ECOLOGICAL DATA
Distribution: spawn in lake fed systems; extensive
feeding migration in NE Pacific Ocean.
Habitat: mature adults enter natal river from Jun to Sep; spawn in Sep and Oct
in gravel areas of lake tributaries, outlet, or spring-fed areas along shore; fry emerge
in Apr and May and rear in lake for 1-2 yr; some stocks migrate as fry to rear in riverine
or estuarine nursery areas; juveniles from lakes emigrate during Apr and May as smolts at
60-100 mm; May and Jun juveniles rear along Vancouver Is. and Gulf Is., and leave Georgia
Strait by Jul; some fry rear in upper estuary over spring and summer until 60-70 mm, then
enter Fraser plume in July and disperse from Strait by Sep-Oct; feed for 2-3 yr in ocean
before returning to natal river/lake to spawn; may hold off mouth of river for up to
several days or weeks before moving upstream to spawn.
Tidal elevation: some fry rear in shallow areas in estuaries; smolts and adults
feed and migrate in deeper water.
Food: insects, copepods, euphausiids, fish larvae, amphipods, decapod larvae,
and crustaceans, squid and small fishes offshore.
Predators: fishes, birds, marine mammals and bears.
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GROWTH RATE
Fry grow from 35 mm on entrance to delta to 90-110 mm by Sep in
Georgia Strait; reach sexual maturity at 4-5 yr and may live as long as 8 yr.
FISHERY
Most important species for commercial and Native fisheries;
1986 commercial catch was 29,811 t valued at $143.3 million; also support sport fishery.
REFERENCES
Birtwell, I.K., M.D. Nassichuk, and H. Beune. 1987.
Underyearling sockeye salmon (Oncorhynchus nerka) in the estuary of the Fraser
River, p. 25-35. In H.D. Smith, L. Margolis, and C.C. Wood. [ed.] Sockeye salmon (Oncorhynchus
nerka) population biology and future management. Can. Spec. Publ. Fish. Aquat. Sci.
96.
Foerster, R.E. 1968. The sockeye salmon, Oncorhynchus nerka. Fish. Res. Board
Can. Bull. 162: 422 p.
Healey, M.C. 1980. The ecology of juvenile salmon in Georgia Strait, British Columbia,
p. 203-229. In W.J. McNiel and D.C. Himsworth [ed.] Salmonid ecosystems of the
North Pacific. Ore. State Univ. Press, Corvallis.
Healey, M.C. 1982. Juvenile Pacific salmon in estuaries: the life support system, p.
315-341. In V.S. Kennedy [ed.] Estuarine comparisons. Academic Press, N.Y.
Manzer, J.I. 1956. Distribution and movement of young Pacific salmon during early
ocean residence. Fish. Res. Board Can. Pac. Progr. Rep. 106: 24-28.
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