The Indo-Pacific, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, is a biogeographic region of Earth's seas, comprising the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the seas connecting the two in the general area of Indonesia. It does not include the temperate and polar regions of the Indian and Pacific oceans, nor the Tropical Eastern Pacific, along the Pacific coast of the Americas, which is also a distinct marine realm.

The term is especially useful in marine biology, ichthyology, and similar fields, since many marine habitats are continuously connected from Madagascar to Japan and Oceania, and a number of species occur over that range, but are not found in the Atlantic Ocean.

The region has an exceptionally high species richness, including 3000 species of fish, compared with around 1200 in the next richest marine region, the Western Atlantic, and around 500 species of reef building corals, compared with about 50 species in the Western Atlantic.[1]

Indo-Pacific biogeographic region map-en
Area covered by the Indo-Pacific biogeographic region


The WWF and Nature Conservancy divide the Indo-Pacific into three realms (or subrealms), and each of these into a number of marine provinces.

Central Indo-Pacific

The Central Indo-Pacific includes the numerous seas and straits connecting the Indian and Pacific oceans, including the seas surrounding the Indonesian archipelago (with the exception of Sumatra's northwest coast, which is part of the Western Indo-Pacific), the South China Sea, the Philippine Sea, the north coast of Australia, and the seas surrounding New Guinea, western and central Micronesia, New Caledonia, the Solomon Islands, Vanuatu, Fiji, and Tonga. The Central Indo-Pacific, due in part to its central location at the meeting of two oceans, has the greatest diversity of corals and mangroves.

Eastern Indo-Pacific

The Eastern Indo-Pacific surrounds the mostly volcanic islands of the central Pacific Ocean, extending from the Marshall Islands through central and southeastern Polynesia to Easter Island and Hawaii.

Western Indo-Pacific

The Western Indo-Pacific covers the western and central portion of the Indian Ocean, including Africa's east coast, the Red Sea, Gulf of Aden, Persian Gulf, Arabian Sea, Bay of Bengal, and Andaman Sea, as well as the coastal waters surrounding Madagascar, the Seychelles, Comoros, Mascarene Islands, Maldives, and Chagos Archipelago.

Economic region

With the rising involvement of the US in the new growth areas of Asia, the idea of the Indo-Pacific Economic Corridor was conceptualized during the US-India Strategic Dialogue of 2013, where Secretary of State John Kerry referred to the potential of the Indo-Pacific Economic Corridor, in transforming the prospects for development and investments as well as for trade and transit between the economies of South and Southeast Asia Indo-Pacific economic corridor. [2]

K. Y. Home in his scholarly study has mapped out the potential for various emerging trans-regional corridors in Asia along with the challenges of linking IPEC into the larger web of regional economic integration initiatives taking shape in the region in 2017.[3]

Strategic/geopolitical context

Since 2011, the term ‘Indo-Pacific’ is being used increasingly in the global strategic/ geopolitical discourse. In its way, the term "Indo-Pacific" can be thought of in the same way as using terms like "Post-Rock" or "World Fusion." The concept is not new to the geopolitical discourse. The German geopolitician Karl Haushofer first used it in the 1920s in his academic work called "Indopazifischen Raum". [4] Since then, intermittently, many analysts sought to describe the 'geo-economic' connect between the Indian and Pacific Oceans. However, in the contemporary context, beginning the 2000s, analysts began to observe the 'security' linkage between the two Oceans. In this context, the term was first used in an article authored by Gurpreet Khurana, which was carried in the January 2007 issue of the Strategic Analysis journal (Routledge/ IDSA) titled "Security of Sea Lines: Prospects for India-Japan Cooperation". In the article, the term ‘Indo-Pacific’ refers to the maritime space stretching from the littorals of East Africa and West Asia, across the Indian Ocean and western Pacific Ocean, to the littorals of East Asia.[5] The spirit of the term was picked up by Japan's Prime Minister Shinzō Abe, as reflected in his speech to the Indian Parliament in August 2007 that talked about the "Confluence of the Indian and Pacific Oceans" as "the dynamic coupling as seas of freedom and of prosperity" in the "broader Asia".[6][7] From 2010 onwards, the term Indo-Pacific acquired salience within the Indian government and has since been used often by India's apex political leadership.[8] From about 2011 onwards, the term has been used frequently by strategic analysts and high-level government/military leadership in Australia, Japan and the US to denote said region. However, a formal/ official documented articulation of the term first appeared in Australia’s Defence White Paper, 2013.[9]

It has been argued that the concept of the Indo-Pacific may lead to a change in popular "mental maps" of how the world is understood in strategic terms.[10] In 2013, US officials have begun using the term "Indo-Asia Pacific".[11] This enabled America to maintain its geographic inclusiveness in the new coinage of 'Indo-Pacific'.

