380 MARINE FISHERIES OF NORTH CAROLINA 



The production of the New England vessel fisheries is shown in the upper 

 line, Fig. 7. In this curve the salt fish have been converted (by the factor 2) 

 to fresh weights as usually landed. The middle line, void from 1908 to 191 5, 

 represents the total production of food fish and shellfish in the United States 

 (seven regions). The bottom line is the population of the United States. These 

 curves are all drawn to logarithmic scale in which like changes in per cent 

 are expressed by like slopes of curves regardless of amounts and sizes of units. 



Since the record of the vessel fisheries is both actual and annual, it shows 

 more deviation from year to year (continuous line) up to 192 1 than does the 

 total production curve which for the early period is considerably smoothed 

 by its method of derivation (68 per cent interpolated). The vessel fishery 

 curve shows the depressions of 1897 and 192 1, while the total food fishery 

 curve does not. To make the two curves more truly comparable, the vessel 

 fishery curve from 1891 to 1923 is therefore smoothed by a five-point moving 

 average (dot-dash line) . This smoothed curve of vessel fisheries and the partly 

 interpolated curve of production of all United States food fisheries are then, 

 for the period up to 1923, in good agreement. They are in still better agree- 

 ment when the salt fish in the total United States curve is converted by 

 approximation to fresh fish (dotted line). Both curves (even the unsmoothed 

 vessel fisheries) for the earlier period are smoother than either curve is for 

 the late period; the earlier period was a more tranquil economic period than 

 the later. 



Both New England vessel and national food fisheries failed to keep pace 

 with population until about 1922, in which year both reached a low point 

 with reference to population. Subsequent to 1922, little salt fish is involved 

 in either curve, neither is smoothed, both are based on good statistical records 

 and are in good agreement. The two curves, one representing a large but 

 local fishery of a dozen or so species and a few hundred fishermen, the other 

 (of which the first is about an 18 per cent component) representing national 

 production of more than 200 species of food fish by more than 100,000 men, 

 are in such close agreement as not only to validate the national curve and 

 the method of its derivation, but also to suggest that whatever is the deter- 

 minant of one is also the determinant of the other. 



In the numerous subsidiary tables presented herein in interpretation of 

 the above described main tables, wherever the procedure is not obvious, 

 explanations are made in the text or footnotes. 



Characteristics of the Fisheries as Indicated by the Data. Consideration 

 is here necessarily restricted mainly to food fish; the total of all fishery 

 products is considered only in comparing the performance of the geograph- 

 ical regions and of fishermen. The statistical history of food fisheries of 

 the United States is exhibited graphically in Fig. 5, on which the following 

 observations may be made: 



