Spatial variability of Chondrichthyes in the northern Mediterranean




fish, Chondrichthyes, bottom trawl surveys, distribution, abundance, Mediterranean


Thanks to the availability of the MEDITS survey data, a standardized picture of the occurrence and abundance of demersal Chondrichthyes in the northern Mediterranean has been obtained. During the spring-summer period between 2012 and 2015, 41 Chondrichthyes, including 18 sharks (5 orders and 11 families), 22 batoids (3 orders and 4 families) and 1 chimaera, were detected from several geographical sub-areas (GSAs) established by the General Fisheries Commission for the Mediterranean. Batoids had a preferential distribution on the continental shelf (10-200 m depth), while shark species were more frequent on the slope (200-800 m depth). Only three species, the Carcharhiniformes Galeus melastomus and Scyliorhinus canicula and the Torpediniformes Torpedo marmorata were caught in all GSAs studied. On the continental shelf, the Rajidae family was the most abundant, being represented in primis by Raja clavata and then by R. miraletus, R. polystigma and R. asterias. The slope was characterized by the prevalence of G. melastomus in all GSAs, followed by S. canicula, E. spinax and Squalus blainville. Areas under higher fishing pressure, such as the Adriatic Sea and the Spanish coast (with the exception of the Balearic Islands), show a low abundance of chondrichthyans, but other areas with a high level of fishing pressure, such as southwestern Sicily, show a high abundance, suggesting that other environmental drivers work together with fishing pressure to shape their distribution. Results of generalized additive models highlighted that depth is one of the most important environmental drivers influencing the distribution of both batoid and shark species, although temperature also showed a significant influence on their distribution. The approach explored in this work shows the possibility of producing maps modelling the distribution of demersal chondrichthyans in the Mediterranean that are useful for the management and conservation of these species at a regional scale. However, because of the vulnerability of these species to fishing exploitation, fishing pressure should be further incorporated in these models in addition to these environmental drivers.


Download data is not yet available.


Abella A.J., Serena F. 2005. Comparison of Elasmobranch Catches from Research Trawl Surveys and Commercial Landings at Port of Viareggio, Italy, in the Last Decade. J. Northw. Atl. Fish. Sci. 35: 345-356.

Anastasopoulou I., Mytilineou C., Makantasi P., et al. 2018. Life history aspects of two species of the Squalus genus in the Eastern Ionian Sea. J. Mar. Biol. Ass. U.K. 98: 937-948.

Anonymous. 2017. MEDITS Handbook. Version n. 8, MEDITS Working Group, 177 pp.

Baino R., Serena F., Ragonese S., et al. 2001. Catch composition and abundance of elasmobranchs based on the MEDITS program. Rapp. Comm. Int. Mer Médit. 36: 234.

Barría C., Navarro J., Coll M., et al. 2015. Morphological parameters of abundant and threatened chondrichthyans of the northwestern Mediterranean Sea. J. Appl. Ichthyol. 31: 114-119.

Bellodi A., Porcu C., Cau A., et al. 2018. Investigation on the genus Squalus in the Sardinian waters (Central-Western Mediterranean) with implications on its management. Medit. Mar. Sci. 19: 256-272.

Bertrand J.A., Gil de Sola L., Papaconstantinou C., et al. 2000. An international bottom trawl survey in the Mediterranean: the Medits programme. In Bertrand J.A., Relini G. (eds). Demersal resources in the Mediterranean. Proceedings of the symposium held in Pisa, 18-21 March 1998. Actes de Colloques 26: 76- 93. Ifremer, Plouzané.

Bertrand J.A., Gil De Sola L., Papaconstantinou C., et al. 2002. The general specifications of the Medits surveys. Sci. Mar. 66: 9-17.

Bonello J., Bonnici L., Ferrari A., et al. 2016. Not all that clear cut: Intraspecific morphological variability in Squalus blainville (Risso, 1827) and implications for identification of the species. J. Mar. Biol. Assoc. U.K. 96: 1585-1596.

