EFFLUENTS QUALITY DURING THE GROW-OUT PHASE OF THE AMAZON SHRIMP Macrobrachium amazonicum

Abstract

In recent years shrimp culture farms have been one of the most growing sectors in aquaculture. Research has been carried out in order to establish a sustainable production maintaining profit and low environmental impact. Current investigation analyzed source and effluent water produced during the final grow-out phase of the Amazon shrimp (Macrobrachium amazonicum). Twelve natural-bottom ponds, with continuous water flow and stock density comprising 40, 60, 80 and 100 young shrimps/m² were analyzed. The experiment design comprised totally randomized blocks with four treatments and three replications. Microbiological analyses for Escherichia coli was attempted, coupled to physical and chemical analyses for pH, temperature, total suspended solids, total nitrogen, nitrite, nitrate, biochemical oxygen demand and chemical oxygen demand of water supply and pond effluents. Results show that whereas effluent quality complied with current legal rules, there was no significant difference between supply and effluent water for the analyzed variables and between stock densities. Under the conditions investigated and the intensification of culture in the final grow-out phase up to a density of 100 young shrimps/m², the production of M. amazonicum reveals low potential for environmental impact for the variables analyzed.

KEYWORDS: effluent; environmental impact, shrimp culture, water quality.