Contribution # Yar (98 | Seasonal Monitoring Cruise At The Western Long Island Sound Disposal Site August 1986 | Disposal Area Monitoring System DAMOS re iS | DES: no. b| Contribution 61 March 1988 DOCUMENT LIBRARY Woods Hole Oceanographic Institution US Army Corps of Engineers New England Division - UTICA MBL/WHOI A 0 0301 0069523 5 SEASONAL MONITORING CRUISE AT THE WESTERN LONG ISLAND SOUND DISPOSAL SITE AUGUST 1986 CONTRIBUTION #61 11 JANUARY 1988 Report No. SAIC - 87/7500&C61 Contract No. DACW-86-D-0004 Work Order No. 2 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 Naik ean i TS ee ee a oe ‘yes a a > = ; a E ® UG 2, | (H+ i _ Se! Ona ae ’ P44 4% ( ' ae Y ‘ j { athe -% : +% . a 2 ‘ wy ‘ ees Hee? Me Ae ait 5 Aaya 8 » eat ia a, ytd ( ' ce , i ) ce ¢ H yx: \ ia < 1. i m 7 ;

4 phi) sediments (Figure 3-3). However, a cluster of 6 stations on and east of mound "C" consisted of very fine, fine, and medium sands. Figure 3-4 shows the distribution of sandy sediments across the survey area. Distinct sand layers, either at the surface or buried, were evident throughout the northern and eastern half of the region (Figure 3-5). Mounds "A" and "B", composed predominately of silt-clay, also exhibited some near- surface layers of sand. Based on this distribution, the sands appear to represent dredged material deposited since the last complete survey of this area in August 1985. This inference is also supported by the lack of sand layers in images from the western portion of the survey area and from the WLIS Reference station. All replicates collected at the WLIS Reference station exhibited a major mode of silt-clay (> 4 phi). Dredged material layers (Figure 3-6) deposited since 1985 were readily detected when dredged material thickness was less than the prism penetration depth (20 cm). This was because the relatively high-reflectance, pre-disposal interface was evident below the low-reflectance dredged material (Figure 3-7). This high-reflectance material could be either natural bottom or previously deposited dredged material that had developed a deep RPD layer. The pre-disposal interface was not evident in many of the images from the region around disposal mound "C" indicating that dredged material layers were at least 20 cm or greater throughout this area. Overall, dredged material was widespread in the area surveyed. Only the southern portion of the site lacked readily discernible dredged material layers. At the Reference station, thirty-five percent (7 of 20) of the images showed subsurface low-reflectance layers overlying high-reflectance sediments. These layers do not sharply contrast with adjacent sediments and are generally discontinuous. They are inferred to represent relict dredged material (i.e., material disposed of a number of years ago). Recently deposited dredged material would be expected to contrast more sharply with the buried pre-disposal interface. Similar dredged material layers were observed at the Reference station in 1985 and 1984. At those times, it was also concluded that this material represented relict dredged material deposited in an historically-used disposal site in that area (Eatons Neck). REMOTS® images were not obtained at the WLIS reference site prior to 1984. A process map of the survey area shows the distribution of features which are indicative of bottom disturbance (Figure 3- 8). For example, many stations showed the presence of low reflectance (black) sediment at, or near, the sediment surface. This reduced sediment appears to have its origins from below the high reflectance (ferric hydroxide) bioturbated zone as either a layer or discrete mud clasts (Figures 3-7 and 3-9). Oxidized mud clasts were also present in many images. Surface patches of reduced sediment (which were also observed in the August 1985 WLIS survey) were likely produced by predator excavation and/or bottom scour. The depth of excavation or scour need not be great to expose this reduced material to the interface because RPD depths are shallow (< 2.0 cm) over much of the area. Methane gas pockets were observed at depth in the sediment at station 3-D (Figure 3-10). The presence of methane is an indication of high sediment oxygen demand (SOD). Surface shell lag deposits, produced by physical bottom scour, were observed in 5 images. In general, evidence of small-scale physical and biogenic bottom disturbance was widespread. This is similar to the pattern observed during the post-"Gloria" REMOTS® survey in October 1985. The relative frequency distributions of surface boundary roughness values at the WLIS survey area and WLIS Reference are shown in Figure 3-11. The major mode was 0.80 for both regions. This represents an increase in small-scale surface roughness since August 1985 when the major modal value was 0.4 cm. This may reflect the impacts of Hurricane Gloria on the region. The mean apparent Redox Potential Discontinuity (RPD) frequency distribution for the survey area (Figure 3-12) is bimodal with modes centered at 1.0 cm and 3.0 cm. The mean RPD depth was 2.16 cm. The WLIS Reference RPD distribution is skewed right with the major mode at 1.0 cm, and a mean value of 0.59 cm. RPD depths at WLIS Reference were significantly shallower than RPD depths at the survey area (Mann-Whitney U-test, p < 0.001). This pattern is noteworthy and suggests that the "disturbance" factors affecting the WLIS Reference station were more severe than the effects of the dredged material disposal operations occurring within the WLIS survey area. At the WLIS survey area, RPD depths have shallowed significantly since August 1985 (ANOVA, p = 0.004); suggesting an increase in oxygen depletion in the region. The mapped distribution of mean RPD depths is shown in Figure 3-13. The hatched areas exhibited RPD values greater than 3 cm. In general, these areas were restricted to the edge of the survey area. Most of the region was represented by RPD values between 3 and 1 cm. Based on past experience, values less than 1 cm represent highly stressed habitats. The largest highly- stressed area extended N-S through the area occupied by mounds rane! a this likely cetlects the antluences wor scecent disposal operations. Another area of low values existed adjacent to mound "B". The location of the three disposal mounds appears to "straddle" regions of both Stage I and Stage I-III successional seres (Figure 3-14). Stage III seres occurred in three large patches in the eastern, southern, and north-central portion of the survey area. G€ompacison of Figures 3-14 and 3-1/3, nevealisiva poor correspondence between Stage III seres and deep RPD's. This pattern may indicate that a retrograde successional condition was being caused by reduced rates of bioturbation (possibly due to seasonal hypoxic conditions). About half of the WLIS ‘survey area stations and 70% of the WLIS Reference replicates exhibited a Stage I assemblage. Again, this pattern suggests that, overall, the WLIS Reference station was more highly stressed than the active disposal area. In August 1985, the distribution of Stage III seres was much less widespread in the eastern portion of the region. Based on the results of past REMOTS® surveys, Organism- Sediment Index (OSI) values