Abundance And Size 149 



there was little thermal stratification (Fig. 3). On several occasions the water col- 

 umn was colder at the surface when strong, cold winds were present. On the 

 other hand, salinity was often positively stratified, as much as 6 ppt less saline at 

 the surface. At Oregon Inlet during early February, when there was a 5 ppt dif- 

 ference between the surface and bottom, the surface was 1C colder than the bot- 

 tom. At this time, the current direction at the surface was ebbing. 



Table 1. Average weekly densities (number per 100 m 3 ± 1 standard error) at 

 Oregon Inlet and Ocracoke Inlet (0.8-m 2 net, this study) compared with Beaufort 

 Inlet (2-m 2 net, S. Warlen, NMFS, Beaufort Laboratory, personal communica- 

 tion) during the October 1994 - April 1995 immigration season (n=27 weeks). 

 Values connected with a dashed line are not significantly different (Wilcoxon 

 rank sum test, a =0.05). 



Species Oregon Inlet Ocracoke Inlet Beaufort Inlet 



Brevoortia tyrannus 43.2 (± 4.1) 43.5 (± 4.9) 22.9 (± 8.4) 



Lagodon rhomboides 0.6 (±0.1) 1.7 (±0.3) 12.4 (± 3.9) 



Leiostomus xanthurus 4.4 (±1.0) 21.1 (" 4.8) 4.8("18.7) 



Micropogonias undulatus 155.5(± 27.1) 26.9 (± 3.9) 25.7 (± 6.1) 



Paralichthys dentatus 1.0 (± 0.2) 0.3 (± 0.1) 0.3 (± 0.2) 



Paralichthys lethostigma 0.1 (± 0.1) 0.5 (± 0.1) 0.8 (± 0.3) 



ABUNDANCE 



Unlike the other five selected species, Atlantic menhaden were not sig- 

 nificantly different in average weekly density at any inlet, although fewer 

 appeared to be caught at Beaufort Inlet during the year (Table 1). Spot were less 

 abundant at Oregon Inlet than the other inlets, but Atlantic croaker were most 

 abundant at Oregon Inlet. Pinfish {Lagodon rhomboides) and southern flounder 

 (P. lethostigma) were different in density among all inlets. Spot, pinfish, and 

 southern flounder increased in density towards the south, whereas Atlantic 

 croaker and summer flounder decreased, which is the expected pattern based on 

 the known distribution of these species (Fahay 1983). North Carolina is the cen- 

 ter of the known spawning range of Atlantic menhaden (Freidland et al. 1996), 



