Status of Heavy Metal in the Lower Gangetic Delta: Implication of Acidification on Compartmentation

Abstract

Increased atmospheric carbon dioxide concentrations are causing greater dissolution of carbon dioxide into the estuarine water, which is the key factor behind today’s ongoing ocean acidification and subsequent compartmentation of heavy metals in the system. We conducted a long term survey on temporal variation of pH and its impact on heavy metals in the Matla estuary, situated in the central part of Indian Sundarbans. The resent study indicates the key role of acidification (major driver) in the exchange of heavy metals from sediment compartment to the overlying aquatic phase. The lowering of pH favours the process of dissolution of selected heavy metals (Zn, Cu and Pb) and promotes the transference of metallic compounds from the sediment to the aquatic phase.