MANGROVES The Silent Sentinels
Debkumar Bhadra* and Dr Grinson George, Honorary Project Coordinator, CPR EEC, Port Blair Six years back, on the fateful 26th day of Dec 2004, when the giant tsunami waves struck A&N Islands, there was absolute mayhem. Everybody ran uphill to protect themselves, yet those nearest to the sea, stood firm and bore the burnt of natures fury silently, for they bear on their back the responsibility of protecting our coasts and they did it with firm determination. Who are they? They are the Mangroves; the silent sentinels of our coasts. Mangroves are salt tolerant tree species that grows in the saline marshy areas between the shore and the sea, called the inter-tidal zone, in the tropical and sub tropical latitudes. They are found growing along the coasts, bays, estuaries, lagoons, creeks and backwaters which are exposed during low tide and flooded by sea water during high tide everyday. Globally there are nearly 70 species of true mangroves found dominating three quarters of the tropical coastline. Indonesia has the largest area under mangroves (37% of global average) followed by Brazil and Australia. India being in the tropical and sub-tropical latitudes, harbour 47 species of true mangroves spread over an area of 6749 sqKm (7% of global average), of which Baitarkanika (Orissa) has 31 species, the Sunderbans (WB) with 2000 sqKm has 40 species. The Andaman and Nicobar Islands with 1190 sqKm under mangrove swamps has 34 species. More than individual trees, mangroves form a characteristic saline woodland or shrubland habitat called a mangrove swamp, mangrove forest or simply mangal. Their unique roots besides providing support and obtaining nutrition from the soil, also helps in oxygen intake from the air through lenticles and pneumatophores which are seen projecting out of the mud, like fingers in great numbers around mangrove swamps. Further the branched network of prop-roots act as barrier against wave action besides slowing down the flow of water preventing erosion as well as enhancing sediment deposition. Their role as a shield against tropical winds, storms, cyclones
and tsunamis, especially in reducing the loss to life and property are also known universally. Mangrove are also home and breeding ground for a great variety of fishes, reptiles, crabs, sea snail, shell fishes, algae, sea turtles, birds, butterflies, insects etc. Salt water crocodile found in mangrove swamps are the largest among the crocodiles. The largest population of wild tiger “The Royal Bengal Tiger” lives in the mangroves of Sunderbans. “Atlas moth” found in mangroves are the largest among moths. “The crab eating Macaque” endemic to these islands has adapted to eating crabs and living in mangroves. There are also a lot of other species including humans who directly or indirectly dependent on mangrove ecosystem for their survival. The 2004 devastating tsunami had damaged large tracts of mangroves in these Islands. Humans are also exploiting mangroves for personal gains. Several R&D organisations, NGO’s and environmentalists are advocating relevance and the need for protecting mangroves. Department of Environment and Forests are making efforts to regenerate those mangroves in a bid to bring back the ecosystem to life. We being intricately related to the unique ecosystem, it is imperative for us to understand their importance and appreciate their role in island ecosystem. Its time we repay those silent sentinels with our love, care, and protection for their contribution in sustaining our life. References : - MFF, India 2010. Mangroves: Soldiers of our Coasts, New Delhi, TERI
- Wikipedia, the online free encyclopedia Acknowledgement : Mr P Rajan, SRF, SACON * For correspondence : Debkumar Bhadra, Shore Point Bambooflat, S Andaman-744107, email : debkumar_bhadra@yahoo.com