CONTRIBUTION FOG Monitoring Cruise at the New London Disposal Site July 1987 | Disposal Area Monitoring System DAMOS Se eo - \, pea aw if \ we rae AN ry ‘al \ aN xO \ at EF ah 3 wy \ a a“ Aa oy Ps » 3 Ne \\ P Dente ‘ B - \ ce Contribution 66 March 1990 DOCLAENT LIBiCARY Woods Ho:e Sceanographic Insiiution US Army Corps of Engineers New England Division Te [54 Ds 7 no. &b LANA UU AL O 0301 OOLFSY4L & MONITORING CRUISE AT THE NEW LONDON DISPOSAL SITE JULY 1987 CONTRIBUTION #66 March 1990 Report No. SAIC-88/7511&C66 Submitted to: Regulatory Branch New England Division U.S. Army Corps of Engineers 424 Trapelo Road Waltham, MA 02254-9149 Submitted by: Science Applications International Corporation Admiral's Gate 221 Third Street Newport, RI 02840 (401) 847-4210 US Army Corps of Engineers New England Division abe 1 > — — ‘ ry Sas . 7 of Dette. 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Sate ' ii 7 a ba od > } cw —— = ~ ou i - ° — z ‘ € ali a & § eeu e'letiinbs a , - woe bunt TSS » Me AS iy yy ) ; ; 7 Th 9 Cee Jee. 7 4 ‘ = TABLE OF CONTENTS 1.0 INTRODUCTION 2.0 METHODS Pal Bathymetry and Navigation 252 REMOTS® Sediment Profile Photography Oe Dissolved Oxygen 2 oO Sediment Sampling and Analysis 25 Body Burden Analysis 3.0 RESULTS Bo dt Bathymetry Bok REMOTS® Sediment-Profile Photography Bog} Dissolved Oxygen 3.4 Sediment Characteristics 355 Body Burden Analysis 4.0 DISCUSSION 4.1 Bathymetry 4.2 REMOTS® Sediment Profile Photography Aves Dissolved Oxygen Regime 4.4 Sediment Characteristics 4.5 Body Burden Analysis 5.0 CONCLUSIONS REFERENCES AY ae Ppopai lee dak sogienn bas apie , ¥tqesposoat efitox tnomihe® ooyosaa Sa ae ; is: PO {XO |B dovivasid => aleylena Sas oni iqmet ‘shontbes. _ * . aleylsant cebsud Ybod: ae 7 4 a b- enivedk > | ‘ erpenpdsed & yigetpetodd efitcsd-snamlie: *2 Tones % mpyxo fev foeald i j * Tee » ae 7 5 A , 5 ll = ~~ o ssizalizasoeazsed? Snemibes~ &.€ ‘* : _ v aleylsnA nabuvs yhoe 2.t 7 | - webbeexa ro a bc . Cs yx me E>) (aes I.d : fa" Ie i gz yr sreotodt afltort 2 neni hes 2 poMaut ae me. f — stleet nonyxd beviocetd tab > " ; re ey i4eiretosiad? taenibed 7 ‘ ulaviscs asthivd yheoar BF _ _ if : - > avOTEUioKog 0.2 ee 5 5 é > ® Table Table Table Table Table Table Table Table 3=5 3-6 3-7 4-1 LIST OF TABLES Results of Physical Testing of Sediment Collected at New London, July 1987 Trace Metal and Total Organic Carbon Concentrations in Sediment Collected at New London, July 1987 Results of Statistical Testing for Significant Differences in Chemical Concentrations in Sediment Collected Organochlorine Pesticides and PCB's in Sediment Collected at New London, July 1987 Trace Metal Concentrations in Body Tissues of Leptocheirus Collected at New London, July 1987 Results of Statistical Testing for Significant Differences in Chemical Concentrations in Body Tissues of Leptocheirus Collected at New London, July 1987 PCBs in Body Tissues of Leptocheirus Collected at New London, July 1987 Ecologically Important Dissolved Oxygen Ranges as Determined from Permanently Stratified Low-Oxygen Marine Basins @ SAvsneened nodisd cigars IstoT oa reer yfet .cobaal wet ae betoaliod J Snesiiinei2 “sot priszueT lsoisvetsate Sent bab fii. eo lsaaiaaonoD sealnen? at 7 ~ enighnr dretibee nl 2'a27 bas veer yiut S vasurad ae io 06soumeiT §6yboa ru val #3 bedontioc snoivas77a5ne isten Feel YtuE ,ncbaold wet 2a hesgeliod: faois2ijgaz% - 36 sneaitinpt® xo enisea? -} ati Ybes nt memlidcstaseons>” IabiasiD ni sapnerstt ylet .acbiel 6 26 hetoealios eee te enyaalt AY i Je: bedanlios ScLipiige aa) 3o poureat'( yoos «1 shut ‘Saez yiut nobael vail “5 Bepass aopyxO hbevicazld Inns roges Somtit } St 8 qepyxec-wor! Geitisert2 yiitnedeared mort Ssaltsreteg anions onineM, 3 & a) ¥ 7 aad Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure 38) 3-10. Sail be LIST OF FIGURES Bathymetric survey lanes at the New London Disposal Site. Locations and designations of REMOTS® stations at the New London Disposal Site, July 1987. The location of sediment chemistry and body burden stations at the New London Disposal Site, July USN 7 5 Contoured bathymetric chart of the New London Disposal Site in July 1987. Contoured bathymetric chart of the New London Disposal Site in July 1986. Distribution of dredged material at the New London Disposal Site, July 1987. REMOTS® image from station 200W showing a typical dredged material layer which exceeds the camera prism penetration depth. REMOTS® image from station 2-400NE illustrating an apparent "relict" dredged material layer. Map of sediment grain size major mode at the New London Disposal Site, July 1987. A layer ‘of fine sand overlies silit-clay in this REMOTS® image from station 4-200NE. Frequency distributions of small-scale surface boundary roughness values for all replicates at the New London Disposal Site and reference stations, July 1987. The distribution of apparent RPD depths, averaged by station, at the New London Disposal Site, July USNS 7/ « Frequency distributions of apparent RPD depths for all replicates at the New London Disposal Site and reference stations, July 1987. The distribution of infaunal successional stages at the New London Disposal Site, July 1987. Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Sr. 313s 3-14. Sys 3-167 See Sj UY) g 3-20. 320. S22 LIST OF FIGURES (CONT. ) A dense assemblage of tube-dwelling amphipods is visible at the sediment surface in this REMOTS® image from station 2-200NW. The distribution of Organism-Sediment Indices, averaged by station, at the New London Disposal Site, July 1987. Frequency distributions of Organism-Sediment Index values for all replicates at the New London Disposal Site and reference stations, July 1987. Near-bottom dissolved oxygen levels measured at selected stations at the New London Disposal Site in July 1987. A CTD/DO plot obtained at Station 2-400SE on 27 July 1987. A CTD/DO plot obtained at Station 400W on 27 July ILENE T/ A CTD/DO plot obtained at Station 4-400NE on 29 July 1987. A CTD/DO plot obtained at Station W-Ref on 29 July IUS)S37/ ¢ A CTD/DO plot obtained at Station NE-Ref on 29 Tully SS 7e Trace metal aincl weiweidl Ong anesc. Cc ashen concentrations in sediment collected at New London, July 1987. Trace metals and PCB's (as Aroclor 1254) in body tissues (dry weight) of Leptocheirus collected at New London, July 1987. MONITORING CRUISE AT THE NEW LONDON DISPOSAL SITE JULY 1987 120 INTRODUCTION The New London Disposal Site covers a one square nautical mile area located approximately two nautical miles south of the mouth of the Thames River, CT. This site, centered at latitude 41°16.1'N and longitude 72°04.6'W, has been monitored since ale \7/7/ 3 Ithas received an average of approximately 150,000 m- (200,000 yds~) of dredged material annually. During the period 24 July to 1 August 1987, field operations were conducted at the New London Disposal Site to provide information related to the environmental effects of dredged material disposal. The field operations included precision bathymetric and sediment-profile photographic (REMOTS ) surveys, sediment sampling for chemical and physical analysis, collection of a dominant suspension-feeding organism for bioaccumulation analysis of selected contaminants, and measurement of temperature, salinity, and dissolved oxygen in the water column at the disposal and reference sites. The primary objectives of this study were to: | Delineate the extent and topography of the dredged material deposited at the site; | Obtain sediment and tissue samples of a dominant suspension-feeding organism along the axis of predominant water movement to provide an initial assessment of the relationship between sediment contamination and biological uptake; and a Characterize the depth gradient in dissolved oxygen and assess near-bottom dissolved oxygen concentrations relative to REMOTS benthic analyses at the disposal and reference sites. 