Coral Triangle facts

More coral reef species than anywhere else on Earth.

Six of the world's 7 marine turtle species.

A 6-million km2 ecosystem that fuels economies and supports the livelihoods of more than 100 million people.

This is the Coral Triangle.

About the Coral Triangle

The Coral Triangle is a marine region that spans those parts of Indonesia, Malaysia, Papua New Guinea, the Philippines, the Solomon Islands and Timor-Leste with at least 500 species of reef-building corals.1 The Coral Triangle encompasses portions of 2 biogeographic regions: the Indonesian-Philippines Region, and the Far Southwestern Pacific Region.2

Coral Triangle biodiversity

  • 76% (605) of the world’s coral species (798) are found in the Coral Triangle, the highest coral diversity in the world.
  • The epicenter of that coral diversity is found in the Bird’s Head Peninsula of Indonesian Papua, which hosts 574 species (95% of the Coral Triangle, and 72% of the world’s total). Within the Bird’s Head Peninsula, the Raja Ampat archipelago is the world’s coral diversity bull’s eye with 553 species.
  • The Coral Triangle has 15 regionally endemic coral species (species found nowhere else in the world), and shares 41 regional endemic species with Asia.

Coral reef fishes3

  • The Coral Triangle has more coral reef fish diversity than anywhere else in the world: 37% (2,228) of the world’s coral reef fish species (6,000), and 56% of the coral reef fishes in the Indo-Pacific region (4,050).
  • 8% (235 species) of the coral reef fishes in the Coral Triangle are endemic or locally restricted species. Within the Coral Triangle, four areas have particularly high levels of endemism (Lesser Sunda Islands, Papua New Guinea – Solomon Islands, Bird’s Head Peninsula, and the Central Philippines).
Marine turtles
  • 6 of the world's 7 marine turtle species, including the leatherback marine turtle, found in places such as the Northern Bird's Head Peninsula / Waigeo region, Papua (Indonesia), as well as Lea region (Papua New Guinea), New Georgia (Solomon Islands).

Cetaceans (whales, dolphins etc.)4
  • The Coral Triangle is frequented by the blue whale, the largest animal to ever live on Earth.
  • Other Coral Triangle whales include the sperm whale (found throughout Coral Triangle waters and the Savu Sea, especially Solor-Alor region).
  • Dolphins, porpoises, and the endangered dugong.
Fiji is famous throughout the world for spectacularly rich and vibrant soft coral reefs. Fed by ... 
Fiji is famous throughout the world for spectacularly rich and vibrant soft coral reefs. Fed by nutrient rich currents, these soft coral gardens are havens and food sources for thousands of species of fish and invertebrates. Soft, corals, hard corals and anthias fish, Fiji.
	© WWF / Jürgen FREUND
Common green turtle (Chelonia mydas) swimming on ground with remora fish on its back. Indo Pacific Ocean
© WWF / Jürgen FREUND
	© Jürgen Freund/WWF
Whale shark swimming with divers
© Jürgen Freund/WWF

Why the Coral Triangle (and not a circle)?

The Coral Triangle is defined by marine zones containing at least 500 species of reef-building coral—the darkest area that is roughly triangular in shape shown in the map above.

Certain neighbouring countries, including Australia and Fiji, contain rich coral biodiversity as well, but with somewhat lower numbers.

The main criteria used by scientists and conservationists to delineate the Coral Triangle were:

  • High species biodiversity (more than 500 coral species, high biodiversity of reef fishes, foraminifera, fungid corals, and stomatopods) and habitat diversity
  • Oceanography (currents)5
The Coral Triangle region is highlighted below in blue.

View WWF Critical Regions of the World in a larger map
	© Coral Geographic (Veron et al unpublished data).
Coral Triangle Boundary
© Coral Geographic (Veron et al unpublished data).

Below and above the sea, substantial economic value

The Coral Triangle supports livelihoods and provides income and food security, particularly for coastal communities. Resources from the area directly sustain more than 120 million people living in the area.

The Coral Triangle’s economic value is nothing short of phenomenal:
  • Tuna spawning and nursery grounds support a multi-billion dollar tuna industry and supply millions of consumers worldwide
  • Marine resources contribute to a growing nature-based tourism industry, valued at over US$12 billion annually
Local fishermen with tuna catch Sulu Sea, Philippines 
	© Jürgen FREUND / WWF
Local fishermen with tuna catch Sulu Sea, Philippines
© Jürgen FREUND / WWF

Economic growth brings new pressures on the Coral Triangle

The Coral Triangle is part of an area that has emerged as one of the planet’s economic hubs. Fast population and economic growth have fuelled unsustainable coastal development and boosted demand for expensive marine resources such as tuna, shark fin, turtle products and live reef fish.

Now, the challenge is to ensure that the growing needs of the region do not make the wonders of the Coral Triangle something of the past…


1 Veron et al. Unpublished data
2 Veron, J.E.N. 1995. Corals in space and time: biogeography and evolution of the Scleractinia. UNSW Press, Sydney, Australia: xiii + 321 pp.
3 Allen, G. R. 2007 Conservation hotspots of biodiversity and endemism for Indo-Pacific coral reef fishes. Aquatic Conserv: Mar. Freshw. Ecosyst. DOI: 10.1002/aqc.880.
4 Benjamin Kahn, pers. comm.
5 The Nature Conservancy. 2004. Delineating the Coral Triangle, its ecoregions and functional seascapes. Report on an expert workshop, held at the Southeast Asia Center for Marine Protected Areas, Bali, Indonesia, (April 30 - May 2, 2003), Version 1.1 (June 2004).

The Coral Triangle Numbers

    • 6 million km2 area
    • 76% of the world’s coral species
    • 6 of the world’s 7 marine turtle species
    • Sustains 120 million people
    • US$12 billion nature-based tourism industry (yearly)

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