Chum Salmon

Chum Salmon or Dog Salmon (Oncorhynchus keta)

Identification:

Juveniles: Faint parr marks, extend little if any below the lateral line. Back mottled green, sides silvery with a faint green iridescence below mid-line. No spots on fins.

Adults: Dorsal surface is metallic blue with a black tinge on the tips of the pectoral, anal, and caudal fins. No distinct black spots on back or fins, but occasionally fine speckling. Length about 25 inches.

Spawning adults: Males dark above and dusky on the ventral surface. The sides are dirty red or purple with distinct greenish bars or mottling. The upper jaw forms an elongate hooked snout. Females have similar coloration but the red is less pronounced. Also, broad dark purple or purple-red horizontal stripes along either side of the body.

Life History: All anadromous. Maturing adults return to their home streams between July and January depending on the region. Spawning usually occurs from June to early September, but can extend to late December. The female selects the redd site, an area with a gravelly substrate, and usually immediately above turbulent areas or where there is upwelling. She then digs the nest(s) and deposits her eggs which are simultaneously fertilized by the male. Fecundity ranges from 2100-3700 eggs per female. Both females and males die after spawning is completed. After emergence, the fry quickly migrate downstream to estuarine waters where they reside until entering the ocean. The timing for this varies from early spring to midsummer. The adults then spend two to seven years in the ocean before returning to their home streams to spawn.

Feeding: While in fresh water, the juveniles feed mainly on insects such as chironomid larvae, also copepods and nematodes. Ocean fish feed on diatoms, arthropods, insects, fish larvae, other fishes, pteropods and squid.

References:

Groot, C and Margolis, L. Eds. 1991. Pacific Salmon Life Histories. UBC Press. Vancouver, B.C.

Juvenile fish id key. 1995. The Streamkeepers Handbook: a Practical Guide to Stream and Wetland Care. Community Involvement Division, Salmonid Enhancement Program, Department of Fisheries and Oceans. Vancouver, B.C.

Scott, W and Crossman, E. 1973. Freshwater Fishes of Canada. Fisheries Research Board of Canada. Bulletin 184. Ottawa, Ontario.