Submitted by Mari Erin Roth
The California Department of Fish and Wildlife (CDFW) announced yesterday that it has been working with local authorities in response to fish mortalities at Lake Davis. In early June, Brown Bullhead, a species of catfish, were observed floating and/or washed up onshore at Lake Davis. A small number of dead or dying Largemouth Bass and Pumpkinseed were observed as well.
When asked what she thought about the fish situation in Lake Davis, Jeanne Graham of J&J Grizzly Store said, “It’s just the cats,” referring to the catfish in the lake. For a few weeks, diseased Brown Bullhead Catfish washed up on the shore of Lake Davis. They are still there according to Jeanne, but the birds and animals are eating them.
The lake was 97 percent full when the dead fish started showing up on the shoreline. The lake has since lowered to 95 percent in the past couple of weeks, which has put a few feet of shoreline between the water and the dead fish.
“The trout look good though,” said Jeanne. “I’m not too worried if it is just the catfish. I wouldn’t let my kids or dog play near the dead fish, but I wouldn’t have any problem eating any of the trout that have come out of the lake. They all look good.”
Local fishing guides have been keeping an eye on the situation also. “They are just as interested in the health of the lake as anyone,” said Jeanne, and there don’t seem to be any new occurrences of dead catfish. A couple of bass, one or two, came up dead according to Jeanne. It had been reported by Fish & Wildlife that a small number of dead or dying Largemouth Bass or Pumpkinseed were observed as well.
“Sometimes the trout that get planted die,” said Jeanne, “the planting process is hard on them, and sometimes people doing catch and release are too rough on the fish and they die anyway.”
CDFW collected fish carcasses from around the lake and performed necropsies at the department’s fish pathology lab. Necropsy results indicate that Columnaris bacteria may have been a contributing factor in the fish mortalities.
Columnaris outbreaks are naturally occurring in the environment and typically occur when water temperatures are warm. Other factors along with weather that may have played a part in the fish die-off are Dixie Fire runoff or a spring turnover event. Columnaris isn’t considered a risk factor for humans, and the bacteria is no known to transfer to humans.
CDFW and its partners will continue to monitor the fish population at Lake Davis. The public is encouraged to report dead or sick fish through CDFW’s Wildlife Incident Reporting System.