A UNITED STATES DEPARTMENT OF COMMERCE PUBLICATION ^t-'O'Co^ V ^'«r,s o< ' NOAA TR NMFS SSRF-639 NOAA Technical Report NMFS SSRF-639 U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Marine Fisheries Service A Hydrographic Survey of the Galveston Bay System, Texas, 1963-66 E. J. PULLEN, W. L. TRENT, AND G. B. ADAMS Marine Biological Laboratory LIBRARY OCT H 1992 Woods Hole, Mass. SEATTLE, WA. October 1971 NOAA TECHNICAL REPORTS National Marine Fisheries Service, Special Scientific Report-Fisheries Series The major responsibilities of the National Marine Fisheries Service (NMFS) are to monitor and assess the abundance and geographic distribution of fishery resources, to understand and predict fluctuations in the quantity and distribution of these resources, and to establish levels for optimum use of the resources. 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NOAA Technical Reports NMFS SSRF are available free in limited numbers to governmental agencies, both Federal and State. They are also available in exchange for other scientific and technical publications in the marine sciences. Individual copies may be obtained (unless otherwise noted) from NOAA Publications Section, Rockville, Md. 20852. Recent SSRF's are: 601. Effect of flow on performance and behavior of Chinook salmon in fishways. By Clark S. Thomp- son. March 1970, iii + 11 pp., 8 figs., 3 tables. 586. The Trade Wind Zone Oceanography Pilot Study. Part VII : Observations of sea birds March 1964 to June 1965. By Warren B. King. June 1970, vi -I- 136 pp., 36 figs., 11 tables. 591. A bibliography of the lobsters, genus Homarus. By R. D. Lewis. January 1970, i -f- 47 pp. 592. Passage of adult salmon and trout through pipes. By Emil Slatick. January 1970, iii + 18 pp., 8 figs., 12 tables. 594. Seasonal and areal distribution of zooplankton in coastal waters of the Gulf of Maine, 1967 and 1968. By Kenneth Sherman. July 1970, iii + 8 pp., 6 figs., 3 tables. 595. Size, seasonal abundance, and length-weight re- lation of some scombrid fishes from southeast Florida. By Grant L. Beardslfey, Jr., and William J. Richards. May 1970, iii + 6 pp., 5 figs., 2 tables. 596. Fecundity, multiple spawning, and description of the gonads in Sebastodes. By John S. MacGregor. March 1970, iii + 12 pp., 6 figs., 7 tables. 597. Fur seal investigations, 1967. By Bureau of Commercial Fisheries Marine Mammal Biological Laboratory. March 1970, vii -f- 104 pp., 31 figs., 79 tables. 599 Diagnostic characters of juveniles of the shrimps Penaeiis aztccus aztecus, P. duorarum diiorariim, and P. brasiliensis (Crustacea, Decapoda, Penaei- dae). By Isabel Perez Farfante. February 1970, iii -f 26 pp., 25 figs. 600. Birectilinear recruitment curves to assess in- fluence of lake size on survival of sockeye salmon {Oncorhynclms nerka) to Bristol Bay and fore- cast runs. By Ralph P. Silliman. March 1970, iii -f 9 pp., 13 figs., 2 tables. 602. Biological characteristics of intertidal and fresh- water spawning pink salmon at Olsen Creek, Prince William Sound, Alaska, 1962-63. By John H. Helle. May 1970, iii -|- 19 pp., 11 figs., 5 tables. 603. Distribution and abundance of fish in the Yakima River, Wash., April 1957 to May 1958. By Ben- jamin G. Patten, Richard B. Thompson, and Wil- liam D. Gronlund. June 1970, iii + 31 pp., 26 figs., 37 tables. 604. The flora and fauna of a basin in central Florida Bay. By J. Harold Hudson, Donald M. Allen, and T. J. Costello. May 1970, iii + 14 pp., 2 figs., 1 table. 605. Contributions to the life histories of several penaeid shrimps (Penaeidae) along the south Atlantic Coast of the United States. By William W. Anderson. May 1970, iii + 24 pp., 15 figs., 12 tables. 606. Annotated references on the Pacific saury, Colol- abis saira. By Steven E. Hughes. June 1970, iii -|- 12 pp. 607. Studies on continuous transmission frequency modulated sonar. Edited by Frank J. Hester. June 1970, iii + 26 pp. 1st paper. Sonar target classification experiments with a continuous- transmission Doppler sonar, by Frank J. Hester, pp. 1-20, 14 figs., 4 tables; 2d paper. Acoustic target strength of several species of fish, by H. W. Volberg, pp. 21-26, 10 figs. 608. Preliminary designs of traveling screens to col- lect juvenile fish. July 1970, v -f 15 pp. 1st paper. Traveling screens for collection of juvenile Continued on inside back cover. .z^- .^0 ATMOSP^,. mm U.S. DEPARTMENT OF COMMERCE Maurice H. Stans, Secretary NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION Robert M. White, Administrator NATIONAL MARINE FISHERIES SERVICE Philip M. Roedel, Director NOAA Technical Report NMFS SSRF-639 A Hydrographic Survey of the Galveston Bay System, Texas, 1963-66 E. J. PULLEN, W. L. TRENT, AND G. B. ADAMS ^ Marine Biological Laboratory LIBRARY OCT 14 1992 I Woods Hole, Mass I J SEAHLE, WA. October 1971 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington. D.C., 20402 - Price 30 cents Stock number 0320-0024 CONTENTS Page Introduction 1 Study area and methods 2 Analysis and presentation of data 3 Water temperature 3 Comparison between habitats 3 Comparison between years 4 Four-year average 4 SaHnity 5 Comparison between habitats 5 Compai'ison between bay areas 5 Comparison between years 6 Relation to river discharge 6 Salinity isopleths 6 Dissolved organic nitrogen 7 Compai-ison between habitats 7 Comparison between bay areas 8 Comparison between years 8 Relation to river discharge 8 Total phosphorus 9 Comparison between habitats 9 Comparison between bay areas 9 Comparison between years 10 Relation to river discharge 10 Relation to nitrogen 10 Dissolved oxygen 10 Comparison between habitats 10 Comparison between bay areas 11 Comparison between years 11 Discussion 11 Literature cited 12 111 FIGURES No. Page 1. The Galveston Bay system and associated watersheds 2 2. Study areas of the Galveston Bay system showing bay areas, habitats, and locations of sampling stations 3 3. Average water temperature by date and year and the monthly mean, standard deviation, and range of temperatures in the Galveston Bay system for all years combined, 1963-66 4 4. Mean bottom salinity by date and habitat within each bay area of the Galveston Bay system, 1963-66 5 5. Mean values of bottom salinity by date, habitat, and year in the Galveston Bay system. 