Threatened Freshwater Fishes of the Mediterranean Basin Biodiversity Hotspot: Distribution, extinction risk and the impact of hydropower. Euronatur and Riverwatch.
Creators: name: Freyhof, Jörg
name: Bergner, Laura
name: Ford, Matt
Publisher: name: Museum für Naturkunde Berlin (MfN) - Leibniz Institute for Evolution and Biodiversity Science
Year: 2020
Subjects: Threatened Freshwater Fishes
Mediterranean Basin Biodiversity Hotspot

description: The Mediterranean Basin Biodiversity Hotspot is among the most biologically diverse regions worldwide and renowned for its richness of endemic freshwater species. But the hotspot’s lakes, rivers and wetlands are seriously threatened by an unprecedented boom in hydropower development. As a result, aquatic ecosystems have become increasingly degraded due to construction of dams and other infrastructure, compounded by a range of other threats. Advocates of this flawed development model repeatedly overestimate economic benefits and ignore severe environmental consequences. In particular, the impacts of small (10 MW) hydropower plants are disproportionately high when offset against their minuscule contribution to global energy production. At least 5,269 hydropower plants are already operating in the region, with 202 currently under construction. A further 6,393 are proposed, including 5,962 small projects, while 1,579 exist and 2,091 are planned within the boundaries of national parks, biosphere reserves, and other protected areas. In order to anticipate the biodiversity impact of this widening hydropower infrastructure it is essential to understand where threatened species are distributed. This report presents detailed range maps for all 251 freshwater fish species presently recognised as threatened in the Mediterranean Basin Biodiversity Hotspot alongside an updated evaluation of their respective extinction risks. The results suggest that an alarming 63% of all threatened freshwater fish species have already been driven closer to extinction by existing hydropower plants, with 55% of all Critically Endangered species highly impacted. Should hydroelectric expansion in the region go ahead as planned, 74% of all threatened freshwater fish species will be negatively impacted, with 65% set to decline due to small projects alone. At least seven of these could become globally extinct in the wild as a result. Hydropower projects, particularly small schemes, are therefore the most important driver of potential fish species extinctions in the Mediterranean Basin Biodiversity Hotspot. Impoundments created by dams and other hydroelectric infrastructure are also the key pathway by which non-native fish species, another major cause of freshwater fish declines, enter fluvial ecosystems. Moreover, if the hydroelectric schemes planned in the Mediterranean Basin Biodiversity Hotspot are implemented, nations will be unable to comply with the United Nations 2030 Agenda for Sustainable Development or binding international biodiversity targets agreed by parties to the Convention on Biological Diversity and European Union member states. There is an urgent need to mitigate the escalating ecological damage triggered by the hydropower binge through preservation and restoration of free-flowing rivers. Rapid and significant action underpinned by sound scientific evidence is required to safeguard freshwater ecosystems and the incredibly rich biodiversity they support throughout the region. By improving the state of the natural environment, the impacts of ongoing climate change would also be reduced. It is hoped that this report will help inform nature conservation, governments and policy-makers to make the right political, financial and consumer choices to reverse the trend of freshwater biodiversity decline throughout the Mediterranean Basin Biodiversity Hotspot.