Coastal Cutthroat Trout

Kw’sí:ts

Oncorhynchus clarkii clarkii

Identification Tips:

• Widely variable colouration and marking patterns
• Very similar to Rainbow Trout at all life stages
• Upper jaw long; extends behind eye when mouth is closed (Rainbow does not)
• Usually has red (rarely yellow) 'cut' marks on underside of gill covers

• Black spots on dorsal fin (Pacific Salmon species have none as juveniles)

Conservation Status:

British Columbia	Canada		Natureserve
	COSEWIC	Species at Risk Act
Blue List	Not Assessed	None	G4T4, S3S4

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

Life History:

• Spawn in later winter/early spring; usually peaks in February
• Three general life history types; Resident, Freshwater Migratory and Sea Run
• Many variations of these types within and among populations
• Unlike Pacific Salmon, Cutthroat and Rainbow Trout may spawn in more than one year.

Resident
• May mature at very small size; 15 cm in some populations
• Rarely live longer than 5 years
• Some populations in coastal BC are isolated above waterfalls (colonized stream when sea level higher)

Migratory
• Move between freshwater habitats including streams, large rivers, and lakes.
• Typically larger body size (to 60 cm in some lakes); may live to 10 years

Sea Run
• Spend one to 3 (rarely 4) summers in freshwater before migrating to sea at 25-30 cm in length
• Typically at sea for summer months and in freshwater over winter
• Most mature at age 4.
• Arrive in spawning streams between August and April to spawn in spring.

Smaller juveniles and residents eat zooplankton and aquatic invertebrates
Larger migratory and sea run individuals also consume fish

Habitat:

• Require cool-water (<18 C) • Most spawn in gravels of small, low gradient coastal streams; often <1 m wide • Rearing and foraging habitat is highly variable. • In streams highest densities are in low gradient reaches with extensive pools, gravel substrate and abundant large woody debris • Commonly use off channel habitats of small streams for overwintering

Range:

British Columbia
• Entire BC coast including most coastal islands.
• Rarely more than 200 km inland on South coast (Hope, in Fraser system)
• Introduced into Kootenay and Lower Arrow Lakes

Global
• Coastal drainages from Northern California to Prince William Sound, Alaska

Comments:

• Over 600 sea run stocks in BC
• At least 15 extirpated and 14 at risk in Lower Mainland and Southern Vancouver Island
• Coho stocked in streams tends to displace wild Cutthroat fry and juveniles from preferred habitats

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