FLUTED KIDNEYSHELL (PTYCHOBRANCHUS SUBTENTUM (=SUBTENTUS)) SPECIES STATUS ASSESSMENT

Version 1.0

Photo courtesy of Bret Ostby, Virginia Tech

U.S Fish and Wildlife Service Region 4 Atlanta, Georgia

February 2021

ACKNOWLEDGEMENTS

This document was prepared by Michael Compton (Office of Kentucky Nature Preserves) in coordination with Jessica Miller (USFWS), Anthony Ford (USFWS), and Victoria Davis (USFWS).

We would also like to recognize and thank the following individuals who served on the expert team for this SSA and provided substantive information and/or insights, valuable input into the analysis, and/or reviews of a draft of this document: Don Hubbs (Tennessee Wildlife Resources Agency), Monte McGregor (Kentucky Department of Fish and Wildlife Resources), Jordan Richard (USFWS), and Brian Watson (Virginia Department of Wildlife Resources). Further peer review was provided by Gerald Dinkins (University of Tennessee) and Wendell Haag (U.S. Forest Service) (Appendix A). We appreciate their input and comments, which resulted in a more robust status assessment and final report.

Suggested reference:

U.S. Fish and Wildlife Service. 2021. Species Status Assessment Report for the Fluted Kidneyshell (Ptychobranchus subtentum (=subtentus)), Version 1.0. February 2021. Atlanta, GA.

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EXECUTIVE SUMMARY ...... iv INTRODUCTION ...... 1 INDIVIDUAL NEEDS: LIFE HISTORY AND BIOLOGY .... 4 2.1 Taxonomy ...... 4 2.2 Description ...... 5 2.3 Habitat ...... 6 2.4 Feeding and Diet ...... 6 2.5 Life History and Reproduction ...... 7 2.6 Population Needs ...... 10 2.7 Species Needs ...... 10 2.8 Range and Distribution ...... 11 FACTORS INFLUENCING VIABILITY ...... 14 Water Quality Degradation ...... 14 Habitat Degradation ...... 18 Climate Change ...... 21 Invasive Species ...... 22 Impervious Surfaces ...... 23 Undefined Threats ...... 24 Regulatory Mechanisms and Conservation Efforts ...... 24 CURRENT CONDITION AND SPECIES VIABILITY ...... 26 Methodology ...... 26 Description of Populations ...... 30 Harpeth Population ...... 30 Obey Population...... 31 Buck Creek Population ...... 33 Big South Fork Population...... 34 Rockcastle Population ...... 35 Upper Cumberland Population ...... 37 Buffalo Population ...... 38 Upper Duck Population...... 39 Pickwick Lake Population ...... 40 Lower Elk Population ...... 41 Upper Elk Population ...... 42 Wheeler Population ...... 44

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Guntersville Population ...... 45 Lower French Broad Population ...... 46 Nolichucky Population...... 47 Holston Population...... 48 North Fork Holston Population ...... 49 South Fork Holston Population ...... 50 Clinch Population...... 51 Powell Population ...... 53 Species Viability...... 54 Current Condition Summary ...... 61 FUTURE CONDITIONS ...... 62 Future Scenario Considerations ...... 62 Uncertainty ...... 65 Future Scenarios ...... 65 5.3.1 Scenario 1 ...... 65 5.3.2 Scenario 2 ...... 70 5.3.3 Scenario 3 ...... 74 Future Viability ...... 78 Overall Summary ...... 80 LITERATURE CITED ...... 82 APPENDIX ...... 99

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EXECUTIVE SUMMARY

Background

This species status assessment (SSA) report describes a comprehensive review of the available data and analytical process to assess the viability of the endangered Fluted Kidneyshell (Ptychobranchus subtentum (=subtentus)). During this process, the three conservation biology principles of resiliency, representation, and redundancy (or the “3Rs”) were evaluated for the species. The Fluted Kidneyshell is a relatively large (up to 13 centimeters (cm) (5 inches (in)) in length) freshwater mussel found historically within the Cumberland and Tennessee River drainages of the Ohio River basin in Alabama, Kentucky, Tennessee, and Virginia. The species typically occupies riffle and run habitat in small to large rivers in substrates mixed with sand and gravel and is occasionally associated with cobble and boulder. Spawning occurs in late summer, and the species is considered a long-term brooder. Several benthic fish species, such as the banded sculpin, fantail darter, and rainbow darter, are host species for the parasitic larvae (glochidia). The species is moderately long-lived; it has been estimated to live as long as 26 and 49 years (Davis and Layzer 2012, pp. 88-89; Henley et al. 2002, p. 19).

Identified threats to the species include degradation of water quality, particularly heavy metals, endocrine disruptors, nutrients and organic pollution; habitat degradation, particularly sedimentation, channel alteration and gravel mining, and impoundments and barriers; climate change; impervious surfaces; and invasive species. Regulatory mechanisms and conservation efforts have the potential to positively influence the persistence of populations.

Methodology

The SSA process can be categorized into three sequential stages. During the first stage, we considered the Fluted Kidneyshell’s life history and used the conservation biology principles of resiliency, redundancy, and representation to better understand the “needs” of populations and the species to maintain viability. The next stage involved an assessment of the historical and current condition of the species’ demographics and habitat characteristics. The final stage of the SSA involved making predictions about future viability while considering the species’ responses to anthropogenic and environmental influences that are likely to occur within its range. This process used the best available information to characterize the Fluted Kidneyshell’s viability, the ability of the species to sustain populations in the wild over time.

Pertinent information regarding environmental and biological aspects of the species, as well as all occurrence records that were readily available, were obtained from peer-reviewed articles, books, unpublished survey reports, and survey records (1825 through 2019) contained in agency databases (i.e., Kentucky Department of Fish and Wildlife Resources (KDFWR), Office of Kentucky State Nature Preserves Commission (KNP), Tennessee Department of Environment and Conservation (TDEC), Tennessee Wildlife Resources Agency (TWRA), Tennessee Valley Authority (TVA), and Virginia Department of Environmental Quality (VDEQ)) to evaluate current and future viability of the Fluted Kidneyshell. Across the range of the species, we designated populations based on Hydrologic Unit Code 8 (HUC8) and assessed the current

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resiliency of each population. HUC8 maps the sub-basin level, analogous to medium-sized river basins, about 2,200 nationwide for the conterminous United States.

We made qualitative assessments of the current condition of each population by evaluating components of the species’ physical environment (Habitat Elements) and its demographics (Population Elements). We selected components that had supporting data comparable across the range of the species at a resolution suitable for assessing the species at the population level. Habitat elements included water quality, habitat quality, and connectivity. Population elements included occurrence extent (number of occupied HUC10s), abundance (total number of live or fresh dead specimens encountered), continuity (length of longest continuous occupied stream segment), and complexity (number of tributaries occupied, plus the mainstem). The condition score for each Fluted Kidneyshell population that was then used to assess the Fluted Kidneyshell’s current condition across its range relative to the “3Rs” described below:

Resiliency is assessed at the population level and describes the ability of a species to withstand stochastic disturbance (arising from random factors). Resiliency is positively related to population size, growth rate, and fecundity and may be influenced by connectivity among populations. Generally, populations need sufficient numbers of individuals within habitats of adequate area and quality to maintain survival and reproduction in spite of disturbance. Resilient populations are better able to withstand disturbances, such as random fluctuations in birth rates (demographic stochasticity), variations in rainfall (environmental stochasticity), or the effects of anthropogenic activities.

Redundancy describes the ability of a species to withstand catastrophic events (a rare destructive natural event or episode involving many populations). Generally speaking, redundancy is best achieved by having multiple, resilient (connected) populations widely distributed across the species’ range. Having multiple populations reduces the likelihood that all populations are affected simultaneously, while having widely distributed populations reduces the likelihood of populations possessing similar vulnerabilities to a catastrophic event. Given sufficient redundancy, single or multiple catastrophic events are unlikely to cause the extinction of a species. Therefore, as redundancy increases, species viability also increases.

Representation describes the ability of a species to adapt to changing environmental conditions over time and is characterized by the breadth of genetic and environmental diversity within and among populations. The more representation, or diversity, a species has, the more it is capable of adapting to changes (natural or human caused) in its environment. In the absence of species-specific genetic and ecological diversity information, we evaluate representation based on the extent and variability of habitat characteristics across the geographical range and other factors that may be appropriate to the species.

Similar methodology was used to project the future condition of the Fluted Kidneyshell. We considered a variety of stressors, including pollution, climate change, urbanization, and habitat fragmentation, and their potential effects on population resiliency. To account for the possible variation and complexity of outcomes into the future, three plausible scenarios were used to project the resiliency of each population 50 years from now. Each scenario was informed, in

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part, on the predictive models associated with urbanization (Terando et al. 2014, entire) and climate change (International Panel on Climate Change 2014, p. 56-74). An important assumption of the predictive analysis was that future population resiliency is largely dependent on the habitat elements we identified.

We assessed how Fluted Kidneyshell populations would respond to the projected future condition. Under Scenario 1, factors influencing current Fluted Kidneyshell populations were projected to remain constant into the future. Under Scenario 2, threats influencing current Fluted Kidneyshell populations were projected to worsen, and, under Scenario 3, threats influencing current Fluted Kidneyshell populations were projected to become less severe and conservation efforts would increase.

Conclusions

Current Condition

Currently ten of the twenty historical Fluted Kidneyshell populations are extant, with three and seven populations occupying the Cumberland and Tennessee River drainages, respectively (Figure E1). Several of the extirpated populations are the result of impoundments (i.e., Holston), while the causes of the other extirpations are not clear. Numerous threats within the range of the species degrade water quality and habitat for aquatic species in general (e.g., land development, agricultural practices, fossil fuel extraction, and fragmentation); however, the magnitude of threat these threats pose to Fluted Kidneyshell and other freshwater mussels is poorly understood. None of the extant populations exhibit high resiliency; five are considered to have moderate resiliency and the other five, low resiliency. The Upper Duck, Lower Elk, and Nolichucky Rivers populations are extant because of reintroductions. These reintroductions are relatively recent, the earliest occurring in 2004. The Upper Duck population has exhibited some natural recruitment (Wisniewski 2020, p. 12). No recruitment of the Lower Elk or Nolichucky populations have been documented as of yet. The Clinch population is the largest population with over 10,000 individuals distributed through over 100 km (62 mi.) of stream length in the mainstream and multiple tributaries. However, recent mussel die-offs in the Clinch River from a novel densovirus (Richard et al. 2020, entire) escalates the concern for mussels within that system. The species continues to occupy the Cumberland and Tennessee River drainages, but it has lost some of its historical representation in ecoregions. Natural populations (i.e., not from reintroductions) remain in two of the four historically occupied ecoregions. Given the loss of representation and the low to moderate resiliencies of all extant populations, we consider the species’ representation to be low. Likewise, considering the low resiliencies of half of the extant populations, we consider the species to have low redundancy.

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Figure E1. Current condition of Fluted Kidneyshell populations.

Future Condition

Under Scenario 1 (Status Quo), the trajectories of environmental conditions and conservation efforts continue along their current paths. We project four populations to become extirpated and two of the six remaining populations to decrease in resiliency (Table E1). The Big South Fork population (low resiliency) will be the only remaining population in the Cumberland River drainage. The reintroduced Upper Duck population (Clinch River stock) will be the only remaining population within the Interior Plateau ecoregion (low resiliency).

Under Scenario 2 (Pessimistic), environmental conditions deteriorate and water quality and habitat degradation becomes more severe due to increased urbanization, greater effects from climate change, and decreased conservation efforts. We project six of the current populations to become extirpated and all of the remaining four populations to decrease in resiliency to low. All representation within the Central Appalachians and Interior Plateau ecoregions will be lost. The Big South Fork population will be the only extant population within the Southwestern Appalachians ecoregion and in the Cumberland River drainage. The three other populations are within the upper Tennessee River drainage within the Ridge and Valley ecoregion.

Under Scenario 3 (Optimistic), environmental conditions improve, past reintroductions are successful, and future reintroductions and augmentations occur. We project that all ten of the current populations will persist, and one new population (Rockcastle) will become established

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through reintroduction. The resiliency of four populations would increase to moderate, and the Clinch would increase to high.

Table E1. Resiliency condition summary of Fluted Kidneyshell populations. Projected changes to the current condition are bolded in the table. Projected Future Scenarios Drainage Populations Current 1 2 3 Condition (Status Quo) (Pessimistic) (Optimistic) Cumberland Harpeth Extirpated Extirpated Extirpated Extirpated Obey Low Extirpated Extirpated Moderate Buck Creek Low Extirpated Extirpated Low Big South Fork Moderate Low Low Moderate Rockcastle Extirpated Extirpated Extirpated Low Upper Cumberland Extirpated Extirpated Extirpated Extirpated Tennessee Buffalo Extirpated Extirpated Extirpated Extirpated Upper Duck Low Low Extirpated Moderate Pickwick Lake Extirpated Extirpated Extirpated Extirpated Lower Elk Low Extirpated Extirpated Moderate Upper Elk Extirpated Extirpated Extirpated Extirpated Wheeler Lake Extirpated Extirpated Extirpated Extirpated Guntersville Lake Extirpated Extirpated Extirpated Extirpated Lower French Broad Extirpated Extirpated Extirpated Extirpated Nolichucky Moderate Low Extirpated Moderate Holston Extirpated Extirpated Extirpated Extirpated North Fork Holston Moderate Moderate Low Moderate South Fork Holston Low Extirpated Extirpated Moderate Clinch Moderate Moderate Low High Powell Moderate Moderate Low Moderate Total extant 10 6 4 11 populations:

Overall, the species will continue to be exposed to numerous threats that increases the risk of extirpations. Conservation efforts, such as reintroductions and population augmentation, and environmental improvements can mitigate or minimize the threats to abate extirpation and maintain species persistence. We project a substantial loss of viability under future Scenarios #1 and #2. We project that the viability will improve marginally under Scenario #3, which is contingent on the success of conservation activities to improve habitat conditions and implement population reintroductions and augmentations.

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INTRODUCTION

The Fluted Kidneyshell (Ptychobranchus subtentum (=subtentus))1 is a freshwater mussel historically found within the Cumberland and Tennessee River drainages of the Ohio River bBasin in Alabama, Kentucky, Tennessee, and Virginia. On September 26, 2013, the U.S. Fish and Wildlife Service (Service) listed the species as endangered under the Endangered Species Act of 1973, as amended (Act) (USFWS 2013a, entire). Listing under the Act triggers certain requirements of the Service, including preparation of a species recovery plan. Recovery plans include descriptions of actions that may be necessary for the conservation and survival of the species; objective, measurable criteria for determining when the species can be reclassified from endangered to threatened or considered for removal from the list; and an estimate of the time and cost required to carry out the actions needed to recover the species. The Act also requires other Federal agencies to (1) utilize their authorities to carry out conservation programs for the conservation of threatened and endangered species and (2) to consult with the Service to ensure that actions they undertake, permit, or fund do not jeopardize the continued existence of listed species or adversely modify designated critical habitat. Fulfilling these responsibilities requires use of the best scientific and commercial data available.

The Species Status Assessment (SSA) framework (USFWS 2016, entire) is designed to be a comprehensive scientific review of a species’ biology and threats, an evaluation of its biological status, and an assessment of the resources and conditions needed to maintain long-term viability. The intent of the SSA Report is to be easily updated as new information becomes available and to support the functions of the Endangered Species Program, including Recovery. As such, the SSA Report will be a living document that supports other decision documents, such as recovery plans and five-year reviews. The SSA Report is not a decisional document, but rather a support document to assist conservation managers.

Our approach for assessing the viability of the Fluted Kidneyshell involved three general stages (Figure 1.1). In Stage 1, we described the species’ needs (or ecology) in terms of its resiliency, redundancy, and representation (“3 Rs”, as adapted from Shaffer and Stein (2000, entire)). Specifically, we identified the ecological requirements for survival and reproduction at the individual, population, and species levels. In Stage 2, we determined the baseline condition of the species using the ecological requirements identified in Stage 1. We assessed the species’ historical and current condition in relation to the 3Rs and identified past and ongoing factors (beneficial and risk factors) that led to the species’ current condition. In Stage 3, we projected the likely future condition of the species using the baseline conditions established in Stage 2 and our predictions for future risk and beneficial factors.

For the purpose of this assessment, viability is broadly defined as the ability of the Fluted Kidneyshell to sustain its natural populations over time. A viable species must have a sufficient number and sufficient distribution of healthy, resilient populations to withstand stochastic disturbance and catastrophic events and sufficient ecological and genetic diversity to adapt to changing environmental conditions over time. Using the SSA framework, we consider what the

1 The species is referred to as P. subtentum in the Final Listing Rule (78 FR 59269). The most recent commonly accepted taxonomy is P. subtentus (Williams et al. 2017). SSA Report – Fluted Kidneyshell 1 February 2021

species needs to maintain viability by characterizing the historical, current, and future status of the species in terms of its resiliency, redundancy, and representation (Smith et al. 2018, entire).

Figure 1.1 Species Status Assessment Framework

Resiliency

Resiliency is assessed at the population level and is described as the ability of a species to withstand stochastic disturbance (arising from random factors). Resiliency is positively related to population size, growth rate, and fecundity and may be influenced by connectivity among populations. Generally, populations need sufficient numbers of individuals within habitats of adequate area and quality to maintain survival and reproduction in spite of disturbance. Resilient populations are more likely to withstand disturbances such as random fluctuations in birth rates (demographic stochasticity), variations in rainfall (environmental stochasticity), or the effects of anthropogenic activities.

Representation

Representation is assessed at the species level. It is described as the ability of a species to adapt to changing environmental conditions over time and is characterized by the breadth of genetic and environmental diversity within and among populations. The more representation, or diversity, a species has, the more capable it is to adapt to changes in its environment, whether caused by natural or anthropogenic factors. In the absence of species-specific genetic and ecological diversity information, we evaluate representation based on the extent and variability of habitat characteristics across the geographical range and other factors, as appropriate.

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Redundancy

Redundancy is assessed at the species level and is described as the ability of a species to withstand catastrophic events (a rare destructive natural event or episode involving many populations). A species is more likely to persist following devastating events if it has multiple resilient populations distributed across a large geographic area. Redundancy is measured by the number and distribution of resilient populations across the range of the species. The viability of a species increases as redundancy increases.

A range of conditions are used to characterize the species’ resiliency, redundancy, and representation (together, the 3Rs) to evaluate the current and future viability of the Fluted Kidneyshell. This SSA Report provides a thorough assessment of biology and natural history and assesses demographic risks, stressors, and limiting factors in the context of determining the viability and risks of extinction for the species. This document is a compilation of the best available scientific and commercial information and a description of past, present, and likely future risk factors to the Fluted Kidneyshell.

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INDIVIDUAL NEEDS: LIFE HISTORY AND BIOLOGY

This chapter provides the basic biological information regarding the taxonomy, description, life cycle, habitat, and environmental needs of the Fluted Kidneyshell.

2.1 Taxonomy

The Fluted Kidneyshell (Ptychobranchus subtentus (=subtentum)) (Figure 2.1) was originally described by Thomas Say as Unio subtentus (Say 1825). The species has several synonyms from other authors.

Unio subtentus Say, 1825; Say, 1825; Say, 1831; Say, 1858 Unio subtenta (Say, 1825); Deshayes, 1835 Margarita (Unio) subtentus (Say, 1825); Lea, 1836 Margaron (Unio) subtentus (Say, 1825); Lea, 1852 Medionidus subtentus (Say, 1825); Simpson, 1900 Ptychobranchus subtentus (Say 1825); Ortmann, 1912 Ptychobranchus subtentum (Say, 1825); Simpson, 1914 Unio subteritus (Say 1825); de Gregorio 1914 Unio subtontus (Say 1825); de Gregorio 1914 Unio subteritus [sic] var. purchreornatus (Say 1825); de Gregorio 1914 Unio subtontus [sic] var. pucheornatus (Say 1825); de Gregorio 1914 Ellipsaria subtenta (Say, 1825); Ortmann, 1918 Ptychobranchus (subtentus) subtentum (Say, 1825); Frierson, 1927 Ptychobranchus subtenta (Say 1825); Hickman, 1937 Ptychobranchus subtentus (Say 1825); Williams et al., 2017

Figure 2.1. Fluted Kidneyshell (Ptychobranchus subtentum (=subtentus)). Photo courtesy of Brett Ostby, Virginia Tech

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The current acceptable classification for the species follows (Integrated Taxonomic Information 2019; Williams et al. 2017):

Phylum: Mollusca Class: Bivalvia Order: Unionoida Family: Unionidae Subfamily: Ambleminae Tribe: Lampsilini Genus: Ptychobranchus Species: Ptychobranchus subtentus (Say, 1825)

2.2 Description

The following description of the Fluted Kidneyshell is taken from Parmalee and Bogan (1998, pp. 204–205) and Williams et al. (2008, p. 627). The Fluted Kidneyshell is a relatively large mussel that reaches about 13 centimeters (cm) (5 inches (in)) in length. The shape of the shell is roughly oval elongate, and the solid, relatively heavy valves (shells) are moderately inflated (Figure 2.2). A series of flutings (parallel ridges or grooves) characterizes the posterior slope of each valve. Shell texture is smooth and somewhat shiny in young specimens, becoming duller with age. Shell color is greenish yellow, becoming brownish with age, with several broken, wide green rays. Internally, there are two types of teeth, projections that keep the shell from being opened by external forces and are interlocking structures used to stabilize opposing shell halves. The pseudocardinal teeth (near the anterior end of the valve hinge line) are stumpy and triangular in shape. The lateral teeth (hinge teeth) are relatively heavy and nearly straight, with two in the left valve and one in the right valve. The color of the nacre (mother-of-pearl) is bluish-white to dull white with a wash of salmon in the older part of the shell (beak cavity).

Most anatomical features are tan or brown and vary from rusty orange to shades of reddish or grayish brown. Only a few select features will be detailed, but further information of soft anatomy is described by Williams et al. (2008, p. 627). The mantle is tan; the outside apertures vary from tan or brown, often rusty, and mottled with dark brown or grayish brown; the visceral mass (collective assemblage of internal organs) is pearly white to creamy white; the foot is creamy white to tan; and the gills are tan. The gills are only connected to the visceral mass anteriorly; the outer gills are marsupial, holding glochidia (larvae) in short folds when gravid.

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Figure 2.2. Fluted Kidneyshell valves. Photo credit: M. Compton.

2.3 Habitat

The Fluted Kidneyshell primarily occupies shoal habitat in small to large rivers (Williams et al. 2018, p. 628). It is typically found in substrates mixed with sand and gravel, and occasionally found near or under cobble and boulders that have smaller substrates near the margins. The species does not appear to do well in lentic habitats or areas with heavy deposits of fine material (Parmalee and Bogan 1998, p. 204-205; Williams et al. 2008, 628).

2.4 Feeding and Diet

The specific diet of the Fluted Kidneyshell is unknown but it is believed to obtain nutrients in a similar way to other mussel species. Mussels are generally omnivores and detritivores. Adults obtain their food primarily from filtering particles, such as bacteria, fine organic matter, phytoplankton and zooplankton, and dissolved organic matter, out of the water column. The particulate matter is primarily less than 20 μm in size (Gatenby et al. 1996, p. 606; Haag 2012, p. 26). The filter rate for some species can be up to 1 liter/hour/individual (Haag 2012, p. 28). Filter feeding also allows for oxygen uptake, waste excretion, and gamete dispersal and acquisition through the inhalant and exhalent apertures (Haag 2012, p. 27). The incurrent aperture has papillae, which serve as the first selection mechanism. Food material then enters the shell where cilia on the gills and palps move the matter to the mouth. Undesired material accumulates and is eventually discharged from the shell as pseudofeces (Haag 2012, p. 27). Mussels also obtain nutrients from deposit feeding (pedal feeding) (Yeager et al. 1994, p. 221; Haag 2012, p. 26). Instead of water entering through the incurrent aperture, cilia on the foot generate current to bring fine particulate organic matter within the sediments into the shell or cilia move particles along the foot into the shell, where they accumulate on the gills to be sorted, much like matter obtain through filter feeding (Haag 2012, p 26-28). This latter method, pedal feeding, is especially important for juvenile mussels that have not fully developed efficient filter

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feeding techniques but declines as the mussel develops during the first year (Haag 2012, p. 28). It has also been surmised that dissolved organic matter may be a significant source of nutrition for mussels (Vaughn et al. 2008, p. 411). Such an array of foods, containing essential long-chain fatty acids, sterols, amino acids, and other biochemical compounds, may be necessary to supply total nutritional needs (Strayer et al. 2004, p. 431).

2.5 Life History and Reproduction

Studies of the Fluted Kidneyshell have reported an estimated maximum age of 26 years (Davis and Layzer 2012, pp. 88-89) and 49 years (Henley et al. 2002, p. 19) among individuals sampled. Within its first year, growth can reach approximately 19 mm and another 5.5 mm each year for the next 5 years (Davis and Layzer 2012, p. 92). An individual can reach half its total length within its first 5-6 years. Older specimens, over 20 years in age, can approach and exceed 100 mm in length (Davis and Layzer 2012, p. 92). Davis and Layzer (2012, p. 88) encountered over 100 individuals in 2006 and estimated a female to male sex ratio as 1.9:1.

The unique life cycle of freshwater mussels relies on a parasitic symbiotic relationship with a host species (usually a fish) to complete the transformation from glochidia to juveniles (Figure 2.3).

Figure 2.3. Generalized life cycle of freshwater mussels.

Davis and Layzer (2012, p. 85) documented Fluted Kidneyshell spawning in the Clinch River, Tennessee, in late August (2005-2006), with water temperatures at around 24-26°C (75.2-78.8° F). During spawning, sexually mature males discharge gametes into the water column where a sexually mature female downstream will siphon the sperm through the incurrent aperture to fertilize the eggs (Haag 2012, p. 38). The precise location of fertilization is unknown for the

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Fluted Kidneyshell, but the female will brood the eggs in the primary water tubes of their marsupial gills (outer gills), which, like other members of the genus, are uniquely folded in a curtain-like fashion (McLeod et al. 2017, p. 339-340). In the Fluted Kidneyshell, a conglutinate (membranous capsule) develops around the glochidia that mimics or resembles the pupae of blackflies (Family Simulidae) (Barnhart et al. 2008, p. 377) (Fig. 2.4). Davis and Layzer (2012, p. 85) observed that the conglutinates had formed around the developed glochidia in approximately four weeks following fertilization (water temperatures ranging from 23-25° C (73.4-77° F)); and that approximately 500 glochidia (ranging from 166-915) were within each conglutinate (Davis and Layzer 2012, p. 86).

