The federally endangered tan riffleshell (<I>Epioblasma florentina walkeri</I>) is restricted to only one known reproducing population, in Indian Creek, Tazewell County, Virginia. Attempts to recover this species by augmenting relic populations throughout its historic range are aided through knowledge of its population biology and requirements in culture environments. Infestations of host fish (fantail darters, <I>Etheostoma flabellare</I>), obtained from four river drainages, with tan riffleshell glochidia showed that significantly more juveniles transformed per fish from infestations on fantail darters from Indian Creek (mean = 59.22 ± 10.01) than on fantail darters from the Roanoke River (mean = 9.45 ± 10.64) (p = 0.024). Number of juveniles from fantail darters collected from Elk Garden and the South Fork Holston River were not significantly different from those of either Indian Creek fish or Roanoke River fish. These results support the hypothesis that mussel-host fish relationships are likely mediated by fish immune responses. Furthermore, this study suggests that this compatibility has resulted from coadaptation between the tan riffleshell and fantail darter populations in Indian Creek. The tan riffleshell population in Indian Creek was estimated to be 1078 adults (95% CI= 760 - 1853), using Schumacher's modification of Schnabel's maximum likelihood estimator. The sex ratio and size distribution of males and females were approximately equal. Specimen ages, determined from thin-sections of shells, showed that mussels aged by external annuli on shells likely underestimates the true ages of individuals. Appropriate culture conditions for this species were examined using juveniles of the wavyrayed lampmussel (<I>Lampsilis fasciola</I>) as a surrogate. In the first experiment, juvenile growth and survival was compared between four substratum types (fine sediment, < 120μm; fine sand, 500 μm-800 μm; coarse sand, 1000 μm-1400 μm; and mixed sediment, < 1400 μm) and two light treatments in open versus covered recirculating troughs (2.8 m). Juveniles in fine sediment substratum and covered troughs fared poorest, with 7% survival and growth to only 0.86 mm in length after 16 wk. Juveniles in mixed sediment and open troughs fared best, with 26% survival and growth to 1.09 mm after 16 wk. Additionally, juveniles in fine sand in covered troughs had significantly higher survival (23.1%) than juveniles in fine sediment (p = 0.04), and juveniles in fine sand survived consistently better between light treatments than in the other substrata. There were no significant differences among the other treatments. A second experiment was performed to determine whether juveniles were responding directly to the presence of light or whether only the increased autochthonous production improved growth and survival. One-half of each of three 2.8 m troughs were covered with 50% shade cloth, while the other sides were left open to ambient light. Additionally, the best and worst sediments from the first experiment (fine sand and fine sediment) were used again to verify the results from the previous experiment. In this case, juveniles in both sides of the troughs grew equally well, but juveniles in the open sides had significantly poorer survival (open mean: 1.78%, sd = 5.01; covered mean: 7.4%, sd = 5.01) (p = 0.046). Fine sediment yielded significantly higher growth of juveniles than fine sand (p = 0.009), with shell lengths of 2.63 mm (sd = 0.075) in fine sediment and 1.94 mm (sd = 0.102) in fine sand. The differences in survival and growth between the two experiments were attributed to differential numbers of chironomids and platyhelminths, which are predators of young juveniles. Additionally, the fine sediment was more tightly packed in the first experiment than in the second, which may have restricted movement and subsequently reduced survival. Light alone likely did not affect juvenile survival and growth; rather, it was seemingly the greater abundance of aufwuchs available as food. This hypothesis was corroborated by a juvenile behavior experiment, which showed that juveniles did not act differently when in tanks not exposed to light versus those open to ambient light. / Master of Science

The Upper Tennessee River drainage of Virginia and Tennessee, Green River drainage of Kentucky, and Cumberland River drainage of Kentucky and Tennessee are known for their freshwater mussel species diversity. These river systems harbor dense populations of freshwater mussels that have significant impacts on surrounding ecosystems; however, due to their sedentary lifestyles, freshwater mussels are particularly susceptible to many biotic and abiotic stressors. Managers strive to preserve the fragile ecosystems that include freshwater mussels and, hence, study the life-history strategies of endangered and common freshwater mussel species. The goals of this project were to inform management decision-making based on whether Leaunio ortmanni is endemic to the Green River drainage and a