Bornatowski H., Braga R.R., Vitule J.R.S. 2013. Shark mislabeling threatens biodiversity. Science 340: 923. PMid:23704548

Bottari T., Busalacchi B., Profeta A., et al. 2014. Elasmobranch Distribution and Assemblages in the Southern Tyrrhenian Sea (Central Mediterranean). J. Aquac. Res. Develop. 5: 216.

Bradai N.M, Saidi B., Enajjar S. 2018. Overview on Mediterranean Shark's Fisheries: Impact on the Biodiversity. In: Türko?lu M., Önal U., Ismen A. (eds). Marine Ecology - Biotic and Abiotic Interactions. pp. 211-230.

Camhi M.D., Fowler S.L., Musick J.A., et al. 1998. Sharks and their relatives: ecology and conservation. IUCN/SSC Shark Specialist Group, Gland, Switzerland and Cambridge, UK. iv + 39 pp.

Carbonell A., Alemany F., Merella P., et al. 2003. The by-catch of sharks in the western Mediterranean (Balearic Islands) trawl fishery. Fish. Res. 61: 7-18.

Cariani A., Messinetti S., Ferrari A., et al. 2017. Improving the Conservation of Mediterranean Chondrichthyans: The ELASMOMED DNA Barcode Reference Library. PLoS ONE 12: e0170244. PMid:28107413 PMCid:PMC5249125

Cavanagh R.D., Gibson C. 2007. Overview of the conservation status of cartilaginous fishes (Chondrichthyans) in the Mediterranean Sea. IUCN, 42 pp.

Clarke S.C., McAllister M.K., Milner-Gulland E.J., et al. 2006. Global estimates of shark catches using trade records from commercial markets. Ecol. Lett. 9: 1115-1126. PMid:16972875

Coll M., Santojanni A., Palomera I., et al. 2009. Food-web changes in the Adriatic Sea over the last three decades. Mar. Ecol. Progr. Ser. 381: 17-37.

Colloca F., Enea M., Ragonese S., et al. 2017. A century fishery data documenting the collapse of smooth-hounds (Mustelus spp.) in Mediterranean Sea. Aquat. Conserv. 27: 1145-1155.

Compagno L.J.V. 1990. Alternative life-history styles of cartilaginous fishes in time and space. Env. Biol. Fish. 28: 33-75.

Damalas D., Vassilopoulou V. 2011. Chondrichthyan by-catch and discards in the demersal trawl fishery of the central Aegean Sea (Eastern Mediterranean). Fish. Res. 108: 142-152.

Davidson L.N.K., Krawchuk M.A., Dulvy N.K. 2016. Why have global shark and ray landings declined: Improved management or overfishing? Fish Fish. 17: 438-458.

Dent F., Clarke S. 2015. State of the global market for shark products. FAO Fisheries and Aquaculture Technical Paper No. 590. Rome, FAO. 187 pp.

Dulvy N.K., Fowler S.L., Musick J.A., et al. 2014. Extinction risk and conservation of the world's sharks and rays. eLife 3: e00590. PMid:24448405 PMCid:PMC3897121

Dulvy N.K., Allen D.J., Ralph G.M., et al. 2016. The conservation status of Sharks, Rays and Chimaeras in the Mediterranean Sea. IUCN, Malaga, Spain.

El Kamel-Moutalibi O., Mnasri-Sioudi N., Rafrafi-Nouira S., et al. 2014. Additional records of a rare elasmobranch species, sharpnose seven-gill shark Heptranchias perlo (Hexanchidae) off the northern Tunisian coast (Central Mediterranean). Ann. Ser. Hist. Nat. 2: 99-106.

Eschmeyer W.N., Fricke R., van der Laan R. (eds). 2018. Catalog of fishes: Genera, Species. catalog/fishcatmain.asp

FAO. 2010. The state of world fisheries and Aquaculture 2010. Food and Agriculture organization of the United Nations. Rome, 197 pp.

FAO. 2016. The State of Mediterranean and Black Sea Fisheries. General Fisheries Commission for the Mediterranean. Rome, 134 pp.

Farrugio H., Oliver P., Biagi F. 1993. An overview of the history, knowledge, recent and future research trends in Mediterranean fisheries. Sci. Mar. 57: 105-119.

