Mercury levels in Perna viridis from the north coast of Sucre State, Venezuela

N Rojas,K Chung,M Lemus,L Rojas,G Martínez,Y Ramos

doi:10.7773/cm.v35i1.1362

Abstract

Mercury levels were determined in green mussels, Perna viridis, from two localities of Sucre State (Venezuela): Chacopata and Río Caribe. Specimens were captured in the intertidal zone from February to December 2003. They presented anteroposterior lengths ranging from 18 to 113 mm and were classified, according to their sexual maturity, as juveniles or adults. Mercury was determined by flame atomic absorption spectrophotometry and the method of analysis was validated using certified standards. Seasonal variations were significant at both sites. Highest mercury concentrations in the Chacopata specimens were recorded during February (mean value of 0.432 ± 0.472 µg g–1 d.w.) and in the Río Caribe specimens during April (mean value of 1.129 ± 0.763 µg g–1 d.w.). No relation between mercury levels and sexual maturity was found at Chacopata, but a relation was observed at Río Caribe. Immature organisms showed the highest concentrations (0.471 ± 0.679 and 0.688 ± 0.894 µg g–1 d.w. for males and females, respectively).

Highlights

Mercury is the most toxic metal and has harmful effects on marine organisms
Mercury levels were determined in green mussels, Perna viridis, from two localities of Sucre State (Venezuela): Chacopata and Río Caribe
Due to the bioaccumulation of heavy metals in the tissue of some molluscs, this study aims to determine the monthly variation of mercury and its relation to sexual maturity and size of P. viridis from two sites in Sucre State: Chacopata and Río Caribe

Summary

Introduction

Once incorporated within the cell it can link to ligands with sulfhydryl groups such as glutathione and metallothioneins (Hultberg et al 2001). These molecules intervene in metal accumulation, metabolization, and depuration processes. Pollutants, including mercury, can induce oxidative stress in cells, generating a large number of free radicals (Livingstone 2001). These radicals can cause cell death if they are not checked by antioxidant mechanisms, primarily by antioxidant enzymes, glutathione, and metallothioneins, which participate in the elimination of reactive species (Regoli and Principato 1995).

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