SRINAGAR: Manasbal Lake, one of Kashmir’s important freshwater ecosystems, is facing growing ecological pressure from agricultural runoff, sewage, tourism, stone quarrying and expanding human settlements, a recent scientific review has found.
According to the review published in Current World Environment states that increasing nutrient inputs from household waste, sewage and agricultural activities have contributed to eutrophication in the lake, affecting its water quality and aquatic life.
Researchers from the University of Kashmir’s Department of Zoology examined available studies on the lake’s hydrology, water quality, biodiversity and human-induced pressures, and called for comprehensive restoration and management measures.
Located in Ganderbal district, Manasbal is a deep freshwater lake with a maximum depth of about 13 metres. It covers approximately 280 hectares, including around 25 hectares of marshland, and receives water mainly from springs, precipitation and an irrigation channel.
The lake has no distinct natural inlet, while excess water drains through the Nunnyar Nalla and eventually reaches the Jhelum River.
The researchers noted that Manasbal’s catchment extends over about 22 square kilometres and comprises agricultural land, plantations, settlements and areas affected by quarrying.
“Human settlements, agricultural runoff, tourism, and stone quarrying” were identified among the major pressures affecting the lake.
According to the review, more than 31 per cent of the catchment comprises wasteland and bare-rock areas associated with quarrying sites. Limestone sediments from these areas can enter the lake system, contributing to sedimentation.
The study also highlights the role of Kondabal, an area historically known for kilns, quarries and mines. Quarrying activity has been associated with increased calcium entering the lake, which researchers said can contribute to sedimentation and nutrient accumulation.
Tourism is another source of pressure on the lake. The researchers noted that motorboat activity and oil spills can contribute to pollution, while increasing human activity around the lake has compounded waste-management problems.
Manasbal is also known for its aquatic biodiversity, including fish and birds, as well as extensive growth of lotus (Nelumbo nucifera) during July and August.
The review described the lake as an important habitat for aquatic birds and noted that it has been recognised as one of Kashmir’s major bird-watching sites. Its fisheries and other resources also support local economic activity.
The researchers warned that eutrophication, driven by excess nutrients, can promote algal growth and lead to deterioration of water quality and the wider aquatic ecosystem.
The study noted that Manasbal has a water residence time of about 1.2 years and a reported sedimentation rate of 0.44 centimetres per year, factors that are important for understanding the movement and accumulation of pollutants and sediments within the lake.
The review also highlighted changes in land use around the lake, including the expansion of agricultural, plantation and built-up areas. It recommended reducing erosion and sediment inflow through measures including reforestation of degraded areas with native species.
The researchers called for tighter regulation of human activities around the lake, improved waste and sewage management, control of pollution sources and restoration of degraded areas.
They said protecting Manasbal was important not only for its biodiversity but also for fisheries, tourism, local livelihoods and the cultural value associated with the lake. (KNO)
