located in this region. Wildlife The wildlife of the Persian Gulf is diverse, and entirely unique because of the Persian Gulf's geographic distribution and its isolation from the international waters only breached by the narrow Strait of Hormuz. The Persian Gulf has hosted some of the most magnificent marine fauna and flora, some of which are near extirpation or at serious environmental risk. From corals, to dugongs, Persian Gulf is a diverse cradle for many species who depend on each other for survival. However, the Persian Gulf is not as biologically diverse as the Red Sea. Overall, the wild life of the Persian Gulf is endangered from both global factors, and regional, local negligence. Most pollution is from ships; land generated pollution counts as the second most common source of pollution. Aquatic mammals 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 Persian 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 Bryde's whales, these once common residents can still can be seen in deeper marginal seas such as Gulf of Aden, Israel coasts, and in the Strait of Hormuz. Other species such as the critically endangered Arabian humpback whale, (also historically common in Gulf of Aden and increasingly sighted in the Red Sea since 2006, including in the Gulf of Aqaba), omura's whale, minke whale, and orca also swim into the Persian Gulf, while many other large species such as blue whale, sei, and sperm whales were once migrants into the Gulf of Oman and off the coasts in deeper waters, and still migrate into the Red Sea, but mainly in deeper waters of outer seas. In 2017, waters of the Persian Gulf along Abu Dhabi were revealed to hold the world's largest population of Indo-Pacific humpbacked dolphins. One of the more unusual marine mammals living in the Persian Gulf is the dugong (Dugong dugon). Also called "sea cows", for their grazing habits and mild manner resembling livestock, dugongs have a life expectancy similar