Black Rock Harbor Research Articles

Inhibitory relationships of resident bacteria isolated from the mantle fluids of Crassostrea virginica.

Thirteen aerobic, halotolerant marine bacterial strains were isolated from the mantle fluids and associated mucus of the eastern oyster Crassostrea virginica harvested from the highly impacted Black Rock Harbor in western Long Island Sound. All isolated strains were Gram negative and had previously been identified using 16S RNA gene sequence analysis. These 13 strains were examined for their ability to inhibit the growth of each other employing a diffusion agar method used by antibiotic assays. All challenger strains were able to inhibit at least one of the indicator isolates. Enhanced antimicrobial activity was observed from cultures of Pseudoalteromonas sp. (L), Shewanella sp. (H), Thalassospira sp. (JA), and Alteromonas sp. (JB) when used to challenge the indicator isolates. The indicator isolate most sensitive to antimicrobial activity was another Pseudoalteromonas species (KC) whose growth was inhibited by 10 of the challenger strains, whereas Pseudoalteromonas (L) was resistant to all growth challenges. Growth autoinhibition was observed with isolates Tenacibaculum ascidiaceicola (KC), Vibrio (B), and Shewanella (H) during a 24 h incubation. No antimicrobial growth inhibition was detected when 24 and 48 h cell-free extracts of these isolates were used to challenge indicator isolate growth.

Antimicrobial Activity in the Pallial Cavity Fluids of the Ribbed Mussel Geukensia Demissa from a Highly Impacted Harbor in Western Long Island Sound

Fluid and its associated mucus from the pallial (mantle) cavity of the ribbed mussel Geukensia demissa (Dwillyn) from Black Rock Harbor, Bridgeport, CT, inhibited the growth of both Gram-positive (Staphylococcus aureus) and Gramnegative (Escherichia coli) bacteria in antimicrobial assays. A significant reduction in size after 24 h was noted in E. coli grown in the presence of ribbed mussel fluid. Mussel-soluble lysozyme levels in the pallial cavity fluid averaged 0.019 + 0.018 relative fluorescence units/mg protein, and no seasonal pattern of lysozyme activity was found (P = 0.522). During the course of the study, copper concentrations ranged from 0.09 to 0.37 ppm and zinc concentrations from 0.17 to 0.66 ppm in the pallial cavity fluid. These values were only slightly higher than the concentrations of these metals found in seawater samples taken at the site, indicating only very low levels of sequestration of heavy metals by G. demissa in the pallial fluid cavity. A comparable study of oysters (Crassostrea virginica) from the same site found lysozyme levels 10 times higher and zinc concentrations two orders of magnitude greater than in that in mussels reported here (Brousseau et al. 2014). These results suggest substantial interspecies variation in profiles of defensive agents involved in antimicrobial activities of marine bivalves and highlight the need for additional studies to characterize these differences.

Antimicrobial Activity in the Pallial Cavity Fluids of the OysterCrassostrea virginica(Gmelin) from a Highly Impacted Harbor in Western Long Island Sound

ABSTRACT Fluid and its associatedmucus from the pallial (mantle) cavity of eastern oysters Crassostrea virginica (Gmelin) from Black RockHarbor, Bridgeport, Connecticut, inhibited growth of both Gram-positive (Bacillus subtilis, Staphylococcus aureus) and Gram-negative (Escherichia coli, Serratia marcescens, and Vibrio parahaemolyticus) bacteria in antimicrobial assays. In the presence of oyster fluid, E. coli resulted in significant reduction in growth after 26 h. Soluble lysozyme activity in pallial cavity fluid of oysters collected in the fall was 3 times greater than that measured in combined winter—spring—summer samples (P = 0.0008). During the course of the study, copper concentrations in pallial cavity fluid ranged from 0.60–2.49 ppm and zinc concentrations ranged from 9.7–61.0 ppm. Copper concentrations remained relatively constant throughout the study; the highest zinc concentrations were recorded in the fall. Fall antimicrobial assays showed heightened antimicrobial activity compared with the sp...

