Submitted to: North American Journal of Aquaculture
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/4/2008
Publication Date: 10/13/2008
Citation: Torrans, E.L. 2008. Production Responses of Channel Catfish to Minimum Daily Dissolved Oxygen Concentrations in Earthen Ponds. North American Journal of Aquaculture 50(4):371-381. Interpretive Summary: Channel catfish were produced in ponds in which the lowest daily dissolved oxygen concentrations were controlled with aeration. Allowing the oxygen to fall to 2.7 ppm in the morning (compared to ponds maintained at 4.4 ppm) resulted in slightly reduced feed consumption and production. The data agree well with a previous published study. It is recommended that catfish farmers maintain the lowest daily dissolved oxygen concentration in their ponds at 2.3-2.5 ppm as a compromise between high aeration costs and reduced production.
Technical Abstract: The purpose of this study was to determine the effects of the minimum daily dissolved oxygen (DO) concentration on production parameters of channel catfish Ictalurus punctatus in earthen ponds. Fifteen one-acre ponds (5 ponds per treatment) were managed as High Oxygen (minimum DO concentrations averaging 4.4 ppm from June through September), Medium Oxygen (minimum DO concentrations averaging 2.7 ppm), or Low Oxygen treatments (minimum DO concentrations averaging 2.3 ppm) using one 5-hp electric paddlewheel aerator per pond. Fish in the High, Medium, and Low Oxygen treatment ponds consumed a mean total of 14,008, 13,212, and 12,607 lbs/acre of 28% protein floating feed, respectively. Trends in net production paralleled total feed consumption, with net production averaging 5,772, 5,278, and 5,113 lbs/acre in the High, Medium, and Low Oxygen treatments, respectively. No visible stress responses were observed in any ponds during this study. Total aeration averaged 5,245, 2,518, and 1,337 hp-hr/acre in the High, Medium and Low Oxygen treatments, respectively. Treatments with higher minimum DO concentrations had significantly higher nitrite nitrogen, suspended solids, chlorophyll a and pH, and lower Secchi disc visibility, alkalinity and hardness, however, no water quality parameters exceeded the normal acceptable range for channel catfish. While cost of electricity must be considered, maintaining a minimum daily DO concentration of 2.3 - 2.5 ppm is suggested as a compromise between maximizing fish feed consumption and production while minimizing aeration costs.