Ontario-Great Lakes Area Fact Sheets

Coho Salmon

General Description

The coho salmon is a pacific salmon and has the following characteristics:

• the body is fusiform, streamlined, somewhat laterally compressed;
• the snout becomes extended, narrow, and turned down at the tip in breeding males;
• the mouth is greatly deformed in breeding males, with the lower jaw enlarged and turned up at the tip so that the mouth is unable to close;
• the body colour of marine or Great Lakes adults is steel blue to slightly green on the back, brilliant silver on the sides, white on the underside, and small black spots on the back and sides above the lateral line and upper lobe of the caudal fin;
• breeding males become darker on the head and back, the sides are dull with a brilliant red stripe, and the underside is grey to black;
• the colour of females changes little and colour changes in Great Lakes males are less spectacular.

Distribution

The coho salmon occurs naturally only in the Pacific Ocean and its tributary drainage. In Canada, it is found in all the Great Lakes, in Alberta, in the Porcupine River system in the Yukon Territory, as well as its native range in British Columbia.

Habitat and Life History

The coho salmon is a cold-water species that spends about 18 months in the sea or lake and returns to streams to spawn in the fall, usually at age 3 or 4 years. Adults move upstream during the day and usually do not travel more than 240 km (150 miles) in larger rivers. Spawning takes place in swifter water of shallow, gravelly areas of river tributaries from October to November or November to January in North America. The female prepares the redd (nest) in medium to small gravel by lying on her side and beating vigorously with her tail. The eggs fall into spaces between the gravel and immediately the female begins digging at the upstream edge of the nest covering the eggs with the displaced gravel. The female guards the nest as long as she can, but the adults die shortly after spawning. The eggs hatch in the spring, and because of the spread in spawning time, fry emergence occurs from early March to late July. Some fry migrate almost immediately to the sea or lake but most remain at least 1 year in freshwater or lake tributaries. Usually in March or April of the year following their emergence, the young coho salmon (smolts) begin to migrate to the ocean or lake. They migrate mainly at night in small schools. For the first few months after migration to the sea or lake, they remain close to shore and then move out to the open water.

Food Habits

The food of the marine adult coho is more varied than that of many pacific salmon and consists mostly of fish and invertebrates. In the Great Lakes, the bulk of the food of larger coho consists of rainbow smelt and alewifes.

Economic Importance

The coho salmon has been of considerable importance as a commercial fish and as a sport fish in British Columbia. There has been a surge of interest in this species since it was introduced into the Great Lakes in the 1960s.

The coho salmon is an excellent food fish, which is marketed canned, fresh or frozen.

Fishing Facts

The coho salmon hybridizes in nature with the chinook salmon.

Further Information

For further information, please contact your local DFO office: http://www.dfo-mpo.gc.ca/oceans-habitat/habitat/aboutus-apropos/regions/arctic-arctique_e.asp?#1