MORE TROUT INFECTIONS AT EASTERN SIERRA HATCHERY

Hot Creek Hatchery in Mono County has suffered a second outbreak of Lactococcus garvieae, a condition similar to strep throat. California Department of Fish and Wildlife announced about 170,000 rainbow and brown trout, 15 percent of the hatchery’s stock, were infected and would be humanely

euthanized. (CALIFORNIA DEPARTMENT OF FISH AND WILDLIFE)

HATCHERY ENDURES SECOND BACTERIAL OUTBREAK 15 PERCENT OF MONO COUNTY FACILITIES’ RAINBOWS, BROWNS INFECTED

Just like humans have been fighting the spread of COVID-19, infections have wreaked havoc on trout being raised at Hot Creek Hatchery in Mono County.

For the second time this year, a bacterial outbreak has stricken the state-run hatchery’s fish. Fortunately for local anglers, in both instances the outbreaks have been caught early, though thousands of trout have been infected with Lactococcus garvieae, a condition comparable to streptococcus or strep throat.

Per a California Department of Fish and Wildlife press release, 15 percent of Hot Creek Hatchery’s trout have been infected, 118,000 rainbow trout and 52,000 browns. Of the latter species, 2,000 were broodstock fish that weighed 2 to 3 pounds apiece.

CDFW announced it would quarantine the hatchery and suspend its trout planting program. The infected fish would also be “humanely euthanized,” and facility managers plan to vaccinate all the fish stocks that aren’t infected.

“The encouraging news is that we caught the outbreak early as part of our routine testing and only a portion of the hatchery’s trout has been infected,” said Jay Rowan, CDFW’s statewide hatchery program manager. “We now have proven and effective vaccines to protect uninfected fish – vaccines developed recently in a partnership between UC Davis and CDFW. We’re in the process of vaccinating the hatchery’s healthy fish populations. Unfortunately, we don’t have a cure or treatment for infected fish at this time.”

Hot Creek is an important Eastern Sierra hatchery for rearing and stocking trout for some of the region’s most popular fisheries, including Crowley Lake and stretches of the Owens River.

“CDFW expects low to moderate impacts to waters stocked by the Hot Creek Trout Hatchery in 2022,” the press release stated. “Nearly a million fish have tested negative and will undergo vaccination, either through a bath immersion process for smaller, juvenile fish or injection into larger fish. These healthy populations include rainbow trout broodstock, brown trout broodstock, rainbow and brown trout of various sizes, and juvenile Lahontan cutthroat trout. Once vaccinated, the fish will be safe to plant and safe for anglers to consume.”

Similar outbreaks occurred in other Eastern Sierra and Southern California hatcheries in 2020, resulting in about 3.2 million fish euthanized, but those facilities are operational again, and two are back to stocking trout for recreational fisheries. CS