Salmon surge into new Nimbus Fish Hatchery ladder on American River

Fall-run Chinook salmon are now moving into the rock-lined channel at the entrance to the new weir fish ladder at Nimbus Fish Hatchery on the American River.
Fall-run Chinook salmon are now moving into the rock-lined channel at the entrance to the new weir fish ladder at Nimbus Fish Hatchery on the American River.

RANCHO CORDOVA — As hundreds of Chinook salmon congregated in the rock-lined channel at the entrance to the new Nimbus Fish Hatchery ladder, the Bureau of Reclamation and California Department of Fish and Wildlife on Nov. 2 held a short ribbon cutting ceremony marking the completion of the hatchery’s new Fish Passage Project.

Before the ceremony, hatchery staff took more than 700 salmon into the facility in just 20 minutes, according to Gary Novak, hatchery manager. The hatchery has trapped a total of 1,800 salmon and has taken 650,000 green eggs in two spawning sessions to date.

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State and federal officials said the modernized ladder and flume fishway will help fall Chinook salmon and Central Valley steelhead returning to the hatchery.

The 1,900-foot-long passageway consists of a rock-lined channel, weir fish ladder, and concrete flume. The new project features a visitor plaza with underwater public viewing windows. Construction began in spring 2020 and was completed in October.

Speakers at the event included David Palumbo, deputy commissioner, Bureau of Reclamation; Ernest Conant, regional director, Bureau of Reclamation; Chuck Bonham, director, California Department of Fish and Wildlife; and Drew Lessard, Central California area office manager, Bureau of Reclamation.

The officials said the project, which took 10 years of planning and construction to complete, creates “a more reliable and safer system” for collecting adult fall-run Chinook salmon and Central Valley steelhead trout at the Nimbus Hatchery.

“Not only will this new and improved fish ladder greatly improve our hatchery operations and efficiencies at Nimbus, we’ve moved the ladder entrance to lessen the disturbance for those salmon and steelhead spawning naturally in the river,” CDFW Director Charlton H. Bonham said. “We’re proud to be part of a project that simultaneously benefits both our hatchery operations and wild-spawned fish and improves the visitor experience along the river and ladder for our Sacramento-area constituents who love to tour this facility, even though it has been closed recently due to COVID-19.”

Bonham also announced CDFW’s Nimbus staff have been tasked with increasing hatchery production to 4.5 million salmon smolts this year by producing 500,000 additional fish to “combat effects of the drought.”

“Chinook salmon returns to the American River declined significantly during California’s last drought,” Jason Julienne, supervisor for CDFW’s North Central Region fish hatcheries, said. “We’re using those observations and that experience to get ahead of any population declines this time around by increasing production to help sustain this important salmon run.”

However, California Sportfishing Protection Alliance fishery biologist Tom Cannon said in his California Fisheries blog that “American River fall-run salmon escapement has dropped after recent drought years and would be expected to fall again in 2022 and 2023 as a consequence of the 2020-2021 drought period.”

“Until river and Bay dry-year flow conditions are improved, a 10% increase in hatchery smolt releases will unlikely improve escapement to recent historical levels,” he said.

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Cannon said he likes the new ladder because it gets rid of the weir that they had to take in and out each year by reducing Nimbus Dam releases. “It also opens the river up to Nimbus Dam,” he said. Information: calsport.org

The Nimbus Fish Hatchery’s facilities are still closed to the public due to COVID-19, but the lower portion of the fish ladder is open to public access.

Additional virtual opportunities and resources are available at https://wildlife.ca.gov/Learning

Sacramento River late fall Chinooks: While fall-run salmon are now in spawning mode, the Sacramento metropolitan area is producing bright late fall kings. Rob Reimers of Rustic Rob’s Guide Service and Jimmy Downs had a great day on Nov. 5 when they landed three salmon weighing 18, 16 and 8 pounds while trolling with Brad’s Cut Plugs behind flashers from Discovery Park to Garcia Bend. Information: (530) 632-0051.

Contact Record Correspondent Dan Bacher at danielbacher53@gmail.com.

This article originally appeared on The Record: Salmon surge into new Nimbus Fish Hatchery ladder on American River