Effect of cassava waste on bioremediation of nitrogenous metabolites and shrimp growth

Abstract

Aim: Locally available cheap carbon sources, cassava waste and cassava starch, were tested for their efficiency in decreasing the nitrogenous metabolites, resulting due to accumulation of uneaten feed and excreta atthe pond bottom during intensive shrimpaquaculture. Methodology: Yard experimentwas carried out in 5001 Fibre reinforced plastic (FRP) tanks for a period of 105 days with four treatments viz., cassava waste, cassava starch, cassava waste+ cassava starch and control, replicated thrice and statistically randomized with Tiger shrimp, Penaeus monodon (1.71 g). The following water quality parameters-pH, salinity, dissolved oxygen (DO), total ammonia nitrogen (TAN), nitrite nitrogen (N02-N); microbial parameters in water and sediment-total heterotrophic bacteria count (THBC) and total vibrio count (TVC); proximate composition, fibre fractionation, carbon, hydrogen, nitrogen and sulphur content in cassava waste and cassava starch were analyzed. The growth of shrimp was also studied. Results: Shrimp growth was significantly high (p≤ 0.05) in cassava waste (11.12 g) treatment followed by cassava starch (10.4 g), cassava waste + cassava starch (9.8 g) and control (8.02 g) at the end of the experiment. Cassava waste, cassava starch and combination of both significantly decreased the concentration of metabolites and had high heterotrophic bacterial population and low total vibrio count compared to control. Interpretation: It was concluded that addition of cassava waste had positive effect on bioremediation of nitrogenous metabolites, enhancing the growth of shrimp.