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Fyffe, Deanna LynneMethods to Monitor Lake Erie's Harmful Algal Blooms: A Fellowship with the Cooperative Institute for Great Lakes Research
Master of Environmental Science, Miami University, 2017, Environmental Sciences
To fulfill the professional experience requirement for a Master of Environmental Science degree at Miami University, I completed a fellowship with the Cooperative Institute for Great Lakes Research (CIGLR). My work involved investigating data trends of recent Lake Erie harmful algal blooms and potential monitoring methods. Data trends revealed monitoring stations closest to the mouth of the Maumee River had the highest average cyanobacteria concentrations. Bloom biomass distribution tended to favor the surface of the water column but was likely influenced by wind speed in 2016 and 2017. I also compared chlorophyll-a data from a CIGLR-owned bbe FluoroProbe to laboratory extraction data. The bbe FluoroProbe provided consistent results when used in the field and in the laboratory, but generally identified less chlorophyll-a than pigment extraction methods. Additionally, I performed field, laboratory, and analytical work to evaluate commercial in situ fluorometers. Due to proprietary reasons, the individual fluorometer data could not be presented in this report. I provided an example field deployment evaluation for the YSI EXO2 Multiparameter Sonde, a CIGLR-owned fluorometer that was used during the field tests for ancillary data. The EXO2 ultimately had low accuracy when compared to traditional laboratory methods, but both methods produced similar data trends.

Committee:

Suzanne Zazycki, JD (Advisor); Bartosz Grudzinski, PhD (Committee Member); Vanni Michael, PhD (Committee Member)

Subjects:

Aquatic Sciences; Environmental Health; Environmental Science; Environmental Studies; Freshwater Ecology; Microbiology; Water Resource Management

Keywords:

Lake Erie, Great Lakes, harmful algal bloom, HAB, water quality, in situ, fluorometer, cyanobacteria, biomass, microcystis, chlorophyll, phycocyanin, pigment, research, laboratory, EXO2, FluoroProbe, NOAA, GLERL, CIGLR, monitoring

Hartung, Erik WalterAging bioretention cells: Do they still function to improve water quality?
MS, Kent State University, College of Arts and Sciences / Department of Biological Sciences
Stormwater runoff from impervious surfaces transports a variety of pollutants to freshwaters via urban drainage pathways. Bioretention cells are a stormwater control measure being widely adopted with the goal of receiving, infiltrating and improving quality of stormwater before it enters surface waters. However, there are uncertainties about the spatial distribution and concentration of toxic metals that accumulate and concerns about changes in hydrologic function of aging bioretention cells. This study sought to address those concerns using a survey of 26 parking lot bioretention cells in the greater Cleveland area, ranging in age from <1 to 7 years of service. Bioretention cells were found to accumulate Cu, Pb and Zn in their media through time, but the distribution of these toxic metal pollutants was homogenous with respect to depth and distance from the stormwater flowpath. The concentration of metals in bioretention cell media were well below EPA soil contamination thresholds. Bioretention cells were found to have reduced hydraulic conductivity as they age, but bioretention cells less than eight years old still met EPA standards for hydrologic function. Therefore, regular maintenance of bioretention cells may be needed to remove sediment and improve hydrologic function, but no remediation would be needed for toxic metals. It is expected that bioretention cells function to capture, infiltrate and remove pollutants from stormwater runoff, leading to water quality improvement downstream. However, there is a lack of knowledge regarding active bioretention cells' ability to perform these functions over the long-term. This study aimed to elucidate the function of bioretention cells for removal of toxic metal pollutants (Cu, Pb and Zn) from runoff over 7 years of service time. This study also sought to address the effects road salt may have on bioretention's ability to filter or retain toxic metal pollutants from stormwater. Using leach columns constructed with media from 19 active bioretention cells ranging in age from <1 to seven years old, this study found that age is not a good predictor of bioretention cell functioning for metal removal. Bioretention cells were found to function well for removing low concentrations of metals from stormwater, but had reduced functioning for removal of high concentrations of metals. Bioretention cells' ability to remove metals from stormwater was found to be similar at different locations within the cells. Road salt was found to reduce the functioning of aged bioretention cells (7 years of service) for Pb and Zn removal from stormwater, but had no effect on functioning for Cu removal. Bioretention cells less than eight years in age were found to be able to reduce the concentration of metals in stormwater to concentrations below EPA thresholds for freshwater, but road salt may reduce bioretention's ability to reduce the concentration of Pb and Zn in stormwater.

