A team of scientists, after years of research, identified a chemical used in making tires as a the likely culprit in frequent die-offs of coho salmon in the Pacific Northwest.
One of five salmon species in the region's waters, the fish are susceptible to an antioxidant called 6PPD-quinone that drains into waterways from nearby roads after it rains. The tire industry uses 6PPD in virtually all tires to prevent degradation and cracking. A tire industry trade group said it would collaborate with scientists to “fill knowledge gaps and determine next steps.” Researchers reported in Science that “even small doses killed coho salmon in the lab.”