Avaliação da contaminação do caranguejo Portunus pelagicus por metais pesados no Estuário Espírito Santo na Matola, Moçambique

Abstract

This study assessed the contamination of the aquatic environment of the Espírito Santo Estuary located in the province of Maputo in Mozambique. The evaluation was performed through the identification and quantification of heavy metals As, Cu, Mn, Pb and Zn by XRF and ICP-OES respectively, in samples of the crab Portunus pelagicus. The evaluation considered the analysis of samples of complete crab and its dried tissues, namely, the carapace, muscle and hepatopancreas. The crab Portunus pelagicus is widely used as a bioindicator of environmental pollution in estuarine waters. The contamination of aquatic ecosystems by heavy metals has been the subject of several studies due to their bioaccumulation and biomagnification and contributes significantly to the degradation of aquatic ecosystems and puts human health at risk. The values ​​of metal concentrations in crab were compared with the limits of metal concentration in crab established by the WHO to measure the level of pollution in the estuary. All metals showed concentrations above the value permitted by the WHO: [As] > 1.0 mg/Kg; [Cu] > 30.0 mg/Kg; [Mn] > 5.50 mg/Kg; [Pb] > 2.0 mg/kg; [Zn] > 30.0 mg/Kg. These (indicative) results show that the aquatic environment of the Espírito Santo Estuary is polluted and poses a risk to aquatic ecosystems and human health. The main sources of pollution identified in the estuarine waters studied were port, fishing and agricultural activities. Awareness campaigns for both industries and local communities on the sustainable use of water resources, combined with preservation, conservation and monitoring actions, are essential for maintaining the different forms of life that exist in this estuary.(TRADUÇÃO NOSSA)