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Tuesday, April 19, 2011

Asian Carp and the Great Lakes Region

Eugene H. Buck
Specialist in Natural Resources Policy

Harold F. Upton
Analyst in Natural Resources Policy

Charles V. Stern
Analyst in Natural Resources Policy

Cynthia Brougher
Legislative Attorney

Four species of non-indigenous Asian carp are expanding their range in U.S. waterways, resulting in a variety of concerns and problems. Three species—bighead, silver, and black carp—are of particular note, based on the perceived degree of environmental concern. Current controversy relates to what measures might be necessary and sufficient to prevent movement of Asian carp from the Mississippi River drainage into the Great Lakes through the Chicago Area Waterway System. Several bills have been introduced in the 112th Congress to direct actions to avoid the possibility of carp becoming established in the Great Lakes.

According to the Great Lakes Fishery Commission, Asian carp pose a significant threat to commercial and recreational fisheries of the Great Lakes. Asian carp populations could expand rapidly and change the composition of Great Lakes ecosystems. Native species could be harmed because Asian carp are likely to compete with them for food and modify their habitat. It has been widely reported that Great Lakes fisheries generate economic activity of approximately $7 billion annually. Although Asian carp introduction is likely to modify Great Lakes ecosystems and cause harm to fisheries, studies forecasting the extent of potential harm are not available. Therefore, it is not possible to provide estimates of potential changes in the regional economy or economic value (social welfare) by lake, species, or fishery.

The locks and waterways of the Chicago Area Waterway System (CAWS) have been a focal point for those debating how to prevent Asian carp encroachment on the Great Lakes. The CAWS is the only navigable link between the Great Lakes and the Mississippi River, and many note the potential of these waterways to facilitate invasive species transfers from one basin to the other. The U.S. Army Corps of Engineers has constructed and is currently operating electrical barriers to prevent fish passage. However, in light of recent indications that Asian carp may be present upstream of the barriers and in Lake Michigan, increased federal funding to prevent fish encroachment (largely through the EPA Great Lakes Restoration Initiative) has been announced by the Obama Administration, and calls to permanently separate the two basins have grown. The potential closure of existing navigation structures in the CAWS and the permanent separation of the basins are currently the most contentious issues related to Asian carp control in the region, and a long-term solution has yet to be decided.

Since December 2010, Michigan and several other Great Lakes states have filed a number of requests for court ordered measures to stop the migration of invasive Asian carp toward Lake Michigan from the Mississippi River basin via the CAWS. The U.S. Supreme Court denied several motions for injunctions to force Illinois, the U.S. Army Corps of Engineers, and the Metropolitan Water Reclamation District of Greater Chicago to take necessary measures to prevent the carp from entering Lake Michigan. Michigan, Minnesota, Ohio, Pennsylvania, and Wisconsin sought a separate order in federal district court seeking similar relief, which was also denied.

In the 112
th Congress, H.R. 892 and S. 471 would direct the Corps of Engineers, U.S. Geological Survey, and FWS to take measures to control the spread of Asian carp, including studying the feasibility of the hydrological separation of the Great Lakes and Mississippi River Basins.

Date of Report: April 5, 2011
Number of Pages: 26
Order Number: R41082
Price: $29.95

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