Polynesia, 'super corals' capable of withstanding heat discovered
Environment — di Andrea Barolini
A scientific mission at an atoll in French Polynesia has led to the discovery of corals that survive in very warm waters.
Polynesia, 'super corals' capable of withstanding heat discovered
A scientific mission at an atoll in French Polynesia has led to the discovery of corals that survive in very warm waters.
It is called Tatakoto and it is an atoll located in the Tuamotu archipelago, in French Polynesia, more than a thousand kilometres from Tahiti. Here – or rather, from here – a glimmer of hope for the conservation of coral reefs around the world may be born, threatened as they are by global warming, rising ocean water temperatures and ocean acidification.
The "1 Ocean" mission supported by the French Cnrs and Unesco
A group of scientists has in fact discovered what have been immediately dubbed "super corals". This is, at least, the hypothesis put forward by researchers at the French laboratory Criobe, run by the Cnrs (the French equivalent of Italy's National Research Council). Since 2021 they have been participating in an expedition, the "1 Ocean" mission, also supported by Unesco and aimed precisely at understanding how certain coral species manage to thrive even in conditions that, until now, have been considered unsuitable for their survival.
Since 2021, scientist Laetitia Hédoouin and underwater photographer Alexis Rosenfeld have been analysing the reef, eventually documenting the discovery. The corals in question have survived not only intense ocean warming events, but also extreme temperature fluctuations — which raises great hope for the conservation of ecosystems that are vital to biodiversity protection worldwide.
A stretch of sea theoretically inhospitable to corals
The stretch of sea in which the analysis was carried out is particularly well-suited to the researchers' objectives. As explained by Rosenfeld, "its peculiarity is that it resembles almost a closed lagoon. In other words, there is no ebb and flow of thousands of cubic metres of water as in other areas. As a result, the water stays put and remains very warm, at more than 30 degrees Celsius. Nevertheless, we found that the corals inside survive, and even appear to be in good health."
The discovery is, in itself, extraordinary — especially in a context where, due to climate change, almost all of the Earth's coral reefs are under threat. But the researchers want to understand whether the case of Tatakoto's "super corals" is an isolated one, or whether it is the result of a genetic transformation that occurred precisely in order to adapt to new conditions.
Cuttings transplanted elsewhere to determine whether the corals have undergone genetic changes
It is for this reason that, as part of the mission, some cuttings were taken from the Polynesian atoll and then planted in another archipelago, that of Moorea, which has more "classic" characteristics. Should the corals manage to survive in a more "standard" habitat, it could be hypothesised that they have indeed learned to cope with climate warming.
At that point, one could also envision a kind of reef reforestation: "These corals, and this lagoon," researcher Hédouin explained, "could become a source of super corals, which could be transported to the archipelagos where heatwaves are having a major impact." Further studies, analyses and confirmation will therefore be needed to understand the full extent to which the discovery might truly represent a breakthrough.