ALGAL ASSAY USED FOR THE DETERMINATION OF ORGANIC POLLUTION LEVEL IN FRESHWATER BODY AT TIRUVANNAMALAI, INDIA

摘要

Algal assay method successfully used as a tool to determine the organic pollution level in a freshwater pond in Tiruvannamalai, Tamil Nadu, India. Various physico-chemical factors like atmospheric and water temperature, pH, DO, free CO_2, magnesium, nitrate, phosphate, sodium were analysed for the water body. For estimation of pollution level, various algal indices such as Nygaard's trophic state indices and Palmer's pollution indices were used. The high value of Nygaard's combined indices (11.60) clearly indicated eutrophication of the water body. Palmer's generic index value (32) and species index values (32) also confirmed the organic pollution status of the site. Species diversity indices like species richness index (R) and Margalef's index(M) value (1.650) were observed in Bacillariophyta. This also confirmed the high level of pollution of the water body.