Pacific Northwest Salmon in Hot Water

Most Threatened Pacific Northwest Rivers At Risk from Global Warming

03-18-2005 // Christine Dorsey

"Changing Our Rivers Like Never Before"

SEATTLE, WA -- By 2040 up to 20 percent of the Pacific Northwest could become too warm for salmon, steelhead and trout if global warming is left unchecked, an analysis released today by the National Wildlife Federation shows.

Ongoing research conducted by the University of Washington indicates that higher regional temperatures could also change the timing and volume of rain and snow coming from nearby glaciers and mountains, affecting stream flows that the fish have historically depended on.

"Salmon in the region are struggling to survive amidst dams, water diversions and development along river shorelines," says Paula Del Giudice, director of the National Wildlife Federation's Northwest Natural Resource Center in Seattle. "Global warming will add an enormous amount of pressure onto what's left of the region's prime cold-water fish habitat. If we don't act now to curb pollution, within our lifetimes a significant portion of this region's salmon, steelhead and trout could be pushed out of existence. We have a responsibility to protect this region's wildlife heritage for our children's future. That means we must unite in confronting global warming starting now."

A 3º F rise in average August temperatures in the region could cause as much as 20 percent of the area containing suitable habitat for some cold-water fish in the Columbia River Basin and coastal watersheds of Washington and Oregon to reach nearly 70 degrees F. If translated to stream temperature, the area could become highly stressful for salmon, steelhead, and trout, concludes the report, Fish Out of Water. Based on recent global warming projections, a 3º F rise in temperature is plausible by 2040 due to increasing pollution from fossil fuels such as coal and oil. If streams in the region continue to be degraded by other factors, the impact will likely be even greater.

Regionally, the rivers most at risk include the Columbia, Snohomish, Snoqualmie, Skykomish, Snake and Yakima rivers in Washington; the Snake River in Idaho and the Deschutes, John Day, Klamath, and Rogue rivers in Oregon. Important rivers to keep an eye on include the Skagit, Hoh and Queets in Washington, the Sandy in Oregon and the Salmon in Idaho.

In Fish Out of Water, National Wildlife Federation climate specialist Patty Glick reports that scientists project that global warming could bring a substantial decline in snow accumulation in the Pacific Northwest--especially the west slopes of the Cascades, the Olympics, and the coastal range--in the coming decades. Regional climate models project that the region could see an additional 50 percent decline in average snow pack in the next 45 to 75 years, significantly reducing the primary source of water for the region during dry summer months.

"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 says."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."

The Pacific Northwest already is beginning to feel the effects of global warming. Regional temperatures increased 1.5° F on average during the 20th century, increasing at a faster pace than the global average; and annual precipitation has increased by 14 percent, but mostly in the form of rain. Peak snow fall and snowmelt-derived stream flow across the region have shifted by 10 to 30 days earlier since the mid-1900s, and snow pack has decreased 11 percent over the same period.

"This isn't just bad news for fish," Del Giudice says. "It spells trouble for all of us who depend on water from these rivers for irrigation, hydropower and drinking. As the region's climate shifts, we could find that our water resources are less reliable, with water arriving earlier in the spring and dwindling during the heat of summer. We're changing the character of our rivers and the region like never before. The wildlife legacy we leave behind for future generations depends on the action we take today to confront global warming."

Scientists project that average annual temperatures in the region could rise by an additional 0.9 to 4.7° F by the 2020s and 2.7 to 5.7º F by the 2040s, contributing to higher stream and estuary temperatures.

Global warming also is contributing to the rapid retreat of many of the region's glaciers, which provide a regular and dependable source of water to some of the Northwest's major rivers in late summer and fall. The majority of Washington's 950 glaciers are receding rapidly, and several have disappeared in the past few decades. Similar trends are occurring on other glaciers throughout the region.

Glick says reducing carbon dioxide pollution from the burning of fossil fuels is the number one solution to global warming. Meanwhile, strengthening fish populations by protecting some of the more pristine rivers and reducing other manmade threats such as dams and water diversions for crop irrigation is essential to the long-term viability of the region’s cold-water fish species.

The National Wildlife Federation is America's conservation organization protecting wildlife for our children’s future.

For a copy of the report, see "Related Documents."

Contacts: Christine Dorsey - 202-979-6806 or 703-470-6689,
Patty Glick - 206-285-8707, ext. 104,


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