Impact of Predation by the Invasive CrabHemigrapsus sanguineuson Survival of Juvenile Blue Mussels in Western Long Island Sound

Hemigrapsus sanguineus (Asian Shore Crab) has shown a remarkable ability to colonize rocky intertidal communities along the east coast of the United States since its introduction in the late 1980s and is an important predator of juvenile Mytilus edulis (Blue Mussel) in invaded habitats. In this study, we used two field-caging experiments and the Kaplan-Meier model to assess the impact of predation by Asian Shore Crab on the survival of juvenile Blue Mussels in an intertidal habitat of western Long Island Sound along the Connecticut coastline. Five treatment levels (high-density enclosure, low-density enclosure, exclosure, partial cage, and open plot) were used in the 2007 experiment. The high-density enclosure treatment was omitted in the 2010 experiment since there was no statistically significant difference in the proportion of mussels surviving between low- and high-density crab treatments in 2007. In 2007, we measured a statistically significant difference in mussel mortality between exclosure and crab-enclosure cages, with crabs lowering the median survival time for mussels from 15.4 to 7.6 days. In 2010, we again measured a statistically significant difference in mussel mortality between exclosure and crab-enclosure cages, suggesting a crab effect on mussel survival. In the 2010 experiment, approximately 25% of the mussel mortality was attributable to crab predation, which reduced median survival time for mussels from 12.8 to 5.6 days. The median survival time for mussels exposed to the full complement of factors affecting survival (open plots and partial cages) was only 2–3 days. Our study shows that predation by Asian crabs may account for up to 25% of the Blue Mussel mortality in the intertidal zone at Black Rock Harbor. Further studies focusing on the importance of other biotic and abiotic factors are needed to understand the apparent declines in Blue Mussel populations and the interannual variability in recruitment success in this area.

The influence of worm age, duration of exposure and endpoint selection on bioassay sensitivity for Neanthes arenaceodentata (Annelida: Polychaeta)

AbstractThe influence of worm age, duration of exposure, and endpoint selection on bioassay sensitivity were evaluated for Neanthes arenaceodentata. Worms were exposed to contaminated sediment collected from Black Rock Harbor (BRH) near Bridgeport, Connecticut, USA. This sediment was diluted with clean control sediment to result in five experimental treatments: 0, 25, 50, 75, and 100% BRH. Three exposure scenarios were employed: (1) a 4‐week exposure beginning with newly emerged juveniles (EJ–4w), (2) a 7‐week exposure beginning with newly emerged juveniles (EJ–7w), and (3) a 4‐week exposure beginning with 3‐week‐old juveniles (3WO–4w). Six measures of worm size were recorded at the conclusion of each exposure to evaluate differences among measurement endpoints. Survival was significantly reduced at the 25% BRH level for the EJ–7w scenario and at the 100% BRH level for the EJ–4w and 3WO–4w scenarios. Growth was significantly reduced at the 25% BRH level in each exposure scenario. Estimates based on the calculated minimum detectable difference indicated that considerably lower concentrations of BRH (6–10%) should be distinguishable by measuring effects on Neanthes growth. Worm size measured in terms of projected area, dry weight, and ash‐free dry weight provided the most sensitive measures of effects. Increasing the length of exposure from 4 to 7 weeks and initiating exposures with emergent juveniles rather than 3‐week‐old worms increased the sensitivity of the bioassay. The results of this study demonstrate that N. arenaceodentata is sensitive to the presence of sediment‐associated contaminants and that test animal age, duration of exposure, and choice of endpoint can have a large effect on the magnitude of the toxic response observed.

