Impact of changed trophic status on the zooplankton composition in six water bodies of Dharwad district, Karnataka state (South India).

The present paper cites results of zooplankton composition that carried out in the six water bodies of Dharwad district during September-November 2004 (post monsoon) and February-April 2005 (pre monsoon). Comparison of the obtained results with those of earlier investigations performed during 1978-1979 showed that changes have occurred in the interval. The total zooplankton composition is significantly changed in all the six water bodies. The lower value of Sorenson and Jaccard indices suggests that significant changes have occurred in the group rotifera and cladocera whereas the higher values for copepoda group suggests least changes. Concurrent occurrence of six Brachionus species in Unkal Lake, four species in Kelgeri, Nuggikeri and Navalur tanks indicate intensified eutrophication. If these habitats have to be preserved for their intended use there is a need for sustainable and holistic management.