Committee:

David Costello (Advisor)

Subjects:

Aquatic Sciences; Biogeochemistry; Biology; Ecology; Environmental Engineering; Environmental Management; Environmental Science; Environmental Studies; Freshwater Ecology; Hydrologic Sciences; Hydrology; Land Use Planning; Natural Resource Management; Water Resource Management

Richardson-Coy, RobinFeeding Selectivity of an Algivore (Tropheus brichardi) in Lake Tanganyika
Master of Science (MS), Wright State University, 2017, Biological Sciences
Algivorous fish remove attached algae (periphyton) from the benthos in near shore areas of lakes. Periphyton has a complex three-dimensional structure dominated by Bacillariophyta (diatoms), Chlorophyta (green algae), and Cyanophyta (cyanobacteria). These three phyla vary in nutritional quality with diatoms providing essential fatty acids that consumers need for growth and reproduction. Selection of specific phyla may be driven by nutritional quality or it may be a function accessibility due to both mouth morphology of the fish and location of the algae in the periphyton community. I investigated whether Tropheus brichardi, an algivorous cichlid of Lake Tanganyika, selectivity feeds on periphyton and how their herbivory affects the periphyton community composition. I found that T. brichardi slightly selects for diatoms although it is unclear if that selection is driven by nutritional quality or accessibility. This slight selection for diatoms did not appear to affect community composition of the periphyton.

Committee:

Yvonne Vadeboncoeur, Ph.D. (Advisor); James Amon, Ph.D. (Committee Member); Volker Bahn, Ph.D. (Committee Member); Rebecca Teed, Ph.D. (Committee Member)

Subjects:

Aquatic Sciences; Biology; Ecology

Keywords:

feeding selectivity; algae; algivore; Tropheus brichardi; algal community composition

Kleinas, Nicole LVariation in female mate preference for a male trait that provides information about growth rate in the swordtail Xiphophorus multilineatus
Bachelor of Science (BS), Ohio University, 2015, Biological Sciences
Sexual selection is comprised of intersexual mate choice and intrasexual competition. In order for female choice to be adaptive, the benefits of being choosey need to outweigh the costs. Females could benefit from preferences for male traits that relay information about male quality and/or that increase offspring fitness. Female preferences are affected by genotype, environment, or a combination of the two. In the study species, Xiphophorus multilineatus, males belong to one of four genetic size classes, and one of two genetic reproductive tactics. Between these alternative reproductive tactics, growth rate may be under disruptive selection. Since growth rate relates to fitness, it is possible that females assess a potential mate’s growth rate by evaluating variation in male vertical body bars. I identified two aspects of the vertical body bars that are correlated with male juvenile growth rate. In addition, I demonstrated that females from a population of exclusively sneaker males show a preference for the barring pattern that represents a slower growth rate, which supports the proposed tactical disruptive selection on growth rate. Females from the sneaker line were also choosier in their preferences, which could potentially indicate that the fitness advantage to growing slower as a sneaker male may be greater than the fitness advantage to growing faster as a courter male.

Committee:

Molly R. Morris (Advisor)

Subjects:

Animal Sciences; Aquatic Sciences; Behaviorial Sciences; Biology; Evolution and Development

Keywords:

sexual selection; female preference; growth rate; disruptive selection; vertical body bars; xiphophorus multilineatus; swordtail

Bodamer Scarbro, Betsy LThe Physiological and Behavioral Responses of Yellow Perch to Hypoxia
Doctor of Philosophy, University of Toledo, 2014, College of Natural Sciences and Mathematics
Yellow Perch within Lake Erie's Central Basin must contend with the development of hypolimnetic hypoxia, which generally occurs August - October and reaches thicknesses of up to 8 meters off the lake bottom. Since Yellow Perch are primarily demersal benthivores, large portions of their primary habitat becomes unsuitable during hypoxic events. Field studies have shown that while Yellow Perch largely avoid hypoxia, they continue to forage for benthic prey despite hypoxic conditions. Little is known about the fine-scale behavioral changes of Yellow Perch during hypoxia, or the physiological consequences of hypoxic foraging. In controlled laboratory experiments, I analyzed the behavioral changes of Yellow Perch under simulated hypolimnetic hypoxia, and determined the physiological response of Yellow Perch to hypoxic exposure by measuring the response of a hypoxia-responsive protein, Hypoxic Inducible Factor-1-alpha (HIF-1a). Yellow Perch were subjected to normoxic (~8 mg DO/L), moderate hypoxic (~4 mg DO/L) or severe hypoxic (~2 mg DO/L) dissolved oxygen concentrations for durations of up to 8 hours, followed by a 40-hour normoxic recovery period. Baseline HIF-1a levels were detected in Yellow Perch liver tissues under normoxic conditions, and increased significantly after two hours of hypoxic exposure. HIF-1a peaked at 2 and 4 hours of hypoxic exposure under severe and moderate hypoxic conditions, respectively, but returned to levels similar to normoxic treatments by 8 hours of exposure. These results suggest Yellow Perch are well adapted to hypoxic conditions and that a direct negative feedback mechanism may aide survival under prolonged hypoxia. In order to observe the behavioral changes of Yellow Perch in stratified hypoxic conditions, I designed and constructed two experimental tank systems that simulated hypoxic conditions characteristic of temperate freshwater lakes. Using these systems, two behavioral experiments were conducted examining changes in behavior and consumption of Yellow Perch subjected to various thicknesses of hypolimnetic hypoxia. While the number of hypolimnetic forays did not differ between hypoxic and normoxic treatments, dive duration decreased significantly during hypoxia, resulting in less time total time in the hypolimnion. Consumption did not significantly decrease until hypoxic thickness reached 4.0 meters. These findings suggest that the ability of Yellow Perch to forage benthically is not greatly affected by hypoxia less than 2.6 meters in thickness; however, increasing hypoxic thickness likely decreases the energetic gain of benthic foraging, driving horizontal shifts in Yellow Perch populations to areas where hypoxia is thinner (< 2.6 m). Increases in the duration or spatial extent of hypoxia resulting from forecasted global climate conditions are likely to lead to further changes in community distributions, increased competition, and altered trophic interactions.

