FRESNO, Calif. (CN) – In California’s Central Valley, dusty dry riverbeds fill with water that for decades has been diverted for farmers and cities. Hatchery-reared salmon – bred with taxpayer funds – are being reintroduced in hopes of rebooting ancient populations that disappeared in the 1940s, casualties of California’s ceaseless search for new water sources. The San Joaquin River, the state’s second largest, is primed for its comeback.
After the Sacramento River, the San Joaquin is California’s most important river. It provides some of the state’s largest agricultural operations with water as it stretches north from Fresno before finally emptying into the Sacramento-San Joaquin River Delta – the source of drinking water for an estimated 25 million Californians.
The process of damming, diverting and plumbing the 366-mile river for irrigation and urban water use leaves main portions of the river dry during parts of the year. Following the opening of Friant Dam in 1942, entrepreneurs gobbled up the river’s fertile wetlands and replaced them with crops and gravel mining operations.
The dam was a boon to the already prospering agricultural region. But as water-intensive crops like almonds and pistachios went in, the native Chinook salmon disappeared.
Thanks to an 18-year federal lawsuit brought by the Natural Resources Defense Council, the state and federal government plan to spend over a billion dollars to restore flows, wetlands and fish to the San Joaquin River system. A settlement reached in 2006 set goals of restoring native fish populations to “good condition” without overtly damaging water suppliers’ take of the river.
According to the latest estimates, the project will cost more than $1.5 billion and won’t be completed until after 2030.
Biologists and experts affiliated with the restoration program say the process of reviving an extinguished species on such a large river is likely unprecedented.
“Taking a river system so heavily altered and trying to renovate it is truly unique,” said Paul Adelizi, environmental scientist with the California Department of Fish and Game.
Adelizi and a team of researchers oversee a small fish hatchery just below the Friant Dam outside of Fresno, where spring-run Chinook salmon and trout are reared for release into the San Joaquin. Some of the fish and game employees live on-site in trailers or in temporary housing, on standby in case issues arise in one of the many circular salmon holding pens.
With river flows and temperatures cooperating on a warm May morning, the hatchery team executed its most important salmon release yet. They carefully herded dozens of adult spring-run Chinook salmon from holding pens into delivery tanks, finally releasing the fish downstream after years of captivity.
The fish are the first adult salmon born and raised on the river to have the chance to spawn naturally in nearly a century, researchers estimate.
“It’s a huge milestone,” said Don Portz, who oversees the fish restoration program for the U.S. Bureau of Reclamation. “But the ultimate milestone will be when the babies come back to the river.”
The salmon will roam the stretch of river below the hatchery throughout the summer until they are ready to spawn and lay eggs. The hatchery fish will have to survive fluctuating river flows and temperatures, as well as steer clear of predators and poachers.
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