Phumdi

Although phumdi vegetation has existed for centuries, it was not until 1886 that the Manipur Gazetteer recorded that wetlands with floating islands were used by inhabitants for fishing. Athapums, artificial circular phumdis, which were built by the villagers as enclosures for fish farming, are present on the lake, and this aquaculture has caused further proliferation of the phumdis. == Ecological composition ==

The floating mass of matted vegetation, organic debris, and soil that constitutes a phumdi has a thickness that varies from a few centimetres to two metres. Its humus is black in colour and porous, with a spongy texture. Only 20% of a phumdi's thickness floats above the water surface; the other 80% remains submerged. However, the contemporary situation, with high water levels in the lake throughout the year, has meant that the process of 'feeding' on lake–bottom nutrients has been seriously disturbed, resulting in a loss of biomass and a thinning of the islands each year. The Diversity indices of the plant species were recorded; they were a richness of 48, diversity of 0.29 and evenness of 0.47 in summer. In winter, the respective figures were 81, 0.17 and 0.52. Species richness was found to be different in 48 samples of thin phumdis, 53 samples of thick phumdis and 14 samples on hard ground. Apart from the brow-antlered deer, which is the flagship species of the park, other fauna found in the park are mammals, reptiles, and migratory and resident avifauna species. Mammal species consist of hog deer (C. porcinus), wild boar (Sus scrota), large Indian civets (Viverra civetta, Viverricula indica), common otter (Lutra lutra), fox, jungle cat, Asian golden cat, bay bamboo rat, musk shrew, common shrew, flying fox, and sambar (Cervus unicolor). Reptile species found in the park are the keel back tortoise, viper, krait, cobra, water cobra, banded krait (Bungarus fasciatus), Asian rat snake (beauty rat snake), Russels’ viper (Daboia), checkered garter snake, python and common lizard (viviparous lizard). Python molurus is an endangered species found in the park. Prominent bird species seen in the park are both migratory and resident avifauna species. Some of the avifauna are the East Himalayan pied kingfisher, black kite, lesser sky-lark, northern hill myna, Indian pied myna, North Indian black drongos, lesser eastern jungle crow, yellow headed wagtail, spotbill duck, blue-winged teal, ruddy shell duck, hooded crane, Burmese sarus crane, Indian white-breasted waterhen and crimson-breasted pied woodpecker. ==Environmental issues==

The proliferation of phumdis, coupled with severe infestation of the lake by water hyacinth, has substantially impeded water circulation and caused an increase in siltation and deposit of pollutants in the lake ecosystem. Further, pesticides and insecticides are used for catching fish or as insect repellent. Processes of decay release toxic gases such as methane and hydrogen sulfide, and reduce dissolved oxygen. Recent reports indicate that locals are slicing the phumdis into sizeable pieces and towing them with canoes to sell to fish culture owners. low pH (normal range for Loktak Lake is 6.3 to 8.2) high CO2 and high Biochemical Oxygen Demand (BOD) but the water quality was good in the open water area. Assessment of the total nitrogen content of the macrophyte species of phumdis indicated that the following were present in descending order: Salvinia natans (1.8%), Zizania latifolia (1.6%), Capillipedium sp. (1.3%), Brachiaria mutica (1.2%), Cyperus brevifolius (1.2%), Echinochloa stagnina (1.0%), Phragmites karka (1.0%) and Hedychium coranarium (0.94%). The test results confirmed the fact that the phumdis were efficient in absorbing nutrients from the lake water. However, they deteriorated water quality due to reduced light penetration and accumulation of organic matter in the lake ecosystem. ==Management strategies==

A detailed study has been conducted by the Loktak Development Authority (LDA) in collaboration with Wetlands International–South Asia, supported by the India–Canada Environment Facility, implementing a project on Sustainable Development and Water Resources Management of the Loktak Lake. The project addresses the issues relating to water management, sustainable fisheries development, community participation and development, catchment area treatment and conservation of wildlife. In order to resolve the problem of the excessive growth of phumdis that affects the lake ecosystem and local community, a study sponsored by the India–Canada Environment Facility was undertaken by the Tata Energy Research Institute (TERI) to examine efficient ways of converting phumdis into briquettes as fodder and fuel pellets, which could be used to meet both energy demands within the region. Two options for the biomass conversion were studied. The first involved making briquettes of vegetative part of phumdis for use as fodder while the second proposed to pelletise the lower part of phumdis for use as fuel. The study observed that phumdis have nutritional potential as feed material due to its higher crude fibre and crude protein content, but the inorganic content in the root and mat zone was found to be unsuitable for the purpose. The second option of making briquettes from the upper vegetative portion of the phumdis by mixing 12% de-oiled rice bran was found to be feasible for using them as fodder. Other methods adopted by the Loktak Development Authority (LDA) to control phumdis and water hyacinth include introducing weevils for the biological control of water hyacinth, which was carried out in collaboration with the Horticulture Institute of Bangalore. Reports have shown this to be an effective method in controlling water hyacinth. In a recent workshop organized by the LDA on "Management of Phumdis" in the Loktak Lake, which involved presentations by locals, the emphasis was on the need to open the barrage for eight months per year (January, April and June–September) to clear the phumdis, control floods and wash away the silt and waste that had accumulated over time. The LDA is also implementing action plans that are economically viable and technically feasible which would result in livelihood enhancement such as evolving an attractive resettlement plan for the phumdi dwellers backed by remunerative livelihood programs and examine the introduction of fishing nets instead of Athapum, the circular shaped Phumdis floating in the lake, planted or cultured artificially for catching fish. ==References==