California Heat Wave Could Kill All Young Salmon in Sacramento River

U.S.|California’s heat wave could wipe out all of the young salmon in the Sacramento River.

• July 15, 2021, 12:15 p.m. ET

Abnormally warm water from the punishing heat that has settled on much of the West this summer and a lack of water during the worst drought in decades are threatening the endangered Chinook salmon population in the Sacramento River, officials said this week.

The California Department of Fish and Wildlife said the river, which flows more than 400 miles from the northern mountains through the state’s capital city, is facing a “near-complete loss” of young salmon, which cannot grow beyond their egg stage in waters heated by extended temperatures of over 100 degrees.

“It’s an extreme set of cascading climate events pushing us into this crisis situation,” Jordan Traverso, a spokeswoman for the California Department of Wildlife and Fish, said in a statement.

To save as many as possible, officials transported millions of juvenile salmon to San Pablo Bay, San Francisco Bay and other seaside net pens in recent days. The truckloads of fish will “ensure the highest level of survival for the young salmon on their hazardous journey” to the Pacific Ocean, Ms. Traverso said.

A series of summer heat waves across the Western United States and Canada are already responsible for the death of hundreds of millions of marine animals this summer.

“Extreme heat and near-record lack of precipitation are putting unprecedented stress on ecosystems and species, including our iconic Chinook salmon,” Lisa Lien-Mager, a spokeswoman for the California Natural Resources Agency, said. “The challenges are great, but a complete die-off of in-river juvenile winter-run Chinook salmon is not a certainty this year and we are working hard to mitigate that risk.”