Biogeographical and Macroecological Context of the Alboran Sea

A complex geological history, a critical geographical location, and the existence of permeable biogeographical barriers at both ends of its longitudinal range, the Strait of Gibraltar and the hydrographic front between Almeria and Oran, have shaped the Alboran Sea as a biogeographical entity at the crossroads between the Atlantic Ocean and the Mediterranean proper. The Alboran biota is composed mainly of four biotic elements, endemic to the Mediterranean, Atlanto-Mediterranean, African, and Boreal, and also includes a few species strictly endemic to the Alboran Sea, which have a high conservation value. In a macroecological context, the Alboran Sea is a pathway that connects Mediterranean and Atlantic waters, receives the runoff from the Iberian Peninsula and the North of Africa, and is affected by the macroclimatic oscillations of the Northern hemisphere, all of which modify local populations. The effects of climate change on the whole Mediterranean Sea, and the changes in species distribution due to global change and the intense human use in the zone, are transforming the Alboran Sea. Furthermore, this transition zone has turned into a critical area for monitoring biological invasions of species of tropical Atlantic origin or coming from the Indian and Pacific oceans following Lessepsian migrations.