Committee:

Thomas Bridgeman, Ph.D. (Advisor); Christine Mayer, Ph.D. (Committee Member); W. Von Sigler, Ph.D. (Committee Member); Randall Ruch, Ph.D. (Committee Member); Jessica Head, Ph.D. (Committee Member)

Subjects:

Aquatic Sciences; Behavioral Sciences; Biology; Experiments; Freshwater Ecology; Limnology; Molecular Biology; Physiology

Keywords:

hypoxia; yellow perch, perca flavescens; stratification, Hypoxia Inducible Factor - HIF; fish behavior; Lake Erie

Given, EmmaLeigh KalebEvaluating Long-term Effects of Destructive Flooding on In-stream Riparian Characteristics and Macroinvertebrate Abundance in Low Order Headwater Streams
Master of Science in Biological Sciences, Youngstown State University, 2014, Department of Biological Sciences
In August of 2009 a flashflood scoured an assemblage of fourteen 1st -- 3rd- order headwater streams surrounding Zoar Valley Canyon in western New York State USA. Macroinvertebrate composition, watershed variables, and habitat features of these streams were quantitated in 2006 and reported in the peer-reviewed literature. The objective of this study was to determine long-term disturbance effects within these impacted streams, particularly as relation to meta-community assembly. Biotic and environmental assessments from 2011, 2012, and 2013 mirrored those from 2006, with biota collected from riffle/cobble segments by Surber net, and environmental/habitat variables quantified by a widely used Qualitative Habitat Evaluation Index (QHEI) that assesses in-stream and riparian characteristics. In- stream environmental variables such as substrate diversity and in-stream cover initially declined in quality and converged leading to homogenization of stream patches. Dissimilarity among stream communities for both biotic and environmental characteristic from year to year (assessed by Non-metric Multidimensional Scaling ordination) revealed that streams were differentially impacted and also suggested changes in meta-community composition in response to the disturbance. In 2006, partial correlations suggested a niche-based species sorting of organisms, whereas by 2011, this structuring was lost, suggesting a switch to either equivalence based neutral theory or homogenous patch dynamics. By 2013, although QHEI numbers were reaching pre-flood values, an environmental/biotic partial correlation (as seen in 2006) had yet to re-emerge, suggesting that macroinvertebrate communities were still facing the effects of this disturbance.

Committee:

Thomas Diggins, PhD (Advisor); Ian Renne, PhD (Committee Member); Carl Johnston, PhD (Committee Member)

Subjects:

Aquatic Sciences; Biology; Ecology; Environmental Science; Environmental Studies

Keywords:

macroinvertebrates; flooding; stream; disturbance; recovery

Phillips, Taylor K.Seasonal Movements of the Sandstone Falls Population of Walleye in the Lower New River
Master of Science (MS), Ohio University, 2014, Biological Sciences (Arts and Sciences)
Walleye in the lower New River have been intensively managed to protect the genetic integrity of the native Eastern Highlands strain of walleye, but little is known about the movement, habitat use and home ranges of these fish, especially post-spawn. Twenty walleye were implanted with internal acoustic transmitters. Tagged fish were monitored using both passive receivers and active tracking equipment. The objectives of this study were to (1) determine movement patterns of tagged fish pre- and post-spawn, (2) determine habitat use and whether walleye are selective when choosing habitat types, and (3) estimate the home ranges of tagged fish. Sixteen walleye were identified as pure Eastern Highlands fish, while four were identified as Lake Erie strain. Walleye spawn at Sandstone Falls and then travelled downstream where they were found in deep pools until the next spawning season when they returned to Sandstone Falls. Results supported previous studies on habitat preference as tagged walleye were selective in habitat use and preferred boulder/cobble substrate. Home ranges were typically located in the deep pools along the study area. The mean home range size, calculated using both passive and active tracking data, was approximately 90 km2(N=19) and did not differ significantly between males and females. Walleye preferred deep, slower streamflow pools. Mean depth occupied by tagged walleye was 3.4 meters (m) and there was a significant difference between walleye location and random location depth. There was no significant difference in occupied depth between seasons.

