A bio-physical model of sardine larvae off the Atlantic Portuguese coast, incorporating a three-dimensional circulation model, was used to estimate changing biomass during winter upwelling and downwelling events. The growth rate of larvae was modelled as a function of age, temperature, and prey concentration and the mortality rate as a function of age and temperature. Numerical results indicate that upwelling events during the spawning season may have a negative impact on larval survival. Total larval biomass seems to be mainly controlled by larval prey relative to temperature. This preliminary study does not account for the dynamics of the food chain and therefore the intense biological activity associated with an upwelling event, as well as the influence of river plumes in retention mechanisms.

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