Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 31 for “"mussel populations"”.
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Development and validation of standardized sampling protocols for assessing freshwater mussel populations in Missouri
Freshwater mussels are among the most threatened aquatic fauna in North America. Given the need for continued monitoring of threatened mussel species, an evaluation of the effectiveness of metrics from visually-based sampling methods is an essential step in assessing populations. We surveyed 14 …
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Population trends and ecological community interactions of freshwater mussels
Freshwater mussels (order Unionida) are a globally widespread taxon which have been described as ecosystem engineers due to their capacity to modify freshwater habitats and facilitate other taxa, with effects on wider biodiversity. At the same time, freshwater mussels rank among the most threatened …
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Geochemical and Taphonomic Signatures of Freshwater Mussel Shells as Evidence of Mercury-Related Extirpations in the North Fork Holston River, Virginia
This study utilized freshwater mussel shells to assess the role of mercury contamination in the North Fork Holston River, an aquatic habitat affected by extensive extirpations of mussel populations starting in the early 1970's. Mussel shells (n=366) collected from 5 sites, upstream and downstream …
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Evaluation of the Effects of Mining Related Contaminants on Freshwater Mussels (Bivalvia: Unionidae) in the Powell River of Virginia and Tennessee
… Tennessee, USA and supports a diverse freshwater mussel assemblage of 29 extant species. Throughout the river major ion and trace element concentrations have increased over the last several decades due to extensive surface coal-mining in the headwaters in Virginia. As watershed area affected by …
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Assessment of Mussel Declines in the Clinch and North Fork Holston Rivers Using Histological Evaluations of Vital Organs
… contain some of the most diverse freshwater mussel assemblages in the United States; however, both rivers are experiencing declines in mussel populations. The first component of this study used histological evaluations and water quality data to determine whether mussels were negatively …
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Development of DNA markers and the genetic analysis of seven populations of the freshwater mussel Lampsilis radiata siliquoidea (Bivalvia: Unionidae) in north central Minnesota
… size on heterozygosity in seven different sized populations of the freshwater mussel Lampsilis radiata siliquoidea (Bivalvia: Unionidae) in north central Minnesota. Random amplified polymorphic DNA (RAPD), heteroduplex, and single-stranded conformational polymorphism (SSCP) analyses were …
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Post-settlement processes and early life history dynamics of zebra mussels (Dreissena polymorpha) in the Hudson River estuary
… the dynamics of demographically “open” aquatic populations. Even though we often have a good understanding of events and processes that occur to visible adult stages, particularly those of economically important species, in most cases we know very little or nothing about processes occurring to …
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Factors Influencing Mussel Abundances across Southwest USA Rivers: A Test of an Underlying Assumption of the More-Individuals Hypothesis
… general pattern of greater numbers of freshwater mussels (Unionidae; with similar feeding behaviors) along a large productivity gradient from west to east Texas. I compiled published and unpublished surveys from 2000 to 2024 across nine Texas river drainages, spanning 61 reaches and 744 mussel …
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Toxicity of zinc, copper, and sediments to early life stages of freshwater mussels in the Powell River, Virginia
The decline in mussel fauna of the Powell River has been attributed to extensive mining activities in headwater streams of Wise and Lee counties, Virginia. Surface mining causes erosion, sedimentation, and contamination of water with toxic substances from coal washing and waste piles. Historical …
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Large-scale forcing of coastal communities
… were observed where growth rates were lowest. Mussel size classes were found to have different growth rates, most probably due to differing factors such as predation, food availability, and reproduction. Predation and grazing effects differed between regions. Barnacle cover was shown to be …
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Influences of Historical and Contemporary Environmental Conditions on Threatened and Endemic Aquatic Organisms
… and population structure of fishes and mussels. The first chapter assesses genomic hybridization dynamics between the endemic and threatened Macrhybopsis australis and the widespread M. hyostoma in the Red River basin of Texas. This work found hybridization in a reach of the river …
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Characterizing the Microbiome of Scottish Freshwater Pearl Mussels (Margaritifera margaritifera): A Metabarcoding Analysis using Next-Generation Sequencing
Bivalves, such as the freshwater pearl mussel (Margaritifera margaritifera), are keystone species in freshwater habitats, functioning as ecosystem engineers, biological indicators, and flagship species. Despite their ecological significance, M. margaritifera populations are undergoing rapid …
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Abiotic and biotic factors influencing the decline of native unionid mussels in the Clinch River, Virginia
Declining unionid populations in the Clinch River are of concern due to the high endemism in the diverse fauna of the Cumberlandian region. Increase in agricultural and mining activities, as well as in industry and urbanization, are coupled with unionid declines throughout the watershed. In many …
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Pelagic dispersal and population connectivity of the green-lipped mussel (Perna canaliculus) in the Bay of Plenty
… the pelagic dispersal and connectivity in wild mussel populations is important for their sustainable management and for guiding the harvesting of wild seed for the mussel aquaculture industry. However, due to the complexity of the larval dispersal process, most studies have been unable to …
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The maintenance, evolution, and impacts of inducible morphological defenses in Mytilus edulis: Responses to multiple and invasive predators
… I have explored induced defenses in the marine mussel Mytilus edulis as they are affected by (a) shared evolutionary history with invasive crab predators, (b) specificity of responses to multiple predators (singly and combined) with different foraging strategies, and (c) spatial and temporal …
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Experiments to culture juvenile freshwater mussels in small tanks, floating containers and sediment beds
Freshwater mussel culture has become an attractive enterprise because of its application for restoring depleted freshwater mussel populations, for rearing adults to support shell and cultured pearl industries, and for environmental monitoring and assessment. This study focused on testing indoor and …
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River-Floodplain Connectivity and Sediment Transport Potential: Applications to Sediment Dynamics on Floodplains and Juvenile Freshwater Mussel Settling in Rivers
… sediment transport and deposition, and juvenile mussel settling in three river systems in the US. A two-dimensional hydrodynamic model was developed and simulated model results were coupled with field measurements to study river-floodplain systems of the East Fork White River in Indiana, South …
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Freshwater Mussels as Biofilters
Freshwater mussels (Bivalvia: Unionidae) are filter feeders, removing phytoplankton and other suspended particulate matter from the water. The removal of suspended matter from water is often considered desirable, in order to reduce algal blooms and in the treatment of drinking water. This thesis …
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An Ecotoxicological Evaluation of the North Fork Holston River below Saltville, Virginia and Identification of Potential Stressors to Freshwater Mussels (Bivalvia:Unionidae)
… Saltville, Virginia has nearly extirpated most mussel populations. Because natural recovery of these populations has not occurred, this research combined field and laboratory assessments to determine the extent of ecological impairment in the river. In situ 60-day Asian clam (Corbicula fluminea) …
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Evaluation of the Certus, Inc. and Lone Mountain Processing, Inc. Natural Resource Damage Assessment and Restoration Cases to Restore Mussels in the Clinch and Powell Rivers in Virginia and Tennessee
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 …
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