Effect of polluted water on Danio rerio (Zebrafish) as a vertebrate model: A case study of Ibalur Lake, Bangalore, India

Abstract

Lake ecosystems are degraded with the increase in urbanization and anthro-pogenic activities. A study was taken up to analyze the effects of water quality of Ibalur Lake, Bangalore, India. The physico- chemical parameters and bacteriological examination of lake water was done for a period of 3 months from December 2013 – February 2014. The values recorded for Dissolved oxygen (DO), Biological oxygen demand (BOD) and Chemical oxygen demand (COD) were found to be zero. The average values recorded for parameters like calcium, total alkalinity, hardness were 231mg/L, 197mg/L and 587.1 mg/L respectively which were found exceeding the WHO standards set for drinking water; Parameters like Magnesium, Sodium, Chlorides, Sulphates had an average value of 140, 18.4, 59.5, 15 expressed in mg/L, which were within the WHO standards. Coliform count customized using the standard Most Probable Number (MPN) test reported a very high bacterial activity and proved the lake water is non-potable. Analysis carried out to determine the effects of pollutants on the vertebrate system (zebra fish) showed that the polluted waters of the lake have deleterious effects on zebra fish. With these observations it can be concluded that the pollutants of the lake can have detrimental impact on the biotic components.