Fishes of Cape Fear Estuary 19 



southwest winds during nine months of the year. 



The estuary is 0.3 km wide at Wilmington, widens to 2.1 km at 

 Snows Cut and 2.0 km at its mouth. River discharge, which once passed 

 through Corn Cake Inlet, has been diverted via a dredged channel to 

 enter the sea between Baldhead Island and Caswell Beach, just east of 

 Southport (Carpenter and Yonts 1979). The present dredged river chan- 

 nel varies from 7.6 to 13.6 m deep between the estuary mouth and Wil- 

 mington. North and west of Wilmington, the Northeast Cape Fear and 

 Cape Fear rivers shoal to 3.7 and 3.6 m, respectively. The main ship 

 channel has a mud-clay substrate throughout most of its length, with 

 silting occurring north of Wilmington. Shoals exist on either side of the 

 ship channel. From Wilmington south to Buoy 42 the narrow east and 

 west shoals, on either side of the channel, are composed of sandy-mud. 

 South of Snows Cut eastern shoals are typically sandy while mud domi- 

 nates western shoals. Extensive mud flats are present in the vicinity of 

 the mouth of the river at Caswell Beach. A Pleistocene sandstone and 

 the porous Castle Hayne formation creates a series of rock ledges that 

 pass from southwest to northeast across the river at Buoy 18 and pro- 

 duce a sill on the east side of the river near the buoy. 



Our study area included all major tidal tributaries and the North- 

 east Cape Fear River from 36 km north of Wilmington to near Buoy 46; 

 the main Cape Fear River from Lock 1 (63 km northwest of Wilming- 

 ton); and the main river south of Wilmington (including the man-made 

 Snows Cut channel), 24 km south of Wilmington on the east side of the 

 river to its junction with the Atlantic Ocean (Fig. 1). The south- 

 western boundary of the study area was Dutchman's Creek, 3.6 km west 

 of the Intracoastal Waterway at Southport. The seaward boundary was 

 the Atlantic Ocean and encompassed an area from the eastern tip of 

 Baldhead (Smith) Island on the east, westward to Long Beach, North 

 Carolina, and for 8 km offshore to depths of 12 m. 



MATERIALS AND METHODS 



Schwartz et al. (1979, 1979) employed 91.4 m gill nets to sample 

 pelagic species during January through November 1973-1980. Otter 

 trawls of 7.6 and 12.2 m were used to sample all other fishes at shoal, 

 channel, power plant intake canal, and ocean stations during the same 

 period. Weinstein et al. (1980b) employed rotenone and beach seines at 

 tidal creek stations throughout the saline portion of the Cape Fear. 

 Details of sampling methodology were cited in Weinstein et al. (1979). 

 One excellent and efficient continuous sampling device was the traveling 

 screens located at the head of an intake canal at the power plant, which 

 were cleaned several times daily. Three species were obtained by North 

 Carolina State University (Copeland et al. 1979) and Carolina Power 



