Abstract

Early models and evidence from genetics suggested that long distance dispersal of larvae is likely a common event leading to considerable populaúon connectivity among distant populations. However, recent evidence strongly suggests that local retention is more the role, and that long distance transport is likely insufficient to sustain marine populations over demographic time scales. We build on earlier model results to examine the probability of larval dispersal to down stream islands within different regions of the Caribbean at varying distances from source populations. Through repeated runs of an ocean circulation model (MICOM), coupled with a random flight model estimating larval sub-grid turbulent moúon, we estimate the likelihood of particular circulation events transporting large numbers of larvae to within 9km radii of downstream populations, as well as account for total accumulations of larvae over each year. Further, we incorporate realistic larval bebavior and mortality estimates and production variability into our models. Our results are consistent with the hypothesis that marine populations must rely on mechanisms eohancing self-recruitment rather than depend on distant 'source' populations.

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