Center for Biological Diversity

For Immediate Release, June 15, 2023


Emily Jeffers, (408) 348-6958,

Lawsuit Launched Over Failure to Protect Salmon From Toxic Tire Chemical

OAKLAND, Calif.— The Center for Biological Diversity filed a formal notice today of its intent to sue the Oregon and California state transportation agencies for failing to consider fatal impacts to salmon from toxic tire pollution.

Neither the California Department of Transportation nor the Oregon Division of the Federal Highway Administration considered the effects of this deadly chemical when authorizing hundreds of road-maintenance projects in salmon habitat throughout Oregon and California.

“We’ve known for years now that tire pollution is killing Pacific salmon, but transportation agencies haven’t done anything about it,” said Emily Jeffers, a senior attorney at the Center. “Salmon are already threatened by drought and loss of habitat, and now it’s clear our commutes and road trips are making it even harder for the species to survive. To give coho salmon a fighting chance, we need action from the top to get this chemical off our roads and out of our waterways.”

A groundbreaking 2021 study found that a single chemical, 6PPD, was responsible for storm-related salmon die-offs in urban areas. A dangerous pollutant, 6PPD rubs off car tires through normal wear and tear. During rainstorms, the chemical washes from roadways into streams, where it contaminates water and leads to the death of coho salmon by attacking their cardiopulmonary system.

In response to the study, 14 members of Congress sent a letter to the National Marine Fisheries Service in 2021 requesting that the agency act with “great urgency” to “take any necessary actions” to address the threat posed by 6PPD. The Service responded by outlining research and precautionary steps the agency had planned, but also cited as hurdles a lack of long-term funding and staffing challenges.

Under the Endangered Species Act, agencies such as Caltrans and the Department of Transportation must consult the National Marine Fisheries Service if their projects will affect listed salmon, which includes the coho. If new information comes to light, the agencies must reconsider the effects the projects may have on listed species, which they did not do in response to the 2021 6PPD study.

Scientists have recently found that 6PPD is many times more toxic to coho salmon than previously thought; this year they determined that it’s also toxic to other important fish, like threatened and endangered populations of Chinook salmon and steelhead trout.

Critically endangered Southern Resident killer whales are also indirectly threatened by 6PPD. The orcas rely on coho as a primary food source and face starvation when salmon populations are low. According to the Fisheries Service, there is also a “high potential” for marine mammals to bioaccumulate the chemical by eating salmon.

The Center for Biological Diversity is a national, nonprofit conservation organization with more than 1.7 million members and online activists dedicated to the protection of endangered species and wild places.

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