40 MANAGEMENT OF HIGH SEAS FISHERIES 



excessive, unregulated fishing for a stock such as halibut, which is 

 known to have a limited capacity for replenishment. If the stock is 

 heavily overfished, even for a short time, it can be reduced to such 

 low levels of abinidance that it is not economically exploitable. The 

 history of this species, as well as others, has shown that it is much 

 more difficult to rebuild a stock than it is to maintain it. When it 

 has once been heavily overfished only severe restrictions on fishing 

 effort, with consequent economic loss, will enable the stock to rein- 

 state itself. 



Another source of difficulty in the 1953 treaty concerns the loca- 

 tion of the provisional line at 175° West Longitude, to the east of 

 which the Japanese have agreed to abstain from fishing for salmon. 

 In the treaty this line was explicitly defined as "provisional." Con- 

 cerning its revision the treaty provides that "The Coinmission . . . 

 shall . . . investigate the waters of the convention area to determine 

 if there are areas in which salmon originating in the rivers of 

 Canada and of the United States of America intermingle with salmon 

 originating in the rivers of Asia. If such areas are found the Commis- 

 sion shall conduct suitable studies to determine a line or lines which 

 best divide salmon of Asiatic origin and salmon of Canadian and 

 United States of America origin, . . . and ^vhether it can be sho^vn 

 beyond a reasonable doubt that this line or lines more equitably 

 divide such salmon than the provisional lines. . . ." The United 

 States has endeavored to relocate this line, biu the Commission was 

 unable to reach agreement. It is now a well-established fact that 

 Asian salmon roam to the east of this provisional line, and North 

 American salmon roam to the west of it. It would appear that as long 

 as the line is left in the general vicinity of 175° West Longitude, 

 there is no way it can be drawn to limit the Japanese only to Asian 

 salmon. Then the question remains, what more "equitable" line can 

 be drawn? Presumably the term "equitable" here does not apply to 

 the problem of catching salmon when they are still only partially 

 grown, as they are on the high seas, and where, for that reason, there 

 is a considerable loss in the total poimdage of fish available. Because 

 of this last fact Canada and the United States have prohibited their 

 fishermen from catching salmon with nets on the high seas. Except 

 for catches of king and coho salmon by trollers, all salmon caught by 

 fishermen from this side of the Pacific are caught at or near the 

 mouths of the spawning rivers, inside territorial waters, where the 