1963-66 6 6. Maximum, minimum, and mean salinity compared with stream flow in the Galveston Bay system, Texas, 1963-66 6 7. Annual isohalmes and the average isohaline based on 4 years of data, 1963-66 7 8. Mean concentrations of dissolved organic nitrogen by date and habitat within each bay area of the Galveston Bay system, 1964-66 7 9. Isopleths (annual average) for dissolved organic nitrogen in the Galveston Bay system, 1964-65 8 10. Mean values of dissolved organic nitrogen by date, habitat, and year in the Galveston Bay system, 1964-66 8 11. Mean concentrations of total phosphorus by date and habitat within each bay area of the Galveston Bay system, 1964-66 9 12. Isopleths (annual average) for total phosphorus in the Galveston Bay system, 1964-65 9 13. Mean values of total phosphorus by date, habitat, and year m the Galveston Bay system, 1964-66 10 14. Mean concentrations of dissolved oxygen by date and habitat within each bay area of the Galveston Bay system, 1964-66 11 15. Mean values of dissolved oxygen by date, habitat, and year m the Galveston Bay system, 1964-66 11 IV TABLES No. Page 1. Sampling frequency, type of information obtained, and the number of samples taken by habitat and year in the Galveston Bay system, 1963-66 3 2. Comparisons of annual mean bottom water temperatures between habitats within each bay area in the Galveston Bay system, 1963-66 4 3. Comparisons of annual mean bottom salinities between habitats within each bay area in the Galveston Bay system, 1963-66 5 4. Comparisons of annual mean bottom salinities between bay areas within each habitat in the Galveston Bay system, 1963-66 5 5. Comparisons of annual mean concentrations of dissolved organic nitrogen between habitats within each bay area in the Galveston Bay system, 1964-66 7 6. Comparisons of annual mean concentrations of dissolved organic nitrogen between bay areas within each habitat in the Galveston Bay system, 1964-66 8 7. Correlation coefficients (r) between average weekly stream flow and concentrations of dissolved organic nitrogen, 1964-66 8 8. Comparisons of annual mean concentrations of total phosphorus between habitats within each bay area in the Galveston Bay system, 1964-66 9 9. Comparisons of annual mean concentrations of total phosphorus between bay areas within each habitat in the Galveston Bay system, 1964-66 9 10. Correlation coefficients (r) between average weekly stream flow and concentrations of total phosphorus, 1964-66 10 11. Comparisons of annual mean concentrations of dissolved oxygen (ml/liter) between habitats within bay area in the Galveston Bay system, 1964-66 10 12. Comparisons of annual mean concentrations of dissolved oxygen (ml/liter) between bay areas within each habitat in the Galveston Bay system, 1964-66 11 A Hydrographic Survey of the Galveston Bay System, Texas, 1963-66 ^ By E. J. PULLEN, W. L. TRENT, and G. B. ADAMS National Marine Fisheries Service Biological Laboratory Galveston, Texas 77550 ABSTRACT Water temperature and salinity data, taken during 1963-66, and dissolved organic nitrogen, total phosphorus, and dissolved oxygen data taken during 1964-66 from Galveston Bay, Texas were analyzed by area and habitat (depth strata). Temperatures ranged from 0.4° C to 36.0° C during the study and averaged slightly higher in the peripheral than the open-water or channel habitat. Between years, water temperature averages varied as much as 7°C between coldest months, and 3°C between warmest months. Salinities ranged from 0.1to36.6%o and increased from the peripheral to the channel habitats. Gradients of increasing salinities occurred from east to west and north to south in the system. Salinities decreased from 1963 to 1966 with the smallest difference between years occurring in March and April and the greatest difference between years in May and June. Minimum salinities always occurred during periods of high stream discharge in the winter and spring and maximum salinities during periods of low stream discharge in the late summer and fall. Dissolved organic nitrogen concentrations ranged from 1 to 300 jug at /liter. Nitrogen concentrations decreased from the upper to the lower bays. Nitrogen values were similar seasonally and between years. High river flow was correlated with an increase of nitrogen in the lower bay areas. Total phosphorus concentrations ranged from 0.1 to 47.5 ^ig at /liter. Phosphorus concentrations diminished from upper to lower bays, and from west to east in the system. Seasonal concentrations of phosphorus were similar from 1964 through the spring of 1966. In June 1966, concentrations increased, reaching an all years' maximum in the fall. River discharge was not correlated to phosphorus concentrations, although nitrogen and phosphorus values were positively correlated. Dissolved oxygen concentrations ranged from 0.2 to 13.6 ml/liter. Lowest oxygen concentrations were in the channels and highest and similar concentrations were in the peripheral and open-water habitats. Oxygen values were inversely correlated with water temperatures. INTRODUCTION in many estuaries and lagoons along the U.S. coast. Alterations caused by the construction Degradation or destruction of estuarine of channels, dikes, and bulkheads; the dis- habitats by municipal, industrial, agricultural, charge, of pollutants; and the reduction of and recreational expansion is a major problem freshwater flows change the hydrological char- I Contrihution No. 31 5, National Marine lislUTJus Serv ice liiolO):ical laboratory, (lalveston. Texas 77550. acteristics of estuaries. Evaluation of changes detrimental to estuarine biota is aided by infor- mation on the hydrological conditions existing before the