Mumbai: Twenty black and white sharks were found dead in 400-year-old Sion pond on Monday, forcing the Brihanamumbai Municipal Corporation (BMC) to order a probe.
Locals and a Sena corporator blamed the excessive use of chemicals in making Ganesh and Durga idols, which are immersed here, dumping of flowers, plastic waste, and increasing biochemical oxygen demand (BOD).
Residents also said that though the lake receives funds from the BMC for upkeep, about 400 fishes die around Holi and Diwali every year.
“After being maintained by a trust for several years, the lake was taken over by the BMC around three years ago,” Mangesh Satamkar, Sena corporator from Sion, said.
Keshav Ubale, assistant commissioner, F-north, who visited the pond, said the deaths will be investigated. “There is definitely something fishy because there are no sewer lines anywhere near the pond. Our team of engineers have taken water samples for analysis.”
To keep the water clean and aerated, the BMC annually dissolves 300 kg aluminium potassium sulphate into the pond. Vijay Kumar, a social worker, said the presence of aquatic animals ensures that the water is potable. Mr. Satamkar said creation of a fountain will ensure the movement of water layers, and solubility of oxygen increases, which leads to decreasing the BOD. “The BMC each year spends unnecessarily on painting walls and building stages around it, but no significant amount is spent on cleaning the pond.”
After seeking help from the BMC for years, Dr. Praveen Bhatt, a local resident, has started building a fountain. “I am spending ₹40,000 for the fountain.”
Mr. Ubale denied having knowledge of a resident preparing to install a fountain on his own. “We have not been approached by anyone. I will inquire into this.”
Rajshree Shirwadkar, a BJP Corporator, said that the BMC is working towards closing a deal with Probac Biologicals, an Australian company. The company, according to Ms. Shirwadkar, has a solution for treatment of water, which has a composition of algae, seaweed, and water. “It reduces the BOD and the chemical oxygen demand drastically in 24 hours, and it is also harmless to the human body.” “We are negotiating on terms and conditions because of pricing, although we are hopeful to start treating water bodies in Mumbai shortly,” Vyomesh Panchmatia, director of Probac Biologicals, said.