CSA is restarting its monthly “Fish Blog”! We will start by profiling the state saltwater fish for all coastal states in the U.S. We are kicking it off with the Chinook (king) salmon, the state fish of Alaska and Oregon.

Life of Oncorhynchus tshawytscha

Salmon dominate the finfish fisheries of the Pacific Northwest. From their dramatic upriver migrations to the striking physical changes they undergo before spawning, they are iconic. Yet only one species carries the title of “king salmon”.

Oncorhynchus tshawytscha—better known as the king or Chinook salmon—is the state fish of Oregon and Alaska. These powerful fish can exceed 50 lb, with some recorded at more than 100 lb, hence the name “king”. Chinook salmon inhabit major river drainages across both states, particularly the Sacramento, Klamath, and Columbia. Their common name honors the Chinookan people, while the scientific name reflects terms used by indigenous groups in Alaska and Siberia.

Chinook salmon have several features that make them fairly easy to identify. They have the classic long, fish shape and a clear lateral line that runs lengthwise along the midline of the body. One of the most distinctive traits is the maxilla—the upper jawbone—which extends far enough to be visible from the outside, almost like a mustache. While all fish (humans too) have a maxilla, few of them have a maxilla that you can see on the outside of the fish, making it useful for identification. To further help in identification, fresh from the ocean or outside of the spawning season, Chinook salmon are bright silver with black spotting on the back and tail, and black gums; the back might appear a little purplish. As they migrate upstream into freshwater and prepare to spawn, their appearance changes dramatically; their flanks turn red and in males the upper jaw grows into a pronounced hook.

Chinook salmon may return to their natal streams in spring, winter, or fall, depending on their genetic background. These return times are used to classify and help manage populations. For example, salmon that return in the spring are known as the spring-run.

Chinook salmon begin their lives as eggs in cold, clear gravel-bottomed streams. After a few months they hatch into alevin—2.5 to 5 cm fish with large yolk sacs attached to their bellies. The yolk sac provides nutrition as the alevin grows, and once it is absorbed, the alevin is considered a fry, resembling a small salmon. The fry stage progresses to the parr stage, when eponymous dark “parr marks” appear along the fish’s sides.

Some Chinook salmon fry then head to the ocean and undergo smoltification, the next stage in their life cycle. As smolts they take on a silvery, metallic sheen. Some parr stay behind—most notably those in Alaska—spending about a year in freshwater before swimming downstream to the ocean.

Once in the ocean, Chinook salmon remain there for a few years, schooling and feeding on the abundance the sea provides. Their prey includes smaller fish such as herring and smelt, as well invertebrates like shrimp and large plankton. Prey availability fluctuates annually with changes in weather, tides, and climate. Recently, Chinook salmon have relied heavily on anchovies—a plentiful but thiamine-poor (vitamin B1) food source. This dietary shift has created problems when the salmon return to their natal streams to spawn, as the vitamin deficiency is passed on to their offspring.

Vitamin B1 is essential for fry, supporting healthy growth and neurological function. Hatchery studies of fry from wild Chinook salmon have shown that about 20% can die from vitamin B1 deficiency. The severity of the problem appears to vary among salmon populations depending on the river they return to. This is still an early emerging concern, but early research has highlighted the risks (see the open access study from California that documented the impacts of vitamin B deficiency on offspring survival: https://www.pnas.org/doi/10.1073/pnas.2426011122).

Chinook salmon are considered federally endangered due to a combination of threats, including climate change, dams, and habitat loss. At present, several petitions have been submitted to the U.S. Fish and Wildlife Service (USFWS) to extend endangered or threatened status to additional populations. Listing distinct groups—such as the Gulf of Alaska Chinook salmon—helps direct conservation efforts toward the populations facing the greatest risks. Upcoming decisions will be critical: USFWS is scheduled to rule by November 3 for Oregon and Northern California Chinook salmon, and by January 2 for Washington coast spring-run salmon.

References and further reading:

Alaska Department of Fish and Game. n.d. Chinook salmon. https://www.adfg.alaska.gov/index.cfm?adfg=chinook.main

Columbia River Inter-Tribal Fish Commission. n.d. We are all salmon people. https://critfc.org/salmon-culture/we-are-all-salmon-people/

Fuller, P., G. Jacobs, M. Cannister, J. Larson, and A. Fusaro. 2025. Oncorhynchus tshawytscha (Walbaum in Artedi, 1792): U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?speciesID=920, Revision Date: 7/5/2025, 12/20/2019, Peer Review Date: 6/26/2014.

Mantua, N.J., et al. 2025. Widespread thiamine deficiency in California salmon linked to an anchovy-dominated marine prey base. PNAS 122(26): e2426011122. https://doi.org/10.1073/pnas.2426011122.

Oregon Department of Fish & Wildlife. n.d. Chinook salmon. https://myodfw.com/fishing/species/chinook-salmon.

Walford, L.A. 1937. Marine game fishes of the Pacific Coast from Alaska to the Equator. University of California Press, Berkeley. 205 pp.