William Cope

Freshwater mussels are among the most endangered faunal groups in the world. In North Carolina, there are eight species either federally listed or proposed for listing under the Endangered Species Act. As such, propagation has become an important tool for mussel conservation in the state. Traditional propagation activities involve inoculating host fish with mussel larvae to take them through metamorphosis and to the next life stage in captivity. In vitro techniques bypass the mussel’s obligate fish host and allow for transformation in a petri dish or culture flask using modified cell culture techniques. This method has potential to be extremely effective, transforming a greater percentage of an adult mussel’s brood than does exposure to a host fish. Unfortunately, in vitro propagated mussels have often had less vigor and lower survivability compared to their in vivo counterparts. With the establishment of the Yates Mills Aquatic Conservation Center (YMACC), NC State University will be involved in mussel propagation research and production for conservation well into the future. We propose supplementing the traditional propagation at the YMACC with in vitro efforts to both boost overall production and conducting research to refine the technique to make this methodology more efficient. Our initial target species include Dwarf Wedgemussel, Tar River Spinymussel, Yellow Lance, and Atlantic Pigtoe. Proposed research tasks include evaluating different media recipes and serum types and characterizing the juvenile mussel gut microbiome to identify potential beneficial probiotics in early grow-out. A final task will coalesce our developing expertise to directly compare in vitro versus in vivo techniques to determine which is most efficient and effective for each of the target species.

Freshwater mussels of the family Unionidae are filter-and deposit-feeding aquatic organisms that live burrowed in sediments of our streams and rivers. Unfortunately, they are in serious global decline and urgently need protection and conservation. The declines in the abundance and diversity of native North American mussels, snails, fishes, and amphibians have been attributed to a wide array of human activities that cause pollution and water-quality degradation, and habitat destruction and alteration. These types of threats remain present, and unfortunately, these organisms residing in the streams of North Carolina have experienced similar declines. For some water quality constituents and pollutants such as ammonia, heavy metals, major ions, and others, unionid mussels are known to be among the most sensitive faunal groups in aquatic systems. Mussels and other aquatic organisms are exposed to these compounds through multiple routes including surface water, sediment, porewater, and diet, and for many chemicals, the newly transformed juvenile mussel is the most sensitive life stage, although this may vary by species and compound. The most effective ways to determine suitable water quality and protective chemical thresholds are to perform in situ measurements of organism growth and survival using caged organism studies coupled with simultaneous measurements of water and sediment quality or through toxicity testing with standard methods in a controlled laboratory setting. This project will develop and implement a rigorous water quality and habitat testing program for reintroduction and restoration initiatives targeting imperiled mussels and other priority aquatic species (Dwarf Wedgemussel (Alasmidonta heterodon), Yellow Lance (Elliptio lanceolata), Atlantic Pigtoe (Fusconaia masoni), Carolina Madtom (Noturus furiosus) and Neuse River Waterdog (Necturus lewisi) in the Complete 540 project area of North Carolina. We will utilize captively propagated organisms produced at the Yates Mill Aquatic Conservation Center (YMACC) or by its state and federal partners to determine whether the water and sediment quality conditions present in the streams targeted for species reintroduction are conducive to their long-term survival, growth, and reproduction. The development and implementation of this water quality testing program for the target imperiled aquatic species at extant and reintroduction sites will be essential for long-term success of conservation efforts because proper site selection requires an improved understanding of the factors required to support fully the species.

Native freshwater snails (gastropods) are a highly diverse and globally imperiled fauna. Throughout North America and in North Carolina in particular, there are numerous imperiled snail species and one, the Magnificent Ramshorn (Planorbella magnifica), is currently a candidate for listing as threatened or endangered under the U.S. Endangered Species Act. The Magnificent Ramshorn is a large air-breathing snail endemic to four lentic systems in the Cape Fear River basin of southeastern North Carolina. It was last documented in sampling conducted in 2004 and based on the results of recent repeated surveys by qualified species experts, there appear to be no extant populations of Magnificent Ramshorn remaining. The failure to detect the species in surveys to date in the species’ historical habitat and suitable habitat in surrounding areas indicates that the species is likely extirpated in the wild. However, captive populations of the snail are being held at three separate (ark) locations in North Carolina to prevent extinction; one in our laboratory at NC State University, one at the NC Wildlife Resources Commission Marion Conservation Aquaculture Center, and one at the Coastal Plain Conservation Group. We and these other two facilities have used basic aquatic culture techniques to sustain the captive populations through multiple generations, but additional research and testing is urgently needed to improve and expand their culture, propagation, and eventual restoration back into the wild. In this project, we will conduct research that will enhance captive propagation methods, the understanding of water quality and habitat characteristics influencing their survival, growth and reproduction, the genetic consequences of small population sizes, and the restoration and monitoring of Magnificent Ramshorn snails reintroduced into the wild.