2.0 METHODS Py sil Bathymetry and Navigation The precise navigation required for all field operations was provided by the SAIC Integrated Navigation and Data Acquisition System (INDAS). This system uses a Hewlett- Packard 9920 series computer to collect position, depth, and time data for subsequent analysis, as well as providing real-time navigation. Positions were determined to an accuracy of +3 meters from ranges provided by a Del Norte Trisponder System interfaced to the INDAS. For the present survey, shore stations were established at known benchmarks at Millstone Point and New London Light, CT. The bathymetric survey was conducted at the New London Disposal Site on 28 July 1987. Individual depth measurements were determined to a resolution of 3.0 cm (0.1 feet) using a Raytheon DE-719 Precision Survey Fathometer with a 208 kHz transducer. A Raytheon SSD-100 Digitizer was used to transmit the depth values to the SAIC computer system. A more detailed description of these systems is provided in DAMOS Contribution #48 (SAIC, 1985). For subsequent analysis procedures, the actual speed of sound in water was determined from temperature and salinity data obtained using an Applied Microsystems STD probe. Bathymetric survey lanes were run east and west at a 25 meter lane spacing over a 1600 x 1600 meter area. The survey area encompassed the five disposal mounds and included an area within the disposal site 530 m northwest of the buoy, where 40% of the past year's dredged material presumably was deposited due to miscommunication about the disposal point (Figure 2-1). This lane spacing provided adequate resolution for subsequent data analysis and the production of detailed depth contour charts. During data analysis, raw bathymetric data was corrected to Mean Low Water by adjusting for both ship draft and changes in tidal height during the survey. A detailed discussion of the bathymetric analysis technique is given in DAMOS Contribution #60 (SAIC, 1989). 2.2 REMOTS Sediment Profile Photography REMOTS sediment-profile photographic surveys of the New London Disposal Site have been carried out since June 1984. REMOTS photography is used to detect and map the distribution of thin (1-20cm) dredged material layers. This capability compliments the precision bathymetric data which can resolve bottom elevation changes greater than 15 cm. In addition, REMOTS is used to map benthic disturbance gradients and to monitor the process of infaunal recolonization on and adjacent to disposal mounds. A detailed description of REMOTS image acquisition, analysis, and interpretative rationale is given in DAMOS Contribution #60 (SAIC, 1989). Forty-one REMOTS stations were occupied on 27 and 29 July 1987 in and around the New London Disposal Site (Figure 2-2). Three replicate images were obtained at each station located in a 6 x 5 grid with 200 m spacing centered at the disposal buoy. Additional stations were located at 800S (i.e., 800 meters south of station CTR), 1000S, 600E, 1000E, 1500NW, 400NW, 400SE, and 800SE. In order to compare ambient and on-site conditions, six replicate images were also obtained and analyzed at each of three outlying reference stations (W-Ref, NE-Ref and NLON-Ref). The location of the disposal buoy at the New London Disposal Site has not changed since the July 1986 REMOTS survey. That survey focused primarily on the NL-85 mound formed at the buoy. In order to delineate the extent of the dredged material deposited during the past year's disposal activities and to document any changes in bottom conditions, the results of the present survey have been compared with the results of the July 1986 survey. 253 Dissolved Oxygen The depth gradient in dissolved oxygen was characterized at REMOTS stations using a Rexnord Instruments Model 66 dissolved oxygen probe interfaced to an STD probe (Applied Microsystems, Ltd. Model STD-12). The STD-12, used to measure salinity, temperature, and pressure (depth), was mounted vertically on the REMOTS camera frame such that its sensors were located approximately 42 cm from the camera base. The attached Rexnord probe was mounted horizontally on the camera base frame such that its membrane was located between 6 to 9 cm above the sediment surface during deployment, depending on how deep the camera frame settled into the bottom. In this configuration, vertical hydrographic profiles were obtained during REMOTS image acquisition. The STD-12 is capable of sampling up to 8 scans per second and can store up to 7648 scans in 56k of internal RAM. Commands are sent to and data read from the instrument with a Compaq Portable II microcomputer via an RS-232 interface. Prior to commencing the REMOTS survey, the STD-12 was set to internally log data at 1 second intervals. The data were downloaded to the microcomputer during REMOTS film changes and stored on floppy disks for later analysis. The Rexnord Model 66 probe is a polarographic oxygen electrode (platinum-lead galvanic couple with a potassium-iodide electrolyte). The probe was covered with a 1 mm thick diffusion membrane. Calibration of the Rexnord Model 66 was performed at the SAIC Oceanographic Service Center by the standard method of comparison with Winkler titration (Strickland and Parsons, 1972). Calibration must be done whenever the membrane and electrolyte are changed. The calibration of the conductivity, temperature, and pressure sensors on the STD-12 was performed by the manufacturer. Salinity was calculated from conductivity data based on procedures described by Perkin and Lewis (1980). 2.4 Sediment Sampling and Analysis Triplicate sediment samples were collected with a 0.1 m2 Smith-McIntyre grab sampler at six stations located across the disposal site northwest to southeast (the direction of the dominant current regime) (Figure 2-3). Six polycarbonate plastic core liners (6.5 cm ID) were pushed into the sediment grab sample and extracted; the top 2 cm of sediment from five of these cores were combined and placed into bags for subsequent chemical analysis by the NED laboratory. The top 2 cm of the remaining core from each of the triplicate grab samples were combined and placed into a bag for subsequent physical analysis by the NED laboratory. The samples were kept on ice until delivered to the NED laboratory where they were stored at 4C until analyzed. The parameters measured include grain size, trace metals (Fe, As, Cd, Hg, Pb, and Cu), total PHC's and PCB's, and % total organic carbon. Analytical methods are those of the U.S. Environmental Protection Agency (Plumb, 1981). 2n5 Body Burden Analysis The test organisms (tubicolous amphipods) for body burden analysis were collected using the Smith-McIntyre grab at each of the six stations where sediment samples were taken (Figure 2-3). As the sediment was discharged and rinsed from the grab into a collection tub, the amphipods vacated their tubes and accumulated at the surface of the water and could be scooped out with a plastic dip net. Adding more water to the sediment and breaking down any sediment clumps released additional amphipods. Initial examination of amphipods collected in this manner revealed that approximately 95% (wet weight) of the individuals were of the genus Leptocheirus. Therefore, Leptocheirus was chosen as the target organism for all New London body burden stations. The animals were allowed to depurate for 24 hours in aerated seawater before being frozen for transport to the laboratory. Amphipod tissue was analyzed for five metals (Fe, Cd, Hg, Pb, and Cu) following methods in US EPA (1983) and total PCBs (as Aroclor 1254) following methods in US EPA (1977). These analyses were conducted by Environmental Monitoring Laboratory, Inc. (Wallingford, CT). 3.0 RESULTS 3.1 Bathymetry The contour plot resulting from the analysis of the July 1987 bathymetric survey at New London (Figure 3-1) depicts the five disposal points: NL-RELIC", "NL-I", "NL-II", "NL-III" and "NL-85". Comparison of this plot with the July 1986 plot (Figure 3-2) reveals a marked depth change at "NL-85". At this mound, depth decreased from 17.5 meters in 1986 to 15.5 meters in 1987, a maximum reduction of 2.2 meters. The peak of this mound was found to be approximately 60 meters south-southeast of the disposal buoy. Contours representing the "NL-RELIC", "NL-I", "NL-II" and "NL-III" disposal points were identical to those determined in 1986. Minimum depths remain the same at 13.0, 15.5, 15.5 and 14.5 meters, respectively, indicating no loss or addition of material at these mounds. According to the year's scow logs, of a total of 67,500 m (88,240 yd~) of dredged material was deposited at the New London disposal site, an estimated 12,400 m™ (16,225 yds”) of material was deposited approximately 530 m northwest of the disposal buoy on the extreme southern flank of the NL-RELIC mound. No depth change, however, was apparent for this_area in the contour chart. The remaining 55,100 m (72,000 yds~) of sediment, representing 82% of the year's disposed sediment as estimated from the scow logs, were added to the NL-85 disposal mound. The logs verify that almost all of this disposal occurred in the immediate vicinity of the buoy. Volume calculations based on a comparison of the depth data from the 1986 and 1987 surveys indicate a total of 43,000 (12,400 m~) of material was added during the past year's disposal activities. Because the majority of disposal operations took place at NL-85, a volume was also calculated for the five survey lanes passing directly over this mound. This volume, 33,951 m- (4615 m”), represents 79% of the total volume of material disposed within the survey area. The remaining 21% apparently consisted of relatively thin layers located farther