Change in the climate and in the biodiversity-conservation paradigm - The case of diadromous fish

Abstract

The conservation of biodiversity is a recent concept which is mainly based on European directives and international conventions which do not consider the dynamic nature of ecological systems. Up to now, the aim was to restore a historical situation judged more satisfactory for a species, a habitat or an ecosystem. The ongoing climate change imposes a change of strategy because in some cases it will not be possible to restore the previous situation (temperature, precipitations). It is necessary to revise the geographical location of planned conservation measures and to amplify the measures facilitating the repositioning of species (improvement of connectivity). Beyond the questions on the climate scenarios used as input, these results overturn current rationales and raise serious questions concerning certain specific measures when projection models do not guarantee survival conditions for a particular species.