Browsing by Author "Ciparis, Serena"

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    Coal-mining intensity influences species and trait distributions of stream fishes in two Central Appalachian watersheds
    Martin, Zachary P.; Angermeier, Paul L.; Ciparis, Serena; Orth, Donald J. (2020-11-29)
    Documenting responses of biotic assemblages to coal-mining impacts is crucial to informing regulatory and reclamation actions. However, attributing biotic patterns to specific stressors is difficult given the dearth of preimpact studies and prevalence of confounding factors. Analysing species distributions and abundances, especially stratified by species traits, provides insights into how assemblage composition shifts occur. We evaluated stream habitats and fish assemblages along a mining intensity gradient in 83 headwater (2nd- and 3rd-order) streams of the upper Clinch and Powell river basins in Virginia. Our multivariate gradient (MINE.PC1) was based on percentages of watershed area covered by surface mine, underground mine and valley fill to represent spatial variance in mining intensity. MINE.PC1 was positively correlated with conductivity and percentage of substrate as cobble. Forty fish-assemblage metrics were analysed via boosted regression trees to assess assemblage responses to mining intensity, while accounting for environmental variation and spatial structure among sites. Conductivity and MINE.PC1 were strongly negatively related to occurrences of Fantail Darter (Etheostoma flabellare) and sculpin (Cottus) spp. Several taxonomic, trophic and reproductive metrics of assemblage composition responded strongly to mining intensity or its instream correlates. For example, coal mining favoured omnivore-herbivores, but inhibited invertivores, simple lithophils and nonsimple nonlithophils. We revealed distinct negative and positive responses to mining-related stressors, which suggest changes to macroinvertebrate prey availability and/or contaminant loads contribute to fish extirpations in coalfield streams. Future assessments of mining impacts on fish assemblages could be more instructive by including characterisations of physicochemical stressors and regionally calibrated biotic metrics with demonstrated sensitivity to mining.
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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
    Phipps, Andrew Thomas (Virginia Tech, 2019-06-10)
    The Powell River is located in southwestern Virginia and northeastern 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 mining has increased, mussel populations have declined, especially in Virginia where populations have been severely reduced or extirpated. The upper watershed now has been extensively mined for coal, causing widespread effects on water and sediment quality. To investigate how mining may be affecting mussel populations, I first conducted a laboratory bio-assay to assess the effects of elevated major ions and the trace element nickel (Ni) on growth and survival of juvenile mussels, including one common species (Villosa iris) and one endangered species (Epioblasma capsaeformis). No significant differences in overall survival between treatments and control were observed for either species over a 70 day test period. Total growth was not significantly different between treatments and control for either species. However, overall growth varied significantly (p=0.009) between species, with V. iris (2.49 mm) exhibiting greater growth compared to E. capsaeformis (1.97 mm). Results suggest that major ion chronic toxicity alone or in combination with Ni at or below my test concentration is not a likely source of toxicity to juvenile mussels in the Powell River. Secondly, I conducted a field study in the Powell River using two cohorts of juveniles of Villosa iris to assess the effects of trace elements and PAH contamination related to mining on mussel survival and growth. Specific conductance was elevated throughout the Powell River, where site means ranged from 450 to 900 µS/cm. While mortality was high at all eight sites it was not significantly different among these sites (p>0.28); however, growth of juvenile mussels was significantly higher (p<0.001) in the lower river in Tennessee. Regression analysis showed significant relationships (p<0.001) of river kilometer with temperature, specific conductance, and aqueous major ion concentrations. A principal component analysis (PC) was conducted on all trace element data. Growth of Cohort 1 on Day 106 was best explained by the PC dominated by aqueous major ion concentrations (p<0.0001, R2= 0.65) and growth of Cohort 2 on Day 106 was best explained by specific conductance (p<0.0001, R2= 0.68). Growth of Cohort 2 at Day 423 was best explained by tissue trace element concentration PC1 and PC2 (p<0.0001, R2= 0.73). This study suggests major ions and select trace elements (Ba, Ni, Fe, Se, and Sr) in the Powell River are negatively affecting the growth of freshwater mussels and that the source of these contaminants is primarily from mining in the headwaters.
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    Evaluation of the relationships between watershed-scale land use and contaminants in aquatic environments and the use of freshwater snails as indicators of impairment
    Ciparis, Serena (Virginia Tech, 2011-05-02)
    The use of manure from animal feeding operations (AFOs) as fertilizer on agricultural land may introduce contaminants to aquatic environments that can negatively affect the health of aquatic organisms. This study utilized a landscape-scale regression-based design to assess the effects of AFOs on contaminant concentrations and resident populations of a pleurocerid snail, Leptoxis carinata, in streams within the Shenandoah River watershed (Virginia, USA). Individual characteristics of L. carinata were also evaluated to provide further understanding of observed population characteristics. In streambed sediment and mollusk tissue, concentrations of the trace element arsenic, used as an additive in poultry feed, were not directly related to watershed densities of AFOs. In-stream concentrations of dissolved nutrients and estrogenic compounds, measured as estrogenic activity, were directly related to watershed densities of AFOs. Population sex ratios of L. carinata varied across study sites, from balanced to female-biased, but were not related to concentrations of estrogenic compounds. However, the spatial variation in population sex ratios, coupled with little variation in site-specific sex ratios across seasons and generations, suggest an influence of site-specific environmental conditions. Individual-level studies of L. carinata revealed that there is an eight month lag between hatching and gametogenesis which could allow disruption of sexual differentiation by environmental contaminants, but further study of the effects of specific contaminants on sexual differentiation in this species is needed. Population densities of L. carinata were related to in-stream nutrient concentrations and landscape sources of nutrients, including AFOs, but none of these factors were directly related to the infection prevalence of digenetic trematodes in L. carinata populations. Although trematode infection rates in L. carinata populations do not appear to be viable indicators of the influence of eutrophic conditions on disease incidence in aquatic organisms, the identification of five types of trematodes in L. carinata populations highlights the utility of this snail species for further investigation of transmission dynamics of trematode parasites in lotic systems.