The term's profile was raised when it found mention in the joint statement issued by the Indian Prime Minister Narendra Modi and United States President Donald Trump after the former's state visit to the White House on 26 June 2017. "As responsible stewards in the Indo-Pacific region, President Trump and Prime Minister Modi agreed that a close partnership between the United States and India is central to peace and stability in the region. In marking 70 years of diplomatic relations between India and the United States, the leaders resolved to expand and deepen the strategic partnership between the countries and advance common objectives. Above all, these objectives include combatting terrorist threats, promoting stability across the Indo-Pacific region, increasing free and fair trade, and strengthening energy linkages". [12]

See also

Further reading

  • Spalding, Mark D., Helen E. Fox, Gerald R. Allen, Nick Davidson et al. "Marine Ecoregions of the World: A Bioregionalization of Coastal and Shelf Areas". Bioscience Vol. 57 No. 7, July/August 2007, pp. 573–583.


  1. ^ Helfman G., Collette B., & Facey D.: The Diversity of Fishes, Blackwell Publishing, pp 274-276, 1997, ISBN 0-86542-256-7
  2. ^ Sundararaman, Shankari (February 10, 2017). "Indo-Pacific economic corridor: A vision in progress". Observer Research Foundation.
  3. ^ Yhome, K.; Chaturvedy, Rajeev Ranjan (2017). "Emerging Trans-Regional Corridors: South and Southeast Asia" (PDF). Observer Research Foundation. ISBN 978-81-86818-26-8.
  4. ^ Karl Ernst Haushofer, Lewis A Tambs, Ernt J Brehm. An English translation and analysis of Major General Karl Ernst Haushofer's Geopolitics of the Pacific Ocean: Studies on the relationship between Geography and History. (Lewiston, N.Y, Edwin Mellen Press: 2002)
  5. ^ Khurana, Gurpreet S. , (2007) 'Security of Sea Lines: Prospects for India-Japan Cooperation', Strategic Analysis, Volume 31, No. 1, pp. 139–153
  6. ^ "Confluence of the Two Seas". Ministry of Foreign Affairs Japan. August 22, 2007. Speech by H.E. Mr. Shinzo Abe, Prime Minister of Japan at the Parliament of the Republic of India
  7. ^ "Maritime Policy Archives - ORF". ORF.
  8. ^ Scott, David (2012) "India and the Allure of the 'Indo-Pacific'", International Studies, 49(3&4), pp. 1–24, Sage Publications, London
  9. ^ Defending Australia and its National Interests, Defence White Paper 2013, Department of Defence, Australian Government, May 13
  10. ^ Brewster, David. "Dividing Lines: Evolving Mental Maps of the Bay of Bengal".
  11. ^ Miles, Donna (8 February 2013). "Locklear Calls for Indo-Asia-Pacific Cooperation". U.S. Department of Defense.
  12. ^ "Joint Statement - United States and India: Prosperity Through Partnership". Ministry of External Affairs. 27 June 2017.
Central Indo-Pacific

The Central Indo-Pacific is a biogeographic region of the Earth's seas, comprising the tropical waters of the western Pacific Ocean, the eastern Indian Ocean, and the connecting seas.

The Central Indo-Pacific is part of the larger Indo-Pacific, which includes the tropical Indian Ocean, the western and central tropical Pacific Ocean, and the seas connecting the two in the general area of Indonesia. The Central Indo-Pacific may be classified as a marine realm, one of the great biogeographic divisions of the world's ocean basins, or as a subrealm of the Indo-Pacific.

The Central Indo-Pacific realm covers eastern shores of the tropical Indian Ocean, including most of the Indian Ocean coast of the Indonesian archipelago, the northern Australian coast, and the Cocos and Christmas islands. It extends through the tropical seas connecting the Pacific and Indian Oceans, including the Java Sea in central Indonesia, the South China Sea between the Asian land mass and the Philippine and Malay archipelagos, and the Arafura Sea separating Australia and New Guinea. It includes the seas surrounding island groups of the western Pacific, including the Ryukyu Islands, Caroline Islands, Marianas Islands, New Guinea and the Bismarck Archipelago, Solomon Islands, Vanuatu, New Caledonia, Fiji, Tonga, and Lord Howe Island.

