Scientists have discovered 64,000 square miles of heat-resistant coral reefs in 71 countries that could help protect the world’s oceans for decades.

An international team of scientists has mapped more than 64,000 square miles of coral reefs that can withstand extreme heat stress. The findings provide a vital plan to save marine life at a time when the world’s oceans are experiencing the worst bleaching crisis ever recorded.The study used artificial intelligence to analyze decades of environmental data. Artificial intelligence has identified specific underwater reserves in 71 countries and 100 territories. These areas have unique natural features that protect coral ecosystems, insulate them, or help them recover from marine heat waves.The research was presented at the Our Ocean Conference in Mombasa, Kenya, and published on the EcoEvoRxiv preprint server.

The findings challenge the prevailing scientific belief that coral reefs cannot be saved. Instead, new maps show exactly where governments should spend conservation money to protect marine life.“Coral reefs are often framed as ecosystems that are beyond the scope of conservation,” study co-author Emily Darling, director of coral conservation at the Wildlife Conservation Society, said at the conference. “This research shows otherwise.”

Use computers to find climate reserves

Coral reefs cover only 1 percent of the ocean floor but support a quarter of marine life. They are vital to the global food supply and protecting coasts from storms. Their biggest threat is rising water temperatures, which cause mass bleaching.When seawater becomes too warm, corals expel the tiny, colorful algae that live within them. This strips coral reefs of their main food source. It leaves them white-boned, extremely stressed, and likely to die of starvation or disease.To find habitats that can survive this heat, researchers identified three types of natural refuges, known as climate refugia:

Darling and her team trained the AI ​​model to search for these three types of reserves. They fed the computer nearly 45,000 coral observations recorded since 1960. The system looked at 42 separate environmental factors, including water chemistry, temperature changes, and local human activity.The AI ​​model evaluated global maps to predict coral health for 2050. The results showed that these resilient corals are highly concentrated. About 61% of these safe areas are located in the waters of only five countries: Australia, the Bahamas, Cuba, Indonesia, and the Philippines.The models also discovered entirely new, highly resilient reef areas in Belize, Nicaragua and the Turks and Caicos Islands.

This expands on data from the 2018 “50 Corals” study, which was the first major effort to find heat-tolerant corals.

A plan to finance targeted conservation

Finding these specific areas provides a clear plan for environmental groups. This is especially useful for small island nations that do not have the money or resources to fully protect their waters.“Climate-resistant corals are not spreading evenly,” study co-author Joseph Maina, an ecologist at Macquarie University in Australia, said at the conference.

“Countries need to understand…those differences so that when they plan where future conservation investments should go, they take into account this unequal distribution.”Independent scientists welcomed the accuracy of the new data. They point out that it changes the focus from merely recording the destruction of the oceans to actively saving them.“This study reinforces decades of work on the resilience of coral reefs to climate change,” says David Obora, a marine ecologist and head of the Intergovernmental Platform on Ecosystem Services for Biodiversity, who was not part of the research team. “It focuses attention on the critical question: Will climate refuges make up 10 percent, 1 percent, or even less of the reef’s former range?”However, local environmentalists in these newly discovered safe zones say the findings should be treated with care.

Alizee Zimmerman, executive director of the Turks and Caicos Islands Coral Reef Fund, wants to examine the data more closely, because her region lacks long-term monitoring. She warned that good news should not make governments feel complacent.“The narrative that Caribbean coral reefs are simply ‘dead’ is inaccurate and could be detrimental to progress made on coral restoration and protection initiatives in the region,” Zimmerman said.

“However, it would also be disingenuous to say that they are thriving.”

Background of global devastation

The discovery of these pockets of elasticity comes at a time of great urgency. According to a report by the National Oceanic and Atmospheric Administration (NOAA) and the International Coral Reef Initiative, more than 80 percent of the world’s coral reefs have experienced bleaching-level heat since 2023. That makes this the worst global bleaching event in history.Mass die-offs have struck the tropics. Florida’s coral reefs suffered extreme heat in 2023, causing 100 percent bleaching across the Florida Keys. In 2024, Australia’s Great Barrier Reef faces catastrophic bleaching. Serious damage was also recorded in the Persian Gulf, the Red Sea, and large parts of the Caribbean.The current crisis has surpassed the previous record set between 2014 and 2017, when 70 percent of the world’s coral reefs were exposed to extreme heat.

Melanie McField, founder of the Healthy Reefs for Healthy People initiative, described the frightening sight of heat-damaged corals.“There’s usually an absence of flapping fish and an absence of vibrant colors on the reefs,” McField said. “It is a gray pallor and stillness in what should be a bustling, vibrant coral landscape.”

Navigating uncharted waters

Because the current marine heatwave is still occurring, scientists don’t know when water temperatures will drop enough for coral reefs to recover.“We may never see the thermal stress that causes bleaching drop below the threshold that triggers a global event,” warned Mark Eakin, corresponding secretary of the International Coral Reef Society. “We are looking at something that will completely change the face of our planet and the ability of our oceans to sustain lives and livelihoods.”Britta Schafelke, a researcher at the Australian Institute of Marine Science, agrees that the sheer scale of the heatwave is taking marine ecosystems into completely uncharted waters.However, supporters of the new mapping study point out that coral reefs have survived major extinctions throughout Earth’s history. If these designated safe zones are protected from overfishing and pollution, coral reefs could eventually spread and repopulate other areas.“The ancestors of today’s corals survived the asteroid impact that wiped out the dinosaurs on land and a lot of creatures in the sea,” says Jörg Wiedenmann, a marine biologist at the University of Southampton.

“So, if we can reduce ocean warming, there is always a chance for coral reefs to recover in.”In the long term, saving these newly designated areas depends on global political action to reduce greenhouse gas emissions. Valeria Pizarro, a senior coral reef scientist at the Perry Institute for Marine Science, stressed that world leaders must invest heavily in clean energy and reduce the use of fossil fuels to give these reserves a real chance.However, these protections face immediate political hurdles in the United States, where the Trump administration has moved to increase fossil fuel production and limit clean energy initiatives. Coral researchers view these policy changes as a direct threat to global conservation.“Removing these protections would have devastating consequences,” Eakin said.