alterations. The hydrology and biology of the Galveston Bay system are being studied or have been studied by various State, Federal, and private agencies. Studies contributing significant infor- mation on the hydrology of this system include those by Reid (1955, 1956, and 1957); Cham- bers and Sparks (1959); Arnold, Wheeler, and Baxter (1960); Zein-Eldin (1961); Chin (1961); Odum et al. (1963); Pullen (1969); Baldauf (1970); and Copeland and Fruh (1970). Gloyna and Molina (1964), using data from State, Federal, and private agencies, compiled a report for the Texas Water Pollution Control Board on the water c(uality of the bay system. The observations analyzed and reported in the present paper and all hydrological data col- lected by personnel of the Estuarine Program, National Marine Fisheries Service, Galveston, Texas, from 1958 through 1967 were pub- lished by Pullen and Trent (1969). The objectives of our study were to: (1) summarize bottom temperature, salinity, dis- solved organic nitrogen, total phosphorus, and dissolved oxygen data in relation to three habitats and five bay areas, and (2) determine the temporal and spatial distributions and ranges of these parameters and some of the relations and mechanisms affecting their distri- butions. STUDY AREA AND METHODS The Galveston Bay system, located on the upper Texas coast, has a water area of about 1,360 km^ (Figure 1). Water is exchanged with the Gulf of Mexico through three tidal passes. About 85% of this exchange is through Bolivar Roads Tidal Pass, about 14% through San Luis Pass, and about 1% through Rollover Pass (U.S. Corps of Engineers, personal communication). Two major navigation channels— the Houston Ship Channel, connecting Houston to the Gulf of Mexico, and the Gulf Intracoastal Waterway, running southwesterly through the marsh areas of the lower bays— pass through the system. The tidal range is 0.5 m in the lower portion of the system and 0.3 m in the upper (U.S. WEST BM "^AN LUIS PASS BOLIVAR ROADS TIDAL PASS Figure 1. The Galveston Bay system and associated watersheds. Department of Commerce, Coast and Geodetic Survey, 1969). Winds, as reported by U.S. Weather Bureau data for Galveston, Texas, are predominantly southeasterly in the sumrner and northerly in the winter. Thirty-seven years (1931-67) of data collected by the U.S. Weather Bureau in Galveston show the mean annual rainfall to be 113 cm and the mean air temperature 20.8° C. Most freshwater inflow to the bay system is from the Trinity and San Jacinto watersheds (Figure 1). Stream discharge data for the Trin- ity and San Jacinto watersheds were obtained from the U.S. Geological Survey. Annual stream flows averaged about 7 billion m^ for the Trinity and about 2 billion m^ for the San Jacinto watersheds. The drainage area of the Trinity watershed is 46,540 km^ and that of the San Jacinto watershed is 10,298 km^. Average annual precipitatipn over the water- sheds generally varies from 89 cm at Dallas to 114 cm at Houston (U.S. Bureau of Reclama- tion, 1964). The bay system was divided into the fol- lowing geographic areas for this study: Lower Galveston, mid-Galveston, Upper Galveston, East, and Trinity Bays (Figures 1 and 2). West Bay was not included in this study. The bay areas were further divided into peripheral, open-water, and channel habitats (Figure 2). Station numbers and locations indicated in Figure 2 are those reported by Pullen and Trent (1969). The peripheral habi- tat was in water depths less than 1.2 m; the open-water habitat was in depths of 1.2 to 3.0 m; and the channel habitat was in depths Figure 2. Study areas of the Galveston Bay system showing bay areas, habitats, and locations of sampling stations. greater than 3 m. Habitat depths (mean low water) were determined from the U.S. Coast and Geodetic Survey Nautical Chart No. 1282. Sampling frequency and the number of sampling stations in each habitat and bay area varied from year to year, and frequency also varied within each year except 1963 (Table 1). During a collection period, samples were taken at all stations within a 2- or 3-day interval except when adverse weather interrupted sampling. All sampling was in daylight hours. Water samples or in situ measurements were taken from the lower 0.3 m of the water column to determine temperature, salinity, dis- solved organic nitrogen, total phosphorus and dissolved oxygen. The techniques for meas- uring each parameter are described by Pullen and Trent (1969). ANALYSIS AND PRESENTATION OF DATA Data for each parameter were independently related to habitat and bay area within each year and are presented in statistical and/or graphical form. Paired-comparison ^tests or two-way analyses of variance were used for all comparisons between habitats or bay areas. Bay areas or habitats served as treatments and dates of sampling as blocks. Mean values of a given variable determined by combining data from all stations within a particular habitat and bay area for each collection were used as observations for the statistical comparisons. WATER TEMPERATURE Water temperatures during this 4-year survey ranged from 0.4° C to 36.0° C. The smallest annual range was 23.4° C (9.0° C to 32.4° C) in 1965 and the largest was 33.6° C (0.4° C to 34.0° C) in 1963. Comparison Between Habitats Comparisons of temperatures by habitat within bay areas are shown in Table 2. Average Table 1.— Sampling frequency, type of information obtained, and the number of samples taken by habitat and year in the Galveston Bay system, 1963-66. ^aniplK.g /requ Weekly montKly Monthly 1963 Peripheral 28 Ojje" water ZZ Channel 6 1964 Peripheral 11 Open water ZZ Channel 9 1965 Peripheral 15 Open water 16 Channel 5 1966 Peripheral 17 Open water 17 Channel 6 rempcrature SalMii Organic y '.■ 1966 9.5 IJ. 1 22.6 2. SO 181. STSO Lowi- r GaKcsio.1 1963 U.*) ^4.8 29 . \ 2. 46 35.46« J964 d\.4 £4 8 28.8 2. 26 39. 48*« 1965 15. 7 Zl. 1 23. 7 2. SS 56.93** 1966 12.7 18.9 25.8 2. 