The Suwannee moccasinshell’s range and numbers have declined in recent decades and the mussel should be protected as a threatened species, the U.S. Fish and Wildlife Service announced today. Its decline is the result of pollution and reduced flows in the Suwannee River Basin.
A listing as threatened means the Suwannee moccasinshell is considered likely to become endangered within the foreseeable future throughout all or a significant portion of its range.
The listing becomes effective November 7, 2016, 30 days after the publication of this decision in the Federal Register.
The Suwannee moccasinshell is a freshwater mussel only found in the Suwannee River Basin in Florida and Georgia. The primary reason for the species’ decline is the degradation of its habitat and poor water quality due to pollution and reduced flows. Its riverine habitats are vulnerable to degradation from numerous sources including runoff from agricultural operations, discharges or accidental releases from industrial and municipal wastewater facilities and mining operations, and groundwater extraction.
"The Suwannee moccasinshell's decline should serve as a warning to us all to take notice of declining water conditions in our rivers," said Cindy Dohner, the Service's Southeast Regional Director. "Americans need and value clean water. Mussels are indicators of how clean the water is.”
“A healthy river system means clean water for people, fish, migratory birds, and other wildlife,” Dohner said.
The mussel is currently known to live in the Suwannee River main channel and the lower Santa Fe River in Florida. An evaluation of historical and recent surveys shows the Suwannee moccasinshell’s range has declined in recent decades. It may be extirpated from the Withlacoochee River in Georgia and Florida, and its range and abundance have clearly declined in the Santa Fe River system in Florida, where it is now found only in the lower portion of the Santa Fe River mainstem in exceedingly low numbers.
The Suwannee moccasinshell continues to survive in portions of its known range in the Suwannee River mainstem, but its numbers are much lower now than a few decades ago. Despite its low abundance, populations in the Suwannee River mainstem presently appear to be stable.
The Suwannee River Basin is home to two other imperiled species. The threatened Gulf sturgeon has critical habitat in the main channel Suwannee and Withlacoochee Rivers and the endangered Oval pigtoe mussel has critical habitat in the Santa Fe and New Rivers. The Service will publish a proposal to designate critical habitat under the ESA for the Suwannee moccasinshell at a later date because more information concerning appropriate areas for the designation is needed.
Public comments and information received during the final listing decision process, as well as supporting documentation used in preparing this decision, are available online at http://www.regulations.gov. In the Search box, enter FWS-R4-ES-2015-0142, which is the docket number for this decision.
The final listing of the Suwannee moccasinshell is part of the Service’s efforts to implement a court-approved work plan aimed at addressing a series of lawsuits concerning the agency’s ESA listing program. To learn more about the Service’s work plan for 2016, please visit http://www.fws.gov/southeast/candidateconservation.
