Chinook Salmon, Oncorhynchus tshawytscha
Identifying characteristics: (Non-Native Fish) Two dorsal fins including one adipose fin, inside the mouth and gums, black, small spots on upper back and tail, 15 – 17 rays in anal fin.
The salmon family, or Salmonidae, includes the salmon, trout, and whitefishes. All are characterized by adipose fin, and have a preference for cold water with a high oxygen content, making the Great Lakes an ideal habitat.
The chinook is a fairly new variety of salmon introduced into the Great Lakes in the 1870s. Sometimes called “King Salmon”, these fish did not reproduce successfully and eventually disappeared. In 1966, Great Lakes states Michigan, New York and Wisconsin, with the help of the province of Ontario reintroduced the Chinook. Great Lakes populations of Chinook are maintained by annual stream stocking programs
Chinook live in Great Lakes shoals or near-shoal waters (less than 100 foot depth(s)) as a rule. In the fall they move into the southern reaches of each of the great lakes., traveling 5-15 miles offshore as they go. In the spring they retrace their route and by the following fall, they congregate at the stream they began their journey at and begin their spawning runs upriver.
Chinook spawn in streams over beds of large gravel, near riffles. Within two weeks after spawning, adult chinook die. Chinook compete with other salmon and trout for scarce spawning grounds. The following spring the eggs hatch, and the young usually remain in the river for one year before they migrate down to the lake.
Once in the lake, males tend to remain for 1-2 years and females for 3-4 years. The King Salmon average a weight of 30 to 40 pounds and 38 inches in length.
Young chinook in rivers eat insects, insect larvae and crustaceans; adults in the lakes eat fish almost exclusively. In the Great Lakes, smelt and alewives make up their main diet.
Predators include rainbow trout, coho salmon smolts and fish-eating birds. The young also compete with trout and other salmon for food.
Anglers prize chinook partly because of their large size and the challenge they present for fishing, and partly because they make a delicious meal. While other pacific salmon species have red flesh, chinook meat is often white.