IRD (France), 24. Hopkins Marine Station of Stanford University (USA), 25. National Institute of Oceanography and Fisheries (NIOF)(Egypt)

Abstract

The Mediterranean Large Elasmobranchs Monitoring (MEDLEM) database contains more than 2000 records (n>3000 individuals) of large elasmobranchs species from 20 different countries around the Mediterranean Sea caught or observed from 1666 to 2014. The main species represented in the archive are devil rays (736 individuals), basking sharks (682 individuals), blue sharks (525 individuals) and white shark (281 individuals). In the last decades other species such as shortfin mako (137 individuals), spiny butterfly ray (136) and thresher shark (125 individuals) are reported with an increasing frequency, possibly
due to a higher public awareness on the conservation status of sharks, and consequent development of monitoring programs. Unfortunately MEDLEM does not cover with equal sampling effort all Mediterranean sectors. Scientific monitoring in the south-eastern Mediterranean is generally lower than in the northern sectors and therefore the absence of some species from these regions (for example Rhinobatos sp. or Rhinoptera marginata) in the database does not imply their actual absence from the area. Morphometric measurements are often lacking but, at least for the main species , some analyses can be performed. For six species it was possible to draw a length
frequency distribution and a preliminary length-weight relationships for the great
white and basking sharks.Also some consideration about geographical distribution of the
main species can be done tanks to the data recorded in the MEDLEM database.It is important to create an international network among the ongoing monitoring
programs, such as the European Union program Data Collection Framework, SharkPulse (http://baseline.stanford.edu/) or the CIESM forum (http://www.ciesm.org/forums/index.php?post/Sharks).The high frequency of occurrence of M. mobular (736 specimens) reflects a recent (March 2013) evidence of massive catches of this specie off the Gaza Strip (Levantine Sea), where in a single episode, more than 500 rays were captured with a local type of purse seine, called “shinshula Most of the records are bycatch of set nets, longlines and purse-seine mainly due to the exceptional event in Gaza coasts. Others fishing methods (3%) are rifle-harpoon, anchovy mid-water
trawl, shrimp net and pole line.