has compounded the issues of biomonitoring, as the degraded physical habitats are not considered ideal for biological uses. Interpretation of biomonitoring results in drainages with physically altered habitats becomes difficult when water quality and physical habitat quality must be weighed to determine which has a greater effect on use attainability by the macroinvertebrate community. Three regional stream bioassessment monitoring programs were conducted in Los Angeles, Orange, and San Diego Counties in October of 2003 as required for municipal NPDES permit compliance. A total of 54 monitoring sites from 22 different watersheds were assessed using the California Stream Bioas- sessment Procedure (Harrington 1999). Data analysis incorporated a recently developed Southern Cal- ifornia Index of Biotic Integrity (Ode et al In Press) to rate quality of benthic macroinvertebrate communities. Physical habitat quality was quantified using EPA Rapid Assessment protocols. Results of our studies indicate that the biological integrity in urban affected watersheds in Southern California has been substantially degraded. We have also determined that while physical habitat may limit mac- roinvertebrate colonization to some degree, the lowest quality communities did not occur in the most altered or poorest quality physical habitats. Correlating the quality of the physical habitats of streams and the quality of the benthic communities they support indicates that there is little relationship in the presence of urban runoff. 123 THE APPLICATION OF STREAM BIOASSESSMENTS IN POINT AND NON-POINT SOURCE REGULATORY PROGRAMS Scott Johnson No abstract available. 124 USE OF IV SITU HATCHBOX STUDIES TO EVALUATE WATER QUALITY EFFECTS H. Bailey', B. Chalmers’, and J. Elphick'. 'Nautilus Environmental, San Diego, California; *Myra Falls Mine, Campbell River, British Columbia Laboratory toxicity tests have been criticized on the basis that their results may not reflect site- specific conditions. Conversely, interpreting the results of bioassessment studies may be problematic due to the inability to control for the movements of organisms in the receiving environment, as well as difficulties distinguishing between water quality and habitat effects. Thus, the use of in situ studies may provide an opportunity to quantitatively evaluate the potential effects of a discharge under the conditions found in the actual receiving environment. This presentation describes the approach used at the Myra Falls mine to evaluate the potential for discharge effects in the receiving environment. Eyed trout embryos were placed in hatchboxes at different locations to identify any potential for toxicity in Myra Creek. The reference site was located upstream of the discharge, and potential impact sites were located downstream of the discharge. Hatchboxes were also placed at selected locations to identify possible inputs of contaminated subsurface flows. Both lethal and sub-lethal endpoints were evaluated, including survival, hatching success, and growth. 125 THE EFFECTS OF SEQUENCING: MEMORY ITEMS VS. PERCEPTUAL LEARNING L. Calfas' and P. Kellman’. Marlborough School!', Los Angeles, CA, 90004; UCLA?, Department of Psychology, Los Angeles, CA, 90095 This study examined adaptive learning as it pertains to learning of memory items and perceptual learning. It studied how the order in which items are presented can be manipulated to make both types of learning more efficient. Fifty-four subjects completed a learning module that would teach thirteen 60 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES multiplication problems and thirty-nine subjects completed a learning module that would teach them to discriminate between ten categories of beetles. Subjects were randomly assigned to one of three conditions with different sequencing. One condition applied known laws of learning and memory of memory items to an adaptive learning algorithm that used speed and accuracy to determine which item to present. The other two conditions used random presentation. The results suggest that the adaptive learning algorithm allows for better retention than random presentation where the items no longer appear after they have been learned. Although retention is slightly better for random presen- tation where the items continue to appear after they have been learned over the sequencing algorithm, this requires far more trials than sequencing, making sequencing more efficient 126 CREB-MUTANT PERFORMANCE IN A NOVEL LEARNING TASK D. Chin. Alhambra High School, Alhambra, CA. Mentor: Dr. Amelia Russo-Neustadt The cAMP responsive element binding protein (CREB) is a nuclear protein that helps in transcrip- tion of brain-derived neurotrophic factor (BDNF). Through a series of intracellular signaling events CREB activates transcription of genes with cAMP responsive elements in their promoter regions. BDNF is a neurotrophic factor transcribed within brain cells that has been shown to play a vital role in learning and neuronal survival. CREB impairment would therefore inhibit memory and recognition in mutant mice. In this experiment the Y-Maze was used to test the extent of the effects of novelty versus experience on performance in the Y-Maze and its effect on BDNF levels in mice. Results acquired so far are somewhat significant. CREB mutants were injected with 4-hydroxy tamoxifen to activate the CREB repressor. Although in some cases mutants performed just as well controls, in most cases control mice performed noticeably better than mutants. 127. OPERATIONAL EFFECTS OF ALTERED ABIOTIC FACTORS ON NITRIFYING BACTE- RIA: YEAR 2 Sanjit Datta. Palos Verdes Peninsula High School and Cabrillo Marine Aquarium, San Pedro, CA 90731 A way to easily determine the feasibility of any method of preserving water quality in a specific water body 1s critical for the large-scale implementation of the method. Artificial addition of nitrifying bacteria to a water body can efficiently lower concentrations of ammonia, a highly toxic nutrient. A set of abiotic factors with respect to temperature, pH, salinity, and dissolved oxygen under which the bacteria can be expected to operate optimally would be instrumental in helping naturalists considering adding nitrifying bacteria to a natural water body make the decision. The experiment was done by changing abiotic factors in tanks containing Nitrobacter and Nitro- somonas and water collected from Salinas de San Pedro, a salt marsh. The success of the bacteria was determined by testing concentrations of ammonia and nitrates. It was hypothesized that only salinity will have an effect on the bacteria. The results showed that this was incorrect. The two genera of bacteria in the Biozyme favored different conditions of abiotic factors. Overall, the optimum water body for the nitrifying bacteria to operate in would have a temperature of about 30°C, a pH between 8.0 and 8.3, a salinity between 22 and 27 ppt, and a dissolved oxygen content between 5 and 9 mg/L. It should be noted, however, that in almost all cases, the bacteria operated as it should under unfavorable conditions, although its processes were somewhat delayed. 128 STRAIN RELATEDNESS OF CANDIDA IN HUMANS: A URINARY PATHOGEN OR COLONIZER? (PHASE 2) Joon-Bok Lee. Division of Infectious Diseases, Los Angeles County Harbor-UCLA Medical Center, 1000 W. Carson Street, Torrance, California 90502 Candida species are commonly found the urine of hospitalized patients. Over 50,000 persons have this condition annually in the United States. This significance of this condition, candiduria, remains controversial. There is evidence that candiduria may represent a potentially serious and deadly blood- stream infection, or, alternately, merely represent urinary tract colonization. To provide important insights into the meaning of this condition, we examined strain relatedness of Candida strains from ABSTRACTS 61 over 300 patients causing infections among hospitalized patients of Harbor-UCLA Medical Center last year. METHODS: We longitudinally examined 300 hospitalized patients with candiduria from Cedars Sinai Medical Center. Among those with > 1 Candida strain isolated from the urine, we compared strain relatedness using usual clinical microbiological techniques and DNA fingerprinting. We hy- pothesized that Candida species would vary over time, suggesting that candiduria may represent host susceptibility to this condition rather than a persistent state. RESULTS: Among the 300 patients, 89 had > | analyzable candida strain. Mean number of cultures per patient was 2.787. Of these follow-up cultures (cultures done after the initial culture positive for candida), 54 were negative for Candida, 47 demonstrated a different Candida species or strain and 147 demonstrated the same Candida species and strain. Four patients went on to have bloodstream infections. CONCLUSIONS: Candida in the urine tended to wax and wane with time, and occasionally are supplanted with other Candida strains. This demonstrates that candiduria commonly resolves and recurs, occasionally with a new species. This suggests that candiduria, rather than persistent, phenom- enon and that the natural history of this process appears relatively benign in most cases. 129 MAINTAINING CORRECT BALANCE: SPATIAL CODING AND ITS DEPENDENCE ON NATURAL STIMULI D.E. Lluncor. Palos Verdes Peninsula High School and David Geffen School of Medicine at UCLA, Division of Neurobiology Head and Neck Surgery Laboratory of Vestibular/Sensory Neurobiology, Los Angeles, CA 90095 The vestibular system in the inner ear decodes motion and acceleration. The utricle’s otoconia deflect hair-like protrusions in ascending order, called the morphological polarization vector. MPVs are es- sential for spatial coding. The project examined what effect natural stimuli have upon MPV mainte- nance. Otoconia deficient HET/HET and otoconia producing HET /+ mice utricles were used. Thus, otoconia was the sole variable. The tissues were prepared with phaloidin fluorescence and were imaged with a confocal microscope. The angle was calculated using the kinocilium center and hair cell center. In data quantification, three similar utricle areas yielded a HET/+ to HET/HET average angle of 93.3° to 105.5°, 114° to 137.5°, and 91° to 100° respectively. The compared MPV angles showed similarity, which suggests that sensory coding is non-stimuli dependent. This experiment deductively narrowed the factors contributing to MPV maintenance, so that non-stimuli factors can be explored. 130 EFFECTS OF ATMOSPHERIC CARBON DIOXIDE ON THE NITROGEN FIXATION CA- PABILITIES OF TRICHODESMIUM S.F. Ong, J. Sohm, and D.G. Capone. California Academy of Mathematics and Science, Carson, CA 90747; Wrigley Institute for Enviromental Science, University of Southern California, Los “Angeles, CA 90098 As a consequence of the rising levels of anthropogenic carbon dioxide in the atmosphere, the world ecosystems are undergoing unforeseen changes. The nitrogen cycle constitutes as one of the most important processes within the biological world, with nitrogen being one of the twenty-five necessary elements for life. Therefore, it is essential to understand of future marine ecosystems in regards to organic nitrogen influx. Here, the effects of increased atmospheric carbon dioxide on the nitrogen production capabilities of Trichodesmium, a marine cyanobacterium responsible for the majority of the nitrogen supply in its ecosystems, are measured. By taking advantage of the inverse relationship between pH and CO, absorption, Trichodesmium cultures were designed to grow in CO, conditions of the pre-industrial era, the current era, and predicted levels for the years 2060, 2180, and 2250. Per trichome, nitrogen fixation rates were found to sharply decrease by 2060 and level out for the future. Rates, accordingly to the results found, are the highest within the range of time studied. However, rates per mL were found to be in direct opposition, with rates increasing linearly from 2060 onward. Therefore, an increase in organic marine nitrogen influx can be expected to occur in the future if anthropogenic CO, continue to rise unabated. The consequences of this augmented nitrogen supply are unknown. The results from this particular research represent only one piece of the huge puzzle that constitutes the question of the effects of anthropogenic carbon dioxide on marine nitrogen cycles. 62 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES 131 USING THE INHIBITORY EFFECTS OF ATP ANALOGS TO REGULATE MRNA PRO- CESSING: YEAR II Carol Y. Suh. Palos Verdes Peninsula High School, and University of California, Los Angeles, Department of Chemistry and Biochemistry, Los Angeles, CA 90095 A key element in gene expression, post-transcriptional processing proves to be essential for the vitality of a cell. Processing includes cleavage of the pre-mRNA and the addition of the poly(A)tail, which stabilizes the mRNA for transport outside of the nucleus in order to be translated into a protein. Defects in processing regulation are involved in diseases such as HIV/AIDS, thalassemias (a blood disorder), and can even play a role in tumor cell viability. Recently, an in vitro coupled processing system that mimics processing in vivo has been created in our lab. During the development of this system, it was suspected that Cordycepin triphosphate (3°dATP), an ATP analog, inhibited cleavage and polyadenylation of RNA. This inhibitory effect implied that ATP might play an important role in mRNA processing. To assess the role of ATP in mRNA processing, ATP analogs 3’dATP and Ara-ATP were introduced to coupled and uncoupled processing systems in pulse-chase assays. It was found that inhibition of processing was specific to ATP analogs. 3’dATP inhibited processing up to 254M and Ara-ATP decreased processing efficiency by 43.5%. Data suggest that these ATP analogs interact at an allosteric site, thereby inducing a nonfunctional conformation, preventing processing. ATP interacts with proteins on the processing apparatus thereby regulating processing. ATP-dependent regulation of cleavage and polyadenylation supports the new idea that the processing reactions are intertwined to efficiently express genes. In addition, harnessing this inhibitory effect from ATP analogs can be used to regulate over-expressed genes that cause diseases. 132. STUDY OF THE EFFECTS OF WEURAL LAZARILLO OVEREXPRESSION IN TRANS- GENIC DROSOPHILA MELANOGASTER Derek Tam. Alhambra High School. Mentor: Julien Muffat (laboratory of Pr. Seymour Benzer) This project is aimed at discovering the effects of the overexpression of Neural lazarillo (NLaz) in Drosophila. Overexpression results in additional proteins of a certain gene being present in the or- ganism. Previous research with a close homolog, Glial lazarillo, have led us to hypothesize that overexpression will increase lifespan and resistance to environmental stress. The human homolog of the two genes is Apolipoprotein D (ApoD). Its function is unknown, but it is upregulated in brain pathologies. We want to determine whether Nlaz can help slow aging in fruit flies or prevent neuro- degenerative diseases, and gain a better understanding of ApoD in humans. I began by acquiring samples of Nlaz cDNA in plasmids, or bacterial vectors. Then the plasmids were transfected by electroporation into E.coli and several colonies were cultivated, replicating the vectors, which were then extracted by Miniprep. A restriction digest was conducted to cut out Nlaz. The Nlaz cDNA fragment was separated from the plasmid DNA by electrophoresis and will be cloned into the plasmid pUAST, which allows conditional expression in Drosophila. Once the final plasmid is constructed, it will be injected into Drosophila embryos. After careful selection we will obtain flies carrying the pUAST-NLaz transgene in their genome. These will be crossed to drivers to trigger the expression of NLaz with spatio-temporal control. I will test the progeny for increased lifespan and resistance to stresses (e.g. heat, hyperoxia). Results from this project will help us understand the role of ApoD in human aging and neurodegeneration. 133. 3D MODEL OF ALGORITHM PERFORMANCE ON THE 3-SATISFIABILITY PROBLEM Timothy Uy, California Academy of Math and Science, and Dennis Kibler, Department of Computer Science, University of California: Irvine, Irvine, California 92697-3425 The Satisfiability problem consists of variables with two solutions: True or False and clauses com- prising of variables connected through OR operators. In some instances, NOT operators are situated at the front of variables, negating variables. All clauses are further linked to one another using AND operators. Using two algorithms, a model is created to analyze the performance. The two algorithms are the simulated annealing algorithm and a variant of the simulated annealing algorithm. These two algo- ABSTRACTS 63 rithms were chosen because of its extremely high performance compared to the hillclimbing and genetic algorithm. Due to the diversity of satisfiability problem, the experimentation was tested with a ratio of ap- proximately 4.25:1. This creates a equal divide in solvable and unsolvable problems. The experiment was tested on three problems consisting of four variables and ten clauses. It is then modeled to analyze its performance on a small scale in order to incorporate it into larger scale problems. The satisfiability problem is significant in many ways because of the NP-complete nature of the problem. By generalizing an efficient way to solving this problem, it can be applied to problems that have the same NP-complete property. 