The influence of food ration on sediment toxicity in Neanthes arenaceodentata (Annelida: Polychaeta)

AbstractA 3 × 2 factorial experiment was conducted to evaluate the influence of food ration on observed toxicity in Neanthes arenaceodentata. Worms were fed one of three food rations: 0.25×, 1.0×, and 6.0×. The 1.0× ration was composed of 4 mg TetraMarin/worm/week and 2 mg alfalfa/worm/week. Worms in each food ration were exposed to one of two sediments: a clean control sediment collected from Sequim Bay, Washington, USA (SC) or a contaminated sediment collected from Black Rock Harbor near Bridgeport, Connecticut, USA (BRH) that was diluted with SC such that the final concentration of contaminated sediment was 12%. Survival and growth were monitored every 2 weeks for 8 weeks. Sediment treatment and food ration had strong effects on survival and growth patterns in N. arenaceodentata. Most of the mortality within any given treatment combination occurred during the first 2 weeks of the experiment. This decline in survival was greatest for worms exposed to BRH. Survival was significantly lower for worms in BRH compared to SC at the 0.25× and 1.0× ration levels. Survival was not reduced for worms in BRH compared to SC at the 6.0× ration level. Worm size during the course of the experiment was positively related to ration level. Significantly reduced size in BRH worms was observed at each monitoring period within the 0.25× and 1.0× rations, but only at weeks 6 and 8 for the 6.0× ration level. The percent difference in size between worms exposed to BRH and SC, when those worms were fed the 0.25× or 1.0× rations, ranged between 55 and 66%. The percent difference in size observed between BRH and SC worms fed the 6.0× ration was much smaller (9–17%). The results of this study demonstrate that food ration has a strong influence on observed toxicity in N. arenaceodentata. The importance of food ration effects on toxicity must be considered while designing chronic sublethal bioassays. To ensure the relevance of bioassay results, the food ration used during a chronic bioassay should produce a pattern of growth in control animals that is similar to patterns of growth observed in nature.

Interlaboratory comparison of a 10‐day sediment toxicity test method using Ampelisca Abdita, Eohaustorius Estuarius and Leptocheirus Plumulosus

Estuarine and marine amphipods have been chosen by the U.S. Environmental Protection Agency (EPA) for use in standardized 10-d sediment toxicity tests. An interlaboratory comparison (round robin) was conducted to evaluate the precision of these methods. This comparison included three species, Ampelisca abdita, Eohaustorius estuarius, and Leptocheirus plumulosus. Each species was exposed for 10 d under static, nonrenewal conditions to four sediment treatments using standardized, species-specific test protocols by at least six independent facilities. Sediment treatments were selected for each species to include one negative control sediment and three contaminated sediments. Highly contaminated sediment from Black Rock Harbor (BRH), Connecticut, was diluted with species-specific, noncontaminated control sediment, creating test sediments that ranged in relative contamination from low to high. Laboratories showed strong, logical agreement in rank survival for all species, with control sediment consistently exhibiting the highest survival, and sediment with the greatest proportion of BRH consistently exhibiting the lowest survival. Although instances of considerable interlaboratory variability occurred, laboratories showed acceptable survival and variability in control sediments, significant agreement in ranking sediment toxicity, and agreement in the categorization of sediments as toxic or nontoxic for all three species.

Liver Lesions in Winter Flounder (Pseudopleuronectes americanus) from Jamaica Bay, New York: Indications of Environmental Degradation

Liver sections of winter flounder (Pseudopleuronectes americanus) collected from Jamaica Bay and Shinnecock Bay, New York, in 1989, were examined microscopically to determine the pervasiveness of liver lesions observed previously in Jamaica Bay winter flounder. Neoplastic lesions were not detected in fish from Jamaica Bay or the Shinnecock Bay reference site. Twenty-two percent of Jamaica Bay winter flounder examined (n=103) had unusual vacuolization of hepatocytes and biliary pre-ductal and ductal cells (referred to hereafter as the vacuolated cell lesion). The lesion, identical to that found in 25% of Jamaica Bay winter flounder examined in 1988, has previously been identified in fishes taken from highly polluted regions of the Atlantic coast (e.g., Boston Harbor, Massachusetts, and Black Rock Harbor, Connecticut). Prevalence of the vacuolated cell lesion in winter flounder from Jamaica Bay was significantly greater (p<0.0001) than in 102 specimens collected from Shinnecock Bay. Current scientific literature indicates vacuolated hepatocytes and cholangiocytes are chronically injured and that the extent of their deformity is consistent with the action of a hepatotoxicant. The high prevalence of vacuolated hepatocytes in Jamaica Bay winter flounder and absence of the lesion in flounder from reference sites strongly supports the hypothesis that this impairment is a manifestation of a toxic condition in at least some portions of Jamaica Bay.

