Endangered and Threatened Freshwater Mussels Impacted By Post-Helene Debris Removal
By Hans Lohmeyer, Stewardship Coordinator
In the wake of Hurricane Helene, populations of two federally protected freshwater mussel species in the Little River in Transylvania County have endured not only a natural disaster but also a human-made one. While the storm caused unprecedented flooding, sedimentation, and streambank disruption, recent debris removal using heavy machinery within the river channel has resulted in significant additional impacts to these rare species. These impacts have affected both the endangered Appalachian Elktoe and the threatened Long-Solid Mussel, as well as the increasingly rare critical habitat these sensitive species depend on.
An initial snorkel survey conducted in early April at a single site on the Little River, immediately following the completion of storm debris removal work, revealed clear evidence of physical damage to freshwater mussel populations and their habitat. Crushed mussel shells with actively decomposing tissue were documented—damage consistent with the recent use of heavy machinery in-stream. Observers noted crushed shells, displaced mussels lying exposed on the streambed, and widespread areas of large rocks freshly fractured into smaller pieces and rubble. These early signs of disturbance raised immediate concerns about impacts at this specific site, which has been regularly monitored by the U.S. Fish and Wildlife Service and the North Carolina Wildlife Resources Commission due to its historically robust mussel population and rare species presence.
Following a month-long pause caused by high turbidity and unfavorable weather conditions, Hans Lohmeyer from Conserving Carolina and biologists from the NC Wildlife Resources Commission conducted a follow-up survey was conducted just days ago. The results were even more alarming: over 200 dead freshwater mussel shells were recorded, including 72 that had been visibly crushed. Several live mussels were also found with split or cracked shells, and one recently deceased Appalachian Elktoe was discovered with tissue still present. The encouraging news is that 59 live Appalachian Elktoe and 2 Long-Solid Mussels were also found within the same stretch.
It is important to acknowledge that some mussel mortality likely resulted from flooding during Hurricane Helene. However, Dr. Michael Gangloff Professor at Appalchian State University and a freshwater conservation biologist, reviewed photos of the live mussels with damaged shells and noted, “They would have evidence of shell regeneration if the damage had occurred in late September at the time of the storm.” He further explained that “mussel tissue dissolves within two days,” suggesting that the Appalachian Elktoe specimen with intact tissue had died very recently. This timing supports the conclusion that these populations remain at risk of continued mortality due to conditions left behind by in-stream machinery use. It is also important to note that crushed shells with decomposing tissue were also found during the initial survey, conducted the day after debris removal was completed.
These findings directly contradict statements made at a recent meeting by a biologist contracted by the U.S. Army Corps of Engineers (USACE), who asserted that all federally listed mussels in the area had likely been scoured out and washed downstream during Helene. However, the evidence points to a different conclusion. Many mussels clearly survived the hurricane. What they could not survive were the tracks of excavators whose treads tore through their habitat under the guise of emergency recovery. It is deeply concerning to dismiss this level of biological loss as “the cost of doing business,” particularly when that business was carried out with little to no ecological oversight, delayed planning for work in critical aquatic habitats, and no clear accountability for minimizing harm to protected species.
The contracted biologist further acknowledged that exclusion zone maps—intended to guide storm debris removal crews away from sensitive areas—were not received until just one week prior to the meeting. By that time, work within the most intensively surveyed and biologically significant section of the Little River had already been completed, with heavy machinery operations concluding on April 8. The biologist also stated that other biologists had been on-site directing contractors to avoid known mussel habitat. However, this claim is difficult to reconcile with the extent of mussel mortality and shell damage documented at the site. The lack of timely access to critical habitat data meant that debris removal crews were operating without clear guidance during the most sensitive phase of the project. As a result, machinery entered and disturbed habitat that supports one of the strongest known populations of the federally listed Appalachian Elktoe. The absence of clearly defined avoidance areas and biological monitoring reflects a serious breakdown in coordination and risk management and ultimately contributed to the avoidable destruction of protected aquatic habitat.
The purpose of this article is not to assign blame, but to advocate for the long-term survival of two already vulnerable freshwater mussel species. The Appalachian Elktoe and Long-Solid Mussel are not only indicators of river health but are also essential to the overall function of the aquatic ecosystem. A critical first step is to conduct a comprehensive survey of the Little River to evaluate current population levels and determine the full extent of impacts from both Hurricane Helene and the recent debris removal efforts. Ensuring their survival will require more than just preventing future harm. It will demand active habitat restoration and greater support for population recovery through propagation and monitoring. Key restoration actions should include the strategic placement of large woody debris and properly sized rock structures, along with the regrading of steep streambanks to reconnect the river with its natural floodplain. Moving forward, in-depth studies are needed to assess the damage and guide the development of science-based recovery plans. These plans must be built through collaboration among federal and state agencies, private landowners, and nonprofit conservation partners. Only by fully understanding the extent of the impacts can we begin to make informed, lasting decisions that support the recovery and long-term resilience of these species in the waters they still call home.