COMPARISON OF 2 TECHNIQUES FOR DETERMINING COMMUNITY RESPIRATION IN TROPICAL FISH PONDS

Two techniques for deter-mining community respiration in organically f ertilized tilapia grow-out ponds were compared: (1) whole pond respira tion (WPR) from changes in nocturnal dissolved oxygen concentrations c orrected for diffusion, and (2) the sum of water column (WCR), benthic (BR), and fish respiration (FR), components of community respiration. Mean WPR (0.568 g O2 m-2 h-1) was significantly higher (P < 0.01) tha n mean sum of community respiration components (0.401 g O2 m-2 h-1). M ean WCR, BR, and FR were 0.319, 0.068, and 0.015 g O2 m-2 h-1, respect ively. Indirect determinations of community components by difference o f WPR and the sum of the other two components will be significantly hi gher than in situ determinations.