134. PROSTATE CANCER PREVENTION BY POLYPHENOLIC COMPOUNDS IN GREEN TEA Elysia Chin. Alhamnbra High School and University of Southern California, Keck School of Medicine, Los Angeles, CA 90033 Cancer is known to be one of the leading causes of death, and of those deaths, 40,000 cases are attributed to prostate cancer. In this study of chemoprevention for cancer, RWPE-1 prostate epithelial cells were used in conjunction with epigallocatechin gallate (EGCG), which is a major polyphenolic compound of green tea. Very recent studies have shown that green tea might possess factors, especially certain polyphenolic compounds, that would further the research for chemoprevention. In this particular experiment, EGCG is speculated to be able to inhibit protein kinase C (PKC), which is a receptor for tumor promotion. The RWPE-1 precancer cells were infected by EGCG and grown in soft agar. The cells then underwent several scintillation counter exams. Each test was aimed to find distinct data and results that proved EGCG could indeed inhibit PKC. The correlation between the concentration of EGCG used and the number of active cells and colonies supports this experiment’s hypothesis and further confirms recent queries about the possibility of using green tea for future chemoprevention. 135 IMPORTANCE OF DROSOPHILA EIF4E-BINDING PROTEINS IN LIFESPAN REGULA- TION Tony Au Lu. Alhambra High School. Mentor: Brian M. Zid; Teacher: Mr. Duane Nichols Aging is unclear to scientists worldwide and yet people continue to be interested in ways to live longer; in Drosophila, when insulin levels fall, due to either genetic interventions or lack of nutrients a lifespan extension is seen. My previous research suggests that longer lifespan correlates with acti- vation of the dFoxo gene, which is regulated by insulin levels, and reduced amounts of nutrients. This project therefore tests whether or not 4E-BP, which is downstream of the dFoxo pathway, is responsible for the increase in lifespan. Thus, it is hypothesized that if there is a lack of nutrition and if 4E-BP is upregulated, then 4E-BP will stimulate an increase in lifespan. In this study, Drosophila lifespan was studied with respect to various overexpressions of 4E-BP that differ in their composition of Gal4d— PO163, or 109—drivers, which are Drosophila lines that express the yeast transcriptional activator Gal4 in a tissue specific manner. In addition, the Drosophila were fed protein in the form of yeast ranging from 0—4% yeast concentrations. I saw complex interactions between the levels of 4E-BP and the nutritional content of the food for the phenotype of lifespan. The results show overexpressed 4E- BP on low yeast has a 50% increase in lifespan while 4E-BP on high yeast, a 15% decrease in lifespan. Because the Drosophila genome shares 77% of their genes with the human genome, these findings may be applied to increasing human lifespan and allow us to study human mortality. 136 MOTHER’S CHARACTRISTICS AND HER CHILD FEEDING HABITS April Stephenson and Maivy Nguyen. Dr. Fary Cachelin, California State University Los An- geles, Department of Psychology, Los Angeles, CA 90041 Obesity is one of the fastest growing public health problems in America. It has been established that weight problems in childhood lead to significant health problems later in life. Parents are the strongest and most direct influence on their children’s eating habits, and eating habits that are estab- lished in childhood often persist through adulthood. By surveying mothers of diverse ethnic and socioeconomic backgrounds, correlations can be found that indicate which characteristics possessed by the mother influence her child feeding habits. Several such variables have been studied by the use of surveys. The socioeconomic status of the 64 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES mother, her depression, body dissatisfaction and acculturation all affect her feeding habits and thus her child’s eating habits. Her influence is determined by considering her restriction of her child’s eating, the pressure she places on her child to eat, her perceived feeding responsibility, her concern about her child’s weight and how closely she monitors her child’s eating. The study found that there iS a positive correlation between the socioeconomic status of the mother and the pressure she puts on her child to eat. There were also negative correlations found between her acculturation to American society and her perceived child feeding responsibility and, again, the pressure she puts on her child to eat. These findings are important to discovering which mothers are more likely to misguide their children’s eating habits and how mothers can be educated in helping their children make intelligent eating decisions for the rest of their lives. 137 ROLES OF AUXOTROPHIC MARKERS IN CANDIDA ALBICANS VIRULENCE D. Im, California Academy of Math and Science, and H. Park. Division of Infectious Diseases, Department of Medicine, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA 90502 Candida albicans is the most common human fungal pathogen that causes mucosal and disseminated infections. This dimorphic fungus, which exists as oval, single yeast cells but forms hyphae under favorable conditions, is the most common cause of yeast infections. The virulence factors, which determine the ability of C. albicans to cause damage to its host cells, will serve as promising targets for therapies against Candida infections. Therefore, we examined the nutrient auxotrophy as a potential modifier of virulence in C. albicans. In order to determine the effects of auxotrophy for uracil, arginine, and histidine on virulence traits of C. albicans, BWP17 (Ura Arg His) strain was used as a parental strain to construct Ura* Arg” His” strains, Ura*Arg*His~ strains, and Ura*Arg*His* prototrophic strains. To examine the ability of each newly created strain to express the virulence related traits, growth test on different selection media, hyphal formation, and endothelial cell damage assay were performed. Ura* Arg His’, Ura*Arg*His-, and prototrophic strains formed hyphae while BWP17 could not. The abilities of the newly constructed strains, which all are prototrophy for uracil, to cause damage to endothelial cells were significantly higher than that of BWP17. Therefore, prototrophy for uracil is essential for the full virulence traits of C. albicans. On the other hand, auxotrophy for arginine and histidine does not affect the virulence traits. In conclusion, inhibiting the production of uracil may be used to develop therapeutic agents that specifically target Candida infections. 138 PREDICTING MATERIAL FAILURE: CORRELATION BETWEEN DEFORMATION LU- MINESCENCE AND HYSTERESIS Geoffrey H. Woo. UCLA, Department of Physics and Astronomy, Los Angeles, CA 90095-547 Prediction of material failure would advance solid-state physics and revolutionize modern engi- neering. Scientists and commercial systems, currently, are unable to measure the impact of stress and, most importantly, to predict system failure. The objective of this study is to discover the molecular changes of materials under stress by analyzing the characteristics of deformation luminescence (DL). Such discovery leads towards the ultimate goal of predicting material failure. Mechanoluminescent irradiated Lithium Fluoride (LiF) crystals were utilized in various experiments to investigate deformation luminescence as the material undergoes hysteresis, specifically the variables of stress, strain, load speed, and time duration. An Instron testing system was used to compress LiF at various loads, speeds, and cycles. Photomultipliers were used to capture photon emission data. Data was collected both manually and with an oscilloscope computer data acquisition system. Mathematical models were derived. As LiF was stressed beyond its elastic limit, light was found to increase drastically in various mathematical functions against stress, strain, and time duration, signaling hysteresis. DL increases logarithmically to load speed. Accumulative total of photon emissions was found to be an accurate assessment of material health. DL was also found to be effective in detecting the presence of internal cracks and denoting the phenomena of fracture. DL was found to be a superior indicator of hysteresis, the precursor to failure. The discoveries made in this study form the basis of a reliable failure prediction system. The findings will ultimately improve the safety and efficiency of vehicles, machines, and structures we use today. ABSTRACTS 65 139 CHANGES IN DENSITIES OF FECAL INDICATOR BACTERIA (FIB) OVER DIFFERING TIDAL FLOWS IN THE BALLONA WETLANDS, LOS ANGELES S. Yanamadala! and John H. Dorsey’. 'Chadwick High School, 26800 S. Academy Drive, Palos Verdes Peninsula, CA, 90274, and *Loyola Marymount University, Department of Natural Sci- ences, Los Angeles, CA 90045 There are two main objectives of this experiment: 1) to create a mathematical model showing the relationship between turbidity, dissolved oxygen, pH, salinity, time from high tide, and levels of indicator bacteria for fecal contamination, and 2) to see if fecal indicator bacteria (FIB) densities differ with tidal flows from flood to ebb. In the field samples were tested at a single location every half hour during 12-hour periods on 3 occasions for temperature, dissolved oxygen, and pH levels using the YSI 600R Sonde Electronic Probe. In the laboratory, turbidity was measured using a HACH 2100N turbidity meter, and densities of FIB (total coliforms, FE. coli, enterococci) were determined using IDEXX Quantitray 2000 test kits and reagents based on enzyme substrate methods. A mathematical model was created showing the relationship between dissolved oxygen, turbidity, pH, salinity, time from high tide, and bacterial growth. Results indicated that bacterial levels were higher with decreased dissolved oxygen, decreased sa- linity, and increased turbidity in a neutral pH. As bacterial levels rose, the dissolved oxygen and salinity reserves were depleted. Turbidity levels appear to increase as sediments are drawn off of the banks of the water column and resuspended from the bed of the creek. FIB appear to attach to the sediment particles, thus are drawn into the water as turbidity increases. FIB levels were also higher at and around high tide. This study suggests that sophisticated mathematical models can be constructed to integrate testing parameters. As more v ariation around these parameters is explained through modeling, then fewer key parameters could be measured in the future, thus reducing the costs for monitoring programs. 140 POLYPHENOL EFFECT ON SUSCEPTIBILITY OF OXIDIZED B-AMYLOID PEPTIDE TO INSULIN DEGRADING ENZYME J. Young. Alhambra High School and USC Keck School of Medicine, School of Pharmacy, Department of Pharmaceutical Science, Los Angeles, CA 90089 Oxidized amyloid-f proteins (AB) play an important role in the pathogenesis of Alzheimer’s disease and are the cause of neuronal deaths. This study tested whether polyphenols, antioxidants in green tea, had an effect on the susceptibility of oxidized AB to protease digestion by insulin-degrading enzyme (IDE), a major A®-degrading enzyme. 2 sets AB,. peptides were oxidized with NBS and Cu+ +/ H,O, in either green tea extract, a major source of polyphenols, or aqueous solvent. The AB peptides were lyophilized and resuspended and then desalted using C18 spin columns. A BCA protein assay was used to determine the recovery of AB from the columns. Green tea and non-green tea incubated AB,, were subjected to proteolysis with IDE or trypsin. AB samples were electrophoresed and were analyzed by Western Blot and the results were captured on x-ray film. This study concludes that IDE and trypsin’s proteolytic ability towards oxidized AB, incubated in green tea are increased as compared to standard oxidized AB, . Both enzymes also exhibited increased proteolsis towards the AB4 peptides when higher concentrations of enzymes were added to the sample. Polyphenols in green tea were able to reduce or prevent the oxidation of AB4o, thus allowing enzymes to degrade the peptides without complications. 141. EFFECTS OF SALINITY CONCENTRATION ON RATES OF POLYP CLONING, GROWTH, AND STROBILATION IN THE AURELIA LABIATA (CNIDARIA, SCYPHO- ZOA) Julie A. Guerin. Cabrillo Marine Aquarium, San Pedro, CA 90731; (Palos Verdes Peninsula High School, Rolling Hills Estates, CA 90274) The purpose of this study was to determine how increased and decreased salinity concentrations affect the developmental asexual stage in the life cycle of the Aurelia labiata. This species of jellyfish is known to be adaptable in the changing marine environments of coastal ecosystems, but environ- mental factors could influence their reproduction rates. After culturing from fertilized eggs, 10 similarly Pie ALE (yr ear) botele_eege, 5e teen lui 9 auras armanget gh de ris * ‘me SP ie eile, ag laie a+ rath tal Jeeta ieee (WL tienes, i lalate Aeon Jae on hers Ri : ate wtp aun velit. ei £ OA Gr Spy ub eet = 18 - a ¢ : bd. om ‘ ‘a : ae . ‘va Sl oe barag, + et : ; en @ Sete seg! barat ee , %, treed a Si Se Ss (yp ra 7 7 «2t® [o Name M. James Allen R.FE. Ambrose Joan Backey H. Bailey Craig Barilotti O. Bawardi Lyall Bellquist Tom Benson S. Bondarenko Peter Brand R.L. Budd Leslie J. Buena Lisa Calfas Andres Carrillo Daniel Chin Elysia Chin Kevin Clark Charles Collins Charles Collins Kelly Connell Dan Cooper Ken Corey Mike Curtis J.G. Dahlgren Sanjit Datta Andrew C. Davenport John G. Douglass Ryan Ellingson Richard F. Feeney Lanny H. Fisk T. Ford i Froeschke Francis M. Fujioka Jay Gan S.C. Gardner Doug Gibson Christine Goedhart Alphabetical List of all Presenters. Abstract no. 112 10 30 124 14 LS 20 81 4] 117 127 17 a5 47 Armando Gonzalez-Caban 72 Richard Gossett D. Greenstein Julie Guerin Angela Guo Shannon Harsh Sarah K. Henkel Lawrence Honma Edgar H. Huerta W. Hunter Da Eun Im B.H. Isham 105 48 141 143 49 50a py) 36 50b 137 122 Name Abstract no. Steven R. James 32 J. Jay 66 Ami Jenkins 51 P Jensen 67 Scott Johnson 123 Sanyl Kabre 142 Julianne Kalman 109 Kathy Keane 88 Kathy Keane 85 Kevin M. Kelley 110 Peter Koenig 94 Jerry Kwong 144 Henry C. Koerper 34 Brian W. Kot 52 E: Bruce Lander 39 Frederick Lange oH Joon-Bok Lee 63 Joon-Bok Lee 128 Dennis C. Lees 15 Danielle Lipski 2 David Lluncor 129 Mickey Long 86 Katherine Lu 143 Tony Au Lu 135 Sl iouce [2t Karen Martin 53 K. Maruya 101 Zed Mason 107 M. Mcllhinney 1 Jeanette A. McKenna 33 Alan J. Mearns 104 L. Mendez 68 Laura Merrill TI Kathy C. Molina 82 Kathy C. Molina 90 Robert Mooney 9 S. Mosadeghi 118 Marci Narog 78 Danielle Neumann 26 Gregory Nishiyamna OF Chris Nordby 5 Christopher T. Oakes 54 Su F. Ong 64 Su F Ong 130 Gregorio Pacheco-Ambriz 40 Mark Page 12 Ed Parnell 18 Daniel Pondella US Justin Pritchard 58) Name S. Qin Ananda Ranasinghe Dan Reed Jesus A. Reyes Jennifer L. Reche A.C. Rehn Philip J. Riggan K. Rinaldi Y. Rodriquez W. Rose Allison Roth Donna M. Schroeder David L. Sedlak Mike Shane D. Shi Craig S. Shuman Mary Small Mary Small Kathleen Snow M.A. Sorensen A. Staines Eric Stein April Stephenson Carol Y. Suh Derek Tam Brian Travis Kent D. Trego Kent D. Trego Jim Trout Timothy Uy Tracy Valentovich D.E. Vidal Richard Vogl Sean E. Walker Chris Webb L. Wenjian Demian Willette Peter M. Wohlgemuth Geoffrey H. Woo Swati Yanamadala Swati Yanamadala W. Yang D.L. Young John Young John Young Richard Zembal Richard Zembal Barbara Ziegler Abstract no. 114 108 13 ee 76 120 75 ae, 56 116 49 16 100 yg) IB ) SCAS News, Acknowledgements inside front cover SCAS Board Members and Officers inside front cover Research Training Program inside front cover Student Award Winners Schedule of Program for the 2005 Annual Meeting Abstracts Alphabetical List of Presenters at 2004 Annual Meeting COVER: Seal of the Academy. Serials QH ISSN 0038-3872 1 S69 v.104 no.3 24116-40 Peete kN VC ARIPORNIA ACADEMY) OF SCIENCES BOLLET Volume 104 Number 3 et Fo ae en ay aaa rs Ft secs RE 4 hed pee fun oy 4 BCAS-A104(3) 113-158 (2005) December 2005 Southern California Academy of Sciences Founded 6 November 1891, incorporated 17 May 1907 © Southern California Academy of Sciences, 2005 OFFICERS John Dorsey, President Brad Blood, Vice-President John Roberts, Secretary Daniel A. Guthrie, Treasurer Daniel A. Guthrie, Editor Ralph G. Appy, Past President Robert Grove, Past President David G. Huckaby, Past President Daniel J. Pondella, Il, Past President BOARD OF DIRECTORS 2003—2006 2004—2007 2005—2008 M. James Allen Brad Blood Jonathan N. Baskin John H. Dorsey Donald G. Buth John Roberts Judith Lemus Robert S. Grove Gloria J. Takahashi Karen Martin Kathy Keene Andrea Murray Susan Yoder Edith Reed Phillippa Drennan Membership is open to scholars in the fields of natural and social sciences, and to any person interested in the advancement of science. Dues for membership, changes of address, and requests for missing numbers lost in shipment should be addressed to: Southern California Academy of Sciences, the Natural History Museum of Los Angeles County, Exposition Park, Los Angeles, California 90007-4000. Professional Members.) 