Coho Salmon Are Dying on the West Coast

Scientists have seen mass mortality events among the coho salmon after they return to streams in Washington state, where half or more die before spawning.

A study published in the journal Science found that stormwater helps carry a deadly chemical, 6PPD, from car tires to nearby creeks and streams. Tire wear releases particles that contain the new chemical 6PPD-quinone, which has proven fatal to coho salmon.

The fish play a vital role in their ecosystem and are of great cultural importance to Native American tribes. And they probably aren't the only species affected.