- Agricultural practices and human settlements are leading to the decline of Manipur’s iconic Loktak Lake and its floating islands (phumdis), the last natural refuge of the endangered Sangai deer, reports a study.
- Changes in land use patterns may be linked to the construction of the Ithai barrage in 1979 for the Loktak Hydroelectric Project.
- There is a need for regular monitoring and implementing proper land use practices in and around the lake, to restore the degraded ecosystem plagued by pollution and an altered aquatic regime.
Manipur’s iconic Loktak Lake and its floating islands (phumdis), the last natural refuge of the endangered Sangai deer or the Indian Eld’s deer (Rucervus eldii eldii), are losing ground to mushrooming agricultural practices and human settlements, reports a study.
These changes in land use patterns may be linked to the construction of the Ithai barrage in 1979 at Ithai (downstream of Manipur river) for the Loktak Hydroelectric Project, the study notes.
The 246.72 square km lake, slightly smaller than the Caribbean islands of St. Kitts and Nevis, is a Ramsar Wetland of International Importance cradled in the floodplain of the Manipur river. About an hour and a half from Manipur’s capital Imphal, the lake and the resident Sangais are the principal attractions for travellers.
It is also northeast India’s largest freshwater lake and like a jewel in a crown, it is positioned almost centrally in the state of Manipur that shares borders with Myanmar (earlier known as Burma). Teeming with a diverse range of flora and fauna, the lake ecosystem lies in the Indo-Burma Biodiversity Hotspot.
A source of water for hydropower generation, irrigation and drinking water supply, the lake has become a hotbed of tourism and related developmental activities. And since time immemorial, the ancient water body has nurtured fishing and agriculture shaping, the region’s socio-economy.
According to the folklore of the Meitei, Manipur’s culturally dominant indigenous group, the lake was home to India’s very own Loch Ness monster, a mythical horned python called Poubi Lai.
Now, the wetland system is in the crosshairs of development and tradition with environmental conflicts underpinned by changes largely ascribed to the 40-year old barrage.
Using satellite data from 1977 to 2015 (from the pre-barrage to post-barrage period), scientists have mapped the decline of the phumdis that are critical in supporting the weight of these animals (also called dancing deer for their dainty gait) as they negotiate their way through the floating islands.
“We have observed a loss in phumdi area that is equivalent to more than double the increase in agricultural areas in a span of 38 years from 1977 to 2015 (from the pre-barrage to post-barrage period),” Rajiv Kangabam, from Assam Agricultural University and lead author of the study, told Mongabay-India.
The floating national park and the dancing deer are under threat. Video by Kartik Chandramouli/Mongabay.
Deer that dance across the phumdis
Protecting the wetlands ecosystem with the phumdis is crucial to conserve the Sangais, because the beautiful animals are concentrated in the 40 square km Keibul Lamjao National Park (KLNP), that is actually a floating meadow or island (phumdi) in the southern rim of the lake. It is considered as the only floating reserve in the world.
Only 260 dancing deer remain, as per the forest department while wildlife biologists from Wildlife Institute of India stack the figure at less than 100 adult breeding individuals. The endemic Sangai was believed to have gone extinct until a remnant population was discovered in the early 1950s.
Ubiquitous in folk art and lore, the Sangai is also the state animal of Manipur. The emblematic species also lends its name to the annual festivities (the Sangai festival) organised by the state government each year in November. The KLNP was created in 1977 to conserve the last of the Sangais and the lake biodiversity within the phumdi ecosystem.
Tourists who opt for boat rides in the waterways within the phumdis can step on them and feel them pulsate.
This is because phumdis are floating mats of soil, plants and organic matter at various stages of decomposition all naturally bundled together. Part submerged, part floating they are the elements that impart uniqueness to the Loktak ecosystem. Two-thirds of the saucer-shaped lake is dotted by these floating meadows.
The study highlights the loss of floating islands from the southern and northern part of Loktak as a “major concern” that will lead to the “destruction of the only floating national park in the world.” It indicates an increase in open water area, human population and agricultural area.
In the study, in terms of land use changes, the highest loss is reported in phumdis with thin vegetation (49.38 square km) followed by phumdis with thick vegetation (around nine square km), while there was an overall increase in open water bodies (27 square km), agricultural areas (25.33 square km) and settlement (5.75 square km).
