Water bodies in Kashmir have been marred by extensive pollution, siltation and encroachments, greatly affecting the fish that live in them
A sudden appearance of dead trout fish at the surface of a pond in Handwara recently garnered considerable interest and concern in Kashmir. Our first reaction is to suspect poisoning of the water body. However, the occurrence of such events is mostly related to the problem of reduced oxygen in nutrient-rich or eutrophic systems which have a higher tendency of experiencing fish deaths. The water bodies of Kashmir valley are filled with large quantity of organic waste, which ultimately lowers the dissolved oxygen in the water and causes fish to die of asphyxiation. Most species of fish are distressed when the oxygen content falls to 2-4 mg/L, whereas mortality usually occurs at concentrations less than 2mg/L. Besides this, the harmful algal blooms of blue-green algae also known as cyanobacterial blooms can cause fish mortality due to the wide range of toxins produced as part of their metabolic processes.
In October 2017, a typical scenario occurred when fish were observed at the water surface gasping for breath on a 2.5km stretch of Jhelum River from Gow Kadal to Weir Chattabal area of Srinagar city. The fish species caught in distress were the native fish of Kashmir known as Schizothorax or Kasher Gaad, which prefer to live in oxygen-rich waters and are very sensitive to low dissolved oxygen levels. Upon investigation, the fish distress was attributed to the depleting levels of dissolved oxygen due to the release of polluted and stagnant water via two localised source canals, Sonar Kol and Kot Kol, into the Jhelum River. A few years back in 2012, an en-masse death of fish was witnessed in the Nigeen Lake, clear evidence of the aquatic hypoxia triggered by the synergist effect of high temperature, low dissolved oxygen and cyanobacterial bloom. Thousands of fish were reported dead in the lake, mostly Crossocheilus diplochilus, which were seen lying dead on the shore. Other affected fish species included Schizothorax sp., Cyprinuscarpio and Puntiusconchonius.
An analysis conducted by various researchers on fishery resources of the Dal Lake, Wular Lake and the Jhelum River indicates that the fish diversity has declined due to various factors, like destruction of breeding grounds, inflow of silt and sewage from peripheral areas, agricultural runoff, encroachments and over exploitation of fishery resources. The population of Schizothorax is on decline owing to the depletion of dissolved oxygen on account of inflow of raw sewage. Another fish species whose number has considerably reduced is the Botia birdi (Rama gurun).
Grave concern is being voiced by people from different walks of life at the deteriorating condition of the water bodies of Kashmir, including Dal, Wular, Khushalsar, Gilsar and Anchar lakes. These are under tremendous anthropogenic pressure along the catchment areas and as such are not getting sufficient time to restore their natural structure. In order to prevent the decline of aquatic life, we need to quantify and communicate the various ecological, economical and public health benefits from safeguarding the condition of aquatic ecosystems in the valley. Everything has its saturation point, beyond which the capacity of tolerance gives in and there occurs deviation from nature. It is our responsibility to establish a genial relationship with nature and high time for the authorities to orient their efforts towards the restoration of the ecological health of water bodies, so as to ameliorate fish distress.
The writer has a Master’s in Environmental Science from Kashmir University. She teaches at Kashmir Harvard Higher
Secondary Institute, Habak Naseem Bagh Srinagar. [email protected]