Coral Bleaching Awareness Month: Giving Coral Reefs a Chance to Recover

by Luz Veronica Delvasto Algarin • September 22, 2026

or hundreds of millions of years, coral reefs have supported life in our oceans. Although they cover less than 1% of the ocean floor, they provide habitat for at least 25% of all marine species. They also support people around the world by sustaining fisheries and tourism, providing food and livelihoods, and helping protect coastlines from waves and storms.

But coral reefs are under increasing pressure. Pollution, overfishing, coastal development, physical damage, and increasingly warm ocean temperatures can all affect reef health. One of the most visible signs that a coral reef is under stress is coral bleaching.

This September, in recognition of Coral Bleaching Awareness Month, we’re taking a closer look at what happens when corals bleach, why bleaching matters, and what scientists around the world are doing to better understand, protect, and restore coral reefs.

Before and after coral bleaching at Lizard Island on Australia’s Great Barrier Reef, showing the dramatic changes that can occur when heat-stressed corals lose their symbiotic algae.

PHOTO COURTESY OF Richard Vevers / The Ocean Agency / Ocean Image Bank

What is coral bleaching?

Corals may look like rocks or plants, but they are actually colonies of tiny animals called polyps. Living within their tissues are microscopic symbiotic algae called zooxanthellae. These algae provide corals with much of the energy they need to survive and give many corals their color.

When corals experience environmental stress, this important relationship can break down. The algae leave the coral’s tissues, revealing the white skeleton underneath. This is what we call coral bleaching.

Bleaching is a general stress response and can be caused by several environmental changes, including unusually high or low water temperatures, changes in salinity, excessive sunlight, pollution, and exposure during extreme low tides.

Large-scale bleaching events, called mass blaeachings, are most often associated with severe or prolonged heat stress, including marine heatwaves that affect reefs across large regions.

When a coral bleaches, it loses its primary source of energy. This leaves the coral weakened and more vulnerable to disease and other stressors. However, a bleached coral is not necessarily dead. If conditions improve, the algae can return and the coral may recover. If stressful conditions continue for too long, or another disturbance occurs before the coral has had time to recover, the coral may die.

That recovery time is becoming increasingly important for the future of coral reefs.

Fluorescing corals during a bleaching event in Okinawa, Japan. While bleached corals often appear white, some produce vivid fluorescent pigments that act like a natural sunscreen, helping protect the stressed coral from excess sunlight.

PHOTO COURTESY OF The Ocean Agency / Ocean Image Bank

What does this mean for corals?

The past several years have been particularly difficult for reefs around the world. From 2023 through 2025, the fourth global coral bleaching event exposed an estimated 84% of the world’s coral reef area to bleaching-level heat stress, making it the largest global bleaching event on record.

This year, coral reefs face an additional concern as a “super” El Niño is underway and continues to intensify. El Niño is a naturally occurring climate pattern that typically develops every two to seven years, when waters in the central and eastern equatorial Pacific become unusually warm. These changes in ocean temperatures can influence weather and ocean conditions around the world.

For coral reefs, this is particularly concerning. El Niño can contribute to unusually warm ocean temperatures and prolonged heat stress—conditions that can trigger widespread coral bleaching. When these events occur on reefs that are already recovering from previous disturbances, they can further reduce the time corals have to recover before being stressed again.

The last exceptionally strong El Niño, in 2015–2016, coincided with the third global coral bleaching event, which caused widespread bleaching and coral loss across multiple ocean basins. Scientists will be closely watching reefs in the coming months to understand how this year’s El Niño affects ocean temperatures and coral health.

This NOAA animation shows the development of El Niño in the tropical Pacific Ocean, with red indicating warmer-than-average sea surface temperatures and blue indicating cooler-than-average temperatures, from January 1 through June 8, 2026.

Image credit: NOAA Satellites

The latest global assessment of coral reefs shows what repeated disturbances can mean over time.

The *Status of Coral Reefs of the World: 2025* report provides a global assessment of coral reef health using decades of monitoring data, including data contributed by the Living Oceans Foundation from the Global Reef Expedition. PHOTO COURTESY OF GCRMN

Released in August, the Status of Coral Reefs of the World: 2025 report from the Global Coral Reef Monitoring Network (GCRMN) is the most comprehensive assessment of global coral reef health ever produced. The report draws on more than 21 million observations from nearly 37,000 reef sites around the world to examine changes in coral cover over more than four decades.