of +6 or less are considered to indicate that the bottom is stressed or has experienced recent disturbance (erosion, dredged material disposal, hypoxia, or demersal predator foraging). The polymodal OSI frequency distribution of the WLIS survey area (Figure 3-15) indicates a mosaic of past disturbances (the major mode at 6 and 7, subordinate modes at 3 and 9). The WLIS Reference site had a major mode at -3, and no values exceeded +5. OSI values for the WLIS survey area were significantly greater than the WLIS Reference OSI values (Mann-Whitney U-test, p < 0.001). Even relative to the WLIS survey area, WLIS Reference appeared to be a highly stressed region. The mapped distribution of OSI values (Figure 3-16) shows a region of relatively high OSI's to the east of the site and to the north and west of the disposal mounds. The apex of disposal mound "B" exhibited relatively high, but variable, OSI's. Mound "A" was bounded on the south by an area of high indices. The center of mound "C" was associated with the lowest mapped OSI value (-2); this illustrates the impacts of recent disposal operations. The overall pattern of OSI values consisted of high and low values in close proximity to one another. This appears to reflect both the influence of disposal operations as well as disturbance factors (unrelated to disposal) prevalent in western Long Island Sound in general. 3.53) Sediment Characteristics Results from the chemical analysis of the sediment samples are presented in Table 3-1. Each individual result and the means and standard deviations are presented for the Top and Bottom sections of each core. The exception to this is PCBs for which only one composite sample was analyzed from each station. Statistical tests were performed to determine if the contaminant concentrations were different between stations. 8 Also, the contaminant concentrations of the Top and Bottom sections of the cores were compared. The Kruskal-Wallis test was used for comparing concentrations to detect significant differences at the p < 0.05 level. Results of the statistical analyses showed that in the cores from the Reference station, the concentration of chromium was significantly higher (p<0.05) in the Top sections whereas those of iron were significantly higher in the Bottom sections. In the WLIS-A station cores, concentrations of lead, nickel, copper, and oil and grease were significantly higher in the Top sections compared to the Bottom sections. The concentrations of these same four elements were significantly elevated in Top sections of the WLIS-A cores compared to those of the Reference station cores. The physical characteristics were determined for the sediment collected for the benthic community analysis (Table 3- 2). The sediment from all five samples obtained at the "A" mound center was described as dark gray silty sand with some gravel and/or shell fragments. The sediment from the Reference station was much finer material dominated by dark, olive gray organic clay with shell fragments. 3.4 Benthic Community Analysis The sieve residues from the Reference station samples consisted of 500-1,200 cm? of shells and shell particles. Intact shells of bay scallop (Aequipecten irradians), soft shell clam (Mya arenaria), gem clam (Gemma gemma), juvenile surf clam (Spisula solidissima), and mud snail (Ilyanassa obsoleta) all suggest an origin in shallow sandy bottom. Coot clam (Mulinia lateralis) shells were also present, but are less indicative of (poate yaligye The samples contained a small amount (approximately 20 cm’) of fine organic debris. Samples collected at the center of "A" mound contained 3000-4000 cm’ of sand and pebbles and about 100 cm? of coarse plant debris. Smooth white quartz pebbles were a conspicuous constituent. Bits of coal, boat paint, and rust could be seen under magnification. Table 3-3 presents the visual descriptions of the sediment grabs collected at both WLIS-A and the Reference station for benthic community analysis. Species counts are given in Table 3-4. A summary of the number of species and individuals in major taxa at each station is given in Table 3-5. The number of species present at the two stations follows a pattern found at other disposal sites. Species richness is lower at the Reference station than at the WLIS-A station. At both stations, polychaetes were the most abundant taxon followed by molluscs and crustaceans. Density of individuals was higher at the WLIS-A station than at the Reference station (mean/sample 1421 vs. 584, Table 3- 5s Most of the individuals at the WLIS-A station were polychaetes with a mean density per sample of 1264 (89% of the individuals). There were nearly equal numbers of polychaetes and molluscs in the Reference samples. Crustaceans were found at low densities at both stations (2.2 and 2.3% of individuals). The dominant species at the WLIS Reference station are characteristic of the deep silty bottoms of Long Island Sound. The polychaetes Nephtys, Mediomastus, Sigambra, and Cossura; the bivalves Nucula and Yoldia; and the anemone Ceriantheopsis all also appear in samples collected at the reference station at the Central’ Long “island )Sound =(CLis)) = disposalmmsiter Excluding Mediomastus, these species were absent or found in lower numbers in the WLIS -A station samples. The densities of dominant species at the WLIS Reference station were less than are usually found at CLIS and included few mature individuals. The WLIS-A station had over 20 species which were notably more abundant than at the Reference station. These included species requiring solid surfaces for attachment (e.g., the polychaete Sabellaria, the gastropod Crepidula) and many tube dwellers or burrowers requiring silty sand or sandy substrate (e.g., the polychaetes Pherusa, Pectinaria, Euclymene, Ampharete; the amphipod Leptocheirus; the bivalves Ensis, Tellina). In addition, some species present are characteristic of shallower, less saline, more variable environments (e.g., the polychaetes Polydora ligna and Nereis succinea). 365) Body Burden Analysis Triplicate samples of Nephtys incisa from both the WLIS-A and Reference stations were analyzed for eight inorganic elements and several PCB formulations. Concentrations were calculated on both a dry weight and wet weight basis for comparisons with literature values and FDA action levels. Statistical analyses (Kruksal-Wallis test) were conducted on the results to test the difference between concentrations found in organisms collected at the two stations, with the exception of PCB's which were below the analytical detection limits. Results of the inorganic analyses are presented in Tables 3-6 and 3-7 and the PCB results are shown in Table 3-8. The results from the statistical analyses of the inorganic data showed that the concentration of lead in the Nephtys collected from the WLIS-A station were significantly higher (p<0.05) than in those collected from the Reference station. Zinc and cadmium concentrations were significantly higher in the Reference Nephtys compared to the levels in the polychaete collected at the WLIS-A station. 