Coho Salmon, also know as the silver salmon can be distinguished by the fine dark spots on the back and upper lobe of the tail fin, the long anal fin and gray gums. Coho feed primarily on alewives, smelt, and other small fish. Adult Coho spawn during the fall in riffle areas of streams in reds (nests of gravel) which the females construct.
After spawning is completed they die. Normally, Coho have a three year life cycle; however, a few males will return to spawn at two years of age and are known as “jacks”. Occasionally some Coho may live to the age of four; these fish are the 20 pound Coho that are caught infrequently in Lake Michigan. The average mature fall Coho salmon will weigh 5 to 10 pounds before spawning.
Up to 75% of the salmonoids caught annually in the Illinois portion of Lake Michigan are Coho salmon. Because this species dies after spawning and the recruitment from stream spawning is very limited, an annual stocking program is necessary. In Illinois Coho are reared in an accelerated fashion and in 6 months are stocked as 5-6 inch long fish in the spring. Due to the lack of clean, cool streams salmon do not reproduce in Illinois.
Trolling offshore in April, May and June is most productive when using spoons, plugs, spinners and flies and squids preceded by dodgers. Even whole alewife and smelt can be successful when trolled. Coho prefer temperatures in the mid-50s F. and generally are found nearer the surface than Chinook. After 60 degrees F. Coho tend to go deeper to find their preferred water temperature. Coho may be found in water temperatures from 45 to 60 degrees F., with a peak feeding temperature at 54 degrees F.
Chinook Salmon are also known as the king salmon. It is distinguished by dark spotting on the back and usually on both lobes of the tail, a long anal fin and teeth set in black gums. Chinook feed primarily on fish such as alewives and smelt. Most Chinook have a four-year life span. Mature Chinook spawn similarly to Coho salmon, then die. A portion of a year class of Chinooks may return before the normal four years to spawn.
Some Chinook may live longer than 4 years and reach 40 pounds or more. The elusive Chinook is typically found in deep water except when it starts its fall spawning run into rivers and/or harbors. For this reason the bank fishermen’s catch of the Chinook is restricted to early fall, casting with lures and snagging during the latter fall period (check local and state snagging regulations).
The Chinook run usually peaks before the Coho run. The Chinook fishery is maintained by annual stocking because it does not reproduce in adequate numbers in Lake Michigan tributaries. Chinook spend about 6 months in the hatchery until they are stocked as 2-3 inch long fingerlings each spring. Chinook tend to prefer warm temperatures in the mid-50s and seem to be more light sensitive and harder to catch than coho. Chinook are active in water temperatures from 45 to 60 degrees F. with a peak feeding temperature at 54 degrees F.
The Rainbow Trout is distinguished by its white mouth, black spots and entire tail and its 12 or fewer anal fin rays. The rainbow and the steelhead are the same species, differing only in spawning behavior. The rainbow spends its entire life in streams, whereas the steelhead is anadromous in that it migrates to a stream to spawn after living in the ocean or a large lake. Rainbow trout feed on insects and fish. Many spawn in early spring with eggs laid in gravel at the head of a riffle area, but some are fall spawners. Rainbow trout as well as other trout do not normally die after spawning, like salmon (coho and chinook )
Rainbow prefer water temperatures of 55-60 degrees F. They are known as great migrators or wanderers. Some rainbow reach a hefty 16 pounds at age six, although the average rainbow caught weighs about five pounds. The largest caught to date in Illinois weighed 24 pounds and 13 ounces. May, June, July and August are the best months for fishing for rainbow.
The most distinguishing characteristics of the Brown Trout include large black and sometimes reddish-orange spots with a pale border on the sides of the fish. These spots are modified when the fish is large. The food of the adult brown includes terrestrial and aquatic insects, worms, crayfish and fish. Brown trout spawn in late autumn at the gravelly headwaters of streams.
They grow rapidly and may live to an age of six years and reach weights of eight to ten pounds. Some may reach 30 pounds in Lake Michigan. Brown trout prefer water temperatures between 55 degrees and 65 degrees F. and are typically found in near shore waters. This wary fish can be taken more readily in early morning and twilight hours. Light line is in order using conventional lures or natural baits. Shore fishing methods are similar to the rainbow trout.
The Lake Trout also known as laker, can be distinguished by its white mouth, irregular whitish spots on the back and sides, deeply forked tail and a white leading edge on the lower fins. The diet of adult lake trout consists of fish, insects and small invertebrates. Sexually mature adults weight 6 to 7 pounds at about 6 years of age.
Lake trout may live 20 years or longer and attain weights of 30 pounds or more. They are usually found on the bottom between depths of 90 to 250 feet, but may be found at lesser depths when the water temperature is near 48 degrees F. Generally, lake trout are caught only from boats in Illinois.
The lake trout in Lake Michigan have been maintained by an annual stocking program since 1965 by the U.S. Fish and Wildlife Service, with hopes of reestablishing a naturally reproducing population. During the spring months, lake trout can be taken in the upper layers of warmer water, but as the season progresses and water temperatures go above 48 degrees F., lake trout are normally taken near the bottom. During the summer months (July-September) they tend to stay near the bottom where temperatures are between 45 and 50 degrees F.
During the fall months mature lake trout move into shallow waters and reef areas in search of spawning areas. Shiny metal spoons are successful lake trout lures when fished properly. Certain salmon lures and flies in combination with a dodger also are effective. Lake trout feed on alewives, smelt, chubs and sculpins.