Estimating the biodiversity of the East Antarctic shelf and oceanic zone for ecoregionalisation: example of the ichthyofauna of the CEAMARC (Collaborative East Antarctic Marine Census) CAML surveys

Ecoregions are defined in terms of community structure in function of abiotic or even anthropogenic forcing. They are mesoscale structures defined on the potential habitat of species or predicted communities geographic extent. We assume that they can be more easily defined for long-lived species such as benthos or neritic fish in the marine environment. Uncertainties exist for the pelagic realm because of its higher variability, plus little is known about the meso- and bathypelagic zones. A changing environment and modifications of habitats will probably drive new communities from plankton to fish or top predators. We need based-line studies such as those of CAML, databases like SCAR-MarBIN and tools for integrating all of these observations. Our objective is to understand the biodiversity patterns in the Southern Ocean and how these might change.