The Fluted Kidneyshell is a long-term brooder, and encased glochidia were observed inside the female from September into May of the following spring but absent by late June (Davis and Layzer 2012, p. 85-86). The number of conglutinates varies among individuals (85-329 per female, mean 208) and has a positive relationship with the size (length) of the mussel (Davis and Layzer 2012, p. 86). The conglutinates are released from the females and adhere to substrates along the stream bottom. The current will cause them to move and ‘wave’, which attracts unsuspecting fish. If a fish strikes the conglutinate, the enclosed glochidia are released and can attach to the gills of the fish. If the correct host fish strikes, the glochidia will encyst the gills of the host fish for further development.

In host trials, Davis and Layzer (2012, p. 86) infested Fantail and Rainbow darters from November 2005 through April 2006 with Fluted Kidneyshell glochidia. The duration of infestation (development) on the host fish varies based on species; Davis and Lazyer (2012, p. 88) indicated that Fluted Kidneyshell encystment lasted between 30-62 days, after which the fully developed glochidia drop off the fish and fall to the stream bottom to begin life at the juvenile stage in the life cycle. Juveniles will develop into adults in the same general location as the initial spot where they ‘dropped’ from their host fish. The precise age of sexual maturity in Fluted Kidneyshells is unknown and likely varies based on specific stream factors. Davis and Layzer (2012, p. 86, 89) encountered gravid females as small as 50 mm (estimated at 6-7 years old). The fecundity of females can be relatively high, and approximately 250,000 glochidia can be produced in a year (Davis and Layzer 2012, p. 91) but can range from approximately 43,000- 500,000 glochidia (Haag 2012, p 250).

The known fish host species for the Fluted Kidneyshell, through laboratory trials, are Banded Sculpin (Cottus carolinae), Rainbow Darter (Etheostoma caeruleum), Fantail Darter (Etheostoma flabellare), Barcheek Darter (Etheostoma obeyense), Redline Darter (Nothonotus rufilineatus), Bluebreast Darter (Nothonotus camurus), and Dusky Darter (Percina sciera) (Luo 1993, entire; Davis and Layzer 2012, pp. 86-88). All of the species listed are benthic insectivores.

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Figure 2.4. Fluted Kidneyshell conglutinates (Barnhart 2008).

Table 2.1. Overview of needs of Fluted Kidneyshell individuals based on our knowledge of the species’ biology, ecology, and life history. Resources and/or circumstances needed for Life Stage Resource Function Individuals to complete each life stage Fertilized Eggs ● Clean, flowing water* Breeding, Feeding (Late summer) ● Appropriate spawning temperatures (23-25° C (73.4-77° F)) ● Sexually mature males upstream of sexually mature females ● Adequate food source for brooding females Glochidia ● Clean, flowing water Breeding, Dispersal (Fall to early summer) ● Presence and abundance of healthy benthic host fishes Juveniles • Clean, flowing water Feeding, Shelter • Stable, appropriate substrates for settlement • Adequate food sources Adults • Clean, flowing water Feeding, Shelter • Stable, appropriate substrates and cover • Adequate food sources * Clean flowing water refers to the appropriate water temperature, salinity, and other water quality parameters needed for survival (Davis and Layzer 2012, entire, Williams et al. 2008, pp. 627-628).

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2.6 Population Needs

Each population of the Fluted Kidneyshell needs to be able to withstand, or be resilient to, stochastic events or disturbances. Even though these events may happen infrequently, they are reasonably likely to occur and can drastically alter Fluted Kidneyshell habitats where they happen. Examples of stochastic events include drought, major floods, fire, and landslides (Chapin et al. 2002 p. 285-288). To be resilient to stochastic events, populations of Fluted Kidneyshells need to have a large number of individuals (abundance), cover a large area (spatial extent), and be distributed in multiple non-linear waterways or watersheds (spatial complexity). Additionally, populations need to exist in locations where environmental conditions provide suitable habitat and water quality such that adequate numbers of individuals can be supported. Without all of these factors, a population has an increased likelihood for localized extirpation.

2.7 Species Needs

For a species to persist over time, it must exhibit attributes across its range that relate to representation and redundancy (Figure 2.5). Representation describes the ability of a species to adapt to changing environmental conditions over time and encompasses the “ecological and evolutionary patterns and processes that not only maintain but also generate species” (Shaffer and Stein 2000, p. 308). It is characterized by the breadth of genetic and environmental diversity within and among populations. For the Fluted Kidneyshell to exhibit adequate representation, resilient populations should occur in the ecoregions (EPA 2010, entire) to which it is native (i.e., Blue Ridge Mountain, Central Appalachian, Interior Plateau, Ridge and Valley, Southeastern Plains, Southwestern Plateau). These populations should occur at the widest extent possible across the historical range of the species, and they should occupy multiple tributaries in systems where they are native. The breadth of morphological, genetic, and behavioral variation should be preserved to maintain the evolutionary variation of the species. Finally, natural levels of connectivity should be maintained between representative populations because it allows for the exchange of novel and beneficial adaptations where connectivity is high or is the mechanism for localized adaption and variation where connectivity is lower or the species is naturally more isolated (Figure 2.5).

Redundancy describes the ability of a species to withstand catastrophic events. It “guards against irreplaceable loss of representation” (Redford et al. 2011, p. 42; Tear et al. 2005, p. 841) and minimizes the effect of localized extirpation on the range-wide persistence of a species (Shaffer and Stein 2000, p. 308). Redundancy for the Fluted Kidneyshell is characterized by having multiple, resilient and representative populations distributed within the species’ ecological setting and across its range. For this species to exhibit redundancy, it must have multiple resilient populations with connectivity maintained among them. Connectivity allows for immigration and emigration between populations and increases the likelihood of recolonization should a population become extirpated (Figure 2.5).

SSA Report – Fluted Kidneyshell 10 February 2021

Figure 2.5. How resiliency, representation, and redundancy are related to species viability.

2.8 Range and Distribution

The Fluted Kidneyshell is endemic to the Cumberland and Tennessee River drainages of the Ohio River basin and historically found in Alabama, Kentucky, Tennessee, and Virginia (Figure 2.6). In the Cumberland drainage, most records have come from the Upper Cumberland USGS 6-digit hydrological unit code (HUC6) drainage, in tributaries (e.g., Big South Fork Cumberland River, Buck Creek, and Rockcastle River) and in the mainstem below Cumberland Falls. In the Lower Cumberland River drainage, a single record occurs from the Harpeth River, but archeological accounts suggest it may have also occupied the mainstem and other tributaries (Parmalee and Bogan 1998, p. 204-205; Haag and Cicerello 2016, p. 214-15). In the Tennessee River drainage, the species primarily occurred in headwater tributaries in Virginia and Tennessee (e.g., Nolichucky, Holston, Clinch, Powell Rivers) and in a few western tributaries of the lower Tennessee River (e.g., Duck and Elk Rivers).

The current range was determined based on the compilation of available data from state heritage databases, museum records, and survey reports. Archeological accounts were not used to delineate populations, because, while highly suggestive, they do not definitively associate the

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species to a particular watershed (Haag and Cicerello 2016, p. 30-31). An occurrence was considered current (extant) if at least one fresh dead or one live specimen was reported from 2004 to 2018. Accounts prior to 2004 were considered historical. Many of the records did not give a precise location in a watershed. For this reason, we did not create dot maps representing the species’ occurrence. We divided the records into populations using the USGS 8-digit hydrological unit code (HUC8) designations (Table 2.2) (Figure 2.6). In the absence of a population genetic study, HUC8s were used to provide a consistent framework at an appropriate scale to capture the distribution of the species for assessment purposes. Furthermore, the HUC8s were often associated with impoundments which would limit or prohibit the exchange of individuals and genetics. In chapter 4, we indicate USGS 10-digit hydrological unit code (HUC10) occupancy within those populations.

Table 2.2. Designated populations of the Fluted Kidneyshell within the Cumberland and Tennessee River drainages. Populations indicated in bold are extant. Drainage Population HUC8 Cumberland Harpeth 05130204 Obey 05130105 Buck Creek 05130103 Big South Fork 05130104 Rockcastle 05130102 Upper Cumberland 05130101 Tennessee Upper Duck* 06040002 Buffalo 06040004 Pickwick Lake 06030005 Lower Elk* 06030004 Upper Elk 06030003 Wheeler Lake 06030002 Guntersville Lake 06030001 Lower French Broad 06010107 Nolichucky* 06010108 Holston 06010104 North Fork Holston 06010101 South Fork Holston 06010102 Clinch 06010205 Powell 06010206 * Reintroduced populations

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Figure 2.6. Fluted Kidneyshell populations (HUC8s).

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FACTORS INFLUENCING VIABILITY

Fluted Kidneyshell populations are susceptible to numerous natural and anthropogenic stressors and threats that occur within their watersheds. As discussed in the previous chapter, to remain resilient, Fluted Kidneyshell populations need suitable and stable water quality and habitat quality, as well as good connectivity within and among populations to allow for gene flow. Stressors and threats can influence one or more of these needs, and the degree to which they influence the habitat factors can vary across the range of the species. Habitat factors influence the demographic factors of a population, such as growth and recruitment. Demographic factors in healthy populations can offset and mitigate some effects of threats, but the current and potential extent and magnitude of the threats influence viability. Conservation measures (e.g., riparian buffers, propagation) and regulatory management can mitigate negative effects to increase the resiliency of a population, or the redundancy and representation of the species across its range, thus increasing viability.

This chapter will focus on the primary factors that influence water quality, habitat quality, and habitat connectivity associated with Fluted Kidneyshell populations. Some factors, such as disease or overutilization for commercial and scientific purposes are not discussed, because of a dearth of information related to the Fluted Kidneyshell or a minimal likelihood of occurrence and influence.

Water Quality Degradation

Water quality is an essential factor for the persistence of Fluted Kidneyshell populations. Urban, agriculture, and resource extraction landuse practices, as well as stochastic events, produce numerous point source and non-point source threats to water quality, which can negatively influence aquatic life, including freshwater mussels.

Water quality is degraded when contaminants, such as heavy metals, ammonia, chlorine, pesticides, and other compounds reach a concentration that is above background levels and adversely affect aquatic life. The effects of heavy metals, ammonia, pesticides, and other contaminants on freshwater mussels were reviewed by Mellinger (1972, entire), Fuller (1974, entire), Havlik and Marking (1987, entire), Naimo (1995, entire), Keller and Lydy (1997, entire), and Newton et al. (2003, entire). These findings, in general, indicate mussels are highly sensitive to water quality degradation, and water quality criteria might not be adequate to protect them (Keller and Lydy 1997, entire; Augspurger et al., 2003; Wang et al. 2008, entire). Furthermore, it has been reported that glochidia and juvenile mussels are especially susceptible to contaminants (Augspurger et al. 2003, p. 2,571; Bartsch et al. 2003, p. 2,566; Bringolf et al. 2010, entire; Gibson et al. 2018, entire).

The effects of many specific water quality degradation threats on the Fluted Kidneyshell, and other freshwater mussel species, are poorly understood. Below, we discuss some common contaminants within the historical range of the species that degrade water quality for aquatic life in general, and, when the information is available, we discuss how freshwater mussels may be affected.

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Heavy Metals

Heavy metals, such as copper, lead, mercury, and manganese, commonly enter stream systems through industrial point sources and mining effluents. The impact of heavy metals on mussels can be detrimental and long-lasting. Long-term declines and extirpation of mussels from the Clinch River in Virginia have been attributed to copper and zinc contamination in wastewater, originating from an electric power plant in Carbo, Virginia (Ahlstedt et al. 2017, p. 221). Despite plant improvements (Ahlstedt et al. 2017, p. 221), the metals remain in sediments, which can affect mussel recruitment and densities for decades (Price et al. 2014, p. 12; Zipper et al. 2014, p. 9). Gibson et al. (2018, entire) looked at a suite of parameters, such as nickel, zinc, and potassium, and determined that the tested native mussels were extremely sensitive to these metals and more sensitive than existing water quality criteria. Gibson et al. (2018, entire) recommended that existing water quality criteria be refined to adequately protect native mussels, and that new criteria be established for parameters that currently lack criteria. Juvenile mussels are especially affected because they readily ingest contaminants that are adhered to sediment particles while pedal feeding (Newton and Cope 2007, p. 276). Heavy metal contaminants can also affect mussel glochidia, which are sensitive to some toxicants (Goudreau et al. 1993, p. 221; Jacobson et al. 1997, p. 2,386; Valenti et al. 2005, p. 1,243). Even at low concentration, heavy metals adversely affect mussels and may inhibit glochidia attachment to fish hosts (Havlik and Marking 1987, p. 4).

Cadmium appears to be the most severe heavy metal contaminant to mussels (Havlik and Marking 1987, pp. 4–9), and chromium, copper, mercury, and zinc have also been documented to negatively affect biological processes (Naimo 1995, p. 355; Jacobson et al. 1997, p. 2389; Valenti et al. 2005, p. 1243). Manganese from coal mine waste can also adversely impact mussels and has been negatively correlated with mussel survival and biomass (Archambault et al. 2017, p. 402). Shell concentrations of manganese were observed in the Muskingum River, Ohio where the metal was potentially assimilated by mussels as a replacement of calcium during growth (Havlik and Marking 1987, p. 8).

Endocrine Disruptors

Endocrine disrupting compounds (EDCs) are chemicals, such as pharmaceutical drugs, pesticides, nonionic surfactants, environmental pollutants, plastics, and some naturally produced botanical chemicals, that are becoming more common within aquatic systems (Gagne et al. 2001, entire; Fent et al. 2006, entire). Effluent from municipal waste water treatment plants, runoff from livestock operations, industrial discharges, and runoff or leaching of pesticides into groundwater or surface waters are primary sources of EDC input. These chemicals interfere with the normal endocrine or reproductive function of an organism by mimicking natural hormones or stopping the production or function of hormones. The impacts of EDCs on mussels is not fully understood, but reproduction malfunctions have been observed, and chronic exposure to estrogenic compounds have caused feminization in male mussels downstream of effluents (Gagne et al. 2011, entire). Pharmaceutical fluoxetine, an active ingredient in some anti- depressant medications, was identified as potentially disrupting mussel reproduction by inducing gamete release in males and stimulating lure display in females (Bringolf et al. 2010, entire). Pesticides, such as atrazine, have altered mussel movement and aggregation behavior in mussels

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(Flynn and Spellman 2009, entire). No research with EDC’s has been conducted specifically on Fluted Kidneyshell, but populations are likely exposed to numerous sources, such as sewage effluents, livestock operations, and other agriculture practices that exist within their range. Atrazine was reported from 75 percent of the stream surface water and 40 percent of the groundwater in the agricultural region of the United States (Wu et al. 2010, entire).

Nutrient and Organic Pollution

Nutrient and organic enrichment into waterbodies is a widespread and common impact across the range of the Fluted Kidneyshell. The sources of nutrient enrichment can vary, but are often associated with urban and agricultural practices; specific sources can include municipal wastewater treatment plants, urban runoff, confined animal feeding operations (CAFO), and non- point source inputs. Approximately 3,200 km (2,000 miles) of stream in Kentucky (KDEP 2014, p. 62) and Tennessee (TDEC 2014, p. 60) are impaired because of nutrient enrichment, organic enrichment, and/or low dissolved oxygen. Listed sources of these impairments include livestock, municipal wastewater treatment plants, urban runoff, and improper application of fertilizers (TDEC 2014, p. 50). If fertilizers are not applied properly and at the right time of the year, they can affect water quality in the stream systems. Stream bank instability from agricultural clearing and lack of cover crops between rotations on farmed lands can increase the amount of nutrients that enter nearby streams by way of increased soil erosion (cover crops and other vegetation will use excess nutrients and increase soil stability) (Barling and Moore 1994, p. 543). Livestock often use streams or artificial ponds installed in a stream as a water source, which degrades water quality, contributes to bank instability, and reduces water quantity available for aquatic fauna that may occur downstream.

Excessive nutrient input may cause algal blooms in surface waters (Carpenter et al. 1998, entire). This excessive algal growth can alter and smother benthic stream substrates (Cooper 1993, p. 405), which may potentially limit available habitat for the Fluted Kidneyshell. In addition, the increased organic matter and nutrient load increases the biological oxygen demand (BOD) and lowers the dissolved oxygen within a system. Chronic BOD situations could stress mussel populations, which need highly oxygenated waters. In addition, the bacterial nitrification process of ammonia decreases as oxygen levels decrease (Haag 2012, entire). This is concerning because un-ionized ammonia (NH3), which is more toxic to mussels, especially in early life stages, is broken down by nitrifying bacteria into the less toxic nitrates (NH4) (Newton 2003, p. 2543).

Ammonia occurs naturally as a waste product of aquatic organisms and decomposition of organic nitrogen, but excess nutrient input can cause increases and spikes in ammonia concentrations in streams directly or indirectly, as previous mentioned with the disruption of the bacterial nitrification process. Ammonia directly enters a system from nitrogenous fertilizers and animal waste in agricultural settings, from effluents of outdated or poorly treated waste water from municipalities, and from industrial waste products (Goudreau et al. 1993, p. 222; Augspurger et al. 2003, p. 2575; Newton 2003, p. 2543).

Ammonia is one of the most toxic contaminants to mussels, even at low concentrations. Augspurger et al. (2003, p. 2571-2572) indicated that the mean acute values at the genus level

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for mussels ranged from 2.56–8.97 mg/L total ammonia as nitrogen, normalized to pH 8, which were at the sensitive range of the genus mean acute values. Furthermore, glochidia were two to four times more sensitive for three of the genera in which comparison could be made between glochidia and juveniles (Augspurger et al. 2003, p. 2571). The overall effect of toxic ammonia concentrations on bivalves include reduced survival, reduced growth, and reduced reproduction (Strayer and Malcom 2012, p. 1786; Augspurger et al. 2003, p. 2575; Mummert et al. 2003, p. 2522). In addition, ammonia has also been shown to cause a shift in glucose metabolism and alter the metabolic use of total lipids, phospholipids, and cholesterol in mussels (Chetty and Indira 1994, p. 693). The toxic effects of ammonia are more pronounced at higher pH and water temperature, because the level of the un-ionized form increases as a percentage of total ammonia (Mummert et al. 2003, p. 2,545; Newton 2003, p. 2544). Therefore, this contaminant may become more problematic for juvenile mussels during low flow, high temperature periods (Cherry et al. 2005, p. 378). Ammonia is especially concerning in the sediment of streams. Ammonia concentrations are greatest in the interstitial spaces of the substrates, where juvenile mussels live and feed, and the concentrations may exceed water quality standards (Frazier et al. 1996, p. 97; Cooper et al. 2005, p. 392). Ammonia is considered a limiting factor for survival and recovery of some mussel populations due to its high level of toxicity and because the highest concentrations occur in their microhabitats (Augspurger et al. 2003, p. 2569).

Other Contaminants

Other common contaminants associated with households and urban areas, particularly those from industrial and municipal effluents, may include heavy metals, chlorine, phosphorus, and numerous other toxic compounds. Pharmaceuticals, hormones, and other organic wastewater contaminants (OWCs) were detected downstream from urban areas and livestock production (Kolpin et al. 2002, p. 1208). These OWCs (82 of the 95 tested for) originated from a wide range of residential, industrial, and agricultural sources, and some are known to have deleterious effects on aquatic organisms (Kolpin et al. 2002, p. 1210). Wastewater is discharged through National Pollutant Discharge Elimination System (NPDES)-permitted (and some non-permitted) sites throughout the country. In the upper Tennessee River basin, high counts of coliform bacteria originating from wastewater treatment plants have been documented, and degradation of water quality is a primary threat to aquatic fauna this system (Neves and Angermeier 1990, p. 50).

Extraction of petroleum produces waste water with high chlorine concentrations, to which all stages of freshwater mussels are highly sensitive (Patnode et al. 2015, p. 56). Land-based oil and gas drilling activities may have adversely affected mussels, including the Fluted Kidneyshell, in the Cumberland River drainage (Haag and Warren 2004, entire; Ahstedt et al. 2014, entire; Haag and Cicerello 2016, p. 214-215).

Exposure to pollutants through stochastic events, such as chemical spills, could be devastating to the Fluted Kidneyshell because their fragmented distribution (i.e., isolated populations), and limited mobility decreases their potential for recolonization (Wheeler et al. 2005, p. 155). Numerous streams throughout the range of the Fluted Kidneyshell have experienced mussel and fish kills from toxic chemical spills, including multiple spills within the Clinch River, Tennessee and Virginia. The species has been able to withstand such events in the Clinch River, and that

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population remains the largest across the species’ range. However, sediment from the Clinch River was found to be toxic to juvenile mussels, which has contributed to the decline and lack of recruitment of mussels in the Virginia portion of the river, suggesting lasting effects of these spills on aquatic species habitat (Ahlstedt and Tuberville 1997, p. 74; Price et al. 2014, p. 855). The risk of chemical spills continues to be high across the Fluted Kidneyshell’s range, while the subtle, chronic, low-level effect of pervasive containments in a system may contribute substantially to widespread decreases in mussel density and diversity (Naimo 1995, p. 354).

Habitat Degradation

The effects of specific habitat degradation threats on the Fluted Kidneyshell, and other freshwater mussel species, is poorly understood. Below, we discuss some common threats to habitat within the historical range of the species that degrade habitat for aquatic species in general. While large impoundments for reservoirs have undoubtedly had devastating, persistent effects to Fluted Kidneyshell populations, we do not have information to conclude which other potential threats pose significant population-level threats to the species.

Impoundments and Barriers

Connectivity among populations and among suitable habitats is important for the persistence of a species. Habitat fragmentation limits dispersal and recruitment and contributes to genetic isolation (Strayer 2008, entire). Connected populations have a greater capability to adapt to changing environmental conditions (Haag 2012, entire) and maintain an effective population size. Isolated populations are more susceptible to stochastic events, demographic stochasticity, and localized environmental degradation (Yan et al. 2011, entire; Haag 2012, p. 336). Therefore, a single weather event, chemical spill, or habitat alteration is more likely to cause local extirpation. Dams, road crossing and other barriers, and environmental degradation rendering reaches of stream unsuitable are common threats to habitat connectivity.

Dams were constructed for many purposes, such as for flood prevention, water storage, electricity generation, irrigation, recreation, and navigation (Eissa and Zaki 2011, p. 253). Their profound negative effects on riverine habitat and native aquatic life are well-documented (e.g., Guenther and Spacie 2006, entire; Haag 2012, pp. 328-334; Haag and Cicrello 2016, p. 214-215; Hayes et al. 2006, entire; Watters 2000, entire; Winston et al. 1991, entire). The extinction/extirpation of many North American freshwater mussel species can be traced to impoundments in all major river basins of the central and eastern U.S. (Haag 2009, entire). Reductions in the diversity and abundance of mussels are primarily attributed to habitat shifts caused by impoundments (Neves et al. 1997, p. 63). In addition to the physical barrier presented by the dam itself, a dam’s effects on stream flow influence habitat suitability for mussels, like Fluted Kidneyshell, and their host fishes. Dams drastically alter the upstream habitat from shallow, highly oxygenated flowing water to deeper, less oxygenated standing water. Water impounded in smaller reservoirs is typically warmer than the free-flowing streams, while water impounded in larger reservoirs is stratified with warm surface waters overlaying colder water. The species richness of the fauna decreases in these converted habitats. Downstream habitat

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experiences fluctuations in flow regimes (minimal releases and scouring releases), seasonal depletion of dissolved oxygen, and changes in water temperatures.

There are approximately 2,500 dams of various sizes directly or indirectly impacting nearly the entire range of the Fluted Kidneyshell (TVA 2020; USACE 2019); some of the most prominent structures are listed below with the river the dam impounded and its date of completion:

● Wolf Creek Dam – Cumberland River (Kentucky), 1951 ● Dale Hollow Dam – Obey River (Tennessee), 1943 ● Normandy Dam – Duck River (Tennessee), 1976 ● Tims Ford Dam – Elk River (Tennessee), 1970 ● Pickwick Dam – Tennessee River (Tennessee), 1938 ● Wheeler Dam – Tennessee River (Alabama), 1936 ● Guntersville Dam – Tennessee River (Alabama), 1939 ● Norris Dam – Clinch and Powell Rivers (Tennessee), 1936 ● Cherokee Dam – Holston River (Tennessee), 1941 ● Douglas Dam – French Broad River (Tennessee), 1943 ● Nolichucky Dam – Nolichucky River (Tennessee), 1913

The dams within the range of the Fluted Kidneyshell have isolated populations and altered the habitat, flow, and temperature regimes upstream and downstream of populations. The Wolf Creek Dam (Lake Cumberland) in Kentucky completely transformed the middle Cumberland River drainage, resulting in a loss of approximately 50 percent of the riverine mussel fauna (Haag and Cicerello 2016, pp. 14, 52). Impoundments within the South Fork Holston River (Tennessee) were identified as the biggest contributor to the decline in diversity and abundance of the native mussel fauna (Parmalee and Polhemus 2004, p. 231). The Cherokee Dam in the lower mainstem of the Holston River, Tennessee, resulted in the extirpation of approximately 75 percent of the native mussel fauna downstream of the dam (Parmalee and Faust 2006, entire). Norris Dam, which impounds the lower reaches of the Clinch and Powell Rivers, isolates the best remaining population of Fluted Kidneyshell in the Clinch River from all of the other populations within its range, putting that population at risk by minimizing potential immigration and genetic exchange from other populations. The series of dams on the Tennessee River in Alabama inundated the location of the greatest known mussel diversity in the world (Haag 2012, p. 319-323).

