Indonesia Diving Information  Wonderful Indonesia Indonesia, consisting of about 18,000 islands, is a mysterio […]

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The Philippines

The Philippines Diving Information  The Philippines, which consists of 7,107 islands, has long been visited by […]

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Timor L'este

Timor L'este Diving Information The Coral Triangle Last Unexplored territory, East Timor. The strait between T […]

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MELTING POT : PAPUA NEW GUINEA Diving site information are up for most areas!Papua New Guinea is surrounded by […]

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The Solomon Islands

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The Coral Triangle

"The Amazon of the Seas"

The Amazon of the Seas

More than 500 corals and 2,500 coral reef fishes are said to live in the triangular waters surrounding the Philippines, Malaysia, Indonesia, East Timor, Papua New Guinea and Solomon Islands. The coral triangle is a treasure trove of various marine organisms and is also called an ocean amazon because of the plentiful phytoplankton that bathes in the intense sunlight directly under the equator and generates oxygen. It is currently an area in need of protection for the global environment alongside with the Amazon forest, which is said to generate 1/6 of the oxygen on earth because of the large amount of oxygen generated. At the same time, valuable marine resource protection projects are presently in progress under the management of the Coral Triangle Initiative and WWF etc. The area surrounded by the red "Boundary" is the currently protected area.

Protect ”Coral Triangle”! : The global center of marine biodiversity!

Solomon Islands:490 Coral spiecies
Papua New Guinea Kimbe Bay : 350 spieces of hard coral & 860 spieces of reef fish
Raja Ampat : 540 coral spieces & 1074 spieces of reef fish
Komodo : 350 coral spieces & 1000 spieces of reef fish

Boundary of Coral Triangle : Massive Marine Protected Area

The Coral Triangle

"Fish Diversity"

The secret of diversity! The migration and diffusion of coral reef.

Treasure trove of marine life

The richest marine ecosystem

The Coral Triangle is said to be an area that holds the world's richest marine ecosystem. Over the years, the complex ocean current of the coral triangle and the ocean bottom topography have bred a plethora of creatures. In addition, divers worldwide are pouring into these areas where they can meet the most diverse of organisms.

The tropical coral reef fish evolved and diversified around islands surrounded by coral reefs and also around the coral triangle with many atolls, it is said that it moved to the Pacific islands and settled there. Two hundred million years ago this place was called the Tethys Sea and it was a few shallow shores just directly under the equator. Also, 20,000 years ago during the ice age, the sea level is about 100 meters lower than the current one, in addition the place that lies on the big straits that bisects the land masses of Australia, Papua New Guinea and the land masses of Southeast Asia is called Wallacea.
 It is the Wallace Line that divides the biota of the Australia ward called Sundaland and the Sahul Shelf in the oriental district into two, dividing the biota between Borneo and Celebes and between Bali and Lombok. In terms of mammal’s distribution, elephants inhabit the island of Borneo. Although there is no huge carnivorous mammal on the Australian land mass of the Sahul Shelf, it is famous for many marsupials and terrestrial birds that resides there. On the other hand、the east side of the Wallace Line is also a Weber line that is divided into two based on differences in the distribution of shellfish and mammals. is not about which of the two lines are correct, it is that there are different kinds of creatures in the east and west, and it is a sign showing the biodiversity in the surrounding area. Currently not only on land, but also in the waters, the coral triangle are scattered almost all over the earth, deep trenches and islands of tropical rain forests just under the nutrient-rich equator. It is also said that the flow of different nutrients from Sundaland and the Sahul Shelf also contributes to the diversity of the reefs. Geographically, the ocean current flows are rather complicated among many islands that centered on volcanic islands. in addition, it also forms a complex ocean bottom topography. The types and population of coral and coral reef fish are precious treasures that the earth has made. Regretfully, It is said that this sea ecosystem will disappear within 100 years unless thorough environmental protection is taken. 

