Six years ago, scientists in the Pacific Northwest untangled a mystery about why salmon were dying in the region, often in astonishing numbers — with as many as 90% of the migrating adult coho salmon perishing in parts of Puget Sound.
The culprit turned out to be a toxic chemical from tires washing into waterways.
Now, some of the same researchers that made the 2020 discovery have confirmed that this tire-derived compound is present, at worrisome levels, in salmon-bearing watersheds in California…