Other barriers associated with road crossings can sever stream connectivity. Poorly or improperly installed bridges and culverts can alter the flow regime to a point to where fish passage is not possible or unlikely. The stream channel can become scoured downstream and lead to culvert or bridge abutments being perched, making fish passage impossible or only feasible during high-water events. Although these crossing are smaller in scale, the barriers add another level of fragmentation within a stream system. Most of these smaller barriers occur in streams that are likely too small to support Fluted Kidneyshell, but could potentially affect host fish populations.

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Sedimentation

Sedimentation is frequently noted as a cause of habitat degradation and stream impairment. Excessive stream sedimentation (or siltation) is the accumulation of substrate particles (e.g., silt and sand) when the sediment load is greater than the rate of sediment transportation (Mugade and Sapkale 2015, entire). The sediment load into a stream is typically the result of landuse activities, such as agriculture, urban, forestry, mining, or development in general, as well as instream alterations caused by dredging, dams, road and pipeline crossings, or other infrastructures. These activities often remove the riparian vegetation and destabilize the stream channel, which increases the erosion potential and increases the sediment load. Locally, excessive sediments will accumulate and cover the stream channel and fill the interstitial spaces with finer substrates, homogenizing and decreasing the available habitat. Extreme situations of sedimentation will completely, or nearly, cover larger substrates, such as cobble and boulders. Furthermore, sedimentation also increases stream turbidity, reduces light penetration, reduces water depth, and increases temperature (Waters 1995, pp. 67–69, 118). Though clear correlations have not been documented, excessive sedimentation could potentially affect Fluted Kidneyshell populations by disrupting the fish host relationship through several mechanisms: loss of host fish prey and habitat, reduced visibility of lures/conglutinates, and decreased substrates for adherence of conglutinates (Brim Box and Mossa 1999, entire; Berkman and Rabeni 1987, 291–293; Messinger and Chambers 2001, p. 50–51; Sutherland et al. 2002, entire; McGinley et al. 2013, pp. 223–226). However, Strayer and Malcolm (2012, p. 1785) did not find a correlation between fine sediments and freshwater mussel recruitment. Though frequently cited as a threat to mussels, studies have presented conflicting results about the role of increased sedimentation on the decline of mussel populations; additional studies are needed to better understand its effects (Haag 2020, pers. comm.).

Channel Alteration and Gravel Mining

Stream channelization is usually conducted under the perceived benefit that it will improve drainage. Channels are widened, straightened, and deepened, and riparian vegetation is often removed (Brooker 1985, p. 63). These activities result in accelerated and increased erosion of the stream channel, which destabilizes the channel and reduces habitat availability (Hartfield 1993, p. 131; Hubbard et al. 1993, pp. 136-145). Furthermore, channelization often results in loss of stream length, which contributes to more variable hydrographs where higher peak flows occur during rain events and lower base flows occur during dry periods (Brooker 1985, p. 63).

Like stream channelization, instream gravel mining results in stream channel modifications that alter flow patterns, increase erosion and sediment load and transport, and decrease available habitat and water quality (Kanehl and Lyons 1992, pp. 26-27; Roell 1999, entire). In addition, water quality effects from gravel mining include increased turbidity, reduced light penetration, increased temperature, and increased sedimentation.

The degradation of habitat and subsequent decreased water quality from these intrusive activities have a detrimental effect on aquatic life. These habitat and water quality degradations reduce macroinvertebrate and fish populations, which suffer impacts to spawning and nursery habitat, and food web disruptions (Kondolf 1997, p. 541; Brown et al. 1998, p. 988). Unfortunately, the

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alteration of the stream channels is a common practice within the range of the Fluted Kidneyshell, which needs stable channels and a mix of substrate sizes. The U.S. Army Corps of Engineers and state water quality agencies regulate activities within streams and rivers, but often stream alterations and gravel mining go unmonitored and are only sporadically detected when field surveys for different purposes are conducted. In Kentucky, channelization has been identified as a source of impairment for 1,112 km (691 mi.) of stream, and loss of riparian habitat has been identified as a source of impairment for almost 2,837 km (1,763 mi.) (KDEP 2014, p. 66). In Tennessee, 5,686 km (3,533 mi.) of stream are impaired because of channelization, 4,865 km (3,023 mi.) are impaired due to riparian habitat removal, and 10,029 km (6,232 mi.) are impaired due to grazing in riparian areas (TDEC 2014, pp. 63-64). Gravel mining continues to occur in Buck Creek, Kentucky, which contains one of the few remaining Fluted Kidneyshell populations within Cumberland River drainage (Schuster et al. 1989, p. 84; Hagman 2000, p. 40; Haag and Cicerello 2016, p. 214-215).

Climate Change

Changes in water temperature, precipitation patterns, and salinity levels can influence freshwater mussels (Nobles and Zhang 2011 pp. 147–148). It is anticipated that the number of days with heavy precipitation over the next 25 to 35 years will increase within the range of the Fluted Kidneyshell (US Global Climate Change Research Program 2017, p. 207). Poff et al. (2002, pp. ii–v) identified several potential impacts of climate change on aquatic systems which include:

● Increases in water temperatures that may alter fundamental ecological processes, thermal suitability of aquatic habitats for resident species, and their geographic distribution, thus increasing the likelihood of species extinction and loss of biodiversity. ● Changes and shifts in seasonal patterns of precipitation and runoff, which can alter the hydrology of stream systems, affecting species composition and ecosystem productivity. Aquatic organisms are sensitive to changes in frequency, duration, and timing of extreme precipitation events such as floods or droughts, potentially resulting in interference of reproduction. Further, increased water temperatures and seasonally reduced streamflow can alter many ecosystem processes, including increases in nuisance algal blooms. ● Cumulative or synergistic impacts that can occur when considering how climate change may be an additional stressor to sensitive freshwater systems, which are already adversely affected by a variety of other human impacts, such as altered flow regimes and deterioration of water quality. ● Adapting to climate change may be limited for some aquatic species depending on their life history characteristics and resource needs. Reducing the likelihood of significant impacts would largely depend on human activities that reduce other sources of ecosystem stress to ultimately enhance adaptive capacity, which could include, but not be limited to: maintaining riparian forests, reducing nutrient loading, restoring damaged ecosystems, minimizing groundwater and stream withdrawal, and strategically locating any new reservoirs to minimize adverse effects. ● Changes in presence or combinations of native and nonnative, invasive species could result in specific ecological responses to changing climate conditions that cannot be easily predicted at this time. These types of changes (e.g., increased temperatures that are

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more favorable to a nonnative, invasive species compared to a native species) can result in novel interactions or situations that may necessitate adaptive management strategies. ● Shifts in mussel community structure, which can stem from climate-induced changes in water temperatures since sedentary freshwater mussels have limited refugia from disturbances such as droughts and floods, and since they are thermo-conformers whose physiological processes are constrained by water temperature within species-specific thermal preferences (Galbraith et al. 2010, p. 1,176).

The precise magnitude, timing, frequency, and extent of the effects of climate change on Fluted Kidneyshell populations are difficult to predict. The greatest concerns are alterations to the natural flow regime and temperature regime, which are important factors needed for the Fluted Kidneyshell to persist. Davis and Layzer (2012, entire) indicated that glochidia development occurred within a short period of time and within a narrow range of temperatures. Alterations to these vital regimes could negatively influence Fluted Kidneyshell recruitment and survival.

Invasive Species

Approximately 42 percent of Federally Threatened or Endangered species are significantly impacted by nonnative, nuisance species across the nation, and these nuisance species are significantly impeding recovery efforts (NCANSMP 2015, pp. 8–9). Although only about 15 percent of nonnative species become successfully invasive after colonizing their new environment (Simberloff 1996, entire), established nonnative species can have several advantages in outcompeting native species for space, food, light, and other resources. Invasive species tend to easily adapt to varying environments and have a greater tolerance to living conditions that allow them to thrive. Native predators may not exist to regulate the nonnative species; therefore, invasive species can potentially live longer and reproduce more often, increasing competition on the native fauna. Invasive species may prey on native species or carry diseases that are harmful to native species.

Many invasive species have wreaked havoc on aquatic ecosystems and native species in North American waterbodies, such as zebra mussel (Dreissena polymorpha), Quagga mussel (Dreissena bugenis), black carp (Mylopharyngodon piceus), silver carp (Hypophthalmichthys nobilis), bighead carp (Hypophthalmichthys nobilis), rock snot (a.k.a. didymo; Didymosphenia geminata), hydrilla (a.k.a. waterthyme; Hydrilla verticillata), and the Asian clam (Corbicula fluminea). Hydrilla and the Asian Clam have overlapping distributions with Fluted Kidneyshell and occupy similar habitats. In the Duck River, Asian Carp have been observed up to Lillards Mill (DRM 179.2) (Hubbs 2019, pers. comm.).

Hydrilla is an aquatic plant that alters stream habitat, decreases flows, and contributes to sediment buildup in streams (NCANSMP 2015, p. 61). High sedimentation can cause suffocation, reduce stream flow, and impede mussels’ necessary interactions with host fish. Hydrilla can quickly dominate native vegetation, forming dense mats at the surface of the water and dramatically altering the balance of the aquatic ecosystem. Hydrilla covers spawning areas for native fish and can cause significant reductions in stream oxygen levels (Colle et al. 1987, p. 410). Hydrilla is widespread in the Cumberland and Tennessee River drainages.

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The Asian clam is a small bivalve with several life history traits allowing it to colonize habitats quickly and maintain abundant populations: hermaphroditism, fast growth, early maturity (3-6 months), biannual larval release, likely ability to self-fertilize, and non-reliance on fish hosts (McMahon and Bogan 2001, entire; Cherry et al. 2005, entire). The Asian Clam is present in nearly every stream system throughout the range of the Fluted Kidneyshell and has been negatively correlated with Fluted Kidneyshell juvenile mussel growth in the Rockcastle River system (Haag 2020, pers. comm.). Asian Clams alter benthic substrates, compete with native species for limited resources, and cause ammonia spikes in surrounding water when they die off in large numbers (Scheller 1997, p. 2). When an Asian Clam die off occurs, accompanying dissolved oxygen level decreases and ammonia increases can cause stress and mortality to the Fluted Kidneyshell (Cherry et al. 2005, p. 377). Population densities can vary greatly from 100- 200 individuals per square meter to exceeding 10,000 individuals per square meter (Haag 2012, entire). The specific effect and mechanisms of Asian Clams on native mussels is poorly understood, but recent research in Europe found a correlation between greater Asian Clam densities and lower growth, lower physiological condition, and greater locomotor activity in a native species, Unio delphinus, (Ferreira-Rodriguez et al. 2018). In Kentucky, current research is investigating the growth of juvenile native mussels in relation to Asian Clam abundance and food availability (Haag 2019, pers. comm.,).

Impervious Surfaces

Development of the landscape can alter water quality, water quantity, and habitat (both in-stream and streamside) (Ren et al. 2003, p. 649; Wilson 2015, p. 424). A substantial artifact of urban development is the increase of impervious surfaces within a watershed. Impervious surfaces are all hard surfaces, such as roads, building footprints, parking lots, and highly compacted soils that alter the natural path of rainwater. The streamflow in urban settings becomes more variable and dependent on localized rain events, because impervious surfaces prevent or alter the natural recharge of the groundwater table across the landscape, which ultimately and gradually seeps into streams (Brabec et al. 2002, p. 499). Instead, the extent and volume of water entering a stream associated with storm events increases and the duration that water travels over the landscape before entering the stream decreases (Giddings et al. 2009, p.1). Pollutants (e.g., gasoline, oil drips, and fertilizers) that accumulate on impervious surfaces are washed directly into streams during storm events (USGS 2014, pp. 2-5). During warm weather, rain that falls on impervious surfaces becomes superheated and can stress or kill freshwater species when it enters streams (USGS 2014, pp. 2-5). As little as 10 percent impervious cover in a watershed can modify hydrographs, resulting in erosion, channel instability and widening, substrate alteration, and in-stream and riparian habitat loss (Booth and Jackson 1997, p. 1084). Within the range of the Fluted Kidneyshell, rapid commercial and residential development is leading to increased areas of impervious surfaces in parts of the Tennessee and Cumberland River watersheds, (TDEC 2014, p. 62).

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Undefined Threats

As discussed at the beginning of section 3, the threats to the Fluted Kidneyshell, and other freshwater mussels are poorly understood. A number of streams have experienced “enigmatic declines” in their mussel fauna since the 1960s, including several within the historical range of the Fluted Kidneyshell (e.g, Rockcastle River, Horse Lick Creek, Buck Creek, Little South Fork Cumberland River, the Cumberland River) (Haag 2019, entire). These declines have been similar in that they were relatively rapid (within about 10 years), affected all species of mussels but not other aquatic taxa, and appear to have specifically affected recruitment (Haag 2019, p. 45-48). The cause of these enigmatic declines has not been identified.

Multiple mussel species, including Fluted Kidneyshell, within the Clinch River have experienced die-offs that, unlike the enigmatic declines discussed in the paragraph above, affect individuals across all size classes. The first observed die-off was in June 2016 at Kyles Ford and Frost Ford in the Clinch River, Tennessee (Richard 2019, pers. comm.). Similar mortality events were observed again during the late summer to early fall in 2017, 2018, and 2019 (Richard 2019, pers. comm.). Research suggests that pathogens or other causal agent (i.e., bacteria, parasites) contributed poor health of these mussel in the Clinch River beginning in 2016 leading to the mussel die-off (Henley et al. 2019, pp. 691-694). Richard et al. (2020, entire) identified a novel densovirus (Clinch densovirus 1) that was epidemiologically linked to morbidity in the Clinch River mussels.

Regulatory Mechanisms and Conservation Efforts

Existing Regulatory Mechanisms and Programs

The Fluted Kidneyshell is currently listed as a federally endangered species and is afforded protections under the Endangered Species Act of 1973 (Act), as amended (16 U.S.C. 1531 et seq.). Section 7 of the Act requires Federal agencies to consult with the Service on any action that may affect a listed species or any action that may destroy or adversely modify critical habitat. Section 9 of the Act provides protection against “take” of the species (“take” means to harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect or attempt to engage in any such conduct).

The species is listed as endangered in Kentucky (KNP 2019, p. 12), Tennessee (TWRA 2015, p. 304), and Virginia (VDGIF 2020, p. 3). In Kentucky, no legal protections are afforded state listed species or its habitat. In Tennessee, under the Tennessee Nongame and Endangered or Threatened Wildlife Species Conservation Act of 1974 (Tennessee Code Annotated §§ 70-8- 101-112) “it is unlawful for any person to take, attempt to take, possess, transport, export, process, sell or offer for sale or ship nongame wildlife, or for any common or contract carrier knowingly to transport or receive for shipment nongame wildlife.” Further, regulations included in the Tennessee Wildlife Resources Commission Proclamation 00-14 (Wildlife in Need of Management) (1) prohibits the knowing destruction of habitat of designated species without authorization and (2) provides circumstances for which permits can be given to take, posses, transport, export, ship, remove, capture, or destroy a designated species. In Virginia, the Virginia Endangered Species Act of 1987 (Virginia Code Annotated §§ 29.1-563 – 570)

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prohibits the taking, transportation, possession, sale, or effort for sale within the Commonwealth of any threatened or endangered species listed by the United States Secretary of the Interior pursuant of the Endangered Species Act.

The Fluted Kidneyshell and its habitats are afforded some protection from water quality and habitat degradation under the Clean Water Act, Surface Mining Control and Reclamation Act of 1977 (30 U.S.C. 1234–1328), Kentucky’s Forest Conservation Act of 1998 (KRS §§149.330– 355), Kentucky’s Agriculture Water Quality Act of 1994 (KRS §§ 224.71–140), Kentucky Wild Rivers Act (KRS §§146.200-360), additional Kentucky statutes and regulations regarding natural resources and environmental protection (KRS § 224; 401 KAR §§ 5:026, 5:031), Tennessee Nongame and Endangered or Threatened Wildlife Species Conservation Act of 1974, and Tennessee’s Water Quality Control Act of 1977 (T.C.A. 69–3–101). In general, these existing regulations are designed to maintain and protect the integrity of waterbodies for aquatic life and human use by overseeing the pollution input into the systems. For example, in Kentucky, streams supporting federally threatened or endangered species receive additional protection under Kentucky’s water quality standards. Pursuant to 401 KAR §§ 10:031, Section 8, the existing water quality and habitat of these Outstanding State Resource Waters (OSRWs) shall be maintained and protected, unless it can be demonstrated that lowering of water quality or a habitat modification will not have a harmful effect on the threatened or endangered species that the water supports. Kentucky Pollutant Discharge Elimination System (KPDES) permits associated with OSRWs typically contain additional requirements (e.g., biological surveys) designed to protect waters supporting listed species.

The various statutes and regulations that are in place have most likely improved water quality within the range of the Fluted Kidneyshell. However, many water standards have not been established, and other standards may be inadequate. For example, Augspurger et al. (2003, p. 2571) indicated the U.S. Environmental Protection Agency (EPA) ammonia water quality criteria (WQC) (USEPA 1985, entire) may not be protective of mussels.

State Wildlife Action Plans

The Fluted Kidneyshell was identified as a Species of Greatest Conservation Need (SGCN) in the Alabama (ADCNR 2017, p. 24), Kentucky (KDFWR 2013, entire), Tennessee (TWRA 2015, p. 304), and Virginia (VDGIF 2015, p. 26-29) State Wildlife Action Plans (SWAP). In general, these wildlife action plans identify species and habitats in need of conservation and describe opportunities for conservation. Conservation actions states have been developed include: utilizing financial incentives to protect riparian corridors and watersheds; acquisition of critical aquatic habitat; development, promotion, and implementation of best management practices; restoration of degraded habitats; better management of stormwater and agriculture and livestock waste to decrease nutrient, sediment, and pollution runoff; education of user groups on significance and importance of riparian corridors and watersheds; development and initiation of local watershed improvement projects; invasive species control; and migration barrier (dams) removal.

The Alabama SWAP specifically targeted the Fluted Kidneyshell, Cumberland Monkeyface, and Appalachian Monkeyface for reintroduction in the tailwaters of the Wilson Dam after the

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Alabama Aquatic Biodiversity Center (AABC) had carried out life history and culture techniques (ADCNR 2017, p. 238). The goal for Fluted Kidneyshell in Alabama is to establish two or more reproducing populations (ADCNR 2017, p. 244).

Conservation Programs and Efforts

The U.S. Fish and Wildlife Service (USFWS); Virginia Department of Game and Inland Fisheries (VDGIF), Aquatic Wildlife Conservation Center (AWCC); Virginia Tech, Freshwater Mollusk Conservation Center (FMCC); Kentucky Department of Fish and Wildlife Resources (KDFWR), Center for Mollusk Conservation; Tennessee Wildlife Resources Agency (TWRA) and Tennessee Valley Authority (TVA), Cumberland River Aquatic Center; and the Alabama Department of Conservation and Natural Resources (ADCNR), Alabama Aquatic Biodiversity Center have been working to restore mussel populations in the Cumberland and Tennessee River drainages since 2004. The focus has been on the propagation and translocation of common and endangered mussel species within the upper Tennessee River Basin, Duck River, Elk River, and Big South Fork Cumberland River (Hubbs 2016, entire; Phipps et al. 2018, entire; Johnson 2018, entire; M. McGregor 2019, pers. comm.). To date, propagated individuals from Clinch River stock and individuals from multiple locations within the Clinch River have been translocated and reintroduced into the Little Tennessee River, Big South Fork Cumberland River, Powell River, upper Clinch River, Nolichucky River, Duck River, and Elk River. Monitoring efforts indicate that the specimens are doing well in the Nolichucky, where it was the third most abundant species encountered during the 2016 surveys (Phipps et al. 2018, p. 14)). Recruitment is anticipated because of favorable habitat and water quality conditions (Phipps et al. 2018, p. 15). Reintroduction efforts into the Duck River have also been positive. The species was eighth in abundance in 2015 and had a density of 1.3 m2 compared to 0.3 m2 in 2010 (Hubbs 2016, p. 10). In addition, evidence of recruitment was encountered during surveys in 2013 (Hubbs 2019, p. 19). The population introduced in the Little Tennessee River (a stream with only archeological records of the species) below Calderwood Dam in 2012, has likely not persisted due to unsuitable conditions in the tailwater (Dinkins 2020, pers. comm.).

The Reservoir Release Improvement (RRI) Program, initiated by TVA in 1988, has contributed to improved mussel resources in the Duck River (Hubbs 2016, p. 17). The program focuses on improvements in dissolved oxygen concentrations below dams, including initiating minimum flows at dams in the Tennessee River drainage (Higgins and Brock 1999, p. 4). The RRI Program has improved oxygen levels, stablized water temperatures, decreased bank erosion, and stabilized habitat in several river systems (Scott et al. 1996, p. 5). Operational changes at the Tims Ford Dam on the Elk River have been implemented and appear to have improved mussel recruitment.

CURRENT CONDITION AND SPECIES VIABILITY

Methodology

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In this chapter, we assess and describe the current condition and viability of the Fluted Kidneyshell. Each population is described separately with respect to collection history, species abundance, habitat conditions, and specific stressors. Current population resiliency is then assessed for each population using habitat and population elements (described below), followed by a summary of the overall species’ redundancy and representation. We included extirpated populations in our assessment for reference and because they may have potential for future population reintroductions.

To complete our analysis, we used the best available information, including peer reviewed scientific literature, academic reports, and survey data provided by State agencies and academic institutions. An occurrence was considered current (extant) if at least one fresh dead or live specimen was reported from 2004 to 2018. Fundamental to our analysis of the Fluted Kidneyshell was the determination of analytical units (i.e., populations) at a scale useful for assessing the species. The range was divided into populations delineated by USGS 8-digit hydrological unit codes (HUC8) based on their likely isolation from each other, which is primarily, due to the presence of reservoirs and/or distance from other populations. We qualitatively assessed the current condition of each population by considering four components describing characteristics about each population’s size and distribution (population elements) and three describing each population’s physical environment (habitat elements).

Population Elements

Collection records from 2004 to 2018 were used to evaluate the current condition of four elements for each extant population: extent, abundance, continuity, and complexity. A score was assigned for each element for each population using the criteria in Table 4.1, and a total score was calculated by averaging the scores for each element (Table A.1, Appendix B). A score of “1” corresponds with “Low” condition; “2”, “Moderate”; and “3”, “High.” Extirpated populations were not assigned a score.

Extent – Population extent is the number of HUC10s currently occupied by each population (HUC8). A healthier, more resilient population would occupy several HUC10s within its population, compared to a narrower distribution within the HUC8. The number of historically occupied HUC10s is included for reference but was not factored into the score. We scored a population “High” for extent when individuals occupied three or more HUC10s, “Moderate” when individuals occupied two HUC10s, and “Low” when individuals occupied only one HUC10.

Abundance – The risk of extinction due to stochastic events is inversely proportional to population size (Haag 2012, p. 371). Therefore, it is perceived that populations that contain more individuals would be more resilient and have a greater likelihood of withstanding demographic and environmental changes. The abundance total for a population is the aggregate of all current records within a given population. Even though the entire dataset was variable, there was a greater degree of consistency in reporting abundance data or providing comments on whether a species encountered during a survey was common or rare. We scored a population “High” for abundance when we had records of >500 individuals, “Moderate” for 100-500 individuals, and “Low” for 1-99 individuals.

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Continuity – We estimated the greatest length of continuously occupied habitat within each population. It was perceived that populations would have a greater degree of genetic exchange in areas that had a greater continuous length of stream connecting the upstream and downstream extent of the population. The exchange and maintenance of genetic material are critical for the persistence of a population. There has been no comprehensive population genetic study for the Fluted Kidneyshell, so this element serves as a measure of the likelihood of gene flow. We scored a population “High” for continuity when individuals occupied greater than 100 km (62 mi.) of continuous stream, “Moderate” for 25-100 km (15.5-62 mi.), and “Low” for less than 25 km (15.5 mi.).

Complexity – Population complexity is a measure of the spatial complexity of occupied habitats. For aquatic species, complex spatial occurrence relates to a species occupying multiple streams in a watershed. If connectivity is sufficient, then more complex and dendritic (tree-like) spatial arrangements of occupied habitat will be more resilient against extinction (Fagan 2002, p. 3244). We scored a population “High” for complexity when individuals occupied the mainstem and more than two perennial tributaries, “Moderate” when individuals occupied the mainstem and two perennial tributaries, and “Low” when individuals occupied only the mainstem or the mainstem and only one perennial tributary.

Table 4.1. Scoring criteria for population elements to assess population condition.

Condition Extent Abundance Continuity Complexity > 100 km of >2 named High >2 HUC10s > 500 individuals continuous tributaries (3) occupied stream occupied occupied

25-100 km of 2 named Moderate 2 HUC10s 100-500 continuous tributaries (2) occupied individuals stream occupied occupied

<25 km of Low 1 HUC10 1 named tributary 1-99 individuals continuous (1) occupied occupied stream occupied 0 HUC10s 0 streams 0 streams Extirpated 0 individuals occupied occupied occupied

Reproduction and Recruitment – For a population to persist it must successfully reproduce and maintain viable offspring. Reproduction and recruitment were not reported for all populations, and, because mussel detectability decreases with size, the lack of evidence is not conclusive. For these reasons, we do not include this as a population element.

Habitat Elements

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The aquatic environment and all of the biological, chemical, and physical processes that occur within the lotic ecosystem are essential for the growth and maintenance of a population. These factors influence the feeding, successful reproduction, dispersal, and in-stream habitat (substrates) occupied by individuals. Alteration or degradation of water quality, water quantity, habitat quality, and habitat connectivity can often result in decreased population sizes or local extirpation, though the effects of many specific threats to the Fluted Kideneyshell are poorly understood (see Chapter 3, Factors that influence viability). Available data about habitat were used to evaluate three elements: water quality, habitat quality, and connectivity. A score was assigned for each element for each population using the criteria in Table 4.2 (Table A.2, Appendix B). A total score was calculated for each population by averaging the scores for each element. A score of “0” corresponds with “Very Low” condition; “1”, “Low”; “2”, “Moderate”; and “3”, “High.” Extirpated populations were scored because they may have potential for future population reintroductions. We acknowledge that there may be factors other than those we assessed that influence the condition of Fluted Kidneyshell populations.

