Lake trout

Description

Size

• Because lake trout are long-lived and can reach 20 to 25 years of age, the larger ones can exceed 10 kilograms (22 pounds) in weight.

Appearance

• Lake trout are the least colourful of trout. They are grey fish with irregular white spots.
• During the fall spawning season, the fins near the tail become a pale orange.
• Caudal fin is forked.

Natural History

Habitat

• Lake trout are native to many of Alberta's deep cold lakes.
• Lake trout feed near the surface of a lake when the water is cold (spring and fall).
• During the summer, the cold denser water sinks to the bottom of the lake and the trout follow it down.

Food

• Young lake trout feed on freshwater shrimp and other aquatic invertebrates.
• Larger lake trout eat other species of fish, mostly whitefish and cisco (tullibee)

Reproduction and Growth

Growth Process

• Lake trout grow very slowly, and often don't mature until they are 8 to 10 years of age.

Conservation and Management

Status

Lake trout are classified as Sensitive in the General Status of Alberta Wild Species report. See:

• General Status of Alberta Wild Species

Issues

• Species somewhat limited by the small number of deep, cold lakes in Alberta.
• Because of this late age of spawning, heavy fishing pressure can seriously deplete lake trout populations. As the main threat to populations is over-harvest, angling is now regulated.

Current management

Fish Sustainability Index

Alberta's lake trout populations have been assessed under the Fish Sustainability Index, see:

• Lake Trout: Boreal FSI
• Lake Trout: Mountain FSI

Fishing

Lake trout are cold-water game fish subject to current Alberta sportfishing regulations. For details, see the My Wild Alberta website at:

• Fishing