Fishing fleets from Russia , Japan , South Korea , and Taiwan also exploit the Indian Ocean, mainly for shrimp and tuna. Large reserves of hydrocarbons are being tapped in the offshore areas of Saudi Arabia , Iran , India , and western Australia . Beach sands rich in heavy minerals and offshore placer deposits are actively exploited by bordering countries, particularly India , South Africa , Indonesia , Sri Lanka , and Thailand . It is separated from the Atlantic Ocean by the 20 deg east meridian south of Africa, and from the Pacific by the 147 deg east meridian. The northernmost extent of the Indian Ocean is approximately 30 deg north latitude in the Persian Gulf.
Small islands dot the continental rims.
Indonesia borders it. The ocean's importance as a transit route between Asia and Africa has made it a scene of conflict. Because of its size, however, no one nation had successfully dominated until the early 1800s when Britain controlled much of the surrounding land. Its strategic importance far outweighs the economic value of its minerals or marine life. The African, Indian, and Antarctic crustal plates converge in the Indian Ocean.