Biodiversity in mountain groundwater: the Mercantour National Park (France) as a European hotspot

Abstract

ABSTRACT Mercantour National Park (France) is recognized as a highly heterogeneous region with extremely varied geology, geomorphology and climatology, resulting in an exceptional biodiversity. From a hydrogeological point of view, it is also an area organized into small and discontinuous aquifers, the obligate groundwater fauna of which (stygobionts) remains absolutely unknown. This work explores the species richness of groundwaters in the Mercantour National Park, using a sampling design at the catchment (six major valleys) and aquifer (aquifers in consolidated rocks and unconsolidated sediments) scales. A major finding of this study is the discovery of 44 species restricted to groundwater, of which 43 are new to the Park and ten are new to Science. Although a relatively small number of sites were sampled (53), the area may be considered as a new hotspot of groundwater biodiversity at the European level. The particular structure of the groundwater network, the high environmental heterogeneity of the reg...