ECOLOGICAL DATA
Distribution: spawn in coastal streams and larger rivers
(e.g. Fraser and Skeena); extensive feeding migration in Pacific Ocean.
Habitat: mature adults spawn from Sep-Jan in south and as early as Jul in
north; eggs laid in gravel redds in lower reaches of streams, or up to 100 km from mouth
in larger rivers; fry emerge from gravel in April and May and swim directly to estuary;
form schools and disperse along shore rearing in shallow, near-shore nursery areas;
utilize eelgrass beds, estuarine marshes and tidal channels; move to deeper water as they
grow; late-Jun & early-Jul begin to migrate to ocean (80-100 mm); spend 2-3 summers in
ocean; on return, may pause at mouth of spawning river for several days or weeks depending
on river discharge before migrating upstream.
Tidal elevation: fry rear in shallow nursery areas; smolts and adults feed and
migrate in deeper water.
Food: fry feed on harpacticoid copepods, decapod larvae, insects and amphipods
in nursery areas; in outer estuary feed on cladocerans, decapod larvae, Oikopleura
and gammarid amphipods; amphipods and euphausiids during ocean migration.
Predators: fishes, birds, marine mammals and bears.
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GROWTH RATE
Mature at 3-4 yr; fry, 36 mm in May leave for ocean at 12-25 cm
in Sep; maximum size is 102 cm.
FISHERY
Support important commercial and native fisheries; 1986
commercial catch was 24,922 t valued at $37.6 million.
REFERENCES
Healey, M.C. 1979. Detritus and juvenile salmon production in
the Nanaimo estuary: I. Production and feeding rates of juvenile chum salmon (Oncorhynchus
keta). J. Fish. Res. Board Can. 36: 488-496.
Healey, M.C. 1980. The ecology of juvenile salmon in Georgia Strait, British
Columbia., p. 203-229. In W.J. McNeil 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.
Mason, J.C. 1974. Behavioural ecology of chum salmon fry (Oncorhynchus keta) in
a small estuary. J. Fish. Res. Board Can. 31: 83-92.
Neave, F. 1966. Salmon of the north Pacific Ocean - Part III. A review of the life
history of north Pacific salmon. 6. Chum salmon in British Columbia. Int. North Pac. Fish.
Comm. Bull. 18: 81-85.
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