10 4.0 DISCUSSION 4.1 Bathymetry Results of the bathymetric surveys conducted at the WLIS disposal site indicate that dredged material is accumulating at the designated disposal point between mounds "A" and "C". The volume of deposited dredged material estimated from scow logs was 73,230 m?. The volume difference calculated from the bathymetric surveys in October 1985 and August 1986 was 35,700 + 6720 m3, or 49% of the scow log estimate. The difference in the two estimates is partially due to the overestimates from scow logs due to unknown amounts of water in the scow. In addition, dredged material at the flanks of the mound can occur in thin layers that are undetectable acoustically. Finally, compaction Oth ewemat-crmialsOnuethenmbotcoms spislom) «cols the = post—disposal: bathymetric survey can significantly affect the estimate of the volume of deposited material. A study was conducted by the New York District of the Corps of Engineers in 1980 at the Mud Dump Site in the New York Bight to determine the loss of dredged material from the initial dredging to disposal (Tavalaro, 1983). A comparison of carefully determined volumes of dredged material in the scows with the volume of material deposited at the disposal site, determined by pre- and post-disposal bathymetric surveys, indicated a loss in volume of approximately 40.7%. Of this total, a volume loss of 15.4% was attributed to the dispersal of interstitial water during descent. It also has been estimated that approximately 7% can be attributed to compaction of the material once on the bottom (Bokuniewicz et al., 1980). Bokuniewicz et al. has determined that 50% of the total compaction will occur within one month of disposal and 100% within one year. Of the total loss in volume of 40.7% determined at the Mud Dump Site, approximately Cero cue (Olsud Ol cane e142. o))) Or the loss sanwavolume: awas unaccountable. This loss is likely due to dredged material being deposited in thin layers that can't be detected acoustically. 4.2 REMOTS® Sediment-Profiling The major objectives of the present REMOTS® survey were - to document the distribution of dredged material in the WLIS survey area and to document the process of recolonization on the new and existing disposal mounds. As observed in the surveys conducted in 1985, dredged material was widespread in the surveyed area (Figure 3-6). Dredged material layers were distinct and relatively thick, often consisting of coarse-grained sediments, in the eastern portion of the survey area and apparently represent materials deposited at the present disposal point since the last complete REMOTS® survey in August 1985. This dredged material may extend somewhat east and northeast of the area surveyed. However, because the survey area was 11 approximately 1600 meters west of the eastern boundary of the WLIS Disposal Site (Figure 2-1), this dredged material is likely contained well within the disposal site. In general, the dredged material observed in the western portion of the survey area was fine-grained and did not exhibit a sharp contrast to the surrounding sediments in terms of its reflectance and many of the layers were discontinuous (Figure 4-1). This "weathered" dredged material apparently represents sediments deposited in past years (Qe pointsmwANwandewBw)r Dredged material was also detected in 35% (7 of 20) of the WLIS Reference images. In August 1985, dredged material was observed in 50% of the Reference images. Based on its very low- contrast optical signature and discontinuous layering (Figure 4- 1), this sediment is inferred to represent relict dredged material. The Reference station is located near the edge of an historically-used disposal site (Eatons Neck). These inferences regarding "relict" dredged material are further supported by the lack of sandy sediments at the Reference station. Sands were concentrated only around disposal point "C". Based on scow logs, this coarse-grained material represents the most recently deposited material. The placement of the WLIS Reference station near a previously-used disposal site (Eatons Neck) is the unavoidable result of several constraints encountered during station designation. These constraints included locating a station near the WLIS Disposal Site of comparable water depth, bottom topography, and sediment type. In addition, several formerly used disposal sites are present in the region. Consequently, an area satisfying the above environmental criteria that did not occur in or immediately adjacent to an historic disposal site could not be found. Some infaunal recolonization of the survey area has occurred between the 1985 and 1986 surveys. Stage III taxa were more widespread in the region of the active disposal point in 1986 (50% of the images) than in 1985 (33% of the images). Overall, however, OSI values in the WLIS survey area have not changed. Moreover, RPD depths across the survey area have become shallower since 1985. This change appears to reflect bottom- water oxygen depletion. Near-bottom hypoxia was prevalent throughout much of the Sound in August 1986 (this is discussed further below). This is the second REMOTS® survey at the WLIS disposal site since August 1985. The previous survey was conducted in October 1985, one month after Hurricane Gloria. This post-storm survey was concentrated on, and around, the three disposal mounds. The post-storm survey indicated that massive sediment transport or erosion of existing mounds did not occur. However, many stations experienced surface erosion which was deep enough to strip-off the aerated surface and expose reduced sediment to the water column. This phenomenon caused a major downward shift 12 in Organism-Sediment Index Values. Table 4-1 compares the WLIS data collected during the present survey with data collected in the October 1985 post-storm survey. There is no difference in mean RPD depths for the WLIS stations, but OSI values in the present survey are significantly higher than those measured after the -hurricane. This pattern indicates that the infaunal successional stages of the survey area have improved since October 1985. Table 4-1 also compares the WLIS Reference station, as measured in this survey, with the data collected in October 1985. Notably, mean RPD depths were shallower and OSI values were lower at WLIS Reference station in 1986 than in the disposal area after the storm. The highly "stressed" conditions that presently exist at the WLIS Reference station are not readily explained. Near- surface reduced sediment patches were evident in all the References images; this feature suggests disturbance of the bottom (e.g., predator foraging or trawling activity). IMS » aS known, also, that severe bottom water hypoxia was widespread throughout western Long Island Sound at the time of the survey. In August 1986, a REMOTS® survey was conducted in Long Island Sound from New Haven, Connecticut to the Throgs Neck Bridge (SAIC, 1987). This survey, funded by EPA Region I, was conducted to characterize the dissolved oxygen conditions within 1 cm of the sediment surface over the entire area. A YSI digital oxygen meter and the YSI probe were mounted on the REMOTS® camera such that the probe membrane was 1 cm above the sediment-water interface. Five replicate images and dissolved oxygen measurements were made at each of 45 stations. One