140 American Fisheries Society 



Synopsis. 



1. The Salmon is a sea fish, and feeds in the sea, and maintains 



health and vigor in the sea, but loses condition, becomes 

 emaciated and often diseased in fresh water. Land-locked 

 varieties are abnormal and illustrate acclimatization, like 

 the fresh water shark of the River Amazon, or the lake ling 

 or cusk, which must have been marine at one time. 



2. The eggs and young of the salmon have through a long period 



of acclimatization become accustomed to their new environ- 

 ment, but the present gravel shallows at the head waters 

 were once sandy or gravel areas in marine bays or estuaries. 

 Geology teaches how such areas, the salmon's ancestral 

 breeding areas, have become by elevation, first brackish, 

 and finally pure fresh water areas. Smelt, shad, alewives, 

 striped bass and other species are marine, but come into 

 brackish or fresh water, at certain seasons of the year. 



3. The elevated spawning areas of the salmon have never ceased 



to have connection with the sea, and salmon rivers are the 

 persisting drainage channels, and have enabled the schools 

 of salmon to continue resorting to their ancestral breeding 

 areas though often involving very lengthy and perilous 

 migrations. 