Water Quality – Mussels are particularly sensitive to alterations in water quality (Haag 2012, p. 355). Stability in water quality parameters, such as temperature, pH, salinity, and ammonia are important for the resiliency of a population. Measured water quality data for all locations within the range of the Fluted Kidneyshell does not exist, but stream assessments conducted by the various water quality programs for each state, as required by sections 305b and 303d of the Clean Water Act (EPA 2017), were used as a surrogate to gauge the water quality in watersheds. We scored a population “High” for water quality when less than 40 km (25 mi.) of waterbodies within a population’s HUC8 were identified as impaired on the 305b or 303d lists, “Moderate” when 40-80 km (25-50 mi.) were identified as impaired, “Low” when 80-160 km (50-100 mi.) were identified as impaired, and “Very Low” when greater than 160 km (100 mi.) were identified as impaired.

Habitat Quality – The Fluted Kidneyshell appears to prefer substrates containing sand and gravel located in riffle and run habitats of small to large rivers. Measured and assessed habitat data for all of the populations across the range of the Fluted Kidneyshell is lacking. Land cover data (Yang et al. 2018, entire), specifically percent developed or agriculture within a watershed of the population, was used as a surrogate for an assessment of the in-stream habitat quality. It is perceived that this is acceptable because streams in watersheds that are dominated by urban or agriculture land use have an increased sediment load and are less stable than streams that have a forested stream corridor (Allan et al. 1997, p. 149, 156). We scored a population “High” for habitat quality when less than 25 percent of the watershed within a population’s HUC8 was developed or agriculture, “Moderate” when 25-50 percent was developed or agriculture, “Low” when 50-75 percent was developed or agriculture, and “Very Low” when greater than 75% was developed or agriculture.

Connectivity – The fragmentation and isolation of populations by dams and barriers is a primary threat to all aquatic species (Martin and Apse 2014, p. 7). Mussels are not only affected directly, but also indirectly by effects to host fish. As populations become isolated, they become more susceptible to local habitat and water quality degradations and stochastic demographic events. Using the National Inventory of Dams (NID) (USACE, 2019), the influence of impoundments on

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each population was qualitatively assessed. We scored a population “High” for connectivity when there were no reservoirs within the area occupied by a population, “Moderate” when impoundments were present but did not limit dispersal of current population, “Low” when impoundments potentially limited dispersal, but likely only seasonally, and “Very Low” when impoundments prohibited dispersal and fragmented populations.

Water Quantity – Although mussels can withstand stochastic low flow events during droughts, perennial streams are essential for the continued presence of mussels. Initially, drought data was examined to determine any potential effect that extreme or exceptional drought may have on the populations of Fluted Kidneyshell from 2001-2018. Data shows that no singular population experienced consecutive years of extreme or exceptional drought (NDMC 2019). Also, the effect of stream flow (water volume) on the detection probability of Fluted Kidneyshell during surveys is unknown, but is perceived to increase during periods of low flow. Therefore, it was concluded that the current available data to measure water quantity across the range of Fluted Kidneyshell does not capture the appropriate scale to be useful for the evaluation of current conditions, and will not be incorporated into the final assessment.

Table 4.2. Scoring criteria for habitat elements to assess habitat condition. Condition Water Quality Habitat Quality Connectivity < 25% High < 40 km waterbodies development/ No reservoirs (3) impaired agriculture 25-50% Impoundments present but Moderate 40-80 km waterbodies development/ do not limit dispersal of (2) impaired agriculture current population

50-75% Low 80-160 km waterbodies Dispersal potential limited, development/ (1) impaired likely only seasonally agriculture

> 75% Impoundments that Very Low > 160 km waterbodies development/ prohibits dispersal and (0) impaired agriculture fragments populations

Description of Populations

Harpeth Population

The Harpeth River is a southern tributary of the lower Cumberland River in Tennessee (Figure 4.1). The approximate 200-km length of river flows northwest before entering the Cumberland River near Ashland City, Tennessee. The entire watershed is within the Interior Plateau ecoregion and has an approximate drainage area of 2,250 km2. A few of its larger tributaries are the South Harpeth River, Little Harpeth River, West Harpeth River, Jones Creek and Turnbull Creek. The 2016 National Land Cover Data indicated that the watershed was approximately

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56% forest, 27% agriculture, 12% developed, 5% grassland, and less than 1% wetlands. The 2018 USACE NID identified 56 dams within the watershed (USACE 2019). Approximately 604 km (375 mi.) of stream segments within the watershed are considered impaired and listed on the 303d list of impaired waterbodies for low dissolved oxygen, nutrient enrichment, and E. coli (TDEC 2017, p. 39-46). The pollutant sources are pasture grazing, municipal point sources, land development, and golf courses (TDEC 2017, p. 39-46). The Harpeth Conservancy was established in 1999 to monitor and improve water quality and habitat within the watershed (Irwin 2018, p. 5). A multi-agency collaboration in 2010 worked to remove a low head dam on the mainstem, which returned the entire mainstem to free-flowing conditions.

Figure 4.1. Harpeth Fluted Kidneyshell Population HUC 10 Occupancy.

There are records from only one HUC10, South Fork Harpeth River, in the Harpeth population. The first and only reporting of the Fluted Kidneyshell was by Pilsbry and Rhoads (1896, entire). The overall recorded mussel diversity increased with survey efforts by Wilson and Clark (1914, entire), Hubbs (2002, entire), and Irwin (2018, entire); but these failed to encounter any Fluted Kidneyshells. Irwin (2018, p. 30) considered the Fluted Kidneyshell to be extirpated from the Harpeth River system.

Obey Population

The Obey River is a southern tributary of the middle Cumberland River in Kentucky and Tennessee (Figure 4.2). The approximate 150 km length of river flows north before entering the

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Cumberland River at Celina, Tennessee. The approximate drainage area is 2,452 km2 with the upper portion of the watershed within the Southwestern Appalachians ecoregion and lower portion within the Interior Plateau ecoregion. A few of its larger tributaries are the East Fork Obey River, West Fork Obey River, and Wolf River, which flows west into Dale Hollow Reservoir. The 2016 National Land Cover Data indicated that the watershed was approximately 66% forest, 19% agriculture, 6% developed, 4% grassland, and less than 1% wetlands. The 2018 USACE NID identified 16 dams within the watershed (USACE 2019). Approximately 185 km (115 mi.) of stream segments are considered impaired and have been included on Tennessee’s 303d list of impaired waterbodies for low dissolved oxygen, nutrient enrichment, metals, and flow alteration (TDEC 2016). The pollutant sources are abandoned mining, upstream impoundments, and minor municipal point sources (TDEC 2017, p. 15-17). The Service has designated a reach of the Wolf River, a reach of its tributary, Town Branch, and the West Fork Obey River as critical habitat for the Fluted Kidneyshell (USFWS 2013b, p. 59572-59573).

The Obey population consists of two HUC10s, West Fork Obey River and Wolf River. The species was first encountered in 1980, but it has not been documented from the West Fork Obey River since 1988. Moles et al. (2007, entire) encountered 11 live and 14 fresh dead specimens from five Wolf River sites. It is likely a small population that still occurs within the Wolf River.

Figure 4.2. Obey Fluted Kidneyshell Population HUC 10 Occupancy.

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Buck Creek Population

The Buck Creek population is within the approximately 4,875 km2 Cumberland River – Buck Creek HUC 8 (05130103) (Figure 4.3). Most of the northern tributaries in this HUC 8, including Fishing Creek, Pitman Creek, and Buck Creek, are within the Interior Plateau ecoregion, while the upper portion of the Cumberland River and the headwaters of the southern tributaries, including Beaver Creek and Otter Creek, are within the Southwestern Appalachian ecoregion. The 2018 USACE NID identified 16 dams within the watershed, but the Wolf Creek dam (Lake Cumberland) is a massive structure impounding an area of over 202 km2 (50,000 acres) and isolating the tributaries (USACE 2019). The 2016 National Land Cover Data indicated that the watershed was approximately 59% forest, 28% agriculture, 6% developed, 3% grassland, and less than 1% wetlands. Approximately 29 km (18 mi.) of stream segments are considered impaired and listed on the 303d list of impaired waterbodies for sedimentation and unknown causes, potentially from riparian alterations (KDEP 2018, p. 43-51). The Service has designated a reach of Buck Creek as critical habitat for the Fluted Kidneyshell (USFWS 2013b, p. 59571).

Figure 4.3. Buck Creek Fluted Kidneyshell Population HUC 10 Occupancy.

This population historically occupied four HUC10s, Beaver Creek, Buck Creek, Crocus Creek- Cumberland River, and Pitman Creek-Cumberland River. The first account of the species from the Cumberland River mainstem was by Wilson and Clark (1914, entire), but the species has not been reported from the mainstem since those records (Haag and Cicerello 2016, p. 214-215). The species has not been encountered from any of the tributaries since the 1980’s and appears

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extirpated from them, except for a small population that still remains within Buck Creek (Haag and Cicerello 2016, p. 241-215).

Big South Fork Population

The Big South Fork Cumberland River is a southern tributary of the upper Cumberland River in Kentucky and Tennessee (Figure 4.4). The watershed has an approximate 3,580 km2 drainage area. Most of the drainage area is within the Southwestern Appalachian ecoregion; it also includes small portions of the Central Appalachian ecoregion and the Interior Plateau ecoregion. The Little South Fork Cumberland River and Rock Creek are western tributaries. The confluence of the Little South Fork is inundated by Lake Cumberland, while the confluence of Rock Creek can be seasonally be inundated. The 2018 USACE NID identified 24 dams within the watershed (USACE 2019). The 2016 National Land Cover Data indicated that the watershed was approximately 79% forest, 5% agriculture, 6% developed, 9% grassland, and less than 1% wetlands. The Big South Fork National River and Recreational Area, a unit of the National Park Service, encompasses 506 km2 (125,000 acres) of the watershed and provides substantial protection. However, water quality issues from past coal mining still remain, and approximately 145 km (90 mi.) of stream segments are considered impaired and listed on the 303d list of impaired waterbodies for loss of biological integrity, pH, metals, nutrient enrichment, and E. coli (TDEC 2017, p. 12-15). The pollutant sources are abandoned mining, collection system failure, and municipal point sources (TDEC 2017, p. 12-15). The Service has designated reaches of Rock Creek, Little South Fork Cumberland River, the Big South Fork Cumberland River, and its tributaries, the New River and Clear Fork of the New River, as critical habitat for the Fluted Kidneyshell (USFWS 2013b, p. 59572).

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Figure 4.4. Big South Fork Fluted Kidneyshell Population HUC 10 Occupancy.

The Big South Fork population originally occupied three HUC10s, Sinking Creek-Big South Fork Cumberland River, Roaring Paunch-Big South Fork Cumberland River, and Little South Fork Cumberland River. The first records of the species in the watershed were from the Big South Fork mainstem in 1911 (Wilson and Clark 1914, entire). The species has also been reported from Little South Fork and Rock Creek (Haag and Cicerello 2016, p. 214-215). The Sinking Creek – Big South Fork Cumberland River HUC10 is no longer occupied, because it is inundated by Lake Cumberland. The Little South Fork once had a large population, but recent surveys only encountered three individuals (Ahlstedt et al. 2014). Recent surveys in the last five years from Rock Creek encountered 21 individuals from seven sites (Ahlstedt 2018, p. 4). In 2008, 142 individuals from the Clinch River (Tennessee River drainage), Tennessee and Virginia, were translocated from into the Big South Fork mainstem to augment the population (McGregor et al. 2008, entire).

Rockcastle Population

The Rockcastle River is a northern tributary of the upper Cumberland River in Kentucky (Figure 4.5). The watershed mostly drains the Southwestern Appalachian ecoregion, with the headwaters of the western tributaries within the Interior Plateau ecoregion. The approximate drainage area is 1,980 km2. Middle Fork Rockcastle River, South Fork Rockcastle River, Horse Lick Creek, Roundstone Creek, and Sinking Creek are a few of the larger tributaries. The 2016 National Land Cover Data indicated that the watershed was approximately 67% forest, 15% SSA Report – Fluted Kidneyshell 35 February 2021

agriculture, 8% developed, 10% grassland, and less than 1% wetlands. The watershed is mostly within the proximate boundaries of the Daniel Boone National Forest and a portion of the Rockcastle River mainstem has been designated as a Kentucky Wild and Scenic River. The confluence with the Cumberland River is inundated by Lake Cumberland. The 2018 USACE NID identified 13 dams within the watershed (USACE 2019). Approximately 60 km (37 mi.) of stream segments are considered impaired and listed on the 303d list of impaired waterbodies for loss of biological integrity, pH, metals, nutrient enrichment, sedimentation, and E. coli (KDEP 2018, p. 43-51). The pollutant sources are loss of riparian habitat, legacy coal extraction, agriculture/livestock, nonpoint sources, and urban runoff (KDOW 2018, p. 43-51).

There are records from three HUC10s, Little Rockcastle River – Rockcastle River, Middle Fork Rockcastle River, and Sinking Creek – Rockcastle River, in the Rockcastle population. The first account was from 1904 at the Livingston Ford on the Rockcastle River mainstem (Williamson 1905, p. 311). The species was encountered sporadically prior to 1990 from sites within the Rockcastle River and from sites within Horse Lick Creek. However, the species declined substantially within the next decade and the species was only encountered from Horse Lick Creek, with the last record being a single fresh dead specimen from 2003 (Haag and Warren 2004, entire; Haag and Cicerello 2016, p. 215). We consider the species extirpated from the Rockcastle watershed. The Service has designated reaches of Horse Lick Creek, the Middle Fork Rockcastle River, and the Rockcastle River as critical habitat for the Fluted Kidneyshell (USFWS 2013b, p. 59571).

Figure 4.5. Rockcastle Fluted Kidneyshell Population HUC 10 Occupancy.

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Upper Cumberland Population

The upper Cumberland River system within the HUC 8 (05130101) boundary is approximately 1,290 km2 (Figure 4.6). Laurel River is the only substantial tributary within the system. The watershed drains almost entirely within the Southwestern Appalachian ecoregion except for a small portion of the headwaters of the Laurel River. The Cumberland River is inundated by Lake Cumberland and only seasonally can the upper portions of the river, just downstream of the Cumberland Falls, experience free-flowing conditions. The 2018 USACE NID identified 20 dams within the watershed, with the Laurel River dam being the largest structure within the watershed and impacting the lower and middle portion of the Laurel River (USACE 2019). The 2016 National Land Cover Data indicated that the watershed was approximately 58% forest, 17% agriculture, 13% developed, 9% grassland, and less than 1% wetlands. Approximately 48 km (30 mi.) of stream segments are considered impaired and listed on the 303d list of impaired waterbodies for sedimentation, caused by loss of riparian habitat (KDOW 2018, p. 43-51).

Figure 4.6. Upper Cumberland Fluted Kidneyshell Population HUC 10 Occupancy. Only HUC10s partly or wholly below the falls are included.

The Upper Cumberland HUC8 spans an area above and below Cumberland Falls, which demarcates a change in the mussel fauna in the Cumberland River drainage (Haag and Cicerello 2016, p. 15). The species has never been encountered or reported above Cumberland Falls (Haag

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and Cicerello 2016, p. 214-215). There are two HUC10s within the Upper Cumberland HUC8 that occur partly or wholly below Cumberland Falls. The Fluted Kidneyshell has only been recorded from the Marsh Creek – Cumberland River HUC10, specifically the portion of this HUC10 that occurs below Cumberland Falls (the portion of the HUC10 from which Fluted Kidneyshell was recorded does not include Marsh Creek, which is upstream of Cumberland Falls). The first and only record of this population was from the Cumberland River near the base of Cumberland Falls in 1910 (Wilson and Clark 1914). Mussel surveys are scarce within this section of river, as the habitat has been greatly altered by Lake Cumberland following the construction of Wolf Creek dam. Based on the data available to us, the species is considered extirpated from the Upper Cumberland HUC8.

Buffalo Population

The Buffalo River is a southern tributary of the Duck River system. The watershed is within the Interior Plateau ecoregion and has an approximate drainage area of 1,975 km2 (Figure 4.8). The 2016 National Land Cover Data indicated that the watershed was approximately 65% forest, 19% agriculture, 4% developed, 10% grassland, and less than 1% wetlands. The 2018 USACE NID identified 42 dams within the watershed (USACE 2019). Approximately 114 km (71 mi.) of stream segments are considered impaired within the watershed and listed on the 303d list of impaired waterbodies for loss of biological integrity due to siltation, habitat alteration, flow alteration, low dissolved oxygen, and E. coli (TDEC 2017, p. 148-149). The pollutant sources are upstream impoundments, urbanization, pasture grazing, and concentrated animal feeding operation (TDEC 2017, p. 148-149). The Service has designated a reach of the Buffalo River as critical habitat for the Fluted Kidneyshell (USFWS 2013b, p. 59577).

There are records from only one HUC10, Upper Buffalo River, in the Buffalo population. The only record of the species is from Ortmann (1924, entire). Several other surveys, Isom and Yokley (1968, entire), Van der Schalie (1973, entire), Ahlstedt (1991, entire), Reed (2014, entire), and Reed et al. (2019, p. 356) have failed to encounter the species, and it is considered extirpated (Ahlstedt et al. 2017, p. 69).

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Figure 4.7. Buffalo Fluted Kidneyshell Population HUC 10 Occupancy.

Upper Duck Population

The Duck River is an eastern tributary of the Tennessee River drainage. The upper watershed is within the Interior Plateau ecoregion and has an approximate drainage area of 3,060 km2 (Figure 4.7). An approximate 346 km (215 mi.) reach has been designated as critical habitat for the Fluted Kidneyshell. The 2016 National Land Cover Data indicated that the watershed was approximately 38% forest, 47% agriculture, 9% developed, 5% grassland, and 1% wetlands. The 2018 USACE NID identified 13 dams within the watershed (USACE 2019). The Normandy dam is the largest and impounds the headwaters. Approximately 655 km (407 mi.) of stream segments are considered impaired within the watershed and listed on the 303d list of impaired waterbodies for loss of biological integrity, pH, metals, nutrient enrichment, low dissolved oxygen, sedimentation, flow alteration, and E. coli (TDEC 2017, p. 139-148). The pollutant sources are municipal point sources, pasture grazing, dairies, impoundments, and landfill (TDEC 2017, p. 139-148). The Service has designated a reach of the Duck River as critical habitat for the Fluted Kidneyshell (USFWS 2013b, p. 59577).

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Figure 4.8. Upper Duck Fluted Kidneyshell Population HUC 10 Occupancy.

The upper Duck population occupies two HUC10s, Flat Creek-Duck River and Upper Duck River. Ortmann (1924, entire) first reported the species from the Duck River. Isom and Yokley (1968, entire) surveyed the sites of Ortmann (1924) in 1965, but indicated that the Fluted Kidneyshell was not encountered. However, a museum record (OSUM 16235) from 1965 exists (Ahlstedt et al. 2017, p. 69). The species was considered extirpated from the Duck System (Ahlstedt et al. 2017, p. 30), and recent surveys by Irwin (2018) did not yield any specimens. The Tennessee Wildlife Resources Agency (TWRA) is currently leading efforts to re-establish a viable Fluted Kidneyshell population within the Duck River. In 2004, specimens were translocated from the Clinch River to the Duck River. Over subsequent years (2005-2016), approximately 7,000 specimens have been translocated from the Clinch River to multiple sites within the Duck River. In 2013, evidence of recruitment was encountered from a muskrat midden (Hubbs 2019, p. 19).

Pickwick Lake Population

The Tennessee River system within the HUC8 (06003005) has an approximate area of 5,910 km2 (Figure 4.9). The majority of the watershed is within the Interior Plateau ecoregion; the western portion is within the Southeastern Plains ecoregion; and the southern headwaters of Town Creek and Big Nance Creek are in the Southwestern Appalachian ecoregion. The 2018 USACE NID identified 42 dams within the watershed (USACE 2019). The presence of Pickwick Landing

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Dam and Wilson Dam on the Tennessee River isolates all of the tributaries. The 2016 National Land Cover Data indicated that the watershed was approximately 40% forest, 32% agriculture, 8% developed, 12% grassland, and 3.5% wetlands. Approximately 158 km (98 mi.) of stream segments are considered impaired and listed on the 303d list of impaired waterbodies for nutrients, metals, pathogens (E. coli) siltation, and habitat alteration (ADEM 2016, p. 9-12; TDEC 2017, p. 136). The pollutant sources are agriculture, pasture grazing, channelization, and urban runoff.

There are records from one HUC10, Tennessee River – Pickwick Lake, in the Pickwick Lake population. Ortmann (1925, entire) reported several records of the species near Muscle Shoals from the Tennessee River and from Spring Creek and Cypress Creek near their confluence with the Tennessee River (Williams et al. 2008). All records are pre-impoundment of the Tennessee River and the species has not been reported since Ortmann’s surveys. The species is considered extirpated from this section of the Tennessee River.

Figure 4.9. Pickwick Lake Fluted Kidneyshell Population HUC 10 Occupancy.

Lower Elk Population

The Elk River is a northern tributary of the Tennessee River. The lower Elk is entirely within the Interior plateau ecoregion and has an approximate drainage area of 2,495 km2 (Figure 4.10). The 2016 National Land Cover Data indicated that the watershed was approximately 45% forest, 42% agriculture, 6% developed, 6% grassland, and 1% wetlands. The 2018 USACE NID

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identified 9 dams within the watershed (USACE 2019). The lower 53 km (33 mi.) of the river is inundated by Wheeler Lake. Approximately 230 km (143 mi.) of stream segments are considered impaired within the watershed and listed on the 303d list of impaired waterbodies for loss of biological integrity due to siltation, habitat alteration, nutrient enrichment, and pathogens (E. coli) (ADEM 2016, p. 9-12; TDEC 2017, p. 130-136). The pollutant sources identified include urbanization, silviculture, pasture grazing, concentrated animal feeding operation, municipal point source, and off-road vehicles (TDEC 2017, p. 130-136). An approximate 160- km (100-mi.) section of the Elk River from the impoundment of Wheeler Lake upstream to the confluence of Farris Creek has been designated as critical habitat for the Fluted Kidneyshell. The Service has designated a reach of the Elk River in this HUC8 as critical habitat for the Fluted Kidneyshell (USFWS 2013b, p. 59577).

The Lower Elk population occupies only one HUC10, Anderson Creek – Elk River. No historical records are known from this section of river, but the species is known from the Elk River further upstream, near Winchester, Tennessee. In 2016, TWRA released 141 Fluted Kidneyshells from the Clinch River into the Elk River at a site near Winding Stair Bluff (Hubbs 2019, p. 41). Monitoring of the reintroductions is ongoing.

Figure 4.10. Lower Elk Fluted Kidneyshell Population HUC 10 Occupancy.

Upper Elk Population

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The Elk River is a northern tributary of the Tennessee River. The upper Elk is mostly within the Interior plateau ecoregion, with the headwaters of the southeastern tributaries draining from the Southwestern Appalachian ecoregion. The drainage area is approximately 3,322 km2 (Figure 4.11). The 2016 National Land Cover Data indicated that the watershed was approximately 43% forest, 42% agriculture, 7% developed, 5% grassland, and1% wetlands. The 2018 USACE NID identified 22 dams within the watershed, with Tims Ford dam being the largest and most significant impoundment within the watershed (USACE 2019). Approximately 692 km (430 mi.) of stream segments are considered impaired within the watershed and listed on the 303d list of impaired waterbodies for loss of biological integrity due to siltation, habitat alteration, nutrient enrichment, and E. coli (TDEC 2017, p. 130-136). The pollutant sources are upstream impoundments, urbanization, pasture grazing, concentrated animal feeding operation, municipal point source, and specialty crop production (TDEC 2017, p. 130-136). The Service has designated a reach of the Elk River in this HUC 8, below Tims Form Dam, as critical habitat for the Fluted Kidneyshell (USFWS 2013b, p. 59577).

The Upper Elk population occupies two HUC10s, Norris Creek-Elk River and Boiling Fork Creek. Two records exist within the watershed from the 1960’s, prior to the completion of the Tims Ford dam. The reservoir separates the records, and the species has not been encountered post-impoundment. The species is considered extirpated within this section of the Elk River.

Figure 4.11. Upper Elk Fluted Kidneyshell Population HUC 10 Occupancy.

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Wheeler Population

The Tennessee River system within the HUC8 (06003002) has an approximate area of 7,490 km2 (Figure 4.12). The majority of the watershed is within the Interior Plateau ecoregion, with the southern and eastern portions within the Southwest Appalachian ecoregion. The 2018 USACE NID identified 37 dams within the watershed (USACE 2019). Wheeler Dam is the largest and most significant dam in the watershed and isolates nearly all of the tributaries. The 2016 National Land Cover Data indicated that the watershed was approximately 35% forest, 39% agriculture, 12% developed, 7% grassland, and 4% wetlands. Approximately 367 km (228 mi.) of stream segments are considered impaired and listed on the 303d list of impaired waterbodies for loss of biological integrity due to siltation, nutrients, low dissolved oxygen, flow alteration, and habitat alteration (ADEM 2016, p. 9-12; TDEC 2017, p. 129-130). The pollutant sources are agriculture, non-irrigated crop production, pasture grazing, land development, channelization, and urban runoff.

The Wheeler population occupies two HUC10s, Piney Creek and Lower Flint River. Only three records exist within the watershed (Ortmann 1925, entire; Williams et al. 2008, p. 629) and were prior to the construction of Wheeler Dam in 1936. Isom and Yokley (1973, entire) conducted mussel surveys within the watershed between 1965-1967 in the Flint River and Paint Rock River, but did not encounter any Fluted Kidneyshell specimens and noted a 42% decline in the mussel fauna. The species is considered extirpated from the watershed.

Figure 4.12. Wheeler Lake Fluted Kidneyshell Population HUC 10 Occupancy.

