North American Fishery Potential 



by P. A. Larkin 



Director, Biological Station 



Nanaimo, British Columbia 



Fisheries Research Board of Canada 



The North American fishery potential may be appraised in 

 various ways, which vary in the degree to which they take cog- 

 nizance of the biological, economic and political facts of life. 

 At one extreme, an unihibited enthusiast can describe a cornu- 

 copia of immense proportions, while at the other extreme a 

 pessimist may see less potential than we currently exploit. 

 Perhaps then it is most appropriate to paint a variety of pic- 

 tures, so that to some degree we may be able to assess the 

 various alternatives that might lie ahead. 



A current and fundamental approach, summarized with 

 effectiveness by Schaefer in 1964 and Chapman in 1965, begins 

 with the observation that the ocean covers about three-quarters 

 of the world's surface and receives, therefore, a like fraction 

 of the sun's energy. With appropriate calculations it ensues 

 that each year the world's oceans produce 19 billion tons of 

 living plant matter — mostly in the form of very small, single- 

 celled plants. This production, to be put in proper perspec- 

 tive, should be placed with our resources of pine needles, grass, 

 and autumn leaves and such, as a last-resort source of food 

 should we ever face the dire necessity. In general, this primary 

 production in the sea (in contrast to plant production on land) 

 is not in a form suitable for efficient harvesting by man, and 

 requires concentration by small herbivorous animals. These 

 plankton organisms, perhaps produced at a rate of more than 

 5 billion tons per year, are similarly dispersed widely in the 

 329 million cubic miles of the world's oceans. Again, then, 

 to put most of this production in perspective, it should be 

 added to the comparable resources on land, not to the cows and 

 other big herbivores, but to the beetles, caterpillars, earth- 

 worms and such — which are not at present harvested in most 

 places for various reasons of taste and economics. Even as- 

 suming we would like plankton if we were served it, there is 

 grave doubt that the calories we got out of it would equal the 

 calories we put into getting it. 



Some of these herbivores, such as shellfish, shrimp and small 

 species of fish such as anchovies, are major crops from the sea, 

 with enormous potential, but still another level of concentration 

 is usually necessary before the vast production of the world's 

 oceans is in a form suitable for man. This concentration is 

 made by the predators of the ocean — many species of fish 

 ranging from snappers to salmon, bonito to barracuda; many 



species of squid, whales, and their relatives, and the similar 

 larger animals which comprise most of man's present harvest 

 from the sea. 



We now, then, may construct a more meaningful picture. 

 In this vast watery factory that converts sunshine into food, 

 what is the potential annual production at the level at which 

 man (as an animal) seems likely to operate? The answer 

 appears to be somewhere between 1 and 2 billion tons, which 

 converted into protein foods is more than adequate for ten 

 times the world's present population of 3 billion people (Chap- 

 man, 1965). 



The next obvious question is — "will this amount, combined 

 with the production on land, be enough?" — for what will the 

 world's population be, when we bear in mind that there are 

 some things you can't make unpopular? It has been argued 

 that man is a social animal and his population will be regu- 

 lated by social forces; to think otherwise is to ignore both 

 evolution and history. World population for various reasons 

 might, we are told, level off at 30 billion, also roughly 10 

 times the present population. Accordingly, to bring this as- 

 sessment to a conclusion, we surmise that the world's oceans 

 could suffice if called upon to save mankind from a global 

 famine. 



It is of interest in passing to note that the present world catch 

 approximates 50 million metric tons, certainly less than one- 

 tenth of the potential catch and perhaps as little as one-fortieth. 

 Similarly, I presume, there are opportunities for very much 

 greater production of human food on the land masses of the 

 world. 



These speculations are important to philosophers and to tho^c 

 of us who will live into the 21st century, but for the purposes 

 of our present conference it's perhaps better to come to closer 

 grips, to ask the question : What is the potential on the coasts 

 of North America for developing fisheries of the kind that 

 men have developed and are developing in various parts of 

 the world? 



As a continent, North America is no different from most, 

 oceanographically speaking. It has endowments, coast for 

 coast, which compare reasonably favorably with the other 

 continents. Patterns of oceanic circulation, areas of continental 

 shelf, factors of climate and weather, characteristics of the sea 



1 