2. 8. es a es SS Student Members’ 2 3008 2 a EO te BS a Og i er Memberships in other categories are available on request. Fellows: Elected by the Board of Directors for meritorious services. The Bulletin is published three times each year by the Academy. Manuscripts for publication should be sent to the appropriate editor as explained in “Instructions for Authors” on the inside back cover of each number. All other communications should be addressed to the Southern California Academy of Sciences in care of the Natural History Museum of Los Angeles County, Exposition Park, Los Angeles, California 90007-4000. Date of this issue 22 December 2005 This paper meets the requirements of ANSI/NISO Z39.48-1992 (Permanence of Paper). ANNUAL MEETING OF THE SOUTHERN CALIFORNIA ACADEMY OF SCIENCES DRESCHER GRADUATE CAMPUS OF PEPPERDINE UNIVERSITY, MALIBU, CALIFORNIA May 12-13, 2006 FIRST CALL FOR SYMPOSIA AND PAPERS The Southern California Academy of Sciences will hold its annual Meeting for 2006 on the Drescher Graduate Campus of Pepperdine University on Friday and Saturday May 12-13. The meeting will be held in conjunction with the California Estuarine Research Society (CAERS) and the Society of Environmental Toxicology and Chemistry (SETAC). Both these societies will hold symposia in addition to those listed below. Presently the following symposia are in the planning stages. If you would like to organize a Symposia for this meeting, or have suggestions for a symposia topic, please contact John Dorsey at jdorsey @; mu.edu or Brad Blood at bblood@psomas.com. Organizers should have a list of participants and a plan for reaching the targeted audience. Proposed Symposia for 2006 Southern California Archaeology: Andrea Murray; amurray @exchange.fullerton.edu Ecology of Nearshore Reefs: Daniel Pondella; pondella@oxy.edu and Bob Grove; grovers@sci.com Avian biology; Kathy Keane; keanebio@cs.com Southern California Paleontology: Mark Roeder; mroeder! @earthlink.net Additonal Symposia on Marine Protected Areas, Parasitology, Red Tides, Fresh Water Verte- brates and Urban Watershed—runoff have been proposed and are in early planning stages. Contributed Papers and Posters: Both professionals and students are welcome to submit abstracts for a paper or poster in any area of science. Abstracts are required for all papers, as well as posters, and must be submitted in the format listed on the society webpage. Maximum poster size is 32 x 40 inches. In addition to the Symposia, there will be additional sessions of Invited Papers and Posters and papers by the Junior Academy members. The Poster Session will occur on Friday afternoon and early evening while invited papers will be on both Friday and Saturday. Abstracts of presented papers and posters will be published as a supplement to the August issue of the Bulletin. Student Awards: Students who elect to participate are eligible for best paper or poster awards in the following categories: ecology and evolution, molecular biology,genetics and physiology, and physical sciences. In addition the American Institute of Fishery Research Biologists will award best paper and poster in fisheries biology. A paper by any combination of student and professional co-authors will be considered eligible provided that it represents work done principally by student(s). In the case of an award to a co-authored paper, the monetary award and a sone year student membership to the Academy will be made to the first author only. For further information on posters, abstracts, registration and deadlines, see the Southern California Academy of Science web page at http://scas.jsd.claremont.edu/ outhern Calif rn ir 4) OVMITSS LAM Pet cd fwads ae oT aT te abe Civ. e , J e | i- ? LS tA \Hy) gu a oo a avibad Aaa rails Acad 1A9!, (jneagre d ad*a ts ie — > s 5 [ yiteTe wry ») MI 1A Pl reap het ry ivoh. horney ae be 4 =F ty ih. Salle, +} TAI teheosh. aie sibrsqyet je . ri hie Set wodt ot mop rT oii ii zk 30 rc) Ce ehiwG rs wy q \ » r Wen ? iar pe iret nig yt oral , 1) (7-3 wear 1 al | > rly cry ‘ ae hs c%, ' i it yt je vs I e wt liv afi ’ ie “ , » - i * ty rl ww lel i i -4 | ye tun “wl 4 oe. j iets] 00 Oe n ith! 7h Owen) Coe Soe : - if: oy? Gerrneenes oF Bull. Southern California Acad. Sci. 104(3), 2005, pp. 113-124 © Southern California Academy of Sciences, 2005 Habitat Partitioning by Three Species of Dolphins in Santa Monica Bay, California Maddalena Bearzi Department of Ecology and Evolutionary Biology, University of California, Los Angeles, 621 Circle Drive South, Box 951606, Los Angeles, CA 90095-1606, USA Phone 310-8225205, fax 310-8225729, e-mail: mbearzi@ earthlink.net Abstract.—Habitat partitioning by bottlenose dolphins (Tursiops truncatus), short- beaked common dolphins (Delphinus delphis), and long-beaked common dolphins (D. capensis), were assessed during 178 surveys conducted between 1997—2000 in Santa Monica Bay, California. Bottlhenose dolphins were found year-round with- in 0.5 km from shore in 80.0 % of the sightings (n = 137) but they were also found in deeper waters further offshore. The two common dolphin species were observed year-round (n = 83) far from shore and near escarpments; they were sympatric but never seen in mixed schools. This study suggests that habitat par- titioning in the bay probably relates to resource partitioning among three dolphins species with roughly similar ecological needs. Interspecific investigations of odontocete behavioral ecology are rare (Pola- check 1987; Selzer and Payne 1988; Shane 1994; Gowans and Whitehead 1995) and no such studies have been conducted in the Southern California Bight. Studies in Santa Monica Bay (Fig. 1; Bearzi 2005) have found that it is inhabited year- round by three relatively abundant cetaceans: the bottlenose dolphin (Tursiops truncatus), the short-beaked common dolphin (Delphinus delphis), and the long- beaked common dolphin (D. capensis). This investigation examines spatial dis- tribution and habitat partitioning of these three species in the bay between 1997— 2000. Similar species that co-occur are thought to compete for resources unless they occupy different physical locations and/or feed on different prey (Roughgarden 1976). Along the California coast, short-beaked and long-beaked common dol- phins are seldom seen close to shore, whereas populations of bottlenose dolphins occur inshore year-round (Carretta et al. 1998; Forney and Barlow 1998; Hansen 1990; Defran and Weller 1999). The genus Delphinus has been observed asso- ciated with characteristic offshore bathymetric features such as escarpments and submarine canyons (Evans 1974; Polacheck 1987; Selzer and Payne 1988; Gaskin 1992; Gowans and Whitehead 1995). This study correlates the distributions of bottlenose dolphins, short-beaked common dolphins and long-beaked common dolphins with the environmental features of Santa Monica Bay to describe habitat use and inter-specific aggregations of these species. Species Distributions The genus Tursiops is found widely in temperate and tropical waters. Popula- tions of bottlenose dolphins are known to inhabit pelagic waters as well as coastal 113 114 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES Malibu | p—_ km, LOS ge ANGELES 33°55’ Dume Canyon Santa Monica Canyon 33°50’ Redondo Canyon Palos Verdes 33°45’ Peninsula 118°50° 118°45’ 118°40° 118°35’ 118°30° 118°25’ Fig. 1. The study area and the distribution of bottlenose dolphins (X), short-beaked common dolphins (@), and long-beaked common dolphins ((_]) in the bay. Each symbol represents initial GPS coordinates of sightings. Sightings outside the bay and sightings of Delphinus spp. not recognized at the species level were excluded from this map. Submarine canyons (Dume, Santa Monica, Redondo) and escarpments/slopes (Palos Verdes continental slope, west of Los Angeles slope, south of Malibu montain slope) include respectively sightings located no farther than 0.4 km from each side of the canyons and the isobaths, and 1.8 km from the centers of the slopes. Flat areas and plateaus include all the sightings observed in these locations. Submarine canyons are indicated by the three lines. areas, including bays and tidal creeks (Leatherwood et al. 1983). These popula- tions also show morphological, osteological and molecular differentiations (LeDuc and Curry 1998; Rossbach and Herzing 1999). Coastal forms of bottlenose dol- phins exist in many areas of the world (e.g., Shark Bay, Western Australia: Connor and Smolker 1985; the Firth of Tay, Scotland: Wilson 1995; Sarasota Bay, Florida: Scott et al. 1990; Wells 1991; Argentine Bay, Argentina: Wiirsig 1978; Croatia, Mediterranean Sea: Bearzi et al. 1999). Coastal populations usually live within 0.5 km of shore in schools of 1—25 individuals, sometimes residing in a specific area, while pelagic populations are found in larger groups of 25 to several thou- sand individuals ranging widely in the open ocean (Scott and Chivers 1990; Bearzi et al. 1999; Defran and Weller 1999; Bearzi 2005). Long-term studies on free-ranging bottlenose dolphins in the Southern Califor- nia Bight have been focused mostly along the San Diego coastline (less than | km from shore; Defran and Weller 1999). In 1996, a preliminary series of cetacean surveys in the waters of Santa Monica Bay determined that bottlenose dolphins could be found there in all seasons (Bearzi 2005). Common dolphins (Delphinus spp.) also have a wide distribution in tropical and temperate waters. In the eastern North Pacific, there are two separate species of common dolphins, the short-beaked and the long-beaked common dolphin, distinguished morphometrically by Heyning and Perrin (1994) and genetically by HABITAT PARTITIONING BY DOLPHINS IS) Rosel et al. (1994). In the Southern California Bight the two species occur sym- patrically (Heyning and Perrin 1994; Rice 1998). These dolphins usually live in large schools that can reach thousands of indi- viduals (Cockcroft and Peddemors 1990; Klinowska 1991). Evans (1975) and Bruno et al. (2002), however, suggested that the basic social unit for common dolphins contains less than 30 individuals. Information on occurrence, distribu- tion, and abundance have been collected for this genus in central and southern California (Evans 1975; Dohl et al. 1986; Forney and Barlow 1998), but no information on these animals was previously available for Santa Monica Bay. Materials and Methods Study Area The Santa Monica Bay study area (approximately 460 km7’, Fig. 1) is a shallow shelf bounded by the Palos Verdes Peninsula to the South (33°45’N, 118°24'W), Point Dume to the North (33°59'N, 118°48’W) and the edge of the continental shelf to the West. The bottom habitat of the bay includes sandy soft sediments inshore and silts along slopes and canyons. This study area contains three sub- marine canyons: Dume and Redondo canyons begins in shallow water, whereas Santa Monica Canyon begins at a depth of about 100 m at the edge of the con- tinental shelf. A shallow shelf, known as “‘short bank’’, located between Santa Monica Canyon and Redondo Canyon extends as a plateau from the 50-m contour and is characterized by patchy areas of exposed bedrock, rock pinnacles, gravel, and mixed sediments (Terry et al. 1956). The mean depth of the bay is about 55 m and the maximum depth 450 m. Normal water surface temperatures range from 11 to 22°C. During the 1997-98 EI Nifo, three peaks of sea surface temperature (SST) anomalies, with an increase in temperature of +2°C, were evident in May— June 1997, September—October 1997 and August 1998 (Nezlin et al. 2003). Data Collection and Analysis Regular surveys were conducted from January 1997 to December 2000 (Table 1), with an average of 3.5 surveys per month (n = 178). Inshore and offshore surveys, defined respectively as surveys conducted at a distance from shore =0.5 km and at a distance offshore >0.5 km, were carried out from a 7-m powerboat in the morning and early afternoon. The number of kilometers surveyed in all different locations of the bay— including submarine canyons (Dume, Santa Monica, Redondo), escarpments/ slopes (Palos Verdes continental slope, west of Los Angeles slope, south of Mal- ibu montain slope), flat areas and plateaus—was calculated to determine the even- ness in the coverage of the study area using a grid comprised of 82 3.7 X 3.7 km cells (Bearzi 2003). Using Student’s t-test for independent samples, no sig- nificant difference was observed in surveying the different locations (t = 1.92, df = 28, P > 0.05). Differences in distribution among species in relation to the bathymetry of the bay were evaluated comparing their positions (initial GPS co- ordinates of dolphin sightings) among eight different isobaths from O to 600 m using a finer grid comprised of 2.5 X 2.5 km cells and calculating the total number of sightings in each cell (Bearzi 2003). Data were collected with laptop computers and occasionally with tape record- 116 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES Table 1. Number of surveys, summary of research effort, and sighting frequencies (sightings/hour) of the three most observed cetacean species in Santa Monica Bay between 1997-2000. (997, 1998 oe 2000° Total Surveys Inshore surveys 5 Ihe F2 6 40 Offshore surveys DS 3 5 4 35 Combined inshore/offshore surveys 11 38 27 2 103 Total number of surveys 39 58 44 a7 178 Research Effort Hours spent in the field 144 224 178 149 695 Hours spent searching for dolphins 110 136 130 105 481 Hours spent with the three species 26 80 53 4] 200 Hours spent with Delphinus spp. 9 L7 18 19 63 Hours spent with 7. truncatus 17 63 85 22 L3H Sightings* des) 87 SS) 47 220 Tursiops truncatus Number of sightings 19 61 33 24 137 Sighting frequency (sightings/hour) 0.13 Os Oud 0.16 0.20 Delphinus spp.** Number of sightings 10 26 24 23 83 Sighting frequency (sightings/hour) 0.07 Oz 0.14 0:15 Oo2 Delphinus capensis Number of sightings Z 13 i 10 36 Sighting frequency (sightings/hour) 0.01 0.06 0.06 0.07 0.05 Delphinus delphis Number of sightings 6 7 6 6 25 Sighting frequency (sightings/hour) 0.04 0.03 0.03 0.04 0.04 N of 5-min samples 295 1,065 698 J20) 2909 «> no data collection in Dec 1999 and Oct 2000. * one mixed school of different species is counted as one sighting. ** this calculation includes Delphinus spp. not recognized at the species level. ers. When dolphins were spotted, data on number of animals and behavior were recorded at 5-min intervals throughout the sighting (Bearzi 2003). The majority of the observations were conducted with Beaufort scale 2 or less, sea state 0 and visibility >300 m. The dolphins’ position and speed (+30 m from the boat) were approximated to the boat’s position using a GPS. The boat’s speed was reduced in the presence of dolphins and sudden speed or directional changes were avoided. To distinguish between short-beaked and long-beaked common dolphins, re- searchers took close-up photographs of the animals’ lateral foresection. Color photos were taken with 35-mm cameras equipped with 75—300-mm lenses using slide film (64-200 ISO). During the sighting, researchers also videotaped the an- imals’ lateral foresections and recorded their behavior with Hi8-mm and Mini DV Video Camcorders. Photos and videos were reviewed in laboratory for the species identification based on body features described by Heyning and Perrin (1994). A dolphin school was defined as all dolphins in continuous association with each other and within visual range of the survey team (Weller 1991). Aggregation HABITAT PARTITIONING BY DOLPHINS a referred to distances between one or more individuals of two different species being less than 100 m. Data analyses were performed using Statview 5.02 and Grapher 3.02; data on species distribution were plotted with Arcview GIS 3.2 and Surfer 6.02. Results Field Effort Data were collected during 40 inshore surveys, 35 offshore surveys, and 103 combined inshore/offshore surveys in the bay; the survey coverage between 1997 and 2000 totaled 9,526 km. A total of 446 h were spent searching for cetaceans in good weather conditions (Beaufort scale =2) and 35 h in unfavorable condi- tions (Beaufort scale >2). A total of 137 h (64.0 % of total sighting time) were spent with bottlenose dolphins during 137 sightings, lasting on average 64 min (range 3—262 min), and a total of 63 h (29.4 % of total sighting time) were spent with short-beaked and long-beaked common dolphins during 83 sightings, lasting on average 51 min (range 5—185 min; Table 1). Occurrence, Sighting Frequencies and