The entire Himalayan region is dotted with many beautiful lakes that are seen in areas of low elevation to high-altitude remote locations. Many of these lakes are freshwater ones, while some are brackish, with or without a constant feed from a source and an outflowing stream. These Himalayan lakes show varying eco-hydrology, as regards the chemical composition, bio-geochemistry, and mineral components. These differences arise from the variation in altitudes that affect the natural vegetation, climate, and erosion intensity of the lake locations. The outflowing streams from many of these lakes turn into mighty rivers as they flow down to the plains. The river Chandrabhaga is one such river, which has the waters of two smaller rivers, Chandra and Bhaga, arising from the vicinities of two high altitude Himalayan lakes, Chandra Tal and Suraj Tal.
The term high altitude wetlands (or HAW) technically means “areas of swamp, marsh, meadow, fen, peat-land or water bodies located at an altitude higher than 3,000 m, above mean sea level (amsl), whether natural or artificial, permanent or temporary, with water that is static or flowing, fresh, brackish or saline”. These lakes show extreme ecosystems, distinguished by mostly unfavourable climate and presence a layer of permafrost. These high-altitude lakes are fed by the glacial waters, springs, and precipitation (mostly snow), unlike the lower altitude lakes (such as Nainital or Bhimtal) that receive water from seasonal rains, via the water runoffs and mountain springs.
The Himalayan and the Tibetan plateau together form to be the world’s largest HAW, and the area holds many lakes of various shapes and sizes. Some of these lakes, such as Manas Sarovar (Tibet), Tso Moriri (Ladakh), and Manimaheshwar (Himachal Pradesh) are revered as teerth, and thousands of pilgrims visit them each year. The largest lake in the Himalayas is the Pangong Tso, which is situated in the newly formed Union Territory of Ladakh at an altitude of 4,350 m, is 134 km long and spread across the border between India and Tibet. All the important rivers in Southeast Asia such as the Brahmaputra, Ganga, Indus, Mekong, Yellow River, Yangtze, etc., originate from the HAWs of the Himalayan and the Tibetan Plateau. There are two HAWs in India designated as Ramsar sites: Tso Moriri (in the Union Territory of Ladakh) and Chandratal (in Himachal Pradesh).
The Higher Himalayan lakes in the Ladakh area have great ecological and socio-economic significances, and also play an important role in maintaining the biodiversity and wildlife habitats of those areas. The lakes have brackish waters with low biodiversity and are the breeding grounds for many migratory birds, such as the Bar-headed Goose and Black-necked Crane. Local communities (both nomadic and settled) are dependent on these lakes for their livelihood, as the pasture lands adjoining these wetlands serve as grazing grounds for the domesticated yaks, sheep, and horses.
The lake catchment is home to many endemic fauna species, such as the wild Yak, Musk deer, Red Panda, Tibetan Gazzle, Kiang (wild asses), Snow Leopard, Tibetan Antelope, etc. Many endemic and rare medicinal plants also grow in plenty in the lake catchment areas. The HAWs in Ladakh show extreme cold and dry climatic conditions, with very low oxygen levels, low air temperature, and high ultraviolet radiation. These areas have mostly shrubs and grasslands as vegetation cover, which are indigenous to the region.
Pangong Tso: The largest lake in the Himalaya is Pangong Tso. It is a long narrow lake (a chain of four naturally joined water bodies) with sparkling blue-green emerald waters that spread across the upper drainage basin of the Indus river. The lake has five streams that flow into its Indian part, while its western outlet flows into the Shyok river. Pangong lake has been declared as the High-Altitude Cold Desert National Park, as its waters support a great diversity of ichthyological life. It is also a breeding place for the migratory birds, while the surrounding catchments area supports many wildlife species, such as the friendly marmots and the Kiangs.
Tso Moriri also known as the Tsomoriri Wetland Conservation Reserve is a Ramsar site, and the deep blue waters of this beautiful lake vary from fresh to brackish based on the seasons. The lake is a breeding ground for the many waterfowls and bar-headed geese that are seen lazily floating over the shimmering waters. Earlier, Tsomoriri had a connection to the Sutlej river through an outlet, but the outlet later shrank making the lake got landlocked, owing to which the water remains saline or brackish most of the times.
The glacial waters from the snowy Changthang plateau form to be the major water source for this lake, while many mountain streams also feed water into it. While the flora growing in the marshes around the lake support the domesticated livestock, the alluvial plain near a stream feeding the lake from the western side (Korzan village) supports extensive farming.
Tso Kar lake is situated near Tso Moriri on its northwestern side. While it is believed the lake was once a freshwater body, it is now a saline water body with catchment area showing large deposits of salt and sand corrals. A part of the lake shows aquatic vegetation near the edges, which dry up during winter and form floating weed mats. Besides the many varieties of endemic flora, the lake also supports wild ass, Tibetan gazelles, marmots, common terns, brown-headed gull, Brahminy duck, and Bar-headed goose.
Travel tips: Ladakh is easily approached from Himachal Pradesh via the Baralacha La and Sarchu. It can also be approached from Jammu and Kashmir via the Leh-Srinagar highway. Entire Ladakh, including the lake areas, have low oxygen content, and it is advisable to visit a doctor prior to travelling to Ladakh, especially for those with high blood pressure and other health complications.