Why is Pacific salmon movement into freshwater streams considered migration if the salmon die at the head of the stream and never return to the ocean?
A)It is not considered migration but immigration.
B)Migration is a one-way movement.
C)Because their offspring return to the ocean,the entire population participates in the migratory event via different life stages.
D)Most male adult fish survive reproduction and return to the ocean.

Question

Quizplus · Accepted Answer

While individual Pacific salmon do not complete a full round trip migration, the overall population participates in a migratory event as the offspring of the salmon will eventually return to the ocean to complete their life cycle. Therefore, the movement into freshwater streams is still considered a migration.

Why Is Pacific Salmon Movement into Freshwater Streams Considered Migration