Puget Sound Toxic Pollution

In Puget Sound, 45 percent of river systems show levels of toxic chemical pollution that increase health risks to juvenile Chinook salmon (Results Washington 2018). As they grow, Puget Sound Chinook salmon accumulate toxic chemicals, which pose health risks to predators, including southern resident orcas. Most toxic pollution in Puget Sound is carried by stormwater that runs off paved roads and driveways, rooftops, yards, and other developed lands. These contaminants can reduce growth, increase disease susceptibility, and alter hormone production, all of which can reduce the survival of salmon. The greatest risks occurred in three highly developed watersheds–the Duwamish River, Hylebos/Puyallup, and Snohomish River systems.

Stream Flows In Puget Sound Are in Flux

When there is less rain and warmer temperatures in the summer, some of the streams have less water and can be too warm for fish to survive and reproduce. Low water levels can reduce the amount of habitat, food, and water quality for salmon. In Puget Sound, low water levels in the summer have remained consistent with the regional target or have improved. Although stream flows have improved over the long-term, they have improved only slightly in the past several years.

View statewide data on Water. Visit the Salmon Data Hub for more of the data behind the indicator charts and graphs used throughout this site.