Location/Description
The U.S. Army Corps of Engineers (USACE) is the lead agency on the Mussel Coordination Team (MCT). Other members of the MCT include the U.S. Fish and Wildlife Service, the U.S. Geological Survey, the National Park Service, the U.S. Coast Guard, and the Departments of Natural Resources from Minnesota, Wisconsin, Iowa and Illinois.
MCT biologists, including USACE biologists from the St. Paul and Rock Island districts, are working to establish ten new populations of the federally endangered Higgins eye mussel (Lampsilis higginsii). Relocation sites have been established in Minnesota, Wisconsin, Illinois and Iowa. Biologists also monitor the health and status of endangered and other native mussels by sampling locations within the Upper Mississippi River (UMR) drainage. A relocation feasibility study for the federally endangered winged mapleleaf mussel (Quadrula fragosa) was completed in 2017. Important life history requirements have been identified along with population estimates and genetics studies completed to support propagation of the species. Environmental DNA surveys have been conducted since 2020, identifying the federally endangered spectaclecase mussel (Cumberlandia monodonta) populations in the UMR. Public education and outreach have been ongoing and are a critical component of the conservation efforts of endangered mussel species.
The Higgins eye and winged mapleleaf relocation plans were developed in response to the U.S. Fish and Wildlife Service’s 2000 Biological Opinion, which stated that continued operation of the 9-foot navigation channel project on the UMR system would likely jeopardize the continued existence of the federally endangered Higgins eye and result in the incidental take of winged mapleleaf. The U.S. Fish and Wildlife Service determined that operation and maintenance of the navigation pools and project-dependent commercial barge transportation would encourage continued zebra mussel dispersion throughout the system. Zebra mussels negatively affect the survival and recovery of the endangered mussels.
Status
The 10-year Higgins eye relocation work has been completed, and monitoring efforts are in the 19th year of a 20-year monitoring plan. As of 2025, more than 44,000 2- to 3-year-old subadults have been placed in Mississippi River Pools 2, 3, 4 and 16 and the Wisconsin and Rock rivers. Nearly 500 adults have been moved to relocation sites in Pools 2 and 3. More than 4.5 million juveniles from more than 33,000 infested fish were free released or placed in open-bottom cages from 2001 to 2012 in the Wisconsin, Iowa, Cedar and Wapsipinicon rivers. Winged mapleleaf pilot propagation studies and relocation efforts by the MCT interagency partners have been ongoing. New populations of spectaclecase have been identified within the UMR in areas where the species was thought to have been extirpated.
Authority
Formal authorization for USACE to perform operation and maintenance activities on the Upper Mississippi River System was given in the River and Harbor Acts of 1927, 1930, 1932 and 1935.
Funding
Fiscal years 2000 to 2025 $12.2 million
Fiscal year 2026 $400,000