Salmon Predators

Fish predators such as northern pikeminnow prey on smolts as they try to negotiate the slower moving reservoirs. Pikeminnows are native to the Columbia/Snake Rivers. They were less effective predators in a river environment, but once the reservoirs were established, their feeding efficiency increased.

Birds such as cormorants, terns, gulls and pelicans are known predators on smolts in the reservoirs and estuary. The greatest effect of avian predators in any river/reservoir reach occurs in the Columbia River estuary because of the larger size of the bird colonies. The birds are attracted to man-made islands created from channel dredging for nesting.

Pinnipeds - sea lions and seals - also feed on adult salmon below Bonneville Dam where they stage during the migration. Population specific impacts are difficult to measure.

Salmon Predators

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