Pelagic stingrays (Pteroplatytrygon violacea) are a common bycatch species in the Mediterranean pelagic longline swordfish fishery. Experimental trials took place in the central Mediterranean Sea from 2005 to 2007 to investigate the importance of bait size, presence and type of light attractors, and hook size and shape on pelagic stingrays. Bait size and light attractants did not have a significant effect on stingray catch rate. Larger J-hooks reduced the stingray capture rate. 16/0 circle hooks had a significantly lower number of stingrays captured than J-hooks, up to 80%
The biting behaviour of the loggerhead sea turtle, Caretta caretta, a high bycatch species by longling fishing gear, was studied on 30 wild specimens held temporarily at rescue centers. Chemicals from squid baits elicited significantly more biting behaviour than those from mackerel baits.
The proven effectiveness of a bycatch reduction technology (BRT) does not guarantee its adoption by fishermen. This case study evaluated the willingness of Sicilian longline fishermen to use relatively large circle hooks (16/0) as a BRT for loggerhead sea turtles (Caretta caretta). Fishermen tested circle hooks with their fishing vessels and their own commercial fishing gear, and their opinnions before and after trials at sea were recorded.