It is bounded on the west by the Western Indo-Pacific, with the transition at the Strait of Malacca and in southern Sumatra. The Central Indo-Pacific includes the seas surrounding the northern half of Australia, while the Temperate Australasia marine realm includes the seas surrounding the southern half of Australia. The boundaries between those two marine realms lie in Western Australia and southern Queensland. The Eastern Indo-Pacific lies to the east, extending across most of tropical Polynesia. To the north, the Taiwan Strait forms the boundary with the Temperate Northern Pacific, which also includes the larger Japanese islands.

The Central Indo-Pacific has the greatest diversity of tropical corals in the world, and includes the largest and second-largest coral formations in the world, Australia's Great Barrier Reef and the New Caledonia Barrier Reef.


A corallivore is an animal that feeds on coral. Corallivores are an important group of reef organism because they can influence coral abundance, distribution, and community structure. Corallivores feed on coral using a variety of unique adaptations and strategies. Animals known to be corallivores include certain mollusks, annelids, fish, crustaceans, flatworms and echinoderms. The first recorded evidence of corallivory was presented by Charles Darwin in 1842 during his voyage on HMS Beagle in which he found coral in the stomach of two Scarus parrotfish.

Finless porpoise

The Indo-Pacific finless porpoise (Neophocaena phocaenoides), or finless porpoise, is one of seven porpoise species. Most of the population has been found around the Korean peninsula in the Yellow and East China Seas, although a freshwater population is found around Jiuduansha near Shanghai at the mouth of China's Yangtze River. Genetic studies indicate that the finless porpoise is the most basal living member of the porpoise family.There is a degree of taxonomic uncertainty surrounding the species, with the N. p. phocaenoides subspecies perhaps representing a different species from N. p. sunameri and N. p. asiaeorientalis, currently reclassified as the narrow-ridged finless porpoise.

Global 200

The Global 200 is the list of ecoregions identified by

WWF, the global conservation organization, as priorities for conservation. According to WWF, an ecoregion is defined as a "relatively large unit of land or water containing a characteristic set of natural communities that share a large majority of their species dynamics, and environmental conditions". So, for example, based on their levels of endemism, Madagascar gets multiple listings, ancient Lake Baikal gets one, and the North American Great Lakes get none.

The WWF assigns a conservation status to each ecoregion in the Global 200: critical or endangered; vulnerable; and relatively stable or intact. Over half of the ecoregions in the Global 200 are rated endangered.

Global Rapid Rugby

Global Rapid Rugby is an international rugby union competition that launched a showcase series for six professional teams in 2019, played in locations across the Asia-Pacific region. Rapid Rugby matches are slightly shorter than the traditional 80 minutes and have other variations from standard rugby laws that are intended to increase the speed of the game.The competition was conceived and is supported by the Australian billionaire Andrew Forrest. It was devised after the Western Force rugby team based in Perth, Western Australia was dropped from the Australian Super Rugby Conference.

Humpback dolphin

Humpback dolphins are members of the genus Sousa. These dolphins are characterized by the conspicuous humps and elongated dorsal fins found on the backs of adults of the species. They are found close to shore along the coast of West Africa (Atlantic species/variety) and right along the coast of the Indian Ocean from South Africa to Australia (Indo-Pacific species/varieties). Several institutions have made a proposal to divide the Indo-Pacific species into two distinct species: the Indo-Pacific humpback dolphin and the Australian humpback dolphin.

Indian Ocean humpback dolphin

The Indian Ocean humpback dolphin (Sousa plumbea) is a member of the Delphinidae family occupying coastal areas ranging from Southern Africa to Western Indochina. The Indo-Pacific humpback dolphin (Sousa chinensis) was formerly included within the same species, but a 2014 study revealed them to be a separate species.The most limiting factor to habitat-usage is water depth, with most specimens remaining in waters shallower than 20 meters. As a result, the Indian Ocean humpbacked dolphin's offshore range is largely dependent on the coastlines' specific physiographical characteristics. The species has been reported to inhabit nearly every type of coastal habitat, although preference and prominence of any given habitat type is highly dependent on the geographical location. Indian Ocean humpbacked dolphins experience extremely high rates of calf and juvenile mortality due to anthropogenic disturbances such as environmental pollution, habitat deterioration and noise pollution.

Indian Ocean humpbacked dolphins are social delphinids that live in groups averaging twelve individuals, although group size can be highly variable. The majority of their diet is composed of sciaenid fishes, cephalopods, and crustaceans.

The species is currently categorized as Endangered.

