An estimated 200,000 to 300,000 fall-run Chinook salmon were killed early yesterday morning at the Feather River Fish Hatchery – Thermalito Facility due to a pump failure from a faulty wire. More than two million remaining salmon at the facility will be released over the next month as they reach an appropriate size.
Overnight on May 10, 2017, the primary pump supplying well water to the facility failed, drastically reducing the water supply to the hatchery raceways.
California Department of Fish and Wildlife (CDFW) staff first observed stressed fall-run Chinook salmon at 6:30 a.m. along with mortalities in the raceways due to low dissolved oxygen levels. Hatchery staff immediately started supplying supplemental oxygen to the raceways to keep fish alive. CDFW notified the California Department of Water Resources (DWR), which manages the wells, and DWR electricians made immediate repairs to restart the pump motor and resume the flow of water.
Early loss estimates suggest 200,000-300,000 fall-run perished in this event. A rapid response likely saved thousands if not millions more fall-run Chinook at the facility.
The fall-run were reared at the Thermalito Facility after they were evacuated from the main hatchery in February following erosion of the Oroville Dam gated flood control spillway.
More than two million fall-run Chinook at the Thermalito Facility will remain there until they reach an appropriate size for release to the Feather River. Releases begin this week and will continue over the next month. CDFW and DWR staff are developing additional redundancy measures to prevent future pump failures.
The Mojave River Hatchery near Victorville in San Bernardino County will be closed to the public as of May 1, to allow for maintenance and repairs of the raceways, buildings and equipment. The facility is expected to reopen in approximately three to four months when all repairs are complete.
All fish currently at the hatchery will be stocked by the end of April. During the temporary closure, the rainbow trout that would normally be hatched and raised at the Mojave River Hatchery will be instead be raised at the Fillmore Hatchery and stocked from there to Southern California waters.
“We understand that anglers are concerned about their favorite fishing spots being affected, but rest assured, we will continue to stock the 66 waters in six counties with trout just as we have done in the past,” said CDFW Senior Hatchery Supervisor Gary Williams. “The work being done will make our operations more efficient and result in better fish production for Southern California.”
Once the maintenance projects are complete, the hatchery will resume all operations and reopen to the public.
The California Department of Fish and Wildlife (CDFW) in cooperation with the National Oceanic and Atmospheric Administration (NOAA) National Marine Fisheries Service (NMFS) released one million state and federally listed threatened spring-run Chinook salmon into the Feather River on Monday, March 20.
These were the first fish to be released that were evacuated from the Feather River Hatchery in Oroville on Feb. 9, when the water became dangerously murky following the failure of the Oroville Dam spillway. The fish were moved to the Feather River/Thermalito Annex Hatchery and held there until conditions improved.
“Based on the weather forecast and current reservoir storage, we are anticipating high flows in the Feather River for some time,” said CDFW Senior Environmental Scientist Colin Purdy. “Releasing these fish now should allow them to imprint on Feather River water and move downstream before flows drop back down to normal levels.”
Central Valley spring-run Chinook are a state and federally listed species and their abundance has declined considerably during the recent drought. The Feather River Fish Hatchery plays a key role in the state’s efforts to propagate this unique run of Chinook salmon.
“Today’s fish release marks the success of federal and state agencies coordinating and managing valuable resources while ensuring public safety during a crisis situation,” said Howard Brown, NOAA Sacramento River Basin Branch Chief. “NOAA Fisheries remains deeply concerned with the damage of the Oroville spillways and is committed to reducing further threats to California communities and ecosystems.”
“This is another example of the extraordinary multi-agency effort to respond to this unfortunate incident,” said California Department of Water Resources Acting Director Bill Croyle. “We will continue to work closely to protect the Feather River and its fisheries.”
Of the fish that were evacuated, another million spring-run Chinook and three million fall-run Chinook remain at the Annex Hatchery. CDFW and NOAA fisheries staff will continuously evaluate the remaining salmon and begin planting them in northern California Rivers when the fish are mature enough.
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Media Contacts: Andrew Hughan, CDFW Communications, (916) 201-2958 Jim Milbury, NOAA Fisheries, (562) 980-4006
Following recent heavy rains, workers at the Nimbus and American River hatcheries labored around the clock to prevent massive debris loads from clogging the main water supply for below Nimbus Dam. Their intense efforts to clean intake structures and adjust water flows during battering winds and rains saved millions of eggs and young fish over the 11-day ordeal.
