Mangrove stands of Andamans vis-a-vis tsunami

摘要

The earthquake (9.0 Richter scale), which struck Andaman and Nicobar Islands on 26 December 2004 and the consequent tsunami have caused considerable change on the mangrove stands of Andamans. The tidal waves that swamped the mangrove stands have affected the giant fern Acrostichum aureum and the aquatic sedge Fimbrisstylis littoralis. The true mangroves, viz. Rhizophora spp, Bruguiera spp, Avicennia spp, Sonneratia spp, etc. have also got affected in various degrees based on their physiological response to the continuous inundation/exposure under the changed scenario. In South Andaman, in particular localities 30-80% of mangrove stands got affected. In Middle Andaman the impact is negligible, whereas in the North Andaman due to the elevation of land, the sea water is not reaching some of the mangrove stands. Some visible impact has also been felt in the habitat of various fin fishes and shell fishes.