Estudo do efeito das pescarias no balanço trófico do ecossistema estuarino Bons Sinais

Abstract

The increasing demand for marine animal protein has contributed greatly to the reduction of fish stocks, which in a way has caused direct implications in the food chain, thus giving rise to intra and interspecific competitions, and the cannibalization reflected in the struggle for the survival. Therefore, the general objective of this work was to study the effect of fisheries on the trophic balance of the Bons Sinais estuarine ecosystem. Monthly collections of four species of commercial importance were made in August, September, October and November, in which the stomach contents, and with the aid of the FishBase platform to confirm the trophic level. In the first two months the species Arius dussumieri were observed; Thryssa vitrirostris; Pomadasys kaakan; Johnius dussumieri; in October those of Thryssa vitrirostris; Sardinella albella; Hilsa kelee; Johnius dussumieri and for the last month Hilsa kelee; Johnius dussumieri; Thryssa vitrirostris and Pomadasys kaakan. Most of the analyzed species are considered carnivorous and have as main diet crustaceans and small pelagic fish. When the fisheries of the analyzed species are moderate the ecological impacts to the ecosystem are smaller, different from when the intensity is low or high where it causes significant damages to the ecosystem.