The traditional small-scale octopus trap fishery off the Galician coast (Northeastern Atlantic): Historical notes and current fishery dynamics

Abstract

Common octopus is a worldwide important cephalopod resource fished by both industrial and small-scale fleets which has gained market value in recent decades. In Galicia (NW Iberian Peninsula), common octopus (Octopus vulgaris sensu stricto) has been exploited since ancient times in intertidal and subtidal areas using multiple methods and fishing gears. A vast artisanal fleet using traps has been exclusively dedicated to catching this species since the 1970s. However, a comprehensive description of current fishery dynamics and production is lacking. A total of 1255 vessels had permission to deploy traps in 2016, though effective license usage was considerably lower and has steadily decreased since 2004. The fleet, in recent years, was largely composed of vessels of ∼4.5 t of average gross tonnage (GRT) although the proportion of vessels per GRT segment has changed showing a decrease in vessels of lower and greater segments of GRT, whereas intermediate and more polyvalent segments, mainly between 2.5 and 4.99 GRT, increased notably. On average, the fleet deploys ∼66 traps per haul usually set on a given day and hauled the next one yielding from 0.13 kg trap−1 in the south to 0.25 kg trap−1 in the north. Fishing operations (i.e. number of traps deployed, soak time, fishing depth, and trip length) varied seasonally and along the coast and depended on vessels’ size. Similarly, fishing strategies (i.e. alternation of traps with other gears) also differed along the coastline and during the year. Fishing effort estimated as the number of deployed traps has decreased slightly since mid 2000s and so has expected catches though more pronounced in the northern coast as compared to the south. Furthermore, estimated catches were notably higher than official reported values regardless of the zone. This article provides new insights into the current fishery dynamics of an important small-scale fishery that should be useful for the development and implementation of new assessment and management plans for common octopus in the north-west coast of Spain