Category: Fish/Shellfish Research
Published: April 30, 2018
Publication number: FPT 20-11
Author(s): Sandra O’Neill, Eric Kinne, Catie Mains, Brian Missildine, Jill Cady
Following the decline of the Southern Resident Killer Whale population, Governor Jay Inslee signed Executive Order 18-02. The purpose of this report is to respond to the Governor’s request for Washington Department of Fish and Wildlife (WDFW) to investigate the potential of hatchery feed as a contributing source of Polychlorinated biphenyls (PCBs) found in Southern Resident Killer Whales.
Research indicates that hatchery feed is not a significant source of PCB contamination in adult Chinook salmon that originated from WDFW hatcheries. Hatchery feed contains low concentrations of PCBs. In addition, juvenile salmonids have trace amounts of PCBs through maternal transfer. Most (96% – 99%) of the PCBs in adult salmonids is acquired in the marine environment in which they migrate and live.
The amount of PCBs in adult salmon that is acquired in the freshwater environment, including hatcheries, varies from approximately 1% in undeveloped rivers to 4% in developed river where outmigrating juvenile fish acquire more PCBs. Hatchery feed is estimated to contribute a maximum of 1% of the PCBs measured in adult Chinook from Puget Sound that originated in hatcheries.
WDFW is actively engaged with researchers, other government agencies and fish feed manufacturers to identify detectable PCBs in fish feed and will pursue alternative feed options that contain the lowest concentration of PCBs when feasible and cost-effective to do so.