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Guntersville Population

The Tennessee River system within the HUC8 (06003001) has an approximate area of 5,170 km2 and is entirely within the Southwest Appalachian ecoregion (Figure 4.13). The 2018 USACE NID identified 47 dams within the watershed (USACE 2019). Gunthersville Dam is the largest and most significant dam within the watershed and isolates nearly all of the tributaries. The 2016 National Land Cover Data indicated that the watershed was approximately 50% forest, 30% agriculture, 7% developed, 7% grassland, and 1% wetlands. Approximately 153 km (95 mi.) of stream segments are considered impaired and listed on the 303d list of impaired waterbodies for loss of biological integrity due to siltation, nutrients, turbidity, flow alteration, and E. coli (ADEM 2016, p. 9-12; TDEC 2017, p. 128-129). The pollutant sources are agriculture, mining, non-irrigated crop production, pasture grazing, land development, and urban runoff.

The Guntersville population occupies only one HUC10, Widows Creek – Tennessee River. A single record exists for this watershed: Tennessee River near Bridgeport, Alabama (Ortmann 1925, entire; Williams et al. 2008, p. 629) prior to the construction of Gunthersville Dam (1939). The species is considered extirpated from the watershed.

Figure 4.13. Gunthersville Lake Fluted Kidneyshell Population HUC 10 Occupancy.

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Lower French Broad Population

The French Broad River is a southern tributary of the Tennessee River (Figure 4.14). The southern half of the French Broad River drains a portion of the Great Smoky Mountains within the Blue Ridge Mountain ecoregion and flows into the Ridge and Valley ecoregion. The drainage area is approximately 2,065 km2. The 2018 USACE NID identified 21 dams within the watershed (USACE 2019). Douglas Dam is the largest and most significant dam within the watershed and isolates the eastern tributaries of the watershed. The 2016 National Land Cover Data indicated that the watershed was approximately 62% forest, 19% agriculture, 10% developed, 3% grassland, and less than 1% wetlands. Approximately 338 km (210 mi.) of stream segments are considered impaired within the watershed and listed on the 303d list of impaired waterbodies for loss of biological integrity due to siltation, habitat alteration, nutrient enrichment, temperature (within trout streams) and E. coli (TDEC 2017, p. 69-72). The pollutant sources are upstream land development, pasture grazing, septic tanks, municipal point sources, and collection system failure (TDEC 2017, p. 59-72). The Service has designated a reach of the French Broad River as critical habitat for the Fluted Kidneyshell (USFWS 2013b, p. 59575).

The Lower French Broad population occupies only one HUC10, French Broad River. The only record obtained from recent searches of databases and museums was shell material from the French Broad River, McCrosky Island site (MCM 9565). Parmalee and Bogan (1998, p. 204- 205) depict accounts of the species near the confluence of French Broad River and Little Pigeon River, but those records were not obtained during record searches. The species is part of the historical lower French Broad fauna but is currently considered extirpated.

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Figure 4.14. Lower French Broad Fluted Kidneyshell Population HUC 10 Occupancy.

Nolichucky Population

The Nolichucky River is an eastern tributary of the French Broad River (Figure 4.15). The upper portion of the watershed is within the Blue Ridge Mountain ecoregion and the lower portion is within the Ridge and Valley ecoregion. The river originates in North Carolina and flows westward into Tennessee and has a drainage area of approximately 4,570 km2. The 2018 USACE NID identified 27 dams within the watershed (USACE 2019). The most substantial dam in the watershed is the Nolichucky Dam which created Davy Crockett Lake (1913). The dam is still present but ceased generating power in 1972 because of the large sediment load into it; the area has been converted into a wildlife management area (Hubbs 2019, p. 50). The 2016 National Land Cover Data indicated that the watershed was approximately 58% forest, 32% agriculture, 7% developed, 2% grassland, and less than 1% wetlands. Approximately 1,191 km (740 mi.) of stream segments are considered impaired in the watershed and listed on the 303d list of impaired waterbodies for loss of biological integrity due to siltation, habitat alteration, nutrient enrichment, low dissolved oxygen, and E. coli (TDEC 2017, p. 72-82). The pollutant sources are upstream land development, pasture grazing, unrestricted cattle access, municipal point sources, and sand and gravel mining (TDEC 2017, p. 72-82). The Service has designated a reach of the Nolichucky River as critical habitat for the Fluted Kidneyshell (USFWS 2013b, p. 59575).

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Figure 4.15. Nolichucky Fluted Kidneyshell Population HUC 10 Occupancy.

The Nolichucky population occupies two HUC10s, Little Chucky Creek – Nolichucky River and Cove Creek – Nolichucky River. Parmalee and Bogan (1998, p. 204-205) indicate that the Fluted Kidneyshell occurred within the Nolichucky River, but did not depict any records of the species on the distribution map along the river. It is unclear when the first record of the species was reported, and no records prior to 2000 were encountered during museum and database searches. Reintroduction efforts by TWRA have translocated approximately 6,300 specimens from sites within the Clinch River to two sites within the Nolichucky River since 2004, but recruitment has not yet been documented (Hubbs 2019, p. 50-54).

Holston Population

The Holston River is an eastern tributary of the upper Tennessee River in Tennessee (Figure 4.16). The entire watershed is within the Ridge and Valley ecoregion and has a drainage area of approximately 2,595 km2. The 2018 USACE NID identified 18 dams within the watershed (USACE 2019). Cherokee Dam is the largest and most significant dam in the watershed and is situated in the middle of the watershed, which would prevent any dispersal potential between upstream and downstream portions. The 2016 National Land Cover Data indicated that the watershed was approximately 46% forest, 28% agriculture, 13% developed, 8% grassland, and less than 1% wetlands. Approximately 668 km (415 mi.) of stream segments are considered impaired in the watershed and listed on the 303d list of impaired waterbodies for loss of biological integrity due to siltation, habitat alteration, nutrient enrichment, low dissolved oxygen, SSA Report – Fluted Kidneyshell 48 February 2021

and E. coli (TDEC 2017, p. 62-68). The pollutant sources are upstream impoundment, pasture grazing, unrestricted cattle access, septic tanks, animal feeding operations, municipal point sources, and collection system failure (TDEC 2017, p. 62-68). The Service has designated a reach of the Holston River as critical habitat for the Fluted Kidneyshell (USFWS 2013b, p. 59575).

The Holston population occupies only one HUC10, Cherokee Lake – Holston River. Two records were discovered during museum and database searches, ranging from 1927-1980. The species is considered extirpated from the mainstem Holston River (Parmalee and Bogan 1998, p. 204-205).

Figure 4.16. Holston Fluted Kidneyshell Population HUC 10 Occupancy.

North Fork Holston Population

The North Fork Holston River is an eastern tributary of the Holston River in Tennessee and Virginia (Figure 4.17). The entire watershed is within the Ridge and Valley ecoregion and has a drainage area of approximately 1,890 km2. The 2018 USACE NID identified two dams within the watershed, which are small, placed in the tributaries, and do not limit the dispersal potential of most fishes and mussels (USACE 2019). The 2016 National Land Cover Data indicated that the watershed was approximately 69% forest, 23% agriculture, 4% developed, 4% grassland, and less than 1% wetlands. Approximately 40 km (25 mi.) of stream segments are considered impaired in the watershed and listed on the 303d list of impaired waterbodies for loss of SSA Report – Fluted Kidneyshell 49 February 2021

biological integrity (benthic macroinvertebrate assessment), chlorides, E. coli, and mercury (fish tissue) (TDEC 2017, p. 51; VDEQ 2018, p. 959-1050). The pollutant sources are livestock, residential runoff, and highway and bridge runoff (not construction related) (TDEC 2017, p. 51; VDEQ 2018, 959-1050). The Service has designated reaches of the North Fork Holston River and Big Moccasin Creek as critical habitat for the Fluted Kidneyshell (USFWS 2013b, p. 59573- 59573).

The North Fork Holston population occupies four HUC10s, Abrams Creek – North Fork Holston River, Big Moccasin Creek – North Fork Holston, Tumbling Creek – North Fork Holston River, and Laurel Creek – North Fork Holston River. The North Fork Holston is the type locality for the Fluted Kidneyshell (Say 1825, entire) and has been one of the most reliable streams to encounter the species. Nearly 2,000 specimens have been observed since 2004 from roughly twenty collections (VA heritage data).

Figure 4.17. North Fork Holston Fluted Kidneyshell Population HUC 10 Occupancy.

South Fork Holston Population

The South Fork Holston River is an eastern tributary of the Holston River in Tennessee and Virginia, with a drainage area of approximately 3,070 km2 (Figure 4.18). The watershed is mostly within the Ridge and Valley ecoregion, with the southern headwaters within the Blue Ridge ecoregion. The 2018 USACE NID identified 17 dams within the watershed, with Boone

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and South Holston Dams isolating most of the tributaries within the watershed (USACE 2019). The 2016 National Land Cover Data indicated that the watershed was approximately 53% forest, 31% agriculture, 13% developed, 1% grassland, and less than 1% wetlands. Approximately 653 km (406 mi.) of stream segments are considered impaired in the watershed and listed on the 303d list of impaired waterbodies for loss of biological integrity due to siltation, nutrient enrichment, habitat alteration, E. coli, flow alteration, and temperature alteration (TDEC 2017, p. 51-58; VDEQ 2018, p. 959-1050). The pollutant sources are pasture grazing, upstream impoundment, animal feeding operations, municipal point source, channelization, and septic tanks (TDEC 2017, p. 51-58; VDEQ 2018, p. 959-1050). The Service has designated a reach of the Middle Fork Holston River as critical habitat for the Fluted Kidneyshell (USFWS 2013b, p. 59574).

The South Fork Holston population occupies only one HUC10, Middle Fork Holston River. Records indicate that the species was often encountered during 1970-2000 (unpublished VA heritage data), but appears to be rare currently. Shell material has been collected in the last twelve years from four sites, but only seven live specimens have been encountered from two sites (Henley et al. 2013; unpublished VA heritage data).

Figure 4.18. South Fork Holston Fluted Kidneyshell Population HUC 10 Occupancy.

Clinch Population

The Clinch River flows westward from Virginia into Tennessee until its confluence with the Tennessee River near Kingston, Tennessee (Figure 4.19). Its drainage area is approximately SSA Report – Fluted Kidneyshell 51 February 2021

5,105 km2. The watershed is primarily within the Ridge and Valley ecoregion with the headwaters of a few northern tributaries within the Central Appalachian ecoregion. The 2018 USACE NID identified 27 dams within the watershed (USACE 2019). Norris Dam is the most significant dam, impounds the lower portion of the Clinch River, and prohibits any dispersal with other populations (i.e., Powell). However, most of the other dams are smaller and present within tributaries of the Clinch River, which allows an extensive length free-flowing river in the mainstem. The 2016 National Land Cover Data indicated that the watershed was approximately 63% forest, 18% agriculture, 8% developed, 8% grassland, and less than 1% wetlands. Approximately 571 km (355 mi.) of stream segments are considered impaired in the watershed and listed on the 303d list of impaired waterbodies for loss of biological integrity due to siltation and nutrients, habitat alterations, nutrient enrichment, low pH, and E. coli, (TDEC 2017, p. 94- 95; VDEQ 2018, 959-1050). The pollutant sources are pasture grazing, mines, permitted and abandoned, urbanization, and municipal point sources (TDEC 2017, p. 94-95; VDEQ 2018, p. 959-1050). The Service has designated reaches of the Clinch River and its tributaries, the Little River and Copper Creek, as critical habitat for the Fluted Kidneyshell (USFWS 2013b, p. 59574).

Figure 4.19. Clinch Fluted Kidneyshell Population HUC 10 Occupancy.

The Clinch population occupies eight HUC10s, Big Cedar Creek – Clinch River, Copper Creek, Dumps Creek – Clinch River, Indian Creek – Clinch River, Little River, North Fork Clinch River – Clinch River, Stony Creek – Clinch River, and Swords Creek – Clinch River. The Clinch River represents the most extensive population of Fluted Kidneyshell. Over half of the records obtained were from the Clinch River system, with numerous accounts indicating hundreds of SSA Report – Fluted Kidneyshell 52 February 2021

specimens encountered. In 2016, it was estimated that approximately 48,500 individuals occurred in the Clinch River at Kyle’s Ford, representing approximately 13% of the mussel community surveyed (Richard 2020, pers. comm.). Multiple sites within the Clinch River have been used as the source stock for several population augmentations and reintroductions across the historical range of the species. Clinch River stock has been either propagated or reintroduced into the Big South Fork of the Cumberland River and into the Duck River, Elk River, Little Tennessee River, and Nolichucky River of the Tennessee River drainage (Haag and Cicerello 2016, p. 214-215; Hubbs 2019, entire). The Duck River has achieved natural recruitment from these efforts, and a specimen was discovered from a muskrat midden in 2013 (Hubbs 2019, p. 19). Although the Clinch River contains the largest population of Fluted Kidneyshell, the river has experienced mussel die-offs in recent years, as discussed in section 3.6. The Fluted Kidneyshell has been affected from the die-offs; causes of the die-offs and their effects of the population are currently being investigated (Richard 2020, pers. comm).

Powell Population

The Powell River is a northern tributary of the Clinch River that flows westward from Virginia into Tennessee (Figure 4.20). The watershed is mostly within the Ridge and Valley ecoregion with the eastern headwaters within the Central Appalachians ecoregion. The drainage area is approximately 2,455 km2. The 2018 USACE NID identified 12 dams within the watershed (USACE 2019). Most of the dams are small and near the eastern headwaters. However, the lower segment of the Powell River is impounded by Norris Dam. The impoundment isolates the Powell River from other populations and the possibility of recruitment from outside sources. The 2016 National Land Cover Data indicated that the watershed was approximately 58% forest, 11% agriculture, 8% developed, 19% grassland, and less than 1% wetlands. Approximately 314 km (195 mi.) of stream segments are considered impaired in the watershed and listed on the 303d list of impaired waterbodies for loss of biological integrity due to siltation, habitat alterations, nutrient enrichment, loss of native mussels, and E. coli, (TDEC 2017, p. 96-97; VDEQ 2018, p. 959-1050). The pollutant sources are pasture grazing, animal feeding operations, urbanization, and municipal point sources (TDEC 2017, p. 96-97; VDEQ 2018, p. 959-1050). The Service has designated a reach of the Powell River as critical habitat for the Fluted Kidneyshell (USFWS 2013b, p. 59574).

The Powell population occupies four HUC10s, South Fork Powell-Powell River, North Fork Powell River-Powell River, Powell River, and Wallen Creek-Powell River. The species was first reported by Ortmann (1918). Ortmann encountered the species near the headwaters of the Powell River, near Big Stone Gap, Virginia, within the Central Appalachians ecoregion. This account represents the only confirmed record for the species within that ecoregion. The mussel fauna has declined within the Powell River over the last 100 years, but the species still persists, although less frequently than from past collections. The most recent intensive survey of mussels within the Powell was from Johnson et al. (2012, entire), and they reported 35 live Fluted Kidneyshells from five sites.

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Figure 4.20. Powell Fluted Kidneyshell Population HUC 10 Occupancy.

Species Viability

The objective of an SSA is to assess the viability of a focal species by characterizing the status of the species in terms of its redundancy and representation across its entire range and the resiliency of each of its populations (Figure 4.21). The purpose is to assess the species over time and define its ability or likelihood to sustain wild populations (viability). This is done by providing historical context and presenting the current condition and future scenarios (Status Quo, Pessimistic, and Optimistic) for the viability of the species, in association with its needs.

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Figure 4.21. The application of resiliency, representation, and redundancy at the species and population levels.

Resiliency

Population resiliency is one of the cornerstones of the SSA framework; multiple Fluted Kidneyshell populations must be able to withstand natural or anthropogenic stochastic disturbances, such as hydrological fluctuations or water quality and habitat degradations, to maintain species viability. For a population to be more likely to persist following such events, each population should exhibit an ability to reproduce and maintain a sufficient size, as well as occupy stream reaches that allow for genetic exchange and contain enough suitable habitat with adequate water quality.

To assess the current resiliency of each extant Fluted Kidneyshell population, the metrics of the population elements and the habitat elements were averaged (Table 4.3). Only five populations were classified as having a moderate resiliency; none were classified as having high resiliency (Table 4.3, Figure 4.22).

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Table 4.3. Fluted Kidneyshell current population resiliency conditions (2019). Extant populations with their resiliency conditions indicated in bold. Assessed Assessed Current Population Habitat Population Drainage Populations Elements Elements Resiliency Cumberland Harpeth Extirpated Low Extirpated Obey Low Low Low Buck Creek Low Moderate Low Big South Fork Moderate Low Moderate Rockcastle Extirpated Moderate Extirpated Upper Cumberland Extirpated Low Extirpated Tennessee Buffalo Extirpated Moderate Extirpated Upper Duck Moderate* Low Low Pickwick Lake Extirpated Low Extirpated Lower Elk Low* Low Low Upper Elk Extirpated Low Extirpated Wheeler Lake Extirpated Low Extirpated Guntersville Lake Extirpated Low Extirpated Lower French Broad Extirpated Low Extirpated Nolichucky Moderate* Moderate Moderate Holston Extirpated Low Extirpated North Fork Holston Moderate Moderate Moderate South Fork Holston Low Low Low Clinch High Low Moderate Powell Moderate Moderate Moderate * Reintroduced populations from Clinch River stock.

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Figure 4.22. Current population resiliency of Fluted Kidneyshell (2019).

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Representation

Representation refers to the ability of a species to adapt to changing environmental conditions over time and is characterized by the degree of genetic and environmental diversity within and among the populations. The more genetically diverse and more diversity of environments a species occupies, the greater the species’ capacity to adapt to changes in its environment. No range-wide genetic information is available for the Fluted Kidneyshell, but the distribution does allow for an evaluation of the species across drainages and among ecoregions, in which local adaptions may have occurred. Therefore, we describe species representation in terms of river drainage variability and ecoregion variability, which each can be considered proxies for genetic diversity.

River Drainage Variability – The Fluted Kidneyshell is currently extant in three populations in the Cumberland drainage and seven in the Tennessee drainage. We further evaluated the number of currently occupied HUC10s to capture the current representation of the species relative to its historical representation. The number of HUC10s occupied by the species has declined 51% overall, and declined 71% in the Cumberland drainages and 42% in the Tennessee drainage from its historical occurrence (Table 4.4). It is important to note that some of the individuals in the Big South Fork population, in the Cumberland drainage, were introduced from Clinch River stock within the Tennessee drainage.

Table 4.4. River drainage variability. # of historically # of currently Drainage occupied HUC10s occupied HUC10s % Decline Cumberland: 14 4* 71 Tennessee: 31 18 42 Range wide: 45 22 51 * Two of these HUC10s comprise the Big South Fork population, into which individuals of Clinch River genetic stock has been introduced.

Ecoregion Variability – The Cumberland and Tennessee River drainages cover eight different Level 3 Ecoregions (Figure 4.23). The HUC8 distribution of Fluted Kidneyshell includes six of the ecoregions; Southeastern Plains (65), Blue Ridge (66), Ridge and Valley (67), Southwestern Appalachians (68), Central Appalachians (69), and Interior Plateau (71). However, the distribution of collections where Fluted Kidneyshells have been encountered only occurs within four of these ecoregions: Ridge and Valley, Southwestern Appalachians, Central Appalachians, and Interior Plateau. The number of currently occupied HUC10s for each of these ecoregions was compared to the historical distribution to assess the condition of each ecoregion and how well the species may be represented. The species is still extant within each of the historical ecoregions occupied except for the Central Appalachians, where it has not been reported in over 100 years. Although still extant in the Southwestern Appalachian and Interior Plateau ecoregions, a substantial decline has occurred in these two ecoregions. The Southwestern Appalachian ecoregion has lost 71% of its historically occupied HUC10s. Four of the 14 historically occupied HUC10s in the Interior Plateau ecoregion are extant; however, it is important to note that three of these four populations consist of individuals introduced from the Clinch River stock within the Ridge and Valley ecoregion. Thus, the only extant native Interior SSA Report – Fluted Kidneyshell 58 February 2021

Plateau population is the Buck Creek population in the Cumberland drainage. No native populations remain in the Interior Plateau ecoregion in the Tennessee drainage. Because no genetic studies have been conducted for this species, we do not know the actual corresponding loss of genetic diversity. Only the Ridge and Valley ecoregion showed a relatively minor loss of occupied HUC10s, with an estimated loss of 25%. However, several of the HUC10s are isolated and genetic exchange is prohibited because of the presence of reservoirs and/or and distances to other occupied HUCs.

Overall, the species has maintained representation in the two river drainages where it historically occurred (Cumberland and Tennessee Rivers) and has maintained representation within three of the four historical ecoregions. However, the species has been extirpated from over half of its range, and representation occurs from mostly isolated populations with minimal or no possibility of genetic exchange due to the presence of reservoirs and distance to other populations. Additionally, the only native extant population in the Interior Plateau ecoregion has low resiliency. It is important to note that the representation of the Interior Plateau ecoregion within the Tennessee drainage is actually from individuals from the Ridge and Valley ecoregion. Much of the historical genetic diversity from the Interior Plateau ecoregion of the Tennessee River drainage has likely been lost, unless new localities are discovered. The Southwest Appalachian ecoregion is only represented by two populations, one with moderate resiliency and one with low resiliency. One of these populations, Big South Fork, has been augmented with individuals from Clinch River genetic stock. Introducing genetics from a different ecoregion (Ridge and Valley) and a different HUC8 drainage (Tennessee River) compromises the genetic integrity of the Big South Fork population. Based on all these factors, we consider the species to have low representation.

Table 4.5. Level 3 Ecoregion variability.

Ecoregion # of historically # of currently % Level 3 Ecoregion Code occupied HUC10s occupied HUC10s Decline Ridge and Valley 67 20 15 25 Southwestern Appalachians 68 10 3* 71 Central Appalachians 69 1 0 100 Interior Plateau 71 14 1^ 93 * Two of these HUC10s comprise the Big South Fork population, into which individuals of Clinch River genetic stock has been introduced. ^ The Interior Plateau contains three additional populations of individuals reintroduced from the Clinch River (Ridge and Valley ecoregion).

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Figure 4.23. Fluted Kidneyshell populations relative to level III ecoregions. SSA Report – Fluted Kidneyshell 60 February 2021

Redundancy

Redundancy refers to the ability of a species to withstand catastrophic events (a rare destructive natural event or episode involving many populations). A species is more likely to persist following devastating events if it has multiple resilient populations distributed across a large geographic area. High redundancy “guards against irreplaceable loss of representation” (Redford et al. 2011 p. 42; Tear et al. 2005 p. 841) and minimizes the effect of localized extirpation on the range-wide persistence of a species (Shaffer and Stein 2000, p. 308). For a species to exhibit greater redundancy, the populations should not be completely isolated, and immigration and emigration between populations should be achievable.

Redundancy for the Fluted Kidneyshell is characterized by having multiple, resilient and representative populations distributed across the species’ range. Currently, the species is represented by ten isolated populations with low or moderate resiliency that are vulnerable to extirpations from catastrophic events, such as extreme droughts or chemical spills. Connectivity between extant populations has also been reduced, or likely eliminated, by impoundments and other physical habitat conditions. This lack of connectivity between populations increases the effect and likelihood of localized stochastic events that could be detrimental to these populations and lead to extirpations. Based on all these factors, we consider the species to have low to moderate redundancy.

Current Condition Summary

Currently, 10 of the 20 historical Fluted Kidneyshell populations are extant, with four and six populations occupying the Cumberland and Tennessee River drainages, respectively (Figure 4.22). Several of the extirpated populations are the result of impoundments (i.e., Holston), while the causes of extirpation for other populations are associated with other, undefined threats or combination of threats. Though we did not attempt to quantify declines in numbers and distribution of individuals within extant populations, a qualitative review of the records indicates that there is an overall negative range-wide population trend. None of the extant populations exhibit high resiliency, five are considered to have moderate resiliency, and five exhibit low resiliency. The reintroduction efforts into the Duck, Elk, and Nolichucky Rivers from Clinch River stock have kept the species extant in those systems, with some evidence of natural recruitment in the Duck River. The Clinch population is the largest population with over 10,000 individuals recorded during surveys of multiple tributaries, covering over 100 km of stream length within the last 15 years. Representation was evaluated by assessing river drainage and ecoregion occurrence and was determined to be low. The species continues to occupy both the Cumberland and Tennessee River drainages. However, the species appears to be extirpated from the Central Appalachians ecoregion, extirpated from the Interior Plateau ecoregion within the Tennessee River drainage, and only persisting in the Southwestern Appalachians ecoregion in two populations. Redundancy, based on the number of extant populations and their resiliencies, is considered low to moderate.

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FUTURE CONDITIONS

The previous chapters have identified and defined the biological and environmental factors essential for viability and characterized the current condition of the Fluted Kidneyshell using the resiliency, representation, and redundancy concept. Based on this information, and using the 3R’s, an evaluation of plausible future scenarios was conducted to forecast the future viability of the Fluted Kidneyshell.

Future Scenario Considerations

Previously identified factors influencing the viability of the Fluted Kidneyshell were degradation of habitat and water quality and the isolation of habitats and populations (connectivity), which is affected by various land use practices (i.e., urbanization, agriculture), barriers, invasive species, and climate. Projecting these factors into the future presents a challenge and can vary among populations across the range of the species. In addition, a synergistic effect is likely to occur with changing environmental conditions. For example, increased impervious surfaces accompanying urbanization coupled with increased precipitation trends will produce more extreme flow fluctuations that will likely result in increased stream channel destabilization. Increased sedimentation from the eroding stream channels, in turn, changes water quality parameters, such as temperature and dissolved oxygen, and physical habitat in streams. To assist with the development of the future scenarios, urbanization models, climate projections, and other pertinent information for the region were used in conjunction with the assessment framework used in Chapter 4 (Current Conditions) to estimate future population resiliency.