out on the flanks of the NL-85 mound and/or in the area of inadvertent disposal 530 m northwest of the buoy. 32 REMOTS Sediment-Profile Photography Distinct dredged material layers with a thickness exceeding the penetration of the REMOTS prism (> 16 cm) were evident in the REMOTS images from stations in the immediate vicinity of the disposal buoy (Figure 3-3). These stations were CTR, 200E, 200W, 2-200SW, 200S, 2-200SE and 400SE. In general, the dredged material was characterized by a distinct boundary (i.e., RPD depth) between oxygenated sediment at the surface and sediment with extremely low reflectance below (suggesting apparent ‘high sediment oxygen demand, Figure 3-4). Similar low-reflectance dredged material exceeding the prism penetration depth was mapped in this same area in the July 1986 REMOTS survey. This made it difficult to distinguish between material deposited in the past year versus that from previous years. Less sharply contrasting layers of apparent dredged material were evident at stations 200N, 2-200NE, 2-400NE, 4-200NE and 4-400NE (Figure 3-5). The deposits at these stations, which occur in the vicinity of the NL-III and NL-II mounds, were more readily distinguished as "relict" material disposed in previous years (i.e., prior to the 1986-87 disposal season) . There was no evidence of low-reflectance dredged material layers in the northwest corner of the survey grid, where it has been presumed that roughly 20% of the 1986-87 material was disposed. Some clayey and sandy deposits observed in this region may represent disposed material. However, given the wide range of sediment types characteristic of the New London Disposal Site, it is impossible to unequivocally classify these heterogeneous sediments as dredged material. It should be noted that no apparent dredged material was observed at the three reference stations. The dredged material deposit extending south, east and west 200 to 400 m from the disposal point (Figure 3-3) was markedly smaller in areal extent than that observed at this location in July 1986. The discernible extent of the 1986 mound can be expected to shrink over time as a result of bioturbational mixing on the flanks of the deposit. Such mixing can erase evidence of thin layers of deposited material by homogenizing near-surface strata. This phenomenon was documented on the flanks of the Field Verification Program (FVP) mound during the first year of monitoring (SAIC, 1982). In addition, significantly less material was disposed at the NL-85 buoy in the past year relative to prior years. It was therefore likely that the dredged material deposit by REMOTS (Figure 3-3) largely consisted of material deposited prior to the July 1986 survey, with a minor addition of material deposited in the past year. As determined from REMOTS images, surface sediments at most stations consisted of mixtures of silt-clay and very fine sand (>4-3 phi) (Figure 3-6). Slightly coarser-grained sediment, consisting of very fine and fine sands (4-3 and 3-2 phi), occurred in the southwest and in the northwest corner of the sampling grid. At several stations (2-200SW, 200W, 400W, and 4-200NE), layers of fine sand overlaid silt-clay (Figure 3-7). This possibly reflects inputs of coarse-grained dredged material. Sediments at the three reference stations consisted of silt-clay to very fine sands (>4-3 phi). The frequency distributions of boundary roughness values for the disposal area and reference stations (Figure 3-8) indicate that no significant difference exists between these stations (Mann Whitney U-test; p = 0.4603). Also, there has been no change in small-scale bottom roughness in the vicinity of the NL-85 mound since the July 1986 survey (Mann-Whitney U-test; p = 0.2929). The mapped distribution of apparent RPD depths at the disposal site (Figure 3-9) reveals that most stations exhibited an RPD depth greater than 3.0 cm. Five stations from the disposal point south (CTR, 200S, 400S, 400SE, and 1000S) show values 3.0 cm. All three reference stations exhibited average RPD depths 3.9 cm. Overall, RPD values were significantly shallower at the disposal area than at the reference sites (Mann-Whitney U-test; p = 0.0299) (Figure 3-10). The RPD values in the disposal site have significantly deepened since the July 1986 REMOTS survey (Mann-Whitney U-test; p < 0.001). This suggests enhanced biogenic sediment reworking by the infaunal benthos. The mapped distribution of infaunal successional seres at the disposal site (Figure 3-11) shows that only one station, 4-200SE, lacks evidence of Stage III infauna. This contrasts with the pattern observed in July 1986 when many stations lacked evidence of deep-dwelling, deposit-feeding taxa. The widespread appearance of Stage III taxa at the disposal site indicates that successful infaunal recolonization of the region is occurring. The disposal activity of the past year does not appear to have markedly affected the rate of this recolonization. In addition, tube-dwelling amphipods were evident at many of the stations in the disposal area (Figure 3-12). These Stage II seres have been observed in all previous New London REMOTS surveys. Stage III taxa were present at all three reference stations, while Stage II taxa were observed only at NLON-Ref. The distribution of Organism-Sediment Indices (OSI) at the disposal site (Figure 3-13) indicates that most stations exhibited relatively high OSI values; this reflects the high-order successional status and relatively deep RPD values present across the site. It is noteworthy that the lowest OSI value occurs well south of the disposal area (station 1000S). This relatively deep area may be subject to periodic hypoxic conditions which were not occurring at the site. OSI values within the disposal site do not differ significantly from the values at the reference stations (Mann-Whitney U-test; p = 0.0715) (Figure 3-14). OSI values were significantly greater than those observed in July 1986 (Mann-Whitney U-test; p < 0.001). This increase in OSI values reflects the successful infaunal recolonization which has occurred at the site in the past year. 3.3 Dissolved Oxygen Near-bottom dissolved oxygen (DO) concentrations were analyzed at approximately 50% of the REMOTS stations occupied at New London on 27 and 29 July (Figure 3-15). The sampling on 27 July occurred solely at stations in and immediately adjacent to the disposal site; the DO values on this day ranged between 6.57 mg/l to 7.35 mg/l. On 29 July, the reference stations and stations to the extreme south and north of the site were found to have near bottom DO concentrations ranging from 3.58 mg/l to 7.02 mg/l. It is noteworthy that the three reference stations (W-Ref, NE-Ref and NLON-Ref) and 1500NW had the lowest near-bottom DO values (3.58, 4.00, 4.37, 3,61, respectively). Plots of the depth gradients in dissolved oxygen, temperature, salinity, and density (as sigma-t) at the selected REMOTS stations indicated in Figure 3-15 are given in Appendix I. A representative CTD/DO plot obtained on 27 July at station 2-400SE (Figure 3-16) indicates that the water column was stratified, with evidence of a thermocline and halocline (and resultant pycnocline) at a depth of 12 to 15 m. Above and below this steep density gradient, the water column appears to have been well-mixed, as indicated by the vertical structure of the temperature, salinity, and DO data. In contrast, the 27 July CTD/DO plot from station 400W (Figure 3-17) does not show strong gradients in any of the measured parameters. The gradual decrease in temperature and increase in salinity and density with depth indicates an unstratified water column. On 29 July, there were wider variations in the vertical distributions of temperature, salinity, and density. For example, the steady decrease in temperature and gradual increase in salinity and density at station 4-400NE (Figure 3-18) indicate a lack of strong vertical gradients in these parameters. Conversely, a complicated and stratified water column structure was observed at station W-Ref (Figure 3-19), where there was a near-surface (i.e., less than 5 meters deep) thermocline, halocline, and pycnocline as well as sharp gradients in temperature, salinity, and density at a depth of 18-20 meters. Concurrently, station NE-Ref exhibited remarkable uniformity in temperature, salinity, and density throughout the water column (Figure 3-20). There was no notable depth gradient in dissolved oxygen concentrations at any of the stations sampled on 27 July. All of the plots from this day show only a slight, steady decrease in DO concentrations with depth. With the exception of stations 800S and 1000S, near-bottom DO concentrations measured on 29 July were generally lower than those measured on the 27th. However, as on 27 July, DO