The Midwestern Asian Carp Invasion: Updates

Obama Administration Hosts Public Meeting on Asian Carp in Chicago
April 28, 2011

Photo: Steven Vance

White House Asian Carp Director John Goss and members of the Asian Carp Regional Coordinating Committee (ACRCC) held a press conference and public meeting at Chicago’s Shedd Aquarium to discuss local, state, and federal efforts organized by the ACRCC to control the spread of Asian carp. Goss and other officials provided updates on the development of a high-pressure water cannon to be used to deter carp from reaching Lake Michigan and reported on research into the ability of Asian carp to thrive in the Great Lakes.

The water cannon being developed by the U.S. Geological Survey (USGS) employs high-pressure pulses of water to deter fish. If safety tests determine that the pulses will not damage the canal walls, cannons may be installed near the locks on the Chicago and Calumet Rivers. The locks sit at connection points between the CAWS and Lake Michigan where Asian carp might cross from the Mississippi River watershed into the Great Lakes.

In a foreboding development, lab research also performed by USGS now suggests that Asian carp, which primarily feed on plankton, can also eat Cladophora, a type of algae that has become abundant in Lake Michigan in recent years. Researchers had initially speculated that plankton levels in Lake Michigan, which have declined dramatically since the introduction of quagga mussels, might be too low to support the tremendous appetites of Asian carp. If Asian carp can supplement their plankton diets with algae, however, they would be more likely to establish populations in the Great Lakes.

Bighead Carp Captured in St. Croix River
April 21, 2011

A 27-pound bighead carp was captured in the St. Croix River, just above its confluence with the Mississippi River on the Wisconsin-Minnesota border. Biologists at the Minnesota Department of Natural Resources believe that the carp, the sixth Asian carp to be captured in the area since 2003, likely migrated up the Mississippi during high waters this spring. Although the invasive fish are common farther down the Mississippi, there are currently no known reproducing populations of Asian carp in the Wisconsin or Minnesota reaches of the river. However, there are fears populations could become established here and wreak havoc on aquatic ecosystems in the Mississippi, the St. Croix, and other inland streams and lakes.

Ecological Separation Studies

The U.S. Army Corps of Engineers (USACE) has begun a long-term, comprehensive study of potential measures to “prevent or reduce the risk” of the movement of invasive species between the Great Lakes and the Mississippi River Basin. In addition to considering scenarios for ecological separation in the Chicago Area Waterway System (CAWS), the Great Lakes and Mississippi River Interbasin Study (GLMRIS) will evaluate less drastic measures in Chicago and will also address risks and control measures at other potential connections between the two watersheds. USACE is scheduled to publish their results and recommendations for the Chicago region in 2015.

Hoping to assist and encourage USACE’s research, the Great Lakes Commission and the Great Lakes and St. Lawrence Cities Initiative have begun work on their own evaluation of ecological separation scenarios in the CAWS. More narrowly focused on ecological separation and the Chicago region than GLMRIS, the Great Lakes Commission study should be completed in 2012.

For More Information is the official website of the Asian Carp Regional Coordinating Committee, which oversees federal, state, and local efforts to control the spread of Asian carp. You can find background information both on Asian carp and the strategies being used against them, as well as updated information on Asian carp science, monitoring, and control.

For several years now, the best source by far for news and analysis regarding the Asian carp invasion has been the Milwaukee Journal Sentinel. Their long-running special report, “Great Lakes, Great Peril,” has been following Asian carp and other threats to the Great Lakes since 2003. It offers both an excellent background on the topic and accurate, in-depth reporting on new developments.