The Alboran Sea is a high-stakes gateway between the Atlantic and the Mediterranean

Countries & Cities · Published 29 September 2026 Swipe more like this →

In short: As the westernmost reach of the Mediterranean, the Alboran Sea acts as a vital transition zone. Here, Atlantic and Mediterranean waters collide in a complex vertical gyre, creating a unique biological crossroads that supports everything from rare harbour porpoises to the Mediterranean's only known cold-water coral reef.

Geologically, the Alboran Sea is a site of intense, ongoing transformation. It sits atop the Alboran domain, where the African and Eurasian plates continue to interact. Deep-seated earthquakes, occurring as far down as 600 kilometres, signal that the subduction process that began when the ancient Tethys Ocean closed is still active today. The seafloor itself is a rugged landscape of sub-basins, seamounts, and the 180-kilometre-long Alboran Ridge, which extends southwest from the volcanic Isla de Alborán.

The sea functions as a massive hydraulic engine. Atlantic water flows eastward along the surface, while saltier Mediterranean water pushes westward in deeper currents, creating a rotary circulation pattern. This constant exchange makes the region a critical habitat. It hosts the largest population of bottlenose dolphins in the western Mediterranean and serves as a primary feeding ground for European loggerhead sea turtles. The surrounding Gibraltar Arc—comprising the Baetic Cordillera in Spain and the Rif Mountains in Morocco—mirrors this ecological richness, acting as a refuge for relict species that vanished elsewhere.

Human activity has long impacted this delicate balance. In 2003, the World Wildlife Fund highlighted the dangers posed by drift net fishing to local marine life. More recently, in 2023, a landmark agreement between the European Union, Morocco, and Algeria moved to protect the Cabliers Bank by banning bottom fishing. This measure is essential for preserving the region's unique biodiversity, which serves as a vital bridge between the Atlantic and Mediterranean ecological zones.

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