SAN FRANCISCO (AP) — Baby salmon are dying by the thousands in a California river, and a whole host of endangered salmon could be wiped out in another. Fishermen who live off adult salmon, once they enter the Pacific Ocean, are raising alarm bells as scorching heat waves and prolonged drought in the western United States raise the temperature of the water and endanger fish from Idaho to California.

Hundreds of thousands of young salmon are dying in the Klamath River in northern California as low water levels caused by drought allow a parasite to thrive, devastating a Native American tribe whose diet and traditions are related to fish. And wildlife officials said the Sacramento River is facing an “almost complete loss” of young chinook salmon due to abnormally warm water.

A crash in a class of young yearling salmon can have lasting effects on the total population and shorten or halt the fishing season, a growing concern as climate change continues to make the West hotter and drier. This could be devastating for the commercial salmon fishing industry, which in California alone is worth $1.4 billion.

Falling catches have already led to soaring retail salmon prices, hurting customers who say they can no longer afford the $35 a pound of fish, said Mike Hudson, who has spent the past 25 years catching and selling fish. sell salmon at Berkeley Farmers Markets.

Hudson said he considered retiring and selling his 40ft (12m) boat because “it’s going to get worse from here”.

Winter Chinook salmon are born in the Sacramento River, travel hundreds of miles to the Pacific, where they normally spend three years before returning to their birthplace to mate and lay their eggs between April and August. Unlike the fall Chinook which survives almost entirely on hatchery breeding programs, winter salmon are still largely farmed in the wild.

Federal fisheries officials predicted in May that more than 80% of baby salmon could die due to warming water in the Sacramento River. Now, state wildlife officials say that number could be higher amid a rapidly depleting freshwater pool in Lake Shasta. California’s largest reservoir is only about 35% full, federal water managers said this week.

“The pain we’re going to feel is a few years from now when there won’t be any naturally spawned salmon left in the ocean,” said John McManus, executive director of the Golden State Salmon Association, which represents the salmon industry. the Peach.

When Lake Shasta was formed in the 1940s, it blocked access to cool mountain streams where fish traditionally spawned. To ensure their survival, the U.S. government is required to keep river temperatures below 56 degrees Fahrenheit (13 Celsius) in spawning habitat, as salmon eggs generally cannot withstand anything hotter. .

Hot water also begins to affect older fish. Scientists have seen adult fish die before they can lay their eggs.

“An extreme set of cascading weather events is pushing us into this crisis situation,” said Jordan Traverso, spokesperson for the California Department of Wildlife and Fish.

The West is grappling with a historic drought and recent heat waves made worse by climate change, straining the waterways and reservoirs that support millions of people and wildlife.

As a result, the state transports millions of hatchery-raised salmon to the ocean each year, avoiding the perilous journey downstream. State and federal hatcheries are taking other extraordinary steps to preserve depleted salmon stocks, such as maintaining a gene bank to prevent inbreeding in hatcheries and releasing them at critical life stages, when they can recognize and return to the water where they were born.

Fishermen and environmental groups accuse water agencies of diverting too much water too soon to farms, which could lead to serious salmon die-offs and bring the species closer to extinction.

“We know climate change is going to make years like this more common, and what agencies should be doing is dealing with the worst-case scenario,” said Sam Mace, director of Save Our Wild Salmon, a coalition who works to restore wild salmon and rainbow trout in the Pacific Northwest.

“We need real changes in the way rivers are managed if they are to survive,” she added.

On the Klamath River near the Oregon state line, California wildlife officials decided not to release more than a million young chinook salmon into the wild and instead drove them to hatcheries that could house them until river conditions improve.

Much depends on this class of salmon, as it could be the first to return to the river if plans to remove four of the six dams on the Klamath and restore fish access to the upper river go as planned.

Across the West, officials are grappling with similar concerns about fish populations.

In Idaho, officials recognized that endangered sockeye salmon wouldn’t make their upstream migration through hundreds of miles of warm water to their spawning habitat, so they flooded the Snake River with fresh water, then trapped and transported the fish to hatcheries.

And environmentalists went to court this month in Portland, Oregon, to try to force dam operators on the Snake and Columbia Rivers to release more water at dams blocking migrating salmon, arguing that the effects of the climate change and a recent heat wave further threatened fish. already on the brink of extinction.

Low water levels also affect recreational fishing. Officials in Wyoming, Colorado, Montana and California are asking anglers to fish during the cooler times of the day to minimize the impact on fish stressed by low oxygen levels in warm water .

Scientists say the salmon population in California has historically rebounded after a drought because they evolved to tolerate the Mediterranean-like climate and benefited from rainy, humid years. But a prolonged drought could lead to the extinction of some salmon runs.

“We’re at the point where I’m not sure drought is an appropriate term to describe what’s going on,” said Andrew Rypel, a fish ecologist at the University of California, Davis. He said the West is transitioning to an increasingly water-scarce environment.

Hudson, the fisherman, said he used to spend days at sea when the salmon season was longer and he could catch 100 fish a day.

This year, he said he was lucky to catch 80 to sell at the market.

“Retiring would be the smartest thing to do, but I can’t bring myself to do that because these fish have been so good to us all these years,” Hudson said. “I can not live without it.”