species distinct from Leaunio vanuxemensis based on molecular identification, estimation of genetic diversity, and morphometric analysis, and to screen for cryptic biodiversity of populations of the Cambarunio iris species complex in the Upper Tennessee, Cumberland, and Green River drainages. I used the mitochondrial DNA (mtDNA) gene from the first subunit of the NADH dehydrogenase (ND1) as a genetic marker for species-level assessment of L. ortmanni and L. vanuxemensis from the Green and Cumberland River drainages. Additional mtDNA sequences of L. ortmanni and L. vanuxemensis were added to increase sample sizes and coverage of historical distribution. A Bayesian phylogenetic analysis of mtDNA sequences did not result in monophyletic lineages for either species based on the ND1 marker. Haplotype networks of mtDNA sequences demonstrated that haplotype sharing is occurring between the two focal taxa, and also among additional taxa, all of which previously belonged to the genus Villosa. A total of eight nuclear DNA microsatellites were successfully genotyped for the two focal taxa. The nuclear DNA microsatellites showed a strong phylogeographic signal between L. ortmanni of the Green River drainage and L. vanuxemensis of the Cumberland River drainage. An assignment-test based analysis in program STRUCTURE and a phylogenetic tree constructed using Nei's D genetic distance indicated well-differentiated populations across the two drainages. Additionally, the nuclear DNA microsatellite analysis showed a recent loss of genetic diversity across all populations, including when populations were pooled together at the sub-basin level. Further delineation of the focal taxa was assessed using geometric morphometrics and decision tree and random forest analyses. Decision tree and random forest analyses identified periostracum color, nacre color, overall shape, and sex to be distinguishing factors for field identification of L. ortmanni and L. vanuxemensis. Geometric morphometrics comparing species, shape, and drainage showed clear differentiation in shell shape between L. ortmanni and L. vanuxemensis. This study was able to delineate these two taxa, showing that L. ortmanni and L. vanuxemensis are separate species, and that L. ortmanni warrants listing under the Endangered Species Act. Management actions should focus on broodstock collection and propagation strategies to increase genetic diversity within established populations. Additionally, propagation and augmentation should look to reintroduce populations of L. ortmanni into its historical geographic range in unoccupied sections of the mainstem Green River. In addition, I assessed genetic diversity and differentiation again using ND1 and eight nuclear DNA microsatellite loci, and morphological differences among different shell forms of C. iris in the Upper Tennessee, Cumberland, and Green river basins and of the sister species C. taeniatus in the Cumberland, and Green river basins. Additional mitochondrial DNA sequences of C. iris and C. taeniatus were added to increase sample sizes and coverage of historical distribution. Mitochondrial DNA analysis demonstrated haplotype sharing between taxa, but with many unique haplotypes occurring in the upper Tennessee River basin. Nuclear DNA microsatellite loci revealed low levels of genetic diversity within populations of C. iris within the Upper Tennessee River basin, but high levels of divergence from C. iris and C. taeniatus of the Green and Cumberland River basins. The nuclear DNA analysis showed high admixture within and among sampled populations of C. iris throughout the Upper Tennessee River Basin with minimal geographic structuring among sub-basins. Further, phenotypic diversity was assessed using geometric morphometrics and decision tree and random forest analysis. Decision-tree and random forest analysis identified maximum height from the umbo to the ventral margin, periostracum color, shell width, and ray coverage to be defining characteristics for field identification of the focal taxa. Geometric morphometrics showed high overlap of shell shape for the focal taxa regardless of locality. While cryptic biodiversity was not detected in the Upper Tennessee River Basin, on a larger geographic level, cryptic biodiversity was detected using the combination of the mtDNA, nuclear DNA, and morphological data, which showed that C. taeniatus and C. iris from the Green River drainage were distinct from populations of C. iris in the upper Tennessee River basin. / Master of Science / Worldwide, freshwater mussel species diversity is greatest in North America; however, both abundance and diversity have declined in Canada, the United States, Mexico and the countries of Central America. Among rivers of North America, the Ohio River and its large tributaries, which include the Green, Cumberland, and Tennessee River drainages, have been noted for their high levels of biodiversity of freshwater mussels. Freshwater mussels contribute many services to freshwater