Some Aspects of Limnobiotic Profile of River Garga in Context of River Continuum Hypothesis

Abstract

newline A comprehensive study was done on Garga River of Bokaro Steel City in Jharkhand. Altogether twelve physico chemical parameters and diversity and density of phytoplankton and zooplankton were observed and analyzed for the study period of two years starting from September 2012 to August 2014.Each year was divided into four seasons viz. post-monsoon,winter, summer and monsoon. Four sampling stations namely G1, G2, G3 and G4 were selected along the entire stretch of the river.Sampling, preservation and analysis were done as per the standard prescribed methods. The results obtained were tested with statistical methods. A total of 23 taxa of phytoplankton and 21 taxa of zooplankton were recorded from all the four sampling stations during the entire study period. The comparative analysis of the data obtained clearly indicates that the river water is more polluted at sampling sites G2 and G3(which are situated among densely populated colonies) and less polluted at G1 and G4(which are away from human settlement). newlineMoreover it was found that there is a continuity in the flow of the river.There is no input of any tributary but the river gets the input of pollutants at various places. Various types of pollutants are changing the original nature of the river but as it moves from headwaters to mouth the original physical and chemical nature is regained through the process of self-purification.Planktons, both phytoplanktons and zooplanktons are more or less similar throughout the longitudinal gradient of the river. newlineThus it can be concluded that Garga river does not entirely follows the RCC but it explains that as it moves from headwaters to mouth,the physical variables change along the longitudinal gradient of the river and the biotic flora and fauna respond accordingly. newline