<smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="City" downloadurl="http://www.5iamas-microsoft-com:office:smarttags"><smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="country-region" downloadurl="http://www.5iantlavalamp.com/"><smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="place" downloadurl="http://www.5iantlavalamp.com/"> Planktonic flagellates in relation to pollution in Visakhapatnam harbour, east coast of India </smarttagtype></smarttagtype></smarttagtype>

Abstract

25-32One year study (1994-’95) on planktonic flagellates at four selected stations along a decreasing gradient of pollution in the North Arm of Visakhapatnam harbour revealed as many as 17 species. Dinematomonas littorale, Dunaliella sp., Spumella sp., and Chromulina sp. were predominant. At St. I close to sewage outfall, where the waters are characterised by poor transparency (mean 0.75m), fluctuating salinity (5.21-33.4 ‰), low dissolved oxygen (0.0-5.53 mg/l) and relatively high temperature (max. 35.4°C), Dunaliella sp. (40%) was dominant. Downstream (st. IV) with improved water quality (transparency 2.59 m; stable salinity 27.7 ‰; dissolved oxygen, 3.72 mg/l), Dinematomonas littorale (43.3 %) was the principal inhabitant. Overall, there was considerable heterogeneity in species composition and relative abundance of flagellates attributable to differences in the prevailing water quality. Based on Principal Component Analysis (PCA), it was possible to distinguish the flagellate populations into two distinct assemblages. Of these, Spumella-Peridinium assemblage was characteristic of polluted conditions at the outfall (st. I), and the Chromulina – Sphenomonas assemblage was noticed at st.IV with improved water quality