Polychlorinated dibenzo-p-dioxins and dibenzofurans and dioxinlike polychlorinated biphenyls in sediments and mussels at three sites in the lower Great Lakes, North America.
Levels of contaminants including polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), non-ortho-substituted and mono-ortho-substituted dioxinlike polychlorinated biphenyls (DLPCBs) were determined in sediments and freshwater mussels (Dreissena spp. and Elliptio complanata) at three sites in the lower Great Lakes (North America). Impacts of mussel colonization on sediment quality were investigated by comparing contaminant levels in colonized sediment with levels in sediment in the same area that was not colonized, but exposed to similar environmental conditions. Significant impacts on contaminant levels of colonized sediment, compared to noncolonized sediment, were observed at two sites exhibiting high mussel population densities (Fort Erie, eastern Lake Erie, ON, Canada, 2.2 kg/m2 dry wt biomass, and Port Dalhousie, western Lake Ontario, Ontario, Canada, 6.1 kg/m2 dry wt biomass); these differences were not observed at a site with lower mussel densities (Bay of Quinte, eastern Lake Ontario, Ontario, Canada, 0.7 kg/m2). Total organic carbon and contaminant concentrations were statistically significantly greater in colonized sediment, compared to noncolonized sediment, at the two impacted sites. Areal estimates of PCDD/PCDF and DLPCB toxicity equivalents (TEQs) in mussel biomass at the three sites averaged 0.16% and 3.3%, respectively, of the TEQs in the top 3 cm of sediment, indicating that the sediments were the primary sink for contaminants. The observed differences between colonized and noncolonized sediment suggest that Dreissena are capable of influencing the chemical properties of sediment they colonize.
Aquatic Ecosystem Management Research Branch, National Water Research Institute, Environment Canada, Burlington, Ontario. chris.marvin@ec.gc.ca
Christopher H
CH
Marvin
E Todd
ET
Howell
Terry M
TM
Kolic
Eric J
EJ
Reiner
D000818:Animals; D001572:Benzofurans / Q000032:analysis*; D018533:Biomass; D049872:Bivalvia / Q000737:chemistry*; D002244:Carbon / Q000032:analysis; D000072338:Dibenzofurans, Polychlorinated; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry*; D006114:Great Lakes Region; D011078:Polychlorinated Biphenyls / Q000032:analysis*; D014018:Tissue Distribution
D001572:Benzofurans; D000072338:Dibenzofurans, Polychlorinated; D002244:Carbon; D011078:Polychlorinated Biphenyls