Kelly DeGrandchamp is tracking some mighty big fish. They don't belong in the Midwest, but they're here to stay--so wildlife managers need to learn what they can about these invasives to keep them under control.

They're Asian carp, which grow up to 100 pounds. They come as two kinds, the bighead carp and the silver carp. Both species escaped from southern fish farms during floods and have been making their way north up the Mississippi, Ohio, and Illinois rivers. The Army Corps of Engineers is taking expensive measures to keep the carp from getting a foothold in the Great Lakes, but that may be a losing battle.

These fish pose a big menace to ecosystems because they eat huge quantities of phytoplankton, the invertebrates that fuel small fish. And with small fish edged out of the competition for food, larger predator fish such as lake trout also decline in numbers.

For her master's thesis in zoology, DeGrandchamp has been tracking bighead and silver carp in an 80-mile stretch of the lower Illinois River and one of its backwaters. She's getting a picture of their movements, especially during spawning season, and seeing what habitats they favor over the course of the year.

The information she gleans will give wildlife managers more ammunition to control these invasive species by revealing where the Asian carp are competing with native fish for food. The Army Corps of Engineers, U.S. Fish and Wildlife Service, and Illinois Department of Natural Resources are supporting DeGrandchamp's work, done with guidance from zoology professor James Garvey and SIUC's Fisheries and Illinois Aquaculture Center.

--by Marilyn Davis, ed.

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