The aquatic ecosystems are extremely important to mankind as they have several uses including drinking water supply, irrigation, navigation, recreation etc. and also serve as sources of organic productivity. Water may be stagnant in the form of lakes, ponds, pools etc. Lakes are naturally formed due to depressions on the earth surface that become filled with water and have diverse geological origin. High altitudes lakes are not exposed so much to pollution sites and are extremely oligotrophic in nature. The ever increasing populations and rapid industrial growth in the present as well as tourist influx are major contributors in influencing the physico-chemical properties of most water bodies. The primary production in high altitude lakes is low due to harsh abiotic conditions.
The land of Uttarakhand comprising the Garhwal and Kumaon regions has many charms to offer. It has abounding mountains, rivers, forests, flora and fauna. The Garhwal Himalayas in addition to a complex network of fluvial ecosystem are blessed with a large number of beautiful lakes. Beside this, many lakes are situated in the lap of the region that adds to the grandeur and scenic beauty of the region.
Garhwal Himalayan lakes occupy a significant place in Hindu culture being of both religious and mythological value. Saints and people from all religions trek long distances to worship such holy lakes. But a drastic change in water quality has been seen recently in these lakes due to increased anthropogenic interference. The water level has also receded rapidly in these lakes. These ecosystems are influenced by the activities outside and by inadequacy of support and participation of local people in their conservation.
The Nachiketa Tal- All around it is an aura of peace and purity. The lake has captivating surroundings with forests all around. Here, the unholy are said to become holy and the holy, holier still. The lake is located between latitude N 300 27’ and longitude E 710 72’ with the altitude of 2680m high above sea level to northeast of Uttarkashi district of Uttarakhand and about 200m long and 30 m wide at its broadest points having the depth of 7 m. It is elliptical in shape and medium in size and has no discernible inlet as well as outlet. Natural drains are the only source of water for the lake which are managed by the luxuriant vegetation around the lake. It is quite possible that the lake is a depression in a possible fissured zone which may open into the under water springs feeding the lake continuously.
The lacustrine ecosystem of Nachiketa Tal is an important natural resource and particularly valued for its aesthetic and recreational value. Vegetation cover that provides an enchanting view to the nature lovers; surrounding the lake and dominating species are Quercus leucotrichophora, Q. semicarpifolia, Q. floribunda, Rhododendron arboreum, Myrica esculenta, Lyonia ovalifolia, Taxus baccata, Alnus nepalensis at top canopy while the ground vegetation is dominated with Rubus ellpticus, Berbaris aristata, B. asiatica, B. lyceum with several medicinal herbs viz.Potentila fulgens, Viola betonicifolia,Bergenia ciliata, Rosa brunonii, Ajuga bracteosa, Ocimum gratissimum etc.
Ecosystem management is an emerging ecological philosophy and approach to solving the problem of environmental degradation. It is a goal driven approach to restore and sustain healthy ecosystems and their functions and values. Steps should be taken to gain better insight into the functioning of such kind of unique ecosystems and conserve them for posterity. Professionals in limnology and water management help to bring understanding and extent to all concerns that water problems focus on both the quality and quantity of freshwater resources. Land degradation is one of the major problems in the management of high Himalayan lakes. During Monsoon when rain strikes, the zonal turbidity increases which is the result of sediments addition from sites. Various forms of environmental perturbations affect quantity and quality of inland water due to increasing run-off, erosion and sedimentation. These are some of the major factors responsible for the degradation of lentic environment of Nachiketa Tal.
Degradation of this aquatic ecosystem is one of the most pressing issues of the environmental concern of the present time. Lack of scientific interest and knowledge has led to the destructive use and faulty management of this ecosystem. It is quite obvious that if a system fails to function, the consequences can often be unpleasant, expensive and irreversible. “Lakes” depending on their spatial position, size and biota, perform a number of ecological functions, and accordingly have different value for human beings. Unlike the lakes of other parts of the world, high altitudes lakes have different kinds of problems. Most of these lakes are acidic and ultra-oligotrophic to oligotrophic in nature. These lakes are very sensitive to the changes caused by anthropogenic activities. The major factors responsible for the degradation of the lacustrine ecosystem of the Nachiketa Tal are as follows:
Although the lake does not have any point source of anthropogenic pollution but it is largely affected by the activities of tourists. Every year, the lake is visited by a number of school/college students during autumn and summer breaks. These groups stay at the lake for two to three days. They throw solid waste and plastic bags here and there in the periphery of the lake. Digging of adjacent catchment for installation of tents not only accelerates the soil erosion but also damages the aesthetic beauty of the lake.
Meddling of local people
Problems multiply when local people interfere in the catchment of the lake. Removal of vegetation cover from the catchment area of lakes produces ecological problems such as reduction of allochothonous material available to lakes and loss of a “filter system” for material and suspended particles. Disappearance of forest deprives waterfowl and other wildlife of food and shelter. Thus the function of a “buffer zone” between terrestrial system and lake is impaired. Increased siltation of water is another consequence of deforestation. The front cover of the lake experiences frequent interferences by local people to meet their demands of fuel and fodder. It has severe repercussions; it does not only destroy the old plants but also hampers the growth of young saplings and seedlings at the forest floor.
There is large congregation of people around some of the lakes in Garhwal for fulfilling the religious faith. On the day of Baishakhi, thousands of people from Garhwal used to assemble at the bank of Tal (lake) every year and take holy bath in lake water to perform religious rituals.
Scope for management and development
Although the lake does not have any defined source of anthropogenic pollution yet it is largely affected by the tourist activities and interference by the local people in the catchment of the lake. Considering various aspects of degradations following sets of suggestions are recommended for the sustainable management and development of the lake:
Scientific agencies/NGOs should be appointed for regular updating of information on water quality and ecosystem functioning issues.
The information on the values and contribution of lake towards sustainable development should also be collected.
In order to restore ecosystem services, local people should undertake efforts to promote the growth of new vegetation cover, reduce litter and other vegetative material on the floor which ultimately detiorates the rate of humus formation, it decreased the pH of the lake making it more acidic during late summer. Therefore, a comprehensive plan should be developed to bring the catchments of the lake under good perennial vegetative cover.
The inflow of sediments from this zone must be controlled by mulching the zone under a good cover of grass or by some mechanical measures. This will help in maintaining the quality of ecosystem of the lake for a long run.
The region is well known for tourism throughout the country and also abroad for its unexploited natural beauty, religious and mythological values. The Nachiketa Tal, one of the largest lakes of Garhwal Himalaya is most attractive, situated centrally in Garhwal Himalayan zone is under the management of forest department. Scientific management can turn these aquatic ecosystems into a tourist resort for attracting the nature lovers, wildlife –watchers, trekkers and anglers which will ultimately strengthen the state economy.
Reference: Pooja Uniyal Bhatt and Sunil Prasad, Department of Forestry, HNB Garhwal University, Srinagar Garhwal, Uttarakhand
Shailesh is post graduate in Environment Management from Forest Research Institute (FRI) University, Dehradun, India. Presently he is working in the areas of Environmental and Renewable Energy Advisory Services. He has started GreenCleanGuide.com during his college days.