Effects of Water Quality on Birds at Singanallur Lake, Coimbatore, Tamil Nadu, India

Abstract

Wetlands in India are seriously threatened by pollution due to rapid urbanization, industrial activities and unsustainable agricultural practices. The water quality of an urban lake is a key concern. A survey by line transects and point count method were conducted around Singanallur lake, Coimbatore, Tamil Nadu, India. The surface water samples were collected in sterile containers from the inlets and outlets of Singanallur lake between 2009 and 2011 and the physicochemical parameters, nutrient properties and heavy metals were analyzed using Atomic Absorption Spectroscopy. The pH value consistently appears to be above 7, indicating the alkaline nature of the water. Total suspended solids, total solids and total dissolved solids were exceeded the WHO permissible limit. Among the metals analyzed, copper was found to be the most prevalent at a concentration of 39.4 µg/ml. Stepwise linear regression (R = - 0.87) shows a strong negative relationship, suggesting that as the pollution load index (PLI) increases, the bird population correspondingly decreases. Specifically, the PLI was recorded at 4.5 in 2009 and had risen to 8.43 by 2011. The high PLI adversely affects the abundance and health of aquatic organisms, which serve as primary food sources for many bird species. The poor water quality of the surface water due to anthropogenic pressures in Singanallur lake gives out a serious warning, highlighting the urgent need to conserve the fragile ecosystem.