Benthic Fauna of Littoral and Deep-Sea Habitats of the Alboran Sea: A Hotspot of Biodiversity

Abstract

Benthic habitats, as well as their associated biota, have been studied in the Alboran Sea since the nineteenth century, with a very significant increase of knowledge in the last five decades. The geographical location of the Alboran Sea between three different biogeographical regions, the complex oceanography and the heterogeneous seafloor promote the coexistence of a wide diversity of habitat-forming species and, therefore, of habitat types. Some of these habitats host very complex communities in comparison to similar ones that are located northwards in the Atlantic Ocean or eastwards in the Mediterranean Sea. Moreover, some of those habitats are considered to be threatened or are experiencing very strong declines during this last decade and are probably extinct nowadays (e.g. Zostera marina beds). General knowledge of the associated biota is larger for those habitats of shallow waters in comparison to those of the deep sea and for those located in the northern sector in relation to those of the southern sector of the Alboran Sea. In most habitats, only some components of the associated biota have been studied, and there is a general lack of information for specific groups (e.g. meiofauna, Platyhelminthes, etc.).