Ferretti F., Myers R.A., Serena F., et al. 2005. Long term dynamics of chondrichthyan fish community in the upper Tyrrhenian Sea. ICES CM Documents 25: 1-34.

Ferretti F., Worm B., Britten G.L., et al. 2010. Patterns and ecosystem consequences of shark declines in the ocean. Ecol. Lett. 13: 1055-1071. PMid:20528897

Ferretti F., Osio G.C., Jenkins C.J., et al. 2013. Long-term change in a meso-predator community in response to prolonged and heterogeneous human impact. Sci. Rep. 3: 1057. PMid:23308344 PMCid:PMC3541648

Follesa M.C., Porcu C., Cabiddu S., et al. 2011. Deep-water fish assemblages in the central-western Mediterranean (south Sardinian deep-waters). J. Appl. Ichthyol. 27: 129-135.

Fortibuoni T., Borme D., Franceschini G., et al. 2016. Common, rare or extirpated? Shifting baselines for common angelshark, Squatina squatina (Elasmobranchii: Squatinidae), in the Northern Adriatic Sea (Mediterranean Sea). Hydrobiologia 772: 247-259.

Fowler S.L., Reed T.M., Dipper F.A. 2002. Elasmobranch Biodiversity, Conservation and Management. Proceedings of the International Seminar and Workshop, Sabah, Malaysia, July 1997. IUCN SSC Shark Specialist Group, Gland, Switzerland and Cambridge, UK. 258 pp.

Frodella N., Cannas R., VelonàA., et al. 2016. Population connectivity and phylogeography of the Mediterranean endemic skate Raja polystigma and evidence of its hybridization with the parapatric sibling R. montagui. Mar. Ecol. Prog. Ser. 554: 99-113.

General Fisheries Commission for the Mediterranean (GFCM). 2014. Report of the Workshop on elasmobranch conservation in the Mediterranean and Black Sea. Scientific Advisory Committee (SAC) of the General Fisheries Commission for the Mediterranean (GFCM). Sète, France, 10-12 December 2014. 26 pp.

Gouraguine A., Hidalgo M., Moranta J., et al. 2011. Elasmobranch spatial segregation in the western. Mediterr. Sci. Mar. 75: 653-664.

Gu C., Wahba G. 1991. Minimizing GCV/GML Scores with Multiple Smoothing Parameters via the Newton Method. SIAM J. Sci. Stat. Comput. 12: 383-398.

Guijarro B., Quetglas A., Moranta J., et al. 2012. Inter- and intra-annual trends and status indicators of nektobenthic elasmobranchs off the Balearic Islands (northwestern Mediterranean). Sci. Mar. 76: 87-96.

Hair J.F., Black W.C., Babin B.J., et al. 2010. Multivariate Data Analysis. Vectors. Pearson Ed. Ltd, Edinburgh.

Heithaus M.R., Wirsing A.J., Dill L.M. 2012. The ecological importance of intact top-predator populations: a synthesis of 15 years of research in a seagrass ecosystem. Mar. Freshw. Res. 63: 1039-1050.

Iglésias S.P., Toulhout L., Sellos D.P. 2010. Taxonomic confusion and market mislabelling of threatened skates: Important consequences for their conservation status. Aquat. Conserv. 20: 319-333.

Juki?-Peladi? S., Vrgo? N., Krstulovi?-?ifner S., et al. 2001. Long-term changes in demersal resources of the Adriatic Sea. Comparison between trawl surveys carried out in 1948 and 1998. Fish. Res. 53: 95-104.

Kavadas S., Maina I., Damalas D., et al. 2015. Multi-Criteria Decision Analysis as a tool to extract fishing footprints and estimate fishing pressure: application to small scale coastal fisheries and implications for management in the context of the Maritime Spatial Planning Directive. Mediterr. Mar. Sci. 16: 294-304.

Kriwet J., Witzmann F., Klug S., et al. 2008. First direct evidence of a vertebrate three-level trophic chain in the fossil record. Proc. R. Soc. Lond, B. Biol. Sci. 275: 181-186. PMid:17971323 PMCid:PMC2596183

Lack M., Sant G. 2009. Trends in global shark catch and recent developments in management. TRAFFIC International. Cambridge, 33 pp.

