Marine Organisms in Toxicological Approach for the Assessment of Environmental Risk

Three marine organisms, Mugil cephalus, Penaeus monodon and Perna viridis were exposed to cadmium, copper, lead and zinc in 24-hrs static renewal acute toxicity test in the present study. Subsequently safe concentration and the ambient concentrations in the Ennore were estimated. The calculated 96-hour LC50 values showed the sensitivity of mullet juveniles to metals are in the order of Cu>Cd>Pb>Zn. Juveniles of P.viridis were highly susceptible to copper; 96 h LC50 value was very low and was tolerant to zinc. The order of sensitivity was Cu>Cd>Pb>Zn. Post larval stages of P.monodon exposed to heavy metals in acute toxicity test revealed vulnerability towards lead and tolerant to zinc. The order of sensitivity was Pb>Cu>Cd>Zn. Ambient concentrations in Ennore creek showed that the values were above the safe concentrations derived and the coastal standards. The heavy metal concentrations would have posed a great threat for the sustainability of juveniles in the Ennore estuary. Hence, there is an urgent need to implement stringent rules to prevent pollution of creek, so that the juveniles may grow, reproduce, and thrive in their waters contributing a sustainable ecosystem for the future