concentrations did not exhibit marked gradients with depth. So Sediment Characteristics Sediments at all six stations appeared olive gray with variable amounts of fine sand and silt/clay as the dominant grain-size fractions (Table 3-1). Stations CTR and 400SE contained relatively higher percentages of silt and clay (69% fines), while fine-grained sand occurred in higher proportions than silt at stations NLON-Ref, 800SE, 400NW and 1500NW. The mean concentrations of Hg, Pb, As, Cd, and Cu in surface sediments at the six stations sampled (Table 3-2) were all at Low levels, according to the New England River Basins Commission's (NERBC) interim criteria (NERBC, 1980). While such criteria do not exist for Fe and percent total organic carbon (Table 3-2), the results of statistical testing show that at all stations, except 400NW and 400SE, metal concentrations and percent total carbon were below detection limits or were not significantly different from those at the reference station (Table 3-3). Concentrations of Pb, As, Fe, Cu, and percent total organic carbon at station 400SE were all significantly elevated relative to NLON-Ref levels, whereas concentrations of As and Cu at 400NW were depressed (Table 3-3). Concentrations of metals and percent carbon were elevated above reference levels at station 400SE within a factor of one or two (Figure 3-21). Concentrations of organochlorine pesticides and PCB's in sediments at New London were generally below the analytical detection limits at all stations (Table 3-4). Exceptions to this were heptachlor at station 400NW, which was just above the detection limit, and PCB's as Aroclor 1232 at stations CTR and 1500NW and PCB's as Aroclor 1242 at stations 800SE and 400NW. Concentrations of PCB's at these stations were well below the 1.0 ppm level considered to be confirmation of high contamination according to the NERBC interim criteria (NERBC, 1980). 3e5 Body Burden Analysis The results of the triplicate analyses for five trace metals (Cd, Pb, Cu, Fe, and Hg) in body tissues of the suspension-feeding amphipod Leptocheirus are reported on a dry weight basis (Table 3-5). In the case of station center (CTR), the laboratory was sent two jars of organisms (collected on two different sampling days) which were to be combined and treated as a single sample. Inadvertently, the two jars were treated as separate samples and the results were reported accordingly (i.e., CTR#1 and CTR#2). Concentrations of both cadmium and mercury in Leptocheirus were below analytical detection limits at all stations. Pb, Fe, and Cu were elevated at station 400SE and Cu was elevated at station CTR#2 (Figure 3-22), although in all cases the magnitude of these elevations above the reference were less than a factor of three. Statistical tests confirm that Pb and Cu at CTR#2 and 400SE, Fe at 400SE, and Cu and Fe at 1500NW were all significantly higher than the reference concentrations (Table 3-6). Elsewhere, Leptocheirus body burden levels were either significantly less than or did not differ significantly from the reference animals. The results of the triplicate analyses for PCBs (as Aroclor 1254) in body tissues of Leptocheirus (Table 3-7) indicated that concentrations were below the detection limit in two of the replicates at station 1500NW and one replicate at station 400NW. Although the highest PCB body burdens occurred at the reference station (Figure 3-22), the difference between the PCB concentrations in the reference animals and those from the on-site stations was not statistically significant, except at station 1500NW where PCB body burdens were significantly lower than the reference (Table 3-6). 4.0 DISCUSSION 4.1 Bathymetry The results of the bathymetric survey at the New London Disposal Site revealed a significant addition of dredged material at the "NL-85" mound, centered approximately 60 meters south-southeast of the disposal buoy. Scow logs verified that approximately 82% of the material was disposed at this location in the past year. No depth change was observed 530 m northwest of the buoy on the southern flanks of the NL-RELIC mound, where an estimated 12,400 cubic meters of material was disposed due to miscommunications about the disposal location. The lack of an observable depth change at the northwest location suggests that the material deposited there occurred in layers less than 15 cm thick, which could not be detected reliably by acoustic measurement. In addition, although some potentially allochthonous sediment was observed in the REMOTS images from this area, it is impossible to unequivocally classify this sediment as dredged material due to the heterogeneity of the sediments historically disposed within the New London site. Any disposed material which might be present probably occurs in discontinuous, thin coarse-grained layers, making it difficult to detect by either bathymetry or REMOTS. A comparison oF the dredged material volume estimated from scow logs_ (67,500 m”) with the volume calculated from depth data (43,000 m>) indicates a decrease in volume of 36%. If only the area in the vicinity of the NL-85 mound is considered, a scow estimate of 55,100 m- compares with a volume estimate of 33,951 m-, representing a 38% decrease in volume. These decreases in estimated volume compare well with the results of a study by the New York District COE (Tavolaro, 1984), where it was determined that the volume of material detected on the bottom by acoustic techniques was approximately 40.7% less than the scow volume estimates. Of this 40.7% volume decrease, 15.4% is attributed to the loss of interstitial water during disposal and compaction of the material after impacting the bottom. The remaining 25.3% presumably occurs as thin layers of dredged material not detected by the survey fathometer. 10 4.2 REMOTS Sediment Profile Photography The present REMOTS survey indicates that the areal extent of dredged material was well within the disposal site boundaries and, in large part, the material occurred within 400 meters of the disposal buoy. In many of the REMOTS images, it was difficult to determine precisely how much of this dredged material was deposited during the past year versus previous years. Comparing the bathymetric contours from 1986 and 1987 (Figures 3-1 and 3-2) shows the disposal mound formed in the past year was approximately 300 m in diameter and centered southeast of the disposal buoy. The REMOTS data (Figure 3-3) indicates that dredged material layers in excess of the prism penetration (i.e., greater than about 15 cm in thickness) extended approximately 200 m farther west, south, and southeast than indicated by the bathymetric data. If these layers had actually been deposited since the 1986 survey, then they should have been detected acoustically. The fact that no changes in bathymetry correspond with these dredged material layers suggests that much of this material was probably not deposited in the past year but rather represents material which was seen in these locations (with both REMOTS and bathymetry) at the time of the July 1986 survey. Some clayey and sandy sediments, probably allocthonous, were present approximately 400 meters northwest of the disposal point. This may represent the dredged material which was mistakenly disposed in this area. However, due to the sediment heterogeneity present at this site, definitive identification of these materials as new dredged material was not possible. Infaunal recolonization at the site is proceeding well within expected rates based on previous DAMOS surveys; head-down deposit-feeding assemblages (Stage III) were found across the survey area. This indicates that significant infaunal recolonization has occurred since the 1986 survey. Also, tubicolous amphipods (Stage II taxa) continue to be a major faunal component of the region. At the three reference stations located west, northeast, and east of the disposal site, Stage III taxa were also abundant, while Stage II forms were observed only at the eastern reference station (NLON-Ref). An3 Dissolved Oxygen Regime In view of the objectives of the CTD/DO sampling at New London, the results illustrate the difficulties in characterizing oceanographic dissolved oxygen regimes based on instantaneous measurements at this site. A major confounding factor stems from the fact that the New London site is located within an estuary, very close to the opening to the Atlantic Ocean (The Race), where dissolved oxygen concentrations typically vary diurnally, tidally, 11 and seasonally. The results indicate small-scale spatial and temporal variability not only in DO concentrations, but also in the vertical distribution of salinity and temperature. In part, this variability is the result of frequent tide or wind-induced mixing of the water column. In