Persian Gulf flooding of the basin started 15,000 years ago due to rising sea levels of the Holocene glacial retreat. This inland sea of some is connected to the Gulf of Oman in the east by the Strait of Hormuz; and its western end is marked by the major river delta of the Shatt al-Arab, which carries the waters of the Euphrates and the Tigris. In Iran this is called "Arvand Rood", where "Rood" means "river". Its length is , with Iran covering most of the northern coast and Saudi Arabia most of the southern coast. The Persian Gulf is about wide
Persian Gulf fishing grounds, extensive reefs (mostly rocky, but also coral), and abundant pearl oysters, but its ecology has been damaged by industrialization and oil spills. The body of water is historically and internationally known as the "Persian Gulf". Some Arab governments refer to it as the "Arabian Gulf" () or "The Gulf", but neither term is recognized internationally. The name "Gulf of Iran (Persian Gulf)" is used by the International Hydrographic Organization. The Persian Gulf resides in the Persian Gulf Basin, which is of Cenozoic origin and related to the subduction of the Arabian Plate under the Zagros Mountains. The current