50 144.6 30* - No data- M(.e lrv«i -- 1%. PCaiPHCRAL ■ OPEN W»TEIt CHakHCL •"ri'gSJ E45T BAY 1964 EAST BAY 4(,r THINlTT B*V TRINITY BAY ,0~ UPPER GALVESTON BAY UPPER GALVESTON BAY »t ^ .^ ^ — - T40^ HID-GALVESTON BAY MIO-GALVESTON BAY g 4oC LOWER GALVESTON BAY LOWER GALVESTON BAY __ ^«Li965 EAST BAY ■966 EAST BAY O«0- TRINITY BAY -~^ TRiNiTt bay 5»o- UPPER GALVESTON BAY - — . 40- MIO-GALVESTON BAY -_- — MID-GALVESTON BAY 40- LOWER GALVESTON BAY LOWER GALVESTON BAY JAN. MAR MAY JUL SEP i» IS NOV JAN MAR MAY JUL SEP NOV Figure 4. Mean bottom salinity by date and habitat within each bay area of the Galveston Bay system, 1963-66. ences in salinity between habitats were highly significant except for East Bay in 1965. The greatest difference between habitats was in the three western bay areas, which are under the direct influence of the Houston Ship Channel. Comparison Between Bay Areas Salinities were significantly different be- tween bay areas within each habitat during each year (Table 4). SaUnities were lowest in Trinity Bay and highest in Lower Galveston Bay. A progressive increase in salinity from the upper bays to the Gulf was evident in all habitats each year, with the exception of East Table 4.— Comparisons of annual mean bottom salini- ties between bay areas within each habitat in the Galveston Bay system, 1963-66 Calvesi Mid- L Galveston Gai of freedom 1963 1964 1965 1966 1963 17.9 16-4 16.7 10- 5 19.4 19ti4 iH.5 1965 17.5 1966 10.5 1963 22 9 1964 23.0 1965 15 9 1966 16.9 13.0 12.6 7-9 5.4 15.3 15- 7 11.8 7-3 18. I 17.9 15.5 10.9 18.8 19.5 13.9 11.6 25.0 24 I 19.0 20. 2 15 4 9.8 19-9 19-9 17 8 12. 5 27.0 26.0 21 .7 22. 8 22.7 21.4 16- 7 12.5 24.9 24.6 23.5 18. 7 29.4 28.8 23.6 25, 8 4. 92 4. 52 4. I 12 4. 96 4. 84 4. 52 4, 60 4. 104 3. 69 3. 39 3, 72 3. 75 29.8** 19. 2** 63. 5M 38. O** 35. 5** 34. !•• 39. 9»* 78. I** 25.4*» B.6** 15. O** 32. 9** ** Significance level = 1%. Bay. Salinities in tiie peripheral and open-water habitats of East Bay were similar to those in mid-Galveston and Upper Galveston Bays, whereas salinities in the Intracoastal Waterway (channel habitat) were lower than those in the Houston Ship Channel. This anomalous situa- tion in East Bay is probably related to drainage of a large marsh adjacent to the Intracoastal Waterway and to reduced saltwater intrusion in the waterway as compared with the Ship Chan- nel. Comparison Between Years For between-year comparisons, salinity data for all bay areas were combined by habitat and by year and plotted by date for the bay system (Figure 5). The data indicated a general decrease in salinity in ail habitats from 1963 to 1966. The smallest difference in salinity be- 1963 1969 I96« r966 ^,,^^^-'T^~j^ -T^ - ~ - ^ — peripheral"^ _„»i=^ -^J.— ■■"..y^.^r— — "~-_'-' OPEN WATER ^~^ ^^^'^^ CHANNEL 10 2C 10 20 10 20 10 ro 10 20 10 20 lO 20 10 20 10 20 10 20 10 20 10 20 JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Figure 5. Mean values of bottom salinity by date, iiabitat and year in the Galveston Bay system. 1963-66. tween years (about 4%o) was in March and April, and the greatest difference between years (about 20%o) was in May and June. Differences of 10%3 or greater between years were observed from May to September in the peripheral and open-water habitats. The chan- nel habitat, which generally had the least sa- linity variation between years, had differences of 10%o or greater from May through June. Seasonal trends varied between years in all habitats, although minimum salinities always occurred during the winter and spring and maximum salinities always occurred during the late summer and fall. Relation to River Discharge The relation between river flow and max- imum, minimum, and mean salinity in the bay system is shown in Figure 6. The Trinity and San Jacinto watersheds discharged between 2.5 Figure 6. Maximum, minimum, and mean salinity compared with stream flow in the Galveston Bay system, Texas, 1963-66. billion m^ of water in 1963 and 10.1 billion m^ in 1966. Of the yearly totals, the Trinity watershed contributed 75% or more of the total discharge each year. Salinities were inversely correlated with stream discharge (r = -0.60, d.f. = 96 for the Trinity and r = -0.37, d.f. = 96 for the San Jacinto watersheds) with the upper bay areas responding quickly to changes in stream flow (Figures 4 and 6). The maximum water discharge during the 4 years occurred in 1966, initiating a marked reduction in salinities in the peripheral and open-water habitat of all bay areas (Figures 4 and 5). Salinities in the channel habitat are primarily controlled by tidal waters from the Gulf and, thus, were less affected by freshwater inflow than those in the other habitats. Salinity Isopleths Annual isohalines for the bay system, and an isohaline constructed from the 4 years of data, are shown in Figure 7. Average salinities of 10%jor greater were recorded near the Trinity River in 1963-64, whereas the 10% isohaline shifted westward toward Upper Galveston Bay in 1965 with increased freshwater inflow. In 1966, saUnities averaged below 10%oin Trinity Bay. Lower Galveston Bay, which is adjacent to the Gulf, averaged 25%o or greater in 1963-64, but not in 1965-66. In general, the system changed from a high-salinity regime brought on by a drought period in 1963-64 to a low-salinity regime in 1965-66 as a result of high rainfall and river discharge. The areal distribution of average salinities for the 4-year period showed that salinities in- creased from east to west and north to south in the system. The configuration of the isohalines ^f^~^^=5:^A 1963-1966 ■"" ^ SAL (%o) Figure 7. Annual isohalines and the average isohaline based on 4 years of data, 1963-66. in the western portion of the system em- phasized the importance of Bolivar Roads Tidal Pass and the Houston Ship Channel as an ex- change mechanism for bay and Gulf waters. Rollover Pass had little influence on the sys- tem, except in East Bay in the immediate vicinity of the pass. DISSOLVED ORGANIC NITROGEN Concentrations of dissolved organic nitrogen in the Galveston Bay system varied from 1 /Lig at/liter to 300 /xg at/liter. Both extremes were recorded in Upper Galveston Bay. The range in values in the bay system for each year that nitrogen was sampled were 10 to 251 fxg at/liter in 1964, 1 to 300 ^lg at/liter in 1965, and 6 to 200 jUg at/liter in 1966. Comparison Between Habitats Concentrations of nitrogen differed signif- icantly between habitats in Lower Galveston, Upper Galveston, and East Bays in 1965 and in Lower Galveston Bay in 1966 (Table 5, Figure 8). The greatest concentration of nitrogen was in the channel habitat in Upper Galveston and East Bays in 1965, whereas the peripheral habitat of Lower Galveston Bay had the greatest concentration of nitrogen in 1965 and 1966. Table 5.