Committee:

Matthew White (Advisor); Molly Morris (Committee Member); Shawn Kuchta (Committee Member)

Subjects:

Aquatic Sciences; Biology; Wildlife Management

Keywords:

walleye telemetry; seasonal movement

Farmer, Troy MClimate Change Effects on Lake Erie Yellow Perch Reproduction and Recruitment
Doctor of Philosophy, The Ohio State University, 2013, Evolution, Ecology and Organismal Biology
Climate warming is expected to positively affect cool-water, temperate fish populations by lengthening the growing season and expanding thermal habitats suitable for positive growth. Yet, little is known about how a corresponding shortened winter might affect temperate fish populations, especially for species that require a prolonged period of cold temperature during the winter prior to spawning for proper ovary development. Additionally, events such as hypolimnetic hypoxia (O2 < 2 mg/L), are expected to increase with continue warming. We hypothesized that climate change would negatively affect temperate fish populations by 1) increasing bottom hypoxia during summer, which can reduce energy reserves (fish condition) prior to winter, when ovaries develop for many species, and 2) increasing winter water temperature, which could increase basal metabolic rates during winter (i.e., reduce energy available for ovary development) and disrupt thermal requirements necessary for proper ovary development. To test these hypotheses, we investigated the effects of winter temperature and female condition on Lake Erie yellow perch Perca flavescens reproductive development, egg and larval quality, and ultimately, fall juvenile abundance (a strong predictor of future recruitment to the yellow perch fishery in Lake Erie). Towards this end, we conducted laboratory experiments, a multi-year field study, and historical analyses. In our laboratory experiments, female yellow perch exposed to a long winter produced higher quality eggs (i.e., in terms of size, energetic, and lipid content) that both hatched at higher rates and produced larger larvae than lower quality eggs from females exposed to a short winter (Chapters 2 and 3). Counter to our hypotheses, reduced female condition entering winter did not adversely affect reproductive success (Chapter 3). Additionally, field and laboratory studies found that when spring warming happened extremely early, yellow perch spawning did not fully adjust, increasing the possibility of a mis-match between first-feeding larvae and their zooplankton prey (Chapter 2). Finally, we show through historical analyses that the negative effect of warm winters on Lake Erie yellow perch juvenile abundance appears to be consistent over 42 years (i.e., 1969-2010), and has persisted throughout a large-scale, nutrient-driven regime shift and restructuring of the food-web due to numerous introductions of invasive species (Chapter 4). Our research offers a previously unrecognized mechanism by which climate change can threaten temperate fish populations, through reductions in reproductive success. Our results also may have relevance to fisheries managers seeking to better anticipate the responses of fish populations to climate change. Specifically, given that our study has identified mechanisms that appear to be responsible for long-term population dynamics, our findings may allow for managers to monitor the appropriate variables (i.e., winter thermal regime) necessary to predict annual recruitment to the fishery for Lake Erie yellow perch. Additionally, because our study species has similar life-history and physiological requirements not unlike many other cool-water, temperate fishes, our findings may have relevance to fish populations in many ecosystems.

Committee:

Stuart Ludsin, Dr. (Advisor); Elizabeth Marschall, Dr. (Advisor); Konrad Dabrowski, Dr. (Committee Member); Maria Miriti, Dr. (Committee Member)

Subjects:

Aquatic Sciences; Biology; Ecology; Fish Production; Freshwater Ecology; Limnology; Zoology

Sullivan, Rachel KuhaneckVegetation on Riprapped Shorelines: Implications for Invertebrate Communities and Restoration of Nearshore Areas
Master of Science, University of Toledo, 2013, Biology (Ecology)
Coastal areas are increasingly habited by humans because of their attractiveness for recreation, aesthetics, and industrial purposes. Artificial structures, such as riprap, are used to prevent erosion but also have been shown to reduce biodiversity. The goal of my study was to examine the relationship between riprap altered shorelines, sediment composition, organic matter and invertebrate communities in areas that had shoreline vegetation and those that had not. Using broad taxonomic groups, we found that overall invertebrate diversity was 30% greater in areas adjacent to shorelines with added vegetation. The most abundant taxon, the oligochaetes, showed opposite trends with abundance increasing at least 50% at non-vegetated sites. The relationship between sediment composition and shoreline type was found to be the most significant driver of invertebrate community changes, with the ratio of silt to sand being seven times greater in the absence of vegetation, and diversity having a positive response to this increase. In the western basin of Lake Erie, where most shorelines have riprap alterations, adding vegetation should be considered as a useful management technique.