Pesticide Envir. Trust Fund

Atlantic Pigtoe, Dwarf Wedgemussel, Yellow Lance, and Tar River Spinymussel are four imperiled mussel species whose habitats lie within and may be affected by construction in the 540 project area. In order to address conservation needs for this species, tools must be developed that will allow researchers and natural resource managers to examine and monitor their health, including genetic fitness. In this project, we propose to analyze the current genetic diversity, population structure, and effective population sizes of these four species using molecular markers (single nucleotide polymorphisms, SNPs). These SNPs will then be used to establish standardized panels for each species that can be used to monitor genetic diversity and hatchery contribution as populations are augmented or reintroduced. We will also examine the overall fitness of the four target species within priority watersheds and hatcheries (Yates Mill Aquatic Conservation Center and NC Wildlife Resources Commission Conservation Aquaculture Center) by examining microbial, fungal, and viral communities through the use of histology and genetic sequencing, and using the field of “-omics” ( metabolomics, proteomics, transcriptomics) to define and compare levels of fitness between and within wild, restored, and hatchery held populations and individuals. After establishing a baseline of health and fitness, we will develop a suite of biomarkers and mussel health metrics that can be used to assess the health and fitness of mussel populations and that can be used to inform management actions, hatchery operations, and species restoration efforts. Finally, we will define and begin implementation of quantifiable conservation targets based on the tools developed in the previous two objectives. We will synthesize the research completed in the first two objectives to set measurable conservation targets for each of the four priority species through a use of various models and workshops. We then expand the techniques from objectives 1 and 2 to evaluate the conservation targets.

Atlantic Pigtoe, Dwarf Wedgemussel, Yellow Lance, and Tar River Spinymussel are four imperiled mussel species whose habitats lie within and may be affected by construction in the 540 project area. In order to address conservation needs for this species, tools must be developed that will allow researchers and natural resource managers to examine and monitor their health, including genetic fitness. In this project, we propose to analyze the current genetic diversity, population structure, and effective population sizes of these four species using molecular markers (single nucleotide polymorphisms, SNPs). These SNPs will then be used to establish standardized panels for each species that can be used to monitor genetic diversity and hatchery contribution as populations are augmented or reintroduced. We will also examine the overall fitness of the four target species within priority watersheds and hatcheries (Yates Mill Aquatic Conservation Center and NC Wildlife Resources Commission Conservation Aquaculture Center) by examining microbial, fungal, and viral communities through the use of histology and genetic sequencing, and using the field of “-omics” ( metabolomics, proteomics, transcriptomics) to define and compare levels of fitness between and within wild, restored, and hatchery held populations and individuals. After establishing a baseline of health and fitness, we will develop a suite of biomarkers and mussel health metrics that can be used to assess the health and fitness of mussel populations and that can be used to inform management actions, hatchery operations, and species restoration efforts. Finally, we will define and begin implementation of quantifiable conservation targets based on the tools developed in the previous two objectives. We will synthesize the research completed in the first two objectives to set measurable conservation targets for each of the four priority species through a use of various models and workshops. We then expand the techniques from objectives 1 and 2 to evaluate the conservation targets.

The southeastern United States is the richest region of global diversity for freshwater mussels, snails, fish, and crayfish, and is, therefore, a region of high conservation priority. However, this high regional biodiversity intersects with intense pressures of urban and suburban development and sprawl, increasingly intensive agricultural practices, and growing demands on water and other natural resources for human use. Nestled within this complex landscape, and falling within this rich faunal province, North Carolina contains streams that drain to the Interior Basin (Tennessee – Cumberland) in the west and to the Atlantic Ocean (Atlantic Slope) in the Piedmont and East. The species of freshwater mussels (Unionoida), snails, and fish vary among these regions of the state, face differing landscape and water quality challenges, and, therefore, have differing statuses of conservation concern. For example, the North Carolina Wildlife Resources Commission and the North Carolina Natural Heritage Program recognize approximately 50 species of freshwater mussels native to North Carolina and identifies 31 (62%) as Species of Greatest Conservation Need in the Wildlife Action Plan. Because of these declines and degree of imperilment, protection, restoration, and conservation of these irreplaceable aquatic organisms are paramount. This project will specifically benefit the species impacted by the North Carolina Department of Transportation’s Complete 540 road project and contains tasks related to their captive propagation and culture for restoration and recovery. The specific tasks will focus on the propagation and culture of the Dwarf Wedgemussel, Yellow Lance mussel, Tar River Spinymussel, the Atlantic Pigtoe mussel, the Magnificent Ramshorn snail, the Neuse River waterdog, Carolina Madtom, and others as requested by partner state and federal natural resource agencies. This project will facilitate the continuing efforts for these species that have previously been supported by the National Fish and Wildlife Foundation, the North Carolina Wildlife Resources Commission, and the U.S. Fish and Wildlife Service. The outcomes will provide natural resource managers and other decision makers with the tools, organisms, and science-based information needed to restore, improve, and conserve these taxa.

