The position of meroplanktonic larvae in the water column with depth-dependent current velocities determines horizontal transport trajectories. For those larvae occurring in inner shelf waters, little is known about how combined diel and tidally-synchronized vertical migration patterns shift ontogenetically.

No abstract

following spring, the three cohorts had fused into a single young-of-the year cohort. Veligers were present across all depth layers in the water column down to 20 m, with a quarter being present within the surface 1 m. Drift cards were driven ashore, with cumulative retrieval rates of 50 and 70 % 3 and 9 d after release, respectively, suggesting that hydrodynamics allowed good retention of larvae in the water surface. Using an exponentially decreasing function describing competent larval numbers in a 2 to 9-d period after fertilization in the laboratory, the degree of self-recruitment in the population was assessed under the assumption of complete retention and no mortality of larvae due to predation. The results suggested the presence of some allochthonous subsidy.