— Comparisons of annual mean concentrations of dissolved organic nitrogen between habitats within each bay area in the Galveston Bay system, 1964-66. Bay area Habitats compa nitrogen \ Upper Galveston Mid- Galxeston Lower Galveston 1964 1965 1966 1^64 1965 1966 1964 1965 1966 1964 1965 1966 1964 1965 1966 2, IS 2. 50 0.07 34.04** 106 129 24 2. IS 2. 40 23 2. 18 2. 38 0. 18 1.71 0,83 1.82 0.92 4. 16** 0.62 0.B7 0.64 0.55 6.55** ** Significance level = UPPER GALVESTON BAY MI0-GALVE5TON BAY Figure 8. Mean concentrations of dissolved organic nitrogen by date and habitat within each bay area of the Galveston Bay system, 1964-66. Comparison Between Bay Areas Differences in nitrogen concentration be- tween bay areas in each habitat were highly significant (Table 6). Concentrations of nitro- gen were highest in all habitats of Upper and mid-Galveston Bays except in 1965 when the concentrations in the channel habitat of East Bay exceeded that in mid-Galveston Bay. Table 6.— Comparisons of annual mean concentrations of dissolved organic nitrogen between bay areas within each habitat in the Galveston Bay system, 1964-66. Year Bay areas Tipared and mean hl rogen values Degrees of freedom Habitat East Trim y Uppe Galvea ton Mid- Galves Lower on Galvesto F value l^g at/ ^ Peripheral 1964 62 89 78 45 4, 36 6. 74** 1965 38 84 62 41 4, 104 jz.oa**- 1966 44 90 66 47 4, 100 I5-57** Open water 1964 53 - 64 39 3. 27 1 1.54«« 1965 39 - 51 30 3. 27 18-3I«* 1966 42 94 73 40 4. 80 1 1 .9n=>* Channel 1964 - 106 63 40 3, 24 is-g?-** 1965 - 142 55 27 3. 42 80, 14*^ ** Significa ce leve ^ \%. . No data. Areal distributions of nitrogen concentration in the bay system are shown in Figure 9. An isopleth was not drawn for 1966 because nitro- gen was sampled at only 16 stations. The greatest concentration of nitrogen was in the Houston Ship Channel, and concentrations decreased from Upper Galveston to Lower Galveston Bay. The second major source of nitrogen was the Intracoastal Waterway where concentrations decreased from the eastern to the western part of East Bay. The isopleths also indicate the relative contribution of nitrogen ORGANIC NITROGEN (/iG AT, /L) Figure 9. Isopleths (annual average) for dissolved organic nitrogen in the Galveston Bay system, 1964-65. from the creeks snA bayous. The influence of Gulf waters low in nitrogen was apparent in Lower Galveston and East Bays. Comparison Between Years In general, nitrogen values were similar be- tween years within each habitat of the Galveston Bay system (Figure 10). Greatest variations between years in the peripheral and open-water habitats were in the spring and fall, whereas the variations between years in the channel were erratic. to 20 10 20 10 20 10,20 10 20 10 20 10 20 10 20 10 20 10 20 10 20 10 20 JAN Ffe MAR APR MflV JUN JUL AUG SEP OCT NOV DEC Figure 10. Mean values of dissolved organic nitrogen by date, habitat, and year in the Galveston Bay system, 1964-66. Relation to River Discharge Nitrogen levels in the lower bays were more closely correlated with river discharge from the Trinity and San Jacinto watersheds than those in the upper bays (Table 7). This may be related to a rapid transport of upper bay water high in nitrogen content into the lower bays during the periods of high river flow. Table 7.— Correlation coefficients (r) between average weekly stream flow and concentrations of dissolved organic nitrogen, 1964-66. Nitrogen versus Trimly discharge Nitrogen ver ^^^^ ^"""^^ Peripheral Open wai Channel Peripheral Open v East 0 37C* d._f. 67 Trimiy -0 06 Upper Galveston -0.29* -0. 11 0,27 -0. 14 d, ( 67 24 32 58 Mid- Galvesloii 0,05 0, 35»« -0,09 0.09 d ( 67 67 29 57 Lower Galveston 0,27* 0,43«« 0. 18 0, 36 d.i, 67 iignidtance le\ el = h%. > Signilicance level = 1 TOTAL PHOSPHORUS Total phosphorus concentrations in the Galveston Bay system during 1966 varied from 0.1 fig at/liter in East Bay to 47.5 jug at/hter in Upper Galveston Bay. The lowest and highest values respectively were 0.7 and 13.7 /jg at/liter in 1964, and 0.3 and 17.1 ;ug at/liter in 1965. Comparison Between Habitats concentration of phosphorus in the open water than in the other habitats in 1964 and 1965, whereas, in 1966, phosphorus concentrations were greater in the peripheral than in the open-water habitat (samples were not taken in the channel). Mid-Galveston Bay had a greater concentration of phosphorus in the open-water than in the peripheral habitat in 1966. Comparison Between Bay Areas Difference in phosphorus concentrations be- tween habitats in all bay areas except East and mid-Galveston Bays were not significant (Table 8, Figure 11). In East Bay, there was a greater Table 8.— Comparisons of annual mean concentrations of total phosphorus between habitats within each bay area in the Galveston Bay system, 1964-66. Bay Year Habitats lumpareiJ a phosphorus vain J mean Degrtei of freedom Test value area Peripheral Open wattr Channel F 1 East 1964 Z. 18 .ga./hter- 2.75 i,84 1965 1.92 Z. 31 1. 30 !966 1.91 I, 39 Tr.mty 1964 6.60 7 08 - 1965 5.64 5 50 - 1966 7.06 7,49 - Upper Galveston 1964 10. 10 _ 10. 19 1965 7.62 - 8- 30 1966 14.47 15.04 - Mid- Galvcston 1964 9,22 8,28 8 05 1965 7 06 6.85 6.47 1966 1 1.90 14 SZ - Lower Calv.sion 1964 3,61 3 57 i 09 1965 4 04 4 03 3,51 1966 7 16 8 10 - h 73?