Wednesday August 24, 2022
NOAA Fisheries —
Stormwater runoff containing a toxic compound from automobile tires that washes into streams is lethal to protected coho salmon, Pacific steelhead, and Chinook salmon, according to new research published today. In contrast, sockeye salmon seem largely unaffected by the same compounds.
The newly identified risk to steelhead and Chinook salmon could help inform mitigation efforts for construction and overhaul of highways on the West Coast to ensure that future runoff is less lethal to for salmon and steelhead. Some western states have already begun designing highways with inexpensive filtration measures shown to protect salmon.
“There is good news for the fish. Biofiltration appears to remove a decent amount of the toxicity,” said Barbara French, a research scientist at NOAA Fisheries’ Northwest Fisheries Science Center in Seattle. “As we learn more about the effects of roadway runoff on fish, we learn more about where these mitigation efforts are most warranted.”
The Center has been continuously investigating the causes and conservation implications of fish deaths caused by urban runoff since 2002. This research has helped us better understand untreated stormwater runoff’s scope and impact on ongoing threatened species recovery efforts, particularly in rapidly-urbanizing areas of California, Oregon, Idaho, and Washington.