We've almost never caught a salmon south of those temperatures in warmer waters. That in turn would cause the North Pacific Ocean to warm by as much as 6 degrees Fahrenheit. If the models prove correct, Welch says the colder water that salmon prefer would no longer be found in the North Pacific. They were up in the Bering Sea. Of course, Welch's predictions depend to a great extent on just how much the North Pacific Ocean actually warms up.
Scientists caution that the models used to predict climate change are imperfect.
Still, scientists generally agree that David Welch is on to something. Last year's El Nino brought warmer ocean conditions to the North Pacific, and fewer salmon returned to their spawning grounds throughout the North Pacific. Milo Adkison is a fisheries professor at the University of Alaska Fairbanks. The reason it's worrisome is if you get global warming then the habitat disappears. We could lose large populations of salmon.