364 MARINE FISHERIES OF NORTH CAROLINA 



1 700 calories per pound of protein and 5 per cent of fat having 4000 calories 

 per pound of fat, or about 500 calories derived from protein and fat per pound 

 wet weight of fish. If the edible portion is 18 per cent protein, fish would 

 supply 466 gm. protein per capita per year or about 6.7 days' recommended 

 allowance of 70 gms. per day.^° Assuming that all fish produce is human 

 food, the world production of about 5.7 pounds net edible fish therefore 

 appears to contribute about 2800 calories as a maximum or one day's adult 

 energy requirement, or 0.27 per cent of the required energy for each in- 

 habitant of the world each year, at the rate of less than one-half pound per 

 acre of ocean. This is a small amount of subsistence to be derived from the 

 71 per cent of the whole surface of the earth which is covered by sea and 

 receives 71 per cent of the sun's energy arriving on the earth and contains the 

 great bulk of the earth's fertilizers. The 139,295,000 square miles of ocean 

 area is 40.4 acres per capita of the world's population, the gross product of 

 which is only 266 pounds per square mile, or 0.42 pounds per acre.^^' ^^ 



The 57,655,000 square miles of land area of the earth, 16.8 acres per 

 capita, supports 2.2 billion people with a little less than 100 pounds of food 

 per acre, or over 99 per cent of the supply, and in addition the non-food 

 products of agriculture and forestry. On the average 2^ acres of cultivated 

 farm land supplies the subsistence for one person. (United States, 2.43 

 acres.) ^^ 



Various estimates have been made of the annual production or pasturage 

 of basic vegetable matter in sea water, one of which is 4,000 tons minimum 

 per square mile in the English Channel (literature cited and reviewed by 

 Harvey, 1928). Riley (1941, 1944) summarizes the literature and presents 

 original findings showing that the average basic production in Long Island 

 Sound involves the fixation of 375 grams of carbon per square meter of 

 surface per year which we compute (at C X i3-5 = wet plankton) is equiv- 

 alent to 14,400 tons of vegetables per square mile per year. For Riley's 

 estimated average production of the open ocean (340 grams total carbon 

 fixation per square meter per year) the vegetable production would be 13,100 

 tons per square mile per year. Riley (1941) reckons the animal plankton in 

 Long Island Sound at probably o.i to i.o per cent of the vegetables on which 

 it subsists, or, say, up to 140 tons per square mile, with an absolute maximum 

 of 17 per cent or 2,200 tons. The larger animals, including fish would, of 

 course, be a still smaller amount. With these figures may be compared our 



30. Nat. Res. Council, Food and Nutrition Board, Reprint & Circular Series, No. 129, 1948. 



31. See Taylor (1932) for a summary of the various magnitudes of the ocean. 



32. The above reckoning does not include whales, the world catch of which may be estimated 

 at about 10 per cent as much as the catch of fish. At the present rate of capture, regulated by 

 international agreement at 16,000 "blue whale units" (unit = i whale 100 ft. long) per year, the 

 yield is about 2 billion pounds of oil and 3 billion pounds of scrap and bones; about 2 billion 

 pounds of edible meat could be supplied by whales. Very little of it is now used for human food. 



33. See Cooper, Barton and Brodell (1947), p. 24, for details of farm acreage and its produce. 



