51-Impact of migratory birds on the wetland ecosystem with special reference to the nutrient load and primary productivity of an urban wetland - A Preliminary Study

Abstract

Wetland ecosystems are considered as a closed ecosystem in which different varieties of life grow and decomposes. It is a transitional area characteristic of terrestrial and aquatic ecosystems. The productivity and characteristic of a wetland constantly are in a status of flux because of dynamic biotic and abiotic factors. The type and quantity of nutrients that enter and exit wetlands through external factors vary among location, seasons and years. The migratory birds and animals are one of such factors responsible to change the nutritional status and productivity of wetlands. The present study is focused on the nutrient load on the wetlands due to the migratory birds. Mainly three chief nutrients viz. phosphorus, nitrogen and sulfur were estimated during pre migratory, migratory and post migratory seasons by collecting the water samples. Primary productivity of these water samples were also estimated to know the impact of nutrient load on the primary productivity and other functions of a wetland ecosystem. The data were analyzed through student's't' test and correlation analysis to know the significances of nutrient loading during the migratory season. The study shows that the nutrient like phosphorus increases with increase in the migratory bird number and are positively correlated with the primary productivity. This preliminary study also suggests that the life forms in an urban wetland, human interference and the migratory bird communities are collectively affect the self sustainity of a wetland ecosystem.