Channel Catfish Pond Effluents

Abstract
Water samples were collected four times a year for 2 years from the surface and bottom of 25 ponds used for commercial culture of channel catfish (Ictalurus punctatus) in central and west-central Alabama. Samples were analyzed for 5-d biochemical oxygen demand (BOD5), nitrite-nitrogen, nitrate-nitrogen, total ammonia nitrogen, total Kjeldahl nitrogen, total phosphorus, soluble reactive phosphorus, suspended solids, volatile solids, settleable solids, pH, and dissolved oxygen. Ranges for variables were as follows: BOD5, 1.9–35.54 mg/L; settleable solids, 0–1.8 mL/L; suspended solids, 5.2–336.7 mg/L; volatile solids, 0.02–221.0 mg/L; total phosphorus, 0–1.85 mg/L; soluble reactive phosphorus, 0–0.074 mg/L; total Kjeldahl nitrogen, 0.58–14.04 mg/L; total ammonia nitrogen, 0.008–8.071 mg/L; nitrite-nitrogen, 0.001–1.410 mg/L; nitrate-nitrogen, 0–6.661 mg/L; dissolved oxygen, 0.8–16.8 mg/L; and pH, 4.9–9.5. Concentrations of water quality variables were skewed towards the lower ends of these ranges. Occasionally, concentrations of some variables were higher than those normally encountered in natural streams and exceeded recommended effluent concentration limits.