Chinooks Swim Again in the North Yuba After 80 Years

SIERRA COUNTY — Last week, the California Department of Fish and Wildlife (CDFW) announced that it captured juvenile Chinook salmon using its Rotary Screw Trap located at Rocky Rest Campground. The news comes after eggs were implanted on a riverbed near Downieville in October as part of a pilot study on reintroducing the fish to the North Yuba River.

Many Downieville residents are already familiar with CDFW’s efforts in the region, which began with the installation of two rotary screw traps in North Yuba for the 2023-2024 season. Because those traps were successfully operated, despite not actively “fishing” at the time, CDFW moved ahead with the next step in the program: planting the salmon.

Fertilized salmon eggs were provided by CDFW’s Feather River Hatchery in Oroville. CDFW says fishery scientists “created dozens of man-made salmon redds, or nests, using a hydraulic injection system to clear the intended nests of silt.” Eggs were then deposited up to 1.5 feet deep into the gravel, mimicking natural adult salmon spawning.

The first juveniles were seen in the Rotary Screw Trap on February 11th. Once captured, the fish are trucked downstream below the Englebright Dam, where they are released to continue their journey to the ocean. When they return in the fall, they must be trucked from below the Englebright Dam to above the New Bullards Bar Dam, neither passable by salmon. Should spring-run Chinook salmon reintroduction remain a priority for CDFW, the fish must be transported annually.

On the program’s future, Fisheries Environmental Program Manager for CDFW’s North Central Region Colin Purdy says, “If we can develop this pilot effort into a full reintroduction program, we would be able to more than double the amount of available salmon habitat in the Yuba River watershed. And that’s a huge win for spring-run Chinook salmon.” Salmon have been prevented from spawning in the river near Downieville since the 1941 construction of the Englebright Dam. CDFW describes North Yuba waters as “perhaps the most high-quality and climate-resistant habitat in the Central Valley for this species.”

Purdy also says that the pilot study is a prime opportunity to learn how the salmon will react to the North Yuba River. Scientists will “look at how long it takes for eggs to hatch and turn into yolk sac fry, how do they rear, how fast do they grow, when and where do they rear as juvenile salmon,” says Purdy. The work is aided by a form of DNA tagging, which allows scientists to trace the heritage of any given salmon back to eggs from the Feather River Hatchery.

The Yuba Salmon Study, the umbrella under which this pilot study is being conducted, is part of a greater strategy for preserving salmon in the State of California, outlined by Governor Gavin Newsom in a 2024 document titled “California Salmon Strategy for a Hotter, Drier Future.” The document includes removing barriers like dams and modernizing infrastructure, including installing fish ladders, which are not feasible along the Yuba River. The height of the New Bullards Bar Dam makes fish ladders unrealistic, and both the Englebright and Bullards Bar Reservoirs are necessary for water supply and flood control.

The Chinook trucked below the Englebright Dam will spend two to four years in the ocean before returning to spawn. Though Newsom’s document specifies that the “first steps” should be taken to re-establish spring-run Chinook populations in the North Fork of the Yuba River by 2025 (a goal that can be marked complete), no pathway exists to maintain their natural spawning cycle without human intervention.