Effects of Black Rock Harbor sediments on indices of biotransformation, oxidative stress, and DNA integrity in channel catfish

Selected biochemical responses were measured in channel catfish ( Ictalurus punctatus) exposed in the laboratory to sediments obtained from either of two sites in Long Island Sound, CT. These sites were Black Rock Harbor, which is highly contaminated with various aromatic hydrocarbons, and a relatively uncontaminated reference site. Livers and bile were removed from fish on days 2, 7, 14, and 28 following the initiation of sediment exposures and examined for responses associated with (1) xenobiotic biotransformation, (2) oxidative stress, and (3) DNA integrity. Relative to reference sediment exposures in fish, exposures to Black Rock Harbor sediments elicited on at least two of the four sampling points significant ( P < 0.05) increases in: (1) phase I biotransformation enzyme activities (EROD and ECOD) and concentrations of bile metabolites of polycyclic aromatic hydrocarbons (PAHs); (2) antioxidant enzyme activities (SOD and catalase), concentrations of reduced and oxidized glutathione, and malondialdehyde (an index of lipid peroxidation); and (3) the fraction of DNA as single-stranded DNA following alkaline unwinding (an index of strand breaks). The results of this study support hypotheses concerning mechanistic relationships in benthic fish among the metabolism of sediment-associated aromatic hydrocarbons, the generation of free radical intermediates, and mutagenesis. Furthermore, these results support the utility of biochemical responses as tools for assessing contaminant exposures and sublethal effects in aquatic animals.

Bioassay-directed fractionation of organic contaminants in an estuarine sediment using the new mutagenic bioassay, mutatox™

Bioassay-directed fractionation of organic compounds was performed on an organic solvent extract of a contaminated estuarine sediment from Black Rock Harbor, Connecticut, using the new mutagenic bioassay, Mutatox™. Chemical fractionation methods of the sediment extract included silica-gel-column chromatography (SGCC), followed by C18 reverse phase HPLC. Compound identification was performed using GC-MS. Mutatox analyses indicated that four of the eight HPLC fractions contained mutagenic or epigenetic compounds. GC-MS analyses detected known mutagenic polycyclic aromatic hydrocarbons (PAHs) in two of the four mutagenic fractions. GC-MS analyses of the other two mutagenic fractions (one operational blank and one sediment fraction) showed no known mutagenic compounds. SGCC and HPLC, combined with the Mutatox bioassay, were useful in reducing both the number and the complexity of fractions analyzed by GC-MS. The Mutatox bioassay is a promising tool for bioassay-directed fractionation.

BIOASSAY-DIRECTED FRACTIONATION OF ORGANIC CONTAMINANTS IN AN ESTUARINE SEDIMENT USING THE NEW MUTAGENIC BIOASSAY, MUTATOX™

Bioassay-directed fractionation of organic compounds was performed on an organic solvent extract of a contaminated estuarine sediment from Black Rock Harbor, Connecticut, using the new mutagenic bioassay, Mutatox™. Chemical fractionation methods of the sediment extract included silica-gel-column chromatography (SGCC), followed by C18 reverse phase HPLC. Compound identification was performed using GC-MS. Mutatox analyses indicated that four of the eight HPLC fractions contained mutagenic or epigenetic compounds. GC-MS analyses detected known mutagenic polycyclic aromatic hydrocarbons (PAHs) in two of the four mutagenic fractions. GC-MS analyses of the other two mutagenic fractions (one operational blank and one sediment fraction) showed no known mutagenic compounds. SGCC and HPLC, combined with the Mutatox bioassay, were useful in reducing both the number and the complexity of fractions analyzed by GC-MS. The Mutatox bioassay is a promising tool for bioassay-directed fractionation.

