Oregon Explorer Topics | oregonexplorer

Salmon and Other Fish

Climate, Water, and Air

Coast Salmon Species

Seven species of salmon (all members of the scientific genus Oncorhynchus) are native to Oregon, but this group includes many subgroups with very different biological characteristics. The species of salmon are:

Coho
Chinook
Chum
Steelhead
Coastal Cutthroat Trout
Sockeye
Pink (No breeding populations of pink salmon are left in the state, although a pink salmon occasionally appears in the Columbia River.)

Coho Salmon
Coho Salmon (OSU Extension)	Juveniles rear throughout watersheds, often concentrating in pools in the summer, spreading out in the winter Juveniles migrate to the ocean at one year, in the spring Most Oregon coho rear just off our coast Adults return to fresh water in the fall and spawn in late fall and winter Adults tend to spawn in concentrations on gravel bars in small, relatively low-gradient tributary streams Most adults spawn when they are three years old
Chinook Salmon
Chinook Salmon (OSU Extension)	Distribution includes coast and Columbia Basin mainstem rivers Juveniles migrate to the ocean the first fall after they hatch, rearing briefly in estuaries They rear over a broad ocean area, ranging from northern California to the Gulf of Alaska. Adults, typically three to five years old, return to fresh water in the spring, summer or fall Spring and summer migrants prefer deep, cool pools where they hold several months before fall spawning Adults spawn in large concentrations on mainstem gravel bars; may use both upper and lower mainstems
Chum Salmon
Chum Salmon (OSU Extension)	Shortest freshwater residence of all salmon. Adults stay only about a week prior to spawning; juveniles migrate to the ocean hours after hatching Juveniles rear briefly in estuaries Most Oregon chum migrate to the Gulf of Alaska for ocean rearing Adults spawn at three to five years of age Spawning occurs in lower mainstems, concentrated on large gravel bars Adults are unable to pass even minor barriers
Steelhead Trout
Steelhead (OSU Extension)	There are two subspecies of steelhead in Oregon. Each also has a resident form. Coastal steelhead are closely related to rainbow trout. Inland steelhead are closely related to redband trout Most juveniles rear in fresh water for one or two years and migrate to the ocean in the spring Most steelhead spend two years in the ocean. Their distribution is poorly known but appears to be further off-shore than other salmon Most inland steelhead return to fresh water in the summer while most (but not all) coastal steelhead return in the winter Summer-run steelhead require cold deep pools where they hold until spawning. All steelhead spawn in the winter and may spawn more than once
Coastal Cutthroat Trout
Cutthroat Trout (OSU Extension)	Some coastal cutthroat migrate to the ocean. But others may migrate only to the estuary or river mainstems, or they may not migrate at all Those that do go to the ocean migrate out in the spring, stay only a few months close to shore, then return in the fall The ones that migrate may rear in fresh water for several years before going to the ocean They spawn in the winter and early spring, using small pockets of gravel. They may spawn more than once. The spawning age of cutthroats seems to vary over their distribution area Cutthroat prefer the smallest, highest tributaries in a basin

Of these species, chinook, coho, and chum salmon are found in the North Coast Basin, along with steelhead and cutthroat trout.

Biological differences within each of these species and subgroups of them contribute to the complexity of the salmon issue. Different forms of each of the above species have adapted to different aquatic environments.

For example, some forms of a species can be "anadromous," meaning they were hatched in fresh water but spend a large part of their lives in the ocean before returning to fresh water to reproduce. Yet other forms of the same species live in fresh water throughout their lives. For instance, rainbow and redband trout, which remain in fresh water throughout their life cycles, are "resident" forms of the steelhead species.

Also, some groups of anadromous fish travel from the sea into fresh water at different times of the year. Thus, there are "spring chinook" and "fall chinook" in some rivers. Sometimes these are called different "runs."