Committee:

Christine Mayer, Dr. (Advisor); Thomas Bridgeman, Dr. (Advisor); Jonathan Bossenbroek, Dr. (Committee Member); Kenneth Krieger, Dr. (Committee Member)

Subjects:

Aquatic Sciences; Ecology; Environmental Science; Limnology

Keywords:

Lake Erie; Invertebrate; Nearshore; Riprap; Vegetation; Diversity

Davidson-Bennett, Keely MarieWatershed Urbanization Impacts to Headwater Streams in Northeastern Ohio
Master of Science, The Ohio State University, 2011, Environmental Science

Watershed urbanization has been associated with declines in biodiversity and decreases in the proportion of pollution intolerant organisms. Some of these changes in community composition may be due to increased stormwater runoff from urbanized watersheds. In order to better understand how streamflow patterns change along a putative stormwater impact gradient and which abiotic factors may be driving shifts in macroinvertebrate community composition, we studied the hydrology, chemistry, and biology in six small streams in the Rocky River Watershed, northeastern Ohio. According to Ohio EPA classification, three of these streams were primary headwater streams, draining 0.41 to 1.22 km2; three headwater streams drained 3.47 to 7.25 km2. We measured flow at each stream using an Isco 2150 area-velocity flow meter from January 17 to December 9, 2010. We sampled each stream for macroinvertebrates and water and sediment chemistry three times: June 21 - 26, August 9 - 11, and September 30 - October 10, 2010.

Stream flashiness increased with watershed urbanization. The seasonality of high flow events was also altered in the more urbanized streams relative to the least urbanized streams, with least urbanized streams having the highest and urban streams having the smallest percentage of high flow days in the winter. The most urban primary headwater stream had larger average event peak flows than the least urbanized primary headwater stream during the growing season, but not the dormant season. Peak flows did not differ among the larger headwater streams. Macroinvertebrate biodiversity, as measured by the Shannon Index, declined along the urbanization gradient. Chemical, hydrologic, and physical habitat variables were significantly correlated with macroinvertebrate community characteristics; however, the variable most strongly correlated with each macroinvertebrate community metric was a hydrologic variable. Potential multiple linear regression models to describe aspects of macroinvertebrate community composition were created from combinations of abiotic factors. The five models with the lowest Schwarz Bayesian Information Criterion and Mallow’s Cp statistics for each macroinvertebrate metric were examined further, and those that met the model assumptions were retained. In one multiple regression model, skewness of streamflow and total phosphorous concentration in stream water were highly predictive of Shannon’s Index, while in the another regression model skewness of streamflow, flow during sampling, and days since the ninety-fifth percentile of streamflow was exceeded were significant predictors of Shannon’s Index. The relative abundance of intolerant macroinvertebrate taxa was best described by skewness of streamflow. The increased flashiness of urban streams relative to least urbanized streams, the larger average flood peaks of urban primary headwater streams in the growing season, and the shifts in seasonality of high flow events provide evidence of hydrologic impairment of the more urban streams in this study. This hydrologic impairment appears to be one of the mechanisms by which urbanization influences stream macroinvertebrate communities. Therefore, increased use of low impact design and more rigorous stormwater detention technologies within the watersheds may be needed to restore these streams.

Committee:

Charles Goebel, PhD (Advisor); Mazeika Sullivan, PhD (Committee Member); Richard Moore, PhD (Committee Member)

Subjects:

Aquatic Sciences; Ecology; Environmental Science; Hydrology

Keywords:

hydrology; stream; headwater; macroinvertebrate; urban

Amey, Katherine SpringerHydrology And Predictive Model Of Headwater Streams And The Groundwater/Surface Water Interactions Supporting Brook Trout Habitat In Northeast Ohio
PHD, Kent State University, 2011, College of Arts and Sciences / Department of Geology

The hydrology and hydrogeology of a set of eight cold-water streams in Lake and Geauga Counties in northeast Ohio were evaluated in order to develop a new predictive model for the successful introduction of native Ohio brook trout (Salvelinus fontinalis). The model may be used to assess future sites for potential introduction of this threatened species. A field study was conducted from February 2009 to May 2010 in streams where the brook trout had been previously introduced. These streams were good candidates for study because four had been designated successful, two variable, and two failed in terms of the brook trout’s ability to flourish by the Ohio Department of Natural Resources (ODNR). The field study examined the groundwater/surface water interaction in the hyporheic zones, ecologically important areas where brook trout build their spawning beds, known as redds. To improve on the current model of brook trout introduction, and subsequent habitat suitability index (HSI), this study determines if there is a relationship between the temporal and spatial variability of groundwater input into the stream’s hyporheic zone, and successful, variable or non-successful outcome of brook trout introduction. Nested minipiezometers at the riffle head and tail allowed the study of the water quality, hydrogeology, stable isotopes (δ18O, δD), soils, and ultimately determined the source of coldwater input to the streams. Benthic macroinvertebrates and ostracodes were analyzed to assess the biological integrity of the stream.

