Bio-ecological study of Kavoor tank in Dakshina Kannada, Karnataka, India

Abstract

Hydrological parameters along with the diversity of flora and fauna of Kavoor tank in Mangalore city, Dakshina Kannada district of Karnataka state, India was studied during February 2012-January 2013. Seasonal variation in physico-chemical parameters were analysed. Surface water temperature varied between 23.7 to 32.5 °C and pH was slightly acidic. Transparency and dissolved oxygen was low. The concentration of nitrate, sulphate, sodium and potassium were close to the permissible limits. Phytoplankton abundance is in the order of Cyanophyceae> Bacillariophyceae> Chlorophyceae> Desmidaceae. Of the six species of blue-green algae, Oscillatoria sp. and Anabaena sp.; of the seven species of Desmids, Fragilaria sp.; of the six species of green algae, Spirogyra sp. and Pediastrum sp.; and of the four species of Desmids, Cosmarium sp. were found to be more abundant. Zooplankton abundance is in the order of Copepoda> Rotifera> Cladocera> Ostracoda. Among four species of copepods, Mesocyclops sp. and Heliodiaptomus sp.; of the seven species of rotifers, Brachionus sp. and Keratella sp.; of the five species of cladocera Diaphanosoma sp.; and of the two species of ostracoda Stenocypris sp. were predominant. 15 species of aquatic plants, 10 species of fish belonging to order Cypriniformes and 17 species of birds were also recorded. Current threat status and conservation strategies are discussed.