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Introduction 



Sockeye and chinook from the Snake River, the Columbia's largest tributary, have 

 been listed for protection under the Endangered Species Act. But many of those committed 

 to helping save Columbia River salmon question whether the National Marine Fisheries 

 Service (NMFS) will effectively use the act to rebuild the salmon species now facing 

 extinction. They fear that a recovery plan will be too many years in the making and that it 

 and other protective measures will not be enough. They also worry that scientific debate and 

 uncertainty over questions about "si)ecies'' definitions and the role of genetics will be used to 

 slow or even sabotage salmon restoration. This article describes what some of that debate is 

 about and what the implications are for Columbia Basin salmon. 



Species Definition 



A widely accepted scientific definition of a species is derived from the biological 

 species concept which emphasizes that members of the same species interbreed. In other 

 words, for most animals and many plants, a species is a group whose members breed within 

 the group, but do not usually breed with members of other groups. A biological species is 

 said to be reproductively isolated. (Templeton 1989). 



Within a species there are no major differences in genetic composition nor in 

 characteristics strongly controlled by genes. Minor differences may occur, and a group 

 exhibiting those different characteristics may be classified as a sub-species. Such differences 

 often arise because of geographic separation. When geographic separation continues and 

 (genetic) differences increase, a sub-species may evolve traits that enforce reproductive isola- 

 tion. At this point, a subspecies may be recognized as a new species. 



Zoologists do not officially recognize groups below the subspecies level (Stace 1989). 

 However, it is often desirable and useful to recognize groups such as races and varieties. The 

 terms refer loosely to minor differences within a species, for example, stocks of salmon. The 

 variety or race is often recognized by ecological characteristics, such as differences in the 

 migration timing of spring, summer, and fall chinook. 



The Endangered Species Act also allows for protection of a "distinct population 

 segment. " Under the act, a distinct population segment can be protected using a wide range 

 of criteria (geographic, economic, aesthetic, political, biological among others), provided 

 group members can interbreed when mature. Because Congress defined "distinct population 

 segment" in only very broad terms, the National Marine Fisheries Service (NMFS) felt 

 obligated to establish a policy that would explain how "distinct populations segment" applied 

 to Pacific salmon (Waples 1991). 



In 1991 NMFS (56 F.R. 58612) declared that a distinct population segment would be 

 recognized only if the interbreeding population met two criteria: "0) It must be substantially 



