A broad-scale assessment of toxic contaminants in Dungeness crabs (Metacarcinus magister) and spot prawns (Pandalus platyceros) from Puget Sound, Washington

Abstract

Dungeness crab (Metacarcinus magister) and spot prawn (Pandalus platyceros) are two common, abundant, and ecologically important benthic crustaceans that support valuable recreational, subsistence, and commercial fisheries in Puget Sound. The purpose of this study was to evaluate the geographic extent and magnitude of toxic contaminants in these two species throughout eight Puget Sound basins and three urbanized embayments as sub-locations; Elliott Bay (Seattle), Sinclair Inlet (Bremerton), and Commencement Bay (Tacoma). Data generated from this study were also provided to the Washington Department of Health for their human health risk assessment of these species. Two hundred forty Dungeness crabs were collected at 54 stations, generating 56 crab muscle and 19 crab hepatopancreas composites while 777 spot prawns were collected at 42 stations, generating 43 spot prawn muscle and 16 spot prawn head-tissue composites. Persistent organic pollutants (POPs) including polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), polycyclic aromatic hydrocarbons (PAHs), and organochlorine pesticides as well as six metals (mercury, arsenic, cadmium, copper, lead and zinc) were analyzed in the crab and prawn tissues. Generally, the highest concentrations of POPs were observed in urban areas while most metals were found at varying levels in Dungeness crab and spot prawn muscle throughout Puget Sound. Total PCBs in muscle tissue from both species ranged from the limit of quantitation (roughly 0.85 ng/g ww) to 12 ng/g ww in non urban locations and from 14 to 180 ng/g ww in the three urban areas. PBDEs (sum of 11 congeners) and PAHs (sum of 37 analytes) in muscle tissue were low overall with all concentrations less than 6 ng/g ww. With the exception of a few metals, contaminant concentrations in the hepatopancreas of Dungeness crab and head tissue of spot prawn were as much as 36 times higher than the concentrations reported in corresponding muscle samples, suggesting POPs were being concentrated in the primary detoxifying organ in these species. This first time broad-scale Puget Sound wide assessment of these two crustaceans provides vital information into how contaminants are geographically distributed throughout the area and how they accumulate in these two important species of the Puget Sound food web