Abstract
In current years, observing the concentration of heavy metals in marine biota has received much awareness as the public are more aware about the healthy environment and food. Intensity of these metals in a huge range of finfish and shellfish would give baseline information for some of the toxic metals. In the present investigation an attempt has been made to study the presence and concentration of some heavy metals in the true limpet Cellana karachiensis a gastropod mollusk which is abundantly found at the intertidal to high tidal zones of different rocky shores of Sind and Baluchistan coasts of Pakistan. In the present study two distinct anthropogenic dynamic rocky shores i.e., Clifton and Mubarak village of Karachi coast was selected to analyse the heavy metals in soft tissues of C. karachiensis which accept as a good bio-indicator mollusk to observe heavy metal pollution awareness. The concentration of zinc (Zn), chrome (Cr), copper (Cu), lead (Pb) and cadmium (Cd) in the soft tissue of the limpet C. karachiensis from two rocky shores in the Karachi coast has been measured by Atomic Absorption Spectrometer (A Analyst 700) for monitoring metal contamination of samples. Accumulation of Zn was found highest followed by Cr, Cu, Pb and Cd in the months of July and August 2019 in Clifton shores. While at the same period the highest concentration was Zn followed by Cu, Cd, Cr and Pb at Mubarak village shore. It has been observed that, C. karachiensis at Clifton shore accumulated more than heavy metals that found at Mubarak village shore. The pattern of accumulation of Heavy metals at both sites of limpets did not exhibit much difference. ANOVA single factor and student t test was done for the statistical analysis of metal contents in soft tissues of C. karachiensis of both shores at (p<0.01) and observed statistically significant differences in the amounts of the Cu, Cd and Zn elements among the limpets of both rocky shores. Same as the significant result at p<0.01 and p<0.05 was observed in between the length size of limpets at Clifton and Mubarak Village rocky shores. Correlation studies carried out for the metal concentrations in limpet and shell length of the animal which did not show significant results except Cu at Mubarak village shore. The results were compared with previous studies and discussed.