302 MARINE FISHERIES OF NORTH CAROLINA 



locally and generally. Such limit as there is, is in the amount of basic vegeta- 

 tion that is converted into useful fishes and other animals. There is, how- 

 ever, no evidence that the ultimate potentials of production are affected by 

 exploitation even if carried to the point of diminishing returns; there ap- 

 pears to be no reason to doubt that once the pressure of exploitation is 

 relieved in heavily fished areas the fisheries would return to their original 

 state. 



Agriculture, the source of most of the world's food and much of its raw 

 materials, is at its best and most efficient in the production of vegetable 

 crops; in feeding these crops to animals and in converting them into animal 

 protein and fat as meat, milk, and eggs, only a small percentage of the food 

 content is recovered (in terms of calories of energy), varying from 4 to 5 

 per cent as beef, lamb and poultry meat, 7 per cent as eggs, 15 per cent as 

 milk, and 20 per cent as pork. (Maynard, 1946.) In addition to this eco- 

 nomic loss, a great deal of labor and expense is devoted to cultivating the 

 crops and feeding and tending animals. 



The fisheries are at their best in the production of animal proteins and' 

 fats, the most expensive and most needed classes of food. Nearly all the 

 vegetation in the sea and larger lakes is microscopic and not now directly 

 useful to man; it must be transformed into animals large enough to be 

 useful; in this transformation (often in several steps) there are also large 

 losses as yet not accurately known, but apparently smaller at each step than 

 those in land animals.^ Whatever may be the biological efficiency or ineffi- 

 ciency in the production of aquatic vegetation and its transformation into 

 animal substance as fish, it may be disregarded for our purposes here since 

 it involves no labor or expense; from the economic point of view all the 

 factors of production of the fisheries are provided by nature; we need only 

 harvest the crop. 



Comparative Costs of Fishery and Agricultural Products. We have only 

 fragmentary data for direct comparison of the over-all costs of production 

 of meat and fish. In order that a comparison can be made, we assume that 

 first selling prices are comparably related to costs of production in the two 

 classes of products. Table 4 shows, for the United States in 1938-39-40, 

 the primary prices of fish and domestic animals. 



The National Research Council^ estimated the cost of production in 

 man-years for the lowest cost domestic animal food, i.e., growing corn 

 and feeding pigs in the most productive regions. The figures show 50,000 

 pounds of pigs on the hoof, or 32,600 pounds of edible pork and lard per 

 man-year. The exact figures for the most productive fisheries (North Atlantic 



2. For critical exposition and review of literature on efficiency of food conversion in fishes, see 

 Lindeman (1942), and Ricker (1946). 



3. Unpublished MS. See Food & Agriculture Organization, (1945). 



