Smithville Lake Fish Die-Off
Dan Wigmore, MLRA Science committee has discovered a similar “Crappie” experience in the U.S. This documented occurrence would appear to verify Dr Laing’s initial impression of “Columnaris” being the culprit. Please read below.
Subject: Smithville Lake Fish Die-Off
I have completed the initial investigation of the Smithville Lake crappie die-off. The kill is exclusively black crappie so far. The black crappie population is in transition from a stunted, older population to a younger, faster growing population. I will be doing some age analysis of the dead to determine if this is the case. The fish look fine until you look at their gills. They have lesions on their gills suggesting an outbreak of Columnaris flexibacter bacteria. I took some sick/dying fish to Devona Wierich, our Fish Pathologist, today and she confirmed the lesions are Columnaris. She will also be looking for other possible contributing factors in coming days.
Columnaris is always present in fish, but typically becomes an issue only in stressed fish. Our water temperatures have been slow to warm this year creating an ideal condition for these bacteria to thrive. Couple this with older, stunted fish and you have the recipe for what is happening. The good news is we’ve wanted these fish out of the system for several years, just not this dramatically!
The take-home message to fishermen should be that this, while dramatic, is a fairly natural occurrence. Any crappie they catch, are safe to eat and that this may continue for a few more days. I will continue to monitor the situation until the event is completed. Picking up thousands of dead fish scattered over a couple thousand acres is impossible. Given the expected heat in the coming days, the fish should decompose very rapidly. Scavengers are also removing many of the carcases. There are also no water quality issues causing the fish kill.
Please pass this information on to your staff who may have to deal with questions from the public.
Fisheries Management Biologist
Missouri Department of Conservation
1 Victory Drive, STE 100
Liberty, MO 64068