addition, estuarine flow patterns (i.e., the interaction of variable freshwater inputs from the Connecticut and Thames Rivers with changing tidal regimes) move parcels of water having very different temperature, salinity, and DO characteristics through the area at different times. While some of the CTD/DO plots obtained on 27 and 29 July suggest that the water column was seasonally stratified, others show a vertically mixed pattern at a variety of bottom depths with no apparent correlation between depth or location. Given the above considerations, the observed changes in temperature, salinity, and density at depth more likely reflect the passage of different parcels of water at the time of sampling rather than a stable and persistent density gradient. The absence of near-bottom oxygen depletion, and the uniform vertical distribution of dissolved oxygen observed at nearly every station, further suggest that the water column was well-mixed at the time of the survey. Similar results were found at the Western Long Island Sound (WLIS) Disposal Site and the Central Long Island Sound (CLIS) Disposal Site in 1987. The WLIS survey was performed in November 1987 and a well-mixed water column was seen (due to the cooler water temperatures). At CLIS, which was sampled in late August and early September 1987, results were similar to those found at NLON. An absence of near-bottom oxygen depletion and a uniform vertical distribution of dissolved oxygen concentrations suggested a mixed water column at the time of the CLIS survey. In the absence of a strong and persistent pycnocline, the development of hypoxia or anoxia in near-bottom waters at New London would not be expected. The data support this conclusion but also indicate a strong daily fluctuation in the DO regime. On 27 July, DO concentrations throughout the water column were well above levels which have been defined as biologically "critical" (Table 4-1). Two days later, most of the DO values at the site could still be considered aerobic but were noticeably lower, while values at three nearby reference stations (W-Ref, 1500NW and NE-Ref) were in the "hypoxic" range (Table 4-1). These results might be attributable to either the in-situ consumption of oxygen or an influx of low DO parcels of water. The sampling used in the present survey did not allow accurate assessments of either the spatial distribution of such water masses or the frequency and duration of their passage. One of the objectives of the CTD/DO sampling at New London was to assess near-bottom dissolved oxygen concentrations relative to REMOTS benthic analyses at and near the disposal site. While it is difficult to relate the instantaneous DO measurements to potential biological effects, the CTD/DO results generally show that while the potential for transient hypoxic 12 conditions exists, most near-bottom waters at the site were aerobic (> 4 mg/l) and had higher DO concentrations than the reference stations at the time of the survey. It had been hypothesized that stressed benthic habitats at the site in 1986 were directly related to the Sound-wide phenomenon of near-bottom hypoxia. There was no evidence in the REMOTS images from 1987 of widespread hypoxic stress in the benthos at New London. Significantly higher OSI values in 1987 compared to 1986 suggest that successful infaunal recruitment and recolonization has occurred at the site in the past year. Such recruitment success indicates an absence of chronic near-bottom hypoxia in the weeks and months preceding the survey. 4.4 Sediment Characteristics The results of physical testing of sediments at New London, which show that mixtures of silt-clay and very fine sand predominate at the surface, generally were in good agreement with the results obtained in the REMOTS survey. These results reflect both the natural heterogeneity in sediment types characteristic of the site, as well as the addition of dredged material which consisted primarily of sand and silty-sand with lesser amounts of clay. One objective of the sediment chemical analyses was to determine the concentrations of sediment-associated contaminants that were deposited at the site and to determine whether the contaminants were subject to further resuspension and transport. As indicated by the REMOTS dredged material mapping (Figure 3-3), station 400SE, the only station with significantly elevated levels of several metals and % total carbon compared to NLON-Ref, is located within the mound formed by recently disposed material. While 400SE is elevated compared to NLON-Ref, the metals (for which NERBC interim criteria exist) occur at this and other stations exclusively at Class I levels. This is consistent with their classification in the dredged material prior to disposal. Likewise, significant contamination was not observed in and around the disposal mound in terms of Fe, % total carbon, organochlorine pesticides and PCB's. The lack of a significant contaminant signature in the disposed material confounds attempts to assess contaminant resuspension and transport. Although the sediment chemistry data (Figure 3-21) indicate that the stations on the mound (CTR and 400SE) were higher in concentrations of trace metals and PCB's, a consistent concentration gradient was not evident. The statistical results (Table 3-3) show that contaminant levels at these outer transect stations were not significantly different from the reference station. If transport was occurring along the transect 13 (the axis of predominant current movement), it is expected that the off-mound transect stations would show higher contaminant levels than the reference station. As a second approach to addressing the question of contaminant transport, a statistical test (Kruskal-Wallis test) was performed to determine differences in contaminant concentrations among the five transect stations (1500NW, 400NW, CTR, 400SE and 800SE). This test showed that for those contaminants which were detected (As, Cu, Fe, and Pb), there was no significant difference in concentrations among the five stations. As the next step, for each of these metals the replicate values obtained at the five transect stations were pooled and tested against the three replicate reference values (two in the case of Hg). This test (Mann-Whitney U-test) showed that there was no significant difference in the metal concentrations between the reference station and the pooled transect stations. The fact that the transect stations do not differ from each other and collectively do not differ from the reference station strongly suggests that resuspension, transport, and redeposition of the contaminants is not occurring. 4.5 Body Burden Analysis Reflecting the pattern of sediment contaminant levels, Leptocheirus body burdens at stations in and around the disposal site were generally below detection limits or were significantly less than or not different from those at NLON-Ref. The exceptions to this are various elevations of Pb, Cu, and Fe at stations CTR#2, 400SE and 1500NW (Table 3-6). The variations between CTR#1 and CTR#2 in Pb, Cu, and Fe levels are notable. However, based on the excellent recovery for these elements from spiked laboratory quality assurance procedural blanks (Pb = 88%, Fe = 99%, Cu = 99%), the results reflect station population variability as opposed to analytical inconsistencies. The objective of the body burden analyses was to assess the relationship between sediment contamination and biological uptake. This relationship was examined for Pb, Cu, and Fe, the only three contaminants displaying both body burdens and sediment concentrations significantly above detection limits. The results of a nonparametric test for association (Spearman's coefficient of rank correlation) show that the mean body burden concentrations of Fe and Cu are not significantly associated with the mean sediment concentrations of these metals (Spearman's rho = 0.66, P > 0.05 for both metals). There was some suggestion of a significant association between mean body burdens and sediment concentrations of Pb (Spearman's rho = 0.81, P = 0.051), but the small sample size in conjunction with the uncertain exposure history of the test organisms implicit in studies of this nature render any definitive conclusions tenuous. 