Persian Gulf at its narrowest, in the Strait of Hormuz. The waters are overall very shallow, with a maximum depth of and an average depth of . Countries with a coastline on the Persian Gulf are (clockwise, from the north): Iran; Oman's Musandam exclave; the United Arab Emirates; Saudi Arabia Qatar, on a peninsula off the Saudi coast; Bahrain, on an island; Kuwait; and Iraq in the northwest. Various small islands also lie within the Persian Gulf, some of which are the subject of territorial disputes between the states of the region. The International Hydrographic Organization defines the Persian Gulf's southern limit
Persian Gulf the second most common source of pollution. Along the mediterranean regions of the Arabian Sea, including the Persian Gulf, the Red Sea, the Gulf of Kutch, the Gulf of Suez, the Gulf of Aqaba, the Gulf of Aden, and the Gulf of Oman, dolphins and finless porpoises are the most common marine mammals in the waters, while larger whales and orcas are rarer today. Historically, whales had been abundant in the gulf before commercial hunts wiped them out. Whales were reduced even further by illegal mass hunts by the Soviet Union and Japan in the 1960s and 1970s. Along with