Memorias de la RSEHN (segunda época)

El presente documento proporciona una visión sobre el actual estado de conservación de las especies de la cuenca del Mediterráneo según los resultados de las evaluaciones de la Lista Roja de la Unión Internacional para la Conservación de la Naturaleza (UICN), las principales causas de amenaza identifi cadas y acciones de conservación necesarias en la región. Los resultados presentados en Cඎඍඍൾඅඈൽ et al. (2008) muestran que aproximadamente una quinta parte (19%) de las especies evaluadas a escala global y regional se encuentran en peligro de extinción. Más de la mitad de los peces de agua dulce endémicos, delfi nes y ballenas se encuentran en peligro de extinción, hasta el 42% de los peces cartilaginosos, más de un tercio de los cangrejos de agua dulce y más de un cuarto de los anfi bios, casi una quinta parte de las libélulas, un 14% de los mamíferos, el 13% de los reptiles, el 5% de las aves y el 15% de las plantas acuáticas. El incremento de la densidad de la población y del turismo en este punto caliente de biodiversidad contribuyen a potenciar el riesgo de extinción de estas especies al incrementarse la presión sobre los ecosistemas derivada de las actividades humanas. Las principales amenazas para la conservación de la biodiversidad regional son la pérdida, fragmentación y degradación del hábitat, la contaminación, la sobreexplotación de los recursos y las especies invasoras introducidas.

The outstanding fl ora biodiversity of the Mediterranean, with between 15,000 and 25,000 species, 60% of which are unique to the region, has given this area the recognised status of a global biodiversity hotspot (Mඒൾඋඌ et al., 2000). In addition to this relevant number of plant species, about one third of Mediterranean fauna is endemic. Out of the total number of taxa assessed, two out of each three amphibian species were found to be endemic, more than half of the freshwater crabs, 48% of the reptiles, a quarter of the mammals, 14% of the dragonfl ies, 4% of the sharks and rays, 3% of the birds and a 32% of the aquatic plants. In 2008, Cඎඍඍൾඅඈൽ et. al. pointed out that, within the 1,912 species of amphibians, birds, cartilaginous fi shes, endemic freshwater fi shes, crabs and crayfi sh, mammals, dragonfl ies and reptiles that have been assessed to date in the Mediterranean region, about 19% are threatened with extinction, i.e., are listed as one of the three categories of threat under the IUCN (International Union for Conservation of Nature) Red List of Threatened SpeciesTM: 5% Critically Endangered (CR), 7% Endangered (EN) or 7% Vulnerable (VU). The extinction at a global level of at least 16 irreplaceable species from the region confi rm the loss of an important part of the global biological heritage, including a bird, Canary Islands Oystercatcher Haematopus meadewaldoi, a mammal, the Sardinian Pika Prolagus sardus and seven endemic freshwater fi sh (Tristramella intermedia, Tristramella magdelainae, Alburnus akili, Chondrostoma scodrense, Mirogrex hulensis, Telestes ukliva and Salmo pallaryi. Habitat loss and degradation, for example through dam construction and coastal infrastructural development, are the major causes of Mediterranean species’ high risk of extinction. Population growth and tourism contribute to the increased pressures of human activities on species through pollution, droughts, invasive alien species introduction and overexploitation (over-fi shing, -hunting and -harvesting), which have been identifi ed as important factors in the decline of Mediterranean biodiversity. Regional and international experts have identifi ed key conservation measures needed to alleviate the risk of extinction in the Mediterranean, which should be applied at different scales (global, regional, local) and support the fulfi lment of the regional, global conventions as well as the multilateral agreements. Urgent conservation actions are needed to preserve the future of the Mediterranean diversity. Enforcement of adequate legislation as well as sustainable management of exploited species site protection, through establishment of protected areas networks, and conservation of the wider environment (Ecosystem approach) should be a priority. Communication, education, monitoring and research are key measures to be promoted in the region. Urgent action is needed to protect Mediterranean freshwater ecosystems, which are under severe pressure –more than half of the endemic freshwater fi shes are threatened–. There are geographic concentrations of freshwater threatened fauna in several regions, in particular the Iberian Peninsula, the Balkans and the North-Eastern Mediterranean. Distribution patterns of terrestrial threatened species display a fragmented mosaic of areas facing particularly serious threats in a region that has a natural and cultural mixture of landscapes that favoured the evolution of an extraordinary diversity of species. Marine biodiversity is still very poorly understood in the region, with a high number of species yet to be assessed or listed as Data Defi cient.