Alaska salmon may bear scars of global warming

Kenneth R. Weiss in the Los Angeles Times: …More Alaskan salmon caught here end up in the dog pot these days, their orange-pink flesh fouled by disease that scientists have correlated with warmer water in the Yukon River. The sorting of winners and losers at Moore's riverbank fish camp illustrates what scientists have been predicting will accompany global warming: Cold-temperature barriers are giving way, allowing parasites, bacteria and other disease-spreading organisms to move toward higher latitudes.

"Climate change isn't going to increase infectious diseases but change the disease landscape," said marine ecologist Kevin D. Lafferty, who studies parasites for the U.S. Geological Survey. "And some of these surprises are not going to be pretty."

The emergence of disease in Alaska's most prized salmon has come as a shock to fishermen and fisheries managers. Alaskan wild salmon has been an uncommon success story among over-exploited fisheries, with healthy runs and robust catches that fetch ever higher prices at fish markets and high-end restaurants in Los Angeles, New York, Tokyo and London…..

….Mary Ruckelshaus, a federal biologist with the Northwest Fisheries Science Center in Seattle, has been running climate models to peer into the future for Pacific Northwest salmon. Those models predict that salmon will become extinct without aggressive efforts to preserve the clear, cool streams needed for spawning, such as planting trees to shade streams and curtailing the amount of water siphoned off by farmers. "It's sort of a time bomb," Ruckelshaus said. "If people don't have a plan for it, it can be disastrous when it hits."

Coho salmon Based on the drawing from silver or coho salmon, adult male. In: "The Fishes of Alaska." Bulletin of the Bureau of Fisheries, Vol. XXVI, 1906. P. 360, Plate XXXI. which is at http://www.photolib.noaa.gov/fish/fish3009.htm. Wikimedia Commons