Changes in fishing power and fishing strategies driven by new technologies: The case of tropical tuna purse seiners in the eastern Atlantic Ocean

Adaptive responses of tropical tuna purse-seiners under temporal regulations

“…Closed seasons do not necessarily reduce both nominal and effective effort, as much as anticipated (Branch et al 2006;Fulton et al 2011); in short term fishers will respond to environmental variability, market changes, and management regulations in order to increase, or at least to maintain their income and/or catch levels (Salas and Gaertner 2004;Branch et al 2006;Russo et al 2015), while in long term, fishers can invest in acquiring new vessels and/or new on-board technology (McIlgorm 2010;Torres-Irineo et al 2014). Our study provides an example of how fishers can respond to the implementation of seasonal regulations.…”

“…However, there are no records of major introduction of new on-board technology by Mexican purse-seiners after the closed season. Worldwide, the major improvements of on-board technology of tuna purseseiners have been observed for FAD-fishing since the early 1990s (Lopez et al 2014;Torres-Irineo et al 2014); hence the adaptations seem to be done at the operational level. Furthermore, as stated before, the introduction of technology is likely expected to affect directly the purse-seiners' activities at sea, i.e.…”

“…Acquisition of new technology and increase in vessel size, generally, have resulted on an increase in fleet capacity or efficiency with the associated impacts, such as access to new fishing grounds or catchability improvements (Rijnsdorp et al 2008;Eigaard et al 2014;Torres-Irineo et al 2014). This increase in fishing capacity affects many fisheries around the world resulting in overfishing and economic waste (Clark et al 2005;Beddington et al 2007;FAO 2008;Ye et al 2013).…”

Biodiversity and environmental characteristics of the bycatch assemblages from the tropical tuna purse seine fisheries in the eastern Atlantic Ocean

“…FAD sets have higher bycatch rates (241.5 t/1,000 t in FAD sets) (Amandè et al, ) and a larger number of species (Lezama‐Ochoa et al, ; Torres‐Irineo, Amandè, et al, ; Torres‐Irineo, Gaertner, Chassot, & Dreyfus‐León, ) than Free School sets (38.7 t/1,000 t in Free School sets). For example, Torres‐Irineo, Amandè, et al, , Torres‐Irineo, Gaertner, et al, reported 87 species in FAD sets and 61 species in Free School sets in the Atlantic Ocean. In the case of the Western Indian Ocean, Lezama‐Ochoa et al () reported 74 species in FAD sets and 56 in Free School sets.…”

“…The increase in FAD use from the 1990 s increased the purse seine catches of tropical tuna by nearly 60%, as well as the ecological problems associated with the bycatch managed by the International Commission for the Conservation of Atlantic Tunas (ICCAT) (Torres‐Irineo, Amandè, et al, ; Torres‐Irineo, Gaertner, et al, ).…”