Summer Journey 



The FISHES 



Coko Salmon 



of LAKE MICHIGAN 



"The Fishes of Lake Michigan" is the Museum's Sum- 

 mer Journey for children during June, July and August. On 

 a self-guided tour, youngsters will be introduced to some 

 of the different fishes foimd in the lake, with an emphasis 

 on the changes in the abundance and species composition 

 of the fish populations. 



There have been many changes in the fish life of Lake 

 Michigan in the last century. The Lake Sturgeon (Aci- 

 penser fulvescens), once abundant in the lake, is now rare, 

 while other fishes have been introduced into Lake Michigan, 

 either by accident or deliberately. 



about 1921 . Gradually moving into the other Great Lakes, 

 it appeared for the first time in Lake Michigan in 1936. 

 Since that time it has practically wiped out the Lake Trout 

 {Salvelinus namaycush), once the foundation of the lake's 

 commercial fishing industry. 



About this time, when the Lake Trout and other fishes 

 were decreasing in number, the Alewife {Alosa pseudoha- 

 rengus) moved into the lake. This fish is also found along 

 the Atlantic Coast and since 1873 has been in Lake Ontario, 

 where it was probably stocked by accident. Using the 

 Welland Canal route, it moved into Lake Erie about 1931 



Carp (Oyrpinus carpio) were introduced into the lake 

 before the turn of the century, flourished, and have provided 

 commercial fisherman with catches as high as 7,000,000 

 poimds in one year. Goldfish {Carassius auratus) first es- 

 caped into the lake from lagoons where they were stocked 

 for the 1893 Columbian Exposition. They were introduced 

 many times later by fishermen and by people who simply 

 released their pet fish in the lake. 



American Smelt (Osmerus mordax) eggs were planted in 

 Crystal Lake, Michigan, in 1912. These hatched and the 

 fish lived and spawned in that lake, escaping through an 

 outlet into Lake Michigan about 1923. 



Rainbow Trout {Salmo gardneri) were stocked in the 

 lake and streams of northern Wisconsin and Michigan that 

 empty into the lake. This fish is also called the Steelhead. 

 Other fishes extended their ranges and invaded Lake Mich- 

 igan from the lower Great Lakes and the Atlantic Ocean. 

 In the past, Niagara Falls was a natural barrier between 

 Lakes Ontario and Erie. Construction of the Welland Canal, 

 completed in 1829 and enlarged about 80-90 years later, 

 allowed ships from Lake Ontario to pass into Lake Erie. 

 Fishes also used this canal for passage between the lakes. 



The Sea Lamprey {Petromyzon marmus) lived along the 

 Atlantic Coast and was also found in Lake Ontario. It 

 moved through the Welland Canal and into Lake Erie 



and was first found in Lake Michigan in 1949. With few 

 fishes to eat it or compete with it. the Alewife thrived and 

 became abundant. 



A control program has lowered the munber of lampreys 

 in the lake and with the lampreys under control, popula- 

 tions of other predator fish could make a comeback. To 

 aid in building the populations of game fish in Lake Michi- 

 gan Lake Trout and Rainbow Trout have been stocked 

 in large numbers. 



In 1966, the State of Michigan released Coho Salmon 

 {Oncorhynchus kisutch) in streams that empty into the lake. 

 This native of the Pacific Coast will not only help in im- 

 proving sport fishing in the lake, but will also aid in Ale- 

 wife control. The trout and salmon stocking may also 

 help to restore the lake's commercial fishing industry. 



The future for the fishes in Lake Michigan is difficult 

 to predict. Lamprey populations will probably remain 

 under control. Alewives will probably still be abimdant, 

 but with a restoration of predators and the establishment 

 of a commercial fishery for them, their numbers should 

 decrease. 



Journey sheets and information on this program are 

 available at either the North or South Doors and at the 

 Information Desk. This is Journey No. 54 in the Raymond 

 Foundation's Journey Program for Children. 



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