Distribution Bottlenose dolphins were most frequently sighted year-round (62.3 % of the sightings; n = 220) generally inshore (80.0 %), followed by long-beaked and short-beaked common dolphins (respectively 16.4 % and 11.4 % of the sightings; Table 1, Fig. 2a). The two species of common dolphins were spotted only eight times (9.6 %) in inshore waters. Sightings/effort for the three species in the years 1997—2000 and during dif- ferent seasons are illustrated in Figs. 2a,b,c. Long-beaked common dolphins were Slightly more abundant than short-beaked common dolphins in the years 1998— 2000, although the difference in sighting number was not significant among the four years (long-beaked common dolphins: 59.0 %, short-beaked common dol- phins: 41.0 %, n = 61; x? = 1.33, df = 1, P > 0.05; Table 1). The distribution of the three species in relation to the bathymetry is presented in Fig. 1. Species distribution differed significantly according to depth (y? = 92.09, df = 7, P < 0.001), with bottlenose dolphins inhabiting mostly inshore waters (O—S5O m deep) and the two species of common dolphins being more frequent in deeper waters. The distribution of short-beaked common dolphins versus long- beaked common dolphins also differed significantly with depth (x? = 21.19, df = 7, P < 0.001), with short-beaked common dolphins showing a broader distribu- tion, mostly between the 50—100 m isobaths (Fig. 1). All species showed a sig- nificant preference for canyons, escarpments, and slopes (x? = 22.41, df = 5, P < 0.001). No significant difference was observed between short-beaked and long- beaked common dolphins in terms of their proximity to canyons (Dume, Santa Monica, Redondo) and escarpments/slopes (continental slope, west of Los An- geles slope, south of Malibu mountain slope; x? = 1.95, df = 5, P > 0.05; Fig. 1): Short-beaked and long-beaked common dolphins did not aggregate together, although both species aggregated with other cetaceans. In offshore waters, com- mon dolphins were observed twice in mixed schools with other cetacean species; once with Pacific white-sided dolphins (Lagenorhynchus obliquidens), and once with minke whales (Balaenoptera acutorostrata). In inshore waters, both common 118 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES 12 = 7. truncatus _|D. delphis Sightings / Effort i) CO 0.4 5 02- (pee , _S | 0 } a T ar z a i ie 2 ae’ T _i = 1997 1998 1999 2000 Years a. 0.35 - WZ truncatus (inshore) 03 4 ® T. truncatus (offshore) e 0.25 + ls a SOs = oh) = 0.14 Sb 0.05 + iM eee P3 1 a Ee ._ oo = * 4 | * mes) bis e/a|/ei2|/e1o/68/2)e/ a | cee ala |eNel ale) & eo) ame | = é a Z a = a | a a aa 2 = ZA = A | D 1997 1998 1999 2000 Years b. _|D.delphis WD. capensis = Delphinus spp. 0.14 P Pp O12 Sightings / Effort So oy &) es 5 =) WS) ES SN eo) = WINTER fa a FALL fal WINTER* fe nt FALL See | a al pee x|\o|el2i8/¢/8 2/e@iale| 2 levee See aceias ae 2 | & 5 | 2 cele & a, = A. = ue |e | & a a = 72) 5 “a 5 AMS | = A) | > YN Nn N Nn | 1997 1998 1999 2000 Years e Fig. 2a,b,c. (a) Sightings/effort for the three species observed in the bay during the years 1997— 2000, (b) sightings/effort for 7. truncatus observed during inshore and offshore surveys and, (c) sightings/effort for D. capensis, D. delphis, and Delphinus spp. (animals recognized only at genus level). In figures 2b,c, the years were divided into four seasonal categories: Winter (December—Feb- ruary), Spring (March—May), Summer (June-August), and Fall (September—November). No data was collected in December 1999* and October 2000*. HABITAT PARTITIONING BY DOLPHINS 9 dolphin species were observed 87.5 % of the sightings (n = 7) in mixed schools with coastal bottlenose dolphins. Discussion Bottlenose dolphins were most often observed in Santa Monica Bay, generally sighted within 0.5 km of shore, as is the case along the San Diego coastline (Defran and Weller 1999). The occurrence of Delphinus spp. in Santa Monica Bay was also consistent with reports for other areas of the California coast (South- ern California Bight: Norris and Prescott 1961; Leatherwood et al. 1988; Bonnell and Dailey 1993; California coast: Forney and Barlow 1998). In the bay, both species of common dolphins were sighted year-round and mostly offshore with similar distributions. Long-term studies on inshore bottlenose dolphins suggest that their distribution may be related to the distribution and abundance of nearshore prey (Defran and Weller 1999). Stomach content show that 74.0 % of their prey were either surf- perches (Embiotocidae) or croakers (Scianidae) (Norris and Prescott 1961; Walker 1981; Hanson and Defran 1993). These prey species occur year-round in shallow coastal waters of the Southern California Bight (Cross and Allen 1993). The year- round abundance of bottlenose dolphins in Santa Monica Bay may be explained by a year-round presence of nearshore prey (Deets and Roney 1999; California Department of Fish and Game 2000; Bearzi 2005). The more-offshore sightings of short-beaked and long-beaked common dol- phins may be related to different prey preferences (Table 2). For short-beaked common dolphins, Evans (1975) found their main prey in the Bight was anchovies (Engraulis mordax) whereas Fitch and Brownell (1968) and Schwartz et al. (1992) reported that squid (family Gonatidae and Loligo opalescens) and Pacific whiting (Merluccius productus) were their primary prey. All these prey species are pri- marily pelagic inhabitants of the Bight (California Department of Fish and Game 2000). In Santa Monica Bay, therefore, inshore bottlenose dolphins and the two species of common dolphins differ both in distribution and prey preference. I suggest that the habitat partitioning of these species is a consequence of prey specialization and competition for resources in inshore waters. The three species distributions did overlap, however near Redondo Canyon and the continental slope south of Palos Verdes Peninsula (Fig. 1); these areas are the deepest and steepest features in the bay (Dartnell and Gardner 2004). Upwelling of highly oxygenated and nutrient-rich water was found over the San Pedro shelf and eddy-like features near the slopes in the southern half of Santa Monica shelf were also observed (Hickey 1992, 1993). These oceanographic features are op- timal for mixing of nutrients that would provide rich feeding grounds for dolphins. Anchovies are known to concentrate in submarine canyons and escarpments in areas of upwelling (Mais 1974; Hui 1979). This potential abundance of prey was likely to allow the three species to coexist in the same areas. Other locations of the bay near canyons, escarpments and slopes show a sig- nificantly higher number of sightings than flat areas and plateaus. These results show interesting parallels with white-sided dolphins (Lagenorhynchus acutus) and short-beaked common dolphins along the continental shelf of northeastern United States (Selzer and Payne 1988), and various odontocetes near a submarine canyon on the Scotian Shelf (Gowans and Whitehead 1995). Other authors have also 120 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES Table 2. Diet of 7. truncatus and Delphinus spp. in Southern California waters. N = nearshore prey, O = offshore prey, B = prey present in both, inshore and offshore waters (e.g., different seasons, different life stages, etc.). Prey Habitat T. truncatus! Delphinus spp.’ Walleye surfperch (Hyperprosopon argenteum) Pile surfperch (Damalichthys vacca) Black surfperch (Embiotoca jacksoni) Shiner surfperch (Cymatogaster aggregatus) White surfperch (Phanerodon furcatus) Barred surfperch (Amphistichus argenteus) Blacksmith (Chromis punctipinnis) Spotfin croaker (Rancador stearnsi) Kelp bass (Paralabrax clathratus) Smelts (Osmeridae) Queenfish (Seriphus politus) California halibut (Paralichthys californicus) Yellowfin croaker (Umbrina rancador) White croaker (Genyonemus lineatus) California corbina (Menticirrhus undulates) Specklefin midshipman (Porychthys myriaster) Octopoteuthidae Plainfin midshipman (Porychthys notatus) Cusk eel (Ophidiidae) Jack mackerel (Trachurus symmetricus) Northern anchovy (Engrualis mordax) Market squid (Loligo opalescens) Sardine (Sardinops coerulea) Pacific mackerel (Scomber japonicus) Pacific whiting (Merluccius productus) Northern lampfish (Stenobrachius leucopsarus) Bonito (Sarda chiliensis) California Smoothtongue (Bathylagus stilbius) Pacific pompano (Peprilus simillimus) Lanternfish (Myctophidae) Medusafish Ucichthys lockingtoni) Onychoteuthidae Gonatus sp. Km mK mK KK MK KM KK KK MK KM ~*~ COCCOOCOCOOCWAWPWCWWDAABDAWBWADEAZAZAZAZLZAZLZZAZAZLZZY KKK mM KM KK MMM KKM ' Walker 1981; Hanson and Defran 1993 (for coastal populations). Data from stomach contents. > Norris and Prescott 1961; Fitch and Brownell 1968; Evans 1975; Schwartz et al. 1992; Bonnell and Dailey 1993; M. Bearzi pers. obs. Data from stomach contents and fish scale collection. reported the presence of the genus Delphinus along sea floor reliefs, submarine canyons and escarpments (Evans 1974; Hui 1979; Polacheck 1987; Selzer and Payne 1988; Gaskin 1992; Gowans and Whitehead 1995), showing that undersea topography, rather than water depth, is the most significant physical feature influ- encing the distribution of common dolphins. In Santa Monica Bay, the two species of common dolphins have the same preference for the same escarpments, slopes and submarine canyons, but short- beaked common dolphins show a less-defined distribution, predominantly between the 50—100 m isobaths. The year-round co-occurrence of these species in the study area over four years may be related to productive feeding grounds, rich enough in prey to support their feeding requirements. This is suggested by the relatively high amount of time spent feeding or diving (about 30.0 % of total time; Bearzi HABITAT PARTITIONING BY DOLPHINS 121 2003) in comparison to data reported by Neumann (2001) for the Bay of Plenty, New Zealand (17.0 % of total time). Shifts in abundance of long-beaked and short-beaked common dolphins were observed since the last century in southern California waters (Banks and Brownell 1969; Heyning and Perrin 1994). In this study, long-beaked common dolphins were the more common in the bay starting from 1998, at the end of the 1997— 1998 El Nino, showing a pattern similar to the one previously observed by Heyn- ing and Perrin (1994). These authors suggested that environmental factors may be more advantageous to one or the other species at different times. However, differences in habitat use between short-beaked and long-beaked common dol- phins are complex, considering the similar diet of the two species (Fitch and Brownell 1968; Schwartz et al. 1992; Ohizumi 1998). In the southern California waters, stomach content analyses showed that short-beaked common dolphins feed more on squid, a prey usually caught at depth during the day or at surface at night, than do long-beaked common dolphins (Schwartz et al. 1992). Decreased squid abundance during the last two El Nifio events (California Department of Fish and Game 2000) could partially explain the greater number of short-beaked common dolphins before both El Nino events and the decrease in number after these events. Although short-beaked and long-beaked common dolphins were both sighted in similar locations of the bay, confirming a sympatric micro-range, no occurrence of these two taxonomically close species in mixed schools was ever observed. The slight difference in diet could indicate a separation of ecological niches re- ducing the occurrence of direct competition for food resources when the dolphins are sympatric. Different preferences in prey for sympatric dolphins were observed by other authors (Das et al. 2000; Hale et al. 2000). Gowans and Whitehead (1995) explained the co-occurrence of species either by a superabundance of food or by a slightly different diet that may eliminate a competitive pressure between the species. Conclusions Spatial habitat partitioning by different dolphin species has rarely been de- scribed in detail (Selzer and Payne 1988; Gowans and Whitehead 1995). This study provides a description of habitat partitioning by three species of dolphins in Santa Monica Bay. Bottlenose dolphins were found year-round in shallow wa- ters, clearly separated from the distribution of short-beaked and long-beaked com- mon dolphins, but they were also observed occasionally in deeper waters over the continental shelf and pelagic waters outside the bay. Short-beaked and long- beaked common dolphins were found year-round in the bay but mostly far from shore. Both common dolphin species were sighted in areas of complex underwater topography. Although they were observed in similar locations of the bay, con- firming their sympatric range, these two species were never seen in mixed schools. Acknowledgments The manuscript was improved through review by W. Hamner, J. Heyning, G. Grether, and B. Schlinger. I also wish to express my gratitude to G. Bearzi, N. Nezlin, S. Strand, A. Azzelino, and P Mendel. The field research was funded by Ocean Conservation Society, The UCLA Mentor Research Program Fellowship 122 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES and The Coastal Environmental Quality Initiative Fellowship. This study would not have been possible without the help of C. Saylan and the Los Angeles Dolphin Project assistants and volunteers. Special thanks also to Maptech, Trimble Navi- gation, and ESRI. Field work was carried out under the current laws of California and the General Authorization for Scientific Research issued by NOAA (File No. 856-1366). Literature Cited Banks, R.C. and R.L. Brownell. 1969. Taxonomy of the common dolphins of the eastern Pacific Ocean. J. Mammal., 50:262—272. Bearzi, M. 2003. Behavioral ecology of the marine mammals of Santa Monica Bay, California. Ph.D. dissertation, University of California, Los Angeles, CA. 239 pp. Bearzi, M. 2005. Aspects of the ecology and behaviour of bottlenose dolphins (7ursiops truncatus) in Santa Monica Bay, California. 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The ecology of bottlenose dolphins on the Moray Firth, Scotland: a population at the Northern extreme of the species’ range. Ph.D. dissertation, University of Aberdeen, Scot- land. 191pp. Wirsig, B. 1978. Occurrence and group organization of Atlantic bottlenose porpoises (7ursiops trun- catus) in an Argentine bay. Biol. Bull., 154:348—359. Accepted for publication 16 March 2005. Bull. Southern California Acad. Sci. 104(3), 2005, pp. 125-145 © Southern California Academy of Sciences, 2005 Dry-season Water Quality in the San Gabriel River Watershed Drew Ackerman, Eric D. Stein, and Kenneth Schiff Southern California Coastal Water Research Project, 7171 Fenwick Lane, Westminster, California 92683 Abstract.