Gulf Islands National Park Reserve of Canada

The Lyall Creek Story

The Salmon Species of Lyall Creek

Coastal Cutthroat Trout | Chum | Coho

Coastal Cutthroat Trout

( Oncorhynchus clarkia clarkii )

Coastal cutthroat trout are highly variable in life history traits and range from northern California to Prince William Sound in Alaska. The anadromous form has a maximum size of 65-70 cm and 3 kg with a short, conical head, a pointed to rounded snout and a rather large mouth with well-developed teeth on both jaws.

The adult coastal cutthroat trout is dark to olive-green with numerous black spots and silvery sides. Its most distinguishing feature is the red-orange slash on the lower jaw. The sea-run form occurs wherever there is access to seawater (along the pacific coast).

Like most salmon, the adult cutthroat returns to its natal stream in late autumn and early winter. Unlike many salmon species, however, the coastal cutthroat trout is a repeat spawner and may return for many years. Spawning takes place in February to May, in small, low gradient , gravelly streams. The female turns onto her side and flaps her tail up and down to create a depression called a redd in the gravel of the riverbed. After the female finishes preparing the redd, she will lay between 1100 and 1700 eggs while the male fish releases sperm (milt) to fertilize the eggs. Hatching occurs 6-7 weeks later. The juvenile cutthroat may stay in fresh water from 2-4 years. Adults in the marine environment tend to stay close to their natal streams in shallow coastal waters.

Chum

( Oncorhynchus keta )

Chum salmon are steel-blue along the back, with speckles of black, silver on the sides with a silvery to white belly. Males have tinges of black on the tips of the caudal , anal and pectoral fins. Spawning males have dark olive to black bars dorsally and grey-red with green vertical bars on the sides; anal and pelvic fins with white tips. Spawning females resemble spawning males but less distinctly marked. Individuals range in size from 43 to 97 cm, with a weight of 4 to 5 kg.

Chum salmon have evolved to migrate immediately to marine waters shortly after hatching. This strategy is a trade-off reducing mortality associated with the freshwater environment but increasing dependence on estuarine and marine habitats.

Chum return from the sea to coastal streams in late fall, as creek water levels rise, and deposit their eggs in the stream gravel during November and December. A female chum might lay up to 30,000 eggs. Adult chum die after spawning while the chum embryos develop within the eggs and hatch after approximately 8 weeks. At this time the young fish are called alevins and they continue to reside in the gravel. After about 10 — 12 weeks, the alevins emerge as fry.

When the fry emerge, they immediately begin their downstream migration to marine waters. During the freshwater stage of their life cycle, chum feed on aquatic insects. Migrating fry form schools in the estuary, remain close to the shore for a few months to avoid predators, and then move to deeper open ocean waters by mid to late summer. At this time they are approximately 10 — 16 cm long. Some juvenile chum will remain in nearshore marine waters until late in their second year before migrating to the open ocean. As early as the third year of their life, chum will begin their migration back to their spawning ground.

Coho

( Oncorhynchus kisutch )

Coho are characterized by the presence of small black spots on their backs and on the upper lobe of their caudal fins. In the sea they are dark-metallic blue or greenish on the back and upper sides, silver on the middle and lower sides, and white below. When coho are spawning, the head and back turn dark to bright green, and the sides become bright red. Coho have small black spots on their back and upper sides. Coho usually weigh 3 — 6 kg and are 60 — 76 cm long.

Similar to chum salmon, coho return to coastal streams in the late fall and winter to spawn. Unlike the chum, after emergence in the spring, juvenile coho usually live in fresh water for 1-2 years (sometimes up to 4 years) to take advantage of productive coastal streams for their initial growth.

Juvenile coho in freshwater streams feed mainly on insects and stay almost entirely in pools. They develop strong territorial behaviour. When these fish return to the sea they are known as smolts. Upon reaching the sea, coho remain inshore for a time, feeding on planktonic crustaceans. As they grow larger, coho will move farther out and feed on larger organisms. Time at sea varies. Some males (called jacks) mature and return after only 6 months at sea at a length of about 12 inches, while most fish stay at least 18 months before returning as full size adults. Coho salmon ordinarily return in their third year to their natal stream (where they were hatched) to spawn and die.

Background of Lyall Creek
Anatomy of a Creek
Restoring the Habitat of Lyall Creek
Baseline Inventory and Monitoring

Related Links:

Fisheries and Oceans Canada's Page on Pacific Salmon