This video segment from NOVA: "Sea Behind the Dunes" tracks the return of spawning alewife fish from the open ocean back to the freshwater streams and ponds where they were born. [3:34]

explore fast facts, physiology, habitats, behaviors, and range of the rainbow trout.

Learn fast facts, the physiology, habitats, behaviors and range of the Atlantic or Pacific salmon.

Learn fast facts, the physiology, habitats, behaviors and range of the tundra swan.

Investigate how scientists track the world's most valuable and endangered fish. Define the range of an individual based on observations made over the course of a day.