Fish 



ATLANTIC SALMON 



Common Name: ATLANTIC SALMON 

 Scientific Name: Salmo salar 



Species Status: Proposed as Threatened 



Species Trend: Decreasing 



Current Estimated Population: Approximately 160 adult returns in 1996 



SPECIES POPULATION STATUS 



One distinct population segment composed of seven river populations of Atlantic salmon were 

 proposed for listing as threatened on September 29. 1995. The seven Maine rivers are the 

 following: Sheepscot. Ducktrap. Narraguagus. Pleasant, Machias. East Machias, and Dennys 

 rivers. 



NMFS and USFWS determined that the Atlantic salmon populations in these seven rivers are, as 

 a group, reproductively isolated and discrete. Naturally-reproducing Atlantic salmon in U.S. 

 rivers are substantially reproductively isolated form those in Canada. A critical factor in 

 determining the significance of the river populations of U.S. Atlantic salmon was the continuous 

 persistence of a substantial component of native stock reproduction. The continuous presence of 

 U.S. Atlantic salmon in indigenous habitat provides evidence that important local adaptations 

 have persisted. At present, differences are subtle and difficult to assess due to low abundance. 

 Within the LJ.S.. Atlantic salmon populations exhibit strong fidelity to natal streams. An 

 examination of U.S. populations of Atlantic salmon provides evidence of their distinctness from 

 stocks in Canada and northern Europe. 



The original range of Atlantic salmon in the United States was from the Housatonic River in 

 Connecticut, north to U.S. tributaries of the St. John River in New Brunswick. Canada. The 

 historic Atlantic salmon run in the United States has been estimated to have approached 500.000 

 fish. The species began to disappear from U.S. rivers 150 years ago and currently, only remnant 

 populations occur in a limited number of rivers in Maine. Throughout the past 24 years, the 

 Denn\s and Narraguagus rivers ha\e had returns that averaged 20 percent of the escapement 

 goal, and the Pleasant. Sheepscot, and Machias rivers have had returns that averaged between 10 

 and 12 percent of their escapement goals. However, recent downward trends in abundance have 

 put most of these seven rivers at less than 10 percent of their respective escapement goals. The 

 combination of low relative abundance and low numbers relative to spawning requirements 

 demonstrates that the distinct population segment ma>' warrant protection under the ES.A. 



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