Evaluación de diferentes estrategias de gestión para el marrajo dientuso (Isurus oxyrinchus) y la tintorera (Prionace glauca) en las pesquerías de palangre de superficie españolas en el Atlántico

Shortfin-mako (Isurus oxyrinchus) and blue shark (Prionace glauca) are considered a relevant by-catch in the Spanish longline fisheries in the Atlantic Ocean. Recent concern has been raised after the last shortfin-mako evaluation for the northern Atlantic in 2017. It stated the population being overfished and suffering from overfishing. Even though blue shark capture levels appear to be within sustainable fishing limits it is subject to high extraction rates in the Atlantic. Few data and uncertainty in assessment results suggest that further management strategies could be taken into account for both species. The aim of this study is to evaluate different fisheries management strategies for shortfin-mako and blue shark in the Atlantic from the stackeholders perspective. Information was collected through personal interviews with fishermen and surveys sent out to scientists and NGOs. Local Ecological Knowledge (LEK) was considered to be useful as fishermen possess a unique knowledge based on their continued interaction with the species and environment. Interviews allowed to understand the fishermen‘s interpretation on variations of stock abundance, distribution patterns, size of capture and seasonal fluctuations for both species. SWOT-analysis was used to study the different factors to be taken into account for various management measures. Main management strategies proposed by the sector were time-area closure, especially for blue shark juveniles during the summer months in the Sole Bank, minimum capture size and a quota system. Scientists and NGOs further proposed to investigate the effect of gear depth and hook shape as a management tool. Lastly, observations of fishermen about ecological features of both species could be used as a point of reference for future scientific studies.