International Journal of Fisheries and Aquatic Research

Authors
Dhinamala K, Shalini R, Pushpalatha M, Arivoli S, Samuel T, Raveen R

Abstract
Heavy metal bioaccumulation by marine organisms has been the subject of considerable interest in recent years due to serious concerns that high levels of heavy metals may have detrimental effects on the marine organisms and may create problems in relation to their suitability as food for humans. In the present study, six species of shellfish, Fenneropenaeus indicus, Fenneropenaeus monodon, Fenneropenaeus semisulcatus, Scylla serrata, Clibanarius longitarsus and Meretrix casta in Pulicat lake, Tamil Nadu, India were analysed for the presence of nickel in its gills and muscles from January 2011 to December 2012. The results showed seasonal variations in the uptake of nickel. Very high accumulation of nickel was found in the gills and muscles of Fenneropenaeus indicus during post monsoon, premonsoon and monsoon. The corresponding values of nickel present in the gills of Fenneropenaeus indicus were 1.17, 1.56 and 1.86μg/g in 2011 and 1.19, 1.58 and 1.90μg/g in 2012. Whereas for muscles, high accumulation of nickel was observed in post monsoon, summer, premonsoon and monsoon in 2011 only and values were 3.35, 6.65, 7.78 and 0.80μg/g respectively. The results of the present study have shown that the accumulation of nickel found in the gills and muscles were high in Fenneropenaeus indicus when compared to other species of shellfish. Thus, the consumption of the shellfish is safe, but does not exclude bioaccumulation risk in their meat. The present study has highlighted the need for estuarine biomonitoring to avoid possible contamination of shellfish and its consumers. The overall scenario of the shellfish accumulating high levels of nickel indicates that the Pulicat lake is polluted with undesirable elements and the risk of consuming the meat of shellfish by man and other carnivores may lead to their toxicity. Stringent control measures are necessary to control the pollution of this precious lake to reduce the bioaccumulation of toxic metals in organisms.