Coral Reefs in India: All Four Regions and Their Condition

Coral Reefs in India: Where They Are and What Condition They Are In

Published: 5 September 2026

Map of coral reefs in India showing reef areas in Lakshadweep, Gulf of Kutch, Gulf of Mannar, and Andaman and Nicobar

Coral reefs in India are concentrated in four regions: the Gulf of Kachchh in Gujarat, the Gulf of Mannar and Palk Bay off Tamil Nadu, the Lakshadweep Islands in the Arabian Sea, and the Andaman and Nicobar Islands in the Bay of Bengal. That is the list most readers come looking for, and the four-region core is consistent across government, academic and journalistic sources.

The more useful thing to know is that those four regions are not four versions of the same place. They differ in reef type, in water conditions, in how much is protected, and in how much anyone actually knows about their current state. This guide takes them one at a time.

The four regions, and why they are not four versions of the same thing

Reef scientists separate reefs by shape and by their relationship to land, and India has three of the main forms across its four regions.

A fringing reef grows directly against the shore or a short way off it, with little or no lagoon in between. It is the most common form in Indian waters. A barrier reef sits further out, separated from the coast by a lagoon or a channel of open water. An atoll is a ring of reef enclosing a lagoon, formed where reef growth has kept pace as the land beneath it subsided. If you want the mechanism behind those shapes, our companion guide, Coral Reef Formation: How Reefs Are Built and What Takes Them Apart, covers it in detail.

Sort India’s regions by that scheme and the differences appear immediately. Lakshadweep is atolls. The Andamans carry fringing reefs on one coast and the only barrier reef reported anywhere in India on the other. Reefs in the Gulf of Mannar are fringing, wrapped around a chain of islands. Gujarat’s Gulf of Kachchh holds reef growing in some of the harshest water any coral in India has to tolerate, and the sources cannot agree on what to call it.

Coral reefs in India compared across Gulf of Kachchh, Gulf of Mannar, Lakshadweep and Andaman and Nicobar Islands

Lakshadweep: India’s only coral atolls

Lakshadweep is the one place in India where coral atolls are found. Every other Indian reef region is described as fringing, platform or patch reef. This is a matter of geology rather than reporting, so it is stable in a way that condition data is not.

It is also the region with the strongest evidence about what is happening to the coral, because it has the longest continuous monitoring series. A study published in Diversity and Distributions in July 2025, reported by Down To Earth, found live coral cover at survey sites in three atolls, Agatti, Kadmat and Kavaratti, falling from 37.24 per cent in 1998 to 19.06 per cent in 2022. That is a loss of about half the coral present.

Two qualifications matter before you carry that number anywhere. It describes survey sites in three atolls out of twelve, not the archipelago as a whole. And 19.06 per cent is the 2022 endpoint of a long series, not a current reading. Marine heatwave conditions in the Lakshadweep Sea have continued since October 2023, with ICAR-CMFRI documenting severe bleaching driven by that prolonged heat. Whatever those events did to the reefs sits outside the 2022 figures.

The same study points to why the trend runs downward rather than sideways. Coral can rebuild after a bleaching event, but recovery accelerates only when there is a gap of about six years between events. The study period contained three heatwave-linked bleaching events, in 1998, 2010 and 2016. The gaps are closing, and that is the part of the Lakshadweep story worth holding on to.

Coral reefs in India showing declining live coral cover across three Lakshadweep atolls from 1998 to 2022

The Andaman and Nicobar Islands: fringing reefs and India’s only barrier reef

The Andaman and Nicobar group is the largest and most varied of India’s reef regions. Its east coast carries fringing reefs. Along the west coast, reviews report a barrier reef running roughly 320 kilometres, which is the only barrier reef reported anywhere in Indian waters.

Treat that as a long-standing report rather than a current survey result. Both Food and Agriculture Organization review chapters that describe the feature trace the original observation back to Sewell in 1935, and they sit in the same 1990s volume. The archipelago has also experienced documented vertical land movement since, following the 2004 Indian Ocean earthquake. The barrier reef is well attested in the literature. Its present extent and geometry are not something this evidence can settle.