Vitellogenin in Winter Flounder (Pleuronectes americanus) from Long Island Sound and Boston Harbor

Vitellogenin is an egg-yolk precursor protein in teleosts which is crucial to the survival of larvae. Manufactured in the liver, where pollutants are known to accumulate, and transported to the ovary by the blood, its synthesis by the liver or uptake by the gonad can be compromised by accumulation of xenobiotics. In three studies, winter flounder (Pleuronectes americanus) blood samples were taken to determine normal levels of vitellogenin during the reproductive cycle, and to learn how its production might be affected in degraded environments. Specifically, these studies followed the seasonal cycle of vitellogenin production in winter flounder through monthly sampling at relatively clean (Shoreham, New York) and degraded areas (Black Rock and New Haven harbors, Connecticut) in Long Island Sound; examined the relationship between parental vitellogenin levels and survival of offspring by sampling fish that had been spawned at the Milford Laboratory for a reproductive success study; and determined the effect of gross liver lesions on vitellogenin production by sampling flounder from Boston Harbor, Massachusetts, which have been reported to have a high prevalence of liver tumors. Blood vitellogenin levels were determined by measuring alkali-labile phosphate (ALP). Large fish (>30 cm) from the two degraded sites had elevated serum ALP levels relative to those from the clean area. Lowered total ovarian lipid levels in large fish from Black Rock Harbor suggested impaired vitellogenin uptake. There were no significant differences in serum ALP among the small (≤30 cm) fish from the three sampling sites. Boston Harbor flounder with gross liver lesions had lower ALP values than fish without such lesions. There were no significant differences in ALP values among the spawned fish.

Chemometric comparisons of polychlorinated dibenzo-p-dioxin and dibenzofuran residues in surficial sediments from Newark Bay, New Jersey and other industrialized waterways

The distributions of 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) measured in surficial sediments from the lower Passaic River and Newark Bay, New Jersey were compared to those observed in sediments from other waterways located within industrial or heavily populated areas using chemometric techniques. Comparisons were conducted using published data to determine whether the distributions of 2,3,7,8-substituted isomers in surficial sediments from industrialized waterways have similar or different fingerprint patterns. Chemometric evaluations consisted of principal components analysis and the complete linkage: farthest neighbor cluster method. The concentrations of individual isomers were normalized to the combined sum of the 2,3,7,8-substituted PCDD and PCDF isomer concentrations in order to evaluate relative distribution patterns. Several of the isomeric fingerprint patterns found in sediments from the lower Passaic River and Newark Bay were similar to those found in sediments from New Bedford Harbor, MA, USA, Black Rock Harbor, CT, USA, Providence River, RI, USA, Eagle Harbor, WA, USA, the Inner Stockholm archipelago, Sweden, Hamburg Harbor, Germany, and St. Laurensharbor, The Netherlands. Pattern differences were observed in sediments from Frierfjorden, Norway, Niagara River, NY, USA, and Chemieharbor, The Netherlands. The variations among the 2,3,7,8-substituted isomer patterns observed in different sediments were largely explained by the distributions of the higher chlorinated isomers. Other differences may be attributed to environmental conditions unique to each waterway such as tidal flux, shipping traffic, urbanization, sedimentation rates, and the presence of different industrial sources. Similarities in PCDD and PCDF patterns among the waterways were related to the presence of similar municipal and industrial sources, including effluents from pentachlorophenol and polychlorinated biphenyl manufacturing facilities, pulp and paper mills, automobile and shipping traffic, and municipal solid waste and industrial incinerators. The distributions of PCDDs and PCDFs in surficial sediments from some areas of the Newark Bay estuary were representative of those found in many industrialized regions. It wsa evident from this analysis that the application of chemometric analysis can be useful in characterizing the distribution of complex multi-constituent chemical residues and identifying sources of these compounds in freshwater, estuarine, and marine sediments.