—Dry-season flow in the San Gabriel River system is comprised mostly of discharges from water reclamation plants (WRPs), imported water, and storm drains. Although the magnitude of dry-season discharge is generally known, the water quality associated with most of these “‘introduced”’ discharges has not been characterized, nor has the associated in-stream response, particularly near storm drain discharges. The goal of this study was to characterize the pattern and mag- nitude of storm drain and WRP inputs to the San Gabriel River system and the associated in-stream response. To accomplish this, two synoptic dry-weather sur- veys were conducted, one in 2002 and the other in 2003 during which flow, metals, bacteria, and nutrient concentrations were measured from the WRPs, storm drains, and in-stream locations at a single point in time. For bacteria and most metals, storm drains accounted for the majority of mass emissions to the river. In contrast, WRPs were the primary source for nutrients. In-stream water quality concentrations generally reflected the main sources. For example, in-stream am- monia concentrations were highest downstream of WRP discharges. In-stream bacteria concentrations were consistently high and showed no apparent spatial pattern, suggesting that storm drains or other in-stream sources are present throughout the watershed. Urbanization has had many consequences on the hydrology of southern Cali- fornia’s coastal watersheds (Hamilton 1992; Schuler and Holland 2000; Roesner and Bledsoe 2003). Streams historically convey seasonal storm flows and are dry for large portions of the year. Today, large engineered channels have replaced most large streams and rivers to accommodate increases in storm water runoff. In: addition, the historical intermittent hydroperiod has been replaced by year- round baseflow. In the San Gabriel watershed, the large engineered channels that predominate in the lower watershed receive dry-weather flow from a variety of “introduced” sources, such as water reclamation plant (WRP) discharges, other National Pol- lutant Discharge Elimination System (NPDES) discharges, storm drain discharges of non-point source runoff from the developed landscape, and imported water that is conveyed seasonally through the San Gabriel River and its tributaries to spread- ing grounds located throughout the watershed. Dry-season sources of water may include a suite of urban-generated constitu- ents that have the potential to affect surface water quality adversely. For example, storm drains have been found to be the primary source of pollutants in the neigh- boring Los Angeles River watershed (Ackerman et al. 2003). Also, Bay et al. (1996) found that dry-weather runoff to the Santa Monica Bay contained toxic levels of certain constituents. Previously, documented concentrations of nutrients, as) 126 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES metals, and bacteria have resulted in large portions of the lower San Gabriel watershed being listed as impaired under Section 303(d) of the Clean Water Act. Managing dry-season water quality requires an understanding of the water qual- ity associated with the primary sources of dry-weather flow (1.e., storm drains and WRP discharges), and the relationship between these sources and in-stream water quality. Although hundreds of storm drains discharge to the 303(d) listed portions of the San Gabriel River and its tributaries, the spatial and temporal patterns of these inputs relative to those of the WRPs have not been quantified. Furthermore, the relative mass contribution of pollutants from storm drains and WRP discharges has not been investigated, nor has the response of in-stream water quality to these mass loadings. The goal of this study is to characterize storm drain and WRP inputs to the San Gabriel River system and the associated in-stream response. The relative contribution of non-point source (1.e., storm drain) and point source (1.e., WRP) inputs were quantified for bacteria, metals, and nutrients. The observed concen- trations also were compared to existing water quality standards in order to provide managers with information that can be used in developing strategies to address water quality impairments. Methods This study is comprised of two parts. The first part consists of identifying and sampling the major inputs to the San Gabriel River and its major tributaries. The second part is comprised of sampling the in-stream water quality to assess spatial water quality patterns and the relationship between sources and in-stream water quality. Two synoptic surveys were conducted approximately one year apart dur- ing which approximately 85 storm drains and 16 in-river sites were sampled twice over a 2-day period each year. Watershed The 1,866 km? San Gabriel River (SGR) watershed (Figure 1) is highly urban- ized in its lower portions, and predominantly undeveloped in the upper watershed. The reaches that are listed as having impaired water quality and are the focus of this study are San Gabriel River, Coyote Creek (CC), San Jose Creek (SJC), and Walnut Creek (WC) (Table 1). Any storm drains, channels, or other discharges to these reaches were considered inputs to the system. Flow through the SGR system is highly managed by diversions and concrete and rubber dams that route water to various infiltration areas. As a result, dry- weather flows are highly variable both within and between years (_LACDPW 2004). For example, in Water Year (WY) 2002-03, the Los Angeles County Department of Public Works (LACDPW) imported 1.02 x 10° m?* of water (LACDPW 2004) and conveyed much of that water through the SJC and WC systems to spreading grounds. In that same year, 7.01 xX 10° m?* of water from the San Jose Creek and Pomona WRPs was sent to spreading grounds, while 1.40 x 10’ m? was allowed to pass to the ocean (LACDPW 2004). The earthen bottom portions of the SGR are used for infiltration; therefore, although physically con- nected, the WC and SJC are often hydrologically discontinuous from the SGR during dry-weather conditions (Figure 2). SAN GABRIEL RIVER WATER QUALITY 27 oe | + creek wainut dy OO Pp x Bas is la omona } > PAS SanJose / San Jose San Jose mies Creek ie eae eee West WRP East WRP < re oad © Input Sampling Sites A In-river Sampling Sites A Water Reclamation Plants Gal irestone Discharge ee a pe' Los Coyotes j eee =) RP ino |] < 9 eos _ Los Angeles” i) Beach WRP Kilometers Fig. 1. Map of the San Gabriel River watershed. Shown are the impaired streams, storm drain locations during the two surveys, in-stream sampling points, stream gages and water reclamation plant discharge locations. Input Sampling Inputs to the SGR watershed were sampled on September 29, 2002 and Sep- tember 14, 2003. Point source inputs included four WRPs that discharge tertiary treated wastewater. The Los Coyotes WRP discharges to the SGR, the Long Beach WRP discharges to the CC, and the Pomona WRP discharges to the SJC. The San Jose Creek WRP discharges to both the SJC and SGR. The WRP effluent was collected as a 4-hour composite sample and analyzed for the parameters listed in Table 2. Inputs that convey non-point source discharge were sampled synoptically dur- ing each of the two sampling events. Non-point source inputs were classified as either “‘small storm drain” discharges or “‘large NPS” discharges. The latter con- sisted mainly of open channels that drain to the impaired reaches that are the focus of this study (Table 3). Prior to each sampling event, storm drains and large NPSs were surveyed to identify those that flow during the dry season. At each flowing storm drain or large NPS, flow was measured using either timed-volu- metric or depth-velocity methods (as appropriate, given the conditions at the lo- cation). Water quality samples were collected directly by filling the sample bottle or using a sterilized scoop to collect the water sample. Samples were placed on ice and transported to the laboratories for analysis of the parameters listed in Table 1. San Gabriel River Coyote Creek San Jose Creek Walnut Creek Length 4] 21 52 19 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES (km) List of stream impairments and their lengths for the San Gabriel Watershed. Impairment Algae, coliform, dissolved copper, lead, dissolved zinc, toxicity, abnormal fish histology Algae, coliform, dissolved copper, dis- solved lead, total selenium, dissolved zinc, toxicity, abnormal fish histology Algae, coliform Toxicity, pH San Jose Creek at 7th Avenue A) 9/29/2002 . 9/30/2002 0.020 + “yw 0.015 4 = & 0.010 4 LL 0.005 0.000 7 T T t T T T 0:00 6:00 12:00 18:00 0:00 6:00 12:00 18:00 0:00 San Gabriel River above Spring St 8 C) 9/29/2002 9/30/2002 "yy E = © LE 1 +—— — — 0:00 6:00 12:00 18:00 0:00 6:00 12:00 18:00 0:00 Walnut Creek at Puente 0.025 Big. 2: 0.5 9/30/2002 9/29/2002 ; T T T T T T si! 0.4 0:00 6:00 12:00 18:00 0:00 6:00 12:00 18:00 0:00 Coyote Creek at Spring St 0.8 4 9/29/2002 9/30/2002 0.6 + 1 1 1 t 1 1 r | 0:00 6:00 12:00 18:00 0:00 6:00 12:00 18:00 0:00 In-stream flow variability for the 2002 sampling survey by stream. SAN GABRIEL RIVER WATER QUALITY 129 Table 2. Constituents sampled during each survey along with the analytical method used and the reporting limit. Analytical Method Reporting Limit Bacteria Enterococcus Quanti-Tray 10 MPN/100mL E Coli Quanti-Tray (2003) 10 MPN/100mL Fecal Coliform Membrane Filtration (2002) 10 MPN/100mL Total Coliform Quanti-Tray 10 MPN/100mL Generals Hardness EPA 130.2 - titration 2 mg/L pH EPA 150.1 N/A TSS EPA 160.2 - GF/C filtration 2 mg/L Metals Aluminum EPA 200.7 - ICP/AES 50 ug/L Arsenic SM 3114 B4d - hydride generation 1 ug/L Cadmium EPA 213.2 - Stabilized temperature 0.4 ug/L platform furnace Chromium EPA 200.7 - ICP/AES 10 ug/L Copper EPA 200.7 - ICP/AES 8 ug/L Iron EPA 200.7 - ICP/AES 50 ug/L Lead EPA 239.2 - Stabilized temperature 2 ug/L platform furnace Nickel EPA 200.7 - ICP/AES 20 ug/L Selenium SM 3114 B - hydride generation 1 ug/L Zinc EPA 200.7 - ICP/AES 10 ug/L Nutrients Ammonia SM 4500 NHGBE - titrimetric distil- 100 ug/L lation Nitrate-Nitrite EPA300.0/SM 4500NO2 B - ion 50 ug/L chromotography TKN SM 4500 NorgB - organic N diges- 100 ug/L tion + titrimetric distillation Dissolved Phosphorus EPA 365.3 - spectrophotometric 50 ug/L Total Phosphorus EPA 365.3 - spectrophotometric 50 ug/L Pesticides Diazinon ELISA 0.05 ug/L Table 2. The analytical methods and reporting limits for each constituent are listed imetable 2. In-stream Sampling The day after the storm drain sampling (September 30, 2002 and September 15, 2003), in-stream water quality samples were taken from each of the four study streams. Samples were taken at the upstream boundary of each reach, at the most downstream point, and at points between to characterize water quality changes (14 locations in total) (Figure 1). Six additional sites were added in 2003 to better resolve longitudinal in-stream water quality. Composite samples were collected by taking three grab samples over a 10-min period. A second composite sample was collected 20 min later, and a third composite was collected 40 min after the initial composite. The three samples were analyzed separately to characterize the short-term in-stream variability. Flow information was obtained from existing flow gages maintained by the Los Angeles County Department of Public Works. Data Analysis Flow and water quality data were analyzed for spatial and temporal patterns. Means and ranges of flow and concentration for all locations were analyzed by 130 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES Table 3. Large non-point source (NPS) discharges to the impaired reaches of the San Gabriel River Watershed. Receiving Water Reach Large NPS Discharge Coyote Creek Carbon Creek Brea Creek Fullerton Creek La Mirada Wash San Jose Creek Lemon Creek Diamond Bar Wash Puente Creek Walnut Creek Big Dalton Wash (includes San Dimas and Little Dalton Wash) individual sampling date and compared between sampling dates. Constituent loads were calculated by multiplying flow times concentration for each sample, as de- scribed in Schiff (1997): Load = » EC, where F, was the flow and C,; was the constituent concentration at location 1. When multiple samples were averaged, results are presented as means + the 95% confidence interval. In all cases, nondetectable results were assigned a value of zero. Results One hundred storm drains and eight large NPS discharges were sampled over the two sampling periods. During the 2002 survey, 87 storm drains were sampled and the majority of those storm drains were in the SJC (Table 4). In 2003, 84 storm drains were sampled, with 58 of those drains being the same as the ones sampled in 2002. The same 6 large NPS discharges were sampled in both 2002 and 2003. Table 4. Measured flows (10° L d~') and number of samples by stream reach and source category. Coyote San Gabriel San Jose Walnut Total Flow 10° L Flow 10° L Flow 10° L Flow 10° L Flow 10° L 2002 ds} N d=! n dy N az n dr n Storm Drains 26.0 YS) 45 19 35:0 32 3.0 9 71.4 DD Large NPS 20.3 4 -- 0) DS l 14.7 | 37.4 6 WRPs 0.1 l 238.5 2 142.7 3 -— 0 381.2 6 LOTAL 46.3 20 246.0 pA 180.1 36 77 10 490.1 87 Coyote San Gabriel San Jose Walnut Total Flow 10° L Flow 10° L Flow 10° L Flow 10° L Flow 10° L 2003 dF n di N dz} N diy! n as} n Storm Drains 29.0 16 3.9 10 330 33 4.2 13 70.1 re? Large NPS 18.2 4 _ 0 16.3 | 9.6 l 44.0 6 WRPs 45.8 | 255.5 2 DINERS) 3 — 0 514.8 6 TOTAL 93.0 21 259.4 12 259.4 3] 13.8 14 629.0 84 SAN GABRIEL RIVER WATER QUALITY 131 100 % A) CC storm drains —_—_—_ SGR storm drains —------— SJC storm drains 80 % —-— —:- WCstorm drains All Storm Drains > 60% (= oO 5 Or ri) i «040% 20 % 0% —— rr —rerret rp 104 10° 102 10° 108 10' 10 10° Flow (L sec) 100 % B) — 2002 flow 2003 flow 80 % ao 60% = ) =) tor co) tL 40 % 20 % 0% = at} ae iis ae 9 = ttt > 1} a) roy raraet T, Toll 107 13 10 10" 108 10! 102 10° Flow (L sec’) Fig. 3. Distribution of observed storm drain flows by sampled stream (A) and by survey for all flowing storm drains sampled in the SGR watershed (B). Flow Nearly 80% of measured flow in the SGR watershed was from the WRPs during both surveys (Table 4). The majority originated from the San Jose Creek WRP, and discharged either to the confluence of San Jose Creek and San Gabriel River or through a pipeline that discharged to the San Gabriel River 16 km downstream of the confluence. Over 80% of the storm drains and large NPS discharges carried flows less than 28 L s“! (1 cfs) (Figure 3). Flows over 5 L s~! comprised the top 30% of the flowing drains and were comparable between the two surveys. Higher proportions of storm drains had small flows (i.e., below 5 L s~') in 2002 as compared to 2003. These differences at storm drains with very low flow may be due to true interannual variability, but could also be an artifact of the inherent SOUTHERN CALIFORNIA ACADEMY OF SCIENCES N (99) SosIVYOSIG SqN 2310] SUIRIG, WI01S LEO CLO 90'°0 80°0 O10 a0) S00 ysu d-ajeydsoyd [vol Cre Ip'6 €S'0 79'T Len OI ZO0'0 Tysu NOLL 9G 1 00'¢€ tS'0 6+'0 Ce] OC'€ OKO) Tysu SIIN-O1.01N 1O'€ 10°8 LO'0 S00 Lv'0 VL 10°0 Tsu N-vruowUry SJUSLONN 6£'8 O'Sr OGG Ge L€8 pel Ol TVsn UIT, — GG 000°09F*7 000°0Z0'I 000°86I OO00'LLI Ol TU001/NdN SULIOFIJOD [PIOL ZL‘0 970 00S*07 066°7 067 I OIT I Ol TUOOI/NdN SUIOJIJOD [B94 a= CN OOr'SS OO 67 OOE'SI 009°LI Ol TH001/NdIN SNIIOIOAAUA BLIOJOR TO %S6 ISLIOAY TO %S6 ISCIOAY TO %S6 ISCIOAY TaW synsay TOOT ‘POINSBdU SEM 1/09 “A €OOT UL SROIOYM ‘POINSRVOU IDIOM SULIOJITOD [B994 ZOOT Ul IY) VION “O19zZ 9q 0} pouNsse aioM saTduuKs s[qeIddNOPUON ‘sJUENINsSUOS JOYIO [[e JOF payodar are SURO ONeUIY Ie ‘saydures eLiaj}OKq JO} poyiodal aie SURdUT SINOUIOSH “adInNOs Aq [BAIDU IDUIPYUOS JUDIIEd CGH PUL SUOTJRNUSIUOD PadAtasqo Jo uvIIY “C¢ FGUL (oe) loa) SAN GABRIEL RIVER WATER QUALITY JTQuRIIeAR vIeEP ON 910 ero 9r'0 COT EL'0 O0'€ ce0 Obl 80°L GL = CN = CN O9€ P89 == CIN =, CN 681 061 a CN 60'S £60 = CN TO %S6 IBVIOAV SduM TO %S6 CN CN 006 6C 080°6 099"| ISVIDAY sosieyosiq SdN 201k] OO IC OLO'6 89 WO) YO) O08 IC OO Ol OS9 ISVIOAY sUTeIq, WHOS ‘ponunuoy “¢ a1gRL TCW TVsn Tsu “TWOOT/NdW “TWOOT/NdW [M00 1/NdW UOUIZPIG, d-areydsoyud [P10], NOLL SIN -9}8-DIN N-PruowuUly SJUSL.NNN OUIZ, [S19IN pes] uOd] jladdog uInIuUO1YyD ssoupieH s[RIa SULIOJIJOD [PIOL TOS “A SNIOIOAIJUT BIIOJOV | synsoy COOC 134 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES variability associated with measuring storm drain flows, which increases dramat- ically in drains with low discharge. Water Quality The mean concentration of water quality constituents varied by source (Table 5). The WRPs had the highest nutrient concentrations (e.g. 3.0 mg/L of nitrate- nitrite vs. 0.03 mg/L for storm drains). Storm drains and large NPS discharges had the highest bacteria concentrations (e.g. 10*-10° MPN/100 ml of total coli- forms vs. <10' MPN/l00ml for WRPs). Metal concentrations were generally higher in the storm drain and large NPS discharges than from WRPs, but there were some differences based on individual metals. In general, metals concentra- tions were lower in large NPS discharge tributaries than in small storm drains. Concentrations and loads from WRP and non-point source inputs generally were higher in 2002 than in 2003. For example, total coliform concentrations from storm drains and large NPS discharges were between 10 and 30 times higher in 2002 than in 2003, while loads were between 9 and 50 times higher in 2002 (Figure 4). Similarly, fecal coliform loads in 2002 were up to 40 times higher than E. coli loads in 2003. Assuming fecal coliforms are comprised of approxi- mately 80% E. coli, the loads would still have been more than 30% higher in 2002 than in 2003. Metals concentrations were also higher in 2002 (with the exception of zinc), but were typically within the same order of magnitude during both surveys. Overall, daily loads of copper were 2 times higher in 2002 than in 2003; however, in 2002 small storm drains accounted for a substantially lower proportion of copper relative to large NPS discharges than in 2003 (Figure 4). Bacteria and metals data were approximately the same for the WRPs between the two surveys. However, nutrient concentrations were generally 50% lower during the 2003 survey, due to operational changes at the WRPs. Source Comparison to Standards Water quality from the storm drains frequently exceeded water quality standards for bacteria. The bacteria levels observed in storm drain flows (Figure 5) exceeded water quality standards in 98% of the sampled drains. In contrast, in-river metals concentrations never exceeded the hardness-adjusted acute water quality standards under the California Toxics Rule (CTR; Figure 6). Although the CTR generally applies only to receiving waters and not to storm drain or NPS discharges, such a comparison is instructive for identifying potentially problematic discharges. In general, storm drain and large NPS discharges were also below CTR standards, except for copper, which exceeded acute CTR standards in 4% to 8% of the storm drain and large NPS inputs; and zinc, which exceeded chronic CTR standards in 2% to 8% of the storm drain and large NPS inputs (Figures 5 and 6, Table 6). Mass Emission The major pollutant sources to the SGR watershed differed by constituent (Ta- ble 7). The WRPs contributed approximately 90% or more of the nutrient mass loadings to the system. In contrast, almost all bacteria loading was contributed by storm drains and large NPS discharges. In 2002, the eight large NPS discharges accounted for over twice as much bacteria load to the system as the small storm drains, despite having less flow. In contrast, in 2003, the bacteria load from large SAN GABRIEL RIVER WATER QUALITY 135 Mme storm drains large HPS discharges Macnitude Change 2002 vs 2003 *-fold organism siday ss = Fecal Coliform Enterococcus Total Coliform Bs =torm draire large NPS de charges ee WR P #- fold kg/day Magnitude Change 2002 vs 2003 Copper lron Lead Mickel Zinc Fig. 4. Comparison of daily loads between 2002 and 2003 for bacteria (top) and metals (bottom). Values are in magnitude difference. Bars below the line indicate higher loads in 2002; bars above the line indicate higher loads in 2003. 