ATLANTIC SALMON 



27 



where the peak run of the two-year sea-life 

 salmon occurs three weeks later than at 

 Port-aux-Basques. 



The salmon probably follow definite 

 routes of migration in the Gulf of St. 

 Lawrence. Therefore, it is important to 

 know whether the commercial drift-net and 

 shore-net fisheries are so situated along 

 these routes as to take an excessive number 

 of salmon bound for definite sections of the 

 coast, thereby producing by overfishing a 

 diminution of the local supply. Effective 

 measures for salmon conservation depend 

 essentially on a thorough knowledge of 

 their habits and characteristics. 



The much disputed question of whether 

 or not the salmon returns to spawn in the 

 same river where it spent its life as a parr, 

 irrespective of the mechanism governing 

 its return, is not onlj^ of academic interest, 

 but is of practical importance for the con-' 

 servation of the salmon stock of individual 

 rivers. The facts presented in this paper 

 do not directly touch upon this question; 

 nevertheless, since they are concerned with 

 the characteristics and movements of the 

 salmon in the coastal areas of these rivers, 

 they have an almost equally important 

 bearing upon the problem of salmon con- 

 servation. 



Salmon Cycles 



In 1931 Huntsman (1) and Phelps and 

 Belding (2), independently and from en- 

 tirely different data, discovered that there 

 was a ten-year cycle of abundance in the 

 salmon of North America with its peak on 

 the years ending in five and its low point 

 on the years ending in zero. The causes of 

 this cyclic phenomenon, which is similar to 

 that reported in other wild animals by sev- 

 eral investigators, are still a matter of con- 

 jecture, although several apparently well- 

 founded theories have been advanced. 

 These cycles of abundance are chiefly re- 

 sponsible for our inability to determine ac- 

 curately from the statistics of the commer- 

 cial fisheries the inception of a general de- 

 cline in the salmon stock, since the cyclic 

 phenomenon tends to mask any immediate 

 diminution and necessitates dealing with 



periods of 10 or even 20 years before reli- 

 able conclusions may be drawn. 



In addition to cycles in abundance there 

 are annual fluctuations in the weight of 

 two-year sea-life salmon, the predominat- 

 ing sea-life class. These annual fluctua- 

 tions follow an erratic six-year cycle and a 

 long-term cycle of about 45 years. Such 

 cycles are not primarily concerned with the 

 salmon themselves, but apparently are due 

 to feeding conditions in the sea. The salmon 

 of several rivers in different parts of the 

 Gulf of St. Lawrence consistently show uni- 

 form annual variations of weight. Since 

 these annual fluctuations in weight are not 

 synchronous for the salmon of Canada and 

 Great Britain, it would seem reasonable to 

 assume that the salmon of the two hemi- 

 spheres do not inhabit the same oceanic feed- 

 ing grounds. 



Salmon Characteristics 



Considerable information has been com- 

 piled concerning the characteristics of the 

 Atlantic salmon in various parts of Canada 

 and Newfoundland. If due allowance is 

 made for annual and other variations, the 

 aggregate of these characteristics provides 

 a reasonable measuring rod for distinguish- 

 ing the salmon of one locality from those of 

 another. The most important differential 

 characteristics are: (1) the proportion of 

 large three-year sea-life maiden salmon; 

 (2) the percentage of previously spawned 

 salmon; (3) the duration of river-life, and 

 (4) the length of two-year sea-life maiden 

 salmon. 



The salmon of the Gulf of St. Lawrence 

 vary in their characteristics, which are dis- 

 tinctive for special sections. Even greater 

 differences in characteristics are found be- 

 tween the salmon of various rivers, a fact 

 which has strengthened the belief in the ex- 

 istence of river varieties or races and in the 

 return of a salmon to the river where it 

 lived as a parr. The characteristics of the 

 salmon of a particular locality are deter- 

 mined by the composite characteristics of 

 the salmon of its several rivers. However, 

 if the locality in question is not a terminus, 

 all salmon taken within its confines will 



