A new study funded by and focused on King County, Washington, aims to go beyond the sensational “salmon on cocaine” headlines to get us closer to understanding what chemicals in wastewater means for the life cycles of salmon and orcas that eat them. It has become a frequent topic of discussion within state government — especially after the Governor’s Orca Task Force made reducing exposure to pollution a top priority.
Over the next year, researchers will explore how effluent from King County’s three largest plants and nearby waters affect orca prey species and orca exposure.
The researchers will collect effluent from the West Point, Brightwater and South plants and water from nearby drainage outfalls, then send it to a lab to get a breakdown of the compounds in it. In the spring, they’ll expose juvenile chinook salmon from a hatchery to effluent mixtures at a laboratory in Puyallup run by Jen McIntyre, assistant professor in the School of the Environment at Washington State University.
“We will dilute the treatment plant effluent with clean water to simulate for fish exposure to different ‘strengths’ of effluent from the treatment plant, such as occurs in receiving water,” McIntyre says.
Beyond measuring bioconcentration of chemicals and evaluating for impacts both acute (death) and chronic (limited growth and reproduction), they’ll be studying biomarkers in the blood and liver that can show subtle negative health impacts, including metabolic, endocrine or behavioral disruption.
Find out more