Occurrences of large sharks in the open waters of the southeastern Mediterranean Sea

Abstract

Analysing large pelagic fisheries data from the open waters of the southeastern Mediterranean Sea during 1998 to 2005, we identified no more than 10 species of large sharks, although most updated literature cites more than twice this number in the region. We identified a statistically significant decline in species richness, with the probability of shark occurrence reducing to its lowest level in the most recent years. Blue shark was the predominant species, comprising approximately 70% of all large sharks encountered. A Milk shark was observed for the first time in the region. Based on their capture location, a series of maps depicting the spatial distribution of large sharks is provided. It seems as if currently the continuity of the presence of some species in the region may be questionable or that some species may have become too rare to be detected in the course of a conventional monitoring survey.

Keywords:

• shark
• oceanic
• Mediterranean
• longline
• chondrichthyan

Acknowledgements

We wish to thank all fishermen who assisted observers in data collection, both on-board fishing boats and at landing locations. This study was performed with the finance of the Commission of the European Communities (Projects No: 97/050 and 97/074 DG XIV/C1), as well as within Operational Programme Education by the ESF (European Social Fund) and National Resources. We appreciate the valuable comments of four reviewers, which significantly improved the quality of this manuscript.