Does Contaminant Accumulation Occur in Hatchery-Reared Pacific Salmonids?

Returning adult salmon and steelhead were sampled at three National Fish Hatcheries (NFHs); Warm Springs NFH (spring Chinook, Oncorhynchus tshawytscha), Quilcene NFH (coho, O. kisutch) and Quinault NFH (steelhead, O. mykiss).  Whole carcasses were taken at the Warm Springs NFH.  Additionally, muscle samples were taken on spawning days at each hatchery from both male and female fish.  Juvenile fish and feed were also collected throughout the rearing periods at each hatchery.  The tissues collected included unfertilized eggs from the females sampled; swim-up fry before feeding began; parr before they were switched from starter to crumbled feed; and smolt carcasses.  Samples were analyzed for congener specific polychlorinated biphenyls (PCBs), dioxins and furans, organochlorine pesticides, polybrominated diphenyl ethers (PBDEs) at the Geochemical and Environmental Research Group Laboratory and metals at the Alpha Woods Hole Laboratory.  Levels of the contaminants were determined in the fish at different life stages as well as in the feed they consumed during that period.  Results indicate that contaminant accumulation does vary by pollutant class as well as life stage in the hatchery reared salmonids.  For the adult fish, PBDEs were only detected in fish composites at Quilcene NFH and in adult female carcasses at Warm Springs NFH.  Levels of PCBs and PBDEs were higher in whole carcasses of adult females than in skin on fillets from females suggesting these contaminants maybe be present in greater concentrations in tissues other than muscle or skin.  Data for PCBs illustrate some variability between hatcheries for adult male composites but little variation for adult female composite samples.  Results for the juveniles will also be presented.