SAN FRANCISCO — Baby salmon are dying by the thousands in one California river, and an entire run of endangered salmon could be wiped out in another. Fishermen who make their living off adult salmon, once they enter the Pacific Ocean, are sounding the alarm as blistering heat waves and extended drought in the U.S. West raise water temperatures and imperil fish from Idaho to California.
Hundreds of thousands of young salmon are dying in Northern California’s Klamath River as low water levels brought about by drought allow a parasite to thrive, devastating a Native American tribe whose diet and traditions are tied to the fish. And wildlife officials said the Sacramento River is facing a “near-complete loss” of young Chinook salmon due to abnormally warm water.
A crash in one year’s class of young salmon can have lasting effects on the total population and shorten or stop the fishing season, a growing concern as climate change continues to make the West hotter and drier. That could be devastating to the commercial salmon fishing industry, which in California alone is worth $1.4 billion.
The plummeting catch already has led to skyrocketing retail prices for salmon, hurting customers who say they can no longer afford the $35 per pound of fish, said Mike Hudson, who has spent the last 25 years catching and selling salmon at farmers markets in Berkeley.
Hudson said he has considered retiring and selling his boat because “it’s going to get worse from here.”
Winter-run chinook salmon are born in the Sacramento River, traverse 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-run chinook that survives almost entirely due to hatchery breeding programs, the winter run is still largely reared in the wild.
Federal fisheries officials predicted in May that more than 80 percent of baby salmon could die because of warmer water in the Sacramento River. Now, state wildlife officials say that number could be higher amid a rapidly depleting pool of cool water in Lake Shasta. California’s largest reservoir is filled to only about 35 percent capacity, federal water managers said this week.
“The pain we’re going to feel is a few years from now, when there will be no naturally spawned salmon out in the ocean,” said John McManus, executive director of the Golden State Salmon Association, which represents the fishing industry.
When Lake Shasta was formed in the 1940s, it blocked access to the cool mountain streams where fish traditionally spawned. To ensure their survival, the U.S. government is required to maintain river temperatures below 56 degrees in spawning habitat because salmon eggs generally can’t withstand anything warmer.
The warm water is starting to affect older fish, too. Scientists have seen some adult fish dying before they can lay their eggs.
“An extreme set of cascading climate events is pushing us into this crisis situation,” said Jordan Traverso, a spokeswoman for the California Department of Wildlife and Fish.
The West has been grappling with a historic drought and recent heat waves worsened by climate change, stressing waterways and reservoirs that sustain millions of people and wildlife.
As a result, the state has been trucking millions of salmon raised at hatcheries to the ocean each year, bypassing the perilous downstream journey. State and federal hatcheries take other extraordinary measures to preserve the decimated salmon stocks, such as maintaining a genetic bank to prevent inbreeding at 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 blame water agencies for diverting too much water too soon to farms, which could lead to severe salmon die-off and drive the species closer to extinction.