Valutazione delle catture accidentali di specie protette nel traino pelagico BYCATCH 2014-2015

Bycatch is one of the main sources of anthropogenic mortality of species of conservation concern worldwide. Between November 2014 and February 2016, CNR-ISMAR of Ancona coordinated a monitoring programme of cetacean bycatch in Italian pelagic trawlers (BYCATCH 2014-2015 - extension 2016), funded in compliance with the Regulation (EC) No.812/2004. Other two partners were involved in the monitoring, data collection and analyses: CoNISMa and ISPRA. This report gives a summary of the overall monitoring activities carried out by all partners with particular emphasis on the investigations performed by CNR-ISMAR research team. Overall, 12 independent observers monitored 464 fishing trips for a total of 1797 hauls. This comprised bycatch records of a number of species of conservation concern. Specifically, only one event of accidental capture of bottlenose dolphins Tursiops truncatus was recorded, while 587 individuals have been sighted during fishing operations. Furthermore, 23 loggerhead turtles Caretta caretta, 209 twaite shad Alosa fallax and 2 fan mussel Pinna nobilis captures were also reported. However, elasmobranchs represented the majority of the bycatch. Indeed, smooth hound Mustelus mustelus (101), spiny dogfish Squalus acanthias (90) and common eagle ray Myliobatis Aquila (85) were the most commonly caught species over the year. A fine-scale genetic structure of bottlenose dolphin was recorded within the Adriatic Sea. Sea trials with sorting grid (FLEXGRID) revealed poor fishing performance in terms of hydrodynamics and catch. Thus, this device might not be suitable for pelagic trawlers. Finally, the interaction between cetaceans and pelagic trawlers should be carefully considered in the next monitoring programme.