http://droughtreporter.unl.edu/

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In July 2021, the California Department of Fish and Wildlife predicted that “nearly all” of the endangered Chinook salmon juvenile population would likely die from warm water in the Sacramento River in 2021. The prediction came true. An estimated 2.6% of the winter-run Chinook salmon juvenile population were able to survive the warm water temperatures, according to the CDFW. Another factor was at play regarding the young fish. Many were deficient in thiamine, or vitamin B1, due to adult salmon binging on anchovies, causing a breakdown in thiamine levels, which was passed along to the juveniles. Environmentalists charge that the massive fish kill was caused by mismanagement of the river last spring when the U.S. Bureau of Reclamation sent hundreds of thousands of acre-feet of water from Shasta Lake to farmers with special water rights. The Sacramento Bee (Calif.), Jan 3, 2022 Only 2% of winter-run Chinook juvenile salmon likely survived the summer, due to high water temperatures which led to massive fish kills in the Sacramento River, according to the California Department of Fish and Wildlife. Not even during previous years of drought have so many juvenile salmon died, raising the specter of permanent collapse of the endangered species. An estimated 75% of winter-run Chinook eggs died from heat this summer on the upper Sacramento River. Experts think that nearly all the remaining salmon that did hatch soon died from a combination of low river flows and natural or human-caused mortality. Courthouse News Service (Pasadena, Calif.), Nov 4, 2021 Drought is heating up the Sacramento River to the point that nearly all endangered winter-run Chinook salmon could perish this fall, warned officials from the California Department of Fish and Wildlife. The salmon typically have a 3-year life cycle, so the deaths of nearly all of one year’s run of young “greatly increases the risk of extinction for the species,” according to a lawyer with the Natural Resources Defense Council. California’s last drought also caused two years of severe mortality among winter-run salmon. The pool of cool water in Shasta Lake has been depleted as the U.S. Bureau of Reclamation released water for farmers. The Sacramento Bee (Calif.), July 8, 2021