Proposed Abstract Title

Persistent Pollutants in Puget Sound Juvenile Chinook Salmon: Changes after 25 years

Type of Presentation

Oral

Session Title

Toxic Contaminants in Salish Sea Biota

Location

2016SSEC

Description

Puget Sound Chinook salmon (Oncorhynchus tshawytscha) have been listed as a threatened species under the Endangered Species Act since 1999. Factors contributing to their decline include overharvest, hatchery impacts, and loss and modification of salmon habitats, including reduced habitat quality due to contaminant inputs. Since the late 1980s, NOAA Fisheries has been measuring concentrations of persistent organic pollutants (POPs) in juvenile salmon from Puget Sound, WA. Initial studies in 1986 and 1989 revealed unexpectedly high concentrations of polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethanes (DDTs), and polycyclic aromatic hydrocarbons (PAHs) in juvenile Chinook salmon or their prey from urban areas in the Sound. Over the following 25 years, there have been numerous efforts to reduce contamination in Puget Sound, includ­ing remediation and restoration of superfund sites in Elliott Bay, Seattle, WA and Commencement Bay, Tacoma WA, with associated assessment of contaminant exposure in juvenile salmon and other trust resources. In 2013, NOAA Fisheries and Washington Department of Fish and Wildlife conducted a joint study to measure concentrations of contaminants, including POPs, in juvenile salmon from five Puget Sound river-estuary systems: Skagit, Snohomish, Green/ Duwamish, Puyallup/Hylebos, and Nisqually. We compare the extent and magnitude of current exposure to concentrations measured in salmon in previous studies conducted from the late 1980s to 2006. Results indicate declines in exposure to DDTs, PCBs, and PAHs in juvenile Chinook salmon from several estuary systems, suggesting that efforts to reduce inputs of these chemicals to the Sound have had some success. However, in a significant proportion of salmon, exposure to PCBs and PAHs is still above estimated toxicity thresholds. These data establish a time series of contaminant conditions in juvenile Chinook salmon to measure the effectiveness of past and current toxics reductions strategies and actions, inform future pollution reduction efforts, and enhanced recovery of Chinook salmon.

Comments

This would be in the snapshot session on toxic contaminants in Salish Sea biota.

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Persistent Pollutants in Puget Sound Juvenile Chinook Salmon: Changes after 25 years

2016SSEC

Puget Sound Chinook salmon (Oncorhynchus tshawytscha) have been listed as a threatened species under the Endangered Species Act since 1999. Factors contributing to their decline include overharvest, hatchery impacts, and loss and modification of salmon habitats, including reduced habitat quality due to contaminant inputs. Since the late 1980s, NOAA Fisheries has been measuring concentrations of persistent organic pollutants (POPs) in juvenile salmon from Puget Sound, WA. Initial studies in 1986 and 1989 revealed unexpectedly high concentrations of polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethanes (DDTs), and polycyclic aromatic hydrocarbons (PAHs) in juvenile Chinook salmon or their prey from urban areas in the Sound. Over the following 25 years, there have been numerous efforts to reduce contamination in Puget Sound, includ­ing remediation and restoration of superfund sites in Elliott Bay, Seattle, WA and Commencement Bay, Tacoma WA, with associated assessment of contaminant exposure in juvenile salmon and other trust resources. In 2013, NOAA Fisheries and Washington Department of Fish and Wildlife conducted a joint study to measure concentrations of contaminants, including POPs, in juvenile salmon from five Puget Sound river-estuary systems: Skagit, Snohomish, Green/ Duwamish, Puyallup/Hylebos, and Nisqually. We compare the extent and magnitude of current exposure to concentrations measured in salmon in previous studies conducted from the late 1980s to 2006. Results indicate declines in exposure to DDTs, PCBs, and PAHs in juvenile Chinook salmon from several estuary systems, suggesting that efforts to reduce inputs of these chemicals to the Sound have had some success. However, in a significant proportion of salmon, exposure to PCBs and PAHs is still above estimated toxicity thresholds. These data establish a time series of contaminant conditions in juvenile Chinook salmon to measure the effectiveness of past and current toxics reductions strategies and actions, inform future pollution reduction efforts, and enhanced recovery of Chinook salmon.