The Rivers and Harbors Act of 1930 authorized the creation of a 9-foot navigation channel for the Mississippi River from the mouth of the Missouri River to Minneapolis, Minnesota. The St. Paul District of the U.S. Army Corps of Engineers (Corps) was tasked to maintain the channel in the Upper Mississippi River (UMR) from Minneapolis, Minnesota to Guttenberg, Iowa. The task was accomplished through the creation of a series of locks and dams and routine maintenance dredging. As a result, the Corps, along with other government agencies, continually monitors the health of the biota in rivers and streams as it relates to Corps projects in the UMR.
Freshwater mussels are possibly one of the most imperiled groups of benthic invertebrates in the United States. Over the past 30 years, they have experienced a precipitous decline in both abundance and total species. Mussels can be found in the river channel, but are typically most abundant in the shallow water on either side of the navigation channel. Currently, there are 297 species of freshwater mussels in the United States and more than a third are listed as threatened, endangered, or of special concern. Click here for information on the listed species.
The Endangered Species Act was signed into law in 1973 and has guided endangered species legislation ever since. The U.S. Fish and Wildlife Service (FWS) and National Oceanic and Atmospheric Administration (NOAA) - Fisheries split enforcement duties of the ESA. The FWS oversees all terrestrial and freshwater activities and NOAA is responsible for all marine legislation.
Uder the ESA, a species can be listed and protected under two main categories. First, a species is considered “endangered” if there is good scientific evidence that a species is in danger of extinction (either a substantial reduction in range, or a substantial decline in total number of individuals). A species can also be listed if it so closely resembles a listed species that it cannot be separated. Second, a species can be listed as “threatened” if conditions are favorable for it to become endangered (either by habitat loss or alteration).
Once an organism is listed, a recovery plan must be developed that provides steps for the recovery of the listed species. A species can only be de-listed when it has been determined that it is no longer threatened with extinction. A second provision of the ESA that applies only to federal agencies and permitted activities involves designating critical habitat for all listed species. Critical habitats are defined as areas that must be present for an endangered species to survive. Once a critical habitat has been declared for a species, then special management practices must be in place to ensure minimal critical habitat loss.
The ESA is very strict when it comes to protecting and conserving protected species, but few projects are stopped because of an endangered species issue. The law allows for public landowners to obtain an incidental take permit as long as they (the landowner) have developed an approved habitat conservation plan. The ESA also provides for an Endangered Species Committee to decide on issues concerning whether a projects’ completion takes precedence over endangered species matters. Since 1978, the committee has been convened three times.
There are currently four federally endangered species of freshwater mussel species covered by the Endangered Species Act and two candidate species in the UMR. These species are the Spectaclecase (Cumberlandia monodonta, Candidate), Higgins’ Eye Pearly mussel (Lampsilis higginsii, Endangered), Scaleshell (Leptodea leptodon, Endangered), Sheepnose (Plethobasus cyphyus, Candidate), Fat Pocketbook (Potamilus capax, Endangered), and Winged Mapleleaf (Quadrula fragosa, Endangered). Final recovery plans for Higgins’ Eye Pearly mussel, Scaleshell, Fat Pocketbook, and Winged Mapleleaf are available via the FWS.