14 5.0 CONCLUSIONS The results of both the bathymetric and REMOTS surveys at New London indicate an accumulation of dredged material well within the disposal site boundaries in the immediate vicinity of the buoy. The bathymetric results show that the mound formed as a result of the past year's disposal activities was approximately 300 m in diameter centered about 60 m southeast of the buoy. The REMOTS images show dredged material layers exceeding the prism penetration depth both on the mound and extending approximately 200 m farther west, south, and southeast than indicated by the bathymetric data. While some of this material was deposited in the past year, it is likely that much of it was the result of disposal prior to the July 1986 REMOTS survey. There was no depth change observed 530 m northwest of the buoy on the southern flanks of the NL-RELIC mound, where some dredged material was disposed due to miscommunications about the precise disposal point. The apparently allocthonous sediments seen in some REMOTS images from this location can not be identified unequivocally as dredged material due to the heterogeneity in sediments at the site. It is hypothesized that the amount of material indicated in scow logs to have been disposed northwest of the buoy occurred in discontinuous, thin layers which were difficult to detect by either bathymetry or REMOTS. The widespread occurrence of Stage III taxa at New London indicates that despite on-going disposal activities, significant infaunal recolonization has occurred since the 1986 REMOTS survey. As in 1986, tubicolous amphipods continued to be a major faunal component of the region. The high order successional status and relatively deep RPD values present across the site result in OSI values which were significantly greater than those observed in July 1986. The relatively high OSI values in 1987 further suggest a lack of stress which might otherwise be attributed to near-bottom hypoxia in this region of the Sound. The absence of hypoxia was confirmed by the results of the CTD/DO sampling, which show that while the potential for transient hypoxic conditions exists, most near-bottom waters at the site were aerobic (i.e., > 4 mg/l DO) and had higher DO concentrations than the reference stations at the time of the survey. It is hypothesized that the observed small-scale spatial and temporal variability in both DO concentrations and the vertical distribution of salinity, temperature, and density was due to the complex interplay of tidal, riverine, and wind-induced water column mixing, which is characteristic of an estuary such as Long Island Sound. 15 The results of physical testing of sediments at New London were in good agreement with the REMOTS grain-size analyses and reflect both the natural heterogeneity in sediment types characteristic of the site, as well as the addition of dredged material consisting of sand and silty-sand with lesser amounts of clay. Chemical analyses of the sediments indicate the occurrence of several metals (Hg, Pb, As, Cd and Cu) and PCB's at Low concentrations; this is consistent with the classification of these contaminants in the dredged material prior to disposal. There was no significant contamination observed in and around the disposal mound in terms of Fe, % total carbon, and organochlorine pesticides. Based on statistical tests, it does not appear that contaminant resuspension and transport is occurring, although the lack of strong contaminant signature in the recently deposited material makes it difficult to assess such processes unequivocally. Contaminant levels in tissues of the suspension-feeding amphipod, Leptocheirus, at stations in and around the disposal site were either below detection limits, significantly less than, or not different from levels obtained at the reference station. Statistical tests for association between sediment concentrations and body burdens indicate a lack of strong correlation between the two, but definitive conclusions cannot be made because of the relatively small sample sizes. 16 REFERENCES New England River Basins Commission (NERBC). 1980. Interim Plan for the Disposal of Dredged Material from Long Island Sound. NERBC, Boston, Ma. 55 p. Perkin, R.G. and E.L. Lewis. 1980. The practical salinity scale 1978: Fitting the data. IEEE J. Oceanic Eng. OE-5: 9-16. Plumb, R.H. 1981. Procedures for Handling and Chemical Analyses of Sediment and Water Samples. Tech. Report EPA/CE-81-1. Rhoads, D.C. and J. Morse. 1971. Ecological and evolutionary significance of oxygen-deficient marine basins. Lethaia 4: 413-428. SAIC. 1982. Site Selection and Baseline Surveys of the Aquatic Disposal Site, Field Verification Program (FVP). U.S. Army Corps of Engineers, New England Division, Waltham, MA. DAMOS Contribution #23. SAIC. 1985. Standard Operating Procedure Manual for DAMOS Monitoring Activities. U.S. Army Corps of Engineers, New England Division, Waltham, MA. DAMOS Contribution #48 (SAIC Report # SAIC-85/7516&C48) . SAIC. 1989. Monitoring Surveys at the New London Disposal Site, August 1985 - July 1986. U.S. Army Corps of Engineers, New England Division, Waltham, MA. DAMOS Contribution #60 (SAIC Report # SAIC-86/7540&C60) . Strickland, J.D.H. and T.R. Parsons. 1972. A Practical Handbook of Seawater Analysis. Fish. Res. Board Can. Bull. 167pp. Tavolaro, J.F. 1984. Sediment budget study for clamshell dredging and ocean disposal activities in the New York Bight. Environ. Geol. Water Sci. 6 (3): 133-140. U.S. Environmental Protection Agency. 1977. Analysis of Pesticide Residue in Human and Environmental Samples. HERL, Research Triangle Park, NC. U.S. Environmental Protection Agency. 1983. Methods for the Chemical Analysis of Water and Wastes. EPA Pub. No. 600/4- 79-020. 17 Py Sort Se eats yeh Eo eawone eal poe a po cee nes pabed ts vith thin ae “Seeakce. aie peo ot a sex! ins e Se, and al 4 te ante Pate ks ereguivedcnl iy oissupa pd ace we fot sifferant en annie note «(Besa lev 26~ eh . Vogwa ~. {e222 isaogeid nohnold welt etl) te syevavd paige feet .97h2 Wek ,aisanioos To adyod yarA .2.U .2er yfeu = fespea - OIAe) 00% ncitadixine? AOMAd 4AM \gadtieW ,aedeiva ons - (OS9SOR2 0) SB OEAS. | | Soodbask tnotsoes¢ & .s8eL .,ecoets? .4-9 bre — ei $GGS0E ,Livh .1sD breoe .uet .delt .eleyteae ifettamslo 10) youse.tapbyd Ineai her 98er = te .ouaiover a ixpY wat aft wl aoidivistas Ieecoanth nsodo Bae onighesh : -Qbf%-Cttg =(€) 2 .t92 wisW .ined .nosivas “.tipra Pe ico elaylenA .STeL syonepA coizostozd Setnemmosivit .2,5 ASH .aslqes® (etnemioxived Sas soem at ocblaen ebioisest Ou , axed efonsla? doxsdnst si? sot ebodsel »ESUE veorabd moitoeso1wg [eygennetivadl .2.0 ~b\G02@ .o8 .dod AW .asie6eW bos 12276" 3a ziay lend a ee TI «& Table 3-1 Results of Physical Testing of Sediment Collected at New London, July 1987 Visual % Coarse % Medium % Fine Station Classification Material Sand Sand % Fines NLON-Ref olive gray- <1 2 59 39 silty sand CTR olive gray- <1 7 24 69 organic sandy silt 800SE olive gray- <1 6 49 45 silty sand 1500NW olive gray- 4 6 44 46 silty sand 400NW olive gray- 2 aba 59 28 silty sand 400SE olive gray- ob Ps as e°) gt sa vs one a ATWTT UoTZOSejSep wNUTUTW MOTEeg = PN 97°0 G - LSS lE v°T 6 Z0°O "ASd *paSsFt 8T°T GT - 00€ ‘ST G°9 v2 80°0 ueoH G8°0 €T PN OO€‘ET 1° 9T 90°0 ¢/aSso008 66°0 Gl PN 00z‘ET G°9 Le L0°0 z/4S008 O2t TZ PN 00r‘6I 6°L ve OT°O Tt/dS008 [Leo ZU - G6G‘E 6°T OV - "Aed *pyASsF €6°T ST - L96‘2T at OE - uroW OWE 6z PN 000‘ZLT 6°9 6L PN €/aLo Oe ai 6 PN OOT‘OT (SO OT PN 7/aLO Oe 10 8 PN 008‘TT 6°E€ OT PN T/aLO ZZ°0 T - 99Z‘T 7°O v 0 "ASd °PpASF S6°0 VI - LOTT 0°9 0z L0°0 ues OZ? E Gil PN o0€ ‘ST v°9 Gc PN €/JOU-NOIN L8°0 Gi PN OOV‘rT 0°9 6T L0°0 Z/J2U-NOIN DLO VT PN 008‘ZT 9°¢ ALi L0°0 T/JOuU-NOIN uoqaie) OTuUebAO udd wdd udd udd wdd wdd TeIOL % Late) po 34 sv dd 6y (qu6tem Arq uo peseg suoTjerAUeDUOD) L86t ATn¢e ‘UOpucT MeN Ae PeAOSTTOD JUseWTpes soezans ut suoTjerjUusoUOD UogqreD OTUeHAO T[ejO] pue [TejOW ooPAL c-€ 29TAeL SJTIWTT UuoTOeVZeEp wnuUTUTW MOTeg = PN GiaO G - REBATE OuaG 6 Z0°O "Aad *PASF EGET GZ - SESeLL z°8 9€ 9T°0 ueohn Ollie TE PN 007‘8T SOR} oF GT°O €/AS00P 06°T €z PN 008’ST 1/4 O€ 9T°0 Z/ASO0P 06°T Ze PN OO€’6T 36 Ze 81°0 T/ASO00P Gi 0) Zz = 96L‘Z LO) OT - “Aed “PAST 76°0 ee - L06‘0T O°? lec - ure 78°0 Gil PN 008’E€T v°v ia PN €/MNOOP 8S°0 6 PN 0278 GS ic PN Z/MNOOP Ort Gil PN OOL‘OT vv Le PN T/MNOOP GL°O GT - 601T’8 Gai VI Cia PASC) PAS aaa ile - L90‘9T wen 82 vI°O uroW Ocal oT PN 008‘2T 1G 61 90°0 €/MNOOST 06°T [Ie PN 00€‘’SZ 0°OT VP (BOO) Z/MNOOST 0v°O 6 PN OOO 0°9 02 PN T/MNOOST uwoqazed OTuebio wdd wdd wdd wdd wdd wdd SzeOT [dey /uoTAIeAS Tei0L & nd po og sv dd 6H (penutjuos) z@-€ eTqeL Results Station CTR 800SE 1500NW. 400NW 400SE ns = Table 3-3 of Statistical Testing for Significant Differences in Chemical Concentrations in Sediment Collected at New London, July 1987 Variable % Total Hg Pb As Be ca Cu Carbon na ns ns ns na ns ns ns ns ns ns na ns ns ns ns ns ns na ns ns na ns = ns na = ns ns + + ap na + + concentrations significantly higher than Reference station (p < 0.05, Mann-Whitney U-test) concentrations significantly less than Reference station (p < 0.05, Mann-Whitney U-test) not significantly different from Reference station (p > 0.05, Mann-Whitney U-test) statistical test not applicable because chemical concentrations were below detection