Spatial variability of Chondrichthyes in the northern Mediterranean

Scientia Marina

Pierluigi Carbonara¹  Walter Zupa¹  Letizia Sion²  Ioannis Thasitis³  Antonello Mulas⁴  Maria C. Follesa⁴  Alessandro Cau⁴  Cristina Porcu⁴  Rita Cannas⁴  Martina F. Marongiu⁴  Angelo Cau⁴  Andrea Bellodi⁴  Panagiota Peristeraki⁵  Mirko Djurovic⁶  Igor Isajlovic⁷  Sergio Ramirez-Amaro⁸  Francisca Salmerón Jiménez⁹  Chiara Manfredi^1,10  Angélique Jadaud^1,11  Fabrizio Serena^1,12  Francesco Colloca^1,13 

[1] COISPA Tecnologia & Ricerca;Department of Biology, University of Bari;Department of Fisheries and Marine Research;Department of Life and Environmental Science, University of Cagliari;Hellenic Center for Marine Research, Institute of Marine Biological Resources and Inland Waters - University of Crete, Biology Department;Institute of Marine Biology, University of Montenegro;Institute of Oceanography and Fisheries;Instituto Español de Oceanografía, Centro Oceanográfico de Baleares;Instituto Español de Oceanografía, Centro Oceanográfico de Málaga;Laboratorio di Biologia Marina e Pesca di Fano, Università di Bologna;MARBEC-IFREMER, IRD, Université Montpellier 2, CNRS;National Research Council, Institute for Coastal Marine Environment;Stazione Zoologica A. Dohrn;

关键词: fish;    chondrichthyes;    bottom trawl surveys;    distribution;    abundance;    mediterranean;   

DOI  :  10.3989/scimar.04998.23A

来源: DOAJ

【 摘 要 】

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.

【 授权许可】

Unknown