The Coral Triangle

"Throughflow "

Diversity Secret Consideration from the amount of Throuhgflow of Water

Throughflow that winds up nutrients

Another secret of the Coral Triangle's biodiversity is the world's largest flow of water. As running water from the Pacific Ocean passes through the Indonesian seawater basin, it pumps up deep sea nutrients. Not only the movement of ocean currents on the surface between complex islands, but also the rapid passage of huge amounts of water through narrow and shallow straits after passing through the deep-sea basin is a major feature of this area. An important feature of Indonesia's once-through is that the western Pacific current near the equator carries large amounts of warm, fresh water to the Indian Ocean. When the Indonesian current (through the Lombok Strait, Ombai Strait, and Timor route) enters the Indian Ocean, it becomes the South Equatorial Current of India, and finally leaves the Indian Ocean to South Africa and then to the Atlantic Ocean. Indonesia's once-through carries the heat of the Pacific Ocean to the southwestern Indian Ocean, about 10,000 km (6,200 miles) from the Lombok Strait.


The Indonesian Throughflow transports 15 Sv(15million cubic meter seawater every second)
Abundant underwater nutrient sources due to huge amount of once-through water

Numbers shown above are Sv. in Indonesia
■In oceanography, sverdrup (symbol: Sv) is used to measure the volumetric velocity of ocean currents. 1Sv is 1 million cubic meters per second (260,000,000 US gal)

■The strait along the Wallace Line between Bali and Lombok was a strait even before the Ice Age, so a large amount of water (12.7sv) passes through it. It also boosts the nutrients of the deep-sea basin of the Banda Sea, and a large amount of water (7.5 sv) flows to the south of Timor Island. This is said to be the true source of vitality for the Coral Triangle.

The Coral Triangle

The coastline of Wallacea,15,000 yesrs ago in the last ice age

The coastline of Wallacea,15,000 years ago in the last ice age

Sundaland, Wallacea ocean, and the Sahul Shelf

About 15,000 years ago, the lake of the ice ages was about 95m lower in sea level than the present, and so the diversified creatures moved onto land. This is also why elephants live on the present day Borneo Island.The Bali tiger also inhabited Bali until about the 1940s. Interestingly, Marsupials such as kangaroos inhabiting the Sahul Shelf were able to expand their habitat without encountering the tiger.

Warresia waters

The ocean waters between Sundaland and Sahul Shelf, which is called Wallacea (named by Wallace) is the current coral triangle. It is said that the current reef fish in this area has evolved and diversified around the islands. Coral reefs such as the Great Barrier Reef and the New Guinea Barrier Reef in the vicinity were said to have developed over a long period of time, due to lack of change in the coastline from Wallacea to the west coast of Australia.

The end of the ice age and Wallacea

When the Ice age finally ended 10,000 years ago, Murray, Sumatra island and Borneo island are separated by the rising sea level while Sundaland disappears. The coral of this coastal coastline is shallow the day it became part of the ocean, since the ocean here are shallow, the corals are not relatively diversified compared to Wallacea and the northern and eastern part of New Guinea.

Characteristics of terrestrial organisms

This series of coastline fluctuations is said to contribute to the diversification of coral triangle living organisms. Also, regarding terrestrial organisms, Indonesia has the world's largest lizard comodo dragon with the tail longer than the comodo dragon in terms of body length, and grows to about 5m in length, and many other endemic species such as the lizard harp butterfly keeps a variety of ecosystems. The surrounding area of Wallacea, now called the Coral Triangle is said to be the most abundant and with more biodiversity hotspots than anywhere else in the world.

Pangea 150,000,000 years ago : Quoted by " Coral Kingdams" by Carl Roessler

Two Land Masses -15,000 years ago in Ice Age Sea level is more than 130m lower than today
Wallace sea lay between two land masses


「The map of major dive sites」in Coral Triangle -Update Information-