It’s almost silver salmon season on the Columbia, and that means another season for anglers to pursue encounters with this remarkable fish. But what is a silver salmon, anyway?
We’ve talked about the silver, or coho, salmon (Oncorhynchus kisutch), before, but this time we’re going to dig a little deeper into the lives and natural history of these fascinating gamefish.
Historically, silver salmon were found throughout the North Pacific, from Central California to Point Hope, Alaska, to the Aleutian Islands, and beyond to the Anadyr River in Russia and finally the northern island of Hokkaido in Japan.
Today they still have major spawning grounds in Oregon, Washington State, British Columbia, and Alaska. They have also been introduced to Lake Eerie, and spawn in some of the tributary rivers leading into that lake.
Like salmon generally, silver salmon are anadromous, meaning that they spawn in freshwater, and the young subsequently migrate to the sea where they mature before swimming upriver to repeat the cycle.
To be more specific, young silver salmon typically live in freshwater until the spring of their second year. During their time in freshwater, they eat a steady diet of zooplankton, insects, and, especially as they get a little bigger, other small fish.
After migrating to the ocean as smolts, silver salmon spend 16-20 months growing to maturity. During this time, they eat small crustaceans, such as krill, and small fish.
Typically, silver salmon return from the ocean to spawn in the summer to fall, now aged 3 years. At this point, a typical wild fish may be about 8 pounds on average.