Indo-Pacific

The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the seas connecting the two. 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. As a distinct marine realm, the region has an exceptionally high species richness, with the world's highest species richness being found at its heart in the Coral Triangle, and a remarkable gradient of decreasing species richness radiating outward in all directions. The region includes over 3,000 species of fish, compared with around 1,200 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. The term first appeared in academic use in oceanography and geopolitics. Scholarship has shown that the "Indo-Pacific" concept circulated in Weimar Germany, and spread to interwar Japan. German political oceanographers envisioned an "Indo-Pacific" comprising anticolonial India and republican China, as German allies, against "Euro-America". Since the late 2010s, the term "Indo-Pacific" has been increasingly used in geopolitical discourse. It is seen by some as a replacement for the "Asia-Pacific" regional concept which was pioneered by Australia and Japan in the 1970s and 1980s. Australia officially transitioned its strategic focus from the 'Asia-Pacific' to the 'Indo-Pacific' in 2013, becoming the first country to formally adopt the Indo-Pacific as its official strategic framework. As a geopolitical concept, the Indo-Pacific has a "symbiotic link" with the Quadrilateral Security Dialogue, or "Quad", an informal grouping between Australia, Japan, India, and...