Indo-Pacific bottlenose dolphin

The Indo-Pacific bottlenose dolphin (Tursiops aduncus) is a species of bottlenose dolphin. This dolphin grows to 2.6 m (8.5 ft) long, and weighs up to 230 kg (510 lb). It lives in the waters around India, northern Australia, South China, the Red Sea, and the eastern coast of Africa. Its back is dark grey and its belly is lighter grey or nearly white with grey spots.Until 1998, all bottlenose dolphins were considered members of the single species T. truncatus. In that year, the Indo-Pacific bottlenose dolphin was recognized as a separate species. The Indo-Pacific bottlenose dolphin is generally smaller than the common bottlenose dolphin, has a proportionately longer rostrum, and has spots on its belly and lower sides. It also has more teeth than the common bottlenose dolphin — 23 to 29 teeth on each side of each jaw compared to 21 to 24 for the common bottlenose dolphin. Some evidence shows the Indo-Pacific bottlenose dolphin may actually be more closely related to certain dolphin species in the genera Stenella and Delphinus, especially the Atlantic spotted dolphin (S. frontalis), than it is to the common bottlenose dolphin.Much of the old scientific data in the field combine data about the Indo-Pacific bottlenose dolphin and the common bottlenose dolphin into a single group, making it effectively useless in determining the structural differences between the two species. The IUCN lists the Indo-Pacific bottlenose dolphin as "data deficient" in their Red List of endangered species because of this issue.

Indo-Pacific humpback dolphin

The Indo-Pacific humpback dolphin (Sousa chinensis; Chinese: 中華白海豚; pinyin: Zhōnghuá bái hǎitún). is a species of humpback dolphin inhabiting waters off the coast of Southeast Asia and Australia. Some biologists regard the Indo-Pacific dolphin as a subspecies of the Indian Ocean humpback dolphin which ranges from east Africa to India. However, DNA testing studies have shown that the two are distinct species. Indo-Pacific humpback dolphins from the Pearl River Delta in Hong Kong are often pink in color and often referred to as Chinese white dolphins.

Indo-Pacific king mackerel

Indo-Pacific king mackerel or popularly (spotted) seer fish (Scomberomorus guttatus) is a sea fish among the mackerel variety of fishes. It is found in around the Indian Ocean and adjoining seas.It is a popular game fish, growing up to 45 kg (100 lb), and is a strong fighter that has on occasion been seen to leap out of the water when hooked.

It is popular among the countries of the Indian subcontinent including Pakistan, India, Sri Lanka and Bangladesh. In India, it is also known by anjal, surmai and iswan. In addition to being cooked and eaten when fresh, it is also used to make fish pickle, usually eaten as a condiment with rice.

Indo-Pacific slender worm-eel

The Indo-Pacific slender worm-eel (Scolecenchelys gymnota, also known as the Slender worm eel) is an eel in the family Ophichthidae (worm/snake eels). It was described by Pieter Bleeker in 1857. It is a marine, tropical eel which is known from the Indo-Pacific, including the Red Sea, East Africa, the Line Islands, the Society Islands, Johnston Island, Japan, Rapa Iti, Micronesia, and the southern Great Barrier Reef. It forms burrows in inshore sediments of loose gravel and sand. Males can reach a maximum total length of 38 centimetres (15 in).


Paracanthurus hepatus is a species of Indo-Pacific surgeonfish. A popular fish in marine aquaria, it is the only member of the genus Paracanthurus. A number of common names are attributed to the species, including regal tang, palette surgeonfish, blue tang (leading to confusion with the Atlantic species Acanthurus coeruleus), royal blue tang, hippo tang, blue hippo tang, flagtail surgeonfish, Pacific regal blue tang, and blue surgeonfish.

Portuguese man o' war

The Portuguese man o' war (Physalia physalis), also known as the man-of-war, is a marine hydrozoan found in the Atlantic, Indian and Pacific Oceans. It is one of two species in the genus Physalia, along with the Pacific man o' war (or Australian blue bottle), Physalia utriculus. Physalia is the only genus in the family Physaliidae. Its long tentacles deliver a painful sting, which is venomous and powerful enough to kill fish or, rarely, humans. Despite its appearance, the Portuguese man o' war is not a true jellyfish but a siphonophore, which is not actually a single multicellular organism (true jellyfish are single organisms), but a colonial organism made up of specialized individual animals (of the same species) called zooids or polyps. These polyps are attached to one another and physiologically integrated, to the extent that they cannot survive independently, creating a symbiotic relationship, requiring each polyp to work together and function like an individual animal.

Sea apple

Sea apple is a common name for the colorful and somewhat round sea cucumbers of the genera Pseudocolochirus, found in Indo-Pacific waters. Sea apples are filter feeders with tentacles, ovate bodies, and tube-like feet. They can release their internal organs or a toxin into the water when stressed.

