The polluting potential of shrimp farming on the aquatic environment and its effluent treatment alternatives

Author: Ana Carolina Cotta de Mello Canary (Currículo Lattes)
Supervisor: Dr Wilson Francisco Britto Wasielesky Junior
Co-supervisor: Dr Luis Henrique da Silva Poersch

Abstract

Brazil is one of the main shrimp producers in Latin America. The increase in this activity has raised concerns about its possible environmental impacts caused by the discharge of crop effluents over the aquatic environment. In view of this, this work aimed to analyze the environmental impact of a shrimp farm Litopenaeus vannamei and later evaluate the performance of different treatment methods in the removal of nutrients and total suspended solids contained in effluents from white shrimp cultivation. In chapter I, an analysis of the impact of the contribution of crop effluents to the Lagoa dos Patos estuary - Brazil was carried out, using the benthic macroinvertebrate community as an indicator. This study was on a semi-intensive shrimp farm,where it was observed as parameters of water quality the pH, dissolved oxygen, oxygen consumption and total suspended solids, being the sampling places a control region, the exit of the drainage channel of the farm and the sedimentation basin. The sediment collections for the qualitative and quantitative analysis of the benthic community were at the exit of the farm's drainage channel and in the control. The results found show that the sedimentation basin in this shrimp culture was relatively efficient. There are reductions in pH and oxygen concentration and an increase in oxygen consumption at the outlet of the farm's drainage channel. In addition, a change in the structure of the macrofaunal community was observed in the environment adjacent to the crop.As a change was observed in the environment adjacent to shrimp farming, Chapter II aimed to assess the possible removal of nutrients and suspended solids using different bioremediaters for this. This study was carried out inside an aquaculture greenhouse, where four treatments were set up: sedimentation basin, artificial substrate, wetland and hydroponic. Each treatment had its volume renewed by 10% each day, receiving water from a super-intensive shrimp crop. The parameters analyzed every two days were pH, salinity, dissolved oxygen and temperature, and, weekly, ammonia, nitrite, phosphate and solids suspended from the culture tank and treatments were analyzed.The results indicate that the sedimentation basin and the wetland provide a significant improvement in the quality of the water to be released into the environment.

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