The Snake River Basin Ecosystem
The mighty Snake River flows through diverse habitats in Wyoming, Central Idaho, Southeast Washington, and Northeast Oregon. Powerful forces of nature—volcanoes, flooding episodes and glaciers—shaped the basin. The Snake River has over twenty major tributaries, most of them in mountains of the basin. Its best-known feature is Hells Canyon—North America’s deepest river gorge. Its iconic species is the salmon. Key portions of the basin provide the largest, highest, and most intact salmon habitat of the lower 48 states, and it also supports other imperiled species. If conservation measures are implemented, this ecosystem could be an important refuge for endangered species in a time of climate change.
A Home for Threatened & Endangered Species
The Snake River is home to four imperiled runs of anadromous fish—steelhead, spring/summer Chinook, fall Chinook, and sockeye salmon (the most endangered salmon on earth). Snake River salmon and steelhead climb 7,000 feet and swim almost 1,000 miles from the Pacific Ocean to their natal streams. (No other salmon or steelhead goes as high and as far, making them truly unique in the world.) The threatened bull trout overwinters in the Snake River, while native and resident fish species of concern also live in the Snake and its tributaries. The river is also home to dozens of rare and endemic mollusks, with at least 21 snail and clam species of special concern.
Snake River salmon also carry nutrients from the oceans to inland rivers, forests and other species. They and their Columbia River cousins are the primary food source for the endangered and distinct Southern resident killer whales. Some of America’s great carnivores—the grizzly bear, gray wolf, wolverine, and Canada lynx—rely on this ecosystem and its salmon. The basin’s salmon-enriched habitat is home to more than 200 bird species, including whooping cranes, bald eagles, peregrine falcons, greater sage-grouse, and yellow-billed cuckoos.
Climate Change Threats
Recent analyses indicate that rivers are warming faster than surrounding air temperatures. These warmer waters, as well as the scouring of salmon nests and other changes in habitat, are putting threatened and endangered fish on the front lines of climate change, particularly in the Pacific Northwest. Since salmon and steelhead require clear, cold water, ensuring that salmon can migrate to the coolest tributaries in the basin is vital to their survival and reproduction. Fortunately, the mountainous areas of the Snake River Basin are projected to remain fairly cool in a warming world, so they could be refuges for salmon and steelhead in the whole Columbia River Basin. Since their survival is vital to the ecosystem and its species, the basin could also be a highly valued refuge for dozens of other threatened and endangered species.
Needed Conservation Measures
The potential for the Snake River Basin ecosystem to serve as a climate change haven highlights the need to remove four federal dams on the lower Snake River to ensure the survival of the basin’s imperiled salmon and steelhead. Removal of these dams would restore more than 140 miles of free-flowing habitat that are spawning grounds for threatened Snake River fall Chinook salmon and would open up the remaining 70% of potential habitat that scientists describe as a “Noah’s Ark” for salmon. Fishermen, outdoor retailers, scientists, conservationists, clean energy advocates, taxpayer groups, eastern Washington farmers, the State of Oregon, Members of Congress, and Native American Indian tribes support the protection and restoration of the Snake River Basin habitat. Restoring access to this habitat would also create jobs and economic prosperity. Moreover, it would leverage existing federal resources for already protected areas that are in generally excellent condition. Therefore, after the initial investment to remove the dams, the fish will return to habitats that require little investment in restoration.