of these stations was located near Station 4-A of this survey (40°59.33N and 73°29.503W). The five replicate dissolved oxygen values were: 1.88, 1.90, 2.40, 1.84, and 1.80 mg/l. These values fall well below the Interstate Sanitation Commission's water quality standard of 5 mg/l. Similarly low values were found in deep water (generally > 15 meters) over the entire surveyed area (from Throgs Neck to New Haven). This hypoxic event was certainly a major contributing factor to the stressed benthic conditions observed at the WLIS survey area in 1986. This event does not explain why the WLIS Reference station was disturbed relative to the WLIS disposal region (both areas lie below a depth of 15 meters). However, it is apparent that the most severe ecosystem stress affecting the western Long Island Sound benthic environment is not directly related to disposal activities but to Sound-wide bottom hypoxia. Since the initiation of REMOTS® monitoring at the WLIS disposal site (1984), shallow RPD depths have been observed. This suggests persistent or recurrent hypoxia in the western Sound in recent years. Accurate spatial and temporal mapping of this event and research into the possible causes will become an active area of investigation over the next decade. It will be critical to incorporate the findings of this research into the long-term assessment of the impacts of dredged material disposal in Long Island Sound. 13 4.3 Sediment Characteristics Sediment chemical analyses were previously conducted at the WLIS-A disposal mound during June 1984 (SAIC, 1985) and August and October 1985 (SAIC, 1986b). The October sampling and analysis was done to determine the effects of Hurricane Gloria. The Reference station was previously sampled during June 1984 and August 1985. Comparison of the chemical concentrations measured in the Top core sections with those measured in the Bottom sections revealed that certain elements did exhibit higher concentrations in the Top core sections. For the samples from the WLIS-A and the Reference stations, lead, copper, nickel, and oil and grease were significantly higher (p<0.05) in the Top core sections. In addition, chromium was also significantly higher (p<0.05) in the Top sections at the Reference station. The reason for the elevated concentrations of those particular elements is not readily discernible at the present time. More intense sampling would be needed to accurately determine the actual relationships of the metal concentrations in the sediment. When the sediment chemistry from previous samplings at the Reference station are compared to the results of the present sampling there (Table 3-1), the following can be concluded. The concentrations of most parameters measured in the present study are similar to those previously measured at this’ station. Exceptions to this were mercury and PCB's which showed Significantly higher concentrations in the present survey and the Chemical Oxygen Demand which was lower. At the WLIS-A mound the measured concentrations reported in Table 3-1 are again generally very similar to what has been previously reported (SAIC, 1985, 1986b). However, the concentrations of mercury, lead, chemical oxygen demand, and PCBs are significantly higher than the previously reported values. Other studies have reported the concentrations of metals and PCBs in Long Island Sound sediments (Table 4-2). Benninger et al. (1979) measured the concentrations of lead, zinc, and copper in a sediment core collected in Central Long Island Sound. The zinc concentrations that they found ranged from 106-190 ppm in the top 10 cm of the sediment core. These values are very similar to the concentrations at both stations in the present study. The copper concentrations reported by Benninger et al. (1979) ranged from 44-96 ppm, again similar to the results reported here. Lead concentrations were 30-52 ppm. These levels are similar to the Reference site concentrations but lower than the levels reported at the WLIS-A mound (Table 3-1). Similar levels were also reported by Greig et al. (ale\7/7/)) alig\ qela@ 14 area of the Western Long Island Sound Disposal Site. fTherefore, the lead concentrations on the WLIS-A disposal mound are somewhat elevated over those of other sediments in the vicinity. Greig et al. (1977) also measured the concentrations of nickel, chromium, mercury, and cadmium (Table 4-2). They measured nickel concentrations between 22.0 and 22.6 ppm in the vicinity of the disposal site. These are similar to the values measured for both sites of the present study. The chromium concentrations that Greig et al. (1977) reported were 159-164 ppm which were higher than the levels measured at both the WLIS-A and Reference stations in this study. The mercury concentrations that they reported were 0.5-0.6 ppm. These levels are similar to those from the present study and previous studies at the Western Long Island Disposal Site (SAIC, 1985). Cadmium levels were below the analytical detection limits of the Greig et al. (1977) study. Munns et al. (in preparation) reported cadmium concentrations in sediment from the Reference station of the Central Long Island Sound (CLIS) Disposal Site to be near 0.3 ppm. This is considerably lower than the levels reported in the present study. The iron concentrations were similar in both studies. Munns et al. (in preparation) also measured PCB concentrations. They reported levels ranging from 0.03-0.05 ppm in Reference sediments. In the present study the concentrations were 0.09 at the Reference site and considerably higher (0.50) on the WLIS mound "A". 4.4 Benthic Community The uniform, fine-grained, soft sediments at the WLIS Reference station limits the number of species present. The Nucula-Nephtys assemblage present there is comprised predominately of deposit-feeders. Conversely, the heterogeneity of sediment types (sand mixed with mud) in the disposal site allows different lifeforms and feeding types to become established. Species requiring solid surfaces for attachment (e.g., the polychaete Sabellaria, the gastropod Crepidula), tube dwellers or burrowers requiring silty sand or sandy substrate (e.g., the polychaetes Pherusa, Pectinaria, Euclymene, Ampharete; the amphipod Leptocheirus; the bivalves Ensis, Tellina),and deposit feeders (e.g., Euclymene, Ampharete, Mediomastus and Tharyx acutus) all occur at the WLIS-A station. In large part, this sediment type difference accounts for the greater species richness in the survey area relative to the Reference station. The disposal mound station is dominated by surface- dwelling deposit feeders (Mediomastus makes up 52% of all individuals counted). This corresponds to the REMOTS® analysis which indicates that the station closest to the center of mound 15 "A" (5-E), exhibits a Stage I successional status. The benthic results also indicate that some recolonization by deeper- dwelling deposit feeders (Stage III infauna) has occurred in this area. The maldanid, Euclymene zonalis, is the second most abundant polychaete in the samples, and small numbers of Nephtys, and the bivalves Nucula and Yoldia are present. The REMOTS® stations immediately adjacent to station 5-E to the north, east, and west reveal Stage III infauna. It is apparent from these data that benthic recolonization of disposal point "A" is occurring, but at a reduced rate relative to other Long Island Sound disposal sites. This reduced rate of recovery does not appear to be due to any character of the dredged material disposal operations, but rather to the widespread ecosystem stresses (i.e., hypoxia) which are occurring in the western Sound. The benthic community results from the Reference station support this conclusion. In terms of the types of species present, the samples revealed a Nucula-Nephtys deposit- feeding community characteristic of silt-clay bottoms of central Long Island Sound. However, few mature individuals and lower densities of species were found at this station relative to the CLIS Reference station. The REMOTS® analysis detected Stage III seres in only 30% of the Reference images. This area, and western Long Island Sound in general, is apparently experiencing severe ecological stress. 