Ligas A., Osio G.C., Sartor P., et al. 2013. Long-term trajectory of some elasmobranch species off the Tuscany coasts (NW Mediterranean) from 50 years of catch data. Sci. Mar. 77: 119-127.

Maravelias C.D., Tserpes G., Pantazi M., et al. 2012. Habitat Selection and Temporal Abundance Fluctuations of Demersal Cartilaginous Species in the Aegean Sea (Eastern Mediterranean). PLoS ONE 7: e35474. PMid:22536389 PMCid:PMC3335001

Marongiu M.F., Porcu C., Bellodi A., et al. 2017. Temporal dynamics of demersal chondrichthyan species in the central western Mediterranean Sea: The case study in Sardinia Island. Fish. Res. 193: 81-94.

Massutí E., Moranta J. 2003. Demersal assemblages and depth distribution of elasmobranchs from the continental shelf and slope off the Balearic Islands (western Mediterranean). ICES J. Mar. Sci. 60: 753-766.

Megalofonou P., Damalas D., Yannopoulos C. 2005. Composition and abundance of pelagic shark by-catch in the eastern Mediterranean Sea. Cybium 29: 135-140.

Melendez M.J., Baez J.C., Serna-Quintero J.M., et al. 2017. Historical and ecological drivers of the spatial pattern of Chondrichthyes species richness in the Mediterranean Sea. PLoS ONE 12: e0175699. PMid:28406963 PMCid:PMC5391105

Moranta J., Massutí E., Stefanescu C., et al. 2008a. Short-term temporal variability in fish community structure at two western Mediterranean slope locations. Deep-Sea Res. Pt. I. 55: 866-880.

Moranta J., Quetglas A., Massutí E., et al. 2008b. Spatio-temporal variations in deep-sea demersal communities off the Balearic Islands (western Mediterranean). J. Mar. Syst. 71: 346-366.

Nieto A., Ralph G.M., Comeros-Raynal M.T., et al. 2015. European Red List of marine fishes. Publ. Off. Eur. Union, Luxembourg, 84 pp.

Notarbartolo Di Sciara G. 2014. Sperm whales, Physeter macrocephalus, in the Mediterranean Sea: a summary of status, threats, and conservation recommendations. Aquat. Conserv. Mar. Freshw. Ecosyst. 24: 4-10.

Osio G.C., Orio A., Millar C.P. 2015. Assessing the vulnerability of Mediterranean demersal stocks and predicting exploitation status of un-assessed stocks. Fish. Res. 171: 110-121.

Ordines F., Massutí E., Moranta J. et al. 2011. Balearic Islands vs Algeria: two nearby western Mediterranean elasmobranch assemblages with different oceanographic scenarios and fishing histories. Sci. Mar. 75: 707-717.

Peristeraki P., Kypraios N., Lazarakis G., et al. 2008. By-catches and discards of the Greek swordfish fishery. Col. Vol. Sci. Pap. ICCAT 62: 1070-1073.

Polidoro B.A, Livingstone S.R., Carpenter K.E., et al. 2008. Status of the world's marine species. In: Vié J.C., Hilton-Taylor C., Stuart S.N. (eds). Wildlife in a changing world: an analysis of the 2008 IUCN Red List of threatened species. Int. Union Conserv. Nat., Gland, Switzerland, pp. 55-65.

Polidoro B.A., Brooks T., Carpenter K.E., et al. 2012. Patterns of extinction risk and threat for marine vertebrates and habitat-forming species in the Tropical Eastern Pacific. Mar. Ecol. Progr. Ser. 448: 93-104.

QGIS Development Team. 2017. Geographic Information System. Open Source Geospatial Foundation Project.

R Development Core Team. 2018. R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria.

Ramírez-Amaro S., Ordines F., Terrasa B., et al. 2015. Demersal chondrichthyans in the western Mediterranean: assemblages and biological parameters of their main species. Mar. Freshw. Res. 67: 636-652.

Relini G., Biagi F., Serena F., et al. 2000. I Selaci pescati con lo strascico nei mari italiani. Biol. Mar. Mediterr. 7: 347- 384.

