> Despite our rapidly improved understanding of their AUTHORS MEDITERRANEAN SHARKS AND widespread overexploitation in the Mediterranean basin5,6, no effective chondrichthyan-focused management measures Nicholas K. Dulvy, IUCN Shark Specialist Group, RAYS FACE AN EXTINCTION CRISIS have been successfully implemented, nor enforced. Stock Simon Fraser University, Burnaby, Canada. assessments are underway, however assessments are not At least 53% of the sharks, rays and chimaeras David J. Allen, IUCN Global Species management measures, but essential precursors to set native to the Mediterranean Sea are at risk catch limits for those more productive species that could Programme, The David Attenborough be brought into sustainability. In 2010 and 2011 the General Building, Cambridge, United Kingdom. of extinction and require urgent action to Fisheries Commission for the Mediterranean (GFCM), The Conservation Status of Gina M. Ralph, IUCN Global Species conserve their populations and habitats. the regional sheries management organisation for the Programme, Marine Biodiversity Unit, Old Bullray, Pteromylaeus bovinus Mediterranean Sea, adopted ad hoc measures to reduce Dominion University, Norfolk, United States. © La Ciutat De Les Arts I Les Ciències, Valencia This publication summarizes the outcomes of a signi cant collaboration Sharks, Rays and Chimaeras the bycatch of pelagic sharks such as Thresher, Mako and Hammerhead sharks. In 2012, the GFCM banned nning Rachel H.L. Walls, IUCN Shark Specialist Group, between the IUCN Centre for Mediterranean Cooperation, the IUCN practices in the Mediterranean and Black seas and also Simon Fraser University, Burnaby, Canada. Global Species Programme and the IUCN Shark Specialist Group in the Mediterranean Sea prohibited the capture and sale of the sharks and rays who, together with experts from across the Mediterranean region, species listed in Annex II of the Specially Protected Areas and Biological Diversity in the Mediterranean (SPA/BD) Protocol have worked to bring together available information on the species of the Barcelona Convention. In 2010-2013 the GFCM of Chondrichthyans found in the Mediterranean Sea and produce carried out a three-year research programme to improve assessments for the IUCN Red List of Threatened SpeciesTM. the knowledge and assess the status of elasmobranchs in the region, and it continues to work in close collaboration This assessment was undertaken through the Great White Shark, with the regional experts to contrast sharks and rays Carcharodon carcharias Mediterranean Red List Initiative, which is coordinated populations’ decline. However only a few of its Parties © Peter Verhoog / Dutch Shark Society by the IUCN Centre for Mediterranean Cooperation. have taken concrete domestic action to implement these recommendations. Prohibitions on catch, such as required for the species listed on the Barcelona Convention, should Sandbar Shark, be urgently implemented to avoid further declines and Carcharhius plumbeus extinctions. The IUCN Shark Specialist Group and © Tahsin Ceylan the Shark Trust are working together to ensure implementation of protections for all three species of Angel Shark. Rough Skate, Raja radula REFERENCES © Tahsin Ceylan 1. Dulvy, N.K. et al. 2014. Extinction risk and conservation of the world’s sharks and rays. eLife 3: e00590. 2. Cavanagh, R.D. and Gibson, C. 2007. Overview of the Conservation Status of Cartilaginous Fishes (Chondrichthyans) in the Mediterranean Sea. IUCN Species Survival Commission Shark Specialist Group, Gland, Switzerland and Malaga, Spain. 3. Camhi, M.D., Fowler, S.L., Musick, J.A., Bräutigam, A. and Fordham, S.V. 1998. Sharks and their relatives: ecology INTERNATIONAL UNION FOR CONSERVATION OF NATURE and conservation. IUCN/SSC Shark Specialist Group, Gland, Switzerland and Cambridge, UK. IUCN Centre for Mediterranean Cooperation 4. Notarbartolo-Di-Sciara, G. 2014. Sperm whales, Physeter macrocephalus, in the Mediterranean Sea: a summary of status, Marie Curie, 22. 29590 - Campanillas (Málaga) Spain threats, and conservation recommendations. Aquatic Conservation: Marine and Freshwater Ecosystems 24: 4-10. iucnmed@ iucn.org | Tel +34 95 202 84 30 | Fax +34 95 202 81 45 5. Vasilakopoulos, P., Maravelias, C.D. and Tserpes, G. 2014. The Alarming Decline of Mediterranean Fish Stocks. www.iucn.org/mediterranean Current Biology 24(14): 1643-1648. 