A federal lawsuit has been filed by West Coast fishing groups against 13 major tire manufacturers over the use of a chemical, 6PPD, in their products that is allegedly harming endangered salmon and oceangoing trout. The lawsuit claims that the tire makers have violated the U.S. Endangered Species Act by discharging 6PPD-quinone into rivers, which is derived from a preservative that helps tires last longer. The chemical has been linked to the mortality of coho salmon returning to Puget Sound streams, and it is alleged to be harming other salmon and steelhead populations as well. The complaint filed by the Pacific Coast Federation of Fishermen's Associations and the Institute for Fisheries Resources identifies two dozen species of salmonids along the West Coast that have been impacted by the chemical. Research has shown that 6PPD-quinone kills 40% to 90% of coho salmon returning to certain urban streams before they can spawn. The lawsuit comes after the Environmental Protection Agency announced a review of the chemical's use in tires.