Unfortunately, under conditions of heavy stocking and feeding rates, optimal water quality is difficult to maintain. It is also impossible to control rapid temperature fluctuations in the pond water because of the large surface area and shallow depths characteristic of most commercial catfish ponds. Several ongoing research projects are developing methods to prevent this disease. Laboratory experiments indicate that various chemicals may be effective in controlling the development of fungal infections. Formalin was also effective as a postinfective treatment in reducing mortalities.
Copper sulfate appears to be toxic to catfish held at low temperatures under laboratory conditions.
Studies are underway to evaluate the strategic use of chemicals to control this disease in commercial catfish ponds. Although copper sulfate and formalin appear to have some potential for controlling Winter Kill, their routine use cannot be recommended until pond studies are completed. These studies will evaluate their effectiveness under typical culture conditions and will study the effect of long-term use of chemicals on the fish and the environment. Prevention Minimize stress and handling. Clear up ongoing disease problems before winter.