High water temperatures in the Sacramento River last summer and fall caused 95 percent of naturally-spawning winter-run salmon egg and fry to die.
“I think this is really unprecedented, that we’ve seen this level of temperature mortality,” says Maria Rea with NOAA Fisheries.
She says this is the second consecutive year that the drought has had a substantial effect on the winter-run population.
“We’re just seeing a real diminishment of the cold water pool at Shasta, which is necessary to maintain temperatures. And that’s due to really low storage at Shasta,” says Rea.
Federal agencies have 600,000 hatchery-produced juvenile winter-run salmon ready for release from a federal hatchery in Northern California. That’s triple the norm. Next week they plan to release a third of them. They’re hoping to time the release of the remainder with winter storms.