|Gulf of Aden|
|Location||East Africa and Western Asia|
|Surface area||410,000 km2 (160,000 sq mi)|
|Average depth||500 m (1,600 ft)|
|Max. depth||2,700 m (8,900 ft)|
|Max. temperature||28 °C (82 °F)|
|Min. temperature||15 °C (59 °F)|
|Settlements||Aden, Djibouti, Berbera|
The Gulf of Aden (Arabic: ? , Somali: Gacanka Cadmeed ? ) also known as the Gulf of Berbera is a deepwater gulf between Yemen to the north, the Arabian Sea to the east, Djibouti to the west, and the Guardafui Channel, Socotra (Yemen), and Somalia to the south. In the northwest, it connects with the Red Sea through the Bab-el-Mandeb strait, and it connects with the Arabian Sea to the east. To the west, it narrows into the Gulf of Tadjoura in Djibouti.
The ancient Greeks regarded the gulf as one of the most important parts of the Erythraean Sea. It later came to be dominated by Muslims, as the area around the gulf converted to Islam. From the late 1960s onwards, there started to be an increased Soviet naval presence in the Gulf. The importance of the Gulf of Aden declined when the Suez Canal was closed, but it was revitalized when the canal was reopened in 1975, after being deepened and widened by the Egyptian government.
The waterway is part of the important Suez Canal shipping route between the Mediterranean Sea and the Arabian Sea in the Indian Ocean, with 21,000 ships crossing the gulf annually. This route is often used for the delivery of Persian Gulf oil, making the gulf an integral waterway in the world economy. Important cities along the Gulf of Aden include the namesake Aden in Yemen. Other Yemeni cities are Zinjibar, Shuqrah, Ahwar, Balhaf, Mukalla. On the Horn of Africa side, the cities of Djibouti, Berbera, and Bosaso.
Despite a lack of large-scale commercial fishing facilities, the coastline supports many isolated fishing towns and villages. The Gulf of Aden is richly supplied with fish, turtles, and lobsters. Local fishing takes place close to the shore; sardines, tuna, kingfish, and mackerel make up the bulk of the annual catches. Crayfish and sharks are also fished locally.
In antiquity, the modern-day Gulf of Aden was seen as an extension of the Erythraean Sea (Red Sea) Greek: ?, Erythrà Thálassa in Ancient Greek geography. The Greeks named several islands within the gulf, including Stratonis Insula, although it is no longer clear which existing islands had which Greek names.
In Abu'l-Fida's, A Sketch of the Countries (Arabic: ?), the present-day Gulf of Aden was called the Gulf of Berbera, which shows how important Berbera was in both regional and international trade during the medieval period.
Legendary navigator Ibn Majid referred to the Gulf of Aden as the Gulf of Berbera in his 15th century magnum opus The Book of the Benefits of the Principles and Foundations of Seamanship. In his description of the Somali coast and wider Indian Ocean he used the then contemporary reference to the Gulf as being named after Berbera like Abu'l-Fida before him. Berbera has been a prominent port since antiquity
The temperature of the Gulf of Aden varies between 15 °C (59 °F) and 28 °C (82 °F), depending on the season and the appearance of monsoons. The salinity of the gulf at 10 metres (33 ft) depth varies from 35.3 ? along the eastern Somali coast to as high as 37.3 ? in the gulf's center, while the oxygen content in the Gulf of Aden at the same depth is typically between 4.0 and 5.0 mg/L.
The Gulf of Aden is a vital waterway for shipping, especially for Persian Gulf oil, making it an integral waterway in the world economy. Approximately 11% of the world's seaborne petroleum passes through the Gulf of Aden on its way to the Suez Canal or to regional refineries. The main ports along the gulf are Aden, Balhaf, Bir Ali, Mukalla, and Shokra in Yemen; Djibouti City in Djibouti; Zeila, Berbera, Maydh and Las Khorey in Somaliland and Bosaso in Somalia.
In antiquity, the gulf was a thriving area of international trade between Ptolemaic Egypt and Rome in the west and Classical India, its Indonesian colonies, and Han China in the east. It was not limited to transshipment, as Yemeni incense, tortoiseshell, and other goods were in high demand in both directions. After Egyptian sailors discovered the monsoon winds and began to trade directly with India, caravan routes and their associated kingdoms began to collapse, leading to a rise in piracy in the area. The 1st-century Periplus of the Erythraean Sea documents one Egyptian captain's experiences during this era.
After the collapse of the Roman economy, direct trade ceased but the Awsan I port Crater, located just south of the modern city of Aden, remained an important regional center. In late antiquity and the early medieval period, there were several invasions of Yemen from Ethiopia; after the rise of Islam, the gulf permitted repeated migrations of northwest Africa by Arab settlers.
In the late 2000s, the gulf evolved into a hub of pirate activity. By 2013, attacks in the waters had steadily declined due to active private security and international navy patrols. India receives US$50 billion in imports and sends US$60 billion in exports through this area annually. Due to this, and for the sake of protecting the trade of other countries, India keeps a warship escort in this area.
A geologically young body of water, the Gulf of Aden has a unique biodiversity that contains many varieties of fish, coral, seabirds and invertebrates. This rich ecological diversity has benefited from a relative lack of pollution during the history of human habitation around the gulf. However, environmental groups fear that the lack of a coordinated effort to control pollution may jeopardize the gulf's ecosphere.Whales, dolphins, and dugongs were once common before being severely reduced by commercial hunts, including by mass illegal hunts by Soviet Union and Japan in 1960s to 70s. Critically endangered Arabian humpback whales were once seen in large numbers, but only a few large whales still appear in the gulf waters, including Bryde's whales,blue whales, and toothed whales inhabiting deep-seas such as sperm whales and tropical bottlenose whales.