Could Biscay Bay Anchovy recruit through a spatial loophole

Abstract In the Bay of Biscay, anchovy juveniles are regularly observed off the shelf whereas spawning occurs over the shelf, mainly in the river plumes. This distribution of the juveniles can be interpreted as advective losses of the population recruiting over the shelf. However, recent research suggests an alternative interpretation based on the possibility of the population exploiting the off the shelf waters for recruitment through a loophole of lower predation. In this article, we test this second hypothesis through a review of the information available about different processes in the Bay of Biscay (anchovy distribution, size at age spatial differences, recruitment timing and spatial distribution and potential predators distribution). We also develop a model to explore recruitment success when predation risk is positively correlated with feeding opportunities. We conclude that the hypothesis of anchovy using off-shore (oceanic) waters as a spatial loophole for recruitment cannot be excluded.