NOTE Hare and Govoni: Larval fish transport and vertical distributions on the southeast US continental shelf 



733 



closer to the island. Peterson (1998) proposed that in 

 upwelling systems, copepods can affect retention on the 

 shelf through ontogenetic vertical migrations, whereby 

 younger stages inhabit the upper offshore-flowing wa- 

 ter and older stages inhabit the lower onshore-flowing 

 water (see also Peterson et al., 1979). Similar models 

 were developed by Pillar et al. (1989) and Barange and 

 Pillar (1992) for euphausiids in the Benguela upwelling 

 zone. Additionally, Batchelder et al. (2002) indicated 

 that copepods can be retained nearshore in upwell- 

 ing systems through diel vertical migrations between 

 offshore-flowing surface waters and onshore-flowing 

 bottom waters. From these studies and the results from 

 the present study, a general hypothesis emerges that in 

 many marine systems, fish larvae and zooplankton can 

 affect onshore transport by moving deeper in the water 

 column. Thus, similar to selective tidal stream trans- 

 port whereby larvae use predictable tidal flows to either 

 remain in estuaries or enter estuaries (Forward and 

 Tankersley, 2001), general features in circulation may 

 exist across physical oceanographic systems that allow 

 larvae to influence their cross-shelf transport through 

 basic changes in their vertical distribution. 



Acknowledgments 



We thank the participants of the South Atlantic 

 Bight Recruitment Experiment for their constructive 

 comments throughout this study. We also appreciate 

 the contribution of those who assisted in the field and 

 the officers and crews of the NOAA Ships Oregon II 

 and Chapman. Dave Colby, Frank Hernandez, Patti 

 Marraro, Allyn Powell, Larry Settle, Petra Stegmann, 

 and six anonymous reviewers commented on earlier 

 drafts of this manuscript. This study was completed 

 while the senior author held a National Research 

 Council Research Associateship at the NOAA Beaufort 

 Laboratory. 



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