<smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="place"> Vertical distribution of phytoplankton around Andaman and Nicobar Islands, Bay of Bengal </smarttagtype>

Abstract

<smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="PlaceType"><smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="PlaceName"><smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="place"> Vertical distribution of phytoplankton in the upper 200 m water column was studied at 5 stations around the Andaman islands during October, 1996. About 143 species, belonging to 8 classes of algae are identified. Cyanophyta, particularly <i style="">Trichodesmium erythreae</i>, contributed most to the biomass but the species diversity was maximum for Bacillariophyceae and Pyrrophyceae. Dense maxima were noted at ~25 m depth in waters of the Bay of Bengal side and less dense maxima at surface in waters of the Andaman Sea side. The maxima of Pyrrophyceae occurred up to 50 m depth and that of Bacillariophyceae in the 25-75 m depth range. A vertical stratification was also observed for several species. There are differences in hydrographic features between the Bay of Bengal and Andaman Sea waters. In the former, a tongue of warmer, more saline water present at 25-150 m depth, originating from the Arabian Sea, apart from biotic factors, is held responsible for differences in the phytoplankton distribution on the two sides off the islands. </smarttagtype></smarttagtype></smarttagtype>