ecosystems, including nutrient recycling and storage, structural habitat, substrate and food web modification. Dense populations of freshwater mussels have significant impacts on the surrounding ecosystem; however, due to their sedentary lifestyles, freshwater mussels are particularly susceptible to many biotic and abiotic stressors. Examples of stressors include agricultural runoff, temperature fluctuations, and dams which can alter stream conditions into more lake-like conditions and therefore affect the distributions of host fish populations. These stressors put mussels at risk for extirpation, which in turn, reduces the ecological biodiversity of these river drainages. Like other freshwater mussel species, the rainbow mussel (Cambarunio iris) of the Upper Tennessee River drainage, Mountain Creekshell (Leaunio vanuxemensis) of the Cumberland and Tennessee River drainages, and Kentucky Creekshell (Leaunio ortmanni) of the Green River drainage are in danger of decline due to anthropogenic changes in biotic and abiotic factors. Habitat degradation and loss have been of particular concern to managers. Life-history strategies for these three species are still widely unknown, and due to the overlap in their distributions, both phylogenetic and morphological analyses are needed to distinguish between species and populations to determine the best approach for management and conservation. The lack of understanding of taxonomic relationships in combination with morphologically similar characters poses a threat to conservation of these three species. The phylogenetic species concept is defined as an irreducible group whose members are descended from a common ancestor and who all possess a combination of certain defining, or derived traits, whereas the biological species concept is defined as groups or populations that are reproductively isolated from each other, meaning individuals from different groups cannot breed with one another. The results of my study have led to a better understanding of the phylogenetic relationships and species status of individuals collected from different localities of L. ortmanni and L. vanuxemensis and C. iris collected from the Green and Cumberland River drainages and the Upper Tennessee River drainage. In addition, morphological analyses were conducted to identify which traits are best for external identification of these three look-alike species, so they can be more reliably identified in the field.

Risk assessment of environmental exposure to chronic, trace concentrations of contaminants presents an analytical challenge to interpret data in a biologically meaningful way. Biomarkers are compounds that can provide integrated information concerning the effects of contaminants on biochemical processes. The metal-binding protein, metallothionein (MT), is a biomarker of toxic heavy metals, such as cadmium (Cd), since these metals bind to MT in vivo and induce transcription of MT genes with subsequent MT protein synthesis. A high performance liquid chromatography (HPLC)-thermospray microatomization-atomic absorption spectroscopy (AAS) method was developed for detecting Cd proteins from two invertebrate models; freshwater mussels (Pyganodon grandis) from a whole lake ecosystem exposure to Cd (Experimental Lakes Area, Canada), and zebra mussels (Dreissena polymorpha) recently introduced to North America. Methods for coupling gel filtration HPLC to AAS or inductively coupled-mass spectrometry (ICP-MS) were developed to provide sensitive and selective information on metal-binding proteins in freshwater mussel extracts. Sensitive metal detection by these methods necessitated precautions to minimize HPLC column-protein exchange of metals. These interactions were relevant to the determination of low concentrations of mussel MT-like proteins (MLPs) by these metal-specific detection systems. Saturation methods employing Cd as a metallic marker for the quantification of characterized MTs were adapted for freshwater mussels exposed to low environmental Cd concentrations. Characterization of Cd-saturated mussel extracts by HPLC-ICP-MS demonstrated the presence of copper and zinc, metals physiologically bound to MT, in the principal metal-binding fraction of mussel extracts. Experimental results also indicated that mussel MLPs are not as heat-stable as mammalian MT. Zebra mussels were chosen as a bioindicator species for obtaining a standard of freshwater MT biomarker for toxi

