The one thing that I am sure of is that if global warming continues it absolutly will have a major effect on salmon. Salmonids are harmed by water temperatures in excess of roughly 17 C. and cannot survive in rivers that exceed roughly 19 C. (This varies with the timing of the temperature peaks and the life phase of the fish.) Some rivers occassionally come close to those temperatures now. If we add a few degrees to those rivers the runs will decline or perish.