After a winter deluge from Jan. 7-18, the two hatcheries’ main water source experienced clogging that affected the water distribution system, putting more than 5.5 million trout and salmon eggs and 3 million young trout, steelhead and salmon in peril.
Both hatcheries are on a gravity water flow supply from the main intake screen at Nimbus Dam. There are no other filters until the water reaches each hatchery.
January storms swelled water levels at Folsom and Nimbus dams to the highest points since the El Niño floods of 1997-1998. The high flows resulted in a release of up to 60,000 cubic feet of water per second (cfs) from Nimbus Dam, while the normal rate is around 6,000-10,000 cfs. This huge water flow swept up debris that had collected above water line during the extensive drought. The debris clogged, overwhelmed and then incapacitated the automatic cleaning screen at the intake, compromising water flow to both hatcheries.
In a joint cooperative effort and at the height of the crisis, technicians from the Bureau of Reclamation devised a simple but effective way to quickly remove the debris clogging the main intake screen. They also bypassed systems that limited the time between cleaning cycles on the machinery, thereby allowing CDFW personnel to monitor the process 24 hours a day and keep water flowing to the hatcheries.
“It was a tense situation that called on our staff to work double shifts cleaning and operating the main intake structure screen and unclogging egg incubation jars inside each hatchery,” said Nimbus Hatchery Manager Paula Hoover. “They were working as fast as they could, 24/7, to save the fish.”
At American River Hatchery, the recent crisis threatened 1.4 million trout eggs in various stages of development, along with 1.7 million young trout. The fish and eggs were in danger of suffocation as the debris clog caused reduced oxygen levels and reduced the flow of water as much as 50 percent. Further complicating operations, the drum filter for the hatchery building was overwhelmed by the increased sediment, prompting workers to create a bypass to keep water flowing to the building.
The hatchery raises more than 2.5 million trout annually for planting in lakes, rivers and streams in 15 counties throughout northern and central California. More than a quarter of a million anglers utilize these waters for recreational fishing.
None of the Golden Trout rescued from the Volcanic Wilderness Area due to drought conditions were affected because they are housed in aquaculture systems that can be switched to 100 percent recirculation as needed. These Golden Trout will be kept at the hatchery until conditions in their natural habitat improve and they can be released back to the wild, likely in the late spring or early summer of this year.
At Nimbus Hatchery, 450,000 steelhead and 4.5 million salmon in various stages of development faced the same dire situation. Preparing for the worst, staff had emergency equipment ready to perform on-site releases of more than 250,000 year-old steelhead into the raging American River if conditions at the hatchery deteriorated further.
“The recreational and economic impact from potential loss of trout, salmon and steelhead from these two hatcheries would be substantial,” said North Central Region Fisheries Program Manager Kevin Thomas. “As usual, dedicated CDFW hatchery staff demonstrated exceptional care and effort, helping millions of fish survive to provide recreational, commercial and tribal fishing opportunities for California and the businesses they support.”
The salmon ladder at Nimbus Hatchery in Rancho Cordova will open Wednesday, Nov. 2, signaling the start of the spawning season on the American River. California Department of Fish and Wildlife (CDFW) hatchery workers will open the ladder gates at 10:45 a.m. Hatchery employees may take more than a half-million eggs during the first week of operation alone in an effort to ensure the successful spawning of the returning fall run Chinook salmon.
There are eight state-run salmon and steelhead hatcheries, all of which will participate in the salmon spawning effort. Over the next two months, the three major state-run hatcheries in the Central Valley – the Nimbus Hatchery in Sacramento County, the Feather River Hatchery in Butte County and the Mokelumne River Hatchery in San Joaquin County – will take approximately 24 million eggs in order to produce Chinook salmon for release next spring.
Each hatchery has a viewing area where visitors can watch the spawning process. The visitors’ center at Nimbus Hatchery also includes a playground with replicas of giant salmon that are enjoyed by young and old alike. For more information about spawning schedules and educational opportunities at each hatchery, please visit the CDFW website at www.wildlife.ca.gov/fishing/hatcheries.
Together, state and federally operated hatcheries raise 40 million juvenile salmon for release into California waters each year. Once the young salmon reach 2 to 4 inches in length, one-quarter of the stock are marked and implanted with coded wire tags prior to release. CDFW biologists use the information from the tags to chart survival, catch and return rates. These massive spawning and tracking efforts were put in place over the last 50 years to offset fish losses caused by dams that block salmon from historic spawning habitat.