Rodríguez-Cabello C., González-Pola C., Rodríguez A., et al. 2018. Insights about depth distribution, occurrence and swimming behavior of Hexanchus griseus in the Cantabrian Sea (NE Atlantic). Reg. Stud. Mar. Sci. 23: 60-72.

Russo T., Bitetto I., Carbonara P., et al. 2017. A holistic approach to fishery management: evidence and insights from a Central Mediterranean Case Study (Western Ionian Sea). Front. Mar. Sci. 4: 193.

Sbrana M., Mannini A., Sartor P. et al. 2013. D11 - Report geo- Referred information on the spatial and temporal distribution of fishing effort/grounds for the case studies. DG Mare MAREA Mediterranean Halieutic Resources Evaluation and Advice Specific Contract no 7 --STOCKMED: "Stock units: Identification of distinct biological units (stock units) for different fish and shellfish species and among different GFCM-GSAs. 157 pp.

Serena F., Papacostantinou C., Relini G., et al. 2009. Distribution and abundance of spiny dogfish in the Mediterranean sea based on the Mediterranean International Trawl Surveys Program. In: Gallucci V.F., McFarlane G.A., Bargmann G.C. (eds). Biology and management of dogfish sharks. Am. Fish. Soc., Bethesda, Maryland, pp. 139-149.

Sion L., Bozzano A., D'Onghia G., et al. 2004. Chondrichthyes species in deep waters of the Mediterranean Sea. Sci. Mar. 68: 153-162.

Stevens J.D., Bonfil R., Dulvy N., et al. 2000. The effects of fishing on sharks, rays, and chimaeras (chondrichthyans), and the implications for marine ecosystems. ICES J. Mar. Sci. 57: 476-494.

Stevens J.D., Walker T.I., Cook S.F., et al. 2005. Threats Faced by Chondrichthyan Fish. In: Fowler S.L., Cavanagh R., et al. (eds). Sharks, Rays and Chimaeras: The Status of the Chondrichthyan Fishes. IUCN/SSC Shark Specialist Group, Gland, Switzerland and Cambridge, UK, pp. 48-57.

Tsagarakis K., Mytilineou C., Haralabous J., et al. 2013. Mesoscale spatio-temporal dynamics of demersal assemblages of the Eastern Ionian Sea in relationship with natural and fisheries factors. Aquat. Living Resour. 26: 381-397.

Tserpes G., Tatamanidis G., Peristeraki P. 2006. Oilfish and shark by-catches of the Greek swordfish fishery in the E. Mediterranean; a preliminary analysis applied to "presence-absence" data. Col. Vol. Sci. Pap. ICCAT 59: 987-991.

Tserpes G., Maravelias C.D., Pantazi M., et al. 2013. Distribution of relatively rare demersal elasmobranchs in the eastern Mediterranean. Estuar. Coast. Shelf. Sci. 117: 48-53.

Vasilakopoulos P., Maravelias C.D., Tserpes G. 2014. The Alarming Decline of Mediterranean Fish Stocks. Curr. Biol. 24: 1643-1648. PMid:25017210

Wood S.N. 2006. Generalized additive models: an introduction with R. Chapman and Hall/CRC Press. Boca Raton, Florida. 392 pp.

Worm B., Davis B., Kettemer L., et al. 2013. Global catches, exploitation rates, and rebuilding options for sharks. Mar. Policy 40: 194-204.

Zuur A.F., Ieno E.N., Elphick C.S. 2010. A protocol for data exploration to avoid common statistical problems. Methods Ecol. Evol. 1: 3-14.



How to Cite

Follesa MC, Marongiu MF, Zupa W, Bellodi A, Cau A, Cannas R, Colloca F, Djurovic M, Isajlovic I, Jadaud A, Manfredi C, Mulas A, Peristeraki P, Porcu C, Ramirez-Amaro S, Salmerón Jiménez F, Serena F, Sion L, Thasitis I, Cau A, Carbonara P. Spatial variability of Chondrichthyes in the northern Mediterranean. Sci. mar. [Internet]. 2019Dec.30 [cited 2024Apr.20];83(S1):81-100. Available from:




Most read articles by the same author(s)

1 2 3 4 5 > >>