limits in some or all replicates "O09¢T AOTOOAY AOF FEU OF ALSTTWIS ore BOZT Pue Z9ZT SAOTOOAY AOF SATWTT UOTASSRISP SULexx an an an an an aN aN aN aN an aN an an an aN aN aN an aN aN an an an an an aN an an aN ASOOV an an aN an aN O8e an an aN aN an an GN an c8 aN an an an aN aN an an aN 6°8 aN an an aN MNOOYV *(qdd) qy6tem Arq uo peseg ere suotTjeAQUeDUOD GN aN aN aN GN an 08d aN aN an aN aN aN aN an aN aN aN aN aN aN aN aN an an an aN an aN MNOOST aN aN an aN aN O9T aNn aN an aN aN aN aN an aN aN aN an aN an an aN aN aN an aN aN aN aN 4S008 an aN aN aN an aN ACA aN aN aN aN aN aN aN aN an aN’ aN aN an aN aN an an an aN aN aN aN abo an aN aN aN an an aN aN an aN an an aN an an aN aN aN aN an aN an an an an an an aN aN aga SQTUTT uoT359030d peqoejep jou = aN 89¢T-290 TO0AW c9¢T-A0TO0OAYW 097¢T—-190 TO0AY VS¢T-4t0 T901V 87?CT-190 TOOAY cvVceLT—-AOTOOAW cECT-AO TOOAW TéceéT—-10 To01zy 9TOT—-190 TO0AY epAyepte utazpug euseydexoy, sueprOTYUO euojey uUTApu_ ToT YyoAKoyASH Ldd-,7‘% eyey[ns uey Tnsopuy qad-.v’7 II ues [TNsopuy uTapug aqd-.0'P? uTIpTetd I ues [Tnsopuy eptxods AoTYyoOe dey UTIPTW AoTYyoeRejdey (euepuTT) OHa-euUIeD OHE-e3T9d OHd-& 30° OHd-eUudTY aojouNeIed °286T A[Tnec ‘uopuoyT MeN Ae PSOST TOD A4usUwtpes ut s,qdd pue septoTysed suTAOTYOoueb1z0 y-€ 9TqeL Table 3-5 Trace Metal Concentrations in Body Tissues (Dry Weight) of Leptocheirus Collected at New London, July 1987 Concentrations in ppm Station/Replicate cd Pb Cu Fe Hg NLON-Ref/1 <0.26 3.6 81.9 663 <0.03 NLON-Ref/2 <0.26 4.7 90.2 725 <0.03 NLON-Ref/3 <0.26 cial 87.6 674 <0.03 Mean <0.26 3.8 86.6 687 <0.03 +Std. Dev. - 0.8 4.2 33 = CTR #1/1 <0.65 3.9 50.7 458 <0.03 CTR #1/2 <0.65 <3 50.7 417 <0.03 CTR #1/3 <0.65 <3 54.6 505 <0.03 Mean <0.65 B53} 52.0 460 <0.03 +Std. Dev. - 0.5 Ao 3 44 - CTR #2/1 <0.64 Bq iL 284.1 404 <0.03 CTR #2/2 <0.64 5.1 247.1 39/7) <0.03 CTR #2/3 <0.64 5.1 207.6 359 <0.03 Mean <0.64 5.1 246.3 380 <0.03 +Std. Dev. > 0 38.3 2S} = 800SE/1 <0.28 <3 79.7 671 <0.03 800SE/2 <0.28 3.4 84.8 660 <0.03 800SE/3 <0.28 <3 78.5 751 <0.03 Mean <0.28 Bieak 81.0 694 <0.03 +Std. Dev. - 0.2 3633 50 = 400NW/1 <0.27 352 47.9 872 <0.03 400NW/2 <0.27 <3 69.7 692 <0.03 400NW/3 <0.27 <3 62.8 840 <0.03 Mean <0.27 3 +Std. Dev. = O. 11.1 96 = Table 3-5 (continued) Concentrations in ppm Station/Replicate ca Pb Cu Fe Hg 400SE/1 <(0) 5 SAL f3}.5 al 130.3 1405 K(0) 6 ()3} 400SE/2 <0.51 Oren: WAS 1282 <0.03 400SE/3 K(ig Bil 10.1 126.2 1242 <0.03 Mean <0.51 8.1 NMBA 67 1310 <0.03 > sca. Dev. = 2 do’ 85 = 1500NW/1 <0.42 Sree 114.4 898 <0.03 1500NW/2 <0.42 4.2 106.8 898 <0.03 1500NW/3 <0.42 4.2 106.8 881 <0.03 Mean <0.42 4.5 109.3 892 <0.03 acisneel., IDENo = 0.5 4.4 10 = Table 3-6 Results of Statistical Testing for Significant Differences in Chemical Concentrations in Body Tissues of Leptocheirus Collected at New London, July 1987 Variable PCBs Station cd Pb Cu Fe Hg (as Aroclor 1254) CTR #1 na ns = = ns ns CTR #2 na + + - ns ns 800SE na ns ns ns ns ns 400NW na ns = ns ns ns 400SE na AP + + ns ns 1500NW na ns + + ns = + = concentrations significantly higher than Reference animals (p < 0.05, Mann-Whitney U-test) - = concentrations significantly less than Reference animals (p < 0.05, Mann-Whitney U-test) ns = no significant difference between station value and Reference value (p > 0.05, Mann-Whitney U-test) na = not applicable, statistical tests were not performed because of varying analytical detection limits Table 3-7 PCBs (as Aroclor 1254) in Body Tissues (Dry Weight) of Leptocheirus Collected at New London, July 1987 Concentrations in ppm Station/Replicate PCBs (as Aroclor 1254) Mean + Std. Dev. NLON-Ref/1 Ons 72 NLON-Ref/2 0.105 NLON-Ref/3 0.180 (Oh ee Rc) CEReH 1a 0.248 CTR #1/2 0.080 CER 41/7/73 @. LBA 0.153 + .086 CTR #2/1 0.033 CTR #2/2 0.178 CTR #2/3 Ops2 0.134 + .088 800SE/1 Os 227 800SE/2 0.163 800SE/3 0.150 Opts Oneal: 40ONW/1 0.094 400NW/2 0.057 400NW/3 <0.0051 Qn0520 2045 400SE/1. 0.115 400SE/2 0.101 400SE/3 0.138 Oeits =) O19 1500NW/1 0.016 1500NW/2 <0.0051 1500NW/3 <0.0051 0.009 + .006 1 pelow detection limit Table 4-1 Ecologically Important Dissolved Oxygen Ranges as Determined from Permanently Stratified Low- Oxygen Marine Basins (from Rhoads and Morse, 1971) Dissolved Oxygen Range (mg/1) Facies S 448 Aerobic 4.2 to 0.41 Hypoxic* 0.4 to 0.14 Dysaerobic <0) .4 Anaerobic a a a a ewe we we we we we ee se we we we we we we we ee ee ee a The hypoxic facies has been added to the Rhoads and Morse (1971) basin model by Dr. Barbara Welsh, University of Connecticut, to include responses of high metabolic rate demersal or benthic megafauna. ad _ - } iA 7 : [2 bene tne Avoctor I254) th Bosy aa - a 0 Re ee Se De ee ee Oe ee ee oat} cea a oe tr 2) 0,248 cTe A v, OBO cra gisossana $093 a Cc ’ 2 02328 2 “ = rar 2086 ¢ HLOMRAL LS : aa cara io . <3 #O0Nw/ 2 0. O94 ; he cOUMMY 2 : 0n.053— ee : Lone / 3 co.tngs 4 BOSS z | 046 sons /1 02415 | aT « 4008%,/2- 193 - - $005k’ 0,438 > pate ® .o19 re LSO0NM/ x . a, one s ; 34200 / > Pe F 7. ' 1S00Nws) ( >. 0064 ; 2.007 & 00m & r: a — ——— ——— _ a I — a 7 * balow Gets “se tm) || bait ' , ' D | 7 a ‘- *SUOTIEASsSLOWAU QUeseirde1 seTbuetz, ouL -a4TS Tesodstq uopuoyT MeN ey} We soeuetT AeaAans oTAjewAy Reg °[-z omnbtq NOCNO 1 MAN | *L86t Atne ‘a4Tts Tesodstq uopuoyT MeN 3yQ We (SeTHhuetiz3) suoT,eIS SLOWHY Jo suoTjZeubtsep pue suotjeso07T °@-@ eanbity [>_> |e. nn 2 a as en oa. ADSL ES ¢/8 ADDO “18 2/8 AgG2 V8 cL ADBS “V8 C18 ADSL “VB 2B 0.10404 SHOOT 08) _ 5 ee ane Asepunog ajis jesodsig N of NOSL "SI Ty JSOOh-9 GL ST Iy— Vv Vv Vv \/ \/ ASN08 v 3So0c-9 $S009-9 HS00C-9 MSOOh-9 J2u -NO'IN v7 ae ASOON-h| v v v ¥ if ASOOh v NBO “OT Ty v v v v Vv vil ISOOh-Z ysooz-z S00Z ##sMSooz-Z MSOOh-Z NOG DT Ty J000T e Vv Vv Vv Vv Vv Vv 3009 400h 5002 MO00Z NOOh aNOOZEZ MNOOZ-2 7 Vv INOOH-Z MNOOW-Z NOS? OT Ty HNOOH v WS? OT IF ANOOC-h MNOOZ-1 v Vv Vv Jou-aN / v ANODh-h NOOn Vv HOOK SUOI}EDO7 UOI}EIS *~NOCNOT MAN ABS? “V8 cLB AGES “18 210 “L86t Atne ’94TS Tesodstq uopuoyT MeN 34 3e suUOTReAS Usepinq Apoq pue AaAsTweyd jusUtTpes Jo uoTtTZed0T osULZ "€-2 oanbty NOIWLS AYLSIWAHO LNAWIGAS = 9 NOILWLS NAGHNd AGO = 4 Asepunog ayis jesodsiq NOSL "ST IY - AAW 3s008 34 Jey -NO'IN a ¢ a4 1OSc St Ty Se OT TF SNOILVLS AYLSINSHO LNAWIGAS GNV NaGuNnd AGO teh nc/*5% Vila hanen “2 NOONOT NAN el ee ee a —————— ES *siojou ut yydeq “286 Aine ut 93TS Tesodstq uopuoyT MeN oY JO AAeYO OTAQAOUAYAeq parNojUOD *T-€ eanbta NOSE ee 220 006" 76 220 MOGe* 76 220 M008*76- 220 MOSEL’ V6 220 HO006*86- 220 MOS2* S220 189 ay NOOO"ST TF fase" 91 tb -|- NOSe°ST Tb Asepunog ajis jesodsiq USO} Th -|- SS 2861 Aine HOSZ°E0 220 HO00°bO 220 HOSe "v0 220 M00S"PO eZ0 MOSZ°VO 220 *siejow ut yyAdeg -986t Atne ut e4TS Tesodstq UOpuoT MeN 9YQ JO RYAeYD OTAQZeWAYQeq perANOWQUOD °Z-€ oanbtg Host+Fer 220 i j No0s* V0" 2/0 NOt“ VO" 2/0 ie Nose’ KO 220 sJaqa}{ 005 00h O0€ O02 oof O -{y000°91 W NOS2°S1 Tp + Asepunog ais jesodsig —{N00S "91 Ty = a5 SBN re 9861 Ainr 07 ab NON MOSZ°E0 220 M0000 e240 MOGe" v0 ¢cZ0 M00S"P0 ¢cZ0 HOSZ° v0 220 Os 3 ( Wee suoTqeqS 3e WUSePTAS JOU SBM TeTAejeU pebpeaq ee TLTE iq peeery Keres — eouTS TeTe,zeMu JO UOTReTNUNDDe SY SMOYS SUTTINO peqjOp sy ‘“*saeeA Ased ut paytsodsep ATjuezedde [etzejZeu pebhpeizp sssoToue SUTT peysep syL *uqdep uoT}e193}0Ued ustid 24} pesoxe YOTYM srzeAeT TeTAsjZeu pobpeirp souejOeTJor MOT JO WUSRXe OY SQTWITep anojQUOD PTTOS eyL °zs86et Atne ‘94TS Tesodstq UuOpucT MON SYR 2e [TeTI9ReEU pebpeizp Jo uoTyAnqtTajAstaq °€-€ sanbty ABGS ED cB NOI LVYLINId WSINq NVH] YaxOTH] WIdALVY Gs9dsuq - + } Asepunog ais jesodsiq (WO) SSANNOTH] Wwiualvy as9qayg - # NOSL ST Th Jey -NOIN “ee Nase OT Ty SH3AV1 IVWIHSIVW Ga9dSud ~NOGNOT MAN Figure 3-4. REMOTS® image from station 200W ‘showing a typical dredged material layer which exceeds the camera prism penetration depth. This material is characterized by a distinct redox contrast and extreme low reflectance. Also note the amphipod mat at the sediment surface. Scale of image = 1X. Figure 3-5. REMOTS® image from station 2-400NE illustrating an apparent "relict" dredged material layer. This low contrast layer (arrow) has a maximum depth of approximately dab Cine. Seewle = ab< | | °"L£86t Arne ‘aqTS Tesodstq uopuoyT MeN ey 3e (sqtTUuN TYyd UT) epow AOCew ezTSs uTeIb Ausutpes jo dew °9-€ oaNnbTA Abus ED 2/0 AOSL “V8 2/8 @.440}| 009 MOS Or ME Ke BOT DB Ss S——"— Asepunog ajis jesodsig N of any YaAQ GNYS - W/S —NOGL ST TY MSL ST Ip JSu -NOTN xe £-h< spucs aul4 pue aul4 Ala, JOU-M S-hy ” 1GS2 OT Ty (swun ud) BPO JOle/\ 9ZIS UleI "S"NOCNOT HEN AUG E 20 ROSL "ED 220 Ao00 "V8 220 AOG2 V8 2/8 AOS “VO 2/0 SN eT a (ec eee ee eee Figure 3-7. A layer of fine sand overlies silt-clay in this REMOTS® image from station 4-200NE. The sand layer may reflect inputs of coarse- grained dredged material. Scale = 1X. 56 HEW LONDON 45 AULY 1987 F = Rk 3 = 3 = 114 les gs E < N 5 (De c= oy KEY 1 aE Class Range of Boundary Interval Roughness (cm) iu aes interval ‘Roughness (em) _ 2 0.6 - 1.0 BOUNDARY ROUGHNESS CLASS INTERVAL 3 1.0- 1.4 4 Low 2 bof 5 Io} © Doz 6 Ao 2 Boe 7 2.6 - 3.0 8 3.0 - 3.4 9 S355 > -SJofe! NEM LONDON REFERENCE = ane BOE BEC 12 4.6 - 5.0 F E G N = 18 U E H C | 1 Ltt 3 18 BOUNDARY ROUGHNESS CLASS INTERVAL Figure 3-8. Frequency distributions of small-scale surface boundary roughness values for all replicates at the New London Disposal Site and reference stations, July 1987. “wo O°€ > SUAdep day ebezoeae HutAtqtyxs suotjeqAs ouy JO SUTTINO By MOYS SSUTT PTTOS SsuL “L86T ATUL ‘84TS Tesodstq uopuoyT mon ayy ze ‘uot Zeq4s Aq pebezoae ‘(uwd) syjydep qqu juezedde jo uot{Anqtazqstp euL "6-€ oanbty ABSL “VA 20 809 Aisepunog ails jesodsig N Vv NOGL'ST Ty Jey -NOIN x“ 8°h Jou-M 6Sv Nose ‘OT Ty joan {7 0S (Wo) Hidad ddu jugueddy O'Gy MN OOST NOUNG | MAN ADS? “WB 21D NEW LONDON JULY 1987 iG NEW LONDON REFERENCE JULY 1987 F N = 16 R E G 20° 5 Nl L ¥ @ I... _.4_.F tl oa... 4) 1 2 3 4 3 6 7 & MEAN RPD DEPTH ¢CM> Figure 3-10. Frequency distributions of apparent RPD depths for all replicates at the New London Disposal Site and reference stations, July 1987. exe} II obeys Hbutyoe[T severe AIWTTep sanoquoo ey, -juesertd jou oezem exe III e6e3S eteyM uoTIeAIS STHUTS 9YyR SeqeoTpuT HuTYyoReY oyL “L86T Arne ‘eATS Tesodstq uopuoyT MeN oy} 3e sebeqjs [euoTssadons [TeunejsUuT JO uoTANqTAASTp eUL *TI-€ eanbry ABOS iF ri) ABS Tp 4b) 6.1044} BOO MOS Boy ME A Aisepunog ais jesodsiq N v NaSL ST Ty— NOSL “SI Ty Vv Vv Vv Vv Vv | e6e1s JOu -NOIN We Nod BT Ty is ¥ Nod "DE Ty — | BHe1S uo | abeys Vv Vv Vv Vv Il aBeyS Il] 861s uo | eBeis you-m eal Vv Vv NwS2 OE Tr abe1S JeUOISSBDONS ill eBe1S uo || aHe1s ™S"NOGNOT NAN ANS? “18 218 ADDS “VB C18 Figure 3-12. A dense assemblage of tube-dwelling amphipods is visible at the sediment surface in this REMOTS® image from station 2-200NW. These amphipods occur throughout the New London site, usually together with Stage III taxa. Also note the hermit crab. Scale = 1X. *286T AtTnec ‘94TS Tesodstq uopuoT men ey} 3e ‘uoTZeA3s Aq pebereae ‘sSeoTpur AueuTpes-usTuebh1zo Jo uoTANqTAASTp oeUL "€T-€ eanbry Asepunog alts jesodsig NOGL ST Ty Jou -NO'IN xo It sore XSGN Ty LNAWIGSS WSINVOYO IT oN MN OOST “ NOGNOT MSN NEW LONDON JULY 1997 59 F R E G U E N C 9 Clpesk optic ons Ghatsrea? efzme Sle l(sierhs| ORGANISM-SEDIMENT INDEX 15 NEW LONDON REFERENCE JULY 1997 R eet F N = 16 U E t Y 5 gl... eee | 3.6 7 § 21811 ORGANISM-SEDIMEHT INDEX Figure 3-14. Frequency distributions of Organism-Sediment Index values for all replicates at the New London Disposal Site and reference stations, July 1987. (meters) Depth LOR 2 Avaie AS 20) (fea eae Figure 3-17. A CTD/DO plot obtained at Station 400W on 27 July NLON 400W Dissolved Oxygen (mg/1) OOOO 0 e 4 6 8 10 axOOOOeeeeeeEeEeEeEeEeEeEe—e—e——————————EEEEEE Signage =erts 18 wus 20 a4 22 ea Sa lanaty y (ppm) sexxx*x 27 28 29 Temperature (C.) 16 a7 18 49 20 O41 aK 4 x ok oi OIC FOI CIICIOKIORIOIORI IO IOKIORIOK AK AAG AA gate 0 1987 (meters) Depth NLON 4-400NE Dissolved Oxygen (mg/1) 0000 0 2 6 8 Sigmesi Se saat 18 19 20 21 ee (Z| J_ Salinity (ppm) xxx 29 o7 28 SiO) Sh 4h 32 Temperature (C.) XXXX 16 47 48 49 20 ef 0.0 +4 *xK 8 8 et ¥+ 2.5 8 ¥ oe aA sR QO | E+ at AS 8 ca 8 8x” pe ae o.4 * + 10.0 xB eae x 6 cy as x 8 es x * + 12.5 = g m8 x 8 é f x O x 15.0 ae |: i x O * + 17.5 : : : f 20.0 22.5 25.0 Figure 3-18. A CTD/DO plot obtained at Station 4-400NE on 29 July 1987. ro) an) raul o = fav] ™ 4 + OR xX y. x + xx + x +E geroar Oo a m 2 x age + tte eee ® ae fo) #t + + ++Het+ + * < * < KK a * < rc x< SS + * Le (@)) + Lu Ew tx 2) —~O (ac Wi + 0 =) 2 Sal = (o) ! e rol — = a) kK (ou 'e)) | = w > (e (= Z x e > =) yy Oss Ae a2 fal GE UD Ww (= ress iad) “4 rab) > 4 iol oat (0) e oO Ww i) 9) i 9) -4 o ae) Ta) QO =I fall <4 ro) @ ~ Te) I fall = (SUa}aW) YUIdaq A CTD/DO plot obtained at Station W-Ref on 29 July 1987. Figure 3-19. (meters) D2janeln 10 12 AT 20% eon ear i | Ae NEON NES Re Dissolved Oxygen (mg/1) oO000 0) 2 4 6 8 10 J]_ A S)atle(isl= 1p arses 18 49 20 21 22 23 a Salinity (ppm) %*xxx 27 28 29 30 34 32 BiHempena Gane (Ge ie XXXX 16 20 21 Figure 3-20. A CID/DO plot obtained at Station NE-Ref on 29 July 1987. ” (wid) 6H SORA gy APPENDIX I (meters) Depth ACOSO) 27 / 87 Dissolved Oxygen (mg/1) OOOO 6) e 4 6 8 SHG Mice ll Stated 18 19 20 ed eo 23 Temperature (C.) XXXX 18 49 (meters) Depth 4-—AQ0 SW 007 727787 Dissolved Oxygen (mg/1) OOOO 4 6 8 0 2 10 SigGtidea ll fttt 18 419 20 e1 22 e3 Salinity (ppm) *xxx 2 7/ 28 2g 30 Sp 32 Temperature (C.) XXXxX 16 17 18 19 20 24 (meters) Depth 10. 2 NS) « ie AO) e ee. ear 4-400SW 07/27/87 Dissolved Oxygen (mg/1) OOOO 4 6 8 0 e —————— ee SHigMas i era 18 19 20 24 22 23 ee ee ey Salinity (ppm) %*xxx 27 28 29g 0 XXXX Temperature (C. 8 JGR RICHI RIOR OK 2K * ++ yt seeick yoceHsIo SR HEHEHE HE eH + + OO Gay sven: 00 0 O@OD00DdDooomp @apo “HEE +4 (meters) Depth A-AOOSEGO7 A27737 Dissolved Oxygen (mg/1) OOOO 6 8 SmgMate lta 20 en ee 23 Salinity (ppm) %*xx*x 2g 30 Temperature (C.) XXXxX 18 49 BOCEBON/ 27787 (mg/1) OOOO 6 8 40 4 Dissolved Oxygen 2 ea 22 19 18 (Dpm) *xXxXx Salinity Sj 29 27 =i cu a ecleclao). 000 Feary x< COSCADAGOAMD 0000 ap oapan, aman = ba atte. +t tt COgnn00Gas0 eet hte POE . = + ne : on x +0+ nol eee cal O ‘ab) a 5} oe) i 2 e a) a i= w k- 07, 20 ee. 25 (SUaqzaW) UIdaq SB. 200SE 907 727737 10 0000 8 (mg/1) 6 Dissolved Oxygen 4 2 es 22 18 ge (ppm) %*xXxx Salinity 2g 27 eu Temperature 18 197, te) iss Te} ro) Te} ro) Te) fo) Te) ro) Te) ro) ro) cu Te) ~ ro) cu Te) ~N >) raul Te) I — <4 = cu fal) Ou (SU8qzawW) UIdsaGq (meters) Depth 6-400 SE4077/ 27787 Dissolved Oxygen (mg/1) OOOO ) 4 6 8 ee cn oe SaMouMlels lh aearagas 20 18 AS 21 22 eo Salinity (ppm) %*xxx 29 Temperature (C.) XXXX 48 9 (meters) Depth BOOSE©OYfAe7 787 Dissolved Oxygen (mg/1) 0000 2 4 6 8 J] SGMeg tata 20 18 ile) 1 2e 23 Salinity (ppm) *xxx 29 Temperature (C.) XXXX 48 419 LOOORROW/ 27 / 87 (mg/1) O0O00 6 8 40 4 Dissolved Oxygen e eS ++++ 22 21 Sigma-T 20 18 (ppm) xxx Salinity 3 eg 28 27 Temperature 18 17 (SUazaw) yidaq 2O00N 07/27/87 (mg/1) O0O00 4 B 10 Dissolved Oxygen 2 SaGtes | at 20 eal ee 23 i 6 de KRKX 30 31 (ppm) Saulsainaitey. 2g 28 27 24 OTD OD GRGIASIF 499-44 aaMaKch cbebetitichcs 4+ feet yore OK 10K SRORIIOK IOOK OK OKIORIOK OKO REKCOK ~ O) tt Hye iio k* O RK ® jen >} aw) (© [je ® [oy = ® Kk Sie a os KOK 100) a 4OOO< AK KKK XK OHO 9 909K (SU8}SaW) UAdaq (meters) Deaicin 2OOWNOW/ 27 787 Dissolved Oxygen (mg/1) OOOO 0 2 4 6 8 10 SSS SSS SagMas tt 20 18 sls) eal 22 es Salinity (ppm) %*xxx 29 27 28 30 Sal 3\2 Temperature (C. 48 10 (ae 32 0000 8 22 (mg/1) 6 4 SugMasl et en (ppm) 2 COOSWOY 7 277 87 Dissolved Oxygen 20 Sa lanaby 29 2 19 28 18 Zi Salons) O@DO GDGDOOO G0 OaDOQ yy + x ponratrega! ee ++ x att SOCRQ TRH pager Tt yok OK RK > +++ tan JOIIORIK RORISIOK ZO f++% pK sono us) ORK ARIA QO eR x q) SOK MOK $00 = 3 oe) ol a Cc w fol = eb) IF ~N =i Te) <= (SUaqZaWw) UAdsq (meters) Depth 2-200NW 07/27/87 Dissolved Oxygen (mg/1) OOOO 6) 2 4 6 8 10 SiG Masai = ttt t 18 49 20 24 22 23 Salinity (ppm) x*xxx 27 28 29 30 Shal 32 Temperature (C.) XXXX 18 49 KK —~«x>x REI KK IORS PRK 06 eH ed, So OR RRO 11 OK 2K OOK K KHOOO0OK OKK pe Heb tet ty tt + + OD 0000000000 000 caMDGCCDO cOOEREOOOg, (@) ™m fav] = S) bt beat HH Eta + te tt et ta tt on a =a C718 t # 2 = i °0@ 0 09 = eee ene ORK OK RIK OK KEK KOKO git KOK OK Zio ato x x 77° * $ com o am oom © ®@ 0000 O@ 008000 m 2 xe a ‘chi * OO = ats * aah + se A ar +a] —.™ _ er calael iS i oO wm x (S (ol, 3 O ey | = rab} %. > © C x (S) '@)) p vp x O Ort sey ahy Be .: oO U Ww) Cc (e 5 00) @ “4 i) dp) {j= ‘ a Oo) @ N x AO Wages (a) a fa “4 WX XR x xx ex XI 50 OOK oO io) ~ =i fal] (Suajzaw) Uydaq ROOOSMOR7 29/737 (mg/1) OOOO 6 8 40 4 Dissolved Oxygen 2 eo 22 1S 18 KKK 30 (ppm) Sie] Ih a gyauicwy, 2g 27 + + ee tet tet tah t+ ter + + ‘'B. O@BO OMMDO GO WD x oapk 2K aK OK RMCK ME OK OK aK ak POR mK ++ ++4FO Oamp OGD OGMmO a@®OO a ©0@o0 oa gq e+ tee *K a e xX X $6 x x Ne sm, a x Temperature 48 x 17 >. OF x ogo. WX x GK a XX XI, x (SU8z9W) YAIdSaG (meters) Depth AQON CODZES7 87 Dissolved Oxygen (mg/1) OOOO 6 8 Sigtidel itt 18 19 20 pl ec 23 yt Salinaey oppme %*«xx 2g eu, 28 30 Slal S\2 Temperature (C. (meters) Depth 4—-4OONW 07/29/87 Dissolved Oxygen (mg/1) OOOO 2 4 6 8 p_ SCE] aarsrae 20 18 AUS) Za Ze 2S Salinity (ppm) %*xxx 29 30 an 32 Temperature (C. 18 (meters) Depth C5OGNWROZA2L97 87 Dissolved Oxygen (mg/1) OOOO 6 8 SENGIN@E 1. Sheath 18 49 20 24 22 23 Saliinateyr Alp pm)! sexee%x 27 28 29 30 24 32 Temperature (C. (meters) Depth NECN Rem 077297 87 Dissolved Oxygen (mg/1) oo0o 6) 2 4 6 8 10 tH SGM ae htt 18 19 20 241 22 23 Salinity (ppm) x*xxx 27 28 29 30 Sil Se a Ss cee lemperatuyrme (G.) Xxxx 9 v U. S. GOVERNMENT PRINTING OFFICE: 1990--700-017--00036