an important biological corridor, within the national green infrastructure and the Pan-European ecological network. Consequently, it is classified as a Natura 2000 protected area. Currently there are between 150 and 200 species of benthic macroinvertebrates, but with few plant species (due to the greatly changing flow of the river). Water quality is considered good in the higher valley, in spite of the number of dams, which deprive the Durance of the power needed to carry sediment away. This quality was obtained thanks to actions of clean-up projects on the river itself and on the tributaries of the Luye and Calavon (also called le Coulon)). There remain some black spots in the valley (downstream from the Arkema factory at Château-Arnoux, below the confluence with the Calavon. The depth variation results in significant temperature variations, from seasonally; daily temperatures have of amplitude in the summer and in the winter. These are a significant factor in the biodiversity of the river. The dams in the valley have reduced the incidence of floods and so have allowed the colonisation of alluvial space by alder and poplar in riparian forests. The banks, although less wet, still accommodate 110 species of birds during the year, plus 82 species of migratory birds, which rest, feed and sometime reproduce. One-hundred-ten species of animal hibernate there. Avian diversity increased after the dams were built, but there was probably once a greater diversity. For some families of birds the number of individuals also increased. There are approximately 75 species of mammals in the Durance catchment area, including: Eurasian beaver, southwestern water vole, Eurasian water shrew, many species of bat (barbastelle (Barbastella barbastellus, large murine (Myotis myotis), large rhinolophe (Rhinolophus ferrumequinum), minioptère of Schreibers (Miniopterus schreibersi), small murine (Myotis blythii), small rhinolophe (Rhinolophus hipposideros), vespertilion with indented ears (Myotis emarginatus), and vespertilion of Capaccini (Myotis capaccinii)). invasive are becoming more problematic including coypu and the recently arrived muskrat. Otters have recently become extinct in the entire catchment area. The populations of algae and water plants (100 species on average) and water invertebrates (77 species) are more varied than before the dams compared with populations on the similar Asse and Buëch. Ludwigia, the primrose willow, is an invasive plant having gradually spread since 1986 in the stagnant water in dead gravel pits and ponds. There are only fourteen fish species, including some native species: souffia, south-west European nase and large populations of