Continued River Warming Could Kill Fishby Anna King, Herald staff writer
Tri-City Herald, March 24, 2005
If global warming doesn't slow, rivers like the Columbia, Yakima and Snake could become too hot for salmon, steelhead and trout by 2040, Northwest Wildlife Federation officials said Wednesday.
Research for the conservation group by University of Washington scientists said about 20 percent of the Pacific Northwest's rivers could be affected. The report also said higher temperatures could alter snowpack and rain that feeds steam flows that fish depend on.
"When streams get too warm, the fish can experience slower growth rates, lower oxygen levels in the water, and greater susceptibility to toxins, parasites, and disease," the report said.
The situation adds to an already difficult struggle for many species of fish.
"Salmon in the region are struggling to survive amidst dams, water diversions and development along river shorelines," said Paula Del Giudice, Seattle-based director of the federation's Northwest Natural Resource Center, in a news release. "Global warming will add an enormous amount of pressure onto what's left of the region's prime cold-water fish habitat."
Del Giudice said the drought provides a good example of what could become more common.
The report said a 3-degree increase in average August temperatures in the Pacific Northwest would render the rivers too warm for fish. The report is based on recent global warming projections that show such a temperature increase is likely by 2040 because of increasing pollution from fossil fuels such as coal and oil.
Conservation group officials said other rivers at risk include the Snohomish, Snoqualmie and Skykomish rivers in Washington, and the Deschutes, John Day, Klamath and Rogue rivers in Oregon.
Patty Glick, a federation climate specialist, said that global warming could make snow accumulation scant, especially on the west slopes of the Cascades. Glick said her climate models show the region could face a 50 percent decline in average snowpack in the next 45 to 75 years.
"The current drought hitting the region is very much consistent with what scientists expect to happen in the Pacific Northwest if global warming is left unchecked," Glick said. "This is our wake-up call. We need to do whatever we can now to minimize further changes in climate and improve the resiliency of the region's rivers and fish."
Lonnie Osterholm said the volume and temperature of water flowing down the Columbia and Snake rivers affects his business daily. He owns Spokane-based Fish Tales Guide Service and has spent his life on the rivers and lakes of the Pacific Northwest.
Osterholm said he has seen the effects of this year's drought -- spring chinook salmon are late in their migration up the Columbia River.
"Those fish are sitting out in the ocean waiting for the spring runoff," he said. "They are not going to get it this year. There was no snow melt, so the fish are confused."
The chinook wait for a large outflow of water before heading upstream, he said.
But Osterholm said the real problem with this year's water supply will show up better in about four years. That's when the tiny fish that try to swim out to sea this year will return. But he said if dam operators use the spring's limited flow for power instead of spilling it over the dam to help tiny fish make their way to sea, fishing could be dismal.
"The whole problem is not the fish coming up; the problem is the smolt getting down," he said.
Today, regional utilities representatives and Bonneville Power Administration officials will announce how they plan to deal with the dry weather on the hydroelectric system and power rates.
Whatever they decide, Osterholm said he and others will likely feel the effects.
"People hear that it's bad and they start canceling," he said.
Often when the water is warm, the fish will hang out downstream and not migrate up into the popular fishing stretch on of the Columbia's Hanford Reach, he said.
Tribal fishermen also are concerned.
"They are meeting at the reservations already to discuss what the ramifications will be," said Jeremy Fivecrows, spokesman for the Portland-based Columbia River Inter-Tribal Fish Commission. "If the past is any indication, the whole hydro system is built on providing electricity. And the salmon don't seem to be as high a priority to some people."
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