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Fishery Bulletin 98(2) 



Table 4 



The occurrence of larvae (denoted by a "+" sign) from taxa that occur or spawn as adults in oceanic (> 185 m) and outer-shelf waters 

 (55-185 m) or that occur south of the study area (denoted by an asterisk) collected in middle-shelf waters (stations 3 and 4) during 

 two sampling periods of 24-h duration (denoted by day 1 and day 2). 



certainly influence the composition of ichthyoplank- 

 ton on the continental shelf. A major feature is the 

 intrusion of Gulf Stream waters onto the continental 

 shelf Additionally, during summer, southwest winds 

 result in the advection of shelf waters south of North 

 Carolina onto the North Carolina shelf (Pietrafesa, 

 1989). Intrusions of the Gulf Stream, along with the 

 advection of Georgian shelf water, appeared to be 

 evident in our study and could have influenced the 

 composition of ichthyoplankton on the shelf — particu- 

 ularly evident at the outer-shelf station (station 2) 

 where hydrographic conditions and size composition 

 of the two most abundant taxa changed within a 24-h 

 period. 



We identified 21 species of larvae on the middle 

 shelf from oceanic and outer-shelf waters and five 

 species which, as adults, occur in shelf waters south 

 of the study area (Table 4). The intrusion of these 

 larvae is a common event that occurs throughout all 

 seasons (Powell and Robbins, 1994; 1998; our study) 

 and appears to be related to water expelled from fron- 

 tal eddies created by Gulf Stream meanders that have 

 stranded on the continental shelf Nevertheless, we 

 were unable to determine the role of cross shelf trans- 

 port in the recruitment of subtropical and tropical reef 

 fishes and other taxa to waters off North Carolina. 



Our observations on larval fish distribution pat- 

 terns in relation to hydrography are derived from five 

 stations over a 48-h period. Longer-term studies, with 



extensive sampling, will be necessary to test assump- 

 tions made in our study, especially the transport of 

 larvae from the middle shelf to the outer shelf Sya- 

 cium papillosum a middle-shelf species that is abun- 

 dant from spring to early fall (Powell and Robbins 

 1994; 1998; our study) could serve as an indicator of 

 transport in long-term studies. Such studies could 

 test the hypothesis that circulation patterns during 

 late spring, summer, and early fall in shelf waters 

 off North Carolina retain larvae within the bays. The 

 major goal of future research should be to develop a 

 comprehensive model or scenario of larval transport 

 based on circulation patterns (e.g. Hare and Cowen, 

 1996). Such a model could provide a lucid framework 

 for testing larval transport hypotheses and be of heu- 

 ristic value as new problems are discovered. 



Acknowledgments 



We wish to express our appreciation to the crew of 

 the RV Cape Hatteras and those individuals who par- 

 ticipated in the cruise, especially Mike Greene. We 

 especially thank David Smith and Mark Leiby for lep- 

 tocephali identification, Curtis Lewis for figure prepa- 

 ration, and Dave Colby and Jim Waters for computer 

 assistance. Comments by Bill Hettler, Patti Marraro, 

 and Dave Peters along with those of two anonymous 

 reviewers greatly improved the manuscript. 



