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The Coral Triangle Day (June 9) is a celebration of the Coral Triangle, the world’s epicentre of marine biodiversity. A marine area located in the western Pacific Ocean, the Coral Triangle countries include Indonesia, Malaysia, the Philippines, Papua New Guinea, Timor Leste and Solomon Islands. 

What is the Coral Triangle and Why is it Important?

The Coral Triangle occupies just 1.5% of the world’s total area, but represents 30% of the world’s coral reefs. The area, covering over 130 000 sq km, has nearly 600 species of reef-building corals – 75% of the world’s coral species, and is home to six of the world’s seven marine turtle species and more than 2,000 species of reef fish. This makes the Coral Triangle one of the largest ocean habitats in the world. 

Whales, dolphins, porpoises, dugongs and whale sharks feed, breed and migrate in these waters. The area also supports large populations of commercially important tuna; over 120 million people live in the Triangle and rely on it for food, income and protection from storms. Tuna spawning and nursery grounds support a multi-billion dollar industry, while the tourism industry associated with the Triangle is valued at over USD$12 billion annually. 

Healthy reefs act as natural barriers that soften the blow from typhoons, storm-generated waves and tsunamis. A 2018 study found that damage to coastal communities in the Triangle caused by flooding events would nearly double without and  the coral reefs. Additionally, without the reefs, Malaysia, Indonesia and the Philippines would see the costs of flooding events tripled; the reefs that encircle these countries could save, on average, more than USD$400 million each year. 

To delineate the Coral Triangle, scientists and conservationists looked at high species biodiversity of coral and reef fish, and habitat diversity, as well as currents. 

The Coral Triangle is generally more resilient against the climate crisis because of the complexity in the region. Research shows that the persistence of these stable conditions over the last 30 million years may have given rise to the region’s biodiversity.

Because it is less exposed than places like the Great Barrier Reef, there’s a chance the Coral Triangle could withstand some of the more dire impacts of the climate crisis.

There are many theories as to why reefs in this region are so successful, such as the fact that the Coral Triangle consists of a wide range of habitats, from volcanic islands to mangrove forests, which forced the species to adapt to the geographically complex reef system. Other reasons include the fact that the Coral Triangle sits between the Indian and Pacific oceans; marine species from both bodies of water colonise parts of the reef system where the ocean basins overlap, increasing the number of species found in the region, and another reason is that as geographic area increases, the risk of extinction decreases. If a species inhabits a large area, there’s less of a chance an organism will go extinct if something happens to a part of the reef where that organism lives. Finally, many species originate in isolated archipelagos in the Indian and Pacific oceans, such as Hawaii or the Maldives, and then are swept into the Coral Triangle by these currents. Once in the Coral Triangle, these species mix with native species, and eventually form new species. 

You might also like: Seagrass Could Replace Forests As the Ideal Carbon Sink

what is the coral triangle?
An illustration showing the countries that make up the Coral Triangle (Source: WWF). 

Threats to the Coral Triangle 

Overfishing and methods of harvesting fish and other resources, such as cyanide poisoning and dynamite fishing, are unsustainable at current levels and place this vitally important region at risk of breakdown, in addition to rising ocean temperatures that are threatening its coral reefs and the distribution of fish. Blasting destroys over 200 sq feet of coral reef at a time, while cyanide stuns fish without killing them, leaving them unable to move and easy to catch. Bycatching is also an issue, where non-target fish species are caught.

When large, predatory fish are sustainably caught, the reef can rebound. Often though, the area’s largest predators are pulled from the reef in high numbers, shrinking their populations and allowing destructive fish populations to weaken the coral reef ecosystem. 

Coral reefs cannot survive if the water keeps warming; corals rely on algae living inside them to supply them with food. These algae, which give the corals its colours, die if the water gets too hot. The loss of this algae leaves the coral bleached. 

Warming oceans also absorb more carbon dioxide. CO2 alters the ocean’s pH balance, which makes it more acidic and toxic. Shellfish and corals are particularly vulnerable to ocean acidification because it interferes with their ability to form hard skeletons.

