Grantee Research Project Results
Final Report: Transport of Polychlorinated Biphenyls from Adult Oyster Crassostrea virginica to Embryos and Larvae and Potential for Reproductive and Developmental Impairments
EPA Grant Number: R825349Title: Transport of Polychlorinated Biphenyls from Adult Oyster Crassostrea virginica to Embryos and Larvae and Potential for Reproductive and Developmental Impairments
Investigators: Chu, Fu-Lin E. , Hale, Robert C.
Institution: College of William and Mary-VA , Virginia Institute of Marine Science
EPA Project Officer: Hahn, Intaek
Project Period: December 1, 1996 through November 30, 1998
Project Amount: $247,122
RFA: Exploratory Research - Environmental Biology (1996) RFA Text | Recipients Lists
Research Category: Biology/Life Sciences , Aquatic Ecosystems
Objective:
Nonpolar lipophilic contaminants pose a severe ecological risk. Polychlorinated biphenyls (PCBs) are of particular concern because of their high persistence and bioaccumulation potential. This may be particularly acute for filter feeders due to the association of PCBs with natural particulate organic matter. The goal of this project is to examine assimilation of PCB associated with algae by an economically and ecologically important benthic species, the eastern oyster, Crassostrea virginica, and the effects of PCB exposure on the oysters' reproduction, and glycogen and lipid storage.Summary/Accomplishments (Outputs/Outcomes):
Experiments were conducted to examine: (1) PCB assimilation in sexually mature oysters fed daily 0.1 g PCB-sorbed algal paste containing 0, 0.1, or 1.0 Fg PCBs (mixture of Aroclor 1242, 1254, and 1260) for 15 and 30 days; and (2) PCB assimilation and its impact on gamete production (gametogenesis) of sexually immature adult oysters fed daily 0.7 g PCB-sorbed algal paste containing 0, 0.35, or 3.5 Fg PCBs. The effect of PCBs on glycogen reserves, lipid and fatty composition, and response of stress proteins also were assessed. PCB accumulation in oysters was found to be dose and time dependent and tissue (organ) specific. PCB accumulation in oyster tissues was positively correlated with the tissues' lipid contents. Higher PCB contents were found in organs containing the highest amount of nonpolar lipids (gonad, digestive gland and mantle). Lower PCB burdens were detected in adductor muscle and gills, tissues dominated by structural lipids. The PCB congener accumulation also differed by organ. High chlorinated congeners were preferentially accumulated in organs that are rich in non-polar lipids (gonad and digestive gland). In contrast, a high proportion of the low chlorinated congeners was found in polar lipid rich adductor muscle. PCBs were detected in the eggs of oysters fed PCB-sorbed algal paste. Considering the high lipid content in eggs (up to 300 mg/g DW), the PCB transferred from visceral mass (gonad plus digestive gland) to the eggs was relatively low.No significant impact was noted on fecundity and spawning in sexually mature oysters fed daily 0.1-1.0 Fg PCBs for 15 and 30 days. However, feeding sexually immature adult oysters daily with 0.35-3.5 Fg PCBs for 56 days appeared to impair lipid metabolism and reproduction. Compared to non-PCB exposed controls, PCB exposure resulted in fewer females and spawned females in conditioned adult oysters. There was a slight reduction in the weight percentage of certain essential fatty acids ( 20:4n-6, 20:5n-3, and 22:6n-3) in the eggs of PCB-exposed oysters. After exposure to 3.5 Fg PCBs daily for 56 days, a decrease in structural lipids (e.g., phospholipids) was also noted in gonad, adductor muscle and mantle, and glycogen in adductor muscle. In contrast, the reserve lipid, triacylglycerol, increased in digestive gland. However, PCB exposure did not elicit a stress protein response in oysters.
In summary, oysters effectively assimilated PCBs sorbed to particulate matter via feeding. PCB distribution within oyster is governed by the tissues' lipid contents. Human consumption of filter-feeders shellfish (e.g., oysters), which accumulate organic pollutants such as PCBs may pose a health hazard. PCBs dispatched in the eggs may transfer, through subsequent larvae, to higher trophic levels by predation. PCBs may cause significant impacts on filter-feeding aquatic organisms, such as oysters, as evidenced by our findings of reproduction impairments (i.e., delaying and/or inhibition of oogenesis), alteration in structural lipid synthesis and mobilization/transport of reserve lipids, and depletion of glycogen reserves in muscle. The alteration in lipid metabolism, reduction in glycogen reserves, and reproductive impairments found in PCB exposed oysters could potentially be used as bioindicators for assessing impacts of environmental pollutants in aquatic ecosystems.
Journal Articles on this Report : 3 Displayed | Download in RIS Format
Other project views: | All 12 publications | 3 publications in selected types | All 3 journal articles |
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Type | Citation | ||
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Chu FLE, Soudant P, Cruz-Rodriguez LA, Hale RC. PCB uptake and accumulation by oysters (Crassostrea virginica) exposed via a contaminated algal diet. Marine Environmental Research, Volume 50, Issues 1-5, July 2000, Pages 217-221. |
R825349 (Final) |
not available |
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Cruz-Rodriguez LA, Baucum AJ, Soudant P, Chu FLE, Hale RC. Effects of PCBs sorbed to algal paste and sediments on the stress protein response (HSP70 family) in the eastern oyster, Crassostrea virginica. Marine Environmental Research, Volume 50, Issue 1-5, July-December 2000, Pages 341-345. |
R825349 (Final) |
Exit |
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Encomio V, Chu FLE. The effect of PCBs on glycogen reserves in the eastern oyster Crassostrea virginica. Marine Environmental Research, Volume 50, Issues 1-5, July 2000, Pages 45-49. |
R825349 (Final) |
not available |
Supplemental Keywords:
exposure, effects, metabolism, sex, PCB, indicators, marine science, biology, zoology., RFA, Health, Scientific Discipline, Toxics, Waste, Ecosystem Protection/Environmental Exposure & Risk, Bioavailability, Ecosystem/Assessment/Indicators, Ecosystem Protection, exploratory research environmental biology, Chemical Mixtures - Environmental Exposure & Risk, Environmental Chemistry, HAPS, Chemistry, Ecological Effects - Environmental Exposure & Risk, Risk Assessments, Ecological Effects - Human Health, Biology, Ecological Indicators, ecological effects, ecological exposure, ecological risk assessment, contaminant transport, larvae, PCBs, developmental effects, embryos, hemocytes, polychlorinated biphenyl, oyster, polychlorinated biphenyls, ecological impacts, PCB, lipid storage, gametes, reproductive health, benthic filter feederRelevant Websites:
http://www.vims.eduProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.