Planktonic linkages among marine protected areas on the south Florida and southeast United States continental shelves

Abstract

One proposed benefit of marine protected areas (MPAs) is increased larval export, potentially increasing recruitment in unprotected areas. Because most marine species have planktonic larvae, information regarding planktonic transport is needed to evaluate the benefit of larval export. We used satellite-tracked drifters to define planktonic transport routes and rates from three MPAs along the south Florida and southeast United States (US) continental shelves. Drifter tracks indicated both long-distance transport and local retention. A probability model was developed based on drifter releases. The region was broken into zones; zone-specific residence times and movements between zones were defined from the drifter tracks. Transport out of the region in association with the Loop Current – Florida Current – Gulf Stream was the most frequently observed outcome, yet retention was high in the lower Florida Keys and on the Georgia shelf. From the model results, long-distance planktonic transport and local retention are the endpoints of a continuum rather than a dichotomy. Further, the outcome of planktonic transport is spatially heterogeneous with some regions exhibiting more retention and others exhibiting more export. The spatial aspects of planktonic transport described here should be considered in designing MPAs with fishery management objectives in the south Florida and southeast US shelf ecosystems.