Sediment as an indicator of health of tidal wetland ecosystem

Abstract

Wetlands are classified as tidal and non-tidal wetlands. Tidal wetlands as their name suggests, are closely linked to our nation's estuaries, where sea water mixes with fresh water to form an environment of varying salinities. Large variation in salinity facilitates processes which lead to sediment deposition and therefore estuaries and creeks are the ultimate repositories of land derived material including waste generated and released to the environment by the human population. Further, heavy metal contents in sediments are an accepted and widely used indicator of anthropogenic pollution over time. Tidal wetlands represent the largest component of the terrestrial biological carbon pool and thus play an important role in global carbon cycles. The health of wetlands depends on the quality and quantity of water that reaches them and also bioavailability of metals within sediments and water. Present study has proved that the bioavailable metals if released from sediment to water column due to processes of either natural or anthropogenic or both, can cause potential risk to water quality and associated biota and in turn health of the wetland ecosystem.