Intérêt biogéographique de la côte basque rocheuse

During recent decades, works on rocky shore biodiversity have been multiplied in the southern part of the Bay of Biscay and more precisely on intertidal and subtidal area were communities present a great interest. Necessity of conservation of coastal habitats and their communities and a growing pressure on coastal environments explain awareness of services provided by these ecosystems. Those communities are very sensitive to water quality change. Moreover, since the beginning of the XXI century various European directives require a good ecological status of coastal waters and conservation of their communities : Water Framework Directive (WFD), Marine Strategy Framework Directive (MSFD) and conservation of habitats with Directive Habitat Fauna and Flora (DHFF).... Integrated environmental status assessment approach is needed for this requirement in front of specific component at the regional scale of the Bay of Biscay. This analyze, at this regional scale, bring a particular interest to follow some biological groups in front of their ecological sensitivity. Among them, some example are listed like algae, invertebrate as species of mollusc opistobranch and fishes of the family blennidae are targets of interest for future monitoring. The biogeographic specificity of species of these groups is to present strong ecological requirements, in a trophic point of view for example, as well as boundary in local distribution in the southern part of the Bay of Biscay. Thus, monitoring of their distribution and abundance should be a relevant indicator of environmental change. If the presence of individuals is relatively easy to implement, monitoring in terms of abundance are more complex to develop to obtain representative data in coastal areas. The mobile character of the individual and their high location variability based on fluctuating environmental conditions is a challenge that needs to be considered. Interest concerns both the development of their number and their migration to the north for species in northern limit, and/or disappearance for species in southern distribution limits. Moreover, acquisition of knowledge on the taxonomy of local species is a way to improve biodiversity knowledge and assessment of global change as climatic change.