In a stopgap measure to help struggling spring and winter chinook salmon spawn in the face of rising water temperatures and falling water levels due to climate change, wildlife officials in the States and federal government in Northern California have begun trucking adult fish to colder waters.
Spring and winter salmon are genetically different, with seasonal tags marking when adult fish travel from the Pacific Ocean to the Sacramento River to spawn.
Spring Chinooks, listed as threatened under the Endangered Species Act, are moved from traps at the base of Keswick Dam to Clear Creek in the Sacramento River.
About 300 specimens of the winter salmon, listed as endangered since 1994, are moved from a government-run hatchery to the waters above Eagle Canyon Dam on the North Fork of Battle Creek, east of Redding. The relocation, which began with a single fish, marks the first time in more than 110 years that winter run salmon have occupied these waters.
“It’s just a beautiful, cool, shady habitat for them,” said California Department of Fish and Wildlife spokesman Peter Tira. “Although they cannot physically access it because of the barriers, their offspring will be able to simply descend the waterfalls and may migrate to the ocean.”
The efforts, which began last month, are short-term emergency measures, particularly for winter run salmon, Tira said.
“It’s the third year of drought, and these fish have a three-year life cycle, basically,” he said. “And we’ve had two years of bad production, so we can’t afford to have another year of bad production.”
Since 1997, the U.S. Fish and Wildlife Service has operated the Livingston Stone National Hatchery to produce winter chinook, and production is expected to be increased in another attempt to bolster the population.
Efforts are temporary until a permanent solution allowing fish to reach areas above Shasta Lake can be found. One proposal would see the fish trucked directly to the McCloud River, above Shasta Dam, to spawn. Their offspring would then be trapped and trucked up the Sacramento River to begin their journey to the Pacific.
Construction of dams such as nearby Eagle Canyon and Shasta, as well as Pacific Gas & Electric facilities, have prevented salmon from reaching their natural spawning habitats fed by colder waters.
Winter run salmon, for example, have been unable to reach areas like the McCloud River above Shasta Dam, which are fed by cold springs.
Instead, the fish were forced to lay their eggs at the base of Shasta Lake in the shallow Sacramento River. And the drought and rising temperatures have heated the water fed from Lake Shasta to the river.
High temperatures are deadly to winter run salmon eggs; last year, according to state biologists, less than 3% of eggs hatched.
With warming waters taking a toll on Chinook salmon spawning, government plans to reintroduce the fish to cooler habitats have raised concerns among members of the Winnemem Wintu tribe, whose ancestors were displaced by the Shasta Dam and for whom salmon is at the heart of cultural life and spiritual traditions.
Instead of releasing hatchery-raised fish, the tribe wants to use salmon that once lived in the Sacramento River but were transplanted to New Zealand more than a century ago.
“There is no one else who is more supportive of bringing fish back to this river than the Winnemem,” Caleen Sisk, chief and spiritual leader of the Winnemem Wintu Tribe, told The Times recently. “But if you bring in hatchery fish, we will object.”
Rather than transporting the salmon in trucks, the tribal leaders want to develop a way for the fish to move naturally upstream, past the dam, to Lake Shasta.
Years ago, the tribe came up with a proposal to reintroduce a swimming lane with a holding pond, pumps and a channeling system that would allow fish to swim upstream, exiting through a floating structure in the tank. .