Oncorhynchus tshawytscha

Identification Tips:

Adults
• Silver coloured at sea; darker brown or olive or reddish in freshwater
• Irregular black spots on back and on top and bottom lobes of caudal (tail) fin (on bottom lobe only in Coho)
• Gums at base of lower jaw teeth are black in Chinook (white in Coho)

Juveniles
• Difficult to distinguish from Coho Salmon
• Anal fin rays all the similar in length in Chinook (front rays longer than rest in Coho)
• First ray of dorsal fin is dark in Chinook (white in Coho)
• First ray of anal fin is clear in Chinook (white in Coho)

Conservation Status:

British ColumbiaCanadaNatureserve
COSEWICSpecies at Risk Act
Not at Risk (Yellow List)Not AssessedNoneG5, S4

Information Source: BC Conservation Data Centre: http://a100.gov.bc.ca/pub/eswp/

Life History:

• Spawn in fall at 2-7 years of age (most 3-5)
• Some males return as small, mature 'Jacks' after 6 months at sea
• Two life history types; Stream-type and Ocean-type
• Stream-type spend 1 to 3 years in freshwater, perform extensive offshore ocean migrations, and return to rivers in spring or summer for several months prior to spawning
• Ocean-type migrates to see within months of emerging from gravel, stay in coastal areas and migrate to to spawning rivers immediately before spawning.

Habitat:

• Often spawn in larger streams and over coarser gravel than other salmon but may use small streams

Stream-type
• Juveniles rear in main rivers, large tributaries and sometimes lakes
• May overwinter in off-channel ponds or in slow moving water close to cover
• Migrate to estuaries after 1 year and are found near shore until mid-summer, when they move offshore
• Adults hold in deep pools in rivers over the summer prior to spawning

Ocean-type
• Rear in estuaries close along marsh edge at high tide and in small tidal channels at low tide

Range:

British Columbia
• Found in most medium to large rivers along the coast
• May ascend hundreds of km to spawn.
• Many rivers contain more than one run (population)

Global
• Northeaster Asia, including northern Japan
• Northern Alaska south to central California

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Primary Information Source:
McPhail, J.D. 2007. The Freshwater Fishes of British Columbia. University of Alberta Press. Edmonton, Alberta.