The SLUETH (Slope, Land use, Excluded area, Urban area, Transportation, Hillside area) model was used to account for development across the landscape (Terando et al. 2014). The model simulates patterns of urban development that are consistent with past urban growth and transportation network patterns, including the sprawling, fragmented, “leapfrog” development that has been dominant in the southeastern United States (Terando et al. 2014, p. 2). Considering a “business-as-usual” (BAU) scenario of urban growth, which expects future development to match current development rates, Terando et al. (2014) projected the extent of urbanized areas to increase across the southeastern United States for the next 50 years by approximately 100 - 192 percent. This BAU rate was used to forecast the future land development across the Cumberland and Tennessee River drainages (Figure 5.1). It is expected that with increased urbanization, forest cover decreases, and water quality and habitat quality will be degraded through increased inputs of point source and non-point source pollutants (e.g., siltation, organic enrichment).

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2020

SLEUTH Projected Urban Growth

Urban <2.5 5 10 20 30 40 50 60 70 80 2040 90 95 97.5 >97.5

Protected Areas October 2012

Federal Land Native American Land

State Land Local Land Private Conservation Joint Ownership/Unknown

Cumberland and Tennessee Drainages 2070

Figure 5.1. Projected urban growth (SLUETH), 2020, 2040, 2070, within the Cumberland and Tennessee River drainages.

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In general, increases in extreme heat, storm intensity, droughts, heavy precipitation events (e.g., flood), and rising sea levels and storm surges are to be expected to be experienced in the Southeastern United States, but will vary based on the projected climate conditions (NCILT 2012, p. 27). To address the possible changes in climate, the Fifth Assessment Report (AR5) by the Intergovernmental Panel on Climate Change (IPCC) was used (IPCC 2014). The AR5 provides different greenhouse gas emission scenarios, known as Representative Concentration Pathways (RCPs), to make climate projections. The models account for population growth, energy generation, technology, land use, and social-economical changes over time and provides a plausible pathway for obtaining a projected outcome. We used the extreme scenarios, RCP8.5 and RCP2.6, to represent the projected future climate condition Scenario 2 (Pessimistic) and Scenario 3 (Optimistic), respectively, for the Fluted Kidneyshell. The RCP2.6 projects that an aggressive climate policy is implemented, and greenhouse gas emissions would be reduced and lower than current levels, resulting in minimal climate change effects experienced. The RCP8.5 projects no climate policy and no checks on emissions, resulting in intensified effects of climate change.

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Uncertainty

Through the course of this analysis, it was necessary to make certain assumptions. These assumptions introduce uncertainty to our assessment of current condition and our projections of future conditions. The following are uncertainties recognized in this report:

• We assumed that the species’ historical range is represented by known collection records. The actual historical range prior to European colonization is unknown and may have included other tributaries of the Cumberland and Tennessee Rivers. • To determine the species’ current range, we used all records obtained between 2004 and 2018 and evaluated how those records compared to historical collections. Not all historical streams or sites within a specific tributary system were visited over the last 12 years, but we made the decision to include some of these streams as part of the species’ current range. Streams were included if available information indicated that habitat or water quality conditions had not changed significantly within these systems since the species’ historical collection, and recent collection records were available from the receiving stream or other throughout the system (in some cases habitat and/or water quality conditions had improved). Alternatively, if available information suggested that habitat and water quality conditions were poor and no recent collections were available, these streams were not included as part of the species’ current range. • We assumed that levels of public ownership within extant populations will not change over time. • Future conservation efforts are dependent on funding availability, available conservation opportunities, and the willing cooperation of our partners, so only a portion of actions may be undertaken in the future. • We used an available urbanization (development) model (SLEUTH) to predict how future urbanization could impact habitats used by the Fluted Kidneyshell. This model uses spatial observations of past urban growth and transportation networks to make predictions about future urbanization rates. We acknowledge that this model does not account for other potential sources of habitat disturbance or water quality impairment (e.g. agriculture, surface coal mining) that could impact the species in the future.

Future Scenarios

5.3.1 Scenario 1 (Status Quo)

Under this scenario, factors influencing current Fluted Kidneyshell populations are projected to remain on current trajectories.

Factors influencing Fluted Kidneyshell populations are projected to remain on current trajectories into the future for the next 50 years. Degradations of water quality and habitat are expected to remain proportional and consistent across the range of the species. Climate patterns, impoundments, and hydrological conditions remain similar and land use patterns continue at a constant and predictable rate (Lawler et al. 2014), including urban development and agriculture

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practices (Terando et al. 2014; Lasier et al. 2016). Therefore, it was anticipated that the length of impaired stream, the proportion of development and agricultural landcover, and the presence and impact of impoundments would be relatively similar to the conditions currently observed. In addition, existing regulatory mechanisms remain and are implemented consistently and conservation actions, such as land protection, population augmentation, public outreach, and monitoring continue at a similar rate. Under this scenario, we assessed the trajectory of the Fluted Kidneyshell populations to continue on the current trajectory for the next 50 years.

Resiliency

We project the overall resiliency of the Fluted Kidneyshell to decline under Scenario 1 (Table A.3, Appendix B).

Cumberland River Drainage Historically, six populations occurred within the Cumberland drainage, but only three populations remain today. If conditions continue on the current trajectory, we project that only one of these populations will persist 50 years from now (Table 5.1). Each of these populations is isolated from each other by Lake Cumberland. Records for the Obey population have declined since it was first encountered, and the current population is small and only occupies a short reach (approximately 5 km) of one stream. The Buck Creek population has also declined and currently occupies an approximate 20-km (12 mi.) reach of one stream. The habitat elements in the Obey population are currently assessed as low. We project that the water quality in the Buck Creek population will decline due to increased development in the areas in and around Somerset, Kentucky. We project that the Buck Creek and Obey populations will continue to decline and become extirpated in the next 50 years. It is expected that the Big South Fork Cumberland population will persist. The population currently occupies three streams; however, long-term effects of past oil and coal mining continue to threaten the population. The mussel fauna in Little South Fork has especially experienced significant declines (Ahlstedt et al. 2014). We project that this trend will continue and that Fluted Kidneyshell will be extirpated from Little South Fork in 50 years. The remaining individuals in the Big South Fork population will be low in abundance and occur only in Rock Creek and the mainstem of the Big South Fork Cumberland River. These localities will be isolated seasonally when the backwaters of the Lake Cumberland inundate the Big South Fork upstream and slightly beyond the confluence of Rock Creek during high water.

Tennessee River Drainage Currently, half of the 14 historic populations within the Tennessee River drainage have been extirpated. Under this scenario, we project the resiliency for three of the seven current populations to be moderate, two populations to be low, and two to be extirpated. Three of these populations, Upper Duck, Lower Elk, and Nolichucky, are currently extant because of reintroduction efforts, beginning in 2004, 2016, and 2004, respectively. Monitoring is ongoing at these sites, but more time is needed to assess the long-term success of these reintroductions. The population in the Upper Duck is the only one indicating recruitment to date. Ultimately, the success and establishment of self-sustaining populations will depend in part on the water quality and habitat quality at the reintroduction sites. We project that one of these reintroduced populations will not persist for the next 50 years. It is difficult to predict which one, but for the

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purposes of this document we chose the Lower Elk population, because it was most recently reintroduced and has habitat elements assessed as low. Of the reintroduced populations that do persist, we only expect a portion of the reintroduced individuals to survive long-term. Individuals have currently been reintroduced within a small reach (<5 km) of stream in the Nolichucky that flows through two HUC10s. We project that the Nolichucky population will persist in only one of these two HUC10s. For the Upper Duck population, we project that the reintroduced population will persist, but the number of individuals will decline. We project that the seasonal mussel die-offs in the Clinch River mainstem will continue and expand within the watershed. The number of individuals will decline, and the species will become rarer throughout the currently occupied reaches. Because the population is currently so robust, the projected population element score will remain high. The resulting population will experience declines in reproduction, due to the low density of individuals, and will continue on a downward projection. We project that the South Fork Holston will become extirpated, because of the current rarity of the species there and its low assessed habitat elements. Each of the populations remaining in the Tennessee drainage in this scenario, except for the Clinch River, have a linear distribution that will make them susceptible to catastrophic events. Additional future extirpations are a real possibility, though it is difficult to predict when these would occur.

Table 5.1. Projected Fluted Kidneyshell resiliency under Scenario 1 (Status Quo). Declines from current condition are indicated in red and bold font. Projected Projected Projected Population Habitat Resiliency Drainage Populations Elements Elements Condition Cumberland Harpeth Extirpated Low Extirpated Obey Extirpated Low Extirpated Buck Creek Extirpated Low Extirpated Big South Fork Low Low Low Rockcastle Extirpated Moderate Extirpated Upper Cumberland Extirpated Low Extirpated Tennessee Buffalo Extirpated Moderate Extirpated Upper Duck Moderate Low Low Pickwick Lake Extirpated Low Extirpated Lower Elk Extirpated Low Extirpated Upper Elk Extirpated Low Extirpated Wheeler Lake Extirpated Low Extirpated Guntersville Lake Extirpated Low Extirpated Lower French Broad Extirpated Low Extirpated Nolichucky Low Moderate Low Holston Extirpated Low Extirpated North Fork Holston Moderate Moderate Moderate South Fork Holston Extirpated Low Extirpated Clinch High Low Moderate Powell Moderate Moderate Moderate

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Representation

Under Scenario 1 (Status Quo), the Fluted Kidneyshell is expected to continue to have low representation among river drainages and ecoregions. Populations will persist in the Cumberland and Tennessee River drainages; however, the Big South Fork population will be the only population remaining in the entire Cumberland River drainage and in the Southwest Appalachians ecoregion (Figure 5.2). The resulting low resiliency and redundancy leaves the species vulnerable to future extirpation in the Cumberland River drainage and the Southwest Appalachians ecoregion. Representation of the populations within the Tennessee River drainage will mostly be limited to the upper portion of the drainage in 50 years. The Powell, Clinch and North Fork Holston populations within the Ridge and Valley ecoregion are expected to have multiple HUC10s occupied, and the populations are considered to have moderate resiliency. The only other remaining population in the upper Tennessee River drainage and Ridge and Valley ecoregion is the Nolichucky population, which is expected to be small and of low resiliency. The species is expected to be extirpated from the South Fork Holston River in 50 years. In addition, the species is extirpated from the Central Appalachians ecoregion and is expected to remain absent from that ecoregion into the future. The Duck population will represent the only population in the lower portion of the drainage and the Interior Plateau ecoregion within the Tennessee River drainage. However, the Duck population is genetically similar to the Clinch population, because the stock of reintroduced individuals came from the Clinch River. Therefore, there is no historical genetic representation within the Interior Plateau ecoregion of the Tennessee River drainage.

Redundancy

Under Scenario 1 (Status Quo), the Fluted Kidneyshell is expected to lose four more populations, with none of the remaining populations considered to have high resiliency. Thus, redundancy will decrease to low.

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Figure 5.2. Fluted Kidneyshell representation, Scenario 1 (Status Quo).

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5.3.2 Scenario 2 (Pessimistic)

Under this scenario, factors influencing current Fluted Kidneyshell populations are projected to deteriorate to a level which increases risk and likelihood of local extirpation of populations in the future.

Under Scenario 2 (Pessimistic), the risk and likelihood of extirpation increases because of increased activities within the watersheds that degrade water quality and habitat conditions for the Fluted Kidneyshell. It is expected that the length of impaired waterbodies will increase with increased urban development and agriculture practices. In addition, climate change will have a more detrimental effect on the species. Severe drought and flooding events will become more frequent, resulting in warmer stream temperatures and increased channel erosion, deposition, and scour. Regulatory mechanisms will become less protective of aquatic ecosystems, and conservation efforts have failed or are no longer carried out because of budget constraints.

Resiliency

Compared to Scenario 1 (Status Quo), we project the overall resiliency of the Fluted Kidneyshell to decline even more under Scenario 2 (Table A.4, Appendix B).

Cumberland River Drainage The expected resiliency of the three current populations of Fluted Kidneyshell in the Cumberland River drainage is expected to decrease within the next 50 years (Table 5.2). The Obey and Buck Creek populations will become extirpated due to the current low number of individuals and continued water quality degradation. We project that the Little South Fork tributary in the Big South Fork population will become extirpated, but individuals in the mainstem will persist because of some protection afforded by the Big South Fork National River and Recreational Area. However, the loss of one occupied tributary reduces the population’s complexity and reduces its overall resiliency from moderate to low. We project that the Big South Fork population will persist 50 years from now, but its status beyond 2070 will be tenuous without successful efforts to improve the quality of the water and habitat.

Tennessee River Drainage We project that only three of the seven remaining populations within the Tennessee River drainage will persist 50 years from now under Scenario 2. Three of the current populations, Upper Duck, Lower Elk, and Nolichucky, are extant because of recent reintroduction efforts. The earliest of these introductions occurred in 2004 and, while some initial success has been observed, more time is needed to determine if these efforts will be successful long-term. The long-term success of these reintroductions will depend in part on the water quality and habitat quality at a reintroduction site being supportive of Fluted Kidneyshell populations. However, the specific aspects of water quality and habitat and their effects on Fluted Kidneyshell remain poorly understood. Under this scenario, we project that none of the reintroduced populations persist for 50 years. Additionally, we project that the South Fork Holston population will become extirpated, because the species is currently present there in very low numbers and the habitat is assessed as low. We project that the North Fork Holston population will decline as a result of water quality degradation in the watershed. Likewise, the population in the Powell

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River will decline as it continues to be affected by the ongoing degradation to water and habitat quality. We project that these populations will continue to persist, but their resiliencies will decrease from moderate to low. We project that the seasonal mussel die-offs in the Clinch River mainstem will continue and expand within the watershed, effecting the entire population. Without conservation efforts to research the cause of the die-offs and implement intervention, the population will decline precipitously towards extirpation. Each of the populations remaining in the Tennessee drainage in this scenario, except for the Clinch River, have a linear distribution that will make them susceptible to catastrophic events. Additional future extirpations are a real possibility, though it is difficult to predict when these would occur. Continued water quality degradation and habitat degradation from development limit opportunities for future reintroductions throughout the species’ historical range.

Table 5.2. Projected Fluted Kidneyshell resiliency under Scenario 2 (Pessimistic). Declines from current condition are indicated in red and bold font. Projected Projected Projected Population Habitat Resiliency Drainage Populations Factors Elements Condition Cumberland Harpeth Extirpated Low Extirpated Obey Extirpated Low Extirpated Buck Creek Extirpated Low Extirpated Big South Fork Moderate Low Low Rockcastle Extirpated Low Extirpated Upper Cumberland, below Falls Extirpated Low Extirpated Tennessee Buffalo Extirpated Moderate Extirpated Upper Duck Extirpated Low Extirpated Pickwick Lake Extirpated Low Extirpated Lower Elk Extirpated Low Extirpated Upper Elk Extirpated Low Extirpated Wheeler Lake Extirpated Low Extirpated Guntersville Lake Extirpated Low Extirpated Lower French Broad Extirpated Low Extirpated Nolichucky Extirpated Moderate Extirpated Holston Extirpated Low Extirpated North Fork Holston Low Moderate Low South Fork Holston Extirpated Low Extirpated Clinch Low Low Low Powell Low Moderate Low

Representation

Under Scenario 2 (Pessimistic), the Fluted Kidneyshell representation is expected to decrease 50 years from now. The species will persist within both the Cumberland and Tennessee River drainages, but only a small population within one HUC10 will remain in the Cumberland River

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drainage (Big South Fork) and only three populations in the Tennessee River drainage (Figure 5.3). All of the populations in the Tennessee River drainage will have low resiliency and continue to be isolated from each other because of impoundments. It is expected that the species will be extirpated from the Interior Plateau ecoregion, and only one population (Big South Fork) will occur within the Southwestern Appalachian ecoregion. The Ridge and Valley ecoregion will have three small, isolated populations remaining. The resulting representation will be low.

Redundancy

Under Scenario 2 (Pessimistic), the Fluted Kidneyshell is expected to lose redundancy, with the extirpation of six populations within the next 50 years. Only four populations are expected to be extant, with each having low resiliency. Each of the populations is isolated from each other because of impoundments and susceptible to catastrophic events and spills because each is relatively small and mostly linear. The redundancy will decrease to low.

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Figure 5.3. Fluted Kidneyshell representation, Scenario 2 (Pessimistic).

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5.3.3 Scenario 3 (Optimistic)

Under this scenario, factors influencing current Fluted Kidneyshell populations are projected to improve and promote recruitment and enhancement of populations into the future.

Under Scenario 3 (Optimistic), factors influencing Fluted Kidneyshell populations and habitat conditions are projected to improve, and fewer streams will be considered impaired. Changes in climate conditions are considered to be less severe, with lower annual increases in temperature and less severe drought and flooding events. Urbanization rates are expected to be lower than predicted by the SLUETH models. Lastly, regulatory mechanisms become more favorable for conservation of the species, and conservation actions (e.g., land protection, population reintroduction and augmentation, monitoring) increase. The response of Fluted Kidneyshell populations is positive; current populations increase in abundance and extent, and new populations become reestablished within the historical range.

Resiliency

We project the overall resiliency of the Fluted Kidneyshell to improve under Scenario 3 (Table A.5, Appendix B).

Cumberland River Drainage Under Scenario 3, we do not project additional extirpations within the Cumberland River drainage (Table 5.3). Improved water quality and habitat conditions within the Big South Fork Cumberland, Obey, and Rockcastle Rivers are favorable and enhance conservation efforts, but are limited and restricted in Buck Creek only to areas within the Daniel Boone National Forest. Conservation efforts re-establish a viable Fluted Kidneyshell population in the Rockcastle River system and augment populations in the Big South Fork Cumberland and Obey River systems. The resiliencies of these populations are projected to be moderate, while Buck Creek is expected to maintain low resiliency.

Tennessee River Drainage We project that conservation efforts to reintroduce and bolster the populations within the Upper Duck, Lower Elk, and Nolichucky Rivers are successful and that conservation efforts improve water quality in these populations. The extent of the species is expanded within those systems and resiliencies increase to moderate. We also project conservation efforts to improve water and habitat quality in the Powell, North Fork Holston, and South Fork Holston Rivers benefit those populations. The Powell and North Fork Holston populations maintain moderate resiliencies, the North Fork Holston population increases to high, and the South Fork Holston population increases to moderate. We project that additional research identifies the cause of the mussel die- offs in the Clinch River, and effective intervention is implemented to prevent further declines. In addition, ongoing and future conservation efforts in the Clinch River improve the water and habitat quality for the population. The Clinch population increases in resiliency to high and continues to represent the largest and most complex population, occupying multiple tributaries within the watershed.

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Table 5.3. Projected Fluted Kidneyshell resiliency under Scenario 3 (Optimistic). Improvements from current condition are indicated in green and bold font. Projected Projected Projected Population Habitat Resiliency Drainage Populations Elements Elements Condition Cumberland Harpeth Extirpated Low Extirpated Obey Moderate Moderate Moderate Buck Creek Low Moderate Low Big South Fork Moderate Moderate Moderate Rockcastle Low Moderate Low Upper Cumberland Extirpated Low Extirpated Tennessee Buffalo Extirpated Moderate Extirpated Upper Duck Moderate Low Moderate Pickwick Lake Extirpated Low Extirpated Lower Elk Moderate Moderate Moderate Upper Elk Extirpated Low Extirpated Wheeler Lake Extirpated Low Extirpated Guntersville Lake Extirpated Low Extirpated Lower French Broad Extirpated Low Extirpated Nolichucky Moderate Moderate Moderate Holston Extirpated Low Extirpated North Fork Holston Moderate High Moderate South Fork Holston Moderate Moderate Moderate Clinch High Moderate High Powell Moderate Moderate Moderate

Representation

Under Scenario 3 (Optimistic), the species will persist within both the Cumberland and Tennessee River drainages. Although the Cumberland River drainage is expected to increase by one population with the reintroduction of the Fluted Kidneyshell into the Rockcastle River, the genetic representation will remain the same for the Cumberland drainage, because the reintroduced stock would come from another population. The number of populations in the Tennessee River drainage will remain as it is currently, but all of those populations are expected to have a resiliency of either moderate or high. Ecoregion variability is expected to remain the same as it is currently. Representation would increase to low-moderate, due to the increased resiliency of the populations.

Redundancy

Under Scenario 3 (Optimistic), the successful reintroduction of an additional population (i.e., Rockcastle River) will slightly increase the Fluted Kidneyshell redundancy compared to the current condition. In addition, population augmentation will increase the number of HUC10s occupied by several populations compared to the current conditions. The increased resiliency of

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nearly all of the populations, because of improved environmental conditions, will enhance the species’ redundancy. The redundancy is expected to increase to moderate under the optimistic scenario.

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Figure 5.4. Fluted Kidneyshell representation, Scenario 3 (Optimistic).

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Future Viability

The future scenario assessment was developed to describe the viability of the Fluted Kidneyshell over time in the terms of resilience, representation, and redundancy. To account for the uncertainty associated with future projections, three plausible scenarios (Status Quo, Pessimistic, and Optimistic) with different trajectories (see Table 5.4) were used to capture the potential variation of changes likely to be observed in the Cumberland and Tennessee River drainages, and the potential impact those changes might have on Fluted Kidneyshell populations (Table 5.5). Each scenario considered elements of change in urbanization, climate, and conservation activity, and how these predicted changes would impact Fluted Kidneyshell water quality and habitat.

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Table 5.4. Summary of future scenario descriptions. Future Condition Category Description Scenario Climate Future Development Species Condition Water Quality Habitat Quality Current level of Current Climate Current level of species regulation and Current level of effects continue on Urbanization response to impacts on oversight, including regulation, barrier 1 trend into the future, continues on landscape; current limited protective WQ improvement/removal (Status Quo) resulting in increased trend with levels of propagation & standards requirements projects, and riparian heat, drought, storms current levels augmentation and/or and utilization of basic buffer protections and flooding translocation capacity technologies for effluent treatment Degraded instream and Species response to Moderate to Worse riparian habitat synergistic impacts on Climate Future Declining water quality conditions from landscape result in (RCP8.5) Urbanization resulting from increased impacts, significant declines 2 exacerbated effects rates at high end increased impacts, limited regulation, coupled with limited (Pessimistic) of climate change of BAU model limited regulation and fewer barrier propagation capacity experienced related (~200%) restrictions, and overall improvement/removal and/or limited ability to to heat, drought, reduced protections projects, and overall augment/reintroduce storms and flooding reduced riparian buffer propagules protections Existing resources Moderate to targeted to highest Improved Climate Urbanization Optimistic species Slightly increased priority barrier Future (trending rates realized at response to impacts; impacts tempered by removals; riparian 3 towards RCP 2.6) lower levels targeted propagation utilizing improved buffer protections (Optimistic) resulting in minimal than BAU and/or restoration technologies and remain intact; targeted effects of heat, model predicts efforts utilizing existing implementing riparian connectivity drought, storms and (<100%) resources and capacity protection strategies projects; regulatory flooding mechanisms remain the same

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Table 5.5. Resiliency condition summary of Fluted Kidneyshell populations. Projected Future Scenarios Drainage Populations Current 1 2 3 Condition Status Quo Pessimistic Optimistic Cumberland Harpeth Extirpated Extirpated Extirpated Extirpated Obey Low Extirpated Extirpated Moderate Buck Creek Low Extirpated Extirpated Low Big South Fork Moderate Low Low Moderate Rockcastle Extirpated Extirpated Extirpated Low Upper Cumberland Extirpated Extirpated Extirpated Extirpated Tennessee Buffalo Extirpated Extirpated Extirpated Extirpated Upper Duck Low Low Extirpated Moderate Pickwick Lake Extirpated Extirpated Extirpated Extirpated Lower Elk Low Extirpated Extirpated Moderate Upper Elk Extirpated Extirpated Extirpated Extirpated Wheeler Lake Extirpated Extirpated Extirpated Extirpated Guntersville Lake Extirpated Extirpated Extirpated Extirpated Lower French Broad Extirpated Extirpated Extirpated Extirpated Nolichucky Moderate Low Extirpated Moderate Holston Extirpated Extirpated Extirpated Extirpated North Fork Holston Moderate Moderate Low Moderate South Fork Holston Low Extirpated Extirpated Moderate Clinch Moderate Moderate Low High Powell Moderate Moderate Low Moderate Total extant 10 6 4 11 populations:

Overall Summary

This species status assessment (SSA) report describes a comprehensive review of the available data and analytical process used to assess the viability of the endangered Fluted Kidneyshell. During this process, the resiliency, representation, and redundancy were evaluated using pertinent information associated with the biological and environmental requisites and any threats that imperil the species to determine current condition and the future viability of the species for the next 50 years.

Overall, in the future the species will continue to be exposed to numerous threats that increases its risk of extirpation. Land development and altered weather patterns from climate change will degrade habitat and water quality. Fragmentation among the populations as well as within a population will continue to prevent or minimize genetic exchange. However, conservation efforts, such as reintroductions and population augmentation, and environmental improvements can mitigate or decreased threats to abate extirpation and maintain species persistence.

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Under all of our future scenarios, the species is expected to persist into 2070, albeit with a loss of viability under Scenarios 1 (Status Quo) and 2 (Pessimistic). We project that the viability will improve some under Scenario 3 (Optimistic), which is contingent on the success of conservation activities to improve habitat conditions and population reintroduction and augmentations.

This concludes our assessment of Fluted Kidneyshell needs, current condition, and future condition. This SSA will follow the species through its ESA life cycle, recovery planning, consultations, and all policy-related decision-making until recovery and eventual delisting. To better assess the status of the species in the future, regular monitoring and research of the species is needed. This SSA should be updated as new information becomes available.

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LITERATURE CITED

Ahlstedt, S.A. 1991. Cumberlandian mollusk conservation program. Activity 1: Mussel surveys in six Tennessee Valley streams. Walkerana 5:123–160.

Ahlstedt, S.A. 2018. Current status of freshwater mussels (Bivalvia: Unionidae) in Rock Creek, McCreary County, Kentucky. Final Report: Kentucky State Nature Preserves Commission and University of Tennessee Institute of Agriculture. 14 pp.

