70 



face of even a moderate kill, not how to utilize them more fully, is 

 now a crying problem. 



The past quarter century has seen a rapid increase in the inten- 

 sity of fishing in the North Atlantic, in response to the increasing 

 demand for fish, favored by more effective rxiethods pf harvesting the 

 catch, by improved transportation, and by teetter systematized market- 

 ine. For all these reasons the demand for sea food, and for the by- 

 products of the Fisheries (oil, soap, fertilizer, leather, etc.) will 

 continue to increase; to meet this increasing demand, the stock of 

 herring, cod, haddock, halibut, lobsters and the rest will be subjected 

 to a more and more intensive drain. The intensity of the British 

 Steam Trawl Fishery, for example, increased by lljo from 1913 to 1920. 

 Yearly, more and more fishing is done on the American side of the 

 Atlantic with better and better gear, resulting in a corresponding 

 increase in the yearly catch. And wherever in the sea fishermen can 

 catch their fares, the story will soon be the same, if it is not so 

 already. Under these circumstances, the questions immediately urgent 

 of solution are: (l) how m^uch fishing can each species stand without 

 depletion at the hends of man; (2) what measures of regulation should 

 be taken to prevent depletion when danerer of the latter seems imminent 

 or to restore a depleted stock; (3) what is the possibility of extend- 

 ing the fisheries to new erounds; (4) what hope is there of marketing 

 fish, or other marine products not utilized at present; (5) can we 

 find a rational oasis for predicting in advance the great fluctuations 

 in the abundance of fishes that are known to occur from natural causes 

 and thus order our fishing efforts more economically. 



The first of these questions is the basic problem in all economic 

 fisheries research, for on the answer to it must depend the whole 

 scheme of intelligent use and conservation. But the answer in any 

 given case can only be reached by intensive study of the general 

 biology of the species in question, combined with actual experience as 

 expressed by the statistics of that particular fishery. 



The history of the fisheries includes sundry examples of deple- 

 tion; not only of the whales, just mentioned, but also when one or 

 another fish, crustacean, or mollusk has been fished down to a point 

 where pursuit was no longer profitable on grounds which yielded abun- 

 dant fares when first exploited. 



In North toerican waters the halibut perhaps affords the most 

 striking example of this. For the Atlantic, the annual catch brought 

 in by the New England Fishermen from the Banks off the Gulf of Maine, 

 off Nova Scotia, 'and to the north and east, having fallen from about 

 fifteen million po^onds in 1379, to three million pounds in 1926. 

 In the North Pacific, too, it is certain that a decline in tne cgtch 

 of halibut on the older grounds from nearly 300 pounds per unit of 

 gear in 190S to less than 50 lbs. in 193S, and the fact that no m.ore 

 fish are now taken off an 1800 mile stretch of coastline than were 

 formerly caught along SOO miles, has directly resulted from over- 

 fishing. The speed with which an over-drain on the stock is reflected 

 in the'^fishery for the halibut may also be illustrated by the fact 

 that newly developed grounds in the Pacific that yielded 160 lbs, per 

 unit of gear in 1923, yielded only 100 lbs. three years later, and 

 less still in 1927. It seems equally certain that the great decrease 

 in the catch of albacore off California also reflects too intensive 



