THE FUTURE OF OCEANOGRAPHY — SPILHAUS 363 



fishery research must give us an estimate of productivity which would 

 let us plan the size of the harvest so that it would be constantly con- 

 served and renewed, at the same time it is being used. 



But, once we establish tlie present productivity of the sea, we need 

 not stop there. Agriculture on land has made tremendous increases in 

 productivity per acre by growing single stands instead of mixed 

 populations, by breeding special strains adapted to a particular locality 

 and resistent to disease, by renewing tlie land by plowing, fertilizing, 

 and irrigating. Ail of these methods have their counterparts in aqua- 

 culture, the farming of the sea. Behavioral research on marine 

 animals' reactions to stimuli — electrical, acoustical, chemical, physical 

 bubbles and currents, and temperatures — all point the way to the 

 kind of "fences" we may use to isolate species and special breeds and 

 harvest them more readily than do present fishermen who merely 

 hunt them. 



The nutrients needed by life in the sea are presently renewed and 

 concentrated by various processes of nature. When we understand 

 these, we may be able to emulate them in artificial processes. Winds 

 drive away surface water in the lee of a coast, bringing up nutrient- 

 rich lower water. This suggests that barriers placed in the open ocean 

 might form artificial lees with rich patches of water around them. In 

 the open ocean when winds diverge, they also bring up bottom water 

 at the center of the divergence, and the natural stirring of currents 

 plows the sea. Perhaps we can "boil up" the nutrient-rich bottom 

 water by putting a nuclear stove down there. Possibly the waste 

 heat of an underwater nuclear powerplant for submarine beacons for 

 navigation could be used for this. Without aquaculture, the problem 

 in the sea is similar to the problem of gathering food from the wild 

 mixed animal and plant life in the undeveloped tropics. It is simply 

 that the desirable foodstuffs, plant or animal, are widely scattered 

 and hard to gather. Some way must be found to concentrate or herd 

 them. We shall need "shepherds" and "cowboys" in the sea. Perhaps 

 they will ride bucking one-man submarines, or perhaps as a result of 

 the present behavioral studies, we can train dolphins as sheep dogs 

 of the sea. 



The difference between wild scrub cattle and the highly bred, heavy 

 beef cattle is a result of selective breeding, good pasturage, and sup- 

 plemented feeding. Fish husbandry can do the same for fish in isolated 

 areas of the sea. 



Present-day fishing methods are mainly of two types, either netting 

 fish, which are closely gathered in schools, or hooking them with bait. 

 How fish respond to stimuli points the way to powerful new methods 

 of fishing and shows that the fish will line up and swim toward one 

 pole in a field of electric current. "Electric fishing," already practical 

 in fresh water, requires greater currents in the ocean water electrolyte ; 



