Challenges of management strategy evaluation for small pelagic fish: the Bay of Biscay anchovy case study

Modelling of major uncertainties in population and fishing dynamics are fundamental for reliable Management Strategy Evaluation. Present work describes the modelling work carried out for the bio-economic impact assessment of alternative Harvest Control Rules (HCRs) for developing a management plan for Bay of Biscay anchovy, using FLBEIA software, and how the modelling work was adapted as new biological information and data sources were available. The underlying general HCR consists of exploiting a proportion of the estimated Spawning Stock Biomass and is operative for two alternative management calendars: July-June or January-December. The final shape of the rule is determined by the harvest rate, the biomass trigger points and the TAC thresholds. The performance of the HCRs is evaluated according to the biological and economic risks, probability of fishery closure, expected average catches and their standard deviation. Robustness of these rules, given alternative recruitment models and quota shares among fleets, is also tested. In general, the inclusion of an available recruitment index allows moving the management calendar from July-June to January-December and leads to higher (~15%) and more stable average catches, while reducing biological risks and the probability of fishery closure (by ~25%). The presence of minimum and maximum TAC levels allowed to improve fishery performance. Recruitment was the uncertainty of major relevance in determining the relative performance of the rules, while there was little effect on biological risk of different quota shares among countries. The simulation results were the cornerstone for the selection of the adopted HCRs by stakeholders and managers.

SANCHEZ Sonia;  IBAIBARRIAGA Leire;  URIARTE Andres;  PRELLEZO Raul;  ANDRÉS Marga;  ABAUNZA Pablo;  GAMITO JARDIM José Ernesto;  LEHUTA Sigrid;  PAWLOWSKI Lionel;  ROEL Beatrix; 

2018-12-21

INTER-RESEARCH

JRC109390

0171-8630 (online),   

https://www.int-res.com/abstracts/meps/spf/av9/,    https://publications.jrc.ec.europa.eu/repository/handle/JRC109390,   

10.3354/meps12602 (online),