Ahlstedt, S.A., and J.D. Tuberville. 1997. Quantitative reassessment of the freshwater mussel fauna in the Clinch and Powell Rivers, Tennessee and Virginia. Pp. 74 in: K.S. Cummings, A.C. Buchanan, C.A. Mayer, and T.J. Naimo, eds. Conservation and management of freshwater mussels II: initiatives for the future. Proceedings of a UMRCC symposium, October 1995, St. Louis, Missouri. Upper Mississippi River Conservation Committee, Rock Island, Illinois.

Ahlstedt, S., R. Butler, Z. Couch, S. Bruenderman, M. Compton, and E. Brett. 2014. Current status of freshwater mussel populations in the Little South Fork Cumberland River drainage, McCreary and Wayne counties, Kentucky (2013): Continuing collapse of a once fabulous fauna. Final report: U.S. Fish and Wildlife Service, Frankfort, KY; and Kentucky Waterways Alliance, Louisville, KY. 17 pp.

Ahlstedt, S.A., J.R. Powell, R.S. Butler, M.T. Fagg, D.W. Hubbs, S.F. Novak, S.R. Palmer, and Paul. D. Johnson. 2017. Historical and current examination of freshwater mussels (Bivalvia: Margaritiferidae: Unionidae) in the Duck River basin Tennessee, U.S.A. Malacological Review 45:1-163.

Alabama Department of Conservation and Natural Resources (ADCNR). 2017. Alabama wildlife action plan 2015-2020. Alabama Department of Conservation and Natural Resources, Division of Wildlife and Freshwater Fisheries. 503 pp.

Alabama Department of Environmental Management. 2016. Alabama’s Final 2016 303(d) list. Available at http://www.adem.state.al.us/programs/water/wquality/2016AL303dList.pdf

Allan, J.D., D.L. Erickson, and J. Fay. 1997. The influence of catchment land use on stream integrity across multiple scales. Freshwater Biology 37:149-161.

Archambault, J.M, C.M. Bergeron, W.G. Cope. 2017. Assessing toxicity of contaminants in riverine suspended sediments to freshwater mussels. Environmental Toxicology and Chemistry 36:395-407.

Augspurger, T., A.E. Keller, M.C. Black, W.G. Cope, and F.J. Dwyer. 2003. Water quality guidance for protection of freshwater mussels (Unionidae) from ammonia exposure. Environmental Toxicology and Chemistry 22:2569–2575.

SSA Report – Fluted Kidneyshell 82 February 2021

Barling, R.D., and I.D. Moore. 1994. Role of buffer strips in management of waterway pollution: A review. Environmental Management 18:543–558.

Bartsch, M.R., T.J. Newton, J.W. Allran, J.A. O’Donnell, and W.B. Richardson. 2003. Effects of pore-water ammonia on situ survival and growth of juvenile mussels (Lampsilis cardium) in the St. Croix riverway, Wisconsin, USA. Environmental Toxicology and Chemistry 22:2561–2568.

Barnhart, M. C. 2008. Unio Gallery: http://unionid.missouristate.edu. (Accessed March 9, 2020).

Barnhart, M.C., W.R. Haag, and W.N. Roston. 2008. Adaptations to host infection and larval parasitism in Unionoida. Journal of the North American Benthological Society 27:370– 394.

Berkman, H.E., and C.F. Rabeni. 1987. Effect of siltation on stream fish communities. Environmental Biology of Fishes 18:285-294.

Booth, D.B. and C.J. Jackson, 1997. Urbanization of aquatic systems – degradation thresholds, stormwater detention, and the limits of mitigation. Water Resources Bulletin 33:1077– 1090.

Brabec, E., S. Schulte, and P.L. Richards. 2002. Impervious surfaces and water quality: a review of current literature and its implications for watershed planning. Journal of Planning Literature 16:499-514.

Brim Box, J. and J. Mossa. 1999. Sediment, land use, and freshwater mussels: Prospects and problems. Journal of the North American Benthological Society 18:99–117.

Bringolf, R.B., R.M.Heltsley, T.J. Newton, C.B. Eads, S.J. Fraley, D. Shea, and W.G. Cope. 2010. Environmental occurrence and reproductive effects of the pharmaceutical fluoxetine in native freshwater mussels. Environmental Toxicity and Chemistry 29:1311- 1318.

Brooker, M.P. 1985. The ecological effects of channelization. The Geographic Journal 151:63–69.

Brown, A.V., M.M. Lyttle, and K.B. Brown. 1998. Impacts of gravel mining on gravel bed streams. Transactions of the American Fisheries Society 127:979–994.

Carpenter, S.R., N.F. Caraco, D.L. Correll, R.W. Howarth, A.N. Sharpley, and V.H. Smith. 1998. Nonpoint pollution of surface waters with phosphorus and nitrogen. Ecological Applications 8:559-568.

Chapin, F.S., III, P.A. Matson, H. Mooney. 2002. Principles of terrestrial ecosystem ecology. Springer-Verlag, New York, New York, USA. 529 pp.

SSA Report – Fluted Kidneyshell 83 February 2021

Cherry, D.S., Scheller, J.L., Cooper, N.L., Bidwell, J.R. 2005. Potential effects of Asian clam (Corbicula fluminea) die-offs on native freshwater mussels (Unionidae) I: water-column ammonia levels and ammonia toxicity. Journal of the North American Benthological Society 24:369-380.

Chetty A.N. and K. Indira. 1994 Alterations in the tissue lipid profiles of Lamellidens marginalis under ambient ammonia stress. Bulletin of Environmental Contamination and Toxicology 53:693-698.

Colle, D.E., J.V. Shireman, W.T. Haller, J.C. Joyce, and D.E. Canfield. 1987. Influence of Hydrilla on harvestable sport-fish populations, angler use, and angler expenditures at Orange Lake, Florida. North American Journal of Fisheries Management 7:410–417.

Cooper, C.M. 1993. Biological effects of agriculturally derived surface water pollutants on aquatic systems. Journal of Environmental Quality 22:402–408.

Davis, V.M. and J.B. Layzer. 2012. Life history of the Fluted Kidneyshell Ptychobranchus subtentum. The American Midland Naturalist 167:79-95.

DeGregorio, A. 1914. Su taluni molluschi di acqua dolce di America [American fresh water shells of America]. II Naturalista Siciliano 22(2-3): 31-72, plates 3-12.

Deshayes, D.P. 1835. Histoire naturelle des Animaux san vertebrates de Lamarck. 2nd ed. Vol.6: iv + 600 pp.

Dinkins, G. 2020. Email about Clinch River mussel die-off, February 21, 2020.

Eissa, A.E. and M.M. Zaki. 2011. The impact of global climatic changes on the aquatic environment. Procedia Environmental Sciences Volume 4:251–259.

Fagan, W.F. 2002. Connectivity, fragmentation, and extinction risk in dendritic metapopulations. Ecology 83:3243-3249.

Fent, K., A.A. Weston, and D. Caminada. 2006. Ecotoxicology of human pharmaceuticals. Aquatic Toxicology 76:122-159.

Ferreira-Rodríguez, N., R. Sousa, and I. Pardo. 2018. Negative effects of Corbicula fluminea over native freshwater mussels. Hydrobiologia 810:85-95.

Flynn, K. and T. Spellman. 2009. Environmental levels of atrazine decrease spatial aggregation in the freshwater mussel, Elliptio complanata. Ecotoxicology and Environmental Safety 72:1228-1233.

SSA Report – Fluted Kidneyshell 84 February 2021

Frazier B.E., T.H. Naimo, M.B. and Sandheinrich. 1996. Temporal and vertical distribution of total ammonia nitrogen and un-ionized ammonia nitrogen in sediment pore water from the upper Mississippi River. Environmental Toxicology Chemistry 15:92-99.

Frierson, L.S. 1927. A Classified and Annotated Checklist of the North American Naiades. Baylor University Press: Waco, Texas. 111 pp.

Fuller, S.L.H. 1974. Clams and mussels (Mollusca: Bivalvia). Pp. 215–273 in: C.W. Hart, Jr., and S.L.H. Fuller, eds. Pollution ecology of freshwater invertebrates. Academic Press, New York.

Gagne, F., D.J. Marcogliese, C. Blaise, and A.D. Gendron. 2001. Occurrence of compounds estrogenic to freshwater mussels in surface waters in an urban area. Environmental Toxicology 16:260-268.

Gagne, F., B. Bouchard, C. Andre, E. Farcy, and M. Fournier. 2011. Evidence of feminization in wild Ellipitio complanata mussels in the receiving waters downstream of a municipal effluent outfall. Comparative Biochemistry and Physiology Part C Toxicology and Pharmacology 153:99-106.

Galbraith, H.S., D.E. Spooner, and C.C. Vaughn. 2010. Synergistic effects of regional climate patterns and local water management on freshwater mussel communities. Biological Conservation 143:1175-1183.

Gatenby, C.M., R.J. Neves, and B.C. Parker. 1996. Influence of sediment and algal food on cultured juvenile freshwater mussels. Journal of the North American Benthological Society 15:597-609.

Gibson, K.J., J.M. Miller, P.D. Johnson, and P.M. Stewart. 2018. Acute toxicity of chloride, potassium, nickel, and zinc to federally threatened and petitioned mollusk species. Southeastern Naturalist 17:239-256.

Giddings, E.M.P., A.H. Bell, K.M. Beaulieu, T.F. Cuffney, J.F. Coles, L.R. Brown, F.A. Fitzpatrick, J. Falcone, L.A. Sprague, W.L. Bryant, M.C. Peppler, C. Stephens, and G. McMahon. 2009. Selected physical, chemical, and biological data used to study urbanizing streams in nine metropolitan areas of the United States, 1999-2004: U.S. Geological Survey Data Series 423, 11 pp. + data tables.

Goudreau, S.E., R.J. Neves, and R.J. Sheehan. 1993. Effects of wastewater treatment plant effluents on freshwater mollusks in the upper Clinch River, Virginia, U.S.A. Hydrobiologia 252:211-230.

Guenther, C.B. and A. Spacie. 2006. Changes in fish assemblages structure upstream of impoundments within the upper Wabash River basin, Indiana. Transactions of the American Fisheries Society 135:570-583.

SSA Report – Fluted Kidneyshell 85 February 2021

Haag, W.R., and M.L. Warren, Jr. 2004. Species richness and total population size of freshwater mussels in Horse Lick Creek, Kentucky in 2003. Final report. USDA Forest Service, Oxford, MS. 43 pp.

Haag, W. 2009. Past and future patterns of freshwater mussel extinctions in North America 10 during the Holocene. Holocene Extinctions (2009):107–128.

Haag, W. 2012. North American Freshwater Mussels: Natural History, Ecology, and Conservation. Cambridge University Press, Cambridge, New York. 538 pp.

Haag, W. 2019. Personal Communication, October 2019.

Haag, W.R. 2019. Reassessing enigmatic mussel declines in the United States. Freshwater Mollusk Biology and Conservation 22:43-60.

Haag, W. 2020. Personal Communication, March 2020.

Haag, W.R., and R.R. Cicerello. 2016. A distributional atlas of the freshwater mussels of Kentucky. Scientific and Technical Series Number 8. Kentucky State Nature Preserves Commission, Frankfort, Kentucky. 299 pp.

Hagman, T.E. 2000. Stress analysis and Mussel (Bivalvia: Unionidae) bed mapping of Buck Creek in Pulaski County, Kentucky, utilizing Geographic Information Systems with special emphasis on the four endangered mussels living in the stream. Eastern Kentucky University. Unpublished Master’s Thesis. 100 pp.

Hartfield, P.D. 1993. Headcuts and their effect on freshwater mussels. Pp. 131–141 in: K.S. Cummings, A.C. Buchanan, and L.M. Koch, eds. Conservation and management of freshwater mussels. Proceedings of a UMRCC symposium, October 1992, St. Louis, Missouri. Upper Mississippi River Conservation Committee, Rock Island, Illinois.

Havlik, M.E., and L.L. Marking. 1987. Effects of contaminants on naiad mollusks (Unionidae): a review. Unpublished report, U.S. Fish and Wildlife Service Resource Publication 164. 20 pp.

Hayes, T.B., P. Case, S. Chui, D. Chung, C. Haeffele, K. Haston, M. Lee, V.P. Mai, Y. Marjuoa, J. Parker, and M. Tsui. 2006. Pesticide mixtures, endocrine disruption, and amphibian declines: are we underestimating the impact? Environmental Health Perspectives 114:40–50.

Henley, W.F., J.W. Jones, J.L. Boyles, J.M. McLeod, and R.J. Neves. 2002. An evaluation of the suitability of the Cedar Bluff spill site for recovery of freshwater mussels, Clinch River, Tazewell County, Virginia. Final Report to the U.S. Fish and Wildlife Service, Gloucester, Virginia. 25 pp.

SSA Report – Fluted Kidneyshell 86 February 2021

Henley, W. F., M. J. Pinder, B. T. Watson, and R. J. Neves. 2013. Status of freshwater mussels in the Middle Fork Holston River, Virginia. Walkerana 16:68–80.

Henley, W.F., B.B. Beaty, and J.W. Jones. 2019. Evaluations of organ tissues from Actinonaias pectorosa collected during a mussel die-off in 2016 at Kyles Ford, Clinch River, Tennessee. Journal of Shellfish Research 38:681-696.

Hickman, M.E. 1937. A contribution to the knowledge of the molluscan fauna of east Tennessee. Masters thesis, University of Tennessee, Knoxville, Tennessee. 165 pp., 104 plates.

Higgins, J.M., and W.G. Brock. 1999. Overview of reservoir release improvements at 20 TVA dams. Journal of Energy Engineering 125:1–17.

Hubbard, W.D., D.C. Jackson, and D.J. Ebert. 1993. Channelization. Pp.135–155 in: E.F. Bryan and D.A. Rutherford, eds. Impacts on warm-water streams: guidelines for evaluation. Warmwater Stream Committee, Southern Division, American Fisheries Society, Little Rock, Arkansas.

Hubbs, D. 2002. Monitoring and management of endangered mussels. 2001-02 Annual Report Project 7365, Tennessee Wildlife Resources Agency, Nashville, Tennessee. 3 pp.

Hubbs, D.W. 2016. 2015 Duck River Quantitative Mussel Survey. Tennessee Wildlife Resources Agency Fisheries Division Report 16-06. 59 pp.

Hubbs, D. 2019. 2018 Annual Mussel Recovery Activity Report for Project 7775. Tennessee Wildlife Resources Agency Fisheries Division Report 19-05. 79 pp.

Hubbs, D. 2019. Personal Communication, November 19, 2019.

Integrated Taxonomic Information System. 2019. Available at: https://www.itis.gov/servlet/ SingleRpt/ SingleRpt?search_topic= TSN&search _value=800 51#null (accessed 6/1/2019).

International Panel on Climate Change (IPCC). 2014. Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing Team, R.K. Pachauri and L.A. Meyer (eds.)]. IPCC, Geneva, Switzerland, 151 pp.

Irwin, K.L. 2018. Freshwater Mussels (Bivalvia: Unionidae) of the Harpeth River Drainage and the Upper and Middle Duck River Tributaries, Tennessee. Master's Thesis, University of Tennessee. 131 pp.

Isom, B.G., and P. Yokley, Jr. 1968. The mussel fauna of the Duck River in Tennessee, 1965. The American Midland Naturalist 80:34-42.

SSA Report – Fluted Kidneyshell 87 February 2021

Jacobson, P.J., R.J. Neves, D.S. Cherry, and J.L. Farris. 1997. Sensitivity of glochidial stages of freshwater mussels (Bivalvia: Unionidae) to Copper. Environmental Toxicology and Chemistry 16:2384–2392.

Johnson, M.S., W.F. Henley, R.J. Neves, J.W. Jones, R.S. Butler, and S.D. Hanlon. 2012. Freshwater mussels of the Powell River, Virginia and Tennessee: abundance and distribution in a biodiversity hotspot. Walkerana 15:83–98.

Johnson, P. 2018. U.S. Fish and Wildlife Service assistance with propagation, reintroduction, research, and monitoring of federally listed mollusks in Alabama. Final report. 262 pp.

Kanehl, P. and J.Lyons. 1992. Impacts of in-stream sand and gravel mining on stream habitat and fish communities, including a survey on the Big Rib River, Marathon County, Wisconsin. Wisconsin Department of Natural Resources Research Report 155, Madison, 32 pp.

Kentucky Department of Fish and Wildlife Resources (KDFWR). 2013. Kentucky's Comprehensive Wildlife Conservation Strategy. KDFWR, Frankfort, Kentucky. Available from: http://fw.ky.gov/WAP/Pages/Default.aspx (Date updated 2/5/2013).

Kentucky Department for Environmental Protection (KDEP). 2014. Integrated Report to Congress on the condition of water resources in Kentucky, 2014, volume 1. Division of Water, Frankfort, Kentucky, 104 pp. + appendices.

Kentucky Department for Environmental Protection (KDEP). 2018. Integrated Report to Congress on the Condition of Water Resources in Kentucky, 2016 Assessment Results with Emphasis on the Big Sandy, Little Sandy, Tygarts River and Kentucky River Basin Management Units and a Statewide Update. Division of Water, Frankfort, Kentucky, 156 pp. + appendices.

Kentucky Nature Preserves (KNP). 2019. Endangered, Threatened, and Special Concern Plants, Animals, and Natural Communities of Kentucky. Office of Kentucky Nature Preserves, Kentucky Energy and Environment Cabinet, Frankfort, Kentucky. 20 pp.

Keller, A.E., and M. Lydy. 1997. Biomonitoring and the hazards of contaminants to freshwater mollusks. Unpublished report in: Freshwater mollusks as indicators of water quality: a workshop. U.S. Geological Survey Biological Resources Division and National Water Quality Assessment Program.

Kolpin, D.W., E.T. Furlong, M.T. Meyer, E.M. Thurman, S.D. Zaugg, L.B. Barber, and H.T.Buxton. 2002. Pharmaceuticals, hormones, and other organic wastewater contaminants in U.S. streams, 1999–2000: a national reconnaissance. Environmental Science and Technology 36:1202–1211.

Kondolf, G.M. 1997. Hungry water: Effects of dams and gravel mining on river channels. Environmental Management 21:533–551.

SSA Report – Fluted Kidneyshell 88 February 2021

Lasier, P.J., M.L. Urich, S.M Hassan, W.N. Jacobs, R.B. Bringolf, K.M. Owens. 2016. Changing agricultural practices: Potential consequences to aquatic organisms. Environmental Monitoring and Assessment 188:1-17.

Lawler, J.J., D.J. Lewis, E. Nelson, A.J. Plantinga, S. Polasky, J.C. Withey, D.P. Helmers, S. Martinuzzi, D. Pennington, and V.C. Radeloff. 2014. Projected land-use change impacts on ecosystem services in the United States. Proceedings of the National Academy of Sciences 111:7492-7497.

Luo, M. 1993. Host fishes of four species of freshwater mussels and development of an immune response. Masters thesis, Tennessee Technological University, Cookeville, Tennessee. 32 pp.

Martin, E. and C. Apse. 2014. Northeast Aquatic Connectivity: An Assessment of Dams on 10 Northeastern Rivers. The Nature Conservancy and Northeast Association of Fish and Wildlife Agencies. Brunswick, Maine. 102 pp.

McLeod, J.M., H.L. Jelks, S. Pursifull, and N.A. Johnson. 2017. Characterizing the early life history of an imperiled freshwater mussel (Ptychobranchus jonesi) with host-fish determination and fecundity estimation. Freshwater Science 36:338-350.

McGinley, E.J, R.L Raesly, and W.L. Seddon. 2013. The effects of embeddedness on the seasonal feeding of mottled sculpin. The American Midland Naturalist 170:213-228.

McGregor, M.A., J. Culp, A.C. Shepard, and F. Vorisek. 2008. The Kentucky Department of Fish and Wildlife Resources’ (KDFWR) aquatic restoration initiative to recover endangered mussels, phase I: early stage culture and propagation of Ohio River drainage imperiled species. Annual report. Oct 1, 2007 to September 30, 2008. Kentucky Department of Fish and Wildlife Resources, Frankfort, KY. 63 pp.

McGregor, M. 2019. Personal communication, October, 2019.

McMahon, R.F. and A.E. Bogan. 2001. Mollusca: Bivalvia. Pp 331—429. In J.H. Thorpeand A.P. Covich (editors). Ecology and classification of North American Freshwater Invertebrates. Second Edition. Academic Press, New York.

Mellinger, P.J. 1972. The comparative metabolism of cadmium, mercury, and zinc as environmental contaminants in the freshwater mussel, Margaritifera margaritifera. Ph.D. dissertation, Oregon State University, Corvallis. 129 pp.

Messinger, T. and D.B. Chambers. 2001. Fish communities and their relation to environmental factors in the Kanawha River basin, West Virginia, Virginia, and North Carolina, 1997- 98. Charleston, WV: U.S. Geological Survey. Water-Resources Investigations Report 01-4048.

SSA Report – Fluted Kidneyshell 89 February 2021

Moles, K.R., N.T. Welte, and J.B. Layzer. 2007. Mussel fauna of the Wolf River, Fentress and Pickett counties, Tennessee. Journal of the Tennessee Academy of Science 82:77–82.

Mugade, U.R. and J.B. Sapkale. 2015. Influence of aggradation and degradation on river channels: A review. International Journal of Engineering and Technical Research 3:209-212.

Mummert, A.K., R.J. Neves, T.J. Newcomb, and D.S. Cherry. 2003. Sensitivity of juvenile freshwater mussels (Lampsilis fasciola, Villosa iris) to total and un-ionized ammonia. Environmental Toxicology and Chemistry 22:2545-2553.

Naimo, T.J. 1995. A review of the effects of heavy metals on freshwater mussels. Ecotoxicology 4:341–362.

National Drought Mitigation Center (NDMC). 2019. https://droughtmonitor.unl.edu/ (Accessed June 4, 2019).

North Carolina Aquatic Nuisance Species Management Plan Committee. 2015. North Carolina Aquatic Nuisance Species Management Plan. Raleigh, NC. 96 pp.

North Carolina Interagency Leadership Team (NCILT). 2012. Climate Ready North Carolina: Building a Resilient Future. Raleigh, NC. 152 pp.

Neves, R. J., and P. L. Angermeier. 1990. Habitat alteration and its effects on native fishes in the upper Tennessee River system, east‐central USA. Journal of Fish Biology 37:45-52.

Neves, R.J., A.E. Bogan, J.D. Williams, S.A. Ahlstedt, and P.W. Hartfield. 1997. Status of Aquatic Mollusks in the Southeastern United States: A Downward Spiral of Diversity; Chapter 3 (Pp.44-86) in Aquatic Fauna in Peril: The Southeastern Perspective, edited by G.W. Benz and D.E. Collins (1997), Special Publication 1. Southeast Aquatic Research Institute. Lenz Design and Communications, Decatur, Georgia. 554 pp.

Newton, T.J. 2003. The effects of ammonia and freshwater unionid mussels. Environmental Toxicology and Chemistry 22:2543-2544.

Newton, T.J., J.W. Allran, J.A. O’Donnell, M.R. Bartsch, and W.B. Richardson. 2003. Effects of ammonia on juvenile unionid mussels (Lampsilis cardium) in laboratory sediment toxicity tests. Environmental Toxicology and Chemistry 22:2554–2560.

Newton, T.J. and W.G. Cope. 2007. Biomarker responses of unionid mussels to environmental contaminants. Pp. 257-284 in: J.L. Farris and J.H. Van Hassel, eds. Freshwater Bivalve Ecotoxicology. CRC Press, Boca Raton, Florida.

Nobles, T. and Zhang, Yixin. 2011. Biodiversity Loss in Freshwater Mussels: Importance, Threats, and Solutions. Chapter 6 (pp. 137–162) in Biodiversity Loss in a Changing Planet, edited by O. Grillo and G. Venora (2011). InTech, Rijeka, Croatia. 328 pp.

SSA Report – Fluted Kidneyshell 90 February 2021

Ortmann, A.E. 1912. Notes upon the families and genera of the naiades. Annals of the Carnegie Museum 8:222-365.

Ortmann, A.E. 1918. The nayades (freshwater mussel) of the upper Tennessee drainage. With notes on synonymy and distribution. Proceedings of the American Philosophical Society 57:521–626.

Ortmann, A.E. 1924. The naiad-fauna of Duck River in Tennessee. American Midland Naturalist 9:18–62.

Ortmann, A.E. 1925. The naiad fauna of the Tennessee River system below Walden Gorge. American Midland Naturalist 9:321–372.

Ohio State University Museum Mollusk Collection (OSUM). 2018. Museum Database Query by Michael Compton.

Parmalee, P.W., and A.E. Bogan. 1998. The freshwater mussels of Tennessee. The University of Tennessee Press, Knoxville, Tennessee. 328 pp.

Parmalee, P.W., and H.D. Faust. 2006. Diversity and relative abundance of preimpoundment freshwater mussel (Bivalvia: Unionidae) populations in the lower Holston River, Tennessee. Journal of the Tennessee Academy of Science 81(3-4):74-77.

Parmalee, P.W., and R.R. Polhemus. 2004. Prehistoric and pre-impoundment populations of freshwater mussels (Bivalvia: Unionidae) in the South Fork Holston River, Tennessee. Southeastern Naturalist 3:231-240.

Patnode, K.A., R.M. Anderson, L. Zimmermann, E. Hittle, and J.W. Fulton. 2015. Effects of high salinity wastewater discharges on unionid mussels in the Allegheny River, Pennsylvania. Journal of Fish and Wildlife Management 6:55–70.

Phipps, A., M. Hyde, and J. Jones. 2018. Monitoring Freshwater Mussels at Population Restoration Sites in the Upper Tennessee River Basin, Tennessee, and Virginia. Report submitted to USFWS Tennessee Field Office, Cookeville, Tennessee. 63 pp.

Pilsbry, H.A., and S.N. Rhoads. 1896. Contributions to the zoology of Tennessee. Proceedings of the Academy of Natural Sciences of Philadelphia 48:487-506.

