In recent months, news outlets around the world have been racing to spread the word about the discovery of the largest discovered coral colony in all the world’s reefs. The coral, a massive colony of Pavona clavus, was discovered off the coast of the Solomon Islands in the South Pacific. This colony is massive, measuring 34 meters wide, 32 meters long, 5.5 meters high, with a circumference of 183 meters, and is estimated to be roughly 300 years in age. At the time of its discovery in October of 2024, this coral was three times larger than the previous record-holding colony – so large, in fact, that it can be seen from space. For context, at its widest dimension, a coral this size surpasses the length of the largest recorded blue whale, which measured 33.5 meters (110 feet) long.
The discovery of this supercolony in the Solomon Islands seems to have triggered a surge of enthusiasm amongst coral reef researchers to search for and document large colonies within their own jurisdictions. In conjunction with Ocean Gardener (a coral conservation NGO founded by Vincent Chalias), a group of Indonesian marine scientists stumbled upon a coral colony in early December that they believe could surpass the record held by the Solomon Islands’s Pavona. Initial measurements of this coral colony come in at 58 meters wide, 71 meters long, and 10 meters high. If the coral is truly as large as these initial measurements suggest, the colony’s widest dimension will surpass the length of most models of Boeing 747 jets (70.6 meters)
Even a far-away wide-angle shot can only capture part of the colony in the frame due to its expansive size. (Image Credit: Ocean Gardener)
This newest largest coral has been identified as Galaxea astreata, although it has been misspelled as “Galatea Astreata” in many news publications. This species is a common coral that is widespread throughout Indo-Pacific reefs, where it forms colonies that regularly exceed 2 meters in diameter. Galaxea astreata is regularly distinguished from its more common sister species G. fascicularis, due to its near-perfect circle corallites that are widely spaced apart and relatively few number of exsert septa.
Galaxea astreata (left) compared to Galaxea fascicularis (right). The tentacles of G. astreata rarely extend during the day, unlike those of G. fascicularis. (Image Credit: Damien Brouste via inaturalist.org/observations/141138239 and inaturalist.org/observations/57428102)
Assuming that both colonies are roughly hemispherically ellipsoidal in shape based on typical growth patterns for both species, some quick geometric calculations allow us to estimate the surface area and volume of both corals. Using the formula SA = 4(ab)1.6 + (ac)1.6 + (bc)1.631/1.6 where a and b are interchangeable dimensions for length and width and c represents the height of the colony, we arrive at a very rough gross surface area values of 7,360.98 square meters (m2) for the Pavona and 27,696.71 m2 for the Galaxea. This means that the new largest coral colony is almost 4 times larger than the previous largest coral, which in turn was already 3 times larger than its predecessor.
Divers work to measure the a portion of the Galaxea supercolony using a transect tape. (Image Credit: Ocean Gardener)
It’s exciting and encouraging to see new reports of these incredibly large coral colonies, many of which are several hundreds of years old. Although most corals have an “indeterminate” lifespan, surviving intact for centuries is no small feat for these primordial anthozoans and a testament to their resilience under proper conditions. However, wiith each passing day our oceans become increasingly inhospitable and we continue to lose more and more corals. Examples of super colonies like the ones found in the Solomon Islands and Indonesia are all the more reasons to support science-based conservation efforts to protect and preserve our wild reefs, lest we want to lose these ancient corals forever.
More information about the incredible work that Ocean Gardener does can be found on their website: www.oceangardener.org