Conselho Nacional de Desenvolvimento Científico e Tecnológico / Rhipidodontini (Rhipidodonta Mörch, 1853 + Diplodon Spix in Wagner, 1827) é grupo de bivalves de água doce tem taxonomia complicada, devido às descrições originais sucintas e muitas vezes pouco ou não ilustradas, somado a isto, estes bivalves carecem de uma revisão detalhada. Estas lacunas de informação têm gerando uma grande flutuação nas espécies consideradas válidas pelos diferentes autores, dificultando a identificação das mesmas, assim como da biologia e distribuição. Assim, se propôs neste estudo a revisão taxonômica das espécies de Rhipidodontini nas bacias do alto rio Paraná, rio São Francisco e rios costeiros do Atlântico Leste, Norte e Nordeste. Para alcançar este objetivo vistoriamos material em coleções no Brasil e exterior. Coletas foram realizadas em diversas localidades para obtenção de exemplares para descrição das partes moles e gloquídios. As informações obtidas, somado ao descrito na literatura, foram utilizadas para traçar um panorama de distribuição e conservação das espécies. As principais características das conchas foram utilizadas para elaboração de uma chave dicotômica para auxílio na identificação. Uma análise morfométrica foi empregada com o intuito de distinguir as espécies através da forma da concha. Reconhecemos Diplodon e Rhipidodonta incluídos na tribo Rhipidodontini. Em Diplodon foram identificadas seis espécies nas bacias estudadas: Diplodon ellipticus Spix in Wagner, 1827; Diplodon fontainianus (dOrbigny, 1835); Diplodon jacksoni Marshall, 1928; Diplodon multistriatus (Lea, 1831); Diplodon paulista (Ihering, 1893) e Diplodon rhombeus Spix in Wagner, 1827. Apesar de Diplodon granosus (Bruguière, 1792) possuir extensos registros na região estuada, a espécie foi limitada a região amazônica na nossa avaliação. Em Rhipidodonta, foi reconhecida uma única espécie, Rhipidodonta garbei (Ihering, 1910). Entre estas espécies, temos algumas tradicionalmente reconhecidas como válidas (e.g. D. ellipticus e D. granosus), contudo, outras foram revalidadas (e.g. D. jacksoni e R. garbei) e redefinidas perante a análise do material tipo, partes moles e gloquídio. Não foi possível a eleição de uma única característica morfológica para a separação das espécies, porém detalhes das brânquias, estômago, contorno da concha e escultura umbonal figuraram entre as mais utilizadas. Para a separação dos gêneros de Rhipidodontini foram empregados atributos dos gloquídios (e.g. gancho gloquidial, protuberância e forma do gloquídio) e das brânquias (e.g. forma da brânquia e conexão entre as lamelas). A chave dicotômica com base em características das conchas auxiliou a separar as espécies de Rhipidodontini. A análise morfométrica constituiu uma ferramenta útil na separação das espécies, corroborando as identificações prévias. Salientamos que o estudo aqui apresentado deve ser expandido para outras bacias hidrográficas sul-americanas com o intuito de se conhecer a real diversidade destes bivalves de água doce / Rhipidodontini (Rhipidodonta Mörch, 1853 + Diplodon Spix in Wagner, 1827) is a tribe of freshwater bivalves with a complicated taxonomy, mainly due to the poor original descriptions, sometimes without illustrations, thereby a group needing a careful revision. The lack of information created a great variation in species considered valid by deferent authors, complicating the study of other aspects like distribution and biology. Therefore, were proposed in this study the taxonomic revision of Rhipidodontini in watersheds of Paraná River, São Francisco River and Coastal Atlantic rivers of East, North and Northeast. In order to achieve this goal museum collections were visited in Brazil and in other countries. Fields surveys were done in several localities to obtain fresh specimens to describe soft parts and glochidium. The information obtained added to information available in the literature were used to present and overview about distribution and conservation of the species. The main shell characteristics were employed to prepare an identification key to aid species differentiation. A morphometric analysis was used to distinguish species based on shell measurements. Diplodon and Rhipidodonta were recognized as valid genus included in tribe Rhipidodontini. Inside Diplodon were identified six species in the surveyed watersheds: Diplodon ellipticus Spix in Wagner, 1827; Diplodon fontainianus (dOrbigny, 1835); Diplodon jacksoni Marshall, 1928; Diplodon multistriatus (Lea, 1831); Diplodon paulista (Ihering, 1893) and Diplodon rhombeus Spix in Wagner, 1827. Despite Diplodon granosus (Bruguière, 1792) has extensive records in the studied region, this species was restricted to Amazonian region in our evaluation. In the genus Rhipidodonta were recognized only one species Rhipidodonta garbei (Ihering, 1910). Among these species, there are some traditionally accepted as valid (e.g. D. ellipticus e D. granosus), however other were revalidated and redefined based on analysis of type material, soft parts and glochidium (e.g. D. jacksoni e R. garbei). It was impossible to choose only one morphologic characteristic to discriminate the species, but details of gills, stomach, shell outline and umbonal sculpture were among the most important. The genera of Rhipidodontini were separate using attributes of glochidium (e.g. gloquidial hook, protuberance and shape of glochidium) and gills (e.g. gills shape and lamellar connections). The identification key based on shell characteristics helped to distinguish the species of Rhipidodontini. The morphometric analysis was considered a useful tool to separate the species, supporting the previous identification. The evaluation presented here should be expanded to other South American hydrographic catchments for determining the real diversity of these freshwater mussels

