Columnaris Affects Upper Bass Lake

A Columnaris fish kill was recently discovered on Upper Bass Lake on the reservation.  While it is infrequent on the reservation it does happen every few years. Affected fish that are still alive will be swimming slowly and may appear to have a cotton like lesions around their mouths.  The Wisconsin DNR has also put out information regarding the potential for Columnaris outbreaks and can be seen below.

The heavy rains and flooding have added additional organic material to waterways, making conditions ripe for fish kills caused by a bacterial disease called Columnaris.
Columnaris fish kills generally occur throughout the state during May and June each year and should not be confused with the viral hemorrhagic septicemia (VHS) virus which is a new disease feared to be spreading inland from the Great Lakes. Both diseases only infect fish species and are not a health risk to humans. However, people should not eat fish killed by Columnaris or VHS, and should wash their hands if they handle infected fish, because other bacteria that may be harmful to humans start feeding on the dead carcasses.
“The Columnaris bacteria is most prevalent in our lakes after water temperatures reach 65-70 degrees from late May to late June,” says Larry Damman, DNR fishery biologist. The bacteria levels increase after major rainfalls that supply additional nutrients on which the bacteria thrives into area lakes. VHS fish kills tend to occur at temperatures less than 60 degrees.”
Bluegill, crappies, yellow perch and bullheads, already stressed from seasonal spawning activities are most affected by Columnaris. The bacteria erode the fishes’ skin, causing leakage of bodily fluids and a fairly rapid death.
Although Columnaris can appear to produce large scale fish losses in a matter of several days, it usually does not have a catastrophic impact on overall fish populations, according to fishery biologists.
Columnaris was recently found in bluegills, crappies, and other panfish in Dane and Kewaunee counties. As waters warm more fish kills may be expected.