Bioaccumulation of heavy metals in Metapenaeus monoceros (Fabricius-1798) from Krishnankotta (Kodungallur), Moolampilly (North & South), Vallarpadam of Central Kerala.

Anthropogenic activities led to the contamination of estuaries of Central Kerala to a great extent. Heavy metals disposed to estuaries through industrial discharge, yard runoff, agricultural activities and storm drains shows a bioaccumulation in the tissues of aquatic animals. In the present study Metapenaeus monoceros, the speckled shrimp and associated water and sediments were collected from four different sites of Central Kerala Division, to gauge the accumulation of heavy metals. Atomic Absorption Spectrophotometer was performed for the analysis of heavy metals like Pb, Fe, Cd, Cr, Mg and Zn in muscle tissue of Metapenaeus monoceros. The results revealed that the level of heavy metals accumulation in the muscle tissue of Metapenaeus follows in descending order of Mg > Zn > Fe > Pb > Cr > Cd during the period from March 2021 to June 2022. The mean cluster of heavy metals in water at all trail places follows in descending order of Mg > Zn > Fe > Pb > Cr > Cd. Elemental analysis of sediment samples revealed that mean value of Mg and Fe were found to be higher. While mean values of Cd and Cr are within the permissible limit. Study indicates the ability of crustaceans to accumulate heavy metals to detectable levels. Knowledge of heavy metals concentration in biota, water samples and sediments are important both with respect to nature management and human consumption of shrimp.