Kangabam said the rapid growth in human settlements is associated with the submergence of vast swathes of agricultural lands, a fall out of the construction of the Ithai barrage.
“It was estimated that 20,000 ha (83,000 ha unofficial) of arable land was submerged resulting in the loss of employment of the local people. This led to increase in human pressure on the lake resources leading to increase in human settlement and a high demand for fish,” he said.
Loktak lake over the years. Slide to view the disappearing phumdis.
The authors also identified the need for the proper implementation of the Manipur Loktak Lake (Protection) Act, 2006 in order to guide the increasing anthropogenic activities in the lake area, to protect the Loktak through sustainable management and conservation of the rich biodiversity.
The analysis also underscored the need for regular monitoring and implementing proper land use practices in and around the lake in order to restore the degraded ecosystem plagued by pollution and an altered aquatic regime.
“There is a need to balance ecological protection and human needs. Without provision of alternative livelihood options, the human pressure on the lake will go up and this will be disastrous for the lake,” Kangabam said.
Oinam Rajen of All Loktak Lake Areas Fishermen’s Union Manipur (ALLAFUM) agreed with the inference.
“At least two lakh people are directly dependant on the lake for fishing. The demand for fish has increased. However, adequate fish is not available in the lake. This is mainly because the migratory fish from Chindwin-Irrawaddy river system to Manipur river system have declined steadily after the barrage came up. Human settlements have gone up and so has paddy cultivation,” said Oinam Rajen.
However, Rajen demanded scrapping of the 2006 Act.
“This is compounded by the fact that we are prevented from carrying traditional fishing equipment inside the lake as per provisions of the Act. Rights of fisherfolk are being curtailed in the name of conservation. We are importing fish from other states to make up for the deficiency,” rued Rajen.
Around nine percent of the total population of Manipur (0.2 million/2.2 lakh) dwell in 12 towns and 52 settlements placed in and around the lake, earlier dubbed a “lifeline” of the people of Manipur.
By absorbing the annual monsoon flood, the lake plays an important role in flood control and conserves water through the dry months.
The cultivation of paddy is the traditional practice in the phumdis, explained Kangabam, adding that it also the source of livelihood for the rural fisherman who inhabit the surrounding villages and also on the phumdis in traditional huts called “khangpoks.” Some paddy varieties can also grow in the submerged conditions of the phumdis.
Resembling green rings, man-made aquaculture ponds called “athaphums”, created by segregating portions of phumdis, are used for fishing. Fresh and fermented fish hold sway in the Manipuri diet.
The operationalisation of the Ithai barrage in 1983 for hydroelectric power generation and irrigation purposes, without proper planning, has been linked to a multitude of problems shrouding the once pristine lake.
In 1986, the Manipur government constituted Loktak Development Authority (LDA) to check the deteriorating condition of the lake and to bring about improvement of the lake ecosystem along with development in the field of fisheries, agriculture and tourism while conserving the catchment area.
Decline in fish resources affecting the livelihoods of the fisher communities, enhanced soil erosion leading to wetland sedimentation due to shifting cultivation and loss of vegetal cover in the catchment area, reduction in water holding capacity of wetlands as a consequence of siltation, encroachments and prolific growth of aquatic vegetation are some of the problems listed by the LDA on its website.
Gradual degradation of the lake and associated swamplands sparked international concern with the water body being included in the Montreux Record in 1993 as a result of problems such as “deforestation in the catchment area, infestation of water hyacinth, and pollution.”
Serving as the receptacle for about 30 rivers and streams, the lake has turned into a dumping ground for the untreated waste that is drained into it from these water bodies, including the highly polluted Nambul and Nambol rivers. The barrage is the only outlet for the rivers.
“In addition, the establishment of the Ithai barrage has disrupted the normal flushing pattern of the lake and also interfered with the natural process of synthesis and breakdown of the phumdis,” Kangabam said, referring to the unique sink and swim cycle of the floating islands critical to its growth and function.
Earlier, during the monsoons when the water level would go up, the phumdis would float on the lake surface and in the dry season they would sink to the lake bed and sponge off the nutrients there which were essential for the growth of vegetation.
When the rain came, the islands with nutrient-laced plant roots would float again. However, the Ithai barrage (10.7 metres high and 58.8 metres long) for the Loktak hydroelectric project has resulted in “permanent flooding” of the lake.
