SEMINAR: OI Seminar Series - Xabier Irigoyen

Title: Anchovy collapse in the Bay of Biscay: to eat or not to eat

Abstract: Anchovy (Engraulis enchrasicolus) is one of the main resources of the Basquepurse seiner fleet in the Bay of Biscay, as well as a cultural item for thesociety. A succession of recruitment failures starting in 2002 conducted to the collapse of the stock and the closure of the fishery in 2005. A major research effort has been conducted to understand the causes of the recruitment failures addressing some of the main hypothesis about factors controlling small pelagic fish recruitment such as enrichment and retention in areas with high food concentration. In this presentation I will show results from the Ecoanchoa project about climate impact on recruitment, relations between food abundance and recruitment, egg larvae and juveniles distribution, growth and trajectories (otolith microchemistry), population structure (genetics) and trophic relations (modelling and diet analysis). Contrary to expectations the results indicate that recruitment increases when climatic conditions favour transport outside the shelf during the larval stages with return to the shelf as juveniles. Modelling and diet analysis suggest that such and excursion off the shelf may result in a reduction of intraguild predation pressure on the early stages.