FYI. I just came across this. Perhaps automotive oil, diesel, antifreeze, or combinations of many hydrocarbons at ppm that coho are extremely sensitive to. http://www.kitsapsun.com/news/2013/jan/21/mystery-compound-found-to-kill-coho-salmon/#axzz2Ij8S6P5D Interestingly dogs (most especially beagles) are very sensitive to chemotherapeutics in clinical trials for humans so dogs are not typically used to test toxicity during pre clinical testing. Rats - monkey - human.