Importance of sewage treatment ponds for water-birds in semi-arid zone of Gujarat, India

Abstract

Khodiyar sewage pond located in Anand district of Gujarat state in India was visited during each winter from 1988 to 2004 and every month from June 2002 to June 2004 to understand utilization of pond by waterbirds. The birds were observed by using binoculars (10X50) and a spotting scope (20X80). Species richness, Shannon Wiener Index (H’) and Evenness (E) were calculated for each month. Monthly data was divided into three seasons viz. monsoon, winter and summer. Physicochemical parameters such depth, temperature, pH and dissolved Oxygen (DO) were measured. Total 66 species of waterbirds belonging to 17 families and 11 orders were recorded. There was no significant difference in the Shannon-Wiener Index and evenness between the three seasons. Total density (F2, 20 27.57, P < 0.0001) and species richness (F2, 20 39.61, P < 0.0001) of water birds of different seasons differed significantly due to influx of migratory birds during winter. Species richness and density of water birds were not significantly correlated with the physicochemical parameters of the pond. The Khodiyar pond was found to be important for waterbirds conservation.