Feathers of Little Egret (<i>Egretta garzetta</i>) Fledglings as a Bio Monitoring Tool for Mercury, Arsenic, Cadmiumand Lead Pollution in Sri Lanka

Abstract

The objective of this study is to establish a baseline set of data for heavy metal contaminants in diverse ecosystems in Sri Lanka using bird feathers as a bio monitoring tool. During May to July 2014 heavy metal concentration (Hg, As, Cd and Pb) was assessed in bird feathers and regurgitated materials of Little Egrets (Egretta garzetta) and water collected within the foraging areas at five heronries from three districts of Sri Lanka. A significant variation of Hg and As (p<0.05) was observed. But such a significant variation was not observed for Cd (p>0.05). Only As concentration of regurgitated materials show significantly variation between sites (p<0.05) whereas no significant variation in Hg and Cd (p>0.05). In all sites, for all four metals there were some significant variations of metal concentrations in water. Pb was only detected in water and no more in feathers and regurgitated materials. The concentration of Hg, As, Cd and Pb were generally within the normal background level and mostly below the threshold level that may affect bird survival and reproduction. According to the results of the present study, feathers of Little Egret fledglings can be used as a bio-monitoring tool to measure the bio accumulation of Hg, As and Cd except Pb with combination of metal concentration of their regurgitated materials and water that was collected from the surroundings of heronries.