News Release
Southeast Region


Map of the Southeast Region Map of Kentucky Map of the Caribbean and Navassa Map of North Carolina Map of Tennessee Map of South Carolina Map of Arkansas Map of Louisiana Map of Mississippi Map of Alabama Map of Georgia Map of Florida

Service Estimates Economic Impact of Critical Habitat Designation for Fluted Kidneyshell and Slabside Pearlymussel

April 26, 2013



A light and dark brown mussel in a river

Slabside pearlymussel. Photo: Brett Ostby


The U.S. Fish and Wildlife Service announces the availability of a draft economic analysis considering the impact of a proposal to designate critical habitat for two freshwater mussels proposed for listing as endangered. 

If the two species are listed, and if critical habitat is finalized as it is proposed, the draft economic analysis suggests a range of economic impacts that are possible as a result.

In addition to opening a public comment period on the draft economic analysis, the Service is re-opening a public comment period on the proposal to designate critical habitat for these mussels under the Endangered Species Act (ESA) for 30 days by May 29, 2013, in order to allow comments on the draft analysis and the proposed critical habitat designation.  The Service first released the proposed critical habitat designation for public comment in October 2012. 

The fluted kidneyshell and the slabside pearlymussel are only found in portions of the Cumberland and Tennessee River systems of Alabama, Kentucky, Mississippi, Tennessee, and Virginia.  They have both been eliminated from more than 60 percent of the total number of streams where they historically lived.  Only a handful of populations of both species are considered biologically viable.  The primary reasons for these mussels’ decline include impoundments, mining, oil and gas exploration, sedimentation, chemical contaminants, temperature alterations, recurring drought and flooding, population fragmentation and isolation, loss of fish hosts, and the introduced, invasive Asian clam. 

The economic analysis estimates the total incremental cost of critical habitat designation to be up to $3.5 million over 20 years.  These costs stem from the requirement for federal agencies to consult with the Service regarding the impacts of their actions, or those that they fund or authorize, on critical habitat.  Other sectors of the economy likely to be subject to the impacts include commercial, industrial, residential, utility development, agricultural, and recreational development.  The majorities of these costs are administrative and may be borne by federal and state agencies; however, some costs may be incurred by local governments and businesses if federal funding or a federal permit is involved. 

Critical habitat is a term defined in the ESA.  It refers to specific geographic areas that are essential to the conservation of a threatened or endangered species and which may require special management considerations or protection.  The designation of critical habitat on private land has no impact on private landowner activities that do not require federal funding or permits. In total, the Service is proposing 27 critical habitat units encompassing 1,380 miles (2,218 km) in Alabama, Kentucky, Mississippi, Tennessee, and Virginia for the fluted kidneyshell and slabside pearlymussel.  Some of the units overlap and are proposed critical habitat for both species.

Here are the proposed critical habitat designations for each mussel.   For the fluted  kidneyshell, the Service is proposing 24 critical habitat units encompassing 1,182 miles (1,899 km) of stream channel in Kentucky, Tennessee, and Virginia.  For the slabside pearlymussel, thirteen critical habitat units encompassing 971 miles (1,562 km) of stream channel in Alabama, Mississippi, Tennessee, and Virginia are proposed for the slabside pearlymussel. 

The fluted kidneyshell’s proposed designation includes eight streams of unoccupied habitat. There are no unoccupied streams designated for the slabside pearlymussel.  All streams proposed as critical habitat are occupied by one of these species, or by another previously listed mussel species.  Unoccupied habitats provide additional habitat for population expansion and promote genetic diversity, which will decrease the risk of extinction for these two species.  For example, the Elk, Holston, and French Broad rivers are being proposed as unoccupied critical habitat for the fluted kidneyshell.  This species was once found in these areas.  Although there are no recent records of the fluted kidneyshell in these reaches, they remain essential to the conservation and eventual recovery of the species, and conditions in these streams appear to have improved because of river improvement efforts initiated by the Tennessee Valley Authority as a result of its Reservoir Releases Improvements/Lake Improvement Plan.

Within the proposed critical habitat designation for the fluted kidneyshell and slabside pearlymussel, the Reservoir Releases Improvements/Lake Improvement Plan improved water releases from Cherokee Dam on the Holston River; Douglas Dam on the French Broad River; Apalachia Dam on the Hiwassee River; Tims Ford Dam on the Elk River; and Normandy Dam on the Duck River.  Portions of all of these rivers below their dams are proposed as critical habitat for one or both mussels.

The Service is seeking input from members of the scientific community and the public before any final decision on the proposal is made.  Please submit comments concerning:

  • Any new scientific and commercial information and data concerning any threats to these species.
  • Any information concerning range, distribution, and population size of these species, including the locations of any additional populations.
  • The biological or ecological requirements of these species.
  • Current or planned activities in the areas occupied by these species and possible impacts of listing on these activities.
  • Why the Service should or should not designate these areas as “critical habitat,” including whether there are threats to these mussels from human activity, the degree of which the threats can be expected to increase or decrease due to the designation, and whether the benefit of designation would outweigh threats to these species caused by the designation, such that the designation of critical habitat is prudent.
  • Information on any foreseeable economic, national security, or other relevant impacts resulting from the proposed designation.
  • Whether the Service could improve or modify its approach to designating critical habitat in any way to provide for greater public participation and understanding, or to better accommodate public concerns or comments.

The public may mail comments and materials concerning this proposed rule to Public Comments Processing, Attn: FWS–R4–ES–2012–0004 (for proposed listing), or Attn: FWS–R4–ES–2013–0026 for (proposed critical habitat designation); Division of Policy and Directives Management; U.S. Fish and Wildlife Service; 4401 N. Fairfax Drive, MS 2042–PDM; Arlington, VA 22203.  Comments also can be filed electronically at, using the docket numbers listed above.  We will also accept public comments at a public informational session and hearing on this proposed rule on May 14, 2013, from 6 to 9 p.m. at Virginia Highlands Community College, Learning Resource Center, 110 Opportunity Lane, Abingdon, Virginia 24212-0828.

All comments must be received by May 29, 2013, and must include a first and last name, city, state, country and zip code.  Any comments and materials the Service receives, as well as supporting documentation used in preparing this proposed rule, will be available for public inspection on, or by appointment during normal business hours, at the U.S. Fish and Wildlife Service office in Cookeville, Tennessee, telephone 931-528-6481.


The mission of the U.S. Fish and Wildlife Service is working with others to conserve, protect, and enhance fish, wildlife, plants, and their habitats for the continuing benefit of the American people. We are both a leader and trusted partner in fish and wildlife conservation, known for our scientific excellence, stewardship of lands and natural resources, dedicated professionals, and commitment to public service. For more information on our work and the people who make it happen, visit Connect with our Facebook page at, follow our tweets at, watch our YouTube Channel at and download photos from our Flickr page at


Return to the 2013 News Releases

Last updated: April 26, 2013