Researchers in India say they have documented a giant coral colony near Kadmat Island in Lakshadweep, spread across an estimated 4,250 sq m.
The Pavona clavus formation, known locally as the “Potato Patch”, could be among the largest known living coral colonies recorded anywhere in the world.
Preliminary growth-rate estimates suggest the colony may be 700 to 1,800 years old, though researchers say this needs scientific dating.
The survey found that 58.47% of the coral tissue was alive, indicating a relatively healthy state despite repeated marine heatwaves, bleaching events and cyclones.
Scientists say the finding could help advance research on coral longevity, reef resilience, climate adaptation and conservation in the Indian Ocean.
Researchers in India say they have documented what could be the largest known living coral colony in the world near Kadmat Island in the Lakshadweep archipelago. The size is equivalent to about 1.05 acres, or 0.43 hectares — roughly half the size of an international football pitch.
The coral colony, known locally as the “Potato Patch”, covers an estimated 4,250 square metres and belongs to the species Pavona clavus, according to researchers involved in the survey. The colony may also represent a long-lived coral structure around 700 to 1,800 years old, based on preliminary estimates of its growth rate and is possibly among the oldest living coral structures in the region, researchers said.
But they added that the age estimate would need to be confirmed through techniques such as sclerochronology or radiometric dating. The discovery was made during a marine biodiversity survey at Kadmat Island, said Idrees Babu, a scientist with the Department of Science and Technology, Government of India.
Researchers from international marine conservation organisation Research and Environmental Education Foundation, or REEF, worked with wildlife conservation organisation The Habitat Trust to measure and quantify the coral colony at the popular diving site, Babu said.
Recent reports have documented exceptionally large coral colonies elsewhere, including a colony of about 3,973 sq m on the Great Barrier Reef in Australia, extensive formations in the Red Sea and a colony covering nearly 1,000 sq m in the Solomon Islands.
Babu said the Lakshadweep colony appeared to exceed those records in size. “The discovery of the ‘Potato Patch Coral’ (Pavona clavus) at Kadmat Island, Lakshadweep, covering an estimated area of approximately 4,250 square metres, represents an extraordinary scientific finding,” he said.“Based on currently available records, this colony appears to be the largest known living colony of Pavona clavus documented anywhere in the world.”
The continuous, meadow-like coral formation lies in the south-eastern waters of Kadmat Island, beginning on the reef flat at a depth of 5.2 metres and descending along a steep slope to about 20 metres, according to the researchers. The patch extends up to 85 metres in length, 50 metres in width and 2.8 metres in height, covering an estimated area of 4,250 square metres.
Babu said the formation was so large that it took more than an hour and a half to traverse fully. The lack of regional baseline data on rare coral colonies of this size prompted researchers to measure its full extent, he said.
The scientific exploration was led by Habeebu Rahman, research fellow at REEF, along with Abishek Jamalabad, marine programme lead at The Habitat Trust; Mohammed Sijahudheen, research fellow at REEF; Mohammed Nisham, diving instructor; Ilthuthmish Nasarulla, dive master; and field assistants Ajmeer Khan and Mukhbil, Babu said. The survey found that 58.47 per cent of the coral tissue was alive, reflecting what researchers described as a relatively healthy state.
The habitat continues to support diverse fish assemblages, underscoring its ecological importance within the Lakshadweep reef system, the researchers said. “It is an extraordinary coral formation hidden within the depths of the Indian Ocean, shedding new light on the complexity and resilience of these marine ecosystems,” Babu said.
Researchers said the record highlights the ecological value of Lakshadweep’s reefs and the importance of the archipelago as a possible refuge for long-lived and structurally dominant coral colonies. The Lakshadweep archipelago, India’s only atoll island chain, supports marine biodiversity, food security through fisheries, coastal protection from erosion, tourism and carbon sequestration, researchers said. The finding could help advance research on coral longevity, reef resilience, climate adaptation and conservation of large coral colonies in the Indian Ocean.
The coral has long been known to local divers, according to Shamsudheen S, an open-water diving instructor from Kadmat Island who initially guided the research teams. Shamsudheen said the site had been known as a diving location since 1995.
“We have also observed the presence of two other smaller P. clavus patches on the island,” he said. He said the “Giant Potato Patch” had withstood multiple adverse environmental events over the past three decades. “In this context, it functions as a natural time capsule, offering valuable insights into past oceanographic changes across the atoll system and serving as a reference point for modelling future environmental responses,” he said.
Researchers said understanding the colony’s long-term survival was important for conserving other reefs across the archipelago. Previous studies in the journal Coral Reefs have documented the impacts of repeated tropical cyclones and major El Niño-Southern Oscillation events in 1998, 2010 and 2016, which caused sharp increases in coral mortality and significant declines in live coral cover, the researchers said.
Recovery after the 2010 El Niño event was reported to be about four times slower than recovery after the 1998 event, they added.
The resilience of coral reefs is increasingly being tested by prolonged bleaching events and marine heatwaves, which have caused extensive coral mortality and biodiversity loss worldwide, researchers said. REEF said it would continue monitoring the giant patch and expand research on other large coral colonies across Lakshadweep, particularly in anticipation of a possible El Niño event this year.
Babu said the finding added a new dimension to reef studies in the region and offered renewed hope for the long-term persistence of coral ecosystems in Lakshadweep waters.
“Such extensive, long-lived corals are of particular scientific importance, as they preserve unique biological, genetic and paleoclimatic information, having withstood multiple environmental stressors over time,” he said.