Decline of mangroves - A threat of heavy metal poisoning in Asia

Mangroves are coastal habitats, contributing significantly to the well-being of coastal community, especially in Asia wherein over 70% of human population depends on the coastal resources for food and employment. In recent decades the uncontrolled run off materials from agriculture and industry are entering in to the mangrove system and polluting it alarmingly. The pollutants in particular, heavy metals (Hg, Cd, Ni, Pb, Cu, Cr, and Zn) enter into this system and maroon the mangrove substrate soil. Due to this property, there is a wide accumulation of heavy metals in mangrove flora and fauna. Obviously any small change in mangrove habitat has profound impacts on adjacent coastal systems including seagrass beds and coral reefs. This results in alteration of density and diversity of coastal life which is interlaced with coastal economy. Moreover, coastal people in Asian region are highly prone to heavy metal contamination due to diminishing of mangroves which will release the deposited heavy metals, which will reach man in several ways. It is the time to control further decline of mangroves and to encourage reforestation in coastal Asia for the well-being of the entire subcontinent. (c) 2014 Elsevier Ltd. All rights reserved.