Conselho Nacional de Desenvolvimento Científico e Tecnológico / Rhipidodontini (Rhipidodonta Mörch, 1853 + Diplodon Spix in Wagner, 1827) é grupo de bivalves de água doce tem taxonomia complicada, devido às descrições originais sucintas e muitas vezes pouco ou não ilustradas, somado a isto, estes bivalves carecem de uma revisão detalhada. Estas lacunas de informação têm gerando uma grande flutuação nas espécies consideradas válidas pelos diferentes autores, dificultando a identificação das mesmas, assim como da biologia e distribuição. Assim, se propôs neste estudo a revisão taxonômica das espécies de Rhipidodontini nas bacias do alto rio Paraná, rio São Francisco e rios costeiros do Atlântico Leste, Norte e Nordeste. Para alcançar este objetivo vistoriamos material em coleções no Brasil e exterior. Coletas foram realizadas em diversas localidades para obtenção de exemplares para descrição das partes moles e gloquídios. As informações obtidas, somado ao descrito na literatura, foram utilizadas para traçar um panorama de distribuição e conservação das espécies. As principais características das conchas foram utilizadas para elaboração de uma chave dicotômica para auxílio na identificação. Uma análise morfométrica foi empregada com o intuito de distinguir as espécies através da forma da concha. Reconhecemos Diplodon e Rhipidodonta incluídos na tribo Rhipidodontini. Em Diplodon foram identificadas seis espécies nas bacias estudadas: Diplodon ellipticus Spix in Wagner, 1827; Diplodon fontainianus (dOrbigny, 1835); Diplodon jacksoni Marshall, 1928; Diplodon multistriatus (Lea, 1831); Diplodon paulista (Ihering, 1893) e Diplodon rhombeus Spix in Wagner, 1827. Apesar de Diplodon granosus (Bruguière, 1792) possuir extensos registros na região estuada, a espécie foi limitada a região amazônica na nossa avaliação. Em Rhipidodonta, foi reconhecida uma única espécie, Rhipidodonta garbei (Ihering, 1910). Entre estas espécies, temos algumas tradicionalmente reconhecidas como válidas (e.g. D. ellipticus e D. granosus), contudo, outras foram revalidadas (e.g. D. jacksoni e R. garbei) e redefinidas perante a análise do material tipo, partes moles e gloquídio. Não foi possível a eleição de uma única característica morfológica para a separação das espécies, porém detalhes das brânquias, estômago, contorno da concha e escultura umbonal figuraram entre as mais utilizadas. Para a separação dos gêneros de Rhipidodontini foram empregados atributos dos gloquídios (e.g. gancho gloquidial, protuberância e forma do gloquídio) e das brânquias (e.g. forma da brânquia e conexão entre as lamelas). A chave dicotômica com base em características das conchas auxiliou a separar as espécies de Rhipidodontini. A análise morfométrica constituiu uma ferramenta útil na separação das espécies, corroborando as identificações prévias. Salientamos que o estudo aqui apresentado deve ser expandido para outras bacias hidrográficas sul-americanas com o intuito de se conhecer a real diversidade destes bivalves de água doce / Rhipidodontini (Rhipidodonta Mörch, 1853 + Diplodon Spix in Wagner, 1827) is a tribe of freshwater bivalves with a complicated taxonomy, mainly due to the poor original descriptions, sometimes without illustrations, thereby a group needing a careful revision. The lack of information created a great variation in species considered valid by deferent authors, complicating the study of other aspects like distribution and biology. Therefore, were proposed in this study the taxonomic revision of Rhipidodontini in watersheds of Paraná River, São Francisco River and Coastal Atlantic rivers of East, North and Northeast. In order to achieve this goal museum collections were visited in Brazil and in other countries. Fields surveys were done in several localities to obtain fresh specimens to describe soft parts and glochidium. The information obtained added to information available in the literature were used to present and overview about distribution and conservation of the species. The main shell characteristics were employed to prepare an identification key to aid species differentiation. A morphometric analysis was used to distinguish species based on shell measurements. Diplodon and Rhipidodonta were recognized as valid genus included in tribe Rhipidodontini. Inside Diplodon were identified six species in the surveyed watersheds: Diplodon ellipticus Spix in Wagner, 1827; Diplodon fontainianus (dOrbigny, 1835); Diplodon jacksoni Marshall, 1928; Diplodon multistriatus (Lea, 1831); Diplodon paulista (Ihering, 1893) and Diplodon rhombeus Spix in Wagner, 1827. Despite Diplodon granosus (Bruguière, 1792) has extensive records in the studied region, this species was restricted to Amazonian region in our evaluation. In the genus