Poff, N.L., M.M. Brinson, and J.W. Day, Jr. 2002. Aquatic ecosystems & Global climate change: Potential Impacts on Inland Freshwater and Coastal Wetlands Ecosystems in the United States. Pew Center on Global Climate Change. 56 pp.

Price, J.E., C.E. Zipper, J.W. Jones, and C.T. Franck. 2014. Water and sediment quality in the Clinch River, Virginia and Tennessee, USA, over nearly five decades. Journal of the American Water Resources Association 50:837-858.

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Redford, K.H., G. Amoto, J. Baillie, P. Beldomenico, E.L. Bennett, N. Clum, R. Cook, G. Fonseca, S. Hedges, F. Launay, S. Lieberman, G.M. Mace, A. Murayama, A. Putnam, J.G. Robinson, H. Rosenbaum, E.W. Sanderson, S.N. Stuart, P. Thomas, and J. Thorbjarnarson. 2011. What does it mean to successfully conserve a (vertebrate) species? Bioscience 61:39-48.

Reed, M.P. 2014. Freshwater Mussels (Bivalvia: Margaritiferidae and Unionidae) of the Buffalo River Drainage, Tennessee. Master’s Thesis, University of Tennessee. 89 pp.

Reed, M.P., G.R. Dinkins, and S.A. Ahlstedt. 2019. Freshwater mussels (Bivalvia: Margaritiferidae and Unionidae) of the Buffalo River drainage, Tennessee. Southeastern Naturalist 18:346-372.

Ren, W., Y. Zhong, J. Meligrana, B. Anderson, W.E. Watt, J. Chen, and H. Leung. 2003. Urbanization, land use, and water quality in Shanghai: 1947–1996. Environment International 29:649-659.

Richard, J. 2019. Personal communication (email correspondence) regarding mussel die-offs in the Clinch River. U.S. Fish and Wildlife Service, Abington, Virginia.

Richard, J.C., E. Leis, C.D. Dunn, R. Agbalog, D. Waller, S. Knowles, J. Putnam, and T.L. Goldberg. 2020. Mass mortality in freshwater mussels (Actinonaias pectorosa) in the Clinch River, USA, linked to a novel densovirus. Scientific Reports (2020) 10:14498.

Roell, M.J. 1999. Sand and gravel mining in Missouri stream systems: aquatic resource effects and management alternatives. Missouri Department of Conservation, Columbia, 25 pp.

Say, T. 1825. Descriptions of some new species of fresh water and land shells of the United States. Journal of the Academy of Natural Sciences of Philadelphia 5(3-4):119-131.

Scheller, J.L. 1997. The effects of dieoffs of Asian Clams (Corbidula fluminea) on Native Freshwater Mussels (Unionidae). Master of Science thesis. Virginia Polytechnic Institute and State University. 100 pp.

Schuster, G.A., R.S. Butler, and D.H. Stansbery. 1989. A survey of the Unionids (Bivalvia: Unionidae) of Buck Creek, Pulaski County, Kentucky. Transactions of the Kentucky Academy of Sciences 50(1-2):79-85.

Scott, E.M., Jr., K.D. Gardner, D.S. Baxter, and B.L. Yeager. 1996. Biological and water quality responses in tributary tailwaters to dissolved oxygen and minimum flow improvements. Tennessee Valley Authority, Norris, Tennessee. 211 pp.

Shaffer, M.L. and B.A. Stein. 2000. Safeguarding our precious heritage. In: Stein B.A., L.S. Kutner, and J.S. Adams, eds. Precious Heritage: the status of biodiversity in the United States. New York: Oxford University Press: pp. 301-321.

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Simberloff, D. 1996. Impacts of introduced species in the United States. Consequences 2:13- 22.

Smith, D.R., N.L. Allan, C.P. McGowan, J.A. Szymanski, S.R. Oetker, and H.M. Bell. 2018. Development of a species status assessment process for decisions under the U.S. Endangered Species Act. Journal of Fish and Wildlife Management 9(1): 302-320. Strayer, D.L. and H.M. Malcolm. 2012. Causes of recruitment failure in freshwater mussel populations in southeastern New York. Ecological Applications 22:1780-1790.

Strayer, D.L., J.A. Downing, W.R. Haag, T.L. King, J.B. Layzer, T.J. Newton, and S.J. Nichols. 2004. Changing perspectives on pearly mussels, North America’s most imperiled animals. BioScience 54:429-439.

Strayer, D.L. 2008. Freshwater mussel ecology: a multifactor approach to distribution and abundance. Vol. 1. University of California Press. 216 pp.

Sutherland, A.B., J.L. Meyer, and E.P. Gardiner. 2002. Effects of land cover on sediment regime and fish assemblage structure in four southern Appalachian streams. Freshwater Biology (2002) 47:1791-1805.

Tear, T.H, P. Kareiva, P.L. Angermeier, P. Comer, B. Czech, R. Kautz, L. Landon, D. Mehlman, K. Murphy, M. Ruckelshaus, J.M. Scott, and G. Wilhere. 2005. How much is enough? The recurrent problem of setting measurable objectives in conservation. BioScience 55:835-849.

Tennessee Department of Environment and Conservation (TDEC). 2014. 2014 305(b) report: the status of water quality in Tennessee. Division of Water Pollution Control, Nashville, Tennessee. 114 pp.

Tennessee Department of Environment and Conservation (TDEC). 2017. Proposed Final year 2016 303(d) list. Division of Water Resources, Nashville, Tennessee. 223 pp.

Tennessee Valley Authority (TVA). 2020. Hydroelectric. Available at: https://www.tva.gov /Energy/Our-Power-System/Hydroelectric (accessed 10/7/2019).

Tennessee State Wildlife Resources Agency (TWRA). 2015. Tennessee State Wildlife Action Plan 2015. Nashville, Tennessee. 506 pp.

Terando, A.J., J. Costanza, C. Belyea, R.R. Dunn, A. McKerrow, and J.A. Collazo. 2014. The Southern Megalopolis: Using the Past to Predict the Future of Urban Sprawl in the Southeast U.S. PLoS ONE 9(7): e102261.

U.S. Army Corps of Engineers. 2019. National inventory of dams: U.S. Army Corps of Engineers. Available at: https://nid.sec.usace.army.mil/ords/f?p=105:1:::::: (accessed 10/7/2019).

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U.S. Environmental Protection Agency. 1985. Ambient water quality criteria for ammonia - 1984. EPA-440/5-85-001. National Technical Information Service, Springfield, VA.

U.S. Environmental Protection Agency (EPA), 2010, Level III ecoregions of the continental United States (revision of Omernik, 1987): Corvallis, Oregon, USEPA National Health and Environmental Effects Research Laboratory, Map M-1, various scales.

U.S. Environmental Protection Agency (EPA). 2017. 303(d) Listed Impaired Waters NHDPlus Indexed Dataset with Program Attributes. Available at https://www.epa.gov/waterdata/ waters-geospatialdatadownloads#303dListedImpairedWaters (accessed 10/2/2017).

U.S. Fish and Wildlife Service (USFWS). 2013a. Endangered and threatened wildlife and plants; Endangered species status for the Fluted Kidneyshell and Slabside Pearlymussel. Federal Register 78:59269-59287.

U.S. Fish and Wildlife Service (USFWS). 2013b. Endangered and threatened wildlife and plants; Designation of Critical Habitat for the Fluted Kidneyshell and Slabside Pearlymussel. Federal Register 78:59556-59620.

U.S. Fish and Wildlife Service (USFWS). 2016. USFWS Species Status Assessment Framework: An integrated analytical framework for conservation. Version 3.4 dated August 2016.

US Global Climate Change Research Program (USGCRP). 2017: Climate Science Special Report: Fourth National Climate Assessment, Volume I [Wuebbles, D.J., D.W. Fahey, K.A. Hibbard, D.J. Dokken, B.C. Stewart, and T.K. Maycock (eds.)]. U.S. Global Change Research Program, Washington, DC, USA, 470 pp.

U.S. Geological Survey (USGS). 2014. Effects of Urbanization on Stream Ecosystems. http://water.usgs.gov/nawqa/urban/ (Accessed: October 5, 2016).

Van der Shalie, H. 1973. The mollusks of the Duck River drainage in central Tennessee. Sterkiana 52:45-56.

Valenti, T.W., D.S. Cherry, R.J. Neves, and J. Schmerfeld. 2005. Acute and chronic toxicity of mercury to early life stages of the rainbow mussel, Villosa iris (Bivalvia: Unionidae). Environmental Toxicology and Chemistry 24:1242–1246.

Virginia Department of Game and Inland Fisheries (VDGIF). 2020. Special Status Faunal Species in Virginia. Available at: https://www.dgif.virginia.gov/wp-content/uploads/ media/virginia-threatened-endangered-species.pdf.

Virginia Department of Game and Inland Fisheries (VDGIF). 2015. Virginia Comprehensive Wildlife Conservation Strategy. Available at: hhtp://www.bewildvirginia.org.

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Virginia Department of Environmental Quality. 2018. Virginia Water Quality Assessment 305(b)/303(d) integrated report 2016. VDEQ, Richmond, Virginia. 2309 pp.

Wang, N., R.J. Erikson, C.G. Ingersoll, C.D. Ivey, E.L. Brunson, T. Augspurger, and M.C. Barnhart. 2008. Environmental Toxicology and Chemistry 27(5): 1141-1146.

Waters, T.F. 1995. Sediment in streams: sources, biological effects, and control: American Fisheries Society Monograph 7, 251 pp.

Watters, G.T. 2000. Freshwater mussels and water quality: A review of the effects of hydrologic and instream habitat alterations. Proceedings of the First Freshwater Mollusk Conservation Society Symposium, 1999. Pp. 261-274.

Wheeler, A.P., P.L. Angermeier, and A.E. Rosenberger. 2005. Impacts of new highways and subsequent landscape urbanization on stream habitat and biota. Reviews in Fishery Science 13:141–164.

Williams, J.D., A.E. Bogan, and J.T. Garner. 2008. Freshwater mussels of Alabama & the Mobile Basin in Georgia, Mississippi, & Tennessee. University of Alabama Press, Tuscaloosa, Alabama. 908 pp.

Williams, J.D., A.E. Bogan, R.S. Butler, K.S. Cummings, J.T. Garnier, J.L. Harris, N.A. Johnson, and G.T. Watters. 2017. A revised list of the freshwater mussels (Mollusca: Bivalvia: Unionida) of the United States and Canada. Freshwater Mollusk Biology and Conservation 20:33-58.

Williamson, E.B. 1905. Odonata, Astacidae and Unionidae collected along the Rockcastle River at Livingston, Kentucky. The Ohio Naturalist 5:309-312.

Wilson, C.O. 2015. Land use/land cover water quality nexus: quantifying anthropogenic influences on surface water quality. Environmental Monitoring and Assessment 187:424.

Wilson, C.B., and H.W. Clark. 1914. The mussels of the Cumberland River and its tributaries. Report to the U.S. Commission of Fisheries for 1912, Special Papers. 63 pp.

Winston M.R, C.M. Taylor, and J. Pigg. 1991. Upstream extirpation of four minnow species due to damming of a prairie stream. Transactions of the American Fisheries Society 120:98–105.

Wisniewski, J. 2020. 2020 Duck River quantitative mussel survey. Fisheries Report 16-06. Tennessee Wildlife Resources Agency, Nashville, TN. 39 pp.

Wu, M., M. Quirindongo, J. Sass, A. Wetzler. 2010. Still poisoning the well: Atrazine continues to contaminate surface water and drinking water in the United States. Natural Resources Defense Council, Washington, D.C. USA.

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Yan, Y., X. Xiang, L. Chu, Y. Zhan, and C. Fu. 2011. Influences of local habitat and stream spatial position on fish assemblages in a dammed watershed, the Qingyi Stream, China. Ecology of Freshwater Fishes 20:199-208.

Yang, L., S. Jin, P. Danielson. C.G. Homer, L. Gass, S.M. Bender, A. Case, C. Costello, J.A. Dewitz, J.A. Fry, M. Funk, B.J. Granneman, G.C. Liknes, M.B. Rigge, and G. Xian. 2018. A new generation of the United States National Land Cover Database— Requirements, research priorities, design, and implementation strategies. ISPRS Journal of Photogrammetry and Remote Sensing 146:108-123.

Yeager, M.M., D.S. Cherry, and R.J. Neves. 1994. Feeding and burrowing behaviors of juvenile rainbow mussels, Villosa iris (Bivalvia: Unionidae). Journal of the North American Benthological Society 13:217-222.

Zipper, C.E., B. Beaty, G.C. Johnson, J.W. Jones, J.L. Krstolic, B.J.K. Ostby, W.J. Wolfe, and P.Donovan. 2014. Freshwater mussel population status and habitat quality in the Clinch River, Virginia and Tennessee, USA: A featured collection. Journal of the American Water Resources Association 50:807-819.

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APPENDIX A

Peer Review Summary A. Peer Review Method:

The draft SSA was sent to three people requesting their peer review: Gerry Dinkins (University of Tennessee), Wendell Haag (U.S. Forest Service), and Mike Pinder (Virginia Department of Game and Inland Fisheries). Gerry Dinkins and Wendell Haag responded with comments. Mike Pinder did not respond.

B. Peer Review Charge:

Melissa Lombardi in the Service’s Arkansas Field Office assisted in completing the independent peer review and asked peer reviewers to read the SSA and provide any comments, both editorial and content related. The Service did not ask peer reviewers to comment on the recommendation regarding listing status.

C. Summary of Peer Review Comments/Report and Responses:

• Both peer reviewers provided editorial comments and suggestions for clarification.

• Wendell Haag informed us of a weathered Fluted Kidneyshell specimen he collected from the Red River, Tennessee in 2019. This new information would add an additional, extirpated population to the populations discussed in this SSA. Because this information was provided after the SSA had been drafted and the discussion of the current status and analyses of future conditions in the draft was still relevant without this new information, we did not include it in this SSA. We will include it in the next 5-Year Review for the species due in fiscal year 2021.

• Gerry Dinkins provided information about archeological records that were not considered in the draft SSA. Additionally, Haag stated that Parmalee and Bogan (1998) included a record from Caney Fork that was not included in the draft SSA. We believe that this is also an archeological record. To address these comments, we added text to explain that we did not use archeological records to delineate populations in the SSA, because, while highly suggestive, they do not definitively associate the species to a particular watershed.

• Haag suggested that Fluted Kidneyshell populations in the Cumberland River drainage and the Tennessee River drainages may actually represent two separate, but closely related, species, as has been recently discovered for some other aquatic species in those drainages. A genetics study investigating this question is currently ongoing at Central Michigan University. We did not include this work in the SSA, but have included it as a recovery activity in the Recovery Plan.

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• Haag commented that the list of threats to the species was exhaustive and that there is not strong evidence that correlates most of those threats to Fluted Kidneyshell declines. He emphasized that the threats to freshwater mussels are largely unknown. We added text to the SSA making it clear that we were including threats to aquatic species in general and that the effects of these potential threats to the Fluted Kidneyshell are poorly understood. Dinkins commented that the text about ammonia is somewhat misleading, because it implies that juvenile mussels are more sensitive to ammonia than glochidia, and Augsperger et al. (2003) found the opposite. We removed the specific data that led to the confusion and summarized the conclusion from that study. Haag informed us of a recent study that showed a negative correlation between juvenile Fluted Kidneyshell growth and Asian clam abundance. We added this preliminary finding to the SSA. Dinkins stated that the die-offs in the Clinch River coincided with prolonged dry weather. We did not include this correlation in the SSA, because we are not aware of any conclusive studies attributing drought to the die-offs. The SSA states that the causes of the die-offs are unknown and references ongoing research investigating the causes. Dinkins provided additional information about Fluted Kidneyshells reintroduced below Calderwood Dam that we added to our discussion of conservation programs and efforts.

• Haag generally supported the criteria for assessing current conditions and analysis used for projecting future conditions. He commented that the SSA underemphasizes the true decline of the Fluted Kidneyshell, because it assesses the presence or absence of populations, rather than declines in population numbers. We did not assess population trends in the SSA, because quantitative survey data for the Fluted Kidneyshell from multiple sites is not available. He commented that some Fluted Kidneyshell populations have been extirpated or nearly extirpated in streams that are not on the 303(d) list or not in watersheds dominated by agriculture, two criteria we used to assess the habitat condition of populations. We added text reiterating that the effects of many specific threats to the Fluted Kidneyshell are poorly understood and added text acknowledging that there may be factors other than those we assessed that influence the condition of Fluted Kidneyshell populations.

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APPENDIX B

Table A.1. Current Fluted Kidneyshell population element scores.

Greatest # of # of # of Live/FD Assessed distance of tributaries Total Occupied individuals Population

Score Score continuous Score plus Score Score HUC10s Extent since 2004 Elements Continuity Continuity Complexity Abundance Abundance habitat (km) mainstem Populations Cumberland Obey 1 1 25 1 5.0 1 1 1 1.0 Low Buck Creek 1 1 35 1 20.0 1 1 1 1.0 Low Big South Fork 2 2 55 1 7.1 1 3 3 1.8 Moderate Tennessee Upper Duck 2 2 ~7000* 3 43.0 2 1 1 2.0 Moderate Lower Elk 1 1 141* 2 1.0 1 1 1 1.3 Low Nolichucky 2 2 ~6300* 3 2.0 1 1 1 1.8 Moderate NF Holston 2 2 836 3 83.0 2 1 1 2.0 Moderate SF Holston 1 1 1 1 2.0 1 1 1 1.0 Low Clinch 8 3 >10,000 3 160.0 3 4 3 3.0 High Powell 2 2 35 1 45.0 2 1 1 1.5 Moderate * Specimens were reintroduced and translocated from Clinch River stock.

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Table A.2. Current Fluted Kidneyshell habitat element scores.

Reservoir % watershed Assessed km of impaired influence Total development / Habitat

waterbodies Score Score (Qualitatively Score Score agriculture Elements Assessed) Connectivity Connectivity Water Quality Water Habitat Quality Quality Habitat Populations Cumberland Harpeth 604 0 39 2 1 1.0 Low Obey 185 0 25 2 0 0.7 Low Buck Creek 29 3 34 2 0 1.7 Moderate Big South Fork 145 1 11 3 0 1.3 Low Rockcastle 60 2 23 3 0 1.7 Moderate Upper Cumberland 48 2 30 2 0 1.3 Low Tennessee Buffalo 114 1 23 3 2 2.0 Moderate Upper Duck 655 0 56 1 1 0.7 Low Pickwick Lake 158 1 40 2 0 1.0 Low Lower Elk 230 0 48 2 2 1.3 Low Upper Elk 692 0 49 2 0 0.7 Low Wheeler Lake 367 0 51 1 0 0.3 Low Guntersville Lake 153 1 37 2 0 1.0 Low Lower French Broad 338 0 29 2 0 0.7 Low Nolichucky 1,191 0 39 2 3 1.7 Moderate Holston 668 0 41 2 0 0.7 Low NF Holston 40 2 27 2 3 2.3 Moderate SF Holston 653 0 44 2 2 1.3 Low Clinch 571 0 26 2 2 1.3 Low Powell 314 0 19 3 2 1.7 Moderate SSA Report – Fluted Kidneyshell 100 February 2021

Table A.3. Projected Fluted Kidneyshell resiliency under Scenario 1 (Status Quo). Declines from current condition are indicated in bold red font.

Projected Projected Projected Population Habitat Population Score Score Score Score Score Score Score Extent Elements Elements Resiliency Continuity Continuity Abundance Abundance Total Score Total Score Complexity Complexity Connectivity Connectivity Water Quality Water Populations Habitat Quality Cumberland Harpeth 0 0 0 0 0 Extirpated 0 2 1 1.0 Low Extirpated Obey 0 0 0 0 0 Extirpated 0 2 0 0.7 Low Extirpated Buck Creek 0 0 0 0 0 Extirpated 2 2 0 1.3 Low Extirpated Big South Fork 1 1 1 2 1.3 Low 1 3 0 1.3 Low Low Rockcastle 0 0 0 0 0 Extirpated 2 3 0 1.7 Moderate Extirpated Upper Cumberland 0 0 0 0 0 Extirpated 2 2 0 1.3 Low Extirpated Tennessee Buffalo 0 0 0 0 0 Extirpated 1 3 2 2.0 Moderate Extirpated Upper Duck 2 2 1 1 1.5 Moderate 0 1 1 0.7 Low Low Pickwick 0 0 0 0 0 Extirpated 1 2 0 1.0 Low Extirpated Lower Elk 0 0 0 0 0 Extirpated 0 2 2 1.3 Low Extirpated Upper Elk 0 0 0 0 0 Extirpated 0 2 0 0.7 Low Extirpated Wheeler Lake 0 0 0 0 0 Extirpated 0 1 0 0.3 Low Extirpated Guntersville Lake 0 0 0 0 0 Extirpated 1 2 0 1.0 Low Extirpated Lower French Broad 0 0 0 0 0 Extirpated 0 2 0 0.7 Low Extirpated Nolichucky 1 2 1 1 1.3 Low 0 2 3 1.7 Moderate Low Holston 0 0 0 0 0 Extirpated 0 2 0 0.7 Low Extirpated NF Holston 2 3 2 1 2.0 Moderate 2 2 3 2.3 Moderate Moderate SF Holston 0 0 0 0 0 Extirpated 0 2 2 1.3 Low Extirpated Clinch 3 2 3 3 3.0 High 0 2 2 1.3 Low Moderate Powell 2 1 2 1 1.5 Moderate 0 3 2 1.7 Moderate Moderate

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Table A.4. Projected Fluted Kidneyshell resiliency under Scenario 2 (Pessimistic). Declines from current condition are indicated in bold red font.

Projected Projected Projected Population Habitat Population Score Score Score Score Score Score Score Extent Elements Elements Resiliency Continuity Continuity Abundance Abundance Total Score Total Score Complexity Connectivity Connectivity Water Quality Water Populations Habitat Quality Cumberland Harpeth 0 0 0 0 0 Extirpated 0 2 1 1.0 Low Extirpated Obey 0 0 0 0 0 Extirpated 0 2 0 0.7 Low Extirpated Buck Creek 0 0 0 0 0 Extirpated 1 2 0 1.0 Low Extirpated Big South Fork 2 1 1 2 1.5 Moderate 0 3 0 1.0 Low Low Rockcastle 0 0 0 0 0 Extirpated 2 2 0 1.3 Low Extirpated Upper Cumberland 0 0 0 0 0 Extirpated 2 2 0 1.3 Low Extirpated Tennessee Buffalo 0 0 0 0 0 Extirpated 1 2 2 1.7 Moderate Extirpated Upper Duck 0 0 0 0 0 Extirpated 0 1 1 0.7 Low Extirpated Pickwick 0 0 0 0 0 Extirpated 0 2 0 0.7 Low Extirpated Lower Elk 0 0 0 0 0 Extirpated 0 1 2 1.0 Low Extirpated Upper Elk 0 0 0 0 0 Extirpated 0 1 0 0.3 Low Extirpated Wheeler Lake 0 0 0 0 0 Extirpated 0 1 0 0.3 Low Extirpated Guntersville Lake 0 0 0 0 0 Extirpated 0 2 0 0.7 Low Extirpated Lower French Broad 0 0 0 0 0 Extirpated 0 2 0 0.7 Low Extirpated Nolichucky 0 0 0 0 0 Extirpated 0 2 3 1.7 Moderate Extirpated Holston 0 0 0 0 0 Extirpated 0 2 0 0.7 Low Extirpated NF Holston 1 1 1 1 1.0 Low 1 2 3 2.0 Moderate Low SF Holston 0 0 0 0 0 Extirpated 0 1 2 1.0 Low Extirpated Clinch 2 1 1 1 1.3 Low 0 2 2 1.3 Low Low Powell 2 1 1 1 1.3 Low 0 3 2 1.7 Moderate Low

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Table A.5. Projected Fluted Kidneyshell resiliency under Scenario 3 (Optimistic). Improvements from current condition are indicated in bold green font.

Projected Projected Projected Population Habitat Population Score Score Score Score Score Score Score Extent Elements Elements Resiliency Continuity Continuity Abundance Abundance Total Score Total Score Complexity Connectivity Connectivity Water Quality Water Populations Habitat Quality Cumberland Harpeth 0 0 0 0 0 Extirpated 0 2 1 1.0 Low Extirpated Obey 2 2 1 2 1.8 Moderate 2 2 0 1.3 Moderate Moderate Buck Creek 1 1 1 1 1.0 Low 3 2 0 1.7 Moderate Low Big South Fork 2 1 1 3 1.8 Moderate 2 3 0 1.7 Moderate Moderate Rockcastle 1 2 1 1 1.3 Low 2 3 0 1.7 Moderate Low Upper Cumberland 0 0 0 0 0 Extirpated 2 2 0 1.3 Low Extirpated Tennessee Buffalo 0 0 0 0 0 Extirpated 1 3 2 2.0 Moderate Extirpated Upper Duck 2 3 2 2 2.3 Moderate 1 1 1 1.0 Low Moderate Pickwick 0 0 0 0 0 Extirpated 1 2 0 1.0 Low Extirpated Lower Elk 1 3 1 1 1.5 Moderate 1 2 2 1.7 Moderate Moderate Upper Elk 0 0 0 0 0 Extirpated 0 2 0 0.7 Low Extirpated Wheeler Lake 0 0 0 0 0 Extirpated 0 1 0 0.3 Low Extirpated Guntersville Lake 0 0 0 0 0 Extirpated 1 2 0 1.0 Low Extirpated Lower French Broad 0 0 0 0 0 Extirpated 0 2 0 0.7 Low Extirpated Nolichucky 2 3 1 1 1.8 Moderate 0 2 3 1.7 Moderate Moderate Holston 0 0 0 0 0 Extirpated 0 2 0 0.7 Low Extirpated NF Holston 3 3 2 1 2.3 Moderate 3 2 3 2.7 High Moderate SF Holston 1 2 2 1 1.5 Moderate 1 2 2 1.7 Moderate Moderate Clinch 3 3 3 3 3.0 High 1 3 2 2.0 Moderate High Powell 2 3 2 1 2.0 Moderate 1 3 2 2.0 Moderate Moderate

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