YEARS IN THE SEA. 53 



salmon is also learned from its scale. Thus by a scale it is possible to determine how long 

 the salmon remained in the river before it went down to the sea as a smolt, how long it 

 remained in the sea until it returned to spawn for the first time, and any further duration 

 between spawning periods that there may be. Then by measurements the increase in 

 length each year is also learned, as well as the probable condition of the fish during any 

 year of its Ufe. 



Notwithstanding the early fish cultural interest in the Atlantic salmon of New Eng- 

 land, the continued fish cultural propagation of the fish at one federal hatchery in Maine, 

 and its potential commercial and angling value, no attempts to solve the many problems 

 connected with the salmon have been made since those of Atkins over one-half a century 

 ago. But in Great Britain continuous study of the salmon questions have been main- 

 tained for years up to the present time. 



In previous pages mention was made of the researches of a number of investigators of 

 salmon, among whom were Miescher-Rusch, at Basel, and Noel Baton in Scotland. In 

 more recent years wonderful advances have been made in the study of the life history 

 of the salmon by numerous workers, such as Johnston, Hutton, Calderwood, Armistead, 

 and others in Great Britain and particularly Scotland; Hoek in Holland; Dahl in Norway; 

 Nordquist in Finland; Rodd, Huntsman and others in Canada. 



So much has been learned concerning the salmon through these and other authorities 

 that, in the words of Brof. J. Arthur Thomson (1924, p. vi) : ' . . . its life-history is known 

 with more precision than that of any other fish, unless it be the eel's.' Basically the Ufe 

 history of aU Atlantic salmon, whether of Great Britain, continental Europe, or North 

 America, is the same. But it varies with salmon of different countries with different 

 rivers of the same country, and even with different sections or branches of the same river. 



Years in (fie Sea. 

 Dahl (1910, p. 39) found that everywhere throughout the country where observa- 

 tions had been conducted, by far the largest majority of salmon examined were fish 

 which had never spawned and had remained in the sea from one to three, and excep- 

 tionally four, winters, and which were therefore in their second to their fifth summer 

 after migration to the sea as smolts. He says: 'These fish spawn in the second to the fifth 

 winter after migration, and apparently only a portion of them — chiefly composed of 

 the younger fish — ■ survive the spawning journey and the actual spawning. This little 

 band of survivors returns again to the sea, and some of them after the lapse of one year, 

 others after two years, and very few after three years interval, return to spawn for the 

 second time. Only an infinitesimal portion of these, about one in a 1,000, have shown 

 that they have returned to spawn for the third time.' He further showed (p. 38-39) 

 that, 'it is chiefly the fish which have spawned at an early age that return to spawn for 

 a second time. The great majority of the fish which in the summer are two or three 

 winters old and which spawn for the first time in their third or fourth winter, very seldom 

 reappear in the form of fish with a spawning mark. This, evidently points to the fact 

 that few of the older fish survive more than one spawning.' 