* 22, 71** ♦ Significance level = 5%. •* Significance level = 1%. TniNlTT BAY UPPER GALVESTON BAY MID,GAt,VESTON BAY LOITER GALVESTON BAY Figure 11. Mean concentrations of total phosphorus by date and habitat within each bay area of the Galveston Bay system, 1964-66. Each year concentrations of phosphorus varied significantly between bay areas within each habitat (Table 9). Greatest concentrations were in Upper and mid-Galveston Bays and lowest concentrations were in East Bay. In 1964 and 1965 concentrations of phosphorus decreased from north to south and from west to east in the bay system (Figure 12). Table 9.— Comparisons of annual mean concentrations of total phosphorus between bay areas within each habitat in the Galveston Bay system, 1964-66. Habitat Year East Trinity Upper Mid- Lower of F 2,07 0 78 Galveston Galvcsto.. Galveston Ireedom value - tig al/lite 1.05 Peripheral 1964 Z. 19 6. 40 9.88 9.33 3,61 4. 32 47.34** 1965 1.95 5 83 7. 27 6.91 4.22 4. 100 49.66** 0.09 111 1966 1.91 6-90 13,52 11.61 6,96 4. iOO 37.010* 0.91 Open water 1964 2 79 7.08 - 8.52 3.69 3. 27 128.45** 1,71 1965 2.29 5.61 - 6.55 4. 18 3. 69 60.79S* 0,67 5 68** 1966 1 , 41 7,52 15 04 15. 18 9. 19 4. 68 46- 38*-* Channel 1964 1. 51 - 10. 30 8. 19 3, 12 3. 18 4 3.41** 0 77 196S 1. 21 - 8.66 6.52 3,46 3. 51 18-42*0 0 Q5 > Sign.Ii, , No dat; TOTAL PHOSPHORUS (/iiG AT/L ) Figure 12. Isopleths (annual average)for total phos- phorus in the Galveston Bay system. 1964-65. Comparison Between Years Relation to Nitrogen Mean concentrations of phosphorus between years were similar in 1964, 1965, and during the first half of 1966 (Figure 13). Beginning in June 1966, phosphorus concentrations increased markedly from a level of about 5 ng at/liter in the habitats sampled and reached an all years' maximum of about 20 ng at/liter during the fall. Values remained above average (about 5pg at/liter) the remainder of the year. rO 20 10 20 10 20 jiN fEB MaH 10 20 10 20 10 20 10 20 lO 20 APR Mar JUN JUL auG 10 20 ;0 20 10 20 SEP OCT NOV 10 20 DEC Figure 13. Mean values of total phosphorus by date, habitat, and year in the Galveston Bay system, 1964-66. Relation to River Discharge River discharge from the Trinity or San Jacinto watersheds was not closely correlated with phosphorus levels in any of the habitats or bay areas (Table 10), although phosphorus concentrations in the system reached the greatest levels following the period of greatest stream flow in 1966 (Figures 6 and 11). Table 10.— Correlation coefficients (r) between average weekly stream flow and concentrations of total phos- phorus, 1964-66. el Peripheral Tr.n.ty a 1. Upper Galveston d. f Mid- Galveston d (. Lower CaUeston 0 IS -0.2fce 0-20 -0 10 0 2B 0.01 Phosphorus and nitrogen values were pos- itively correlated each year (r = 0.43, d.f. = 328 in 1964; r = 0.39, d.f. = 757 in 1965; and r = 0.36, d.f.= 382 in 1966). DISSOLVED OXYGEN Dissolved oxygen levels in the system varied from a minimum of 0.2 ml /liter in East Bay to a maximum of 13.6 ml/liter in Upper Galveston Bay. Annual low and high values, respectively, were 2.4 and 13.6 ml /liter in 1964, 0.9 and 13.4 ml/liter in 1965, and 0.2 and 10.8 ml/liter in 1966. Comparison Between Habitats Within each bay area and year, dissolved oxygen concentrations were usually lowest in the channel and highest in the peripheral and open-water habitats (Table 11, Figure 14). The greatest variations in oxygen concentrations between habitats occurred in Upper Galveston, mid-Galveston, and East Bays. Table 11.— Comparisons of annual mean concentrations of dissolved oxygen (ml/liter) between habitats within bay area in the Galveston Bay system, 1964-66. Habitats compared and mean Degrees oxygen > S.gniricance level = ^%. *♦ Significance level = i% area Peripheral Open water Channel lre<^dom F ' 1964 5 8 ml/hter 5.0 2. 18 9.34«» East 5 7 1965 6 0 6.0 4 6 2. 42 37 3I*» 1966 5 9 fa 2 - 28 i 79«» Trinity 1964 5 5 5 7 - 9 i. 16 r965 b i 6. I - 29 0 85 r966 fe.O 6. 1 - 24 0.29 Upper Galveston 1964 7 0 . 4 3 8 3 03* 1965 6 5 - 4 4 15 3-9l*» 1966 S 0 4 9 - 25 0-42 M id- eal veslon 1964 7 3 5 6 4 7 2, 18 15 8I*« 1965 6.4 5.7 4 9 2. 32 6 86** 1966 6.4 5 7 - 24 2 30 Lower Galveston 1964 4 9 5 5 5 2 2. 18 3 13 1965 S 9 S 8 5 6 2. 24 0-65 1966 6 Z fa Z - 26 0 14 • Significan ce level = 5%. *• S.gnU.can ce level = 1%. - No data 10 DISSOLVED OXYGEN TRINITY BAY UPPER GALVESTON BAY MID-GALVESTON BAY LOWER GALVESTON BAT reniPHERAL - OPEN WATER - CHANNEL Figure 14. Mean concentrations of dissolved oxygen by date and habitat within each bay area of the Galveston Bay system, 1964-66. Comparison Between Bay Areas Comparisons of dissolved oxygen values be- tween bay areas are shown in Table 12. In the peripheral habitat, oxygen values were gen- erally higher in mid-Galveston Bay than in the other bays. In the channel, however, oxygen values were lowest in Upper Galveston Bay and increased toward Lower Galveston Bay. Dis- solved oxygen concentrations, as shown by mean values, were relatively stable throughout the open-water habitat in 1964-65 but were depressed in Upper Galveston Bay in 1966. Table 12.— Comparisons of annual mean concentrations of dissolved oxygen (ml/liter) between bay areas within each habitat in the Galveston Bay system, 1964-66. Year Bay areas compared and meanoxyge n values Degrees of Habitat East Trinity Upper Mid- Lower F Galveston Galveston Galveston Ir eedom vJuc Periphera 1%4 5.8 5,5 6-9 7,3 4-9 36 4 73»* 1965 6 1 6.4 5 7 6 6 5.9 86 2.05 1966 5.8 6.0 5.2 6.6 6.2 104 6.27** Open wate r 1%4 5-7 5.7 - 5.6 5.5 0.27 1965 5. 