Failure of authorities to undertake sustained deweeding of Dal lake is taking a heavy toll on fragile eco-system of the water body.
Lakes and Waterways Development Authority (LAWDA) entrusted with Dal conservation has failed to undertake sustained deweeding operations since July 9. In absence of deweeding, weeds and Red Algal bloom have engulfed the lake stretch from Hazratbal to Boulevard.
Thick mats of red bloom and weeds give ugly look to the lake besides affecting its flora and fauna. "Thick weeds hamper movement of shikaras," said Ghulam Rasool, a shikara owner pointing towards green cover on lake surface at Nishat.
"It is ironical that authorities are sitting over deweeding of the lake. This has affected aesthetic beauty of the lake," said a group of pedestrians near SKICC.
Sources said the scientific wing of LAWDA had earlier this year advised the Mechanical Wing not to remove weeds in some parts of the lake including Hazratbal basin to prevent sprouting of Algal blooms. However, the wing went ahead with deweeding in problematic spots triggering growth of Algal blooms across the lake.
Pertinently, Dal receives waters into its Hazratbal basin from Marsar, a glacial oligotrophic alpine lake through two main sub-watersheds namely Dhara Danihama and Dachigam. Before reaching the lake, the waters pass through denuded mountains carrying tons of silt and nutrients with it— propelling growth of weeds. Annually, over one lakh cubic meters of weeds are removed from the lake. LAWDA undertakes de-weeding by four harvesters and two truxors.
Environmentalist Dr MRD Kundangar said Red Euglenoid bloom has probably reappeared in the lake after 16 years.
"Euglena causing organism was first noticed by me in August 1990 in the lake. The causal organism responsible from the same was identified as Euglena Sanguine, a unicellular protozoan which is treated both as plant n animal). This very organism turns into bloom due to excess of Ammonical -Nitrogen and Nitrate-Nitrogen and carbon dioxide as studied by my scientific team while at Hydrobiology Laboratory at SP College Srinagar," Dr Kundangar said.
He said after detailed studies about the organism, its life cycle and mode of reproduction, it was decided that aeration of the infected areas is the immediate solution to check growth of this very Red Euglenoid Bloom.
"Japanese type of floating aerators were installed in a similar way that of Bhopal lake which too was infected with Cynobacterial bloom ( Microcystis erignousa ). Based on Canadian technology, a permanent aeration system was also installed in the Lam area which was the epicentre of the Euglenoid bloom," he said.
"The reappearance of the Red Euglenoid Bloom in my opinion is due to excessive and untimely deweeding resulting in release of nutrients from the enriched lake bed, besides stagnation of waters and removal of aerators. The bloom at present looks uncontrolled because of the gross mismanagement and deployment of motorboats in the infected area which has further aggravated the issue," he said.
However, Dr Kundangar maintained that the bloom will stay till the temperature is not lowered. "But the bloom is not hazardous to humans though it can have Fish kill."
Ajaz Rasool, a hydraulic engineer recommended scientific measures to control the prolific weed growth.
He said in due to excess of fertilizing nutrients available in Dal and Nigeen lake there is a prolific spread of mats of green algae. "As temperature start rising, even the emergent weeds start showing their growth. The entire water expanse shows large patches of these prolific floating and emergent weeds which spoils the aesthetics of water surface," he said.
Elaborating he said to maintain a clean lake from aesthetic considerations and nutrient expose mechanism, there is urgent need to resort to de-weeding and skimming operations.
"These operations are normally done simultaneously by mechanical or manual means much before the floating mats of same settle down to the bottom. There is need to have under vegetal cover of lake to be optimum and conducive. This will help in affording Dissolved Oxygen to the shallow lake waters through photosynthesis rather than allowing the weed mats to cut off penetrative of sunlight," he added.
A senior officer of LAWDA wishing not to be named said the delay in deweeding was caused due to prevailing law and order problem in Kashmir.
"Among other factors, dry spell has propelled growth of weeds. The problem has been compounded by restrictions and shutdown as the staffers entrusted with deweeding operations could not attend their duties. However, we have resumed the deweeding operations. We will conduct manual and mechanical deweeding in double shifts. The bloom will naturally disappear with decrease in temperature," he said.