Size
About 1,100 sq km in the monsoon, shrinking to 900 sq km in the dry months.
Its birds
Over 1.1 million birds counted in its 2026 winter census.
Its dolphins
India’s only home for the Irrawaddy dolphin.
Its rank
Asia’s largest, and the world’s second-largest, lake of its kind.
- Asia’s Largest Brackish Lagoon
- A Winter Home for a Million Birds
- A Lake That Nearly Choked to Death
- Second in the World, Not First
- Cutting a New Mouth to the Sea
- The World’s Southernmost Irrawaddy Dolphins
- Poachers Who Became Protectors
- The Real Exam Trap on This Topic
- A Record Count, With a New Visitor (2026)
The Basics
Asia’s Largest Brackish Lagoon
- What it is: Asia’s largest brackish-water lagoon, spread across Odisha‘s Puri, Khordha, and Ganjam districts.
- Where it meets the sea: it opens into the Bay of Bengal near Satapada, cut off from the sea by a long sand strip.
- The seasonal swing: the lake covers about 1,100 square kilometres in the monsoon. It shrinks to roughly 900 square kilometres in the dry season.
- A real first: in 1981, Chilika became one of India’s first wetlands named a Ramsar Site of world importance.
Worked example: picture pouring a jug of seawater and a jug of river water into the same tub. That mix — part salty, part fresh — is what fills Chilika. It’s why the lake supports both sea fish and river fish at once.
True or False: Chilika Lake is Asia’s largest brackish-water lagoon.
Its Birds
A Winter Home for a Million Birds
- Nalabana: a 15-square-kilometre mudflat at the lake’s heart. It’s a bird sanctuary that hosts hundreds of thousands of migrating birds every winter.
- Changing salt levels: how salty the water is changes across the lake. It depends on how close each part sits to the sea mouth, and to fresh river water.
- River inflows: fresh water arrives mainly through the Daya, Bhargavi, and Nuna rivers — branches of the Mahanadi — feeding the lake’s northern end.
Its Near-Collapse
A Lake That Nearly Choked to Death
- The problem: by the early 1990s, heavy silt had blocked the lake’s mouth. Its water surface shrank, and weeds that don’t belong in salt water began to spread.
- The consequence: this decline got Chilika placed on the Montreux Record in 1993 — a world list of wetlands in real trouble.
Think it through. Why would blocking the lake’s mouth to the sea cause freshwater weeds to take over?
Show the explanation
Chilika stays healthy because seawater keeps flowing in and out through its mouth. Block that mouth, and less salty water gets in. The lake slowly turns more fresh than salty. Plants that can’t survive in salt water suddenly can grow — and with nothing to stop them, they spread fast.
Its World Rank and Islands
Second in the World, Not First
- World ranking: Chilika is Asia’s largest brackish lagoon. Worldwide, it ranks second, behind New Caledonia’s lagoon system in the South Pacific.
- Islands within: small islands dot the lake, including Kalijai Island, home to a temple from 1717, and the fittingly named Honeymoon Island.
- A winter fair: every January, the Kalijai temple draws big crowds for a Makar Sankranti fair, with boats carrying visitors across open water to reach it.
The Real Exam Trap on This Topic
- The trap: exams test whether you actually know why a lake formed the way it did, not just its name.
- The real test: Chilika is a lagoon, cut off from the sea by a sandbar. That’s a different origin from lakes formed by tectonic movement, like Bhimtal, landslides, like Gohna, or a meteor strike, like Lonar.
- How to prepare: pin each lake type to one real example — “lagoon” to Chilika — and matching questions stop being a guessing game.
- CDS-II 2017 Asked students to match four Indian lakes — Bhimtal, Ashtamudi, Gohna, and Lonar — with their correct formation type. Answer: Bhimtal is tectonic, Ashtamudi is a lagoon, Gohna formed from an 1893 landslide, and Lonar is a meteor-impact crater lake. View CDS-II 2017 GK Paper, Q99 →
Its Recovery
Cutting a New Mouth to the Sea
- The fix: in September 2000, engineers opened a new sea mouth. They based it on models built by CWPRS Pune. It brought back the lake’s tidal flow and salt balance.
- It worked: Chilika came off the Montreux Record in 2002 — the first Ramsar site in Asia ever removed from it.
- The payoff: fish catches rose roughly sevenfold after the fix, helping more than 200,000 fishing families who depend on the lake. The Chilika Development Authority won the Ramsar Wetland Conservation Award that same year.
Worked example: picture a clogged drain finally cleared out. Water that had been stuck starts flowing freely again. That’s exactly what the new sea mouth did for Chilika — one cut, and the whole lake’s chemistry reset.
True or False: Chilika Lake was removed from the Montreux Record of troubled wetlands after its sea mouth was restored.
Its Dolphins
The World’s Southernmost Irrawaddy Dolphins
- A real rarity: Chilika holds India’s only known group of Irrawaddy dolphins. It’s the single largest home for this species anywhere in the world.
- A real recovery: numbers have grown from around 150 in 2003 to roughly 158 at the most recent full count. Years of local conservation work made the difference.
Mangalajodi’s Turnaround
Poachers Who Became Protectors
- Mangalajodi: a wetland village on Chilika’s edge. It was once known for poisoning birds with the pesticide furadan, to sell as meat.
- The turnaround: since 1998, with help from the NGO Wild Orissa, former hunters retrained as guides and patrollers. The poaching stopped within two decades.
- The result: Mangalajodi now draws over 300,000 wetland birds, and supports around 85 local families through bird-watching tourism instead.
Think it through. Why would paying poachers to become bird guides actually work better than just policing them?
Show the explanation
A ban with no other income just pushes hunting underground — people who need the money keep doing it, only more carefully. Turning former hunters into paid guides gives them a real reason to want the birds alive: more birds mean more tourists, and more tourists mean more income. Their own skill at finding and tracking birds, once used to hunt them, became the same skill that now protects them.
A Record Count, With a New Visitor (2026)
A Record Count, With a New Visitor (2026)
- The census: Chilika’s January 2026 annual bird count found 1,132,200 birds from 196 species. That’s up from 1,127,228 the year before. (Source: Pragativadi)
- A new face: among the birds spotted was a Mongolian gull, a rare sighting for the lake. (Source: Pragativadi)
- Why it matters here: the count covered all five of the lake’s wildlife zones in a single day. It’s a direct payoff of the same 2000 sea-mouth fix described earlier in this article.
Quick Q&A
Q: What kind of lake is Chilika, and what’s a simple way to remember it?
A: A lagoon — cut off from the sea by a sandbar, but still linked to it. Pair “lagoon” with Chilika to avoid mixing it up with other lake types.
Q: What made Chilika a global conservation success story?
A: Cutting a new sea mouth in 2000 restored its salt balance, getting it removed from the Montreux Record of troubled wetlands in 2002.
Q: Why is Chilika important for the Irrawaddy dolphin?
A: It holds India’s only known population, and is the species’ single largest home anywhere in the world.
Q: How did Mangalajodi village change its relationship with Chilika’s birds?
A: Former bird poachers retrained as guides and patrollers from 1998, ending the poaching and building a bird-tourism economy instead.
✅ Test Yourself
Question 1 of 1
Parent guide: India’s River Biodiversity: Fish, Dolphins, Gharials and Freshwater Conservation
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