Salmon on the Columbia

When Salmon are Dammed

Ten to sixteen million salmon and steelhead once returned each year to the streams and rivers of the Columbia Basin. The Chinook salmon run was once the greatest in the world. Today, numbers have declined by 90%. The American Fisheries Society has reason to believe that around 36 runs of salmon and steelhead in the Columbia Basin are now at high risk for extinction.

Scientists estimate that about 70%-95% of human-induced deaths of salmon in the Columbia Basin are dam related. It is estimated that the Bonneville Dam claims 17% of adult salmon and 60% of juveniles.

Dams contribute to the destruction of the salmon population by:

  • Blocking and flooding salmon habitat.
  • Killing or stunning fish as they pass through dam turbines.
  • Increasing migration times, predation, and stress.

The destructive nature of the dam itself, overfishing, environmental degradation, non-native, introduced sport-fishing species, and land-use practices that impinge upon the salmon’s habitat are the real culprits behind declining salmon numbers. We can all help by conserving water and electricity and supporting dam modifications to recover healthy salmon runs.

*Data provided by Pacific States Marine Fisheries Commission and National Marine Fisheries Service.