Largemouth Bass Virus detected for the first time in California, found in Nevada County lake

Largemouth Bass Virus has been detected for the first time in California, the California Department of Fish and Wildlife said Thursday.

The agency said that the virus, which is highly pathogenic, was detected in bluegill and largemouth bass in Lake of the Pines in Nevada County. The discovery was made after roughly 220 fish died in September in the lake.

The virus was confirmed by necropsies, CDFW said, and the source of the infection remains unknown.

The virus does not impact warm-blooded animals, including human. It can be transmitted into waters through infected baitfish, contaminated equipment, or by introducing infected carrier species, according to CDFW.

The virus was initially documented in Florida in the 1990s, and has since spread across the country. CDFW said it is difficult to eradicate the virus from a largemouth bass population once it is present. 

While the illness only affects largemouth bass, it can be carried by other fish species and cause disease in them. Infected fish exhibit a variety of symptoms, including bulging eyes, erratic swimming patterns, darkened skin and skin sores. 

There is no medication to treat the disease. Anglers are urged to take extra caution while handling freshly caught fish, and thorough cleaning of equipment is advised.

CDFW said it is investigating if the virus is present anywhere else in the state.