NEW DELHI: The 4,000-year-old Chilika Lake in Odisha is a major source of livelihood for thousands of local fishermen. The lake’s fish population, including some endangered species like Irrawaddy dolphin, had started to deplete due to ecological changes in the water body.
A team from IIT Madras, led by Prof R. Sundaravadivelu, found the lake’s mouth shifting towards the northeast region reducing the flow of seawater into the lake. This had affected the biodiversity, ecology and economy of the area.
The researchers used satellite imagery and hydraulics modelling to identify the problem and then came up with an eco-friendly dredging methodology to remove sedimentation and widen the mouth of the lake.
Their intervention has benefited 200,000 fishermen living in 132 villages around the lake spread over Puri, Khurda and Ganjam districts. Their fish catch from the lake has grown seven-fold and the population of highly threatened Irrawaddy dolphin has increased by three times since 2000, when the project was started.
It has also reduced risks of flood and controlled growth of harmful freshwater weeds. The restoration of the lake’s ecosystem has also boosted ecotourism.
After the restoration, the lake has been removed from the number one spot in Asia’s most threatened wetland sites on Montreux record. Chilika Development Authority has also received several awards for their efforts including the Ramsar Wetland Conservation Award and Evian Special Prize.
“The Chilika Lake was restored with a cost of Rupees 10 crores by opening the mouth and other related works in six months’ time which has resulted in fish catch worth Rs.100 crore and revenue of Rs. 35 crore due to tourism every year," R. Sundaravadivelu, Institute Chair Professor, Department of Ocean Engineering, IIT Madras said in a statement.
It was found that the tide levels at Satapada before the opening of the mouth was 10 cm. After opening it had improved to 60 cm, indicating more tidal inflow and stabilization of the salty water nature of the Chilika lake.