Impacts of shrimp farming cultivation cycles on macrobenthic assemblages and chemistry of sediments

Luisa F. Ribeiro, Gilmara F. Eça, Francisco Barros, Vanessa Hatje

Centro Interdisciplinar de Energia e Ambiente (CIENAM), Instituto de Química, Universidade Federal da Bahia, Rua Barão de Jeremoabo, s/n, Ondina, 40170-115, Salvador, BA, Brazil.

Abstract

The aim of this study was to evaluate the influence of a shrimp farm cultivation cycle in the composition of sediments and on the structure of macrobenthic assemblages. Concentrations of nutrients, Zn and Cu were significantly higher in impact than control areas. In general, the level of contaminants was highest during the harvesting period and in sites closest to the discharge of effluents. Abundances and number of taxa of benthic invertebrates were at least one order of magnitude smaller in impacted areas than in controls. The structure of the benthic assemblages was significantly different at these two treatments. The combined use of biological and chemical data showed to be efficient to provide precise answers regarding the extent of impacts caused by shrimp cultivation. The results provide the basis for a better understanding of impacts of this activity and can subsidize the development of better management practices for coastal areas.

Keywords: Macrobenthos; Metals; Nutrients; Temporal variation; Multiple lines of evidence.