9 6-2 - 5.9 5-9 0,88 1966 6.0 5 8 4 8 5 5 5 9 2.97*« Channel 1964 5- 1 4,3 4.3 5.3 5.30»» 1965 4-6 - 4.2 5.2 5, 3 1.59 Comparison Between Years Seasonal trends in the concentrations of oxygen were similar between years (Figure 15). Oxygen values were maximum during the 5 10- 5 5- I96< - 1965 [966- OPEN WATER 10 20 K) 20 10 20 10 20 10 20 10 20 10 20 10 20 10 20 10 20 10 20 10 20 JAN FEB Mflfl APR MAY JUN JUL AUG SEP OCT NOV DEC Figure 15. Mean values of dissolved oxygen by date, habitat, and year in the Galveston Bay system, 1964-66. winter, decreased through the spring and attained an annual low in the summer. Oxygen levels then increased during the fall and attained an annual maximum again during the following winter. This trend was inversely correlated to temperatures as indicated by r-values of -0.44, d.f. = 343 in 1964; -0.23, d.f. = 686 in 1965; and -0.52, d.f. = 409 in 1966. The channel habitat had greatest variations in oxygen concentration between years. DISCUSSION Several major alterations that are expected to affect the hydrography of the Galveston Bay system are contemplated or under construc- tion. An electric generating plant is being con- structed on Cedar Bayou, which empties into Upper Galveston Bay, by the Houston Lighting and Power Company (Figure 1). A maximum of about 63.7 m^/sec of water will be taken into the intake canal located 14.5 km up Cedar Bayou, warmed about 5° C, and discharged into Trinity Bay through an excavated channel. This amount of water flow is about 24% of the average annual flow from the Trinity and San Jacinto watersheds combined. The water being drawn from Upper Galveston Bay through the mouth of Cedar Bayou will flow predom- inantly upstream. Passage of large volumes of water through the generating plant is expected to increase temperature, salinity, dissolved organic nitrogen, and total phosphorus in some areas of Trinity Bay. The proposed Texas Basin Project is one of many plans to develop water resources of Texas (Diener, 1964; Chapman, 1966). Reser- voirs would supply water to a trans-Texas canal which would intercept tributary discharge to 11 all coastal marshes. Anticipated water demands not related directly to the project, combined with project diversions, would reduce by one- half the average annual freshwater flow of 31.7 X lO" m"^ now reaching Texas estuaries. Fresh- water flow into the Galveston Bay system would be reduced by about one-third. Even more dramatically, Moore (1968) stated "It has been roughly computed that annual freshwater needs from the developed rivers for bays and estuaries will amount to 2.45 million acre-feet (3 X lO" m*^) annually, while the annual Gulf water needs through new tidal inlets will amount to 33.4 million acre-feet (40.7 x 10^ m^)." This plan, if implemented, will cause salinities in the Galveston Bay system to increase. If freshwater inflows are reduced without an increased flow of Gulf water into the bay system, we anticipate nitrogen and phosphorus concentrations to increase. If flow of Gulf water into the bay system increases, we anticipate nitrogen and phosphorus levels to decrease. Hurricane protection levees are being built around the Galveston Bay system and tidal exchange structures for the tidal passes are being designed and planned by the U.S. Corps of Engineers. These structures are expected to reduce tidal exchange, thus affecting the normal circulation patterns in the system. Salinities would probably be reduced under the present stream flow conditions, whereas nitro- gen and phosphorus levels would probably increase owing to a reduction of water exchange to the system. We would expect the large amount of nutrients that would accu- mulate to cause dissolved oxygen depletion of the water at times. The quantity of industrial and domestic effluents entering the Galveston Bay system is about 1.8 million m"^ per day (R.A. Diener, NMFS, unpublished data). Since human pop- ulations are increasing rapidly in areas adjacent to the Galveston Bay system, we expect the domestic and industrial pollution load entering the system to increase in a similar manner for a long period of time. Nitrogen and phosphorus levels are already high in some parts of the bay system and are expected to reach much higher levels in the near future. Various modifications to the bay system can have opposing effects on particular hydro- graphic variables, as indicated in the examples previously discussed. Some modifications could be planned which allow the maintenance of hydrological conditions similar to the natural state. Until more is known about the biology of estuarine animals, modifications of estuaries without maintaining present hydrological conditions involves a great risk of destroying many valuable estuarine resources. LITERATURE CITED ARNOLD, E.L., R.S. WHEELER, and K.N. BAXTER. 1960. Observations on fishes and other biota of East Lagoon, Galveston Island. U.S. Fish Wildl. Serv., Spec. Sci. Rep. Fish. 344, 30 p. BALDAUF, R.J. 1970. A study of selected chemical and biological conditions of the lower Trinity River and upper Trinity Bay. Water Resour. Inst., Tex. A&M Univ., Tech. Rep. 26, 168 p. CHAMBERS, G.V., and A.K. SPARKS. 1959. An ecological survey of the Houston Ship Channel and adjacent bays. Publ. Inst. Mar. Sci., Univ. Tex. 6: 213-250. CHAPMAN, C.R. 1966. The Texas Basins Project. In A sympo- sium on estuarine fisheries, p. 83-92. Amer. Fish. Soc. Spec. Publ. 3. CHIN, E. 1961. A trawl study of an estuarine nursery area in Galveston Bay, with particular reference to penaeid shrimp. Ph.D. Thesis, Univ. Wash., Seattle, 113 p. COPELAND, B.J., and E.G. FRUH. 1970. Ecological studies of Galveston Bay, 1969. Final Report to Texas Water Quality Board (Galveston Bay Study Pro- gram) for Contract lAC (68-69)-408, Inst. Mar. Sci., Univ. Tex., 482 p. 12 DIENER, R.A. 1964. Texas estuaries and water resource development projects. Proc. 19th Annu. Conf., Water for Texas, Nov. 23-24, 1964, Tex. A&M Univ., p. 25-31. GLOYNA, E.F., and J.F. MALINA, JR. 1964. Galveston Bay water quality study- historical and recent data. Report pre- pared for the Texas Water Pollution Control Board, Environmental Health Engineering Laboratories, Univ. Tex., 192 p. REID, O.K. 1955. A summer study of the biology and ecology of East Bay, Texas. Tex. J. Sci. 7: 316-343. 