4.5 Body Burden Analysis Lead was the only element that showed significantly (p<0.05) higher concentrations in Nephtys collected from the WLIS mound "A" compared to levels at the Reference station. The mean lead concentrations were 3.7 ppm at WLIS-A and 2.9 ppm dry weight at the Reference station (Table 3-6). These concentrations from both sites are very similar to the levels that Munns et al. (in preparation) reported for the reference station at the Central Long Island Sound Disposal Site (Table 4-3). On dredged material, Munns et al. (in preparation) measured lead concentrations in Nephtys of about 4.7-8.9 ppm. Because the Nephtys analyzed in the present study were purged of gut contents and those analyzed by Munns et al. (in preparation) were not purged, the higher levels for some elements in that study may be due to sediment in the gut of the organisms. The concentrations of zinc and cadmium were Significantly (p<0.05) higher in Nephtys collected from the Reference location when compared to organisms from WLIS-A in the present study. In both cases, however, the levels were similar to or lower than what Munns et al. (in preparation) found at the Central Long Island Sound Reference station (Table 4-3). The cadmium concentrations found in the present study are all lower 16 (0.25-0.48 ppm) than the concentrations reported by Munns et al. (in preparation). Similar results were also observed for chromium and copper. Munns et al. (in preparation) reported that chromium concentrations in Nephtys collected away from dredged material ranged from 1-5 ppm dry weight. This is slightly higher than the range of concentrations (0.42-0.72 ppm) found in the present study (Table 4-3). For copper the range of concentrations reported here are 12-16 ppm compared to about 22-33 ppm at the Central Long Island Sound Reference station (Munns et al. in preparation). The iron concentrations showed a similar trend. The concentrations reported for the present study were between 490 and 570 ppm dry weight whereas those measured by Munns et al. (in preparation) were all between 400 and 1100 ppm. The PCB concentrations reported here (Table 3-8) for Nephtys were below the analytical detection limits for all but two samples. In both cases the measured concentrations were Aroclor 1254 in organisms collected from the Reference station. The levels measured were 420 and 620 ppb dry weight. These levels are slightly higher than those measured by Munns et al. (in preparation) in Nephtys from their Reference station at CLIS (186-375 ppb). It is somewhat surprising to see measurable PCB concentrations in the Reference organisms and not in those collected from the WLIS-A station. This would not be expected because the sediment PCB results showed a level of 90 ppb at the Reference station and 500 ppb at WLIS-A (Table 3-1). In all cases, the measured wet weight concentrations for mercury (Table 3-7) and PCBs (Table 3-8) are well below the FDA Alert Levels (0.2 ppm for mercury, 2 ppm for PCB's). 5.0 CONCLUSIONS The results of the analysis of the bathymetric data collected at the WLIS Disposal Site indicates an accumulation of sediment (estimated from bathymetry surveys to be approximately 35,700 m?) in the vicinity of the disposal buoy. Comparison of the contoured bathymetric charts from the October 1985 and the August 1986 surveys reveals a decrease in depth at the buoy location and on the west flank of mound "C" and the northeast flank of mound "A". Because of the buoy's position between the two mounds, the deposited dredged material will tend to create a Single, wide flat mound. This may, in fact, aid in stabilizing the dredged material. The peaks of dredged material mounds are usually the site of any initial erosion that may occur. AL? The REMOTS® survey showed that recently deposited dredged material was evident in the area of disposal point "C", supporting the results of the bathymetric survey. Much of this newly deposited dredged material consists of coarse-grained sediments (fine to medium sands). This material may extend somewhat beyond the survey area to the east and northeast. However, given that the survey area is approximately 1600 meters west and 900 meters south of the Disposal Site boundaries, it is highly unlikely that this material extends out of the disposal site. Lower contrast dredged material layers were evident in the western portion of the survey area apparently representing material deposited a number of years ago. Apparent relict dredged material is observed in some replicates from the WLIS Reference station. This material is clearly relict (deposited more than just a few years ago) based on its extremely low reflectance and discontinuous layering. Relict dredged material has been observed at this station since the initiation of REMOTS surveys in 1984. The reference station is located close to an historically-used disposal site (Eatons Neck). There is no evidence that recent disposal activities have occurred at this location. Although limited benthic recolonization of the survey area had occurred since the August 1985 survey, the area continued to exhibit a "stressed" biological community. The highly disturbed WLIS Reference community indicated that this stress was not directly related to disposal activities, but reflected a regional ecosystem disturbance factor, i.e., bottom hypoxia. Statistical analyses of the chemical data collected for the sediment at WLIS indicated that the concentrations of lead, nickel, copper, and oil and grease were elevated in the WLIS-A sediment compared to the levels at the Reference station. The concentrations of nickel and copper are, however, only slightly elevated in the dredged material and are within the range of concentrations reported by other investigators for central and western Long Island Sound. The lead concentrations at WLIS-A are, however, elevated compared to what other investigators have found. These same four elements exhibited elevated concentrations in the top 2 cm of the sediment cores when compared to the remaining 2-10 cm for both the disposal mound and Reference station. The reason for only these elements to be elevated is unknown, but more sampling would be required to determine the actual chemical and