The Khaled bin Sultan Living Oceans Foundation contributed data collected during the Global Reef Expedition to this global assessment, helping build a more complete picture of how reefs are changing around the world.

The findings are concerning. Global hard coral cover has declined over the past several decades, with major losses associated with global bleaching events.

But the report also contains an important message of hope: coral reefs can recover when given the chance.

Following the third global bleaching event, global hard coral cover increased by approximately 6% between 2017 and 2019. This recovery showed that reefs retain a natural capacity to rebound after disturbance when conditions improve and enough time is available.

The challenge is that the time between major disturbances is getting shorter, leaving reefs with less opportunity to recover.

While surveying reefs on the Global Reef Expedition mission to the Chagos Archipelago in 2015, Living Oceans Foundation scientists watched as the reefs began bleaching before their eyes.

PHOTO BY THE KHALED BIN SULTAN LIVING OCEANS FOUNDATION

Scientists from the Living Oceans Foundation have witnessed coral bleaching unfold in real time.

Our award-winning documentary, Coral Reefs: Trouble in Paradise, follows an international scientific team conducting research in the Chagos Archipelago during the Global Reef Expedition. Located in the central Indian Ocean, these remote islands were home to some of the healthiest coral reefs our scientists had encountered.

During the research mission, however, unusually warm waters caused widespread coral bleaching. Within weeks, scientists watched thriving reefs turn white.

Their experience showed just how quickly bleaching can transform a coral reef, and that even reefs in some of the most remote places on Earth are vulnerable to large-scale environmental changes.

The research also provided reasons for hope. Understanding which reefs survive, how they recover, and what conditions help them remain resilient gives scientists and managers valuable information that can help guide future conservation efforts.

Coral Bleaching Awareness Month

Coral Bleaching Awareness Month was created by the Coral Reef Alliance (CORAL) to raise awareness and understanding of coral bleaching and what it means for the future of coral reefs.

Now observed in September, the campaign brings together scientists, conservation organizations, reef managers, communities, and ocean advocates around the world to share research, educational resources, and stories from coral reefs.

The *Coral Bleaching: Reefs at Risk* Activity and Coloring Book uses engaging activities, illustrations, and accessible science to help young learners understand coral bleaching, why it happens, and what it means for coral reefs.

Awareness matters because the effects of coral bleaching extend far beyond individual coral colonies.

Healthy coral reefs provide habitat, food, and nursery grounds for thousands of marine species. They also support fisheries, tourism, and coastal communities while helping reduce the impacts of waves and storms. When coral populations decline, the complex ecosystem built around them can also suffer.

Education is an important part of protecting these ecosystems. That’s why the Living Oceans Foundation created Coral Bleaching: Reefs at Risk, the first book in our Reefs at Risk Activity and Coloring Book series.

Designed for young learners, the book introduces children to coral reefs through coloring pages, activities, and accessible science. Students learn how corals live, why bleaching happens, and why healthy reefs matter to people and marine life.

Bleached and dead corals on the Great Barrier Reef during the 2016 bleaching event. While bleached corals can survive and recover, prolonged heat stress can lead to coral death—underscoring why reefs need time and favorable conditions to recover between disturbances.

IMAGE COURTESY OF The Ocean Agency / Ocean Image Bank

Helping reefs recover

The global scale of coral bleaching can make the challenge seem overwhelming. But there are meaningful ways to improve conditions for reefs, particularly by reducing the local pressures they face.

Protecting water quality, reducing pollution and marine debris, managing fisheries sustainably, and preventing physical damage to reefs can all help create better conditions for coral survival and recovery.

People visiting coral reefs can also help. Divers and snorkelers should avoid touching or standing on corals, and boaters should use moorings when available or anchor safely away from coral reefs. Communities can support efforts to improve water quality, reduce marine debris, and protect coastal habitats.

Scientific monitoring is equally important. Long-term datasets help scientists understand which reefs are changing, which are recovering, and why some reefs appear more resilient than others. That knowledge can help reef managers make informed decisions about where and how conservation efforts can have the greatest impact.