Rhipidodonta were recognized only one species Rhipidodonta garbei (Ihering, 1910). Among these species, there are some traditionally accepted as valid (e.g. D. ellipticus e D. granosus), however other were revalidated and redefined based on analysis of type material, soft parts and glochidium (e.g. D. jacksoni e R. garbei). It was impossible to choose only one morphologic characteristic to discriminate the species, but details of gills, stomach, shell outline and umbonal sculpture were among the most important. The genera of Rhipidodontini were separate using attributes of glochidium (e.g. gloquidial hook, protuberance and shape of glochidium) and gills (e.g. gills shape and lamellar connections). The identification key based on shell characteristics helped to distinguish the species of Rhipidodontini. The morphometric analysis was considered a useful tool to separate the species, supporting the previous identification. The evaluation presented here should be expanded to other South American hydrographic catchments for determining the real diversity of these freshwater mussels

No description available.

Freshwater mussels are particularly susceptible to injury from exposure to hazardous substances due to their sessile nature and filter feeding biology. There have been various Natural Resource Damage Assessment and Restoration (NRDAR) cases in the United States involving injury to freshwater mussels due to releases of hazardous substances into rivers and streams. Restoration of mussels in these cases typically involves propagation of mussels at a hatchery facility and their subsequent stocking or release at restoration sites. However, determination of the services lost due to injury to mussel populations and the appropriate level of restoration (and associated costs) to recover those losses has varied among NRDAR cases. Standardized methods would facilitate injury determination and restoration planning for future cases involving injury to mussels. The purpose of this research was to use two of the earliest and largest NRDAR cases (Certus, Inc. and Lone Mountain Processing, Inc. (LMPI)) involving injury to mussels to: 1) determine whether restoration for these cases was sufficient and 2) analyze restoration efforts for application in future NRDAR cases (i.e., lessons learned and development of standardized methods). This study represents the first evaluation of mussel restoration efforts in a NRDAR context. In general, 4.8% to 6.1% of juvenile mussels that excysted from host fishes in the hatchery survived to be eventually released at restoration sites. Further, based on expected survival and recruitment rates of released mussels, monitoring of restoration sites found 43% to 15% of the expected number of mussels. Understanding reasons for this discrepancy between expected and estimated survival is critical for determining the level of restoration success. If released mussels are either establishing and/or recruiting outside of monitoring area but otherwise alive and breeding, then they should count towards successful restoration. In contrast, if released mussels have either high mortality over time or are dying shortly after release, then expected gains from these mussels should not count towards successful restoration. I developed a mussel-specific Resource Equivalency Analysis (REA) for use in future NRDAR cases that compares the loss of services, using Discounted Mussel Years (DMYs) as units, to the expected gain in services from restoration. Applying this analysis to the Certus and LMPI NRDAR cases suggests that mussel restoration was successful (i.e., expected DMYs gained are greater than those lost), even when it was assumed that 75% of released mussels were dying after being released at restoration sites. Finally, a cost analysis of two mussel propagation facilities found that the yearly cost per mussel released at a restoration site ranged from $4.36 to $96.48. The suite of species propagated each year varied. As some species are more difficult to propagate than others, the cost per mussel varied widely. These data will facilitate the determination of restoration costs in future cases. Together, this information provides a starting point for consistently estimating restoration effort and costs for future NRDAR cases involving freshwater mussels. / Doctor of Philosophy / Freshwater mussels provide numerous ecosystem services. Most importantly, they purify large volumes of water, and provide habitat and food for other animals. However, they are highly vulnerable to chemical spills because they cannot move long distances quickly and they are directly exposed to toxic substances if they filter water. There have been many cases in past decades where vulnerable mussel populations were exposed to chemical spills. When these populations are injured, the services they provide are lost until the population can be restored to pre-spill conditions. Restoration of mussel populations usually involves raising juvenile mussels in hatchery facilities and then