Resting on the northern edge of Indiana, Lake Michigan is home to a diverse ecosystem of plant and marine life. Lake Michigan may be one of the smaller Great Lakes, but it is still the sixth largest lake in the world. Indiana claims only 43 miles of the lake’s lengthy shoreline.
Several species of fish are native to Lake Michigan, including trout, walleye, whitefish, yellow perch, panfish, largemouth bass, smallmouth bass, bowfin and catfish.
The oldest and largest species to call Lake Michigan home is the sturgeon. This ancient fish has been around for 135 million years. In 1906, a huge sturgeon weighing a whopping 240 lbs. was caught in the lake.
In the first half of the twentieth century, Lake Michigan lost many native species of fish. Numbers declined as a result of habitat changes, commercial overfishing and introduction of invasive species.
To date, more than 180 species of non-native creatures have invaded the Great Lakes. These intruders have arrived by ship, bait bucket, and home aquarium. A few common types of invasive species present in Lake Michigan include sea lamprey, alewife, round goby, zebra mussels and quagga mussels.
Sea lamprey has posed a particular problem. Since arriving in the United States in the 1800s, these eel-like blood-sucking parasites have killed numerous fish. They made their way from the Atlantic Ocean to Lake Michigan via shipping canals. In the 1940s-1950s, sea lamprey caused mass casualties of trout in Lake Michigan.
The declining population of trout created an opportunity for another invader from the Atlantic Ocean. With predatory trout populations gone, alewife fish began to rapidly multiply. Heavy feeders, the alewife soon depleted food sources from other native fish populations.
To combat these problems, the Indiana Department of Natural Resources (DNR) began conservation efforts on Lake Michigan in the 1960s. A program to control sea lamprey was implemented. Trout were restocked in the lake. The DNR also began introducing predators of the alewife fish, like salmon. Because natural fish reproduction no longer occurs in Lake Michigan at sustainable rates, the DNR continues to restock the lake on an annual basis.