A healthy coral reef in French Polynesia, surveyed during the Global Reef Expedition. Coral reefs can be remarkably resilient when given the time and conditions they need to recover from disturbance.

PHOTO BY Michele Westmorland/iLCP

Beacons of hope

Around the world, scientists, conservation organizations, and local communities are also developing and testing new ways to help damaged reefs recover.

In Indonesia and the Maldives, the Mars Coral Reef Restoration Program has restored damaged reef areas using structures designed to stabilize degraded reef substrate and provide a foundation for coral growth. The program has planted tens of thousands of corals across restoration sites while researchers continue to study how restored reefs develop over time.

In Australia, researchers at Great Barrier Reef Innovations are testing innovative ways to give young corals a better chance of survival on the Great Barrier Reef. Protective devices are being used to shield vulnerable juvenile corals from predators, while scientists have also successfully raised “cryo-born” corals from reproductive material preserved through cryopreservation, an approach that could help safeguard coral genetic diversity for the future. Researchers at the Australian Institute of Marine Science, are also studying heat-tolerant corals and other approaches that could help reefs withstand future bleaching events.

In Belize, Fragments of Hope shows what sustained, community-led effort can do over time. The organization has spent nearly two decades restoring coral reefs, maintaining coral nurseries, propagating genetically diverse corals, and helping restore coral cover at sites including Laughing Bird Caye National Park, where live coral cover has increased from 6% to 60%.

Other organizations are helping connect these individual efforts. The Coral Restoration Consortium serves as a worldwide hub, linking scientists, practitioners, and local communities to share best practices, tools, and innovations, and its interactive restoration map offers a real-time view of where restoration efforts are happening and who’s leading them. Meanwhile, SECORE International is advancing techniques that use sexual coral reproduction to increase genetic diversity and develop restoration methods that can be applied at larger scales.

These efforts are promising, but coral restoration alone cannot address all of the pressures facing reefs. Instead, restoration is one tool among many—including monitoring, effective reef management, improved water quality, education, and reducing local stressors—that can help give reefs a better chance to survive and recover.

Clownfish shelter in a bleached anemone in Raja Ampat, Indonesia. Like corals, anemones can lose their symbiotic algae when stressed, causing them to bleach and potentially affecting the animals that depend on them.

PHOTO Courtesy of Dani Escayola / Ocean Image Bank / The Ocean Agency

There is no single story about the future of the world’s coral reefs.

Some reefs have experienced severe losses. Others have remained relatively stable. Still others have demonstrated a remarkable ability to recover following disturbance.

The latest global research reminds us why that variation matters.

Coral reefs are dynamic ecosystems, and they still retain the capacity to recover. Following the third global bleaching event, reefs around the world regained some of the coral cover they had lost. But recovery takes time—and increasingly frequent disturbances are shortening that window.

This Coral Bleaching Awareness Month, there are plenty of reasons to be concerned about the future of coral reefs. But there are also reasons for hope.

Scientists are monitoring reefs and improving our understanding of how they respond to disturbance. Reef managers and communities are working to reduce local pressures. Conservation organizations are testing new restoration techniques. Educators are helping the next generation understand why these ecosystems matter.

Together, these efforts can help create the conditions coral reefs need to withstand disturbance and recover.

Coral reefs can recover. Our challenge is to give them the chance.

Turtle over partially bleaching coral, Raja Ampat, Indonesia Credit: Dani Escayola / Ocean Image Bank

Coral bleaching in American Samoa, 2015 Credit: Richard Vevers / Ocean Image Bank

Great Barrier Reef, Australia, 2017 Bleaching Credit: The Ocean Agency / Ocean Image Bank

Blue fluorescing coral in New Caledonia (2016) Credit: Richard Vevers / The Ocean Agency

Great Barrier Reef, Australia 2016 Bleaching Credit: The Ocean Agency / Ocean Image Bank

Coral bleaching on Acropora branch Credit: The Ocean Agency / Ocean Image Bank

Corals we surveyed in the Chagos Archipelago turned bright cotton-colored shades of pink, blue, and yellow in the bleaching process in an effort to protect themselves from the sun’s harmful rays.

Corals in the process of bleaching in the Chagos Archipelago.

Bleached anemones on a reef in the Chagos Archipelago

Fluorescing reef, New Caledonia (2016) Credit: Richard Vevers / The Ocean Agency