releasing them in areas where populations were injured. Determining the appropriate level of restoration needed to restore populations has varied widely among cases. A standardized approach would facilitate determination of restoration and restoration costs. I used data from two cases (Certus, Inc. and Lone Mountain Processing, Inc.) where mussel populations were injured due to a chemical spill to: 1) determine whether restoration for these two cases was successful and 2) develop tools and draw insights for use in future cases where mussels are injured. This study represents the first evaluation of restoration success of freshwater mussels in a NRDAR context. On average, 4.8% to 6.1% of juvenile mussels produced at two Virginia hatchery facilities survived to be released at restoration sites. Further, of the mussels released, only 43% to 15% of the expected mussels were found in later years. These "missing" mussels are either leaving and/or breeding outside of their release areas, or they are dying and failing to provide important ecosystem services. Further study is needed to determine the degree to which each of these is the case. I also developed a mussel-specific method of determining how much restoration is needed to provide the amount of ecosystem services as pre-spill conditions (called Resource Equivalency Analysis or REA). Application of REA to these two test cases (Certus, Inc. and Lone Mountain Processing, Inc.), I showed that restoration for these cases was successful, even if as much as 75% of released mussels are dying after being released at restoration sites. Finally, I found that the cost of successfully releasing a mussel ranged from $4.36 to $96.48 per mussel. This information is useful for estimating the cost of restoration plans in future chemical spills that injure freshwater mussels.

The Big South Fork National River and Recreation Area (NRRA), located in Tennessee and Kentucky, has prepared a management plan to include restoration of its mussel fauna to historic levels. Restoration activities include propagation of juvenile mussels and relocation of adults to suitable sites in the Big South Fork of the Cumberland River (BSF) and its tributaries. This study was conducted to identify host fish for Cumberland elktoe (Alasmidonta atropurpurea) and Cumberland bean (Villosa trabalis), to determine suitable juvenile culture conditions for Epioblasma brevidens and V. trabalis, and to locate sites important to future mussel restoration efforts in the NRRA. Host fish identifications and propagation techniques were determined for two of the endangered species in the NRRA, Cumberland elktoe (Alasmidonta atropurpurea) and Cumberland bean (Villosa trabalis). Of seven host species tested, banded sculpin (Cottus carolinae) was the most suitable host fish for propagation of A. atropurpurea. Of five host species tested, fantail darters (Etheostoma flabellare) were the most suitable host fish for propagation of V. trabalis. Culture techniques to raise juvenile mussels in captivity were evaluated, using newly metamorphosed juveniles of V. trabalis and E. brevidens in recirculating systems. No differences in juvenile growth or survival were detected among substrates used (fine sediment, coarse sand, and a mixture of the two). Recirculating system design seemed to affect juvenile growth and survival; however, variable condition of juveniles also seemed to affect results, making it difficult to determine effects from trial treatments. Finally, an assessment of potential sites in the NRRA for restoration activities was conducted using spatial analysis in a geographic information system (GIS) and several measures of conservation value. Mussel restoration sites were assessed for potential threats from adjacent land uses that may negatively affect mussels, including coal mines, oil and gas wells, transportation corridors, agriculture and urban development. Sites were also evaluated on their current conservation value to designate which sites are most important to long-term maintenance of mussel fauna. Several sites were identified that contain relatively few land-use threats, and are appropriate for mussel restoration activities, including Big Island, Station Camp Creek, and Parchcorn Creek sites on the mainstem BSF, as well as sites on Clear Fork and North White Oak Creek. Many of these sites also have high conservation values. Other sites had relatively high land-use threats that need to be addressed before restoration activities take place. Such sites include Leatherwood Ford, Rough Shoals Branch, Blue Heron, and Yamacraw on the mainstem BSF. The dominant threat to most sites came from transportation corridors, whereas some sites in southern and eastern portions of the watershed also were threatened by coal mines, and oil and gas wells. / Master of Science

Thesis (M.S.)--University of Tennessee, Knoxville, 2010. / Title from title page screen (viewed on July 20, 2010). Thesis advisor: Paul Ayers. Vita. Includes bibliographical references.

