What constitutes a salmon population?
Even among biologists, the term “population” has been defined in a variety of ways. In its most general form, a population of salmon is defined as a group of fish of the same species that occurs in a given habitat. The NMFS defines a salmon population more specifically as a group of fish of the same species that spawns in a particular lake or stream at a particular season and which does not interbreed substantially with fish from any other group spawning in a different place or in the same place at a different season. For salmonids, two groups are considered to be independent populations if their level of interbreeding does not substantially alter either group or affect their risk of extinction over a 100-year time frame.
