Every fall, more than half of the coho salmon that return to Puget Sound’s urban streams die before they can spawn. In some streams, all of them die. But scientists didn’t know why.
Now, a team led by researchers at Washington State University and the University of Washington has discovered the answer. When it rains, stormwater flushes bits of aging vehicle tires on roads into neighboring streams. The killer is in the mix of chemicals that leach from tire wear particles: a molecule related to a preservative that keeps tires from breaking down too quickly. » More …
WSU scientists have discovered that different species of salmon have varying reactions to polluted stormwater runoff.
In a recent paper published in the journal Environmental Pollution, scientists found that coho salmon became sick and nearly died, within just a few hours of exposure to polluted stormwater. But chum salmon showed no signs of ill-effects after prolonged exposure to the same water.