An examination of dechlorination processes and pathways in New Bedford Harbor sediments

Estuarine sediments from upper New Bedford Harbor, Massachusetts, which were heavily contaminated with polychlorinated biphenyls (PCBs), showed considerable compositional alterations of PCB residues relative to mixtures of Aroclor 1242 and 1254 standards, and PCB distributions present in sediments from lower New Bedford Harbor and Black Rock Harbor, Connecticut. The compositional alterations, which presumably resulted from reductive dechlorinations by bacteria, became more extensive with increasing PCB concentration and decreasing distance from the suspected PCB source, an electrical capacitor manufacturing plant. Three pathways which removed chlorine substituents from specific locations on PCB molecules were responsible for most of the observed dechlorinations. Considerable differences were found in the extent of dechlorination within sediment cores and between sampling sites in upper New Harbor. The most extensively altered PCB distribution was found in the 15–17·5 cm deep section of a core from nearest to the plant's outfall. In most cores, less altered PCB residues were found in the 0–2·5 and 5–7·5 cm core sections than in the 15–17·5 cm section. Large variations in estimates of dechlorination rates were found, depending on the sample and the congener. The dechlorination processes found may decrease the potential toxicity and bioaccumulation potential of the PCB residues in these sediments.

Chemical induction of Tumors in oysters by a mixture of aromatic and chlorinated hydrocarbons, amines and metals

Tumors were induced in eastern oysters ( Crassostrea virginica) by a mixture of aromatic hydrocarbons, an aromatic amine, polychlorinated biphenyls, chlorinated hydrocarbons, a nitrosoamine and heavy metals. Kidney and enteric tumors developed in oysters following exposure to a mixture containing 3,4-benzopyrene, 1,2-benzanthracene, 2-aminofluorene. N-nitrosodiethylamine, technical chlordane, Aroclors 1242 and 1254, p.p'DDE, cadmium (CdCl 2), chromium (K 2CrO 4) and lead (Pb(NO 3) 2). The chemical concentrations added to a reference sediment from Long Island Sound were 1 x and 10 x the measured level in sediment from Black Rock Harbor (BRH), Bridgeport. Connecticut (normalized for total organic carbon and acid volatile sulfide content for organic and inorganic compounds, respectively). 2-Aminoflourene and N-nitrosodiethylamine, not measured in BRH sediment, were both added at 0·6 and 6·0 μ/g dry sediment. A 3% prevalence of low-grade renal and gastrointestinal tumors developed after 30 days in oysters fed water-column suspended sediment particulate spiked with the mixture of chemicals. Disease progression was most advanced in enteric adenomas. Both types are comparable to those produced after 30 days in the same organs by chemically contaminated Black Rock Harbor sediment. The action of chemical pollutants reported here represents initial findings in a series of studies designed to test sediment contaminants as causal factors for tumors in oysters.

Genotoxic effects of complex marine sediment extracts on V79 chinese hamster lung fibroblasts

