Ecology, Environment and Conservation Paper

IMPACT OF RESTORATION ON ZOOPLANKTON COMPOSITION OF KELAGERI LAKE, DHARWAD (KARNATAKA STATE, INDIA)

Vijaykumar A. Kudari and Ravishankar D. Kanamadizt

Abstract

The impact of restoration i.e. eradication of macrophyles, desiltation, increase in bund height and sewage diversion on the zooplankton composition of the Kelageri lake has been studied from November, 2010 (during restoration) to April, 2012. The zooplankton taxa recorded in the present study varied from 8 to 19. The species number is reduced drastically as compared to the previous report of a maximum of 42 species In 2006-2007 (prior to restoration). The decrease in the cladoceran species composition immediate after the restoration appears to be due to the removal of macrophytes. Rotifer composition shows least similarities with all the earlier reports. The drastic decrease in number of rotifers may be attributed to the shift in trophic status i.e. from hyper-eutrophy to oligotrophy as a result of restoration program especially the diversion of sewage inflow. The copepodan composition was not affected by the change in trophic status and recorded maximum similarity with earlier reports. The disappearance of number of eutrophic indica-tor species like Brachionus calyciflorus, B. plicatilis, 13. !Meatus, B. ;lawns, B. forfirula, B. quadridentatus and B. urceolaris from the lake may be considered as hallmark sign of the healthiness of the water body. There is a need of maintainance of the current status of the lake as many anthropogenic activities are still continuing We strongly recommend to the concerned authority to take necessary action to minimize the anthropo-genic disturbances which help in sustaining the lake.