Missouri reports unusual number of dead fish
Friday, April 28, 2006
JEFFERSON CITY, Mo. -- An unusually high number of fish kills across Missouri this spring likely is related to the weather and should not cause serious concern, the Department of Conservation said Thursday. The department typically gets one report of dead fish a week in the spring, but this year it has been receiving about five reports a week from all over the state and involving every kind of water body, said Leanna Zweig, a resource scientist who oversees fish kill investigations for the department.
Zweig said every fish species has been affected, with most kills involving 50 to 100 fish.
Conservation Department fish pathologist Devona Weirich said that while the number of fish kills this spring is unusual, the phenomenon itself is not.
"Fish experience a lot of stress in the spring," Weirich said. "They often haven't eaten very well during the winter, and they go right into spawning, which can be exhausting. Their immune systems are very weak, and this results in some fish dying."
The department said Missouri's waters have been affected by an unusually dry, warm spring. Water temperatures are higher than normal, and water levels in streams and reservoirs are below normal, especially in southwest Missouri. Water quality is worse than usual, and fish are crowded into less space.
In many cases, reports have involved dead fish with an advanced growth of bacteria or fungus covering their bodies. Spring fish kills usually happen when external parasites damage the skin or gills of fish, leading to bacterial infections.
"That is what seems to be going on in all the reports we have received so far," Weirich said. "We don't have any reason to suspect pollution or other environmental problems. It's basically natural causes. We simply have a worse-than-normal case of what we see every spring."
On the Net:
Conservation Department: http://www.mdc.mo.gov