Chilika Lagoon's Shrinking Power: A Battle Against Silt and Tourism
Chilika Lagoon once spread across a vast 1,165 square kilometers during monsoon seasons. Its waters swelled with river inflows and powerful tidal pulls. The lagoon's impressive depth and width created a strong tidal prism. This large volume of water flowing in and out during each tidal cycle enabled vigorous exchanges with the sea. It allowed Chilika to flush out most of the silt that rivers brought in annually.
The Critical Changes Beneath the Surface
Today, Chilika's effective water spread fluctuates between 930 and 980 square kilometers. The more alarming transformation, however, lies beneath the water's surface. Flushing capacity depends not only on area but on volume as well. Multiple studies conducted over recent decades reveal a troubling trend. Chilika's tidal prism has diminished by approximately 30% to 40% compared to its pre-1990s condition.
By the late 1990s, Chilika crossed a critical geomorphic tipping point. Its natural flushing capability could no longer maintain proper salinity levels or support healthy fisheries. In 2000, an intervention by IIT Madras provided temporary revival. This assistance, however, did not represent true recovery. The lagoon's inherent ability to cleanse itself has fundamentally weakened.
Tourism's Double-Edged Sword
Tourism has emerged as Chilika's second economic pillar after fisheries. This industry reshapes livelihoods, landscapes, and expectations around the lagoon. A recent study documented dramatic growth in visitor numbers. Annual tourists visiting Chilika rose from 1.2 lakh in 2005–06 to 7.5 lakh in 2019-20.
At Satapada, multiple fast propeller-driven boats often crowd around Irrawaddy dolphin pods. This creates an ecologically fragile situation. Tourism in the lagoon demands strong ecological discipline. The northern edge of Chilika at Mangalajodi demonstrates this principle effectively. Once notorious for bird poaching, this village transformed itself through community-led ecotourism centered on migratory birds. Mangalajodi now stands as a widely cited model of successful and sustainable tourism.
The Coastal Dynamics and Future Solutions
Along the Odisha coast, powerful longshore currents relentlessly push sand northward. Historically, the lagoon's depth and tidal force countered this movement. Hydraulic strength alone kept the mouth open. The future of Chilika therefore depends on actions far beyond its immediate mouth.
Several essential measures must be implemented. Sediment in the lake must be reduced upstream. Depth needs restoration in areas where water flow matters most. Circulation must be freed inside the lagoon itself. These actions include soil conservation and reforestation in river catchments. They involve targeted desiltation of key channels. They require removal of internal barriers like harmful pen culture. Maintenance of a single strong sea connection remains crucial. These steps are not optional—they are absolutely essential for Chilika's survival.
