Modelling the transport of larval sandeels on the north-west European shelf

This study considers the interannual variability in the advection of sandee l (Ammodytes marinus) larvae on the north-west European shelf We use recent ly collated data on spawning location, age of larvae and the time of hatchi ng (between 1955 and 1993) as input to a particle-tracking model. Utilizing hourly currents from a 39 year run of a two-dimensional sea circulation mo del, cohorts of sandeel larvae were represented as a distribution of partic les in space and time, and particle drift was calculated for the larval lif e stage. The final distributions of particles were compared with actual dis tributions of 0-group sandeels in the North Sea, as determined from surveys conducted at around the end of the larval phase. Preliminary examination o f the data between 1973 and 1993 indicates that differences in predicted dr ift could explain some of the large interannual variability in 0-group dist ributions. This approach may help to improve our understanding of the frequ ent colonization events that are typical of this species.