136 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES 100 % B) 100 % 80% + 80% 4 > 60% 4 oS 60% - = (= © ) >) =) (on (on ® © ic 40% - um 40% 5 20% + 20% + 0% 0% 0 2 4 6 cy ge) Aaah IS QO 20 40 60 80 100 120 140 160 180 200 Ammonia (mg/L) Total Copper (ug/L) 100 % 100 % 2 is] zo} Cc Ay 80% 4 Ss 80% E £ ro} oS 60% - 2 > 60% - S © S y : g oy = on oO c<) ic 40% - ic 440% 20 % 270% - = | — 2002 Fecal coliforms — = 2003/En Coll 10° 10! 10° 10° 10 10 10° 10’ 0 200 400 600 800 1000 Bacteria (MPN/100 mL) Hardness (mg/L) Fig. 5. Distribution of observed storm drain water quality concentrations by year. NPS discharges was lower than that from small storm drains. The relative mass emission of trace metals varied by source and by metal. In 2002, the large NPS discharges accounted for twice as much copper, iron, and lead relative to the small storm drains; in 2003, copper and iron emissions were higher in small storm drains than in the large NPS discharges. In both years, loadings of copper, lead, and nickel from the WRPs was minimal; however, the WRPs contributed the majority of zinc loading and between 12% and 51% of lead loading. Coyote Creek and the San Gabriel/San Jose Creek confluence area received the greatest mass loadings of pollutants of the four streams (Table 8). The large bacteria loading to Coyote Creek reflected the large storm drain volumetric inputs (Table 4). Large nutrient loadings in the SJC corresponded to large volumetric discharges from the San Jose WRP (214 X 10° L d™! in 2002). Walnut Creek received no WRP input and had volumetric loadings less than half of the CC and SJC. Despite its low flow relative to other portions of the system, bacteria loadings SAN GABRIEL RIVER WATER QUALITY 200 137 A) Acute Standard ——— Chronic Standard e) Large Storm Drain i) A VRP a) Instream oy O Storm Drain © oO a 100 + S oe Toi re) | oO Kk 0 Hardness (mg/L) 200 ee 100 Total Copper (ug/L) Hardness (mg/L) Acute Standard Chronic Standard Large Storm Drain WRP Instream Storm Drain Fig. 6. Measured hardness-dependent copper toxicity by source and year. Table 6. Percent of all samples (.e., storm drains, large non-point source inputs, and WRP dis- charges) that exceeded the hardness-adjusted acute and chronic California Toxics Rule (CTR) metals criteria by year. Acute Criteria 2002 Cadmium 1% Chromium 0% Copper 5% Lead O% Nickel 0% Silver 0% ZING 5% 2003 O% O% 2% O% O% O% 1% Chronic Criteria 2002 2003 1% O% O% 0% 10% 71% 2% 3% O% O% O% O% 5% 1% 138 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES Table 7. Total mass emission by source for the two dry-weather sampling events. Samples with non-detectable values are treated as zero. Percent Contribution Total Mass Storm Large NPS Consituent Emissions Units Drains Discharges WRPs 2002 Bacteria Fecal Coliforms 1,800 (0?) hr=! 34% 66% O% Enterococcus 948 (10?) hr~ 35% 65% O% Total Coliforms 48,300 GO?) hes! 28% 72% O% Metals Copper 0.0285 kg hr! 38% 62% 0% Iron 7.94 keohre 30% 58% 12% Lead 0.0083 kg hr 29% 71% 0% Nickel 0.0023 kee hry! 100% 0% O% Zinc 0.79 kg hr! 14% 8% 78% Nutrients Ammonia-N 87.6 kg hr! 1% O% 99% Nitrate-Nitrite 69.1 kg hr=! 5% 1% 94% TKN 113 Kee lites 3% 2% 95% Total Phosphorous 7.67 ke hrs’ 8% 1% 90% 2003 Bacteria E. coli 800 (10°) hr-! 91% 9% O% Enterococcus 1,110 (10°) hr7! 58% 42% O% Total Coliforms 2,090 CO?) hes 68% 32% 0% Metals Copper 0.014 kg hr=! 100% O% O% Iron PLR) | kg hr! 33% 16% 51% Lead 0.0060 kee Tare? 25% 715% 0% Nickel 0.0003 ke: hires! 100% 0% 0% Zinc 1.74 ke hr 11% 71% 82% Nutrients Ammonia-N 26.6 kg hr'! 1% O% 99% Nitrate-Nitrite 66.6 kg hr'! 8% 2% 90% TKN 57.9 ke bry 71% 3% 89% Total Phosphorous WMS) kg hr“! 6% 4% 89% from Walnut Creek in 2003 nearly equaled those in the CC and SJC. High load- ings in WC are attributed mainly to high in-stream concentrations, which are more than 200% higher than those of the other streams. In-stream Concentrations The spatial distribution of pollutants throughout the four reaches in the SGR watershed reflects the influence of major mass emission sources (Figures 7—9). For nutrients, in-stream ammonia levels in the SJC and the SGR were markedly higher downstream of the Pomona, San Jose Creek, and Los Coyotes WRPs (Figure 7). Where storm drains were the only inputs; i.e., upper Coyote Creek and Walnut SAN GABRIEL RIVER WATER QUALITY 139 Table 8. Total mass emission by creek for the two dry-weather sampling events. Percent Contribution Total Mass Coyote San Gabriel San Jose Walnut Consituent Emissions Units Creek River Creek Creek 2002 Bacteria Fecal Coliforms 1,800 (10°) hr=! 66% 5% 17% 12% Enterococcus 948 C07) hr 62% 20% 10% 1% Total Coliforms 48,300 @O@2) hr: 62% 14% 16% 8% Metals Copper 0.0285 kg hr=! 22% 12% 20% 46% Iron 7.94 ke ir 58% 9% 31% 2% Lead 0.0083 kee ire 55% 14% 8% 24% Nickel 0.0023 ke bre! 9% 50% 36% O% Zinc 0.79 kg hr=! 8% 53% 36% 3% Nutrients Ammonia-N 87.6 kg hr! 0% 55% 45% 0% Nitrate-Nitrite oon ke hr 2% 67% 31% 0% TKN 113 kg hr“! 2% 55% 42% 1% Total Phosphorous W677 kg hr7! 5% 54% 41% O% 2003 Bacteria E. coli 315 GO?) hr 36% 0% 28% 35% Enterococcus 1,110 (£0?) br! 40% 4% 44% 11% Total Coliforms 2,090 GO?) hr 33% 2% 49% 15% Metals Copper 0.014 kepiaire- 49% 2% 29% 20% [ron ZA kg hr'! 13% 27% 50% 10% Lead 0.0060 kg hr=! 11% 1% 39% 50% Nickel 0.0003 kg hr“! 0% O% 100% 0% Zinc 1.74 ke hr! 16% 43% 38% 3% Nutrients Ammonia-N 26.6 kg hr“! 10% 63% 27% O% Nitrate-Nitrite 66.6 kovhrs! 10% 53% 36% 1% TKN 57.9 kevhrs 14% 53% 31% 2% Total Phosphorous 7A9 ke hr 21% 46% 31% 3% Creek, nutrient concentrations were consistently low. Bacteria concentrations were generally high throughout all stream reaches, with no apparent spatial pattern (Fig- ure 8). In some cases, metals concentrations appeared to reflect the locations of large inputs. For example, the 2002 in-stream copper concentrations were higher near the locations where large storm drains discharged (Figure 8). Discussion The characteristics and patterns of dry-season water quality observed in the SGR watershed are comparable to those seen in the neighboring urbanized wa- tersheds, such as the Los Angeles River (LAR) watershed (Ackerman et al. 2003) and Ballona Creek watershed (Stein and Tiefenthaler 2004). Similar to the LAR, 140 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES WalnutCreek San Jose Creek A) @ 2002 data B) 2002 median © 2003 data a= ——— 2003 median G > a a P : : ~~ 4 cal ~— 4 = e@ oc © & Ss 5 6 0 3 € = = = = ° E 5 ® ee aaa] < 27 fe fe} ° = £ c é ye 0; ¢——o———_¢ 0] ¢===<- A € 10 8 6 4 2 0 30 20 10 0 Stream Distance (km) Stream Distance (km) San Gabriel River Coyote Creek 8 8 o C) = a D) a. £ “3 oc ; = 64 3 8 6 < o ° i} — [s ~ = ® =| [e) fe} a5) a DS o 0 > D E S E = =—S 445 — = — 44 a 143] 14] < = < s) s) & e = E Da Ee 2 0 - ‘ ; er aS) ay | “=a 16 14 12 10 8 6 4 2 Ol 5-2 la Wz yo) 8 6 4 2 0 =2 Stream Distance (km) Stream Distance (km) Fig. 7. In-stream ammonia concentrations by stream and year (vertical arrows show WRP loca- tions). In Figure 7b, O km is the confluence of San Jose Creek and the San Gabriel River. the WRPs were determined to be the major source of flow and nutrients (there are no WRP discharges into Ballona Creek). Non-point source discharges are the major source of bacteria in all three watersheds. Similar to the LAR watershed, the source of metals loading varied by individual metal, with storm drains being the predominant source of most metals. In both the LAR and the SGR, WRPs were the predominant source of zinc. Unlike the LAR watershed, however, copper loading resulted primarily from storm drains in the SGR. This difference is likely due to higher detection limits used in the LAR study (e.g. in the LAR study, lead and iron detection limits were 10 and 200 ug/L, respectively and in this study 2 and 50 ug/L), which resulted in many more storm drain samples having “‘non- detect”” values, causing the WRPs to appear to be the major source of copper. This conclusion is further supported by the fact that storm drain concentrations SAN GABRIEL RIVER WATER QUALITY 14] WalnutCreek San Jose Creek 105 105 ° | es : an | ee = S 104 $ N ° 4 OQ 9 5 | 3 io) a 4 =o ae ee 4 = = 102 © : / \ 2 © os El be ee pea 9 109 5 | = R= ie) 8 | oO ° 77) rT 16) 4 (6) 71! [and oO i) © 1 O. 8 z u s oo b @ 2002 data ig 1 si © 8 Og to E 2002 median & : 5 S$ 8 1 © 2002 data 1 E Ss... § + ——— 2002 median | at “tt ” 10! r 1 10! 10 8 6 4 2 0 30 20 10 0 Stream Distance (km) Stream Distance (km) San Gabriel River Coyote Creek 10 = 10° 7 ® a J C) iF S Db) | | as w ay a o aa, P E 1075 ro E 10S ij = ; S) ae ° oO J S a fe} oO oO 4 = | 3 2 = OS Zz © 3 Zz 4 = Ss ° ° o | ” | o = ; SS : oc Pe 103 =F } 8 10° E = 12) 7 Oo a = 8 » 1 6->4-~_¢_---@e-----= g 8 8 Be | c= z | ] 5 10! if T T T T t T T T 10! T T T T T T t 6p i4= 122 M06 644-2 19 -2 (Aae2e eee teSs “Ge aes 4-2) O° =2 Stream Distance (km) Stream Distance (km) Fig. 8. In-stream Enterococcus concentrations by stream and year (vertical arrows show WRP locations). In Figure 8b, 0 km is the confluence of San Jose Creek and the San Gabriel River. in the SGR were comparable to those observed in Ballona Creek, where detection limits were similar to those used in the SGR. The manner in which samples with nondetectable levels of a particular metal were treated may affect conclusions regarding distribution of load among sources. The degree that nondetectable values influence general conclusions about loading depends on the frequency of nondetectable values. In our analyses, we assumed that samples below the detection limit had a concentration of zero. Due to the large volume input by the WRPs, small differences in these estimates can have a dramatic effect on the overall distribution of trace metal sources (Figure 10). For example, assuming that nondetectable samples for nickel were equal to a concen- tration of zero led to an estimation that storm drains account for 100% of the nickel mass. If this assumption were changed to a concentration equal to one-half 142 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES WalnutCreek San Jose Creek 35 40 A) @ 2002 data B) 30 2002 median 2003 data saul | ——— 2003 median 307 © ay ay ~ 5) © ee ee ® 20+ ‘ Es | es oO oY O eae Ses LG O x 4 = 2 O. = Oe 29 peas ~ ® 45 x = om) le 5 ~~ i yy (°) 5 § SS \ a now \ 0-7 0 - ee 10 8 6 4 2 0 30 20 10 0 Stream Distance (km) Stream Distance (km) San Gabriel River Coyote Creek 35 Ee C) D) 35 30 - 30 =, ae 25 5 © a pm BI =! Say S oa —_I 3 oli : 3 ; — 27% 3 = 204 a © © ° © c > o = is) =| oe! @ Oo a 15 4 4 Oo W te) & O 2 g O 9 ig, 1. F a % 104 2 O e fe) = - ea KE = 6 : 0 4 === === t 0 = SS 8) 16 4 12> 0S 6 4 2 Onn-2 14 ot eG) 8 6 4 2 0 -2 Stream Distance (km) Stream Distance (km) Fig. 9. In-stream copper concentrations by stream and year (vertical arrows show WRP locations). In Figure 9b, 0 km is the confluence of San Jose Creek and the San Gabriel River. the detection limit, the WRPs would become the dominant source for nickel as well as five of the six other metals analyzed. Although the magnitude of constituent concentrations varied from year to year, the general spatial patterns were consistent. For example, the ranges of measured storm drain flow and the distribution of flow among storm drains and between streams was generally consistent (Figure 2). Likewise, the pattern of storm drain concentrations for a given class of constituents was consistent between the two sampling events. For example, relatively few drains had high concentrations of metals and nutrients, whereas most drains had high concentrations of bacteria (Figure 4). The ubiquitously high bacteria concentrations reflect a consistent source being generated from the urban land uses in the watershed. Other non- SAN GABRIEL RIVER WATER QUALITY 100 % 80 % 60 % 40 % 20 % Percent Total Load Non Detect = 0 143 0% s Chromium Copper T Iron T Lead Nickel Zinc Non Detect = 1/2 Detection Limit 100 % = 80 % + 60 % - 40 % + Percent Total Load 20 % + ee eee 0% Chromium Copper Iron Lead T T Nickel Zinc Non Detect = Detection Limit 100 % 80 % 60 % 40 % Percent Total Load 20 % 7 0% T Chromium Copper Nickel Zinc (55) Large NPS WRP Ml Storm Drain Fig. 10. The effect of detection limits on the aggregated trace metal loadings using data from both sampling events. human sources, such as horses, birds, and dogs, and in-channel growth likely also contribute to the high levels observed. In general, spatial patterns of in-stream water quality correspond to the locations of dominant discharges for each con- stituent. For example, in-stream nutrient concentrations were highest downstream of WRP discharges, whereas in-stream metals concentrations were highest down- stream of areas where storm drains with high metals concentrations discharged. The consistently high bacteria concentrations throughout the system make estab- 144 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES lishing linkages between sources and receiving water concentrations more diffi- cult. In addition, potential in-stream sources of bacteria (e.g., birds or regrowth) were not evaluated in this study. Nevertheless, the patterns observed in this study were consistent with those observed in the LAR and Ballona watersheds and generally indicate a direct link between source inputs and in-river concentrations. Inter-annual variability in metals concentrations was similar to or slightly less than the typical ranges seen in Ballona Creek and LAR (Ackerman et al. 2003). However, inter-annual variations in bacteria concentrations were higher than typ- ically seen in other systems. This may be due to the lack of replication in this study, which would serve to amplify the inherently large fluctuations often seen in bacteria concentrations. Because the goal of this study was to provide a syn- optic view of water quality, increased spatial coverage of samples was prioritized over replication at individual locations. Inclusion of such replication would have likely reduced inter-annual variability in bacteria concentrations. Nevertheless, the pattern of high concentration of bacteria in both source inputs and receiving wa- ters was consistent between years. In contrast, differences in nutrient loading from the WRPs between 2002 and 2003 (and the resultant in-stream concentrations) were a result of changes in treatment practices (Figures 6b and 6c). In the interval between the two surveys, nitrification and denitrification facilities were installed at the WRPs. Decreases in measured average ammonia concentrations in the WRP effluent from 8.01 to 1.40 mg/L between 2002 and 2003 reflect this additional level of treatment. Similarly, in-stream concentrations downstream of the WRP discharges also decreased from 2002 to 2003. For example, the median ammonia concentration downstream of the San Jose Creek WRP decreased from 5.3 to 0.6 mg/L. This significant de- crease in ammonia further demonstrates the influence of this source on in-stream water quality. Conclusions The results from this study are similar to those seen in the Los Angeles River. Storm drains were the primary source of bacteria and most metals, while the WRPs the main source of nutrients. The instream water quality reflects these inputs and was consistent between the two samplings. The storm drain water quality concentrations and flow were highly variable; however, but variability was similar between the two surveys. Acknowledgements This study was funded by the Los Angeles Regional Water Quality Control Board, the Los Angeles County Sanitation Districts, the Los Angeles County Department of Public Works, the City of Downey, and the Southern California Coastal Water Research Project (SCCWRP). The authors would like to acknowl- edge the assistance of the Los Angeles/San Gabriel Rivers Watershed Council, Friends of the San Gabriel River, and U.S. EPA Region IX. The authors are greatly indebted to the many citizen volunteers who volunteered for a day of training and a day of sample collection for each survey. Without their participa- tion, the comprehensive characterization of the watershed would not have been nearly as complete. SAN GABRIEL RIVER WATER QUALITY 145 Literature Cited Ackerman, D., K. Schiff, H. Trim and M. Mullin. 2003. Characterization of water quality in the Los Angeles River. Bulletin of the Southern California Academy of Sciences 102: 17-25. Bay, S.M., D.J. Greenstein, S.-L. Lau, M.K. Stenstrom and C.G. Kelley. 