RELATION OF RIVER LIFE TO SUBSEQUENT LIFE OF SALMON. 61 



Relation of the River Life to the Subsequent Life of the Salmon. 



The length of the river Hfe, or the period from egg to smolt, of the salmon, is said to 

 react upon the future life of the fish and even affects the fluctuations in the numbers of 

 fish composing the spawning migrations. It will appear later that it not only concerns 

 the individual itself but has its bearing upon its relation to other classes. 



Dahl (1918, p. 30) says that the smolts are not all of the same age, nor have they all 

 spent an equal time in the sea when they return for the first time to spawn. Some return 

 sooner, others later quite independently of the age of migration. On the other hand, 

 Calderwood (1930, p. 59-60) wrote that, ' . . . the longer a smolt remains in the river, 

 the shorter time does it spend in the sea, and the converse also holds true.' 



Writing of the salmon of the 'Minas system,' near the head of the Bay of Fund}', 

 Huntsman (1931, p. 19) indicates that they are small fish, saying that 79 per cent of those 

 examined had spent two years in the river and 89 per cent were evidently spawning or had 

 spawned as grilse. 'We conclude, therefore,' he says, 'that the small salmon of the head 

 of the Bay of Fundy are fish of which the great majority spawn for the first time as grilse, 

 and, that at that time they are only four full years old from spawning to spawning, as 

 compared with the prevalent five-year old fish in the Saint John, sLx-year old fish in the 

 Miramichi, and seven-or eight-year old fish in the Grand Cascapedia.' 



There are exceptions to the rule as ennunciated by Calderwood and are more in ac- 

 cordance with Dahl's conclusion that when the salmon return for the first time to spawn 

 the time is quite independent of the age of the smolt when it leaves the river for the 

 sea. It would appear that any regularity or irregularity in respect to the age at which 

 salmon first return to spawn may be dependent also upon other factors than the age at 

 which smolts migrate to the sea. 



The evidence thus far presented suggests that the phenomena are local and in some 

 instances, perhaps racial as indicated by what Huntsman has said regarding the Minas, 

 Saint John, Miramichi, and Grand Cascapedia rivers. Hutton was convinced that each 

 river had a race pecuUar to it. He says (1924, p. 29-30): 'I am firmly convinced that, 

 although all our salmon belong to one species, Salmo Salar (the true Atlantic salmon), 

 there are many types, varieties, or "races." ' He goes on even still farther than that 

 saying: 'Admitted, then, that each river has its own type or race, it is only a step further 

 to assume that there may be several races or types in any one river. Probably each 

 tributary will produce its own type. Further, I beheve that, generally speaking, each 

 class of salmon will reproduce its own class.' 



Gilbert (1918, p. 37) found this to be the case with the Sockeye salmon of the Frazer 

 River, and this is confirmatory evidence even though the Pacific salmons are quite 

 different 'tj'pes' of fish from the Atlantic salmon, for as related to the fundamental 

 principles of the phenomenon of an anadromy, the one shows no essential difference from 

 the other. It is clearlj' evident that, if there is always a preponderance of one certain 

 age-class of parr or smolts in a river, there must be some factors at work which regulates 

 the situation. It is noticeable from what has been stated by various investigators that 

 where only one age class occurs, or it is by far the dominant class, it is likely to be in 