The southeastern United States is the richest region of global diversity for freshwater mussels, snails, fish, and crayfish, and is, therefore, a region of high conservation priority. However, this high regional biodiversity intersects with intense pressures of urban and suburban development and sprawl, increasingly intensive agricultural practices, and growing demands on water and other natural resources for human use. Nestled within this complex landscape, and falling within this rich faunal province, North Carolina contains streams that drain to the Interior Basin (Tennessee – Cumberland) in the west and to the Atlantic Ocean (Atlantic Slope) in the Piedmont and East. The species of freshwater mussels (Unionoida), snails, and fish vary among these regions of the state, face differing landscape and water quality challenges, and, therefore, have differing statuses of conservation concern. For example, the North Carolina Wildlife Resources Commission and the North Carolina Natural Heritage Program recognize approximately 50 species of freshwater mussels native to North Carolina and identifies 31 (62%) as Species of Greatest Conservation Need in the Wildlife Action Plan. The proposed research will specifically benefit these species and contains tasks related to their captive propagation and culture for restoration and recovery.

The freshwater aquatic organisms that inhabit rivers, especially those that reside in coastal drainages live in constrained corridors. Thus, populations can only move and adapt to changing environmental conditions in a longitudinal manner (upstream to downstream or downstream to upstream). Many of these organisms have evolved and adapted to live in preferred habitats and water quality conditions within these streams, and relatively rapid human-induced changes pose a unique challenge for their continued survival and persistence. This is especially true for our native freshwater mussels belonging to the family Unionidae, which are already among the most imperiled groups of fauna on the planet. One such factor associated with changing environmental conditions in a climate-influenced scenario that may adversely impact freshwater mussels inhabiting coastal rivers is sea level rise and accompanying changes in the salinity regime. For example, a recent published study has shown that 42% of coastal North Carolina could be inundated with 100 cm of sea level rise and that evaluating this risk is essential for understanding adaptation potential and decision making. Therefore, the overall aim of this project is to investigate the adaptation and vulnerability potential of a native freshwater mussel living in coastal riverine drainages to climate-induced, sea level rise, specifically fluctuating salinity, temperature, and flow regimes. The specific objectives of our study are to: (1) assess the vulnerability of the Tidewater Mucket (Leptodea ochracea), an imperiled freshwater mussel species that resides in lower Atlantic Slope coastal drainages to salinity by conducting standard sensitivity tests with early life stages (e.g., larvae, juveniles) of the mussel under controlled laboratory conditions; (2) determine the potential effects of natural riverine salinity gradients on adult mussels by conducting a reciprocal transplant experiment with salinity adapted and non-salinity adapted mussels; and (3) develop a risk-based scenario of mussel salinity tolerances in existing occupied habitats incorporating predictions in sea level rise and projected salinity ranges. This project directly addresses Southeast Climate Adaptation Science Center and partner agency priority topics and is a collaborative effort among North Carolina State University, the U.S. Geological Survey’s North Carolina Cooperative Fish and Wildlife Research Unit, the U.S. Fish and Wildlife Service’s Raleigh North Carolina Field Office, the North Carolina Wildlife Resources Commission, the Virginia Department of Game and Inland Fisheries, and the University of Georgia. The peer-reviewed publications, relevant infographics for web sites, and visualization maps of the overlap of sea level rise and mussel salinity sensitivity that will comprise our primary products and deliverables will illustrate the areas of rivers where mussels may be lost or conserved due to climate-induced salinity changes and will provide federal and state natural resource managers, policy makers, and future researchers with actionable management and conservation information and potential options for maintaining this highly imperiled, but valuable molluscan resource in the face of predicted climate-induced sea level rise and salinity fluctuations.

The Southeastern and Mid-Atlantic regions of the United States contain the greatest biodiversity of native freshwater mussels in the world, but they are highly imperiled due to habitat alteration and destruction, pollution and poor water quality, and the introduction of aquatic invasive species. Over recent decades, U.S. Fish and Wildlife Service and state fish and wildlife management agency biologists have responded to an increased frequency of mussel die-offs, enigmatic declines, and problems with decreased mussel growth and survival, but a definiticve cause has yet to be identified. However, a recent, but unexplained relation has been identified between manganese (Mn) concentrations and several of these mussel decline and die-off events. Therefore, we propose to examine the toxicity of Mn to mussels in controlled laboratory tests with captively propagated larval and juvenile mussels and with adult mussels collected from low Mn-containing streams. We will then compare these findings to mussels and Mn concentrations in water and sediment from streams where die-offs and declines have occurred. This high impact project focuses on native freshwater mussel conservation priorities of the Southeast region and potentially nation-wide. The project has direct links to the strategic science needs of the natural and cultural resource managers in the region and beyond, because it addresses specific priorities outlined in the State Wildlife Action Plans for the conservation of native freshwater mussels in the States of North Carolina and Virginia and federal at-risk molluscan species in Region 4 and Region 5 of the USFWS and others across the country. In addition, this project will have direct relevance and benefit to other federal resource management and research agencies, such as the U.S. Environmental Protection Agency, who utilize the mussel toxicity data in water quality criterion development. The completion of these research objectives will provide natural resource managers and other decision makers with real-world exposure and survival scenarios and would directly impact the recovery plan for the endangered Appalachian Elktoe mussel by informing the potential causal mechanisms for its die-off and decline in the Little Tennessee River of North Carolina. The persistence of all freshwater mussels will be addressed in the scope of the project.