STUDY ON VERTEBRATE FAUNA, STATUS AND IMPACTS OF ENVIRONMENTAL POLLUTION ON WETLAND CHOTIARI RESERVOIR (SINDH)

Abstract

The present study was undertaken to document vertebrate fauna (richness and abundance of mammals, birds, reptiles and amphibians) at Chotiari Reservoir, to determine their status and to assess the impacts of anthropogenic factors, if any, on the reservoir and its vertebrate biodiversity. Chotiari Reservoir complex includes wetlands, which altogether, have been identified by Bird Life International as an Important Bird Area. Further, the complex fulfills certain criteria of Wetland of International Importance-Ramsar Site. A total of 203 vertebrate species belonging to 29 orders and 78 families were recorded from Chotiari Reservoir during 2006- 2010. These included 32 species mammals (14 medium and large sized mammals and 18 small mammals); 136 bird species (53 water birds, 48 passerine birds, 13 birds of prey and 22 miscellaneous birds); 32 species of reptiles (a single species of crocodile, 3 species of turtles, 15 species of snakes and 13 species of lizards) and 3 species of amphibians (1 toad and 2 frog species). As many as 136 bird species belonging to 19 orders and 48 families were recorded. Out of 136 birds, summer fauna and winter fauna constituted 69.11 % and 34.55 % respectively. It was found that alteration in the ecological conditions of the area after the construction of the Chotiari Reservoir had changed the avifauna species composition of the area. A total of 32 reptile species belonging to three orders and 14 families were recorded. These included three species of turtles (9.37%), 15 species of snakes (46.87%), 13 species of lizards (40.62 %) and one crocodilian species of (3.12 %). vMeans of total number of individuals recorded during 2006-2009 at 0.05 level were not significantly different indicating no change in the abundance of selected wildlife species during study period. It was, inferred, therefore that the wildlife diversity must have not been affected. However, distribution of threatned species of the area, such as Smooth-coated otter and Marsh Crocodile, might have been impacted. Based on present study data, the reservoir water was unpolluted, and reservoir is not connected with any source of industrial or municipal effluent. The concentration of heavy metals recorded during the study period as well as selected physico-chemical parameters were within safe limits and were below water quality standards of WHO (World Health Organization). Further, no evidence of the reservoir’s water contamination by industrial and agriculture runoff was recorded, for the reservoir did not have any industry in its surroundings nor could the water from the surrounding croplands enter in to the reservoir mainly because of two reasons. First, the land within the reservoir is not used for agriculture, and secondly drainage from the croplands is not carried in to the reservoir. However, changes in land use practices, habitat modification, hunting, unregulated fishing, overexploitation, community-wildlife conflict and trapping of wildlife species were identified as major issues affecting wildlife species composition and abundance.