A mammalian in vitro system was used to evaluate the genotoxic potential of two complex environmental samples. Sister chromatid exchanges (SCEs) were measured in Chinese hamster V79 lung fibroblast cells, following exposure to whole extracts of sediments collected from a highly contaminated harbor — Black Rock Harbor, Connecticut (BRH) — and from a reference site — central Long Island Sound (CLIS). Characterization of BRH sediment by analysis of prepared chemical extracts revealed high concentrations of polyaromatic hydrocarbons, anthraquinones, carbazoles, and several inorganic substances that are genotoxic and capable of inducing SCEs. The CLIS sediment, although cleaner than BRH sediment, does contain low levels of similar contaminants. For instance, BRH sediment contains 3.16 μg/g of the polynuclear aromatic hydrocarbon benzo[a]pyrene (BP), whereas CLIS sediment contains only 0.807 μg/g BP. Sediments were extracted with organic solvents and redissolved in dimethyl sulfoxide (DMSO) for culture exposure. Following exposure, extract-treated cells were evaluated for increased frequencies of SCEs. All assays were performed with and without exogenous S9 activation. Positive responses were observed only in the presence of exogenous S9 metabolism. Results indicated a concentration-dependent increase in SCEs in cells exposed to whole BRH sediment extracts and a smaller but significant increase in SCEs in cells exposed to whole CLIS sediment extracts. Four times as much CLIS material (0.13 g extracted sediment [dry wt.]/ml of exposure media) was needed to induce a significant doubling in SCEs, compared to BRH material, in which only 0.03 g extracted sediment (dry wt.)/ml of exposure media was needed. These findings imply that this short-term in vitro bioassay can be used to evaluate the genotoxic potential of complex environmental samples such as contaminated marine sediments.

Carcinogenicity of Black Rock Harbor Sediment to the Eastern Oyster and Trophic Transfer of Black Rock Harbor Carcinogens from the Blue Mussel to the Winter Flounder

The eastern oyster (Crassostrea virginica) developed neoplastic disorders when experimentally exposed both in the laboratory and field to chemically contaminated sediment from Black Rock Harbor (BRH), Bridgeport, Connecticut. Neoplasia was observed in oysters after 30 and 60 days of continuous exposure in a laboratory flow-through system to a 20 mg/L suspension of BRH sediment plus postexposure periods of 0, 30, or 60 days. Composite tumor incidence was 13.6% (49 neoplasms in 40, n = 295) for both exposures. Tumor occurrence was highest in the renal excretory epithelium, followed in order by gill, gonad, gastrointestinal, heart, and embryonic neural tissue. Regression of experimental neoplasia was not observed when the stimulus was discontinued. In field experiments, gill neoplasms developed in oysters deployed in cages for 30 days at BRH and 36 days at a BRH dredge material disposal area in Central Long Island Sound, and kidney and gastrointestinal neoplasms developed in caged oysters deployed 40 days in Quincy Bay, Boston Harbor. Oysters exposed to BRH sediment in the laboratory and in the field accumulated high concentrations of polychlorinated biphenyls (PCBs), polyaromatic hydrocarbons (PAHs), and chlorinated pesticides. Chemical analyses demonstrated high concentrations of PCBs, PAHs, chlorinated pesticides, and heavy metals in BRH sediment. Known genotoxic carcinogens, co-carcinogens, and tumor promoters were present as contaminants. The uptake of parent PAH and PCBs from BRH sediment observed in oysters also occurs in blue mussels (Mytilus edulis). Winter flounder fed BRH-contaminated blue mussels contained xenobiotic chemicals analyzed in mussels. The flounder developed renal and pancreatic neoplasms and hepatotoxic neoplastic precursor lesions, demonstrating trophic transfer of sediment-bound carcinogens up the food chain.

Carcinogenicity of Black Rock Harbor sediment to the eastern oyster and trophic transfer of Black Rock Harbor carcinogens from the blue mussel to the winter flounder.

