Salmon deaths and a tyre pollution trial

A US judge will decide if, as research suggests, a chemical tyre additive is harming endangered fish species

A coastal brown bear, also known as a grizzly bear (Ursus Arctos) carries a silver salmon or coho salmon (Oncorhynchus kisutch) that it caught. Pictured at Cook Inlet, South Central Alaska.

At the end of January a district judge in San Francisco, California, presided over a three-day trial brought by west coast fishers and conservationists against US tyre companies. The fishers allege that a chemical additive used in tyres is polluting rivers and waterways, killing coho salmon and other fish. If successful, the case could have implications far beyond the United States.

How did the case come about?