Low snowpack means hot water for Spring Chinook salmon
The Western Front
March 12, 2015
The lack of snowpack will cause trouble for Whatcom County salmon this summer.
With less snowmelt, the south fork of the Nooksack River will be much more shallow, meaning higher than average water temperatures in the late summer.
“It’s bad news for salmon,” said James Helfield, professor of environmental science. This is because salmon are cold-water fish.
When water temperatures climb above 63.6 degrees Fahrenheit, it negatively affects the salmon’s metabolism.
The warmer water also doesn’t allow for as much oxygen to dissolve. This causes a problem called hyperoxia in the salmon, Helfield said.
The combination of stress on salmon’s metabolism and lower oxygen levels weaken the salmon’s immune system, making them more susceptible to parasites and diseases, he said.
“The projection is for continuing winters of lower snowpack in the Cascades and Olympics,” Dr. David Beatty of the Nooksack Salmon Enhancement Association said in an email.
“The snowpack effect can coincide with ocean changes affecting temperature, currents, upwelling effects on food supply,” Beatty said. “There will be effects on all freshwater life stages of salmon.”
One or two mild winters is just weather, but more than that means a steady pattern of more mild winters in the Northwest, he said…