Biosphere Journal Entry
Biosphere Journal Entry
Invasive Fish DNA in Lake Michigan (March 8, 2010)
DNA of invasive Asian carp was recently found in Lake Michigan. U.S. Fish and Wildlife Service.
After getting closer and closer for years, non-native Asian carp have finally reached Lake Michigan. DNA from the fish was found recently in the lake's Calumet Harbor near the Illinois-Indiana border. Another trace of carp DNA was found in the Calumet River just a half-mile from the lake. Biologists say the hungry invaders are a huge threat to the lake. Like other invasive species, the fish can spread havoc in an ecosystem. They crowd out native species and gobble up resources. Often, invasive species don't have competitors or natural predators.
Asian carp were first brought to the United States in the 1970s to help fish farmers in the South clean algae-filled ponds. Heavy floods helped spread the fish to the Mississippi River system in the 1990s. The invasive fish have slowly moved northward up the river ever since. When fully grown, Asian carp can weigh up to 100 pounds (40 kilograms). The fish have been known to leap high out of the water and strike boaters.
