ECOLOGICAL DATA
Distribution: spawn in medium to large streams and
larger rivers; extensive feeding migration in Pacific Ocean.
Habitat: spawn in Jul-Nov in Fraser River, Aug-Sep in south, Oct on Vancouver
Is. and in Sep in north; eggs laid in redds in gravel; fry emerge in Mar-May; three life
history strategies exist: "immediate" fry migrate directly to estuary,
"ocean-type" rear in freshwater for 60-120 days before migrating seaward as
smolts, and "stream-type" fry rear in river for 1-2 yr and migrate seaward as
smolts; fry (33-45 mm) utilize shallow, nearshore from May-Aug/Sep, e.g. tidal
channels, tide flats and eelgrass beds; rear in deeper water as they grow until late
summer; smolts (8-10 cm) migrate to estuary in Jul; rear in outer estuary or deeper
nearshore water until fall; juveniles migrate to ocean and spend 2-4 yr feeding; some
remain in inshore waters.
Tidal elevation: fry feed with tide cycle, at high tide line and in tidal
channels at ebb tide; smolts and adults feed and migrate in deeper water.
Food: fry prey on insects, amphipods, decapod larvae and calanoid copepods;
juveniles eat small fish (herring, sand lance, rockfish), crustaceans (amphipods,
euphausiids, cladocerans); adults eat fish and euphausiids.
Predators: fishes, birds, marine mammals and bears.
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GROWTH RATE
Largest of Pacific salmon; mature at 3-5 yr; maximum size 147
cm and 57 kg.
FISHERY
Support valuable commercial, sport and native fisheries; 1986
commercial catch was 4420 t valued at almost $19.7 million.
REFERENCES
Fraser, F.J., P.J. Starr, and A.Y Fedorenko. 1982. A review of
the chinook and coho salmon of the Fraser River. Can. Tech. Rep. Fish. Aquat. Sci. 1126:
130 p.
Healey, 1980. Utilization of the Nanaimo River estuary by juvenile chinook salmon, Oncorhynchus
tshawytscha. Fish. Bull. 77: 653-668.
Levy, D.A., and T.G. Northcote. 1979. Juvenile salmon utilization of tidal channels in
the Fraser River estuary, British Columbia. Univ. B.C. Westwater Res. Cen. Tech. Rep. 23:
70 p.
Levings, C.D. 1982. Short term use of a low tide refuge in a sandflat by juvenile
chinook, Oncorhynchus tshawytscha, Fraser River estuary. Can. Tech. Rep. Fish.
Aquat. Sci. 1111: 33 p.
Levings, C.D. McAllister, and B.D. Chang. 1986. Differential use of the Campbell River
estuary, British Columbia, by wild and hatchery-reared juvenile chinook salmon (Oncorhynchus
tshawytscha). Can. J. Fish. Aquat. Sci. 43: 1386-1397.
Simenstad, C.A. 1983. The ecology of estuarine channels of the Pacific Northwest
coast: a community profile. U.S. Fish Wildl. Serv. FWS/OBS-83/05: 81 p.
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