Roadkill

LONGFELLOW CREEK BEGINS just north of my home in Seattle and empties into the industrial no-mans-land of the Duwamish Waterway. Along its four-mile stretch, numerous roads cross or parallel Longfellow, and on every wet Northwest day, stormwater washes into the stream carrying a mixture of toxic substances, including the compound 6PPD-quinone (6PPDq), identified as a coho killer by University of Washington and Washington State University researchers in December 2020.

In Puget Sound, scientists calculated that 60 to 90 percent of adult coho returning to urban watersheds died prematurely—as opposed to almost none in rural streams. These scientists knew that the deaths were somehow tied to stormwater runoff, where