How is the latest research trying to protect coral from global warming?
Around the world, coral reefs are under threat. To protect them, scientists and NGOs are exploring several avenues: organic tissue imitating the structure of corals, investigation of the survival strategies of different species, reproduction of coral in the laboratory. Among the most endangered underwater species, coral reefs top the list. Essential to biodiversity and human health, coral reefs are put to the test by sea heat waves, which are becoming more frequent due to climate change. Rising water temperatures lead to acidification of the oceans, which causes significant heat stress for corals (which ultimately leads to bleaching, or the death of these reefs). According to a study published on February 1 in the journal PLOS Climate by researchers at the University of Leeds, 99% of the world’s corals will not withstand climate change. One of the most urgent solutions to protect corals is of course to drastically reduce greenhouse gas emissions.
Study different coral species to better understand them
But according to research by scientists at the University of Leeds, meeting the most ambitious goal of the Paris Agreement (keeping global temperatures below 1.5°C) will not be enough to ensure the survival of long-term corals. “Promoting adaptation to higher temperatures and facilitating migration will instead be necessary to ensure the survival of coral reefs,” say the authors of the book.
This is a point of view that echoes the conclusions of several scientific studies carried out in recent years around the world to ensure the protection of corals. Biologists from the University of Wisconsin-Madison in the United States published a study in early 2022, in which they studied the skeletal structure of three different species of coral to determine which is most resistant to the phenomenon of ocean acidification .
Scientists have discovered that this resistance could be linked to the rate of crystallization of the coral skeleton, composed of amorphous calcium carbonate. The faster the rate of crystallization, the more likely it is to resist ocean acidification.
One of the other avenues studied by scientists to increase the resilience of coral reefs is their microbiome. Researchers at Penn State University have identified microbes potentially capable of enhancing coral species’ responses to heat stress, suggesting this could be an area that could help them survive.
Preparatory work is underway to fund rescue plans to protect coral reefs. A solution that consists above all in protecting underwater coral areas from human activities that could harm them, such as overfishing or mass tourism. In 2021, Thailand decided to ban chemical components of sunscreens toxic to marine life, like Palau and Hawaii.
Another angle of action consists in covering certain reefs with biodegradable organic fabrics imitating the composition of corals. An experiment is currently underway in Guadeloupe. The idea is to create nets intended to offer a refuge to the coral eggs to fix them and protect them from predators. The NGO Ocean Quest Global has developed a method of cuttings to rehabilitate the natural habitat of the reefs.
Meanwhile, a recent exploratory mission supported by Unesco offers hope. Divers have discovered very rare coral reefs, submerged more than 30 meters deep on the island of Tahiti. What was so special about them? They turned out to be in perfect health.
One of the reasons why these reefs have been spared by global warming could be related to the depth at which they are submerged. Temperature sensors have been placed in the area of the corals concerned, in order to better understand how and why these reefs have resisted climate change, as well as in the hope of finding others.
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