One day after schoolchildren released coho smolts into Byrne Creek in SE Burnaby, BC, fish were found dying. Studies show that coho are particularly sensitive to road wash that contains a toxic combination of pollutants including gasoline, oil, antifreeze, and metals.
They actually try to swim with their heads above the water as they try to escape the pollutants
It would likely help if the City of Burnaby council would actually implement the Byrne Creek Integrated Stormwater Management Plan and the Environmental Sustainability Strategy.
The watershed needs rain gardens, swales, and biofiltration ponds. The more road wash that is intercepted and naturally filtered in the ground the better.
UPDATE: I sent this to Dr. Jenifer McIntyre, a professor at Washington State University, who has been researching the impacts of road runoff on salmon. She shared a link to her latest published study comparing road runoff effects on coho vs chum.