Bacterial Outbreak Forces Euthanization of Fish at Three Southern California Hatcheries

Three California Department of Fish and Wildlife (CDFW) fish hatchery facilities in the eastern Sierra and Southern California have been battling a bacterial outbreak that has affected 3.2 million fish. This week, after consultation with fish pathology experts and exhausting all avenues of treatment, CDFW announced that the fish, which are all trout, at the affected facilities must be euthanized in order to stop the spread of the outbreak.

The affected facilities – Mojave River Hatchery, Black Rock Hatchery and Fish Springs Hatchery – usually provide fish for stocking waterways in CDFW’s South Coast Region and Inland Deserts Region. The euthanization of all the fish at these facilities will have a profound effect on CDFW’s ability to stock fish for anglers in those regions in the near future.

“Euthanizing our hatchery stocks was not a decision we came to lightly, but it had to be done,” said Jay Rowan environmental program manager for CDFW hatcheries. “This bacterium is resistant to all the treatment options we have available for fish. The fish losses were getting worse despite our treatments. The best option we have available that will get us back to planting fish from these hatcheries in the shortest timeline is to clear the raceways, thoroughly disinfect the facilities, and start over.”

CDFW has had the three facilities under quarantine for more than a month, while pathologists and hatchery staff treated the affected fish and researched potential options. The outbreak of Lactococcus garvieae, which is similar to streptococcus, has been reported in cattle and poultry farms as well as fresh and salt water fish and shellfish hatcheries around the world, but had never before been detected in fish in California. Research of treatment options employed at trout farms in Europe and other parts of the world show there is almost no chance for successfully eliminating the bacteria from a facility without depopulation and disinfection.

Fish that are infected with Lactococcus garvieae can show symptoms including bulging eyes, lethargic or erratic swimming and increased mortality, or be asymptomatic and show no signs of infection depending on a several factors including water temperature and stress. Fish-to-human transmission of this bacteria is rare and unlikely but there are several documented instances associated with immunocompromised people consuming infected raw fish and unpasteurized milk products.

Hot Creek Hatchery in the eastern Sierra has tested negative for the bacteria and is still planting eight waters in Inyo and Mono counties. CDFW is in the process of developing a modified stocking plan to reallocate fish from central and northern California hatcheries to a small number of high angler use, easily accessible waters in geographically distinct parts of the eastern Sierra and Southern California.

For real-time updates, California anglers can refer to CDFW’s Fish Planting Schedule. This schedule is updated directly by CDFW hatchery staff. Although it contains current information, all fish plants are subject to change depending on road, water, weather and operational conditions.

For additional information, please see CDFW’s frequently asked questions about the L. garvieae outbreak. Also, members of the public can email questions to hatcherybacteriainfo@wildlife.ca.gov.

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Media Contacts:
Jay Rowan, CDFW Hatchery Program, (916) 212-3164
Harry Morse, CDFW Communications, (208) 220-1169

CDFW fish hatchery planting trucks

CDFW’s Salmon Evacuation Decision Pays Exceptional Dividends

In February 2017, damage to the Oroville Dam’s spillways prompted the evacuation of more than 180,000 people living downstream along the Feather River. The raging muddy waters also triggered an emergency decision to relocate millions of young salmon from the Feather River Hatchery to the Thermalito Annex Hatchery to be raised and held until river water conditions improved. Most, if not all, of the young salmon would have otherwise died when mud from the raging river overwhelmed the hatchery waters.

About 2 million spring run Chinook and 5 million fall run Chinook were evacuated during the two-day flood event. Those fish survived and were later released to the wild – helping fuel a record class salmon harvest in the ocean two years later.

Last year, most of the rescued salmon had matured in the ocean and were ready for their migration home to the Feather River. Their survival helped power strong ocean fisheries with one of the largest commercial catches in decades. According to data collected by the California Department of Fish and Wildlife (CDFW), approximately 272,000 salmon were harvested in the commercial fishery along with a catch of nearly 88,500 in the recreational ocean fishery, while returns to the Feather River basin exceeded 70,000 in 2019.

Ocean fishing activities were an economic stimulus for local communities and industries along the coast and inland. Commercial trollers landed 2.6 million pounds of salmon valued at more than $17.2 million, which was the highest level of harvest since 2013. The Feather River Hatchery was estimated to have contributed one quarter of all commercially harvested salmon and one third of the recreational ocean harvest.

“The return of the salmon released from Feather River Hatchery after the flood event was exceptional,” said Kevin Shaffer, CDFW Acting Chief of the Wildlife Branch. “At several points in the crisis, the majority (if not all) of the young salmon could have been lost. If not for the hard work, ingenuity and dedication of the hatchery employees and staff we could have ended up with nothing.”

The effort to save the young salmon began on Feb. 9 and 10, 2017. More than 60 people from CDFW, the California Department of Water Resources, the National Oceanic and Atmospheric Administration (NOAA) Fisheries and other agencies worked night and day to successfully transfer more than 5 million Chinook salmon to the Thermalito Annex hatchery facility nine miles away. Fisheries and engineering staff also constructed an emergency filtration system for the remaining salmon and steelhead at the Oroville facility, saving an estimated 1.5 million fall Chinook salmon fry that were too small to move and 1.6 million steelhead eggs which lead to a returning year class of 1,874 steelhead in 2018-19.

On March 20, 2017, the first salmon to be released after the evacuation were 1 million state and federally listed threatened spring-run Chinook salmon. They were released successfully into the Feather River. In all, a total of 2 million spring-run Chinook and 5 million fall-run Chinook were released.

Their work did not go unnoticed. Team members received a letter of appreciation from then-Lt. Governor Gavin Newsom, and were later presented with the CDFW Director’s “Team Award” for their ingenuity and dedicated work to save the salmon and steelhead eggs.

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Media Contacts:
Harry Morse, CDFW Communications, (208) 220-1169
Jay Rowan, CDFW North Coast Region, (916) 358-2883

 

Feather River Hatchery Closed Until Further Notice

Due to recent flooding from the Feather River, the Feather River Hatchery in Oroville will remain closed to the public until further notice.

The hatchery’s infrastructure and public viewing areas were damaged by high flood waters, silt and debris, making it unsafe for the public to be on the grounds or access the river via hatchery property.

“Our staff is focused on keeping the hatchery salmon and steelhead alive, and facility cleanup efforts won’t be completed for some time,” said Anna Kastner, Feather River Hatchery Manager. “We appreciate the public’s patience and support of our efforts to preserve these critical stocks under unusual and challenging circumstances. We’ll be very happy when all operations are back to normal.”

On Feb. 9 and 10, more than 60 people from the California Department of Fish and Wildlife, the National Oceanic and Atmospheric Administration (NOAA) Fisheries and other agencies successfully transferred more than five million Chinook salmon to an annex hatchery nine miles away. Fisheries staff also constructed an emergency filtration system for the remaining salmon and steelhead at the Oroville facility.

To date, losses at the hatchery have been minimal.

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Media Contacts:
Anna Kastner, CDFW Feather River Fish Hatchery, (530) 538-2222

Andrew Hughan, CDFW Communications, (916) 201-2958