Indo-Pacific

The Indo-Pacific is a large biogeographic area on Earth. More specifically, it is sometimes referred to as the Indo-West Pacific or Indo-Pacific Asia and includes the tropical waters of the Indian Ocean, the central and western parts of the Pacific Ocean, and the seas that link these two oceans. It does not cover the temperate and polar regions of either ocean, nor does it encompass the Tropical Eastern Pacific, which is found along the Pacific coast of the Americas and is considered a separate marine area. This term is particularly relevant in fields like marine biology and ichthyology because many marine environments are interconnected from Madagascar to Japan and Oceania. Numerous species inhabit this range but are absent from the Atlantic Ocean.

This region is known for its incredibly high biodiversity, with the Coral Triangle at its center hosting the greatest variety of species in the world. As you move outward from this area, there is a noticeable decrease in species diversity. The Indo-Pacific is home to over 3,000 fish species, far surpassing the approximately 1,200 species found in the next most diverse marine region, the Western Atlantic. Additionally, it boasts around 500 species of reef-building corals, compared to about 50 species in the Western Atlantic.

The term "Indo-Pacific" was first used in academic discussions related to oceanography and geopolitics. Research indicates that the concept gained traction in Weimar Germany and later spread to Japan during the interwar period. German political oceanographers envisioned an "Indo-Pacific" that included anticolonial India and republican China as allies against "Euro-America". Since the late 2010s, the term has become more prevalent in geopolitical conversations, closely linked to the Quadrilateral Security Dialogue (Quad), which is an informal alliance between Australia, Japan, India, and the United States. Some argue that this concept could reshape how people perceive global strategic dynamics. Political scientist Amitav Acharya notes that the "Indo-Pacific" was a notion developed by strategists, gaining prominence in international relations literature as a geopolitical counterpoint by the U.S. in its relations with China.