1996. Toxicity of dry weather flow from the Santa Monica Bay Watershed. Bulletin of Southern California Academy of Sci- ences 95: 33-45. Hamilton, D.M. 1992. Hydrologic Assessment for Riparian Restoration Projects. Paper presented at the Environmental Engineering, Saving a Threatened Resource in Search of Solutions, Pro- ceedings of Environmental Engineering Sessions Water Forum °92, Baltimore, Maryland. LACDPW. Los Angeles County Department of Public Works. 2004. Imported and Reclaimed Water Data 2002-2003 Final. (http://www.ladpw.org/wrd/spreadingground/watercon/), April 29, 2004. Roesner, L.A. and B.P. Bledsoe. 2003. Physical Effects of Wet Weather Flows on Aquatic Habitats: Present Knowledge and Reasearch Needs. Water Environment Research Foundation. Fort Col- lins, CO. Schiff, K. 1997. Review of existing stormwater monitoring programs for estimating Bight-wide mass emissions from urban runoff. pp. 44—55 in: D. Hallock (ed.), Southern California Coastal Water Research Project Annual Report 1995—96. Westminster, CA. Schueler, T.R. and H.K. Holland. 2000. The Practice of Watershed Protection. Center for Watershed Protection. Ellicott City, MD. Stein, E.D. and L.L Tiefenthaler. 2004. Characterization of dry weather metals and bacteria in Ballona Creek. Southern California Coastal Water Research Project Technical Report #427. Accepted for publication 22 December 2004. Bull. Southern California Acad. Sci. 104(3), 2005, pp. 146-151 © Southern California Academy of Sciences, 2005 Research Notes Rediscovery of the Laomediid Shrimp Naushonia macginitier (Glassell, 1938) (Crustacea: Decapoda: Thalassinidea: Laomediidae) from off Southern California Lindsay Sirota! and Joel W. Martin ' San Diego State University, 5500 Campanile Drive, San Diego, CA 92182. e-mail: h2obug13 @earthlink.net * Natural History Museum of Los Angeles County, 900 Exposition Boulevard, Los Angeles, CA 90007, e-mail: jmartin@nhm.org Introduction The decapod crustacean genus Naushonia Kingsley, 1897, currently contains seven species of rare, burrowing shrimp-like thalassinoids (Goy and Provenzano 1979; Martin and Abele 1982; Berggren 1992; Alvarez et al. 2000). Species are known from mud and other soft sediments in temperate and tropical localities worldwide, with the exception of Asia (e.g. N. crangonoides from the east coast of the U.S, N. panamensis from the Pacific coast of Panama, N. perrieri from the Red Sea, N. lactoalbida from Mocambique, N. manningi from the Bahamas), but in almost all cases each species 1s known from very few specimens. The sole species known from the west coast of North America is Naushonia macginitiel (Glassell), described originally (as Homoriscus macginitiei) by Glassell based on two ovigerous females collected from La Jolla, California, in 1935 (Glassell 1938: 414). Soon after the species was described, Chace (1939) reassigned both known species of Homoriscus to the genus Naushonia. Goy and Provenzano (1979) brief- ly reviewed the genus Naushonia and mentioned a total of four specimens of N. macginitiei examined by them (including the ovigerous female paratype) in the collections of the U. S. National Museum of Natural History (USNM). However, Goy and Provenzano (1979) did not provide information on the collecting locality of those specimens, although that information has now been provided to us by the USNM (see below). To date, the species is known from only two reports in the literature and a total of five specimens, possibly explaining why the species was not listed by Williams et al. (1989) in their list of the known decapod Crustacea from North America (an omission that has now been corrected by McLaughlin et a/. 2005). In addition to the published reports noted above, additional specimens have been encountered during regional monitoring efforts of the Southern California Coastal Water Re- search Project (SCCWRP; see www.sccwrp.org). Stations where the species was collected during the SCCWRP Bight 98 project were 2259 (at a depth of 11.2 m; | specimen), 2259 (10.9 m; 1 specimen), and 2264 (10.1 m; 2 specimens), all of which were in San Diego Bay. During the SCCWRP Bight 03 project, one spec- imen was found at each of the following stations: BRI 17 (7 m), BRI 19 (9 m), and 4116 (4 m), with all stations again being in San Diego Bay (Don Cadien and Ananda Ranasinghe, personal communication). Additionally, there are unpub- 146 REDISCOVERY OF THE LAOMEDIID SHRIMP NAUSHONIA MACGINITIEI 147 32° 44° W Pacific | Ocean 32° 37’ W 2km | 117° 14" W 117° 07’ W Fig. 1. Map of San Diego Bay with star indicating the location of the eelgrass harvesting exper- iment and specimen collection site. lished reports by southern California biologists of laomediid larvae that almost undoubtedly belong to this species (as there are no other laomediids known from southern California) (Don Cadien, personal communication). In January of 2004, a specimen of Naushonia macginitiei was collected from a large, shallow eelgrass (Zostera marina) bed south of Silver Strand Beach in San Diego Bay, California, marking the first time the species has been collected in nearly 70 years (apart from the unpublished observations noted above). The specimen, apparently only the sixth of this species ever recorded in print, was photographed soon after collecting, allowing us to comment on the coloration of the species for the first time. Methods and Materials Collection of the specimen was made by Brendan Reed and Lindsay Sirota as part of an ongoing San Diego State University master’s thesis project focusing on the effects of harvesting eelgrass beds. The study site is San Diego Bay, a crescent shaped bay extending 25 km south from its mouth located near Point Loma Gies)): Study plots are in a large continuous eelgrass meadow (Zostera marina) located in southern San Diego Bay, just south of Silver Strands State Beach (Fig. 1). This expansive bed is fairly uniform in topography and is never fully exposed, although at extreme low tides the grass can be less than 1.5m deep. The currents in the south bay are quite mild, and water residence time can exceed a month. The sediment at this site consists of fine mud particles. 148 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES The specimen was collected during faunal surveying in January 2004. Epifauna were sampled with a 0.25m? throw-trap consisting of a circular metal frame with an attached 2mm vexar mesh collar that stands Im high. The narrow opening of the conical collar (30 cm diameter) keeps epifauna from escaping the throw trap in field trials. Each throw trap was sampled with a diver-operated airlift suction sampler for one minute. Epifauna were collected into a narrow mesh bag (1600ym), rinsed and transferred into a plastic storage bag where they were frozen for future sorting in the laboratory. The specimen was collected from a plot that had approximately 20% eelgrass removed by way of the scarring method, which removes large portions of eelgrass including all aboveground shoots and attached rhizomes. Sampling was conducted from late morning to early afternoon and in water no deeper than 2.5m. Photo- graphs, taken with a digital Nikon Coolpix 995 (3.3 megapixel), were made short- ly after the specimen was defrosted and sorted. The specimen is deposited in the Crustacea collections of the Natural History Museum of Los Angeles County as LACM CR 2004-002.1. Morphology The specimen is immediately identifiable as a species of Naushonia by the elongate, subchelate, and somewhat oversized chelipeds (approximately equal in length to the carapace in this species and in most others; Fig. 2A, B), the sculp- tured carapace with well-developed linea thalassinica and broad, short rostrum (Fig. 2A, C), the similar morphology of pereiopods 3—5 but the distinctly different dactylus of pereiopod 2, the well developed suture on both uropods, and other characters of the genus (see Goy and Provenzano 1979; Alvarez et al. 2000). Our specimen in general agrees well with the original description given by Glassell (1938). Goy and Provenzano (1979), comparing USNM specimens of N. macgin- itiei (including the ovigerous female paratype) with those of other species in the genus, noted slight intra-specific variability in the number of teeth on the margin of the antennal scale (7 or 8), number of movable spines on the dactylus of the third pereiopod (20—22 in the paratype; up to 24 in two other specimens) and fourth pereiopod (15 to 18 spines). Carapace length of the specimens measured by them ranged from 7.6 mm in the paratype (the largest known to them) to 6.5 mm in USNM 144492 (which is actually USNM 171606 according to K. Reed; see below). Measurements and meristic counts in our specimen fall within these ranges, and the carapace length of our specimen (7.7 mm) 1s only slightly larger than the largest known specimen to date (the female paratype, measured by Goy and Provenzano [1979] at 7.6 mm carapace length). The abdomen length of our specimen is approximately 11.5 mm (approximate because of the bend of the abdomen), for a total length (rostrum to tip of telson) of approximately 19.2 mm. The color in life is a surprisingly bright orange, with some of the appendages speckled with white or beige, lending an almost banded appearance to the pe- reiopods, and with the dorsal surface of the abdomen a more uniform beige or cream (Fig. 2). To our knowledge, this is the first observation of coloration in this species. Known Distribution and Habitat To date, Naushonia macginitiei has been reported only twice in the literature, first by Glassell (1938) in the original description (as Homariscus macginitiei) REDISCOVERY OF THE LAOMEDIID SHRIMP NAUSHONIA MACGINITIEI 149 Fig. 2. LACM CR 2004-002.1, specimen of Naushonia macginitei (Glassell) from San Diego Bay described herein. A, entire specimen, dorso-lateral view. B, right and left chelipeds. C, rostrum and front half of carapace, dorsal view. D, right chela. E, opened left chela. and later by Goy and Provenzano (1979). Goy and Provenzano (1979) examined additional specimens housed at the USNM, but did not give details of where those specimens were collected. The additional material discussed by Goy and Prov- enzano included collections made the Allan Hancock Pacific Expeditions using the R/V Velero III, and these records extended the known range south to Sonora, Mexico, and to Costa Rica (see below). In our introduction, we mentioned un- published records of an additional 6 specimens, all collected from San Diego Bay and, interestingly, from depths of 4 to 11 m rather than the intertidal. Glassell (1938) indicated that the holotype, one of two ovigerous females from La Jolla, California, was deposited in San Diego and assigned “cat. no.1120, San Diego Society of Natural History.’’ The holotype now resides in the San Diego 150 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES Natural History Museum where it 1s catalogued with the following information: Homoriscus macginitiet; holotype #3924; Crustacea acc.no. 1120; 1 specimen; female (with 1120 on the tag in the jar); ““Glassell 1938, p 414” written on the label (pers. comm., Paisley Cato, San Diego Natural History Museum). The other female (the paratype) was deposited at the USNM, where it is now catalogued as USNM 171605 (see below) Apart from the holotype, the known collections of this species (all housed at the USNM) are as follows (K. Reed, USNM, pers. comm): USNM 155480, Naushonia ct. macginitiei (Glassell), North Pacific Ocean, Wa- fer Bay, Cocos Island: 5° 32’ 45” North 87° 00’ 10” West, rocky shoreline, coll. | March 1933, Allan Hancock Pacific Expedition, Velero III, station 105-33, iden- tified by T. Biffar. USNM 171604, Naushonia macginitiei (Glassell), Pacific Ocean, Newport Bay, California, 33° 36’ 58” North 117° 54’ 12” West, North and East of highway 101 bridge, intertidal, —1.6 ft. tide, dredged sand flats along shore, coll. 18 December, 1941, Allan Hancock Pacific Expedition, Velero III, station 1442-41, identified by O. Hartman. USNM 171606, Naushonia macginitiei (Glassell), North Pacific Ocean, Gulf of California, Ensenada De San Francisco, Sonora, Mexico, coll. 30 March 1937, Allan Hancock Pacific Expedition, Velero III, station 739-37, identified by J. W. Goy. USNM 171605, Homoriscus macginitiei Glassell (Paratype), 1 female, North Pacific Ocean, La Jolla, California, U.S.A., coll. 4 March 1935 (by G. Mac- Ginitie), identified (described) by S. A. Glassell. Goy and Provenzano (1979) must have been unaware of the Costa Rica record sent to us by K. Reed (USNM 155480 above), as it is not among the USNM material they listed. According to Karen Reed (USNM), there are also two minor errors in the paper by Goy and Provenzano: the lot they listed as USNM 144492 is actually USNM 171606, and there is only | specimen (rather than 2) in that lot (K. Reed, pers. comm.). However, Goy and Provenzano provided measure- ments and detailed anatomical observations for the two specimens in that lot, so there is some uncertainty surrounding the specimen(s). To these records we now add the new specimen from San Diego Bay (LACM CR 2004-002.1), very close to the type locality. Thus, the known range of the species is from southern California south to Sonora, Mexico, and to the Gulf of Nicoya, Costa Rica. Although all members of the genus Naushonia are assumed to be burrowers in mud or sand (e.g. see Goy and Provenzano 1979; Alvarez et al. 2000), there has always been some question as to the habitat of N. macginitiei. Glassell (1938) noted that the original 2 specimens were found (by G. E. MacGinitie) “‘in a small pool at extreme low water, after he had turned some stones in search of Typhlo- gobius californiensis Steindacher (the Blind Goby)’. In addition to these two southern California specimens, two additional individuals were also collected from intertidal habitats, one from the Cocos Islands and the other from Newport Bay. Our finding of N. macginitiei in a large and rather uniform eelgrass meadow might indicate that the species can occur in more than one type of habitat. As this is the only known specimen collected in eelgrass it is difficult to speculate as to the importance of this habitat to N. macginitiei. REDISCOVERY OF THE LAOMEDID SHRIMP NAUSHONIA MACGINITIEI it Acknowledgments This work was supported in part by grants from the U.S. National Science Foundation to D. K. Jacobs and J. W. Martin (DEB 9878193) and to C. Cun- ningham et al. (DEB 0120635) as well as by the Unified Port of San Diego. We also thank the following persons for assistance in the field; for bringing the dis- covery to our attention; for helping us locate information, literature, and speci- mens of Naushonia; or for helpful comments on earlier drafts of the manuscript: Brendan Reed, Constance Gramlich, Greg Jensen, Rafael Lemaitre, Karen Reed, Mary Wicksten, Don Cadien, Ananda Ranasinghe, George Davis, and Kevin Hov- el. NOTE ADDED IN PROOF While the current paper was in press, the following publication, which expands the known range of the genus Naushonia to the western Pacific, came to our attention: Komai, T. 2004. Rare mud shrimp genus Naushonia Kinglsey (Decapoda: Thal- assinidea: Laomediidae) from Japan: description of a new species and new record of N. lactoalbida Berggren. Crustacean Research 33: 15—26. Literature Cited Alvarez, E, J.L. Villalobos, and T.M. Iliffe. 2000. Naushonia manningi, new species (Decapoda: Thal- assinidea: Laomediidae), from Acklins Island, Bahamas. J. Crustacean Biology, 20: 192-198. Berggren, M. 1992. Naushonia lactoalbida, new species (Decapoda: Thalassinidea: Laomediidae), a mud shrimp from Inhace Island, Mogambique. J. Crustacean Biology, 12: 514—522. Chace, EA. 1939. On the systematic status of the crustacean genera Naushonia, Homoriscus, and Coralliograngon. Annals and Magazine of Natural History. 11(3): 524-530. Glassell, S.A. 1938. New and obscure decapod Crustacea from the West American Coasts. Trans. San Diego Soc. of Nat. Hist. 8(33):411—454. Goy, J.W. and A.J. Provenzano Jr. 1979. Juvenile morphology of the rare burrowing shrimp Naushonia crangonoides Kingsley, with a review of the genus Naushonia (Decapoda: Thalassinidea: La- omediidae). Proc. Biol. Soc. Wash. 92:339-—359. Martin, J.W. and L.G. Abele. 1982. Naushonia panamensis, new species (Decapoda: Thalassinidea: Laomediidae) from the Pacific coast of Panama, with notes on the genus. Proc. Biol. Soc. Wash. 95(3):478—483. McLaughlin, P. A., D. K. Camp, L. G. Eldredge, D. L. Felder, J. W. Goy, H. H. Hobbs III, B. Kensley, R. Lemaitre, and J. W. Martin. 