POPs in Prey of Killer Whales (Regional patterns of persistent organic pollutants of five Pacific salmon species (Oncorhynchus spp): implications as a food supply to southern resident killer whales (Orcinus orca) and other apex predators)

The purpose of this project is to assess the extent to which persistent organic pollutants (POPs) accumulate in adult Pacific salmon, with emphasis on Chinook salmon (O. tshawytscha) and the potential adverse effects these contaminants pose to the health of southern resident killer whales (SRKW). The Ecotoxicology Program, in collaboration with the Environmental Assessment Program and staff from the Washington Department of Fish and Wildlife, is conducting a coast-wide assessment of POPs in five species of Pacific salmon over the geographic range where they would be routinely encountered by resident killer whales. Concentrations of six classes of POPs have been measured in Chinook salmon from six populations originating from streams along the West Coast of North America, ranging from northern British Columbia to Puget Sound and northern California. Additionally, major population-complexes or multiple, geographically-separated population-complexes of sockeye (O. nerka), coho (O. kisutch), pink (O. gorbuscha) and chum salmon (O. keta) were sampled to provide a comparison of POPs among Pacific salmon (Oncorhynchus spp.). Major findings will be submitted to a peer-reviewed journal.

The Northwest Regional Office of Protected Resources uses this information to assess the threat that contaminants pose for southern resident killer whales and to guide recovery efforts for reducing whales' contaminant exposure. This project was originally designed as a stand-alone project; however, additional Chinook salmon populations were sampled recently, and will be incorporated into the analyses. The project is one component of a larger Killer Whale Prey project that assesses the quality of prey of southern resident killer whales in terms of their contaminants and energetic content. Measures organic pollutants in prey of killer whales, with particular emphasis on Chinook salmon and other species of Pacific salmon.