The researchers of the group Pristine Seas from the National Geographic Society they discovered almost by chance last October the largest coral in the world identified so far. Located off the Solomon Islandsin the’Pacific Ocean southern, the colony is 32 meters long, 34 meters wide and 5 meters high: it occupies an area of 1088 m²equal to almost three times that of a basketball court standard. It’s as big as it could be seen from space!
How the world’s largest coral was discovered
The discovery occurred during an expedition aimed at studying and documenting the coral systems of the Solomon Islands, known to host one of the greatest biodiversity in the worldhence the name Coral Triangle or Coral Triangle. The mega-coral, with a width of approximately 34 meters and a length of 32 meters, is located 300 nautical miles offshoreDuff Island, to a depth of just over 12 meters. It’s about the largest colony ever discoveredfar surpassing the previous record held by coral”Big Momma”, which has a circumference of 41 meters and a height of approx 6.5 meters. The latter is found in National Marine Sanctuary of American Samoaa protected area off the coast of Samoa Islands.
Despite its remarkable size, the colony remained surprisingly unnoticed for years. The locals, in fact, have often confused the shadow of the coral visible from the surface of the water for a rock mass or the remains of a sunken boat.”His discovery was truly fortuitous” he says Molly Timmerslead scientist of the expedition, as reported on the National Geographic page. “It was found the night before we moved to another section”.
The characteristics of mega-coral
Corals are animals belonging to the group Cnidaria. Most of the structures we call “coral” actually are colonies composed of hundreds or thousands of small organisms soft-bodied, called polypsoften as large as a 5 cent coin of euros. Each polyp secretes an external skeleton of hard limestone, called coralitewhich attaches itself to bedrock or the dead skeletons of other polyps. Numerous neighboring colonies form the coral reefs or reef. The recently discovered mega-coral in the Pacific is estimated to consist of almost a billion polyps genetically identical, working in unison within the colony as if they were a single organism.
The organisms that form this colony belong to the species Pavona clavuscommonly known as “scapula coral” due to the shape that resembles that of the shoulders. The colony mainly has a brown color, enriched by scattered patches of yellow, red, pink and blue. Based on the height, equal 5.5 metersresearchers estimated that the mega-coral has an age between 300 and 500 years. This is because corals tend to grow vertically, with individual polyps rising from the skeleton and depositing new calcium carbonate in the portion below, creating a new base on which to rest. The growth rate of corals varies depending on the species and environmental conditions, from a minimum of 7.6 mm per year beyond 10 cm per year.
Organisms at risk
Although the newly discovered mega-colony is in good healthresearchers from the Pristine Seas group expressed concern about the many threats these organisms face globally, including bottom trawling and global warming. The latter is the main cause of the disappearance of over 40% of the world’s coral systems over the last 30 years.
“Our climate crisis is making the ocean warmer and more acidic, and this is destroying corals around the world, including mega-coral“said Enric Sala, explorer and scientist with the National Geographic Society.
