Steelhead Trout History
Anglers and nature lovers prize steelhead trout for their mystique and power. The Steelhead Trout ( Oncorhynchus mykiss ) is an ocean-going version of the rainbow trout, hence the same species name. The two names reflect two distinct life history patterns. The name rainbow trout is used for the non-anadromous life history. Rainbow trout do not leave the stream to go to the ocean. They spend their entire life in the stream. The name steelhead refers to the anadromous life history described above.
Oregon has two subspecies of steelhead (so-called because of the metallic appearance of maturing adults) or rainbow trout: a coastal form and an inland form.
Like the closely related cutthroat trout and chinook salmon, coastal steelhead have diverse, flexible modes of life. Some populations (steelhead) undertake long ocean migrations while others (rainbow trout) reside full time in freshwater.
Like salmon, steelhead are anadromous: they return to their original hatching ground to spawn. Unlike salmon, which die after spawning, steelhead rejuvenate after spawning so they may return to the oceans to start the anadromous cycle once again. The steelhead smolts (immature or young fish) usually remain in the river for about a year before heading to sea, whereas salmon typically return to the seas as smolts. Different populations of steelheads migrate upriver at different times of the year. "Summer-run steelhead" migrate between May and October, before their reproductive organs are fully mature. They mature in freshwater before spawning in the spring. "Winter-run steelhead" mature fully in the ocean before migrating, between November and April, and spawn shortly after returning. Similar to Atlantic salmon, but unlike their Pacific Oncorhynchus kin, steelhead are iteroparous and may make several spawning trips between fresh and salt water.The life-span of a rainbow trout is between 1 to 2.5years.
Different steelhead populations migrate during distinct portions of the year. Coastal steelhead are widely distributed from southern California (historically, even into Baja California) to the coast of Alaska's Bering Sea. In Oregon, coastal steelhead live their various life histories in most coastal and lower Columbia River streams (as far east as Hood River).
A typical mature coastal steelhead is slightly over 2 feet long and weighs 6 to 8 pounds, but many atypically sized fish ply Oregon's coastal streams, luring anglers to spend countless hours casting and hoping.
The Oregon Department of Fish and Wildlife considers most populations of coastal steelhead to have been in decline in the past two decades, partly because of unfavorable ocean conditions but also because of degraded freshwater habitat and the negative impacts of hatchery fish. The federal government listed the coastal steelhead trout as endangered throughout the Willamette River Basin and considers the populations on the Oregon coast as candidates for listing. In many of Oregon's coastal streams, more than 50 percent of the naturally spawning fish are of hatchery origin, which suggests that wild fish may be in even greater jeopardy.
The freshwater rearing period is critical for the survival of individual fish, so efforts to restore and conserve steelhead trout must focus on improving habitat in the watersheds where they live. We must also address other factors that threaten steelhead, such as harvest and hatchery effects.