Volume 54

The Role of Long Distance Dispersal versus Local Retention in Replenishing Marine Populations

Cowen, R.K.; Paris, C.B.;Olson, D.B.; Fortuna, J.L.
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Date: November, 2001

Pages: 129-137

Event: Gulf and Caribbean Research

City: Providenciales Turks & Caicos Islands

Country: Turks and Caicos Islands


Early models and evidence from genetics suggested that long distance dispersal of larvae is likely a common event leading to considerable population connectivity among distant populations. However, recent evidence strongly suggests that local retention is more the rule, and that long distance transport is likely insufficient to sustain marine populations over demographic timescales. We build on earlier model results to examine the probability of larval dispersal to downstream 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 motion, 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 behavior and mortality estimates and production variability into our models. Our results are consistent with the hypothesis that marine populations must rely on mechanisms enhancing self-recruitment rather than depend on distant ‘source’ populations.

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