physical processes occurring in the sediment. In addition to the above elements, the PCB concentration appeared to be high in the WLIS-A sample. For the concentrations of metals in the body tissue of Nephtys, only the concentration of lead was significantly higher in Nephtys collected from WLIS-A compared to levels in organisms collected from the Reference station. This is consistent with 18 significantly elevated levels of lead in the WLIS-A sediment. The concentrations of mercury were well below the FDA Alert Level. In summary, the results of the present survey indicates that the management controls over dredged material disposal at WLIS, initiated by New England Division, Corps of Engineers, have been effective in minimizing the dispersion of dredged material and preventing any significant adverse environmental impacts. Distinct disposal mounds have been formed by disposal operations occurring at taut-moored buoys and appear to be stable with no evidence of erosion or significant transport of material. The "stressed" condition at the disposal site is not attributible to disposal operations but rather to conditions in Western Long Island Sound in general. 6.0 RECOMMENDATIONS The DAMOS monitoring protocol for disposal sites in Long Island Sound depends on comparing disposal site conditions with an appropriate reference, i.e., a nearby area of seafloor which is not affected by the disposal events. The WLIS Reference station was clearly more stressed than the survey area. The reason for this may be low bottom water oxygen. However, it is not clear why the Reference station, located only 2 km east of the survey area, should have been more oxygen stressed. Future monitoring should include some near-bottom oxygen monitoring and an additional reference station should be located to document how widespread are the changes measured at the present one. This may not be possible for this area of the Sound because the study done for EPA Region I has shown that low oxygen water exists at depths of 50 feet or more throughout this area in August. While year-to-year variations may be present in bottom water oxygen, extended periods of low oxygen tensions in the range measured can seriously compromise the benthic habitat throughout the whole region. In short, a relatively undisturbed Reference site may not exist in the vicinity of the disposal site. 7.0 REFERENCES Benninger, kek, Rac. Alden) “o.K. Cochran and K.K. Turekian: 1979. Effects of biological sediment mixing on the 210 Pb chronology and trace metal distribution in a Long Island Sound sediment core. Earth and Planetary Science Letters 43:241-259. Bokuniewicz, H.J., Gebert, J.A., and R.B. Gordon. 1980. Consolidation of a rapidly emplaced deposit of estuarine sediment. Unpublished report, 42p. Ale) Greig), R.A, ReNe Reid sandyD2 “Ra Wenzlotie. 1977. Trace metal concentrations in sediments from Long Island Sound. Marine Pollution Bulletin 8: 183-188. Whetoh=, Welto, Wea, Gols wewuls IWoears shhehaneinl, Dies, Wolo JENS, Wolo Galloway, G.L. Hoffman, R.R. Payne, P.F. Rogerson and R.J. Pruell. (in preparation). Exposure assessment component of the Field Verification Program: Data presentation and synthesis. U.S. Environmental Protection Agency, R.I. Plumb, R.H. 1981. Procedures for Handling and Chemical Analysis of Sediment and Water Samples. Technical Report EPA/CE-81- ale TEWEULeEsO, Wolo weIBs> Sediment Budget Study for Clamshell Dredging and Disposal Activities. US }Armyay (Conpsimot Engineers, New York District. New York, NY. SAIC. 1985. DAMOS Annual Report. SAIC Report #84/7521&C46 , US Army Corps of Engineers, New England Division, Waltham, MA. DAMOS Contribution #46. SAIC. 1986a. Seasonal Monitoring Cruise at the New London Disposal Site, July 1986. SAIC Report #86/7540&C60 , US Army Corps of Engineers, New England Division, Waltham, MA. DAMOS Contribution #60. SAIC. 1986b. Monitoring Surveys at the Western Long Island Sound Disposal Site, August and October 1985. SAIC Report #86/7510&C55 , US Army Corps of Engineers, New England Division, Waltham, MA. DAMOS Contribution #55. SAC Lo Sie REMOTS® reconnaissance mapping of near-bottom dissolved oxygen: Central to western Long Island Sound, August 1986. SAIC Report #87/7502&132. US Environmental Protection Agency, Region I, Boston, MA. 20 °299aTS Tesodstd punos pue{TsT HbuoyT ure3sem suL “*T-z eanbity 4dAY-SIIM® ALIS WSOdSIG aa sip MOOS" Ze EL0 m000"82 E20 MO0S"82 €20 M000°62 E20 MOOS’62 EZ0 A OE Ae fe ee | eel ee Seed Trova FeTeved Bonvq p7 shoes] etre" pe petrcecy Sramie 3-7" ; yore cnt ih rule ue, fy 5 Vides. et ba ‘ / ee), Pat = 4 ‘CMa oF Fie a pie © we 4 a ‘ ; = } ah ve _— ana eT A I — if ae ; as iT Lf : r? 12 ¥¢ G.t e 5a \Aé , e 1 DA .)S awe ao Gar ot es | te th ees hep Lala . Pal Ietice. het res 99 Sea | ey ‘i a es 3 ¢ i. Fat\.. ory Fey Zs Ww ny Rag on ) .e er. 7 = a ONG Re Payoh, ik ap ORS ah ‘ Pewall ; = ie} ae Popa e aCe ey SORE tl Cie | ee oA Pimeetule « Seeks ws win Sx anentat ban } eyr7v. Qos Ps oo ie - ee dll Me » Let eid! = Re he 5 os Ate eee, Rate! Lees. ee | ee, #3 Ge fae gel Aas ‘i of Sealer? and Gat eo Las: Ajai! fant ‘hoger SPAsgE re i Peary a ning mle » srr oy apemmememinsamm on «NO arene ppm em Hy tae .. | Slee Mis dere stucy / ] | i 2 “i 6 434 » WS p rs. at ae fe ia irs Wal RD way: As RRR | Rte mae eon PAG, “pazBOTPUT STE yOu PUL fan ‘un SPUTOd Tesodsta -paze Tesodstp sitm eyq jo Aaaans 9g6T ey} butanp petdnoso suotze3s SLOWHY “¢Z-zZ eanbra MOS Be EZ0 M000 be E20 M0Se be E20 M00S°6e E40 $J9}a4 Ose O0€ OSe O00e OSt OOF OS O —— os ——— cs a 0G) Asepunog ula}SoM Vv Vv Vv Vv 4 Vv Vv Vv Vv l Vv Vv Vv Vv Vv Vv Vv Vv Vv 9 _NOS2'6S OP _|- -|- -|- —|wose' 6s Or Vv Vv Vv Vv Vv Vv Vv Vv Vv G gq Vv Vv Vv Vv Vv Vv Vv Vv Vv Vv 1] Vv Uv 9 Vv Vv Vv Vv Vv Vv Vv € Vv Vv Vv Vv v Vv Vv Vv Vv A NOOS’6S Ob |. 7 ot - : S -|- S 2 9 al I -|- I H y J r| qd > a yy SNOLIVIS SLOWIY SiS WN MOSZ Be EZ M000 6c EZO HOS2 be E20 M00S "Ge E20 WLIS AUGUST 4986 on Western Boundary aa Figure 3-1. Contoured bathymetric chart of WLIS, August 1986. Depth in meters. a 0 50 100 150 200 250 300 350 Meters 073 29.500W 073 29.000H 073 29.000 073 28. 750H j an —— 2 he Cal teat iateal eats © Sa i Saris ram La : ic rae i” ee +a. jt Eo $iynrd -! 6 WS 100 159 200 20 300 300 Met: -_ So eee ee | WLIS 18-30-85 Western Boundary | alo —— cus S as a GE Be Ay Figure 3-2. Contoured bathymetric chart of WLIS, October 1985. Depth in meters. [in Gea SS ee ee ere 873 29. 750 873 29. S80W 15 873 29. 