FOOD SHORTAGES AND THE SEA — MERRIMAN 381 



ample, the fishes will react differently according to their size, and 

 the problem of varying the voltage effectively may prove an obstacle, 

 although Kreiitzer discusses this feature only in terms of the conser- 

 vation of small fishes which are destroyed in normal trawling oper- 

 ations. Also, in his account, the gear, as applied to a special trawl, 

 sounds unwieldy and liighly impractical for operation at sea. More 

 fishing gear has been designed on land and failed in practice than 

 any skipper cares to think about. Electrophysiological fishing remains 

 to be demonstrated as a means of increasing the commercial catch, and 

 it must still be regarded with more than a little skepticism. 



In short, it is not j^robabie that inventions, new techniques, or 

 modifications of existing gear will immediately bring about such a 

 huge increase in the world's annual landings of fishes as to make 

 notable contribution to the need for protein. The increase in human 

 population appears to be outstripping the ability of science to pro- 

 duce by new inventions the requisite food — at least food from the sea. 



The expansion of present fisheries and the development of new ones 

 hold more promise in this regard. For example, the Japanese tuna 

 fisheries in the prewar period were of vast extent; in all probability 

 their precise magnitude will never be known. At present the United 

 States Fish and Wildlife Service has embarked on an extensive study 

 of the biology of the Pacific tunas and a survey of the potentialities 

 of this resource. The area involved is so huge and the problems so 

 complex that results are bound to be slow. However, it is certain that 

 expansion of our tuna fisheries, not alone in the Pacific but elsewhere, 

 will follow in time. Here again the degree of optimism in terms of 

 increasing the world's supply of protein should be restrained. Tuna 

 is costly to produce, and therefore it is not the sort of food that can 

 l^lay a large role in raising the standard of human diet in, let us say, 

 southeast Asia. Other fisheries— notably those devoted to the her- 

 ring and cod families, will unquestionably expand and develop in new 

 areas. 



The biological productivity of the ocean is incredibly high in cer- 

 tain localities, such as the west coasts of Africa and South America ; 

 the pattern of ctirrent in both places causes up welling from the bot- 

 tom resulting in a rich supply of fertilizing nutrients for use by the 

 phytoplankton. Thus the quantities of fish off Perti, where the Hum- 

 boldt Current exerts its influence, are phenomenal; the cormorants 

 on the three small Chincha Islands (once famous for their guano 

 deposits) have been estimated to consume each year a weight of 

 anchovylike fish equivalent to one-quarter of the entire United States 

 catch of all species. These areas are notably underexploited by man ; 

 surely our fisheries will in time exploit them to a much greater degree. 

 How can it be otherwise with Diesel and gasoline engines replacing 

 steam and sail, with a vastly increased cruising radius, radiotele- 