1956. Ecological investigations in a disturbed Texas coastal estuary. Tex. J. Sci. 8: 296-327. 1957. Biologic and hydrographic adjustment in a disturbed Gulf coast estuary. Limnol. Oceanogr. 2: 198-212. MOORE, J.G., JR. 1968. Bays and estuaries and the Texas water plan. Proc. Gulf Caribb. Fish. Inst., 20th Annu. Sess., p. 60-68. ODUM, H. T., R. P. CUZON du REST, R. J. BEYERS, and C. ALLBAUGH. 1963. Diurnal metabolism, total phosphorus, ohle anomaly, and zooplankton diversity of abnormal marine ecosystems of Texas. Publ. Inst. Mar. Sci., Univ. Tex. 9: 404-453. PULLEN, E.J. 1969. Hydrological conditions in Clear Lake, Texas, 1958-66. U.S. Fish Wildl. Serv., Spec. Sci. Rep. Fish. 578, 8 p. PULLEN, E.J., and L. TRENT. 1969. Hydrographic observations from the Galveston Bay system, Texas, 1958-67. U.S. Fish Wildl. Serv., Data Rep. 31, 151 p. U.S. BUREAU OF RECLAMATION, REGION 5, AMARILLO, TEXAS. 1964. Texas basins project, Vol. I., 175 p. U.S. DEPARTMENT OF COMMERCE, COAST AND GEODETIC SURVEY. 1969. Tide tables, high and low water pre- dictions for the East Coast, North, and South America including Greenland. 289 p. U.S. DEPARTMENT OF COMMERCE, WEATHER BUREAU. Local climatological data 1931-67. Galveston, Texas. ZEIN-ELDIN, Z.P. 1961. Plankton pigments in East Lagoon, Galveston, Texas. Trans. Amer. Fish. Soc. 90: 32-41. * GPO 795-108 13 MBL Who/ ^,. Sens, WHseSi^J^ salmon (models I and II), by Daniel W. Bates and John G. Vanderwalker, pp. 1-5, 6 figs., 1 table ; 2d paper. Design and operation of a canti- levered traveling fish screen (model V), by Dan- 620. iel W. Bates, Ernest W. Murphey, and Earl F. Prentice, 10 figs., 1 table. 609. Annotated bibliography of zooplankton sampling devices. By Jack W. Jossi. July 1970, iii + 621. 90 pp. 610. Limnological study of lower Columbia River, 1967-68. By Shirley M. Clark and George R. Snyder. July 1970, iii + 14 pp., 15 figs., 11 tables. 622. 611. Laboratory tests of an electrical barrier for con- trolling predation by northern squawfish. By Galen H. Maxfield, Robert H. Lander, and Charles D. Volz. July 1970, iii -|- 8 pp., 4 figs., 5 tables. 623. 612. The Trade Wind Zone Oceanography Pilot Study. Part VIII: Sea-level meteorological properties and heat exchange processes, July 1963 to June 1965. By Gunter R. Seckel. June 1970, iv -|- 129 pp., 6 figs., 8 tables. 624. 613. Sea-bottom photographs and macrobenthos col- lections from the Continental Shelf off Massa- chusetts. By Roland L. Wigley and Roger B. Theroux. August 1970, iii + 12 pp., 8 figs., 2 625. tables. 614. A sled-mounted suction sampler for benthic or- ganisms. By Donald M. Allen and J. Harold Hudson. August 1970, iii + 5 pp., 5 figs., 1 table. 626. 615. Distribution of fishing effort and catches of skip- jack tuna, Katsuwonus pelamis, in Hawaiian waters, by quarters of the year, 1948-65. By Richard N. Uchida. June 1970, iv -f 37 pp., 6 figs., 22 tables. 629. 616. Effect of quality of the spawning bed on growth and development of pink salmon embryos and alevins. By Ralph A. Wells and William J. Mc- Neil. August 1970, iii + 6 pp., 4 tables. 617. Fur seal investigations, 1968. By NMFS, Ma- rine Mammal Biological Laboratory. December 633. 1970, iii + 69 pp., 68 tables. 618. Spawning areas and abundance of steelhead trout and coho, sockeye, and chum salmon in the Columbia River Basin - past and present. By Leonard A. Fulton. December 1970, iii -|- 37 pp., 636. 6 figs., 11 maps, 9 tables. 619. Macrozooplankton and small nekton in the coastal waters off Vancouver Island (Canada) and Washington, spring and fall of 1963. By Donald S. Day, January 1971, iii -|- 94 pp., 19 figs., 13 tables. The Trade Wind Zone Oceanography Pilot Study. Part IX: The sea-level wind field and wind stress values, July 1963 to June 1965. By Gunter R. Seckel. June 1970, iii -f- 66 pp., 5 figs. Predation by sculpins on fall chinook salmon, Oncorhynchus tshawytscha, fry of hatchery or- igin. By Benjamin G. Patten. February 1971, iii -|- 14 pp., 6 figs., 9 tables. Number and lengths, by season, of fishes caught with an otter trawl near Woods Hole, Massa- chusetts, September 1961 to December 1962. By F. E. Lux and F. E. Nichy. February 1971, iii + 15 pp., 3 figs., 19 tables. Apparent abundance, distribution, and migra- tions of albacore, Thunnus alalunga, on the North Pacific longline grounds. By Brian J. Rothschild and Marian Y. Y. Yong. September 1970, v -f 37 pp., 19 figs., 5 tables. Influence of mechanical processing on the quality and yield of bay scallop meats. By N. B. Webb and F. B. Thomas. April 1971, iii -|- 11 pp., 9 figs., 3 tables. Distribution of salmon and related oceanographic features in the North Pacific Ocean, spring 1968. By Robert R. French, Richard G. Bakkala, Ma- sanao Osako, and Jun Ito. March 1971, iii -|- 22 pp., 19 figs., 3 tables. Commercial fishery and biology of the fresh- water shrimp, Macrobrachium, in the Lower St. Paul River, Liberia, 1952-53. By George C. Mil- ler. February 1971, iii -|- 13 pp., 8 figs., 7 tables. Analysis of the operations of seven Hawaiian skipjack tuna fishing vessels, June-August 1967. By Richard N. Uchida and Ray F. Sumida. March 1971, v -|- 25 pp., 14 figs., 21 tables. For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402 - 35 cents. Blueing of processed crab meat. II. Identifica- tion of some factors involved in the blue discol- oration of canned crab meat (Callinectes sapi- dus). By Melvin E. Waters. May 1971, iii + 7 pp., 1 fig., 3 tables. Oil pollution on Wake Island from the tanker R. C. Stoner. By Reginald M. Gooding. May 1971, iii -I- 12 pp., 8 figs., 2 tables. For sale by the Superintendent of Documents, U.S. Govern- ment Printing Office, Washington, D.C. 20402 - Price 25 cents. UNITED STATES DEPARTMENT OF COWIMERCE NATIONAL OCEANIC & ATMOSPHERIC ADMINISTRATION NATIONAL MARINE FISHERIES SERVICE SCIENTIFIC PUBLICATIONS STAFF BLDG. 67, NAVAL SUPPORT ACTIVITY SEATTLE, WASHINGTON 98115 OFFICIAL BUSINESS POSTAGE AND FEES PAID U.S. DEPARTMENT OF COMMERCE