NORTH LIBERTY–The North Liberty Parks Department received a call on May 26 from a resident regarding a fish kill at Goose Lake. City personnel responded immediately and discovered many fish dead or dying along the shoreline.
Paul Sleeper, fish biologist with the Iowa Department of Natural Resources visited the site within two hours and determined that the fish were infected with a disease called Flavobacterium Columnare, a common bacterial infection found in many home aquariums. The disease is also known as Columnaris, Cotton-Wool, Cotton-Mouth, Flexibacter Columnaris, and Mouth Fungus.
According to Sleeper and information obtained from Georgia State University, Columnare disease is caused by the bacteria Flavobacterium Columnare. This common bacterial infection may infect many fish species in local ponds, including Bluegill, Catfish, Largemouth Bass and Black Crappies. It is highly contagious among fish and can spread rapidly. The bacteria are most prevalent after water temperatures reach 65-70 degrees from late May to late June. The bacteria levels may increase after major rainfalls that supply additional nutrients to the ponds on which the bacteria thrives. Fish that are under spring spawning stress are most likely to succumb to the bacterial infection. After the stress of the spring spawn is over typically the effects of the bacteria are greatly reduced.
City officials say people might notice during the next few weeks are fish along the shoreline either dead or alive partially covered with a white film or white spots. It is observed mainly on the head but also is seen as fuzz on the fins and gills. The body of the fish may become ulcerated and the fins frayed.
Although Flavobacterium Columnare 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 Sleeper. This is a naturally occurring event, said Sleeper, and is best handled by letting nature run its course.
North Liberty city officials emphasize there is no health risk to humans. Humans are not a host to this fish disease and fish that are caught may be touched, cooked and eaten as normal.
Currently the Parks Department is monitoring the fish at all City ponds and have picked up and disposed of dead fish. Goose Lake has been hit the hardest but all ponds in town have shown signs of the disease.
For more information, contact Guy Goldsmith, Parks/Buildings/Grounds Superintendent, City of North Liberty at (319) 626-5700.