Saving salmon: Chinook return to California’s far north — with a lot of human help
Chinook salmon haven’t spawned in the McCloud River for more than 80 years. But last summer, thousands of juveniles were born in the waters of this remote tributary, miles upstream of Shasta Dam.
The young Chinook salmon — some now finger-sized smolts in mid-migration toward the Pacific Ocean — are part of a state and federal experiment that could help make the McCloud a salmon river once again.
Winter-run Chinook were federally listed as endangered in 1994, but recent years have been especially hard for the fish. Facing severe drought and warm river conditions, most winter-run salmon born naturally in the Sacramento River have perished over the past three years.
So restoring Chinook to the McCloud has become an urgent priority for state and federal officials. In the first year of a drought-response project, about 40,000 salmon eggs were brought back to the McCloud, a picturesque river in the wilderness of the Cascade mountains.
Iconic in Northern California, Chinook salmon are critical pieces of the region’s environment. They are consumed by sea lions, orcas and bears, and they still support a commercial fishing industry. Chinook remain vital to the culture and traditional foods of Native Americans, including the Winnemem Wintu Tribe, whose historical salmon fishing grounds included the McCloud River.
Conservation experts say the McCloud’s cold, clean water holds great promise as a potential Chinook refuge — and perhaps even a future stronghold for the species. Restoring salmon there is considered critical to the species’ survival, since they now spawn only in low-lying parts of the Central Valley near Redding and Red Bluff, where it’s often too hot and dry for most newborn fish to survive.
“We probably won’t be able to maintain winter-run chinook on the valley floor forever,” said Matt Johnson, a senior environmental scientist with the California Department of Fish and Wildlife.
Johnson spent much of the past five months camped beside the incubation site on the lower McCloud River, guarding the eggs and emerging fry and overseeing the experiment, which is a collaboration between his agency, the National Marine Fisheries Service, the U.S. Fish and Wildlife Service and the Winnemem Wintu Tribe.
So far, the project, biologists say, has gone well. About 90% of the eggs hatched, and the young fish have reportedly thrived in the McCloud, growing faster than hatchery fish.
Recent rain storms have boosted river flows, which may increase the odds that salmon will reach the ocean this year, escaping the dangerous water pumps and predators of the Delta.
The project is the first step in a long-term plan that may involve capturing adult winter-run Chinook in the lower Sacramento and transporting them to the McCloud to spawn. It’s a difficult and risky venture for the fish but it may be the best shot the species has at survival.
“The winter run is headed for extinction, no question, if we don’t develop an artificial system for keeping it going,” said Peter Moyle, a fish biologist at UC Davis who has studied Central Valley fish since the 1970s. He co-authored a report warning that many of California’s native salmon and trout are likely to vanish this century as the environment warms.
A genetically unique run of salmon, winter-run Chinook once spawned in the McCloud in great numbers, along with other seasonal runs of the fish.
Even though the Central Valley’s river system, which includes the McCloud River, marks the southern limit of the Chinook’s range, it was once their stronghold. Between 1 and 2 million fish, some weighing 50 pounds or more, spawned in the tributaries of the Sacramento and San Joaquin rivers each year before the Gold Rush.
The fish have dwindled to a fraction of their historic abundance. Spawning numbers of winter-run Chinook dropped to fewer than 200 in the early 1990s. They’ve rebounded, but their future remains in doubt.
The McCloud — a state-designated wild and scenic river — used to offer prime habitat, with deep gravel beds for egg-laying and year-round flows of clean, cold water from Mount Shasta. Construction of Shasta Dam in the 1940s – and Keswick Dam shortly after – changed all this by locking ocean-run salmon out of some 500 miles of productive high-elevation habitat.