Metal bioaccumulation in edible fauna and phytoremediation by mangroves in the Mandovi Estuary, India

Abstract

The study investigated bioaccumulation of metals in edible bivalves and crustaceans in the Mandovi Estuary, assessing the potential toxicity to biota and human consumers. Additionally, it examined the phytoremediation potential of mangrove species in the Mandovi Estuary. The concentration of essential (Fe, Mn, Zn, Cu, Co and Ni) and toxic (Hg) metals exceeded the upper crustal average, indicating their anthropogenic contribution to estuarine environment. Analysis of Contamination Factor revealed moderate to very high level of metal contamination in sediment. The metals Fe, Zn and Cu were preferentially accumulated by bivalves and crustacean, likely due to their essential roles in growth and metabolic process. However, the presence of Fe, Mn, Zn, Cu and Hg concentrations above permissible limits in biota highlights a risk of toxicity for both aquatic organisms and their consumers. Mangrove species such as Sonneratia alba, Avicennia marina, Aegiceras corniculatum and Rhizophora mucronata demonstrated a Translocation Factor (TF) above 1, confirming their capability to accumulate and translocate metals effectively. This finding underscores the potential of these mangroves for phytoremediation of metal pollution in the Mandovi Estuary.