The Use of Sodium Carbonate Peroxyhydrate to Treat Off-Flavor in Commercial Catfish Ponds

Sodium carbonate peroxyhydrate (SCP) was applied to seven commercial catfish ponds in Mississippi to study the effects of treatment on fish flavor and pond ecology. The seven ponds were treated on alternate days in the morning with two doses of SCP at 55 kg hectare⁻¹ (average depth 1-1.6 m). In three of the ponds, a potent 2-methylisoborneol (MIB) producing planktonic Oscillatoria chalybea-like species that was initially present was absent from the water column after treatment. In addition, the fish from two of these ponds were judged on-flavor 7 to 10 days after treatment. The off-flavor chemicals in three other ponds were diminished when measured seven days after treatment and fish were harvested from two of these ponds 10-14 days after treatment. The fish from the other two ponds were harvested 21 days after treatment. In the sixth pond, the predominant algal species was a 2-methylisoborneol producing O. chalybea-like species at 380 cells ml⁻¹ and the treatment was ineffective. The treatment was most successful when off-flavor was less than two months duration and where application of the chemical was accomplished uniformly over the entire pond surface.