The Gulf of Mannar: 21 islands and the country’s longest restoration effort

Reefs in the Gulf of Mannar are fringing reefs distributed around a chain of 21 islands off the Tamil Nadu coast, between Rameswaram and Tuticorin. The island count is the firmest fact in this region’s record, appearing consistently from the 1990s reviews through to the current Tamil Nadu State Wetland Authority listing.

The islands and their surrounding waters sit inside a designated marine national park, and the wider biosphere reserve around it is recognised internationally as a Ramsar wetland.

This is also where India’s longest-running and largest reef restoration programme operates. The International Coral Reef Initiative reports that between 2002 and 2024 the Suganthi Devadason Marine Research Institute transplanted over 51,000 coral fragments of 20 native species, with survival ranging from 55.6 to 79.5 per cent depending on location and species. Mongabay India reports the restored area at roughly 40,000 square metres.

Forty thousand square metres is four hectares. Set against a reef region measured in tens of square kilometres, that is a small fraction, and the honest reading is that the programme demonstrates transplanted coral can survive at scale over two decades. Survival is not the same as recovery, and four hectares is not a rebuilt gulf.

The Gulf of Kachchh: reefs in the hardest water in India

Coral in the Gulf of Kachchh grows on and around islands on India’s north-west coast, in water with high turbidity and an extreme tidal range. Reefs elsewhere in India need clear, sunlit water. These ones tolerate conditions that would kill most reef-building coral outright.

The sources split on what to call them. Some technical reviews class them as platform reefs, others as fringing. Both labels are in current use and this guide picks neither, because the evidence does not settle it.

Formal protection came in two steps. A marine sanctuary of 270 square kilometres was declared in 1980, and a marine national park core of 110 square kilometres followed in 1982, covering 42 islands inside the park boundary on the Jamnagar coast. Those are protected-area figures. They describe administrative boundaries, not how much reef sits inside them, and the two should never be read as the same measurement.

Coral outside the four regions

Coral in India is not confined to the four regions. Scattered patch reefs, small isolated outcrops rather than continuous reef structure, occur along parts of the west coast, including the Malvan area of Maharashtra. The Indian National Centre for Ocean Information Services lists Malvan alongside the four main regions in its own coral reef service description.

Here is why source lists disagree on how many reef regions India has. Some count four, some five, some separate Palk Bay from the Gulf of Mannar and reach six. They are counting different things: major reef formations in one case, all areas where coral grows in another. The four-region core holds across all of them.

How much reef does India actually have?

You will see one number everywhere: 2,375 square kilometres. It appears in government material, in review articles, in journalism published as recently as May 2026, and it is almost never dated.

It comes from a 1997 mapping exercise. The Agriallis technical review states the source directly and lists it in full: Coral Reef Maps of India, produced by the Department of Ocean Development with the Space Applications Centre, Ahmedabad, in 1997.

So the figure has a provenance, and it is nearly three decades old. No newer national survey figure has replaced it in general use. That does not mean India’s reef area is now smaller, or larger, or unchanged. It means the confident number in circulation rests on a survey conducted before most of the bleaching events that shaped the last quarter century. When you next meet 2,375 square kilometres in a headline, that is what you are reading.

What protects these reefs

Reef-building corals in India carry the highest level of protection the law offers. A Ministry of Environment and Forest notification dated 11 July 2001 brought hard corals into Schedule I of the Wild Life (Protection) Act, 1972, which is the schedule reserved for species given total protection with the strictest penalties for trade. The National Maritime Foundation and Project Seahorse both record the listing.

Listing is not the same as enforcement. The Agriallis review notes that monitoring of Gulf of Kachchh park reefs has been restricted to irregular environmental impact assessments. A reef can sit inside a national park, inside a biosphere reserve, and at the top of the country’s protected species list, and still have no one measuring what is happening to it year on year.

Conclusion

India’s reefs are four different places with four different stories, and the quality of what is known about them varies just as widely. Lakshadweep has a 24-year monitoring series and a clear downward trend. The Gulf of Mannar has two decades of restoration data. The Andamans rest on reviews from the 1990s citing observations from 1935. And the national area figure that ties them all together in every summary you will read comes from a survey conducted in 1997.

That gap between the confidence of the numbers and the age of the evidence behind them is the real finding here. If a reef region’s condition cannot be described without reaching back three decades, what would it take for India to know what its reefs look like now?