IMPACT OF PHUMDI PROLIFERATION ON THE RESIDENT BIRDS OF LOKTAK LAKE, MANIPUR (INDIA)

摘要

Loktak Lake is a Ramsar site in Manipur State and is the largest natural freshwater lake in the northeastern region of India. The lake is oval in shape with a length and width of 26 km and 13 km respectively, covering an area of about 289 km~2 at an altitude of 768 m above sea level. The depth of the lake varies from 0.5 to 4.58 m, with an average depth recorded at 2.7m. The characteristic feature of this lake is the presence of floating islands covered with vegetation, locally known as phumdi. These floating islands that occur in all sizes and thicknesses are heterogeneous masses of soil, vegetation and organic matter in various stages of decomposition. They float on the lake with about one-fifth of their thickness above water and the rest below the surface. Though a eutropic lake, Loktak maintained a somewhat healthy ecosystem before the commissioning of the controversial Loktak Electric Project in 1983. This internationally important and biologically rich lake is a unique wintering ground for various migratory waterfowl and the permanent home to many resident waterbirds.