Introduction

Mangroves constitute one of the important parts of an estuarine ecosystem and in fact form an icon for the estuarine ecosystem. Mangrove wetlands are a multiple use ecosystem that provides protective, productive and economic benefits to coastal communities. Mangroves contribute to the stabilization of the shoreline and prevention of shore erosion. They serve as a barrier against storms so as to lessen damage to coastal land and residents. The dense network of supporting roots and breathing roots give mechanical support to the tree and trap the sediments. Without mangroves, all silt will be carried into the sea, where turbid water might cause corals to die. Mangrove trees act as sinks, which concentrate pollutants such as sewage, toxic minerals, pesticide, herbicides, etc. Before the agricultural interventions by the humans these were areas pristine intact patches of mangroves. However, after introduction of agriculture, good portions of shallow estuarine areas were reclaimed by preparing earthen embankments for raising of salt tolerant rice varieties like Kagga. Farmers plant rows of mangrove trees just outside these bunds to fortify them from collapse. This traditional system of estuarine cultivation with mangrove planting was a sustainable system. Maintenance of some patches of mangrove forests as sacred, as in the Masurkurve Island in the Aghanashini estuary, dedicated the deity Babrudevaru, is a notable example of traditional conservation.

The current issue highlights the ecological and economic importance of mangrove ecosystem. Vegetation cover with mangroves aids as bio-shield protects the shore from erosion. Stabilized sand dunes, natural safety barriers of beaches, are the contribution of psammophytes, at no cost to human economy. Plant roots are effective in stabilizing loose sand and protecting it from erosion by waves or wind.  The local community will be benefited from good vegetation on the sea beach due to various non-timber products and tourism potential. Considering the large scale destruction of these fragile habitats, there is an urgent need to protect the shore with mangroves bio-shield, which also help in sustaining the local livelihood. Bio-shielding, referring to raising of green walls using appropriate plant species, is a more recent term applied for shore protection with the help of vegetation. Bio-shielding serves the dual purpose of raising the sand dunes as well as increasing the protective cover of the vegetation. Not just the sea beaches but even the backshore has to be managed under integrated coastal management programme.