Diversity and distribution of azooxanthellate corals in the Colombian Caribbean

Abstract

During the last decade, knowledge of azooxanthellate corals in the Colombian Caribbean has increased through exploration campaigns by the Marine and Coastal Research Institute (INVEMAR). The distribution of 142 species of corals, including hard corals (Scleractinia 64 species), black corals (Antipatharia 18 species), and soft corals (Octocorallia 60 species) is assessed. Statistical analyses were performed to examine the coral species distribution through a geographic gradient (210 stations in 8 sectors) and a bathymetric range (10-520 m depth). Four principal patterns were observed: (1) northeastern distribution (46 species), (2) southwestern distribution (11 species), (3) association with azooxanthellate coral bioherms (37 species), and (4) widespread (44 species). In addition, 4 species were only found around the San Andres Archipelago (insular pattern). Two main oceanographic factors were identified to play a role in the northeast versus southwest coral fauna separation, La Guajira upwelling system and the Magdalena River influx. These patterns appear to be depth-related, since the separation between northeast and southwest was mainly shown by the shallow-water coral fauna, whereas most of the deep-water corals (>200 m depth) were widely distributed along the Colombian Caribbean coastline. These data were also analyzed from a conservation perspective in order to propose new strategies for the protection of the Colombian Caribbean coral fauna. © 2012 The Author(s).