ECONOMICS OF THE FISHERIES 365 



five tons of fish ultimately derived from this vegetation in United States 

 coastal and inland waters, and only 266 pounds per square mile of the whole 

 ocean.^^ Riley concludes that the production of vegetation per square mile 

 at sea is considerably higher than that of forest or cultivated land (160 grams 

 of C on cultivated land, 200 to 250 in good forests, corresponding to 4;900 

 and 6,120 tons, respectively, of wet vegetation per square mile). 



Comparative Magnitudes of the United States Fisheries. In recent years 

 the gross yield of the commercial fisheries of the United States and Alaska 

 has ranged from 4 to 4>< billion pounds or 2 to 2>4 million tons annually, 

 valued (1940) at about $100,000,000. This amount is about 11 per cent of 

 the estimated world production of 37 billion pounds.'^ While seemingly large 

 (and increasing with increasing human population), this gross yield appears 

 to be small not only by comparison with the fertility, productivity and area 

 of the waters concerned, but also with the yield of the fisheries in other parts 

 of the world, with the yield of competing products of agricultural origin on 

 land, and with numerous other criteria of measurement. 



The area of the continental shelf of the United States proper (narrow 

 under-water offshore ledge or fringe of the continent out to the lOO-fathom 

 line) is about 300,000 square statute miles; that of the southeast and 

 southern shore of Alaska (Dixon's Entrance to Attn Island) about 150,000, 

 and the inland fresh waters including the Great Lakes, about 100,000 square 

 miles. ^^ In addition, there are sounds, bays, and estuarial inshore waters, and 

 certain offshore banks of a few thousand square miles.'" Also, some of the 

 yield from pelagic (surface swimming) species (such as tuna, mackerel, 

 herring, etc.) is taken at sea beyond the shelf. For a roughly indicative cal- 

 culation, however, we may take the area of the shelf as our source of fish in 

 the United States. On this basis, and at an annual total of 2 million tons of 

 fish, our waters yield about 10,000 pounds or 5 tons of produce per square 

 mile, or 15.6 pounds per acre, of continental shelf. This quantity, while 

 small, is much larger than the average of world production if reckoned per 

 square mile (266 pounds) or per acre (0.42 pounds) of the whole ocean. 

 This 5 tons of fish per square mile appears exceedingly small when compared 

 with the estimated 10,400 tons of vegetation per square mile of open sea, 

 and 14,000 tons in Long Island Sound. 



Recalling again Riley's estimate that this production of basic vegetable 

 food at sea is about twice what it is on cultivated farm land (10,400 tons of 

 wet vegetation at sea, 4,900 tons on cultivated land), it is interesting to 



34. Seiwell (1935) estimates the carbon fixation even of the relatively poor waters of the 

 tropical western Atlantic (between 14 degrees N. and 3 degrees N. along the 40th meridian) at 

 278 gm. per square meter per year. 



35. Food and Agriculture Organization, 1945. 



36. Information supplied by U. S. Coast & Geodetic Survey. 



37. The New England offshore banks, including the Grand Bank of Newfoundland, have about 

 75,000 sq. mi. area. 



