Loktak Lake Phumdi Floating Islands Bishnupur Manipur

Loktak Lake in Bishnupur district of Manipur is the largest freshwater lake in northeast India and one of the most ecologically unique water bodies in the world due to its famous phumdis — floating heterogeneous masses of vegetation, soil, and organic matter that cover approximately 40 percent of the lake surface. Phumdis form when sediment deposited by inflowing rivers accumulates around rooted macrophyte vegetation (especially Saccharum munja grass and Zizania latifolia), creating buoyant mats that can be 2 metres thick. Keibul Lamjao National Park — the only floating national park in the world — exists on the largest phumdi mass (about 40 square kilometres) and is the last natural habitat of the critically endangered Sangai deer (Cervus eldii eldii), Manipur's state animal, which lives entirely on the floating phumdi surface. Local fishermen (Meitei Pangal community) practice a unique fishing method called athaphum — constructing circular phumdi enclosures as fish traps and living seasonally on small hut platforms built directly on the phumdi floating mat. Loktak lake hydrology is threatened by the Ithai Barrage (1983) which raised water levels year-round, reducing the natural dry-season phumdi compaction that supports biodiversity. Ecological restoration programs funded by the Loktak Development Authority aim to restore natural water level fluctuation. The lake is a Ramsar Wetland of International Importance (listed 1990).