36 SEA GRANT COLLEGES 



Where existing advanced methods have been used in fishing, there is al- 

 ready the danger of overfishing- -of making the whales become extinct--and this 

 implies the urgent need, before we go much further in harvesting the living re- 

 sources of the sea, to have a way of keeping an inventory of all the species we 

 take from the sea so that we may be sure that they are renewed each year. And 

 also to get an idea of how much we can increase the sustained yield when we 

 intervene. 



In gathering the living things of the ocean, ocean engineers shouLd consider 

 whether other living things themselves, may do our building and collecting more 

 efficiently than mechanical machines that we can devise. It would be very ex- 

 pensive to collect enough euphausid shrimp, but whales collect and convert them 

 very efficiently. Perhaps we should be breeding whales instead of exterminating 

 them. Can we accelerate the coral animal to build reefs? Can we use shellfish 

 to concentrate minerals? Can we plant seaweed to stabilize beaches? Can we 

 hybridize the plants that grow in sea water, the seaweeds, and use them much 

 more extensively as sea fruits and vegetables? Perhaps we can even contribute 

 to the land by using the wealth of information on halophytes-- salty habitat 

 plants- -not only to grow useful food in sea or brackish water but actually to de- 

 salinize water by the use of plants which concentrate salts within them. Seaweed 

 is a good source of iodine, for instance. 



These are the beginnings of farming the plants of the sea, but what about 

 the animals? Plants are easier to farm and harvest because they may be rooted 

 or even if they are floating they are easy to control. Shellfish, which are indeed 

 farmed, are the next easiest for the same reason. Oysters, clams, and shrimp 

 are cultured to a greater or lesser extent in ponds and semienclosed arms of 

 seas. Next it is not much of a step to conceive of lobster traps on the bottom of 

 the continental shelf, acres in extent- -in fact, bottom fishes in general would 

 seem to be most easily susceptible to fencing. Then how do we fertilize the sea? 

 There are two ways in land farming; namely, plowing and adding nutrients. The 

 counterpart of plowing in the sea is upwelling that brings nutrients from deeper 

 water to the euphotic zone. The idea of doing this artificially by heating up the 

 ocean with a nuclear reactor at the bottom has been thought of, but on analysis 

 does not seem economical. But the waste heat from nuclear reactors for other 

 purposes may well be used in this way. The motions of the sea itself, which in- 

 deed cause upwelling notably in such productive waters of the Humboldt Current, 

 may be studied and ocean engineering intervention may devise ways of making 

 the sea plow itself more efficiently. 



How can we fertilize the sea? It is manifestly impossible to add sufficient 

 of the basic nutrients to open sea water, although this is possible in estuarine 

 or pond water. In the sea it's stirred and mixed away, unlike the use of ferti- 

 lizer on land. It does seem possible, however, to add the trace substances once 

 we know which are most important to growth. The study of trace elements, too, 

 will lead us to more successful transplantation of useful fishes from one area of 

 the world to another. Then, too, by using what the marine scientists know about 

 the food chain, we can eliminate some of the unnecessary and less useful species, 

 that is, intervene in a way that might be called "weeding the sea." 



One other aspect of the use of the sea which is already with us and may 

 grow even faster and stimulate ocean engineering more than these "naore seri- 

 ous" uses of the sea is the important part the sea can play in recreation of the 

 people in an increasingly crowded land world. Already you can purchase a small 

 sporting submarine for not much more than the cost of an automobile. Thou- 

 sands of people go down in the sea in aqualungs. Millions of dollars are spent 

 on boats, elaborate fishing equipment and underwater cameras for people's 

 recreation at sea. 



Perhaps some of the first underwater structures will be for recreation. 

 As mass-produced underwater vehicles come within the reach of ntiany, under- 



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