Temperate Northern Pacific

The Temperate Northern Pacific is a biogeographic region of the Earth's seas, comprising the temperate waters of the northern Pacific Ocean.

The Temperate Northern Pacific connects, via the Bering Sea, to the Arctic marine realm, which includes the polar waters of the Arctic Sea. To the south, it transitions to the tropical marine realms of the Pacific, including the Tropical Eastern Pacific along the Pacific coast of the Americas, the Eastern Indo-Pacific in the central Pacific Ocean, and the Central Indo-Pacific of the western Pacific basin. The Taiwan Strait forms the boundary between the Temperate Northern Pacific and the Central Indo-Pacific.

Characteristic fauna include the Pacific salmon and trout (Oncorhynchus spp.), gray whale (Eschrichtius robustus), and North Pacific right whale (Eubalaena japonica).

Tropical bottlenose whale

The tropical bottlenose whale (Indopacetus pacificus), also known as the Indo-Pacific beaked whale and Longman's beaked whale, was considered to be the world's rarest cetacean until recently, but the spade-toothed whale now holds that position. As of 2010, the species is now known from nearly a dozen strandings and over 65 sightings.

United States Indo-Pacific Command

United States Indo-Pacific Command (USINDOPACOM) is a unified combatant command of the United States Armed Forces responsible for the Indo-Pacific region. It is the oldest and largest of the unified combatant commands. Its commander, the senior U.S. military officer in the Pacific, is responsible for military operations in an area which encompasses more than 100 million square miles (260,000,000 km2), or roughly 52 percent of the Earth’s surface, stretching from the waters off the West Coast of the United States to the west coast of India, and from the Arctic to the Antarctic. The U.S. command is also responsible of protecting against an invasion of the United States through the state of Hawaii.

The commander reports to the President of the United States through the Secretary of Defense and is supported by service component and subordinate unified commands, including U.S. Army Pacific, Marine Forces Pacific, U.S. Pacific Fleet, Pacific Air Forces, U.S. Forces Japan, U.S. Forces Korea, Special Operations Command Korea, and Special Operations Command Pacific. USINDOPACOM also has two direct reporting units (DRUs)—U.S. Pacific Command Joint Intelligence Operations Center (JIOC) and the Center for Excellence in Disaster Management and Humanitarian Assistance (CFE-DMHA), as well as a Standing Joint Task Force, Joint Interagency Task Force West (JIATF-W). The USINDOPACOM headquarters building, the Nimitz-MacArthur Pacific Command Center, is located on Camp H. M. Smith, Hawaii.

Formerly known as United States Pacific Command (USPACOM) since its inception, the command was renamed to U.S. Indo-Pacific Command on 30 May 2018, in recognition of the greater emphasis on the Indian subcontinent.

United States Marine Corps Forces, Pacific

Marine Forces Pacific (MARFORPAC) is the United States Marine Corps service component command of United States Indo-Pacific Command. It is the largest field command in the Marine Corps and is headquartered at Camp H. M. Smith in Hawaii.

It is composed of the I Marine Expeditionary Force (I MEF) and the III Marine Expeditionary Force (III MEF). Each MEF comprises a command element (CE), a ground combat element (GCE) (1st and 3rd Marine Divisions), an aviation combat element (ACE) (1st and 3rd Marine Aircraft Wings), and a logistics combat element (LCE) (1st and 3rd Marine Logistics Groups).

Western Indo-Pacific

The Western Indo-Pacific is a biogeographic region of the Earth's seas, comprising the tropical waters of the eastern and central Indian Ocean. It is part of the larger Indo-Pacific, which includes the tropical Indian Ocean, the western and central Pacific Ocean, and the seas connecting the two in the general area of Indonesia. The Western Indo-Pacific may be classified as a marine realm, one of the great biogeographic divisions of the world's ocean basins, or as a subrealm of the Indo-Pacific.

The Western Indo-Pacific realm covers the western and central portion of the Indian Ocean, including Africa's east coast, the Red Sea, Gulf of Aden, Persian Gulf, Arabian Sea, Bay of Bengal, and Andaman Sea, as well as the coastal waters surrounding Madagascar, the Seychelles, Comoros, Mascarene Islands, Maldives, and Chagos Archipelago.

The transition between the Western Indo-Pacific and Central Indo-Pacific occurs at the Strait of Malacca and in southern Sumatra.

The Western Indo-Pacific does not include the temperate and polar waters of the Indian Ocean, which are part of separate marine realms. The boundary between the Western Indo-Pacific and Temperate Southern Africa marine realms lies in southern Mozambique, where the southernmost mangroves and tropical corals are found.

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