Description of spatial and temporal water quality and nitrogen dynamics in a split-pond aquaculture system

Production limits have been maximized in earthen pond (EP) aquaculture. Pond design innovations may increase limits of catfish production by enhancing nitrogen processes. The split-pond system (SPS) partitions a pond into fish (20%) and waste treatment/oxygen production compartments (80%). In 2010, an SPS and EP were stocked (March) and harvested (October) with 25,000 catfish ha-1. Water quality (DO, pH, temp, ORP, CHL-a), nitrogen dynamics (TN, TAN, NO2-, NO3-), nitrogen pathway estimation, and nitrogen budgets were compared. In the waste treatment compartment, maximum DO concentrations exceeded 40 mg L-1, whereas ORP values provided favorable denitrification conditions. October EP NO2- concentrations were 3-4 mg L-1; 10-fold greater than the SPS. Feed (~90%) and fish (~60%) were the greatest source and sink of nitrogen, respectively. The SPS may be a promising pond design for the catfish industry through enhanced nitrogen removal and potential opportunity for increased production.