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    Investigation into Smallmouth Bass Mortality in Virginia's Rivers
    Orth, Donald J.; Alexander, Kathleen A.; Ciparis, Serena; Frimpong, Emmanuel A.; Henley, William; Voshell, J. Reese (Virginia Department of Game and Inland Fisheries, 2009-10)
    Episodic fish mortality began within the Shenandoah basin in 2004 and has since spread to upper James River basin. The reasons for this are unknown although water-borne contaminants, stormwater runoff, levels of parasitism, and intersex are considered important factors in these outbreaks. Utilizing an integrated research approach, we identified the principal factors associated with the fish kills and used this information to begin to identify mitigation, monitoring, and management options for securing the health of these waterways and the fish communities that live there. Our study design for 2008 included four sites that have experienced chronic spring-time fish kills and three sites that have not experienced fish kills. We have collected data on spatial and temporal dynamics of fish kills and examined invertebrate host species for trematode parasites, fish health metrics and parasitism, and land use and contaminant loads in a broad-scale study design in order to identify important variables associated with outbreaks of spring-time fish mortality and potiential long-term monitoring approaches. We collected over 20 smallmouth bass at each of seven sites during pre-kill period and repeated this during typical kill periods. Our primary objective was to investigate the spatial and temporal dynamics of fish kills in relation to select contaminants, fish health metrics, fish parasitism, land use, and population characteristics of snails in order to identify important variables associated with outbreaks of fish mortality in the system and candidate monitoring approaches. Our specific aims were to: 1. Classify watersheds to design a stratified random sampling procedure for examining land use, effect of suspected contaminants including suspended solids, dissolved nutrients, benthic chlorophyll a, periphyton biomass, estrogenic activity, and other organic contaminants. 2. Assess the health of wild, free-living smallmouth bass populations in sample sites based upon physiological markers of stress, key chemical stressors, macroparasite prevalence, diversity and intensity of infection; gross and histological assessment of tissue and organ pathology including pathogenic bacterial infection. 3. Using the data collected in (2) develop a novel health assessment index (HAI) to allow assessment of fish health by watershed classification and other key variables.4. Measure snail population density, sex ratios, and measure trematode prevalence, diversity and intensity of infection. 5. Develop detailed maps of land use and stressor sources and statistically assess land use and stressor relationships to items (2)-(4) above. 6. Provide preliminary identification and ranking of primary variables associated with fish kills in the Shenandoah basin and rank watersheds by levels of risk.
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    Using an interdisciplinary approach to improve efficacy of agricultural conservation practices for protecting stream health
    Mouser, Joshua Braden (Virginia Tech, 2024-08-19)
    Protecting water quality, biota, and ecosystem services of streams (cumulatively referred to as stream health) while increasing food production is a major global challenge. One way to balance these often-competing interests is through the installation of agricultural conservation practices, such as excluding livestock from streams via fencing and adjusting grazing patterns. However, conservation practices often do not improve stream health as expected. Failure to achieve stream health outcomes may be due to biophysical (e.g., conservation practices are not appropriate for the landscape) or social reasons (e.g., agricultural producers are not willing to use conservation practices). Therefore, the goal of my dissertation research was to understand factors influencing effectiveness of conservation practices using an interdisciplinary approach that integrates ecological engineering, ecology, and social science. My research focuses on southwest Virginia, a karst region where cattle grazing is common. In the introduction, I developed a social-ecological framework that outlines how the natural and social sciences can be used to guide effective placement and implementation of conservation practices and explain why interdisciplinary approaches are often necessary due to social-ecological connections that influence efficacy (i.e., feedbacks, heterogeneity, time lags, and thresholds). In Chapter 1, I modeled pollutant transport to characterize watershed features that contribute disproportionate amounts of pollutants to streams. I found that water, and associated nitrate, is primarily entering streams through subsurface pathways, whereas sediment is entering the stream through streambank erosion. Therefore, a combination of conservation practices that stop nitrogen at its source (e.g., nutrient management plans) and stabilize streambanks (e.g., fenced riparian buffers) could be useful for protecting stream health. For Chapter 2, I sampled water quality, habitat, and macroinvertebrates from 31 streams within sub-watersheds that span a range of pollutant yields, conservation practice densities, and agricultural land use extent to understand the pathways through which conservation practices influence stream health. Agricultural land use increased total nitrogen and decreased macroinvertebrate diversity, but conservation practices stabilized nitrogen and improved bank stability. Despite such improvements, adverse effects on water quality and habitat still limited the biotic assemblage. Therefore, innovative conservation practices, higher densities of existing practices, or allowing more time for the effects of existing practices to improve water quality and habitat may be required to achieve stream health goals. For Chapter 3, I surveyed producers to understand if they continue to use their conservation practices after their cost-share contracts end (i.e., persistence) and factors that influence persistence. Persistence was most strongly related to producers' attitudes towards the conservation practice, producers' motivations, and practice durability. Therefore, persistence could be encouraged by using producers' motivations to focus messaging on ways conservation practices are achieving producers' goals and allocating more funding to practice maintenance. Overall, my interdisciplinary approach led to a greater understanding of pollutant dynamics, the pathways through which conservation practices influence stream health, and social constraints to persistence. This knowledge can inform what conservation practices may be most effective and strategies to keep appropriate practices on the landscape long enough to achieve stream health goals.