Last week, 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. The case was initiated after the apparent solving of a decades-old mystery: what was causing mass deaths of endangered coho salmon in the Pacific north-west as they returned to streams to spawn. The deaths happened after heavy rain. Before dying, the fish would exhibit unusual behaviour, swimming in circles, their mouths gaping, as if gasping for air. 

Other salmon news:

• Active NorCal (Redding, Calif.): Eel River Dam sees highest chinook salmon count in 13 years
• Roseville Today (Calif.): Record salmon returns documented in Roseville area creeks
• California WaterBlog: Students take the stage at the Spinning Salmon Showcase