Cultural eutrophication, tourism and societal disconnect- Potential factors harming the wellness of high altitude Kashmir Himalayan lake- The Dal

Abstract

Intensive farming practiced in the surrounding area of Dal Lake and its floating gardens leads to an enhanced vulnerability of crops to pests and indiscriminate use of pesticides. Possible transfer of these hazardous molecules from vegetable fields to the aquatic environment of the lake, poses a potential threat to the aquatic species and human health as well. The myriad ways in which people use the lake along with the numerous pollutant-generating activities have stressed the lake ecosystem in diverse ways. In the present investigation conducted from 2009 to 2012, 135 samples of fish including 81 samples of Schizothorax niger, Schizothorax esocinus ( Ale Gaad / Churuu Gaad) and 54 samples of Cyprinus carpio Spp (var: communis & specularis {Punjab Gaad}) were collected from three basins of Dal . The samples were analyzed for seven commonly used pesticides with GC-MS/MS. It was found that 73 samples (54.07%) out of 135 were contaminated with chlorpyrifos with mean concentration of (0.0009 ± 0.0010ng/kg) with concentration ranging from undetected to 0.003ng/kg. Level of pesticide was higher in pesticide use season than non use season except in 2009 when levels were same. Presence of sub acute exposure of chlorpyrifos in a locally consumed Schizothorax niger, Schizothorax esocinus species and not in Cyprinus carpio spp. The low dose exposure to pesticides through food chain like fish can be a major contributor for presence of pesticide residual levels in human blood. Schizothoracids being more susceptible to the pesticide than carps. Water of the lake is continuously being fed with human excreta through sewage dumping, although some partial treatment of the sewage is done via treatment plants. The lake is thus a contributing vehicle to the presence of various gastrointestinal viruses like roatvirus, which has been detected at various locations of lake. The lake is in a serious state of eutrophication mostly cultural and ways and means for lake restoration have not proved to be fruit full till date. Sewage from the settlements around the lake and the large population (estimated 50,000-70,000) living on hamlets within the lake on floating islands and houseboats enters the lake without treatment. More than 111 tons of Phosphorus and 380 tons of nitrogen are estimated to flow into the lake from point sources and 4.5 tons of P and 18.1 tons of N from non-point sources. The “Dal” is used for major economic activities relating to tourism, site seeing, recreational activities, fisheries, harvesting of food and fodder plants. The floating gardens of the lake that have originated with time have now assumed a status of biggest biggest vegetable producing bowl of Kashmir. The state of disconnect between lake dwellers, catchment population and general public with the lake seems to be a worrying factor.

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