State and federal agencies have spent millions of dollars to stop the spread of invasive carp still threatening the health of waters in the upper Midwest, including a recent data-backed effort using transmitters to track individual fish and net large numbers of them.
The invasive carp — species include bighead, black, grass and silver — were imported to the U.S. in the 1960s and 1970s in an effort to address algae, weeds and parasites in aquaculture farms. But they escaped through various means, took hold in the Mississippi River basin and have since spread north. The fish are voracious eaters, competing with native species for food and habitat.
Wildlife agencies at the federal and state levels have fought for years to slow the spread of carp across the Great Lakes and protect the region's $7 billion fishing industry — recognizing that eradication is unlikely.
Their tools are varied but include electric barriers, walls of bubbles and underwater speakers used to net large numbers of carp.
Agencies such as the U.S. Fish and Wildlife Service and state wildlife managers have built a network of receivers extending from the St. Croix River in far northern Wisconsin to the Gulf of Mexico to record tagged invasive carp’s movement, with periodic data collection. The first receivers were deployed in the Illinois River in an effort to stem migration into Lake Michigan in the early 2000s.
Beginning around 2018, managers started placing new, solar-powered receivers around the Great Lakes region that could track tagged carp and send instant notifications to observers.
