What affects salmon migration?
In recent years, studies have shown that in the open ocean environment, salmon use the magnetic field of the Earth to guide their migration. This helps them move from the coastal areas near their spawning grounds to rich feeding areas, and then back again toward the end of their lives.
How do humans affect salmon migration?
Humans have strong and often negative impacts on salmon. Over fishing has led to a decline in some salmon stocks. Land development and dam building have damaged habitats and impacted salmon runs. This development has led to a decline in salmon populations in some areas.