Factors found to be significant in successful Ohio trout populations were hydrology of the streams, including low discharge (Q<0.13-0.51 ft3/s), and hydrogeology of the aquifer, most importantly, a high hydraulic conductivity of the headwaters (K>100 gpd/ft2). Key features of successful streams include high percent canopy cover (40%-55%) or high percent instream cover (18%-37%), and a high number of benthic macroinvertebrate cold-water taxa (10-16 species). A long-term water temperature study over both winter and summer seasons (successful stream yearly average hyporheic water temperature 4.6°C-17.2°C and surface water temperature 0.3°C-18.0°C) is recommended prior to introduction. Successful streams are part of an ecologically sensitive “surface system”, and should be protected in the headwaters of streams sustaining the brook trout population.

Committee:

Alison Smith (Advisor); Mandy Munro-Stasiuk (Committee Member); Donald Palmer (Committee Member); Daniel Holm (Committee Member); Ferenc de Szalay (Committee Member)

Subjects:

Aquatic Sciences; Ecology; Environmental Geology; Freshwater Ecology; Geology; Hydrologic Sciences; Hydrology

Keywords:

Hydrology; Hydrogeology; Groundwater Surface Water Interaction; Vertical Hydrauic Gradient; Precipitation; Temperature Study;Brook Trout; Cold Water Streams; Stable Isotopes; Benthic Macroinvertebrates; Northeast Ohio; Predictive Model

Gray, Jonathon B.Reference Diatom Assemblage Response to Transplantation into a Stream Receiving Treatment for Acid Mine Drainage in Southeastern Ohio
Master of Science (MS), Ohio University, 2011, Environmental Studies (Arts and Sciences)
Acid mine drainage (AMD) is a prevalent legacy of coal mining within Appalachia. Streams receiving AMD effluent are drastically altered both chemically and biologically. Hewett Fork, a stream in southeastern Ohio, is one such affected stream. Although treatment methods have reduced acidity considerably downstream, the ability of Hewett Fork to sustain a biological community compared to those found in reference conditions remains unclear. To assess this, tiles colonized with diatom assemblages from an unimpacted stream were transplanted into Hewett Fork along a stream health gradient, from poor to good, and sampled after one, three, and six weeks in the treated stream. Chlorophyll a concentrations and species diversity metrics were calculated to compare reference assemblages to transplanted assemblages. Results suggested that after an initial one week acclimation period, assemblages at the uppermost and lowermost sites along the reach were relatively similar to those found in reference conditions, while sites within the middle region continued to show signs of impairment, although the factor(s) causing this impairment remain unknown. These findings suggest that although treatment has been effective on a site-specific basis, the expected linear-response to treatment may not be achieved due to underlying factors that are inhibiting reference-like biological communities from reestablishing within the affected stream reach.

Committee:

Morgan Vis, PhD (Advisor); Kelly Johnson, PhD (Committee Member); Brian McCarthy, PhD (Committee Member)

Subjects:

Aquatic Sciences; Biology; Conservation; Ecology; Environmental Science; Environmental Studies; Freshwater Ecology; Natural Resource Management; Water Resource Management

Keywords:

diatom; acid mine drainage (AMD); transplantation; stream; recovery; sacrifice zone; ecosystem structure

DuFour, Mark RHydroacoustic Quantifi cation of Lake Erie Walleye (Sander vitreus) Distribution and Abundance
Doctor of Philosophy, University of Toledo, 2017, Biology (Ecology)
This work was motivated to improve understanding of Lake Erie walleye (Sander vitreus) distribution and abundance. Lake Erie walleye are large migratory fish that are ecologically and economically important within the Great Lakes region. The population is monitored partly through a fishery independent gill net survey carried out by the Ohio Department of Natural Resources - Division of Wildlife (ODNR-DOW). However, high variation in annual CPUE has interfered with this survey's ability to identify changes in walleye abundance. Therefore, the ODNR-DOW was interested in the potential of coupling hydroacoustic sampling with the existing gill net survey to quantify Lake Erie walleye distribution and abundance. In this dissertation I address four major questions that helped optimally couple hydroacoustic and gill net surveys. In Chapter 1, I evaluated the impact of beam compensation on surveyed target strength (TS) data. I found that using an intermediate beam compensation (18 dB), greater than conventionally suggested (6 dB), provided a higher quantity of TS data with minimal impact on TS data quality. Increased beam compensation led to higher encounter rates and more TS data per fish, which ultimately provided a better characterization of the low density walleye population. In Chapter 2, I evaluated the influence of vessel size and day-night period on the availability of the walleye population to a hydroacoustic survey. I found that walleye were less likely to avoid smaller sampling vessels, but the vessel size effect decreased with depth. Also, during the fall period of the gill net survey, walleye were more available to hydroacoustic sampling at night. Finally, although vessel size and day-night sampling period are important logistical consideration, capturing spatial distributions across the survey should be prioritized in future surveys. In Chapter 3, I compared gill net catch-per-unit-effort (CPUE) and hydroacoustic abundance estimates from across a large survey area with varied environmental conditions. I found that the relationship between gill net CPUE and abundance changed across the survey along environmental gradients. This indicated that sub-optimal catchability and gear efficiency in the gill net survey limits its ability to quantify changes in abundance, and adding a hydroacoustic component to this survey would be beneficial. In Chapter 4, I developed a method to infer species composition of the hydroacoustic data while addressing many apportionment challenges, such as: limited and variable species composition data, subjective threshold decisions, and uncertainty in mean TS estimates. This method improved species composition estimates, propagated uncertainty from both sampling methods, and eliminated subjective threshold decisions. Distribution estimates corresponded with known patterns of walleye movements and ecology, while survey-wide estimates were comparable to independent estimates based on annual stock assessments. Using the methods outlined here in, hydroacoustics could be successfully coupled with the existing ODNR-DOW gill net survey to improve quantification of Lake Erie walleye distribution and abundance.

