Jayanti Sarovar is a fountain of fresh life on Thursday after Jusco’s clean-up mission. Picture by Bhola Prasad

From fish funeral to fish fairytale, Jamshedpur’s Jayanti Sarovar has started an arduous and appreciable journey with civic guardian Jusco cleaning the landmark lake before monsoon and planning another slew of measures to protect it all the year round.

The 20-acre Sarovar inside Jubilee Park had become an eyesore and watery graveyard as algae, hyacinth and other aquatic species blanketed 40 per cent of its surface, thereby cutting off oxygen supply and killing more than 200 fish on May 5.

Jharkhand High Court, hearing a PIL three days later, had sought a report from the East Singhbhum district administration and Jusco by May 15. Court interest got Tata Steel subsidiary Jusco cracking and the lake was restored to its former glory on Wednesday.

“We formed a 40-strong dedicated workforce to clean the lake. Work began in the last week of May and we managed to achieve our goal yesterday,” said a senior official of Jusco’s horticultural department.

Algae and weeds block sunlight, squeezing oxygen supply to a lake. Also, they have a short lifespan. So, when they die, bacteria decompose them and consume oxygen in the water, resulting in hypoxia (deficit of oxygen). Fish die if the concentration of oxygen is less than 4ppm (parts per million), precisely the reason why dozens of Indian carp (mrigal), katla, rohu and tilapia died.

To avoid the unfortunate rerun, Jusco has started operating four fountains at the lake for better aeration (increasing saturation of oxygen in water). Two more fountains will be launched within 10 days. “Aeration can be achieved by infusing air at the bottom of the lake through surface agitation. Fountains help mix water and air, and thereby transfers oxygen,” a Jusco official explained.

The civic utilities firm has also completed desilting and dredging work near the two inlet points at Old Court and Tata zoo ends through which toxic waste from the city was believed to have entered the lake on May 4 night, killing fish in such large numbers. “Desilting pits will be set up near inlet points by August to prevent toxic water from entering the lake,” the official added.

Jusco has also planned lime and potassium permanganate treatment for the lake during monsoon.

Liming is known to benefit aquatic species by offering calcium for shell growth in molluscs, exoskeleton hardening in insects and scale production in fish. The treatment also offers carbon dioxide for photosynthesis. Carbonates formed are stored at the bottom of the lake and released into the water column to act as a buffer and prevent wide swings in pH levels.

Jusco spokesperson Rajesh Rajan said the exercise would be completed within a month.