Nearly 350,000 Fish Will Be Euthanized After Bacteria Outbreak At Two Hatcheries

California State Fish and Wildlife officials confirm roughly 350,000 rainbow trout will be euthanized after bacteria outbreaks at two hatcheries in the Eastern Sierra that were discovered in April.

Those facilities usually provide fish for stocking waterways in the Inland Deserts Region, which includes Riverside and San Bernardino counties.

Hatchery Program Manager Ken Kundargi says they're still trying to figure out the source of the naturally occurring bacteria, Lactococcus petauri.

“One hypothesis, which is unproven ... we can't determine the source of it ... but it's quite possible that it was transported by birds that are migrating up the West Coast, and the virus has been cultured and detected in bird droppings in the vicinity of the hatcheries.”

Kundargi says the department is working to buy fish from an outside vendor, to make up for the shortfall, while other state hatcheries are stocking fish in "priority waters."

Infected fish may show symptoms — such as bulging eyes or erratic swimming — or none at all.

Officials say fish-to-human transmission of the bacteria is "rare and unlikely" but recommend cooking fish to an internal temperature of 145 degrees.

The same two hatcheries had a similar outbreak in 2020 that resulted in the euthanizing of about 3.2 million fish to stop contamination.

Although it has already wreaked havoc at the multiple hatcheries, the pathogen is relatively new to the state. The first time the bacterium was found was in April 2020. The CDFW says that the new introduction, along with the bacteria’s resistance to USDA approved antibiotics, complicates the fishes’ medical treatment.