The eastern oyster (Crassostrea virginica) developed neoplastic disorders when experimentally exposed both in the laboratory and field to chemically contaminated sediment from Black Rock Harbor (BRH), Bridgeport, Connecticut. Neoplasia was observed in oysters after 30 and 60 days of continuous exposure in a laboratory flow-through system to a 20 mg/L suspension of BRH sediment plus postexposure periods of 0, 30, or 60 days. Composite tumor incidence was 13.6% (49 neoplasms in 40, n = 295) for both exposures. Tumor occurrence was highest in the renal excretory epithelium, followed in order by gill, gonad, gastrointestinal, heart, and embryonic neural tissue. Regression of experimental neoplasia was not observed when the stimulus was discontinued. In field experiments, gill neoplasms developed in oysters deployed in cages for 30 days at BRH and 36 days at a BRH dredge material disposal area in Central Long Island Sound, and kidney and gastrointestinal neoplasms developed in caged oysters deployed 40 days in Quincy Bay, Boston Harbor. Oysters exposed to BRH sediment in the laboratory and in the field accumulated high concentrations of polychlorinated biphenyls (PCBs), polyaromatic hydrocarbons (PAHs), and chlorinated pesticides. Chemical analyses demonstrated high concentrations of PCBs, PAHs, chlorinated pesticides, and heavy metals in BRH sediment. Known genotoxic carcinogens, co-carcinogens, and tumor promoters were present as contaminants. The uptake of parent PAH and PCBs from BRH sediment observed in oysters also occurs in blue mussels (Mytilus edulis). Winter flounder fed BRH-contaminated blue mussels contained xenobiotic chemicals analyzed in mussels. The flounder developed renal and pancreatic neoplasms and hepatotoxic neoplastic precursor lesions, demonstrating trophic transfer of sediment-bound carcinogens up the food chain.

A comparative study of the differential blood cell counts of winter flounder ( Pseudopleuronectes americanus) collected in New England

Major alterations in the distribution of peripheral blood cells were observed among winter flounder ( Pseudopleuronectes americanus) from Martha's Vineyard (MV), East Cape Cod Bay (ECCB), Fox Island (FI) (Narragansett Bay), Central Long Island Sound (CLIS), Gaspee Point (GP) (Narragansett Bay), Black Rock Harbor (BRH) (Bridgeport, CT), New Bedford Harbor (NBH) and Quincy Bay (QB) (Boston Harbor). Collection locations ranged from relatively uncontaminated offshore (MV) and nearshore (ECCB) sites to the more contaminated estuarine (FI, CLIS) and urban embayments (GP, BRH, NBH, QB). Differential diagnosis demonstrated a shift in lymphocyte counts from 28% (MV) to 54% (QB) that increased with the incidence of liver lesions in relation to known and suspected levels of sediment chemical contamination. A significant change in the ratio of circulating immature to mature erythrocytes was observed in flounder collected from Boston Harbor. Immature erythrocytes comprised 18% of the total erythrocyte population of fish from QB in comparison to 6% observed in flounder from ECCB.

Comparative histopathological effects of chemically contaminated sediment on marine organisms

Comparative pathological effects in three species of fish and six species of invertebrates were investigated using a chemically contaminated sediment from Black Rock Harbor (BRH), Connecticut, USA. Substances contained in BRH sediment are known to be genotoxic, carcinogenic, co-carcinogenic and tumor-promoting. Proliferative lesions were observed in winter flounder ( Pseudopleuronectes americanus) external, oral and esophageal epithelial surfaces, renal vascular and nephroblastic elements, and the pancreatic islets. Islet lesions included cystic adenomas and a diffuse islet proliferative condition, nesidioblastosis. In addition, pathology was enhanced when winter flounder were fed mussels ( Mytilus edulis) previously exposed to BRH sediment. Neoplastic lesions developed in kidney tubule epithelia, gills, some regions of the gastrointestinal tract, neural elements and heart of oysters ( Crassostrea virginica) exposed to BRH sediment for 30 days in the laboratory. In addition, renal carcinomas in three oysters had metastasized to the viseral ganglion. Lesions were also found in oysters exposed in situ in BRH and Long Island Sound for 30 or 36 days. Digestive diverticula, gills and kidneys appeared to be the prime organs affected in mussels, soft-shelled clams ( Mya arenaria) and oysters exposed to BRH sediment. Mucous cell activity increased greatly in corals ( Astrangia densa) while no microscopic lesions were detectable in lobster ( Homarus americanus) exposed in the laboratory. Myxomas were also found in the hearts of < 5% of the mussels exposed in the laboratory.