Harmelin, J.-G.; Boury-Esnault, N.; Fichez, R.; Vacelet, J.; Zibrowius, H. (2003). Peuplement de la grotte sous-marine de l'ile de Bagaud (parc national de Port-Cros, France, Méditerranée). Rapport scientifique du Parc national de Port-Cros. 19, 117-134.
Harmelin, J.-G.; Boury-Esnault, N.; Fichez, R.; Vacelet, J.; Zibrowius, H.
Peuplement de la grotte sous-marine de l'ile de Bagaud (parc national de Port-Cros, France, Méditerranée)
Rapport scientifique du Parc national de Port-Cros
Communities of a submarine cave at Bagaud Island, (Port-Cros National
Park, France, Mediterranean). The communities in the only submarine cave known in the national park of Port·Cros have been surveyed by SCUBA diving. This shallow cave (8 m) comprises two small chambers offering various degrees of darkness, low confinement, and an unusual production of manganese oxides from cracks in the back wall. Sessile
communities were dominated both in cover and species richness by sponges (47 species). Secondary dominants in cover included bryozoans (29 species), scleractinians (5 species) and serpulid and spirorbid polychaetes (18 species). Brachiopods (5 species) and molluscs (6 species) were subordinate components of the wall and roof fauna. Ten species of crustaceans (2 mysids and 8 decapods) and 19 fish species, including 11 resident species, were recorded visually. Despite limiting physical characters (small cave size, Shallow depth, exposure), all these groups included typical components of dark cave
communities that also occur on the continental slope, as well as rare or poorly known species. These assemblages were also characterised by the absence of some species among the most common components of other NW Mediterranean cave communities and which occur locally in deeper shaded habitats. The production of manganese oxides in the back chamber may possibly be responsible of part 01 these exclusions (e.g. cyclostome bryozoans), and of abnormality affecting spicules in some siliceous sponge species.