Physico-chemical characteristics and zooplankton diversity in a perennial lake at Dharmapuri (Tamil Nadu, India)

Abstract

In order to assess the suitability of the Hale dharmapuri lake (Latitude 12o8’ 54”N and Longitude 78o10’ 38”E) of Dharmapuri town (Tamil Nadu, India) for inland aquaculture, this study was conducted for a period of one year (March 2015 – February 2016) under four seasons, post-monsoon, summer, pre-monsoon and monsoon. A total of 29 zooplankton species were identified qualitatively, which includes 10 species of Rotifer, 8 species of Cladocera, 6 species of Copepoda and 5 species of Ostracoda. The mean population of each zooplankton groups from all the seasons recorded was in the following order, Rotifers > Cladocerans > Copepods > Ostracods. This study revealed that the zooplankton productivity was found to be maximum during summer season, followed by pre-monsoon, post-monsoon and monsoon. The population of zooplankton was positively correlated with various physico-chemical parameters, such as water temperature, pH, salinity, dissolved oxygen, total dissolves solids and electrical conductivity of the lake water. Regarding species diversity, no considerable degree of differences was seen in the diversity indices values of each zooplankton group in different season, as all the species was recorded in all the four seasons. However, some degree of difference was seen in the respective index value between different zooplankton groups in each season, because the number of species in each group was varies. As appreciable number of zooplankton species diversity was seen in this lake there is hope for its utilization for inland aquaculture of fishes and prawns, if it is properly managed.