Investigating of Slipping (Releasing of Unwanted Species) in the Aegean Sea Purse Seine Fıishery
Project no. 20581 · Status: Kapanmış · 2019
Summary
Although mostly jellyfish slipping (excluding) process applied particularly in the Sea of Marmara, there is no landing statistics or a scientific study regarding slipping procedure, slipped species and their amount in the Aegean Sea. In this thesis, the application of slipping process, slipping amount and most slipped species in the Aegean sea purse seine fishery were investigated. In addition, the characteristics, equipment and rigging of the purse seine vessel and nets, the fishing areas and landing components of the fishing were also investigated. The study findings were obtained from face-to-face questionnaires with purse seiner skippers in the Aegean ports between April 15, 2019 and September 1, 2019, at the time of the purse seine closed season. Percentages of the purse seiner in the Northern Aegean and Middle Aegean, applied slipping process, were determined as 100% and 89%, respectively of 56 purse seiner registered to the Aegean ports. On the other hand, South Aegean is the lowest percentage (23%). Among the most important reason of slipping applied by the seiner is small size fishes (below Minimum Landing Size) and storage deck capacity of the purse seiner with 46 percentage. This is followed by 18% of the fish being juvenile and bycatch species. Considering the application rates of the slipping process on the species, anchovy (Engraulis encrasicolus) takes the first place with 72.4%. It was determined that 2.550 tonnes of fish were slipped into the sea during the 2018 -2019 fishing season. The determined of slipped amount of fish in the thesis is very important in terms of providing data to the unaccounted mortality rates in stock assessments.