How using live bait affects longline bycatch in the artisanal fishing fleet of Costa Rica : The dilemma between live and dead bait

Abstract: Long-lining is a frequently used method in marine fisheries. Similarly to trawling and nets, also long-lining is associated with bycatch which may have negative impacts on the ecosystems. However, different methods of long-lining may vary in the amount and ratio of bycatch but methods have rarely been compared directly. This study investigates whether the fishing method of floated demersal longlining baited with live Pacific Anchoveta (Cetengraulis mysticetus) has a lower bycatch ratio or bycatch amount than using demersal long lines baited with filet pieces of dead fish. The study was carried out in collaboration with artisanal small-scale fishermen in the Paquera area of the Gulf of Nicoya in Costa Rica. Six efforts were made in February of 2023, and were then compared to dead bait data from the same area from 2015 and 2016 collected by Universidad Nacional de Costa Rica. This comparison showed no significant difference between the two methods in bycatch ratio but showed that live bait longlining captures significantly more total fish and bycatch per catch per unit effort (CPUE). There are also ethical issues and issues with bait fish acquirement that points against live bait fishing. However, there are certain arguments in support of the method, such as broadening the exploitation strain across more species and not hindering financially struggling artisanal fishermen further.