Trophic State Index of Rankala Lake, Kolhapur (Mh) India

Abstract

Rankala Lake is situated in the heart of Kolhapur city of Maharashtra, India. Five samples are collected from five different locations of Rankala Lake to assess tropic state index (I'S!) of the lake. A sample of water is taken from just below the surface water in the morning time. The parameters like Secchi di.sc Transparency, Dissolved Oxygen (DO), Most Probable Number (MPN), phytoplankton, Net Primary Productivity, Gross Primary Productivity, Chlorophyll-A, Algal Biomass, Phosphates and Pesticide content parameters are studied. The correlations between Trophic Index (I'J), chlorophyll (Chl), phosphorus (P), Secchi Depth (SD) are derived and use Carlson's Trophic Indices to arrive at the tropic state Index of the lake. The phytoplankton types are observed under trinocular light microscope while genera observed are classified and listed according to Palmer (] 969). The primary organic production is studied by 'Dark' and 'Light ' bottle method and by extraction of chlorophyll. As per these guidelines of Carlson 's TS/, Rankala lake (I'S! = 80.84) can be classified as Hypereutrophic water body and are totally unfit for drinking purpose due to it polluted excessively. This is mainly due to excessive discharge of untreated sewage, agricultural runoff, industrial wastes and other wastes which a. Fleets the aquatic ecosystem of the Rankle Lake.