Committee:

Christine Mayer, PhD (Committee Co-Chair); Song Qian, PhD (Committee Co-Chair); Jonathan Bossenbroek, PhD (Committee Member); Patrick Kocovsky, PhD (Committee Member); David Warner, PhD (Committee Member)

Subjects:

Aquatic Sciences; Biology; Biostatistics; Ecology; Environmental Science; Freshwater Ecology; Natural Resource Management

Keywords:

Lake Erie, walleye, Sander vitreus, gill net, survey, hydroacoustic, target strength, beam compensation, avoidance, behavior, availability, catchability, efficiency, apportionment, species composition, threshold, uncertainty, Bayesian, hierarchical, model

Evans, Joshua R.Transcriptional Regulation of Select Light-Harvesting Genes during Photoacclimation in Lympha mucosa gen. et sp. prov. (Batrachospermales, Rhodophyta)
Master of Science (MS), Ohio University, 2017, Plant Biology (Arts and Sciences)
The strictly freshwater red algal order Batrachospermales has undergone numerous taxonomic rearrangements in the recent past to rectify the paraphyly of its largest genus Batrachospermum. These systematic investigations have led to the description of new genera and species as well as re-circumscription of some taxa. Specimens collected from two locations in southeastern USA were initially identified as being allied to Batrachospermum sensu lato, but could not be assigned to any previously described species. Comparison of DNA sequence data for two gene regions and morphology with other batrachospermalean taxa resulted in the proposal of a new monospecific genus Lympha mucosa gen. et sp. prov. to accommodate these specimens. A phylogeny of L. mucosa showed it is sister to the genus Volatus, but has morphological similarities with Batrachospermum sections Turfosa and Virescentia. This new taxon adds to the freshwater red algal diversity of southeastern USA, a region already known for biodiversity and high endemism of the aquatic flora and fauna. Lympha mucosa occurs in open and shaded sites of temperate streams and is abundant during summer months. Although most freshwater red algal taxa are considered shade-adapted, many species exhibit differences in photosynthetic rates and characteristics that indicate they have a much greater ability to acclimate to higher irradiances. Specimens of L. mucosa were collected from open (sun-acclimated) or shaded (shade-acclimated) sites and were exposed to low (<20 µmol photon m-2 s-1) or high (220 µmol photon m-2 s-1) for 72h in controlled conditions to examine photoacclimation. To observe regulation for this process at the transcriptional level, the L. mucosa plastid genome was assembled to provide sequence data for photosynthetic genes involved with light harvesting machinery. Of the six light-harvesting genes selected, two involved with photosystem I and one involved with phycoerythrin synthesis were downregulated at high light. This is the first evidence of transcriptional regulation as a potential mechanism for acclimation to varying irradiances in a freshwater red alga.

Committee:

Morgan Vis (Advisor); Sarah Wyatt (Committee Member); Harvey Ballard (Committee Member)

Subjects:

Aquatic Sciences; Bioinformatics; Biology; Biostatistics; Ecology; Evolution and Development; Experiments; Freshwater Ecology; Genetics; Molecular Biology; Organismal Biology; Plant Biology; Plant Sciences; Systematic

Keywords:

photoacclimation; red algae; gene expression; aquatic biology; phylogeny; photosynthesis