Denna studie handlar om den vanliga sötvattensmusselarten Unio tumidus (U. tumidus), som har en viktig roll i vattenrening genom att filtrera organiskt material. Studien undersöker hur exponering för laboratorieförhållanden påverkar musslornas filtreringsförmåga genom att jämföra musslor som har anpassats till laboratorieförhållanden under olika tidsperioder. Experimentet undersökte effekterna av temperatur och laboratorieanpassningstid på U. tumidus. Fyra akvarier användes, två vid 5°C och två vid 15°C, och sex experimentkammare fanns i vardera akvarier. Musslorna som antingen hade hållits i laboratoriemiljö i ungefär ett år eller nyligen fångats vilda, anpassades till den nya temperaturen i cirka en dag innan experimentet startade och vattenprover togs vid tre olika tidpunkter för att mäta turbiditet och klorofyllkoncentration. En tvåfaktors ANOVA-analys användes för att mäta filtreringsförmågan. Resultaten visar att testtemperaturen var signifikant vid 3 och 46 timmar för turbiditet och vid 46 timmar för klorofyll, vilket tyder på att skillnaderna mellan testtemperaturen vid dessa tidpunkter troligen inte är slumpmässiga och att filtreringshastigheten var högre vid högre temperatur. Det fanns ingen signifikant skillnad mellan musselkälla (labb vs vilda) vid båda tidpunkterna för vare sig turbiditet eller klorofyll, vilket tyder på att det inte finns någon signifikant skillnad mellan laboratorieanpassade och vilda musslor. Vid 46 timmar var signifikansnivån för source*testtemperatur signifikant för klorofyll. Sammantaget tyder resultaten på att temperaturen kan påverka klorofyllnivåerna, där högre temperatur ger effektivare filtrering både för laboratorieanpassade och vilda musslor, med viss evidens för att laboratorieanpassning kan påverka klorofyllfiltrering vid låga temperaturer. Resultaten av denna studie är också relevanta för diskussionen om musslors ekosystemtjänster. Detta kan vara särskilt viktigt i ekosystem där vattnet är förorenat och där musslor kan hjälpa till att minska mängden föroreningar i vattnet. / This study is about the common freshwater mussel species Unio tumidus (U. tumidus), which plays an important role in water purification by filtering organic material. This study investigates how exposure to lab conditions affects the filtering ability of these mussels by comparing mussels acclimated to lab conditions over different time periods. The experiment examined the effects of temperature and lab acclimation time on U. tumidus. Four aquaria were used two at 5°C and two at 15°C and were performed with six experimental chambers each. The mussels which constituted a group held in the lab for approximately 1 year or recently wild caught, were acclimated to the new temperature for about 1 day before the experiment began, and water samples were taken at three different times to measure turbidity and chlorophyll concentration. A two-factor ANOVA analysis was used to measure filtration ability. The results show that the test temperature was significant at 3 and 46 hours for turbidity and at 46 hours for chlorophyll, indicating that the differences between test temperature at these times are likely not random and that filtration rates were higher at higher temperature. There was no significance between source (lab vs wild) at both times for both turbidity and chlorophyll, suggesting that there is no significant difference between laboratory-acclimated and wild mussels. At 46 hours the significance level for source*testtemperature was significant for chlorophyll. Overall, the results suggest that can affect chlorophyll levels with higher temperature providing more efficient filtration for both lab-acclimated and wild caught mussels, with some evidence that lab acclimation can affect performance of chlorophyll filtration at low temperatures. The result of this study is also relevant to the discussion of mussel ecosystem services. This may be particularly important in ecosystems where water is polluted and where mussels can help reduce the amount of pollutants in the water.