Dire drought warning: California says 'nearly all' salmon could die in Sacramento River
The drought is making the Sacramento River so hot that "nearly all" of an endangered salmon species' juveniles could be cooked to death this fall, California officials warned last week.
In a brief update on the perilous state of the river, the California Department of Fish and Wildlife made a dire prediction about the endangered winter-run Chinook salmon and its struggles against consistently hot weather in the Sacramento Valley.
"This persistent heat dome over the West Coast will likely result in earlier loss of ability to provide cool water and subsequently it is possible that nearly all in-river juveniles will not survive this season," the department said.
Given that the salmon generally have a three-year life cycle, a near-total wipeout of one year's run of juveniles "greatly increases the risk of extinction for the species," said Doug Obegi, a lawyer with the Natural Resources Defense Council.
The winter-run salmon endured two years of severe mortality during the last drought as well.
There are steps government agencies can take to protect fish. Beginning in April, the Department of Fish and Wildlife hauled millions of juvenile fall-run, hatchery-raised Chinook salmon to Bay Area waters as a pre-emptive move to keep them away from overly-warm river waters. Chuck Bonham, director of Fish and Wildlife, told reporters recently that his agency expects to conduct similar rescue missions as the summer heats up.
"We're going to be serving as Noah's ark," Bonham said.
Nonetheless, the warning shows how much the drought has worsened in recent months. In May, the National Marine Fisheries Service said 88% of the young Chinook salmon could perish in the Sacramento River this year. Now Fish and Wildlife said the fatality rate could approach 100%.
"Those in the salmon industry aren't terribly surprised but we are saddened," said John McManus, executive director of the Golden State Salmon Association, which represents the commercial salmon fishing industry.
Perilously warm water in the river later this year
The salmon generally can't survive when the water temperature exceeds 56 degrees. The U.S. Bureau of Reclamation, which operates Shasta Lake, is obligated to preserve cool water in the reservoir through spring and summer so that water that gets released later in the year won't cook the fish.
Environmentalists, however, say the bureau have already released so much water from the lake for farmers that the pool of cool water has gotten depleted.
Reclamation has slashed water allocations to zero for most farmers in the Central Valley this year, but it has released water from Shasta to select groups that have special water rights, including rice growers on the west side of the Sacramento Valley.
In any event, Fish and Wildlife says Shasta is heating up — which will lead to perilously warm water in the river later this year.
"Continued hot weather above 100 degrees for periods in late May, early June and past two weeks continuously will lead to depletion of cold water pool in Shasta Lake sooner than modeled earlier in the season," the agency said in this week's briefing.