250W 873 29. EBUW —— = SS = ee ——— ee wks 4F *sqzuoutpes Apues Aq pajeuTWOp SseeTe ssOTOUS SAINOVUOD SUL, peqytTqtyxs sonTeA FNOYATM SuUOTReAS TIV MOS/ Be EZO 4000°62 EZO MOGe 62 E20 Vv Vv Vv Vv Vv Vv Vv Vv Vv v Vv Vv NOS2 "6S Ov —+ -{- 4 Vv Vv Vv Vv Vv Vv Vv v Vv On: E sf pues wntpaw Vv Vv Vv Vv Vv Vv NOO0S 6S Ov +. Vv ai Vv v Vv -|- Vv MOSZ°B2 E20 M000°62e E20 M0S¢ 62 E20 -tyd p < jo apow zofeu e *sopow zoflew aezts-uteib Jo uot 4nqtazASTp syL MOOS’ 62 EL0 OSE OOF OSe 002 OSI -€-€ eANnbtTg $J2 ah oo; 0S =O a a 5 SS SSS] Vv Vv Vv Vv Vv Vv “| Vv Vv Vv nk Vv Vv Vv v Vv p < AepTo-3TTs HO0S 6c EZ0 I af (SLINA THd) JQOW YOCWW AZIS-NIVUS GB-SI IM in Baace 2aides ~~ b Geleesiye © td 5 Se aa = : d * ae a. - ate =) = | ves | ; ais i| Se 1 ‘ gn BS tH st 7H — — ‘ = eee rgmet_tety os — — oe — ls — 7 elect Biat na 8 tl ee =<. an aout - - ee ne = Me ‘ie eee ATO Tom ri +o 7 as = Ley wranttoy 280 33s OTF <2Stem. suet sat g-hisi¢c i5. aA invite tas’ .adl =< west <2 ie ToNnS ¥ o44 Aetimed 2iSth Snielomte 22: — f ” & ! = we oy ~ a v a 8) Lt z ) bi em 1] MOGZ Be E20 | pues 1aA0 pnu 1aA0 pues-S/W/S pnu 12aA0 pues 1aao pnw-W/S/W pnu Taao zaAeT pues-W/S xTijeu KeyTo-31Ts ut pues-s NOOS’6S Ob +. MOSZ Be E20 *eoze AdAANS 3yR UT SAaAeCT pues puUe pUeS JO M000 Ge E20 MOSe'be E20 Vv Vv w/s|— W/S Vv Vv W/S Ww/S/W Vv Vv Vv W/S S/W/S W/S/W W/S/W w/S/W eee W/S/W W/S/W H 9 M000 6e E20 MOGe“6e E20 uoT3zNqTIASTp MOOS 62 EZ0 \ | M00S "62 E20 eUuUL °p-€ 2aANbTYy $uajay OSE OO€ OSe 00c OSI 00 —_——_—— | (NWS 40 NOTLNATYLSTC 98-SI IM bet tos 8 Aci, ten ake SPER tases fem preer nae ot wa voieal base. baa Base 30 fcisadiyiaih' se? @-% eae : Figure 3-5. A REMOTS image from station 4-G showing both suface and subsurface sand layers. Also, note the caridean shrimp to the right at the interface. Scale: Actual width of frame = 15.2cm. 4 ed aods Deb nin eS ae ott tA erga ta . P a hepa $4 in nae - di us ‘nreatzt = at Wa sure r Sg hid, _ A. iP MOSZ Be EZO NOS2 6S Or ~{- Tetzsjzew pebperp etqitssog-¢ Tetiazew pebperp yo yo ed-» uot ere -ued uey} TayxoTYR Tetzsqzewu sbhpaiq-+q raket Tetarezew pebpaizg-wa NOOS'6S OP —- MOSZ Be EZO wa wa Wa wa Oo a. oO M000 °6e E20 Vv Vv wa wa Vv wa +d Vv +d +d v v +d J Vv Vv +d +q | wa +g M000 6e E20 wa wd +d td td M0Ge'6e EZ0 wa wd wa wa +d wd MOSe Ge E20 wa é -poze ADAINS STIM OUR UT TeTIezZeU pabperp Fo uoTynqT4z4zSTp SUL MOOS’ be EZO -g-€ BANbTyA Sua jay OSE O0€ OSe O02 OS} OOF O O wa td MOOS 6e E20 SSeS SSS SS SS er T = WIUSLYH 39GINd 40 NOTLNGTYLSTA Gaol Figure 3-7. A REMOTS image from station 5-E showing a low- reflectance dredged material layer overlying a high-reflectance pre-disposal interface (arrow). Also note the patches of reduced (dark) sediment at the interface. Scale: Actual width of frame = 15.2cm. i” C2 woe iad iY Lad ‘batt ie if ian *sooueqinjstp woj}Oq FO SAT}eEOTpUT Seanjzes; Butmoys dew sseooid oTyjueq VW “8-£ eanbtgq MOSL Be ELO M000°6e E20 MO0Se Be EZ0 MOOS Ge E20 CREPE] OSE O0€ OSe O02 OSt 001 _——— Ss es OR 3532) aueyzew-" HO Vv Vv TTeus ow‘su aoerj -JajutT ‘Zeau TO ‘3e sSjueuTpes paonpey-Su = sjseToO pnwW-oW su‘Tteus 31sodep zakeT TTeyus-TTeus NOOS'6S OP i + dvi SS3I0Nd IJTHLNAE MOS/ Be EZ 38-SI IM M000 °6e EZO MOGe “Be EZ MO0S 6c E40 Figure 3-9. A REMOTS image from station 5-F showing reduced (dark) sediment patches at the interface. These features are indicative of recent bottom disturbance. Scale: Actual width of frame = 15.2cm. i sion) } ih , i f y § ’ uy iin ane ; noth aid Devt Figure 3-10. A REMOTS image from station 3-D showing a methane gas pocket at depth in sediment (arrow). Scale: Actual width of frame = 15.2cm. WLIS AUGUST 1986 S os: Zz lu 3 ww O34 N=63 jeg LL WW > 0.2 Saal xq — m 0.1 = { y ' ! Ih i=l = aL T T 1 Om 2OAsOLB ee e2eeInG a2 Ones 4m 226) she) s.6 8 4n0) 474 4°86) 552 BOUNDARY ROUGHNESS (CM) 0.5 WLIS REF AUGUST 1986 > O Zz Ww =) (e) WW o re Ww = = STF =< Math] he ie ra “y ht Bo bs - ae ¥ a i ; aire yet Cl ee ie at" pea a isecttns Bas COR uoT Der -100 ¢q uoT{De1 =si00) ai Sj USuIOD TeuoT3TPPpy Z00°0 GT0°0 Hut ZTPTXO eytp /ATW O°T GT 6°12 T'0 vo'o 83s Buttztptxo) =— “HD /atw OE Ot L°vze (sqy proo O/wddy (wdd) QruryT 9 = odAy oURTY Ton (wu) Way Tuy AQTATATSUeS Uu0T3093.0q /xUePTXO UPTM WUerIND yqbueTeaem UNUITUTW sep 3TTS cure] Arjoulorq9eds uotAdiosqy oTWoRY Suet Aq pezATeuy STe\eW JOJ sqTWT] uoTIOeyeq pue suOCT ITPUCD HuTjZeredo quouwnt SUT T-c 92TAeL oes L ‘D.00€2 :ezTWOIY 98S @Z ‘D.0GL :reUD (oz ‘mMoTZ S25 CE “DEE SACtal Teutiou ‘Ses ¢€) AV 02 OE OT €°€8z Ad = - - - - vS2 6H des L ‘D.00LZ :ezTUOCjY Des @Z ‘.O0IT :reUuD (o€ ‘MOTI SES G “SOE S48ral Teudou ‘oes ¢) AV oz O°T vt 6°LGE ID Ses £ ‘D.00TZ :ezTUljW des 7z '.0GE :1eUuD (oz ‘MOTJ Des ZZ 2) OVE :Aaq Teutou ‘Des ¢€) AV OT O°T v 8°87? 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CS+TVL DC+OL 8°00? °T dot (Acd°p3sF) UPON 08 L°OT ee) 09°0 99°T OOOEE 9¢> 9T Le €> €°v GE ev O°T m10}30¢ ~ °9i10D JO AepuTewer = wo j jog e109 jo wo Z doQq = doy, 2O20N SUOT}D9S 3109 pseuTquod jo stsATeue eThbuts Z puesnoyA ated sqieg I L8 EEE VL? €°OT 3B QS 9T°O 6T°O T2d°O cS °O OVS (0) 6S) ~O) CG°E 86°T 87°C 00062 OOO9E 00062 9¢> 9¢> 9T> L2 ce 90 9v NE cS v 6 €> Es Sie Sac c8 OOT O9oT cS 6G L8 G°T 6°T Lc2°O do. 1109304 dot a SDuSTO JON LL? v°ot 8T°O T9°0O LS O0O0ZE 9¢> (A [ENS S Lg OTT T6 €S0°0O wo 3300 V wudd gdd TeIOL ELE mais eseoid ¥ [TO O°rI zyadd doo GZ°0 uehoARZIN °*R0OL % 15/520 usborpAH °30L % B8G°E uoqaed °20L % OOOLZ udd of 9¢> wdd IN 6S wudd no cv wdd 35D €> wdd po 0°S udd sy O8T udd uz 66 udd qd B°r wdd py dor a 7eoT [dey (stseq qyyubtem Aap e uo suoT}erWQUBDUOD) 9861T 3snbny ‘eqTS Tesodstd SIIM 3e& pezOSeTTOD jUusuTpes Jo stsATeuy TeoTwWeEYD T-€ 9T4eL 0S °*0O COL+OVL 8U+TTT GSO°O+E€C2°O 072°0+8S°0 67 °OFEB°S 00SS+00LUZ2 ETH+SL cT+OV 9°0+0°S GEFELT OT*O+L7°O m03300 S6T+OVCT LE+VET €0°0+¢2°0 S0°0+6S°0 €S*°OFO0L°C OOST+00LS2 cT+cS 8+cOT V+TS 8° C+8°S O9+LTC CEFEES LO°T+LT°T do. (-aoqd°pjs) ues 0S9 SUT 6c°0O 6L°0 DEE OOOOE O00. 6c 68 €G 8 StS OT¢ O9T 6€°O wo 308 9) OOTT O6OoT 9¢eT £eTt 972°0 Tc°O 9S°0 Lv’°O Ot*¢ VIG vv 9¢> OTT EL vS BE 8 S Seay, LS OT? OLT Oc? O6T 69°0 Sv°O dor wo j 08 W-STIM *ponutjuos T-€ eTqeL qd *910D JO AepuTeWeT = wo A QOg °a10D jo woz dol, = doy, :ea j0Nn SUOT}OES 8109 pseuTquos jo stsATeue eTbhuts 2 OSTT v9OT 0c*O v9°0 OT*E 000S2 OOOLZ 9 S6 Lv (SE Bre O9T OT? vv G dor puesnoyA aed sqiaeg I udd gdd Te OL dd 80S O9DT eseetd ¥ [TO L°SS TIT qadd qdoo BESO OBO uehoTRZIN *70L % 6v°O0 95°0 ueboiapAyH +0], & 696 T6s¢ uoqied °30], ¢ OO0O06T 00092 udd of NEE G9 udd ™N v9 OOT wdd no O€ TS wdd 19 €> 8 udd po yoy OnaG udd sv OVT 08d udd uz G¢> OLe udd qd 8S°O 2r°o udd 6H woz70G = 8=6doL WV a3eoT [dey Table 3-2 Physical Characteristics of Sediment from the Biological Samples WLIS Disposal Site, August 1986 Station-Re WLIS-REF-1 WLIS-A ° © Coarse 2 17 ILS) 36 14 nS ° © Med. Sand 2 26 32 30 41 21 ° © Fine Sand 3 11 32 38 30 42 36 z Sslie/ Clay 93 87 91 80 87 25) ILS) 18 Dark olive gray organic clay (OH) with shell fragments Dialraks olive gray organic clay (OH) with shell fragments Dark olive gray organic clay (OH) with shell fragments Dark olive gray organic clay (OH) with sand and shell fragments DeIsIs ~— OQlave gray organic clay (OH) with shell fragments Dark Gray, sisilty,s sand (SM) with shell fragments Dark olive gray silty sand (SM) with shell fragments Dark CGiegayy jgoOOime sy graded sand with gravel (SP) Dark Cees ja@@r2 Ly graded sand (SP) Dark gray silty sand (SM) with shell fragments .. 