Additionally, plastic pollution is threatening the reefs. Animals consume small pieces of plastic, and these plastics sometimes act as vectors for disease, spreading contagions like ‘white syndrome’ from sick to healthy corals. 

What Can Be Done to Preserve the Coral Triangle?

In Papua New Guinea, mangrove nurseries have been started, which help to protect coastlines from impacts such as sea-level rise. 

In 2009, leaders from the six nations making up the Coral Triangle launched “The Coral Triangle Initiative on Coral Reefs, Fisheries and Food Security” to sustain the region’s marine and coastal resources by addressing issues such as food security, climate change and marine biodiversity. The group recognises the detrimental impacts of the climate crisis on the Coral Triangle and they have developed an action plan specific to the area. The plan requires, among other things, putting in place effective adaptation strategies for coastal, investing in climate change vulnerability assessments and improving the resilience of coastal communities.

Featured image by: Thái Viết Hoàn

A new study states that it is not too late to save our planet’s coral reefs before they go extinct.

Coral Reef Extinction Facts

Coral reefs host a quarter of the Earth’s marine biodiversity and support livelihoods of more than half a billion people. But, the planet has already lost half of its coral reefs over the last three decades, and more than 90% of them might become extinct by 2050.

Corals face a number of threats including overfishing, diseases, and pollution, while the biggest of them all is climate change. The world’s largest coral reef system- the Great Barrier Reef, which is visible even from outer space- has lost half of its coral in the past two years because of extreme heat stress from global warming.

While conservationists around the globe are grappling with how to preserve the last surviving ‘underwater rainforests’, the most comprehensive study on coral reefs published last week has suggested a few ways to save them. As part of the research, an international group of 80 scientists surveyed more than 2,500 coral reef systems across 44 countries to determine how to protect them in the face of extensive damages caused by human activities and global warming.

“The good news is that functioning coral reefs still exist, and our study shows that it is not too late to save them,” said Emily Darling, the lead author of the study and a Wildlife Conservation Society (WCS) scientist leading the global coral reef monitoring program. “Safeguarding coral reefs into the future means protecting the world’s last functioning reefs and recovering reefs impacted by climate change. But realistically — on severely degraded reefs — coastal societies will need to find new livelihoods for the future.”

Examining coral abundance in the Indian and Pacific oceans, they found that many of the reef systems were full of complex species that created distinctive structures and were functioning in spite of deadly marine heatwaves in recent years.

Heatwaves had affected many coral reefs during the El Niño event between 2014 and 2017. But 450 reefs in 22 countries survived in protective cool spots. The scientists believe those areas should be the focus of urgent protection and management efforts. Previously, the Indo-Pacific reefs were also hit by mass coral bleaching and heat stress in 1983, 1998, 2005 and 2010, before the world’s most intense, longest and largest bleaching event between 2014 and 2017.

You might also like: Artificial Corals: Improving the Resilience of Coral Reefs (part II)

A marine scientist gathering data on coral reefs in the waters of Fiji. Credit: WCS

How to save coral reefs?

The researchers outlined three conservation strategies to save the reefs: protect, recover, and transform. As part of the first strategy, the international network of coral reef conservation should focus on protecting functioning coral reefs found in East Africa to Southeast Asia, the Coral Triangle, and the Pacific. The second strategy is to promote rapid recovery of coral reefs impacted by the 2014-2017 coral bleaching event. To implement the third strategy, selected coastal communities around the world should be relocated to avoid dependence on reefs that are no longer functioning.

The scientists pointed out that strategic local management can help protect corals through tools such as marine protected areas, or other management restrictions that reduce threats and keep coral reefs above functional thresholds.

“While coral reef sustainability depends largely on reducing carbon emissions, identifying reefs that are likely to respond — or importantly, not respond — to local management is critical to targeting development and management strategies to build the well-being of the millions of people dependent on coral reefs across the globe,” said Georgina Gurney, study co-author from the ARC Centre of Excellence for Coral Reef Studies at James Cook University

The researchers also noted that limiting global temperature within two degrees Celsius over pre-industrial levels is the only way to ensure the survival of reefs.