2005. Order Decapoda. In: D. Turgeon, editor, Common and Scientific Names of Aquatic Invertebrates of the United States and Canada. American Fisheries Society Special Publication 31: 1—545. Accepted for publication 16 March 2005. Bull. Southern California Acad. Sci. 104(3), 2005, pp. 152-153 © Southern California Academy of Sciences, 2005 The Scythe Butterflyfish, Prognathodes falcifer (Pisces: Chaetodontidae), Observed as a Facultative Cleaner Robert N. Lea! and Daniel V. Richards? ‘California Department of Fish and Game, Marine Region, 20 Lower Ragsdale Drive, Monterey, California 93940 E-mail: rnlea@ comcast.net 2Channel Islands National Park, 1901 Spinnaker Drive, Ventura, California 93001 Cleaning behavior in fishes is a well-documented phenomenon and involves a number of teleostean families (Limbaugh 1961; Deloach 1999). This behavior is expressed especially well in tropical gobies (Gobiidae), wrasses (Labridae), and butterflyfishes (Chaetodontidae). While surveying fish and invertebrate populations using SCUBA at Islas San Benito, Baja California, Mexico (ca. lat. 28°18.7'N, long. 115°32.6’W) we ob- served cleaning behavior by the scythe butterflyfish, Prognathodes falcifer (Hubbs & Rechnitzer, 1958). This, to our knowledge, is the first report of cleaning be- havior by this species; the nature of its cleaning also appears to be unique within the Chaetodontidae. On 9 August 2001 at ca. 0820, at San Benito del Este, the easternmost of the three San Benito islands, we observed a large kelp bass, Paralabrax clathratus, and several scythe butterflyfish, at a depth of ca. 17 m in a relatively small horizontal cave. The dimensions of the cave (or large horizontal crevice) were ca. 2 m in length, 1 m deep, and 0.75 m in height. The kelp bass was inside the cave and oriented horizontally and essentially parallel to the cave opening. Initially, we were impressed by its unusually large size, ca 600 mm total length. Several scythe butterflyfish were also noticed in the cave but at each end and not in close association with the kelp bass. The kelp bass then appeared to become rigid in posture and lower (or drop) its pectoral fins. Almost immediately, three butterflyfish (all ca. 150 mm total length) swam to the sides of the kelp bass, took diagonal positions, and appeared to start clean- ing the larger serranid; we assumed they were picking external parasites (Fig. 1). One butterflyfish took a position to the anterioventral portion of the host kelp bass while the other two butterflyfish took posteriorventral positions on the body, one fish on each side. We observed this behavior for ca. 30 seconds. The prolonged snout and jaw structure of the scythe butterflyfish appears to be preadapted for cleaning (Ferry-Graham et al. 2001). The barberfish, Johnrandallia nigrirostris, another eastern Pacific chaetodontid, is a well-documented cleaner (Hobson 1965, 1969; Burgess 1978; Allen 1979; Thomson et al. 2000). The majority of butterflyfishes exhibiting cleaning behavior appear to clean their host while it is positioned up in the water column, perhaps making them- selves more visible to the cleaners (Burgess 1978). In the example we observed, the host took a position in a somewhat secluded situation that harbored several E52 BUTTERFLYFISH CLEANING BEHAVIOR [5S Fig. 1. Depiction of scythe butterflyfish cleaning a kelp bass at Islas San Benito on 9 August 2001. scythe butterflyfish, one of the more secretive species of chaetodontids. In the case of Prognathodes falcifer, it is likely that cleaning is a non-obligate and infrequent mode of behavior. In over one hundred dives by us at the San Benito islands, covering an 18-year period, this is the first instance of cleaning by the scythe butterflyfish that we have witnessed. John McCosker of the California Academy of Sciences (pers. comm., April 2002), in many years of diving at the Galapagos Islands has never noted this species to be involved in cleaning. Perhaps secretive or clandestine cleaning is a more common mode of behavior than re- alized in chaetodontids. Additional observations of cleaning behavior by other cave- and crevice-dwelling species may be noted as a result in the future. Acknowledgments We thank John McCosker for providing comments and sharing his observations of scythe butterflyfish at the Galapagos Islands. Daniel Pondella was a dive partner during the 2001 San Benito trip and provided valuable comments. Larry Allen, Mark Helvey, Timothy Tricas and three anonymous reviewers also provided com- ments to the manuscript. Briana Brady prepared the illustration. Literature Cited Allen, G. R. 1979. Butterfly and angelfishes of the world. Vol. 2. John Wiley & Sons. Burgess, W. E. 1978. Butterflyfishes of the world. TRH. Publ., Inc. Ltd. Deloach, N. 1999. Reef fish behavior. New World Publ., Inc. Ferry-Graham, L. A., P. C. Wainwright, C. D. Hulsey, and D. R. Bellwood. 2001. Evolution and mechanics of long jaws in butterflyfishes (family Chaetodontidae). J. Morphology 248(2):120— 143. Hobson, E. S. 1965. A visit with el barbero. Underwater Naturalist 3(3):5—10. Hobson, E. S. 1969. Comments on certain recent generalizations regarding cleaning symbiosis in fishes. Pacific Science 23(1):35-39. Limbaugh, C. 1961. Cleaning symbiosis. Scientific American. 205(2):42—49. Thomson, D. A., L. T. Findley, and A. N. Kerstitch. 2000. Reef fishes of the Sea of Cortez: the rocky- shore fishes of the Gulf of California. Revised edition. The University of Texas Press. Accepted for publication 22 December 2004. Bull. Southern California Acad. Sci. 104(3), 2005, pp. 154—156 © Southern California Academy of Sciences, 2005 Record of a White Sturgeon, Actpenser transmontanus from Bahia De Todos Santos, Baja California, Mexico, Found at the Ensenada Sea Food Market J. A. Rosales-Casian and R. Ruz-Cruz Centro de Investigacion Cientifica y de Educacién Superior de Ensenada, B.C. Division de Oceanologia, Departamento de Ecologia Grupo e Ecologia Pesquera Km 107 carretera Tijuana-Ensenada, Ensenada, B.C., México The white sturgeon, Acipenser transmontanus (Richardson 1836), is an anad- romous fish that lives primarily in freshwater or estuaries, and infrequently me- anders in the ocean. Most of fish are found in river systems, with the Sacramento- San Joaquin River system (California) and Columbia River system (Oregon/Wash- ington) containing the largest populations (Love 1996). In summer, they migrate into shallow warm waters of rivers or toward the shores for breeding purposes. They are benthic and long-lived fish species that inhabit the shallow sand and mud bottoms (Love 1996). The distribution of Acipenser transmontanus range from Northern Baja California (Love 1996), or from Ensenada, Baja California (México) to Gulf of Alaska (Miller and Lea 1972). Bahia de Todos Santos is located at Ensenada, Baja California, México, (31°40’-31°56'N, 116°36’—116°50'W), and fish studies at the bay began in the early 1980’s with a variety of gear types including spear guns at kelp beds (Diaz- Diaz 1983; Diaz-Diaz and Hammann 1987), trawl tows on sandy bottoms Ham- mann and Rosales-Casian (1990), and creel surveys (Rodriguez-Medrano 1993). In addition, research on the fish community of Todos Santos bay and also in Bahia and Costa de San Quintin was conducted between 1992 and 1995 using five different gears: beam-trawl, otter-trawl, beach-seine, gillnet, and hook-and- line (Rosales-Casian 1997a, 2004). Recently, a study of the artisanal fishery from eight fishing camps along northwestern coast of Baja California was also com- pleted (Rosales-Casian and Gonzalez 2003). All those studies failed to collect any specimens of white sturgeon. The Seafood Market of Ensenada Port has been surveyed monthly since Sep- tember 2000 (Hernandez-Hernandez 2002). During this monitoring program on March 15, 2003, we observed a white sturgeon (Acipenser transmontanus), which was captured on same day with a bottom trap close to the Isla de Todos Santos located in Bahia de Todos Santos. The specimen was fresh and complete but eviscerated, and the testes were still in the body. This male was in stage III: maturation (Nikolsky 1963; Cailliet et al 1986). The white sturgeon was 1,228- mm total length (TL) and a somatic weight of 6,366 g. In California waters, the males mature at TL 1,097—1,828 mm (Love 1996). The white sturgeon was identified by the combination of the following char- acteristics: body coloration was grayish-white with five rows of bony plates (scutes) on its body. The head was short and robust with the four long barbells (Scm) located in the front and closer to the snout tip than to the mouth. The 154 WHITE STURGEON FROM ENSENADA SEA FOOD MARKET 155 mouth was underneath the head, and the number of the midlateral bony plates was 40. Another white sturgeon, Acipenser transmontanus, was collected at Flat Rock, Rancho Palos Verdes in Los Angeles County on April 24, 2003. SL 1,220, TL 1,940, and 20.5 kilos. It was caught in an overnight gill net set as part of a white seabass monitoring project (Pondella and Allen 2000). Latitude 33°47'54’'’N, Lon- gitude 118°24'73’'W, depth 6.3 meters (Daniel Pondella, personal communication, Vantuna Research Group, Occidental College, Los Angeles, CA). The record of this specimen is important because it reconfirms the southern range of white sturgeon, increases the list of fish species that have been collected or registered at Bahia de Todos Santos, Baja California, México, and re-establishes a well-documented reference. Acknowledgments We thank the fish vendors at the Mercado de Mariscos del Puerto de Ensenada, to allow our study and by the inconveniences of the fish handling during their operations. Literature Cited Cailliet, G. M., M. S. Love and A. W. Ebeling. 1986. A field and laboratory manual on their structure, identification and natural history. Wads Worth Publishing Company, Belmont California, USA. 194 p. Diaz-Diaz,. 1983. Aspectos troficos de algunas especies de peces asociadas a un manto de Macrocystis pyrifera en la Bahia de Todos Santos, Baja California (Primavera-Verano, 1982). Bachelor thesis. Escuela Superior de Ciencias Marinas (UABC), Ensenada, B.C. 61 p. Diaz-Diaz M. E. and M. G. Hammann. 1987. Relaciones troficos de los peces associadas a un manto de Macrocystis pyrifera en la Bahia de Todos Santos, Baja California, México. Ciencias Marinas 13(4):81-96. Hammann, M. G. and J. A. Rosales-Casian, 1990. Taxonomia y estructura de la comunidad de peces del Estero de Punta Banda y Bahia de Todos Santos, Baja California, México. Cap. 6:153-192. En Rosas-Velez J. de la y EK Gonzalez-Farias (eds). Temas de Oceanografia Biol6gica en Méx- ico. Universidad Autonoma de Baja California, Ensenada, B.C. 337 p. Hernandez-Hernandez, A. 2002. Composicion especifica de los peces escama comercializados en el Mercado de Mariscos del Puerto de Ensenada, Baja California, México. Facultad de Ciencias Biologicas, Universidad Aut6noma del Estado de Morelos. Cuernavaca, Morelos (México). 60 p. Love,,M. S. 1996. Probably more than you Want to know about the fishes of the Pacific coast. Really Big Press, Santa Barbara, CA. 215 p. Miller, D. J. and R. N. Lea. 1972. Guide to the coastal marine fishes of California. Bulletin of the California Department of Fish and Game No. 157, 235 p. Nikolsky, G. V. 1963. The ecology of fishes. Academic Press Inc., New York, USA. 329 p. Pondella, Daniel J., Il, and Larry G. Allen. 2000. The nearshore fish assemblage of Santa Catalina Island. In The Proceedings of the Fifth California Islands Symposium, David R. Browne, Kath- ryn L. Mitchell and Henry W. Chaney editors. Santa Barbara Museum of Natural History, Santa Barbara, California: 394-400. Richardson, J. 1836. The fish. In: Fauna Boreali-Americana; the zoology of the northern parts of British America. Part 3, Vancouver, Washington, USA. 327 p. Rodriguez-Medrano, M. del C. 1993. Descripci6n y andalisis de la pesca deportiva en Bahia de Todos Santos, Ensenada, B.C. M.S. Thesis, CICESE. 88 p. Rosales-Casian, J. A. 1997a. Estructura de la comunidad de peces y el uso de los ambientes de bahias, lagunas y costa abierta en el Pacifico norte de Baja California. Ph.D. Thesis, Ecologia Marina, CICESE. 201 p. Rosales-Casian, J. A. 1997b. Inshore soft-bottom fishes of two coastal lagoons on the northern Pacific coast of Baja California. CalCOFI Rep. 38:180-192. 156 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES Rosales-Casian, J. A. and J. R. Gonzalez. 2003. Abundance and importance of fish species from the artisanal fishery on the Pacific Coast of Northern Baja California. Bull. Southern California Acad. Sci. 102(2):51-65. Rosales-Casian, J. A. 2004. Composition, importance and movement of fishes from San Quintin Bay, Baja California, México. Ciencias Marinas 30 (1A):109-117. Accepted for publication 16 March 2005. Se Bull. Southern California Acad. Sci. 104(3), 2005, pp. 157-158 © Southern California Academy of Sciences, 2005 INDEX TO VOLUME 104 Ackerman, Drew. Dry-season Water Quality in the San Gabriel River Watershed. P25 Allen, Larry G., see Erisman, Brad E. Andrews, Allen H. Age and Growth of Spotted Sand Bass, Paralabrax macula- tofasiciatus, in Bahia de Los Angeles, Baja California, Mexico, with Age Validation using Otolith Edge Analysis. 14. Arellano, E. Solana, Diaz-Castaneda, Victoria Bearzi, Maddalena. Habitat Partitioning by Three species of Dolphins in Santa Monica Bay, California. 113 Bennett, Tony, see Andrews, Allen H. Cailliet, Gregor M., see Andrews, Allen H. Calleros, Jesus, see Ltideritz, Volker. Costa-Pierce, Barry A., see Reidel, Ralf. Diaz-Castaneda, Victoria. Structure and Composition of the Polychaete Commu- nity from Bahia San Quintin, Pacific Coast of Baja California, Mexico. 75 Erisman, Brad E. Color Patterns and Associated Behaviors in the Kelp Bass, Paralabrax clathratus (Teleostei: Serranidae). 45 Froeschke, John T. The Reef Fish Assemblage of the Outer Los Angeles Federal Breakwater, 2002—2003. 63 Gerlach, Frauke, see Liideritz, Volker. Gersberg, Richard M., see Liideritz, Volker. Gonzalez, A. de Leon, see Diaz-Castaneda, Victoria Ibarra-Obando, Silia E., see Quiroz-Vazquez, Patricia Tenes: Erin, see Andrews, Allen H. Jiipner, Robert, see Liideritz, Volker. Laman, Edward A., see Andrews, Allen H. Lea, Robert N. The Scythe Butterflyfish, Prognathodea falcifer (Pisces: Chaeto- dontidae), Observed as a Facultative Cleaner. 152 Liideritz, Volker. Biological Assessment of Tecate Creek (U.S.—Mexico) with Special Regard to Self-Purification. | Martin, Joel W., see Sirota, Lindsay Meling-L6pez, Alf E., see Quiroz-Vazquez, Patricia Pitt, Jerome, see Ltideritz, Volker. Pondella, Daniel J. Il, see Froeschke, John T. tS7 158 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES Quiroz-Vazquez, Patricia. Composition of the Epifaunal Community Associated with the Seagrass Zostera marina in San Quintin Bay, Baja California. 100 Reidel, Ralf. Feeding Ecology of Salton Sea Tilapia (Oreochromis spp.) 26 Richards, Daniel V., see Lea, Robert N Rosales-Casian, J. A. Record of a White Sturgeon, Acipenser transmontanus from Bahia de Todos Santos, Baja California, Mexico, Found at the Ensenada Sea Food Market. 154 Ruz-Cruz, R., see Rosales-Casian, J. A. Schiff, Kenneth, see Ackerman, Drew Sirota, Lindsay. Rediscovery of the Laomediud Shrimp Naushonia macginitiei (Glassell, 1938) (Crustacea: Decapoda: Thalassinidea: Laomediidae) from off Southern California. 146. Stapp, Paul. Microhabitat Segregation of Three Species of Pocket Mice (Genus Chaetodipus) in Coastal Baja California, Mexico. 36 Stein Eric D., see Ackerman; Drew INSTRUCTIONS FOR AUTHORS The BULLETIN is published three times each year (April, August, and December) and includes articles in English in any field of science with an emphasis on the southern California area. Manuscripts submitted for publication should contain results of original research, embrace sound principles of scientific investigation, and present data in a clear and concise manner. The current AIBS Style Manual for Biological Journals is recommended as a guide for contributors. Consult also recent issues of the BULLETIN. 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He or she should promptly and carefully read the proof sheets for errors and omissions in text, tables, illustrations, legends, and bibliographical references. He or she marks corrections on the galley (copy editing and proof procedures in Style Manual) and promptly returns both galley and manuscript to the Editor. Manuscripts and original illustra- tions will not be returned unless requested at this time. All changes in galley proof attributable to the author (misspellings, inconsistent abbreviations, deviations from style, etc.) will be charged to the author. Reprint orders are placed with the printer, not the Editor. CONTENTS Habitat Partitioning by Three species of Dolphins in Santa Monica Bay, California. Maddalena Bearzi Dry-season Water Quality in the San Gabriel River Watershed. Drew Ackerman, Eric D. Stein, and Kenneth Schiff Research Notes Rediscovery of the Laomediid Shrimp Naushonia macginitiei (Glassell, 1938) (Crustacea: Decapoda: Thalassinidea: Laomediidae) from off Southern California. Lindsay Sirota and Joel W. Martin The Scythe Butterflyfish, Prognathodedes falcifer (Pisces: Chaetodontidae), Observed as a Facultative Cleaner. Robert N. Lea and Daniel V. Richards Record of a White Sturgeon, Acipenser transmontanus from Bahia de Todos Santos, Baja California, Mexico, Found at the Ensenada Sea Food Market. J. A. Rosales-Casian and R. Ruz-Cruz Cover: Bottlenose dolphins socializing in Santa Monica Bay, CA. Photo: Maddalena Bearzi