Comparative water quality and channel catfish production in earthen ponds and a biofloc technology production system

ABSTRACT

This 210-day study compared variation in water quality and fish growth for channel catfish (Ictalurus punctatus; 47 g/fish) stocked in earthen ponds (1.5 fish/m², 14,820/ha) and in a biofloc technology (BFT) production system with high-density polyethylene-lined rectangular tanks (12.6 fish/m², 126,000/ha). Feed input and culture environment affected water-quality dynamics. In ponds, phytoplankton uptake predominated and little nitrification occurred, whereas in the BFT system phytoplankton uptake and nitrification maintained low ammonia-nitrogen concentrations. Size classes of fish were skewed toward the larger market sizes in ponds and toward smaller market sizes in the BFT system. Mean final fish weight was 630 g/fish in ponds and 542 g/fish in the BFT system. Despite these differences, fish yield was higher in the BFT system (7.7 kg/m³ v. 1.5 kg/m³) because of the greater initial stocking rate.

KEYWORDS:

• Biofloc technology
• channel catfish
• earthen ponds
• Ictalurus punctatus
• market-size fish
• water quality

Acknowledgments

We thank Greg O’Neal, Paxton Harper, and William Schiederer for their assistance during this study. Mention of trade names or commercial products is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the U.S. Department of Agriculture (USDA). USDA is an equal opportunity provider and employer.