6. Osio, G.C., Orio, A. and Millar, C.P. 2015. Assessing the vulnerability of Mediterranean demersal stocks and predicting exploitation status of un-assessed stocks. Fisheries Research 171: 110-121. Core support to the IUCN Centre for Mediterranean Cooperation is provided by: CITATION: Dulvy, N.K., Allen, D.J., Ralph, G.M. and Walls, R.H.L. (2016). The conservation status of Sharks, Rays and Chimaeras in the Mediterranean Sea [Brochure]. IUCN, Malaga, Spain. ©2016 International Union for Conservation of Nature Chondrichthyan Crisis in the Mediterranean Sea An analysis of threat levels across all sharks, rays and Furthermore, there is no sign of improvement in the The principal driver of decline and local extinction FIGURE 1 FIGURE 4 Summary of the Red List status of Chondrycthyans Historical species richness of Chondrichthyans chimaeras has revealed the Mediterranean Sea as a status of Mediterranean Chondrichthyans more than a is overfishing. Most species are taken as retained in the Mediterranean Sea. within the Mediterranean0° Sea. 10°E 20°E 30°E key hotspot of extinction risk1. Seventy seven species decade since they were fi rst assessed. We can track valuable bycatch in small-scale and large-scale trawl THE PRINCIPAL DRIVER OF 0° 10°E 20°E 30°E are recorded from the Mediterranean Sea, however changes in status of Chondrichthyans by comparing and net multispecies fisheries (Figure 3). Oceanic IUCN Red List Category Number of Species 45°N DECLINE AND LOCAL EXTINCTION of these, four species are considered to be either these fi ndings to the fi rst Mediterranean Sea Red List pelagic sharks are taken as retained secondary Extinct (EX) 0 2 vagrant or probably vagrant, or Lessepsian immigrants assessment in 2007 to this most recent assessment bycatch in longline fisheries targeting swordfishes Regionally Extinct (RE) 0 45°N IS OVERFISHING. Most species are from the Red Sea; they are the Spinner Shark in 2016. There were no genuine improvements in and tunas. More recently, there is concern over the Critically Endangered (CR) 20 40°N taken as retained valuable bycatch (Carcharhinus brevipinna), the Reticulate Whipray status for the 73, whereas the status of 11 species escalating targeting of pelagic sharks as tunas and Endangered (EN) 11 40°N (Himantura uarnak), the Great Hammerhead (Sphyrna worsened by at least one Red List Category. swordfishes are increasingly regulated. The status in small-scale and large-scale trawl Vulnerable (VU) 8 mokarran) and the Scalloped Hammerhead (Sphyrna of several pelagic sharks has worsened, including: 35°N Near Threatened (NT) 9 and net multispecies fisheries lewini). These four species have been excluded as Basking Shark, White Shark, Blue Shark, and Smooth 35°N Least Concern (LC) 12 Not Applicable for the Mediterranean region. Three Hammerhead Sharks. Bycatch volumes and species Species Speciesper 100 km2 per 100 km2 Data Decient (DD) 13 30°N 1 - 12.0 species are endemic to the Mediterranean Sea and composition are poorly documented and data are 30°N 1 - 12.0 12.1 - 29.0 More recently, there has been a significant 12.1 - 29.0 Total number of species assessed 73 29.1 - 46.0 found nowhere else – Maltese Skate (Leucoraja rarely incorporated into national and international 29.1 - 46.0 decline in species richness throughout 46.146.1 - 57.0- 57.0 melitensis; CR), Rough Skate (Raja radula; EN), and (FAO) statistics, therefore numbers of sharks caught * This table does not include the four vagrant or Lessepsian migrant species 57.157.1 - 69.0- 69.0 0 250 5000 250 1,000500km the1,000 kmMediterranean Sea due to increasing that have been considered Not Applicable (NA) for the Mediterranean region 25°N25°N the Speckled Skate (Raja polystigma; LC). More than as bycatch can only be crudely estimated3. Despite threats and local extinctions. Historically, half of the species assessed, 39 of 73 species, are being banned in 2002, illegal driftnetting is intense the number of threatened species regionally threatened; 31 are most imperilled in the and widespread throughout the Mediterranean 0° 10°E 20°E 30°E was very high with as many as 33 to 38 Critically Endangered (20 species) and Endangered Sea, e.g. fleets from Algeria, Italy, Morocco, Turkey, 2 FIGURE 2 FIGURE 5 threatened species found in 100 km cells in (11) categories (Figure 1). On a global scale, of the among others, continue to fish illegally with pelagic Distribution of Data Deficient Chondrichthyans Distribution of threatened (CR, EN, and VU) the coastal waters of the western and central 4 within the Mediterranean Sea. Chondrichthyans0° within the Mediterranean10°E Sea. 20°E 30°E 20 species of sharks, rays and chimaeras that have Angular Rough Shark, driftnets , and thus is likely to be an important and 45°N Mediterranean Sea (Figure 5). Threat levels are been assessed as Critically Endangered, seven have Oxynotus centrina largely hidden source of mortality for sharks. 0° 10°E 20°E 30°E 0° 10°E 20°E 30°E also high throughout the eastern Mediterranean some part of their distribution in the Mediterranean © Tahsin Ceylan 45°N Sea, with as many as 8 to 18 threatened species per Squatina Sea. Of the other 13 regionally CR species, the Historically, the diversity of chondrichthyans was 100 km2. No country has fewer than 29 threatened oculata Mediterranean Sea part of their population is more greatest in the western Mediterranean Sea, particularly 40°N45°N 45°N © Marc species within its Exclusive Economic Zone. Dando / threatened than the remainder of their global range. in the coastal waters of Morocco, Algeria, and 40°N Shark NO SIGN OF IMPROVEMENT Trust There is Tunisia, which harbour between 57 and 69 species 40°N 40°N This substantial change in species richness The level of threat may be worse because uncertainty in the status of Mediterranean (Figure 4).
Details
-
File Typepdf
-
Upload Time-
-
Content LanguagesEnglish
-
Upload UserAnonymous/Not logged-in
-
File Pages14 Page
-
File Size-