The conservation status of Mediterranean marine fishes was assessed using the IUCN Red List Categories and Criteria (IUCN 2001) during two workshops, in Istanbul (Turkey) in November 2007, and in Sète (France) in February 2008, as well as through correspondence with relevant experts. More than 25 experts participated in this assessment process. For those species that are endemic to the Mediterranean Sea, the regional assessments are also considered to be global assessments (i.e. representing the entire global population of the species). Non-endemic Mediterranean species (species that also have populations outside the Mediterranean Sea) were assessed at the regional level using the Guidelines for Application of IUCN Red List Criteria at Regional Levels (IUCN 2003a).
Mediterranean Marine Fish
Based on the IUCN’s Red List methodology, the assessment of the conservation status of 513 species and 6 subspecies, all Mediterranean native marine fishes, has helped identify those threatened with extinction at the regional level so that appropriate conservation actions can be taken. The geographical scope ranges from the Gibraltar Strait to the Marmara Sea, and excludes the Black Sea and the adjacent Atlantic waters.
Out of the 519 native marine fish species and subspecies included in this regional assessment, more than 8% (43 species) were classified under threatened categories (Critically Endangered, Endangered or Vulnerable). Of the 15 (3%) most threatened species (assessed as Critically Endangered, the highest threat category), 14 (93%) are sharks and rays. Thirteen species (2.5%) are listed as Endangered, 9 being sharks and rays, while 15 species (3%) are considered Vulnerable, with roughly equal numbers of sharks (8 species) and bony fishes (7 species). Additionally, 22 species (4%), amongst which 10 sharks and rays, are listed as Near Threatened, suggesting that they need to be closely monitored in case their conservation status becomes more serious.
Almost one-third (151 species) of Mediterranean marine fishes have been listed as Data Deficient, with not enough data available to evaluate their risk of extinction. The true proportion of threatened species might therefore be much higher, once more data become available.
A total of 74 species (14% of the assessed species) were considered to be endemic to the Mediterranean Sea (as defined in the report published). These endemic species are more frequently found in the western half of the Mediterranean Sea, especially around the Ligurian, Tyrrhenian and Tunisian coastlines. Four of these endemic fishes (5%) are threatened, including one ray (Leucoraja melitensis, Critically Endangered) and three bony fishes (Pomatoschistus tortonesei and Syngnathus taenionotus, both Endangered, and Opeatogenys gracilis, Vulnerable). Two endemic species (the speckled skate Raja polystigma and the narrow-snouted pipefish Syngnathus tenuirostris) are listed as Near Threatened. More than 40% (30 species) of Mediterranean endemic marine fishes have been also listed as Data Deficient, suggesting that they are either not very well known or threats within their ranges cannot be easily quantified. Data Deficient species may therefore be also threatened.
Over half of all Mediterranean marine fish are affected either directly or indirectly by fishing activities. Fishing is by far the most common threat to marine fish, affecting 33% of Mediterranean native species, with an additional 18% of specie being threatened by by-catch. Other important threats include pollution (affecting 7.5% of species), habitat loss (affecting 7.4% of species) and human disturbance (affecting 5% of species). Only a very low percentage (<1%) are affected by invasive alien species, which is remarkable considering the number of Lessepsian species (fish species native to the waters of the Suez Canal and often becoming invasive to the Mediterranean Sea) that have entered the Mediterranean basin.
- Many Mediterranean fishes, particularly sharks and rays and some of the larger-bodied commercially exploited bony fish species are more vulnerable due to their slow reproduction and life cycles.
- Protection and effective management plans are urgently required. Although some species are receive certain protection under national, regional or international conventions, the vast majority of threatened species are under no protection or effective management plans.
- Regional conservation management measures, such as the designation of ‘no-take zones’ or the creation of effective marine protected areas, should be implemented to reduce pressures on fish populations and safeguard critical fish habitats.
- Further funding and research into the status of endemic Mediterranean marine fish and Data Deficient species is a high priority. Limited data availability cannot justify the lack of management.
- Regional collaboration, especially among the southern and eastern Mediterranean countries, should be strengthened to fill the gaps on information available. The work carried out to produce this first evaluation of the threat status of native Mediterranean marine fishes can only be consolidated and updated as new information becomes available through cooperation among all Mediterranean countries.