4 ni _ ’ TG au D kunt i 7 a. shes Lene Last ent ae ad tua ph = ae i Sie: METS. ie ee 2°) $V 216 ts tt ce Fie (AO), ysl OLneoIA . ee ts ee exe ays vhs CUB > OR Li aie) ty S ALE Sa ee eheeapatt eG ae oeeee a f rt LE a Ca 1 aa: CBR Waal aah dali >See x . Tene ere tate C0 tte ). hee8 diiv (Hoy yee olnapying 6S" tie ‘t @ ont fi 0a i _ aynsmpert ¢eze. Vite R7eG: vs iv Fic} Vale 4a nays “ ; } esis Ff aie, - i ! i SR 7 hiniiy Weta NAGD 7 yin nw Li wi ike 4 tik oni vai saa ka eam. w SS Iflate= Atie (MS) pile oo is oi 2 vilznen ¥S2 e is 42%v. Boke &5S seer 1a6) £ > 7 \ hae bot YRS em Lr ie} Boae, ave Siee val ia Vere Geer’ hae CiLate wd * oo ge Oe fig ROR ™ castes fcate ure aca t= er: TS Benthic Community Analysis of Sediment Collected at WLIS SPECIES CNIDARIA Ceriantheopsis americanus RHYNCHOCOELA Cerebratulus lacteus Tubulanus pellucidus Rhychocoela ST PHORONIDA Phoronis mulleri ANNELIDA Oligochaeta spp. Polychaeta Ampharetidae Ampharete arctica Amphitrite ornata Asabellides oculata Capitellidae Mediomastus ambiseta Chaetopteridae Spiochaetopterus oculatus Cirratulidae Tharyx acutus Cossura longocirrata Flabelligeridae Pherusa affinis Glyceridae Glycera americana Hesionidae Podarke obscura Maldanidae Asychis elongata Euclymene torquata Euclymene zonalis Table 3-4 UU August 1986 WLIS-A CENTER REFERENCE Slee Ae ee ees! 2 ile 3 3 2 al 1 2. 5 1 2 2 2 aL 1 : 3 al iE 12 eal 17 4 JL 4 74 92 42 - 5 alt 7 : 1 aL al 2 sto) AOAOQ SOY 102 219 194 al: e * 5 62 US, AS) 0 ° ° . 2 2 2 14 42 43 13 4 11 7 1 2 s o ° 5 3 0 ° 1 ° 6 ° ° . 100 168 87 6 14 SPECIES Nephtyidae Nephtys incisa Nereidae Nereis succinea Paraonidae Paraonis gracilis Pectinariidae Pectinaria gouldii Pilargidae Sigambra tentaculata Phyllodocidae Eulalia bilineata Eteone longa Paranaitis speciosa Polynoidae Harmothoe extenuata Lepidonotus squamatus Sabellaridae Sabellaria vulgaris Sabellidae Potamilla sp. Scalibregmidae Scalibregma inflatum Spionidae Nerinides tridentata Polydora ligni Polydora socialis Spio fillicornis Streblospio bendicti Syllidae Autloytus prolifer Terebellidae Polycirrus eximius Nicolea juv. Table 3-4 Continued. WLIS-A CENTER REFERENCE Al, 2 4 1 4 3 1 17 2 74 113 79 : 5 ll . © : C : 1 : 1 4 6 C : : C - 2 . 2 0 IS} ° 13 s) 1 . 6 C 1 5 0 6 2 . 2 8 2 0 5 . 1 ° 0 7 8 2 99 0 ° : 5 AL all : 2 2 ° ° 5 0 ° ° ° ° 9 : : 2 10 8 2 : 6 0 ° 6 2 1 : 5 6 4 ° O ° . 66 54 . 1 0 ° . ° . 6 ° 1 79 71 by7/ 2 . ° ° 1 ° 2 ° 5 SPECIES MOLLUSCA Arcidae Anadara transversa Lyonsiidae Lyonsia hyalina Mactridae Mulinia lateralis Mytilidae Mytilus spat Nuculanidae Yoldia limatula Nuculidae Nucula annulata Pandoridae Pandora gouldiana Solenidae Ensis directus Tellinidae Tellina agilis Macoma tenta Veneridae Pitar morrhuana Leptonidae Gastropoda Prosobranchia Calyptraeidae Crepidula fornicata Crepidula plana Crepidula spp. Nassariidae Nassarius trivittatus Pyramidellidae Odostomia A Table 3-4 Continued. WLIS-A CENTER 1 2 3 7 28 15 3 4 al 1 3 4 ) 18 Bs) 3 2 2 ° 8 14 9 4 18 62 REFERENCE 1 4 5 11 BIS SOO 3 al 1 Sh 7/ 3 10 35 Table 3-4 Continued. SPECIES ARTHROPODA Crustacea Cephalocarida Hutchinsoniella macracantha Amphipoda Gammaridea Ampeliscidae Ampelisca spp. Corophiidae Corophium acutum Erichthonius brasiliensis Unciola irrorata Photidae Leptocheirus pinguis Stenothoidae Parametopella cypris Caprellidea Luconacea incerta Cumacea Diastylidae Oxyurostylis smithi Isopoda Idoteidae Edotea triloba Decapoda Caridea Crangonidae Crangon septemspinosa Paguridae Pagurus longicarpus Cancridae Cancer irroratus Hemichordata Saccoglossus kowalewskii 20 WLIS-A CENTER 2 4 Al REFERENCE 4 All 0 2 0 0 1 alt 1 4 ° 3 Table 3-4 Continued. SPECIES Total number individuals Polychaetes Mollusca Crustacea Amphipoda 1347 WLIS-A CENTER 2 1790 1608 117 33 23 837 REFERENCE al 4 3 499 766 467 MA Sasa sychal 292 409 Y2) 3 2 36 2 1 28 pdt bine 9 5 i Ere ae A~BEW. chat - ian i. | Labatsistereaa a: CE — 0 : 1" Ree tat a emrwaingtet Alecia, bh cote cone” joie tal | pow peer ' : a) a . : ; won si, eos Tes we Abbe be oa |. Re Table 3-5 Summary of Totals of Species and Individuals Among Major Taxa Collected at Western Long Island Sound Disposal Site, August 1986 CENTER "A" REFERENCE Species/station 5S 47 Total species 68 Species Per Station By Taxa Number % Number %& Polychaeta 28 50n9 19 40.4 Mollusca 14 25.4 12 AB o Crustacea 7 Bo V 10 ZnS Other 6 10.9 6 Ao T/ Individuals/ sample 1493 1790 B79 499 766 487 Mean individuals/ station 1421 584 Individuals Per Station By Taxa Mean Mean Number %& Number & Polychaeta 1264 89.0 296 54.0 Mollusca 96.3 So 7 260 44.5 Crustacea 32 2.2 13.6 2c} Other 29 PR (0) IGS 2.4 Se> OT c 80°0O S0°O TO°O “Asd °p3AS --- O€S vT Lv°O 82°0 Lo O ueoy G0 °0O> 07¢sS rs evo Gz°0. vL°O €-SIIM G0°0O> OVS Sr 9S°0 GZ°0 vL°O @-SIIM G0°0O> OVS VI vv'o ££°O (72,20) T-SIIM 2S OV T 60°0 S0°O Zc0°O "Acq °pas --- O€sS €T £9°0 vv°o S/L°O) ueoHW 9L0°0 OLS cia O20) BPO vL°O € BdUeTeTOY 860°0 O67 Gr vS°O 6£°O €L°0O Z BdUeTSeTSY GO°O> OES SIE £9°0O 9v°O LO TL eouereyoy DH oa nd 26) po id uoT eqs 6/fbn ut uotzerWUeDUOD 986T ysnbny ‘e4TS Tesodstd SIIM 3e pexdeT TOD SA}YdeN JO sonsstL Apog ut (3ybtTemM Arq) sTe_eW sorry, 9-€ 29TqUeL --- € S/O O°) T0'0 EOL --- vOT 8°? 60°0 GO°O i a) TO°O> EOE Tae} 80°0 S0°0O vt°O T0°0> 90T 9°2 EL O S0°0 GiO T0°0> vOT [Lee 80°0 90°0 vT°O --- 9 18 (0) Z0°O LOMO TO°O --- T6 Gee TtaO 80°0O €T°O €T0°O L6_ Cae IE 0) 80°0 FEO) LT0°0 98 16.202 60°0 1O)°O €T°O 800°> 06 Cec ELCO 80°0 Gio DH od nd ELS) po sv 6/6bn ut uotzerQUsDUO0D 986T ysnbny ‘e4TS Tesodstq SIIM 3e peqyoeTTOD SA}YdeN Jo senssty Apog ut (QUuHhTeM 4oM) STeQeW soLIL Z-€ 9TqeL ANM “Aed *P3S ueohl €-SIIM c-SIIM T-SIIM "Aed °pys uray sdUueTeToY sdUueTeyoY adueTVJoy WoT #e4S Table 3-8 PCB Concentrations in Nephtys Collected at WLIS Disposal Site August 1986 Reference WLIS Dry Weight (ppb) 1 420 <300 <570 <350 620 <400 Wet Weight (ppb) Ya. <58 <100 <69 105 <78 1 concentrations and detection limits as Aroclor 1254. See Methods section for discussion of relationship to other PCB mixtures. No other PCB mixtures were detected. Table 4-1 Comparison of REMOTS Data from the August 1986 and October 1985 Surveys at WLIS Mean RPD Mean OSI (cm) WLIS Stations 1.62 3.18 October 1985 (n=22) WLIS Stations 2.16 ns Berge August 1986 (n=56) WLIS Reference 0.59 * =O 70m s August 1986 (n=22) Note: ns indicates that results of the comparison to the October data was not significantly different (Kruskal-Wallis, p>0.05). * indicates a significant difference (p<0.05). Hg Pb an As Cd (Gis Cu Ni Table 4-2 Comparison of Chemical Analysis of Sediment Collected ppm ppm ppm ppm ppm ppm ppm ppm Note: in Long Island Sound (Concentrations on a dry weight basis) Greigt Benninger2 WLIS-aA? WLIS-REF2> 0.5-0.6 ON 39=214 0.05-1.9 58-77 30-52 <25-270 43-99 195-201 106-190 140-280 82-180 NbD4 3.8-9.0 2.8-5.0 ND <3-8 <3-9 159-164 30-54 27-52 122-154 44-96 64-110 16-59 220226 <26-65 <26 from Greig et al. (1977); results from two stations in the valcinity of WEES) top) 4 icmeot icones ouirmon es oisalr from Benninger et al. (1979); results from top 10 cm of one core collected in the vicinity of the CLIS disposal site. includes results from 0-2 and 2-10 cm core sections. ND = not detected. Table 4-3 Comparison of Chemical Analysis of Nephtys Collected in Long Island Sound (Concentrations on a dry weight basis) Munns et al.! On DM Reference WLIS-A WLIS-REF 4.7-8.9 2.6-4.4 3.5-3.8 Bo PCS 5 Al 150-220 25 = A775) 130-140 150-160 0.5-2.7 0.9-1.8 0.25-0.33 0.39-0.48 No OS55'7/ 1.0-2.4 0.42-0.56 0.54-0.72 36-64 22-33 13-16 12-13 500-1100 430-790 520-540 490-570 610-838 186-375 ND3 420-620 from Munns et al. (in preparation); results from Field Veriiication) “Program (VP) Ysite! in’ the (Central Long Island Sound Disposal Site. Concentrations as Aroclor 1254. ND = not detected. ¥ U. S. 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