“Now, there is continuous storage of water in the park area as a result of the barrage and islands float throughout the year even during the winter season. This has prevented nutrient uptake by the islands, thereby reducing their thickness,” said Kangabam.
Kangabam and co-authors of the study have flagged this reduction in thickness as a “major concern” for the Sangai.
Oinam also pointed out that water pollution and resulting enrichment of nutrients, fuelled the growth of the aquatic weeds and led to the proliferation of the phumdis at a certain point in time after the barrage came up.
“Before the construction of the Ithai barrage, the phumdis would proliferate and during the rainy season, they would be discharged from the lake to the Manipur river thereby maintaining the population. But the construction of Ithai barrage blocked the passage and changed the flushing mechanism,” Kangabam said.
Oinam claims it was due to the efforts of the fishing communities that the phumdis were prevented from pervading the entire lake.
“We took it upon ourselves to clear off the excess phumdis. Since time immemorial, the fishing communities have maintained the lake,” Rajen said.
The subsequent decrease of phumdis from the central part of the lake is due to the removal of the biomass (by authorities) to maintain the water quality, said Kangabam.
“The proliferation of phumdis has decreased from the central part. In the northern and southern part the phumdis remain as it is. But human activities have increased in those parts so overall phumdi area has gone down,” Kangabam said.
Bioprospecting for bacteria in the phumdis
Saving the lake is also advantageous for bioprospecting of potential bacteria for their use in agriculture as plant growth promoters (biofertilisers).
Recently, a team of scientists isolated 26 bacterial strains from the phumdi sediment and lake water, which they say, can be used in sustainable agriculture.
These isolates from Loktak Lake have the potential to be used for the production of industrially important enzymes and in agriculture as plant growth promoters (such as siderophores, indole acetic acid or IAA), said Milind Mohan Naik of Goa University’s department of microbiology in a study.
For example, among the 26 Loktak bacterial isolates, Enterobacter tabaci strain KSA9 is found to produce siderophore, IAA, involved in nitrogen fixation, phosphate solubilisation and ammonia production.
The presence of plant growth promoting microorganisms was expected from phumdi sediment, due to the fact that the local people use phumdi sediment as a biofertiliser in agriculture. It exhibits good plant growth promotion that may be attributed to the presence of bacteria. The bacterial diversity is facing threats due to the overall disturbance of ecosystem.
Beset with dwindling water quality and ecosystem, the lake has been battleground between the LDA and a section of fishermen with both parties trading charges on who is responsible for destroying the wetlands.
The fishermen’s union claims that in the name of cleaning the lake, the LDA is damaging lake while the authority alleges the fishermen and their floating huts are the ones harming the lake.
“Enforcing the Manipur Loktak Lake (Protection) Act, the government (under the then Chief Minister Okram Ibobi Singh) began to clear the lake of human settlements in 2011. There were 1100 huts built on the phumdis. 777 huts were burnt and hundreds of families and more were evicted since then. The fisherfolk were dubbed ‘occupiers’,” Rajen said.
According to activist and researcher Ram Wangkheirakpam of Indigenous Perspectives, the Loktak Protection Act requires a “proper review” for the fact that it does not conform to the requirement of the Ramsar Convention nor to the more recent National Wetland Convention Rules 2017.
“The Act does not cover the whole of the lake. It excludes the water sports area at Takmu that they have carved out as also the Keibul Lamjao National Park. There are two resorts,and two hotels coming up, they are also trying to evict some 450 families for the resort in the name of tourism promotion in the state,” the activist said, adding that Loktak Development Authority is a failed institution and requires a comprehensive revamping of its constitution and composition.
“It is clear that this Act has been twisted to fit in certain kind of activities while putting traditional users as victims. Traditional livelihood options have somehow been sidelined while non-traditional activities are being promoted. The local community must be included in conserving this wetland,” Wangkheirakpam said.
Kangabam, R. D., Selvaraj, M., & Govindaraju, M. (2018). Spatio-temporal analysis of floating islands and their behavioral changes in Loktak Lake with respect to biodiversity using remote sensing and GIS techniques. Environmental monitoring and assessment, 190(3), 118.
Salkar, K., Gadgil, V., Dubey, S. K., Naik, M. M., & Pandey, R. R. (2018). Largest freshwater lake ‘Loktak’ in Manipur needs urgent conservation. Indian Academy of Sciences.
Banner image: Fishing in the Loktak lake. Photo by Rajiv Kangabam.