Coral colony discovered by mother and daughter citizen scientists could be world largest

abc.net.au · Feb 26, 2026 · Collected from GDELT

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Scientists have welcomed the "impressive" discovery of what is thought to be the largest coral colony on the Great Barrier Reef and possibly in the world.Sophie Kalkowski-Pope and her mum, Jan Pope, discovered the 111-metre-long Pavona clavus colony offshore from Cairns in Far North Queensland.The mother and daughter knew they had found something special on the first dive. (Supplied: Jan Pope)They were diving for Citizens of the Reef's Great Reef Census when they realised they had found something special."It's just these meadows of rippling coral as far as the eye can see," Ms Kalkowski-Pope said."It's just an absolutely stunning ecosystem and this hotspot of life."Jan Pope and Sophie Kalkowski-Pope were recreational diving when they made the discovery. (Supplied: Citizens of the Reef)After the pair made the discovery late last year, Ms Kalkowski-Pope returned with the charity in January to map and measure the structure with drones and measuring tapes, and created a 3D model.Their preliminary measurements had an estimated footprint of 3,971 square metres.Ms Kalkowski-Pope, a marine operations coordinator at the charity, said it could be "the largest documented and mapped coral colony in the world"."We know for a fact that definitely here on the Great Barrier Reef, nothing has been discovered to this scale before," she said."Even globally, to find a coral over 100 metres in size … there's no record of it."Sophie Kalkowski-Pope has been diving with her mother since she was a child. (ABC News: Conor Byrne)She said other contenders for the world's largest recorded corals included one off the Solomon Islands with a long edge of 34m, while a colony in Nusa Penida measured 71m across.She did not want to disclose the location of the latest discovery but said it would be monitored and managed by the Great Barrier Reef Marine Park Authority."We have passed that information on to … the managing authority for the Great Barrier Reef and it is in their jurisdiction and we're passing on the stewardship of that site to them," she said.The coral is in a secret location off Cairns. (Biopixel: Richard Fitzpatrick)She described the area as "tidally dominated"."Which we think is actually why this area has remained undiscovered for so long, because it's quite difficult to dive there," Ms Kalkowski-Pope said.Centuries-old discoveryThe Australian Institute of Marine Science (AIMS) applauded the pair's find, which research scientist Mike Emslie estimated to be "at least" a couple of hundred years old."Kudos to them for going out and measuring it and getting … pretty detailed measurements," he said."This kind of report is only a good thing for raising the profile of the reef."Without knowing the site's exact location, Dr Emslie said he could not confirm whether the reef was one AIMS had already surveyed."If it's not the same coral, that's even better news that there's another vast Pavona colony out there," he said."It indicates that these large, long corals are still standing up in the face of repeated acute disturbances like mass coral bleaching, cyclones and crown-of-thorns starfish."Measurements reveal the coral is 111m long and 60m wide, about the area of a soccer field. (QUT: Serena Mou)James Cook University marine scientist Allison Paley believed the "quite impressive" colony was undiscovered."I think what's equally likely, possible, is that we just also haven't discovered a lot of equally large corals that are on reefs around the world," she said.She praised the citizen scientists as researchers' "eyes on the ground"."This is just a classic example of the good that can come from these types of developed plans, these citizen science plans or programmes," she said.Sophie Kalkowski-Pope says the coral is an "absolutely stunning ecosystem and hotspot of life". (Biopixel: Richard Fitzpatrick)Meanwhile, Ms Pope said her role in the discovery was still sinking in.She recalled being stunned when she first saw it."The reason you go and do these things is because of our curiosity and wanting to contribute to a storehouse of knowledge," Ms Pope said."Possibly one of the things that's contributed to its health has been its location and its depth, where it's protected from a lot of bleaching events."