Enhancing water use efficiency in monoculture ofLitopenaeus vannamei:Impacts on pond water quality, waste production, water footprint andproduction performance

Abstract

We studied the effect of rearing densities of Pacific white shrimp,Litopenaeus vannameiin three densities withthree replicate treatments [T1: 0.4 million post - larvae (PL) ha−1,T2: 0.5 million PL ha−1,T3: 0.6 million PLha−1] and water cutback approach on rearing environment, water use efficiency, water footprint and productionperformance. Conditional water exchange was carried out based on water quality parameters. Water qualitysuitability index was very good (7.5–9.0) up to 13th, 10th and 5th week of culture in T1,T2and T3, respectively;which was attributed to rearing density, smaller - sized shrimp and low early feed input. Optimum rearing densityof 50 PL m - 2(T2) led to total water use of 3.25 × 104m3. It was seeming as a way to improve shrimp pro - ductivity (10.58 t ha−1120 d−1), consumptive water use index (1.72 m3kg - 1biomass), total water footprint(1229 m3t−1biomass) and net consumptive water productivity (USD 1.28 m - 3). L.vannameiculture with low tomoderate water exchange as in T2, helped uphold water quality suitable for the shrimp growth, improved wateruse efficiency (0.58 kg biomass m - 3water), minimized sediment load (45.3 m3t - 1biomass), effluent outputs(0.63 × 104m3), pumping cost (USD 30.1 t−1biomass produced), and ratio of output value to the cost of cul - tivation (1.97). Thefindings and advancement in knowledge would offer the basis to augment shrimp rearingefforts and the water management approaches will help in preventing the production of waste and effluent while increasing water use efficiency and production performance