Capture Efficiency of Artificial Lures in Baited Lines for Mayan Octopus, Octopus maya, Fishery in Campeche, Mexico

The Mayan octopus, Octopus maya, fishery from the Campeche Bank is the largest octopus fishery in the Americas and one of the largest worldwide. This fishery uses a large quantity of crabs, Brachyura, as bait, and these crustacean populations are heavily impacted. To investigate alternative lures we examined the efficacy of various artificial lures ranging from plastic crabs to jigs baited with fish during the 2012 and 2013 seasons. Artificial PVC “crab” lures showed the best yields. However, their performance was less effective than natural crab in all cases. A simple simulation showed that using these lures, harvests would decrease by 42–44% compared to using natural crab. We suggest the use of PVC crab combined with an organic compound that releases an attractive scent for octopus in further experiments. Requirements for Marine Stewardship Council certification to minimize impacts on ecosystems are a serious constraint to certifying bait fisheries (Goyert et al., 2010). Introduction of exotic baits also can carry undesirable ecological and social impacts (Gillett, 2011). Additionally, some baits such as crabs, Brachyura, may themselves be taken with baited devices (Dellinger et al., 2016), and this may in turn impact or harm other fisheries. These shortcomings are also documented in octopus fisheries using baits. For example, Japanese ghost crabs, Macrophthalmus japonicus, used as bait in traps for Octopus minor in the Republic of Korea must be imported from China (Kim et al., 2015). The Mayan octopus, Octopus maya, fishery on Mexico’s Campeche Bank with annual landings over 15,000 t is the largest octopus fishery in the Americas and one of the largest worldwide (FAO, 2018). This fishery employs lines baited with various crab species such as Florida stone crab, Menippe mercenaria; longnose spider crab, Libinia dubia; and blue crab, Callinectes spp., among others. This fishing method is considered to be sustainable regarding the octopus, as no spawning females, which stop feeding, are taken (Markaida et al., 2017). However, this fishery consumes a vast quantity of crabs, whose populations are negatively impacted, a fact noticed long ago (Solís-Ramírez, 1998; SolísRamírez et al., 1999; Carmona-Osalde and Rodríguez-Serna, 2012). Stone crab is the main bait used in the octopus fishery in Lerma and Campeche, despite its express prohibition by both stone crab and octopus regulations (DOF, 2016a,b). A local commercial fishery harvests 16 annual tons of crab claws using traps. Additionally, it is taken illegally by skin divers. Our limited data from six octopus fishermen during the 2012 and 2013 seasons estimated that each fisherman used 145 dozen (174 kg) declawed stone crabs per season (110 days) as bait. A rough estimate from a conservative figure of 700 fishermen in Lerma and Campeche would use 122 t of declawed crabs per season. This is a far larger amount than the official catch of stone crab as suggested by claw landings. If the octopus fishery employs 10,000 fishermen in all the Yucatan peninsula, bait use would be 900 t of crabs per year, which represents half of all combined crab species (mainly blue crabs) landings in the Yucatan peninsula in those years (CONAPESCA, 2017). Crabs are a particularly expensive bait that may comprise half of the total daily costs involved in the fishery (see below). Use of crabs is a current concern in the management plan of this fishery (DOF, 2014) and it might constrain its desirable future certification. Several discrete experiments have been worked out to try to substitute plastic crabs for natural crabs in this fishery. Clay pots “nummarellas” and collapsible traps have also been tested, but with no further follow up (SolísRamírez, 1998; Solís-Ramírez et al., 1999). Most experimental octopus fishing worldwide has been done using baited traps or artificial habitats (Barry et al., 2010; Rudershausen, 2013). To our knowledge, the only bait substitution experiment with fishing lines was performed in the giant Pacific octopus,