Fragmentation of Ecosystem in Loktak Lake

By Winson Kipgen *

Loktak Lake - Pix by Sushil Khomdram

Introduction :

Loktak Lake is the largest fresh water lake in North Eastern India. It is aslo the only floating lake in the world due to its floating wets/Biomass. The Loktak has an area of 35 Km in length and 13 Km in breath with minimum depth of 4.7 mtr. and 2.9 mtr. respectively.

Loktak is a home for hundreds of birds, animals and microbes. It is also the only habited for one of the most endangered edi's species ie Serves Edi edi or Sangai. The Loktak Hydro Power Project (LHPP) which was commissioned in the year 1985/86 over the Manipur river with Loktak lake forming the head waters to provide regulated storage for power Generation and generates Power of 105 Mega Watt that supply to whole North Eastern States.

Due to the construction of the Ithai Barrage for the Hydro Power Generation the vital Ecosystem had been affected resulting to declination of plant Species, animals species and many other living organisms in the lake and its surroundings. Thus, it leads to disturbances in an arround the catchment area and Social crisis arose rapidly and now it became a big political issue within the political parties.

Biodiversity :

A rich biodiversity with hetrogenity has been recorded during a scientific survey carried out between January, 2000 and December 2002 in different habitat patches of the lake. The lake's rich biodiversity comprises 233 species of equatic macrophytes of emergent free floating and rooted floating leaf types 116 species of birds and 425 species of animals.

The important vegetation of the Phumdis recorded are Oryza Sativa, Zizania talifolia, Sccharum latifolium etc the important vegetation of the rooted plants comprises Nelumbo nucifera, Trapa nutans, Euryale Ferox, Nymphae alba etc.

Out of 425 species of animals 249 are vertibrates and 176 are invertibrate. The animals recorded includes bears Rhesus Monkeys, Hoolock gibbon, Maccaque Marble cats, Temmiek golden cats wild bears, dancing deer etc. The fish yeild from the lake is reported to be about 1500 tons every year.

Now varieties of fishes are also introduced into the lake, the varieties include Grass Carp, Silver Carp and many other varieties of fishes like pengba are also introduced by the State fishery Department. And out of 116 species of birds 21 species are migratory waterfools which includes diving ducks and scyberian cravess etc.

Major factors which cause fragmentation of Ecosystem in Loktak lake and its impacts

(1) Blockage/stoppage of the Natural flow of water due to construction of Ithai Barrage for the Hydro Power Generation.

(2) The nutrients from catchment area and domestic sewage from Imphal City carried by the Nambul River are discharged directly into the lake.

(3) Full Reserviour level (FRL) leads to decrease the thickness of Phumdis in the Keibul National Park thereby threatening the Survival of Sangai deer and interference in the migration of fishes from chindwin Irawadi River resulting in declination of the fish population and its composition into the lake.

(4) Excessive use of Chemical Fetilizers by the farmers in an arround the catchment area.

(5) Deforestation and Shifting cultivation in the hilly area had lead to soil errosions.

Impacts :

(1) Stoppage of the Natural flow of water and the nutrients from catchment area and domestic sewage from Imphal City had badly affected the quality of the lake's water thus it enhance the growth of water hycinth an Phumdis/Biomass. Thus it covered the surface of the lake in a large area. Therefore, it blocked the sunlight and circulation of atmospheric oxygen into the water, thus the fishes and other living organisms inside the water had been severely threatned.

(2) Due to repeat proliferation of Biomass in a large area the population of migratory birds or migratory waterfawls had been declining rastically.

(3) The population of a number of economic plants such as sacchrum Species, Setaria pumila, Alpinia nigra, Hedychium Spicatum and the major food plants like the Zizania Latifolia carex species, coix species, Narenga has decrease resulting in starvation condition for the endangered Sangai deer. With the Phumdis becoming thinner the hoops of the limbs of Sangai get stuck in the marsh and result in their drowning.

(4) The Ithai Barrage had illy affected the people who are residing in an arround the catchment area mostly the people of Thanga, Karang area as their livelihood fully depend upon the lake and its resources.

(5) The polluted water due to excessive use of chemical fertilizers by farmers had severely threatened to the lake's environment and its surroundings many insects-friendly microbes and even a varieties of fishes had died out, thus resulting in affecting the vital ecosystem of the lake.

(6) Deforestation and shifting cultivation in the catchment area have accelerated the process of soil errosion. The annual silt flow into the lake is estimated to be 3,36,325 tons. Thus, it over flooded the lake's banks ands surrounding hereby it submerged a variety of plants species and affected in the food chain of animals insects and other living organisms.

Remedies to Solve the Problems of Fragmentation of Ecosystem are :

(1) The Nambul River carries Sewage of nutrients of Imphal town into the lake which result in prolific growth of Phumdis and deteriorate water quality due to unproper drainage system and dumping sites in the Imphal town. This is an urban problems and there is urgent need to treat and control this aspect even it it is expensive.

(2) To tackle the problems severals programmes like awareness programmes, campaigns about management of sewage among the people not only in arround like Imphal town but to whole the people of Manipur since the responsibility lies in the hands of each and everyone who live in the State.

(3) Dust Bins and proper dumping sites at marketing places should be provided compulsarily by State Government in order to minimise dumping of sewage into the Nambul River and its banks.

(4) To reduce soil errosion and sedimentation of the lake micro-watersheds in the catchment area treament plan should be constructed and enlarged.

(5) Action plans that are economically viable and technically feasible resulting in livelihood enhancement such as evolving an attractive settlement plans for the Phumdis dwellers backed by remunerative livelihood programmes should be implemented.

(6) Education and awareness programmes to the people who are residing in an arround the catchment area should be organised periodically and usage of chemical fertilizers, pesticides should be baned and organic farming should be emphasis and encourage to farmers.

(7) Education and awarness programmes especially to hilly peoples regarding shifting cultivation and deforestation and its empacts in our environment should be organised and the State Govt should introduce an alternative means of livelihood like Handicrafts and many other mode of occupation for these peoples.

(8) Lastly the concerned authority of the NHPC should take upon their responsibility seriously. They should periodically open the Barrage and close it periodically so that the degraded ecosystem of the lake can be recovered once a while. If the main problems are not solved, only by cutting out the Phumdis won't work so, the NHPC and State Govt should thus give full concern on these issues.

Conclusion :

If we are not aware of our activities towards our surrounding and if we are still in a safety blinded then, sure we may lost the largest fresh water lake in North East India and if we are not concerned about its affected ecosystem and its situation then the only edi's species of the world will extinct pitifully from our land.

In order to safeguard Loktak and its surrounding, now is the right time. Let's joined hands together to safe our Loktak and let's start thinking for our property but not our own property so that we may enjoy in future. The responsibility of each and every one of us in this regard is very important for better tomorrow.