The dead fish on Fountain Lake that have been reported over the weekend likely died from a bacterial infection that is heightened during spawning and an increase in water temperature, said a Minnesota Department of Natural Resources official on Tuesday.

Area Fisheries Supervisor Hugh Valiant said though the DNR pathology lab has not taken any specimens from Fountain Lake to confirm this, it seems probable that the fish died from an infection called columnaris because all of the conditions are present that are consistent with the infection.

Valiant said the infection is fairly common — his office deals with anywhere between three and six lakes with the infection each year between the nine counties that he works with.

Clear Lake in Waseca has recently reported a similar situation.

Fish affected typically include blue gill, black crappie and black bullheads, though other fish can be affected as well.

Valiant said the bacterium is around all the time but manifests itself at this time of year when the water temperature is going up to the mid-70s or upper 70s and there are fish spawning. The spawning makes the fish more susceptible to infection.

Common symptoms in fish that have the bacterium include visible red sores, either around the mouth or in other places, Valiant said. Sometimes those sores will be secondarily infected by fungus, which would make them look more unsightly, he noted.

The bacterial infection ultimately causes death in the fish.

It does not affect humans, he said.

Fifth Ward Councilor Larry Anderson, a member of the Fountain Lake Sportsmen’s Club, said reports of the dead fish first started coming in on the lake last Thursday.

He said he saw mainly blue gills, sunnies, crappies and one good-sized carp that had died.

He said he tested the water temperature on Saturday and it was between 76 and 79 degrees. On Sunday it was 76.

Anderson noted he saw fewer dead fish on Sunday than a few days earlier, so he hoped the worst had passed.

If fishermen or other area residents see anything of concern they should call Valiant at (507) 362-4223, Extension 222.

Valiant said if the DNR is alerted in a timely manner, a member of the DNR staff could probably run over and get some fresh specimens to test.