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The Alboran Sea is the westernmost portion of the Mediterranean Sea

Mediterranean Sea

The Mediterranean Sea is a sea connected to the Atlantic Ocean surrounded by the Mediterranean region and almost completely enclosed by land: on the north by Anatolia and Europe, on the south by North Africa, and on the east by the Levant...

, lying between Spain

Spain

Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...

 on the north and Morocco

Morocco

Morocco , officially the Kingdom of Morocco , is a country located in North Africa. It has a population of more than 32 million and an area of 710,850 km², and also primarily administers the disputed region of the Western Sahara...

 and Algeria

Algeria

Algeria , officially the People's Democratic Republic of Algeria , also formally referred to as the Democratic and Popular Republic of Algeria, is a country in the Maghreb region of Northwest Africa with Algiers as its capital.In terms of land area, it is the largest country in Africa and the Arab...

 on the south. The Strait of Gibraltar

Strait of Gibraltar

The Strait of Gibraltar is a narrow strait that connects the Atlantic Ocean to the Mediterranean Sea and separates Spain in Europe from Morocco in Africa. The name comes from Gibraltar, which in turn originates from the Arabic Jebel Tariq , albeit the Arab name for the Strait is Bab el-Zakat or...

, which lies at the west end of the Alboran Sea, connects the Mediterranean with the Atlantic Ocean

Atlantic Ocean

The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...

.

Its average depth is 1461 feet (445.3 m) and maximum depth is 4920 feet (1,499.6 m).

The International Hydrographic Organization

International Hydrographic Organization

The International Hydrographic Organization is the inter-governmental organisation representing the hydrographic community. It enjoys observer status at the UN and is the recognised competent authority on hydrographic surveying and nautical charting...

 defines the limits of the Alboran Sea as follows:

On the West. The Eastern limit of the Strait of Gibraltar [A line joining Europa Point

Europa Point

Europa Point, also called Great Europa Point, is the southernmost point of Gibraltar. At the end of Rock of Gibraltar, the area is flat and occupied by such features as a playing field and a few buildings...

 to P. Almina

Península de Almina

The Península de Almina is a peninsula making up much of the eastern part of the Spanish city of Ceuta in Africa. It is dominated by the peak of Monte Hacho. The peninsula contains Ceuta's easternmost point, Punta Almina, and is connected to the rest of Ceuta by an isthmus barely 100 metres in...

 (35°54′N 5°18′W)].

On the East. A line joining Cape de Gata (Spain) to C. Fegalo (Africa) (35°36′N 1°12′W).

Surface currents in the Alboran Sea flow eastward, bringing water from the Atlantic into Mediterranean; deeper subsurface currents flow westward, carrying saltier Mediterranean water into the Atlantic. There is typically a rotary circulation, also known as a gyre

Gyre

A gyre in oceanography is any large system of rotating ocean currents, particularly those involved with large wind movements. Gyres are caused by the Coriolis Effect; planetary vorticity along with horizontal and vertical friction, which determine the circulation patterns from the wind curl...

, in the Alboran Sea as a result of this exchange of water. The Alboran Sea is a transition zone between the two seas, containing a mix of Mediterranean and Atlantic species. The Alboran Sea is habitat for the largest population of bottlenose dolphin

Bottlenose Dolphin

Bottlenose dolphins, the genus Tursiops, are the most common and well-known members of the family Delphinidae, the family of oceanic dolphins. Recent molecular studies show the genus contains two species, the common bottlenose dolphin and the Indo-Pacific bottlenose dolphin , instead of one...

s in the western Mediterranean, is home to the last population of harbour porpoise

Harbour Porpoise

The harbour porpoise is one of six species of porpoise. It is one of the smallest marine mammals. As its name implies, it stays close to coastal areas or river estuaries, and as such, is the most familiar porpoise to whale watchers. This porpoise often ventures up rivers, and has been seen...

s in the Mediterranean, and is the most important feeding grounds for loggerhead sea turtle

Loggerhead sea turtle

The loggerhead sea turtle , or loggerhead, is an oceanic turtle distributed throughout the world. It is a marine reptile, belonging to the family Cheloniidae. The average loggerhead measures around long when fully grown, although larger specimens of up to have been discovered...

s in Europe. The Alboran sea also hosts important commercial fisheries, including sardine

Sardine

Sardines, or pilchards, are several types of small, oily fish related to herrings, family Clupeidae. Sardines are named after the Mediterranean island of Sardinia, around which they were once abundant....

s and swordfish

Swordfish

Swordfish , also known as broadbill in some countries, are large, highly migratory, predatory fish characterized by a long, flat bill. They are a popular sport fish of the billfish category, though elusive. Swordfish are elongated, round-bodied, and lose all teeth and scales by adulthood...

. In 2003, the World Wildlife Fund raised concerns about the widespread drift net

Drift net

Drift netting is a fishing technique where nets, called drift nets, are allowed to float freely at the surface of a sea or lake. Usually a drift net is a gill net with floats attached to a rope along the top of the net, and weights attached to another rope along the foot of the net to keep the net...

 fishing endangering populations of dolphins, turtles, and other marine animals.

Several small islands dot the sea, including the Isla de Alborán

Isla de Alborán

The Isla de Alborán is a small islet in the Alborán Sea, part of the western Mediterranean, about 50 km north of the Moroccan coast and 90 km south of the province of Almería, Spain. A Spanish possession since 1540, it was taken from the Tunisian pirate Al Borani in the Battle of Alborán. It is...

. Most, even including those closer to the Moroccan shore are controlled by Spain.

An arc of mountains, known as the Gibraltar Arc

Gibraltar Arc

The Gibraltar Arc is a geological region corresponding to an arcuate orogen surrounding the Alboran Sea, between the Iberian Peninsula and Africa. It consists of the Betic Cordillera , and the Rif ....

, wraps around the northern, western, and southern sides of the Alboran Sea. The Gibraltar Arc is made up of the Baetic Cordillera

Baetic Cordillera

The Baetic System is the main system of mountain ranges in Spain. Located in southern and eastern Spain, it is also known as the Baetic Cordillera, Baetic Ranges or Baetic Mountains...

 of southern Spain and the Rif Mountains of Morocco. These mountains, known to ecologists as the Baetic-Rifan complex, are one of the Mediterranean's biodiversity hotspot

Biodiversity hotspot

A biodiversity hotspot is a biogeographic region with a significant reservoir of biodiversity that is under threat from humans.The concept of biodiversity hotspots was originated by Norman Myers in two articles in “The Environmentalist” , revised after thorough analysis by Myers and others in...

s; like the Alboran sea, the Baetic-Rifan complex is a transition between the Mediterranean and Atlantic (Macaronesia

Macaronesia

Macaronesia is a modern collective name for several groups of islands in the North Atlantic Ocean near Europe and North Africa belonging to three countries: Portugal, Spain, and Cape Verde...

n) ecologies. The moderating influence of the Atlantic has allowed many species in the Baetic and Rif mountains to survive the climatic fluctuations of the last few million years that caused them to become extinct elsewhere around the Mediterranean basin.