68 MARINE FISHERIES OF NORTH CAROLINA 



little shoreline, but North Carolina, with multiple estuaries and the offshore 

 bar, has a better than average physiography in this respect. 



In many situations, chiefly in freshwater habitats, the yield has been 

 greatly increased by adding fertilizers. Yields of 400-600 lbs. /acre/year have 

 been obtained in the southeast by Swingle and Smith (1947) in ponds where 

 fish such as bluegills, which are low on the food chain, dominate the catch. 

 A spectacular increase was produced in certain marine Lochs in Scotland 

 where flat fish grew at several times their normal rate after their habitats were 

 fertilized (Gross, Raymont, Nutman and Gauld, 1946, and Raymont, 1947). 



Fertilization warrants considerable attention in North Carolina, as else- 

 where. It is not inconceivable that someday the mouths of the main rivers 

 might be used as feeders to add fertilizing nutrients to the sounds with the 

 offshore bar aiding by effectively impounding the derived benefits. There are, 

 however, in addition to practical economic limitations, at least two funda- 

 mental points that detract from the prospects of improved yields by this 

 means. Added nutrients provide their benefits by increasing basic production 

 where it has been limited because of deficiencies; yet the present discussion 

 has suggested that basic production has not been a limiting factor in the 

 State's fisheries yield. Also fertilizers may stimulate the growth of undesired, 

 instead of beneficial, plankton algae, not to mention the fact that some species 

 may react unfavorably when excessive numbers of microorganisms are pro- 

 duced (see, for example, Loosanoff and Engle, 1946). Conveniently, there 

 are in North Carolina many natural estuarine environments of varied sizes 

 and types that might be used for progressive experimentation with fertilizers. 



Summary Comments and Recommendations 



This study is an attempt to assimilate, analyze, and describe all pertinent 

 hydrographic information relative to North Carolina's marine fisheries as 

 accumulated up to the year 1947. Since the coverage is broad and descriptive, 

 this summary will of necessity be limited to selected items considered espe- 

 cially significant. 



An offshore bar runs the length of the North Carolina coast separating 

 inshore from oceanic waters. Where this bank, as it is called locally, projects 

 seaward as the Cape Hatteras prominence, it encloses broad sounds to the 

 west. To the south, where the bank lies closer to the mainland, the enclosed 

 sounds are narrower and more in the nature of lagoons, with even the latter 

 poorly developed southwest of Cape Fear. 



From the Virginia line to Cape Fear this offshore bar is interrupted by 

 about seventeen inlets connecting the ocean with the sounds. As controlled 

 by strong natural forces, these inlets open and close, migrate with the shifting 

 sands, and vary from shallow temporary washes to deeper more permanent 