“Saving reefs will require combining local and global efforts, such as reducing local dependence on reef fish to maintain a reef’s important functions while also reducing carbon emissions to keep warming below 1.5C,” said Tim McClanahan, co-author of the study and Wildlife Conservation Society senior conservation zoologist.

Gabby Ahmadia, director of marine conservation science at World Wildlife Fund and co-author of the study said that the study would help policymakers and conservationists make informed management decisions for coral reefs and the communities that rely on them before they go extinct.


Marine biologists call the Philippine Sea the ‘centre of the centre’ of aquatic biodiversity. However, with ongoing decimation, marine biodiversity in the Philippines is facing a bleak future. 

The Philippines and Marine Ecosystem Conservation 

Covering a major portion of the Coral Triangle, with more than 16800 sq km of coral reef, the Philippines is a global centre for marine biodiversity. Its central region, from Luzon to Mindanao, has more marine species per unit area than any other place on the planet. It is home to a unique plethora of seagrass, invertebrates, seaweeds, and marine mammals.

But the country is struggling to conserve its marine life in the face of overfishing, destructive fishing practices, and growing plastic pollution. These human activities coupled with climate change have led to an unparalleled decimation of its marine biodiversity.   

A study published in the Philippine Journal of Science reports that reefs in the country’s territorial waters are no longer in excellent condition, and that 90% are classified as either poor or fair. Another 2017 report by the United Nations predicted that all 29 World Heritage coral reefs, including one in the Philippines, will die out by 2100 unless carbon emissions are drastically reduced.

Decades of destructive practices like dynamite fishing, bottom trawling, and cyanide fishing have wreaked havoc in the Philippine Sea. An analysis by the University of British Columbia found that destructive fishing methods have been liberally used in the Philippines since the 1960s, with peaks in the 70s and 80s when national fishing policies shortsightedly encouraged higher yield from fish stocks with no regard for collateral side-effects. Although the authorities issued a ban in the late 90s, those fishing methods continue to be commonly practiced until this day.

Dynamite fishing– whereby explosives are detonated underwater killing all marine life within the radius of the blast–is the most common practice among local fishermen. The second most popular practice is cyanide fishing–a technique used to stun the fish by squirting sodium cyanide into water. Bottom trawling is used for large-scale fishing by commercial fishing vessels. 

You might also like: Conch and the Wider Problem of Unsustainable Fishing

Floating dead fish; the immediate aftermath of dynamite fishing.

In 2014, the European Union issued a yellow card to the Philippines warning that it would be banned from exporting to the bloc unless its fishing activities were strictly regulated. In response, the government introduced a new fisheries code that called for stricter measures against destructive methods. But it has produced mixed results due to the absence of serious enforcement measures.

While a modicum of regulation has managed to discipline the domestic fishing fleet, foreign fishing vessels from China, Vietnam, and Taiwan have been carrying out large-scale illegal fishing within the country’s exclusive economic zone (EEZ) since 2012. Policing foreign vessels in territorial waters has been a significant geopolitical challenge for successive governments.

Growing plastic pollution is another menace altogether. Last year, the country attracted international attention when a young whale shark was found dead in Davao del Norte province and a biologist retrieved a cup, wrappers, and numerous other plastic items from its stomach. This incident has helped to highlight the acute nature of ocean pollution in Southeast Asia and the Philippines in particular. In 2018, the government permanently restricted access to Boracay, a favoured holiday destination and an important economic driver, because of the sheer amount of trash in the water. It has since reopened.

Ocean Conservancy, an NGO,  in its report ranked the Philippines as the world’s third-largest ocean polluter, as the country generates 2.7 million metric tons of plastic waste annually and disposes 20% of that directly into the ocean.  

Such a high concentration of plastic waste has caused disease outbreaks on the coral reef and irreversible harm to a number of marine species. Besides significant damage to marine habitats, the Philippine Sea recorded an overall decline of 29% of fish stocks. 

Only a strict enforcement mechanism and conservation methods based on a coordinated, national marine monitoring system can save the marine biodiversity and aquatic ecosystems of the Philippines. Other countries have demonstrated that it is possible for developing economies to couple sustained economic growth with a wise use of natural resources. 


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