ATLANTIC SALMON 



Salmo salar Linnaeus 



Richard E. Cutting 



Atlantic Salmon Commission 



Atlantic salmon were originally distributed on both sides of the 

 Atlantic Ocean from Portugal north into the White Sea on the European 

 continent and from the Delaware River north into Hudson Bay on the 

 North American continent. The number of Maine rivers originally 

 supporting salmon runs exceeded 20. That number has declined to less 

 than nine, although stray fish appear in other streams. Dams that block 

 migration of mature adults upstream have been the major cause of de- 

 cline. Atlantic salmon must reach the spawning and nursery areas if 

 thriving populations are to be maintained. 



The majority of adult Atlantic salmon enter rivers in the spring tak- 

 ing advantage of the freshets occurring at this time, although fresh-run 

 fish in September and October are common. A good salmon river should 

 have cool, deep, shaded resting pools where adults are protected until 

 spawning time in the fall. Fresh-run salmon are silvery with a light 

 green-brown back. Maturing fish in fresh water become mottled and 

 darker; the back takes on a dull brownish-red hue and the underside be- 

 gins to tinge with dull red. Mature males also possess elongated jaws 

 with a prominent hook, or kype, at the tip of the lower jaw. 



Ahhough Atlantic salmon do not necessarily die after spawning it 

 is certain that the majority are making their first spawning migration 

 and are referred to as maiden fish. Approximately 85 percent of the 

 fish are returning to fresh water for the first time and are usually at 

 least four or five years old. Small salmon weighing up to five pounds 

 have spent only one year in the ocean and are known as grilse. Grilse 

 are sexually mature and almost invariably males. Unusually large fish 

 may be either returning to spawn again or fish that have stayed an extra 

 year or two in the marine environment. 



Adult Atlantics begin their spawning runs in the spring, but the 

 actual spawning period extends from October through into November 

 with peak activity during the last week in October. A river must pro- 

 vide adequate riffle areas of gravel and rubble with clean, cool running 

 water to insure successful natural reproduction. Ripe females will 

 choose a nesting site at the head of a riffle or the tail of a pool where 

 the water is accelerating. Nesting areas of salmon and trout are fre- 

 quently referred to as redds. Each nest or redd contains several egg pits. 



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