A plan by the U.S. Environmental Protection Agency identifies cold-water refuges in Columbia River tributaries where adult salmon and steelhead can rest as they migrate from the ocean.
Cold-water habitat will be critical for fish in a warming world; finding and protecting those places now is a priority.
A warming climate, habitat degradation, and predation by an introduced species threaten native bull trout in Montana, but a joint effort involving Montana, the Salish and Kootenai Tribes, and an an international agreement with British Columbia aims to protect and restore the cold-water species.
Like people seeking shade outside on a hot day, salmon and steelhead look for pockets of cold water as they migrate home from the ocean to spawn, a search that will become increasingly important, and perhaps more difficult, as the climate warms.
Water scientists are searching the Columbia River Basin for the cold-water places where salmon can rest when the water temperature goes lethal.
Changes could threaten aquatic ecosystems, alter key habitat conditions for salmon and other cold water species and, potentially, warm water to lethal temperatures for fish.