Pacific Cuttrout Trout

Cutthrout Trout: Onchorynchus clarkii clarkii spp.

Species: Coastal Cut-throat Trout – Onchorynchus clarkii clarkii spp.
B.C. Status: Blue

Key Information:

Coastal cutthroat trout are a subspecies of the cutthroat trout. All cutthroat trout are the same genus as Pacific Salmon. They too are salmonids although they have a different spawning and life cycle from salmon. Cutthroat trout stay close to the shore and do not necessarily “run” as do the salmon.

There are two varieties of the coastal cutthroat trout, resident (freshwater) and sea-run. Depending on the circumstances, some coastal cutthroat will swim their way to the ocean to spend part of their life in the salty waters, while others will begin and complete their lifecycle in freshwater bodies. Other than the salinity, both varieties of coastal cutthroat have the same habitat requirements.

For a healthy coastal cutthroat population, clean and clear water with plenty of oxygen is essential. Coastal cutthroat trout are sensitive fish and wherever they are found, they indicate a healthy ecosystem. As sensitive fish, they need vegetation around the bodies of water in which they live. Vegetation provides shelter from the sun, habitat for their prey (insects, invertebrates and small fish) and also prevents streamside erosion.

Pools created by large debris and/or natural pools such as lagoons also create shelter for the coastal cutthroat trout to live.

Stream flow is very important for these fish during their early development. They require a consistent and specific water flow (velocity). Too strong of a flow may degrade the channel and can wash away young fish to the sea too early, while too slow a flow can increase competition with other fish.

The spawning cycle of the coastal cutthroat trout is different than that of other salmonids. They can spawn repeatedly (they do not die after spawning) between December and May, so long as they have a suitable nesting spot with clean gravel and water. The eggs are laid in the gravel, and after about 7 weeks emerge as little fry. For two to five years they remain in the freshwater body in which they are reared. Once they have matured into smolts they begin their migration to other bodies of water, be it ocean or fresh water. After about a year, they return to spawn.

Coastal cutthroat trout are very important to our aquatic ecosystems, they help balance and connect the coastal and freshwater food web, they are both predator and prey. They feed and nourish many predator species including great blue herons, bears, river otters, osprey, mink, adult salmon, seals and humans!

The coastal cutthroat trout is a species of special concern. A decline in their population is indicative of a change in their habitat. Pollution, degraded water quality, change in water flow, erosion, excess sediment, etc. are all of concern. As sensitive fish, there are many activities in which humans can contribute to changes in their population, both positively and negatively.

Identification – what to look for?

• Sleek fish with blueish-green backs
• Silver sides
• Many spots
• Reddish/orange under jaw
• Jaw is long and extends further than their eyes
• Can grow as big as 10–18 inches and older fish can be over 20 inches in healthy ecosystems

Where are they found?

• Along the coast, close to the shore in estuaries, lagoons and in freshwater streams, lakes and beaver ponds
• Around the aquatic vegetation in water bodies with insects
• They love little hiding spaces and shelter from the sun, so can be found around logs and fallen debris and vegetation in water
• In year-round water flow, which isn’t too fast, nor too slow
• Sea-run coastal cutthroat love shelter in lagoons and estuary pools, typically among the eelgrass
• On Cortes Island, they are found in Hague and Gunflint Lakes

Cool facts!

• It is believed that all subspecies of cutthroat trout (freshwater fish) evolved from the coastal cutthroat trout species (marine fish)
• Sea-run and resident cutthroat trout can successfully reproduce together as they may end up in the same breeding spot
• Typically both the sea-run and the resident cutthroat trout stay within 50 miles of the stream in which they hatched in
• Coastal cutthroat trout do not die after they spawn, in fact it is believed that they may skip a year of spawning
• The amount of eggs laid depends on the size of the fish, anywhere from 100 to 600 eggs
• Some resident cutthroat trout can live for over 15 years! Sea-run can live for around 10 years

Useful links:

Government of Alaska (PDF)
South Coast Conservation Program