Unusually warm waters in the Columbia River Basin have prompted federal officials to invoke measures to help migrating fish survive the hostile conditions.
A federal plan to protect endangered salmon and steelhead, known as the BiOp (or biological opinion), has contingencies for drier, warmer years. That includes the release of cooler water from upstream reservoirs.
So far, extra water has been released from reservoirs in Canada, Montana, and Lake Roosevelt in Washington.
Ritchie Graves, the Columbia hydropower branch chief with NOAA Fisheries, said the Salmon River in Idaho has been at near-fatal temperatures for sockeye salmon, recently reaching 76 degrees. Managers have started trucking fish to hatcheries in Boise to keep them out of the warm water.
“This is just a rough condition for fish everywhere in the basin," Graves said.
That includes pretty much all watersheds throughout the Northwest. Environmental groups are calling for salmon and trout fishing closures in all West Coast rivers that are warmer than 64.4 degrees. The groups say catch-and-release and commercial fishing techniques harm salmon, especially when they are already stressed out by warm waters.
“These extreme conditions put a lot of pressure on our region’s threatened and endangered wild salmon and steelhead,” Kurt Beardslee, executive director of Wild Fish Conservancy, said in a news release. “In the face of our current seasonal heat crisis, pressure on wild populations must be reduced now. At this point in time, the only means of achieving this is through a reduction in harvest or fishing.”
A recent study found that up to 35 percent of fish caught and then released die a short time after they are returned to the water.