The Chilika lagoon in Odisha is over 4,000 years old. (File)
New Delhi:
A research project by the Indian Institute of Technology (IIT) in Madras has helped Lake Chilika in Odisha, Asia’s largest body of brackish water, to triple the population of Irrawaddy’s dolphins.
The researchers conducted geotechnical, hydraulic and satellite imagery studies and developed a dredging methodology with minimal impact on the ecosystem of the lake.
The dredging process includes excavating (loosening or dislodging) bottom material, removing loose material to the dredging vessel, and ultimately transporting the material to the placement area.
The intervention of the first institute also benefited the more than 200,000 fishermen living in 132 villages, because it led to a sevenfold increase in catches of fish and tourists to coexist with the ecosystem of the lake with minimal disturbance of the environment says the team.
“The Chilika lagoon is over 4,000 years old and spans the Puri, Khurda and Ganjam districts of Odisha. The highly productive ecosystem of the lake supports the livelihoods of fishermen and also serves as drainage for the basin of the Mahanadi River, “R Sundaravadivelu, professor in the department of Ocean Engineering, said IIT Madras.
“The lake was in a degraded state and included on the list of threats by the Ramsar Convention in 1993. This justified urgent action for the restoration of the lake,” he added.
“Geotechnical, hydraulic and satellite imagery studies have shown that the Chilika spindle is constantly evolving. The sandbank has widened and the position of the mouth has constantly shifted, generally moving north The mouth was described as having a width of approximately 1.5 km in 1780 and had decreased by half in forty years in 1820. “
“It also showed that the mouth of Lake Chilika originally located near Sipakuda in 1800 has gradually moved over the past 200 years to the north side towards Arkhakuda,” he said.
The IIT Madras team has developed the dredging methodology identifying the location of dredging as well as the disposal and selection of appropriate dredges with minimum impact on the ecosystem.
“Based on the results of this successful hydrological intervention, flooding and freshwater weeds are reduced. The hydrological intervention restored the lake ecosystem and improved biodiversity. Fish production has increased 7-fold and the highly threatened Irrawaddy dolphin population has increased. ” Says Sundaravadivelu.
“The improvement of fishery resources and the increase in the dolphin population of Irrawaddy have favored ecotourism which has immensely benefited local fishermen,” he added.
Restored at the price of Rs 10 crore by opening the mouth and other related works in six months ”, the lake is now off the list of threatened (Montreux record).
The Chilika Lake Authority has developed an ecosystem health report card and periodic monitoring of salinity, fish and dolphins, freshwater weeds, birds and other biological parameters is underway .
