New research shows that several of the region’s salmon populations are bumping into temperature limits.  This includes the: Chinook salmon in California’s Central Valley and in the Columbia and Willamette River basins; Coho salmon in parts of Northern California and Oregon; and sockeye salmon that reach the Snake River Basin in Idaho.  All of these populations of salmon are on the federal endangered species list.

Warmer waters, more acidic oceans, and changed seasonal streamflow patterns are contributing to the potential decline in these populations.  These salmon populations swim upstream to spawn and are a key part of the food chain for bears, whales, and indigenous groups and fisheries along the west coast.   For salmon to successfully spawn, there needs to be the right combination of stream flows and temperatures at the right time of the year.

Maintaining the salmon populations will require significant restoration efforts which may include releasing hatchery-spawned salmon, boosting streamflows with water releases from reservoirs, and assisted migration.