Justus, SavannahRELATIONSHIP BETWEEN LAND USE, HABITAT, AND AQUATIC BENTHIC INVERTEBRATE COMMUNITIES IN TROPICAL MONTANE FORESTS
BS, Kent State University, 2017, College of Arts and Sciences / Department of Biological Sciences
Research shows that changes in surrounding land use may have negative impacts on freshwater benthic systems through changes in surrounding physical habitat, increased nutrient inputs, or non-point pollution (Neumann & Dudgeon 2002). Riparian zone condition can alter erosion and sediment input, temperature, and food availability. Benthic macroinvertebrates play a key role in ecosystem processing in freshwater systems and are indicators of environmental stress. Although the effects of agricultural land use has been studied in temperate regions, little research has been done in Costa Rica, where high deforestation rates are threatening tropical montane forests (Foster 2001). This study compares invertebrate communities between protected forested streams and streams surrounded by agricultural land to understand how macrohabitat and microhabitat features affect richness, diversity, and community composition. Forested streams had significantly higher richness, diversity, habitat indicator scores, and QHEI scores. Channel morphology and riparian zone condition scores were significantly higher in forested streams. Riffles had more similar communities than pools based on Bray- Curtis dissimilarity. Overall, agricultural streams are a less suitable habitat for benthic macroinvertebrates but it is still unclear if microhabitat or macrohabitat differences have a stronger effect on community structure. This study reflects the importance of understanding how natural variation compares to large-scale land use. As agricultural expansion continues, we must understand how this will affect stream systems so we are able to mitigate any negative effects.

Committee:

Oscar Rocha, PhD (Advisor); Emmaleigh Given, MS (Other); Alison Smith, PhD (Committee Chair); Linda Spurlock, PhD (Committee Member); Ferenc de Szelay, PhD (Committee Member)

Subjects:

Aquatic Sciences; Biology; Ecology

Keywords:

macroinvertebrates, water quality, land use, agricultural expansion, tropical montane, Costa Rica, benthos

Shaw, Caitlin H. A Preliminary Investigation of Treating Metal Pollutants in Water by Slow-Release Hydrogen Peroxide
Master of Science (MS), Ohio University, 2017, Geological Sciences (Arts and Sciences)
Urban runoff can come into contact with a range of pollutants. Metal pollutants can pose an especially significant threat to water quality. This study focused on metals: Cd, Zn, Cu, Pb, Fe and Mn. These metals were chosen after previous studies reported finding them in first flush stormwater collected throughout the Midwestern US. This study tested the effectiveness of SR-HP forms to remove metals from DI water with standard solutions of metals added. Two sizes of SR-HP forms were constructed from sodium percarbonate (Na2CO3·1.5H2O2) salts and resin and release rates were quantified. The smaller size released hydrogen peroxide (H2O2) at a steady average rate of 0.063 mg/min after 6.2 hours. One proof-of-concept treatment test was conducted utilizing smaller SR-HP forms and DI water containing dissolved metals. During the treatment test, SR-HP released H2O2 and alkalinity at the rates ranging from 1.35 mM to 0.135 mM and 0.90 mM to 0.09 mM, respectively. The pH of metal loaded deionized water was raised from 1.74 to 1.87 indicating slight neutralization by added carbonate. This resulted in removal efficacies ranging from 4.17% - 0.65%, 4.52% - +0.76%, 8.59% - 2.92%, 7.44% – 0.29%, 0.52% - +2.24% for Cd, Cu, Fe, Pb and Zn respectively. No consistent treatment was evident for all metals except for iron, which saw a modest removal of 8.6%. This 8.6 removal was most likely due to Fe2+ being used during Fenton’s reaction. This result indicates effective removal by SR-HP could be feasible, especially if the pH is more alkaline. Further investigation of SR-HP form performance in a wide range of pHs could be possible.

Committee:

Eung Seok Lee (Advisor); Greg Nadon (Committee Member)

Subjects:

Analytical Chemistry; Aquaculture; Aquatic Sciences; Area Planning and Development; Chemical Engineering; Chemistry; Environmental Geology; Environmental Science; Environmental Studies; Experiments; Geology; Hydrologic Sciences; Hydrology; Organic Chemistry

Keywords:

Slow release; oxidation; stormwater; urban runoff; fentons; stormwater treatment; iron; manganese; zinc; cadmium; copper; lead; metal pollutants; treatment by oxidation; pH; Hydrogen peroxide

Budnik, Richard RAssessment of Site-Fidelity and Straying in Lake Erie Steelhead Trout
Doctor of Philosophy (Ph.D.), Bowling Green State University, 2017, Biological Sciences
This dissertation examines straying in Lake Erie steelhead (Oncorhynchus mykiss) and investigates how stocking practices can influence the propensity of steelhead to stray. The Lake Erie steelhead fishery generates millions of dollars in revenue each year for local economies in New York, Ohio, Pennsylvania, Michigan, and the province of Ontario. This fishery is overwhelmingly dominated by stocking from each of the four contiguous US states, and approximately 1.8 million juvenile steelhead are stocked each year to sustain population numbers. River-spawned salmonids generally exhibit high rates of philopatry, while for stocked fish straying rates of up to 15% are common. In Chapter I, we quantify the proportion of straying adult steelhead in five Lake Erie tributaries using state-hatchery specific otolith chemical signatures to identify sources. We also investigate the prevalence of naturally produced fish and identify spatial differences in the proportion of strays at different stream locations within two Lake Erie tributaries. Because straying proportions were found to be high in New York, in Chapter II an otolith back-calculation method was used to investigate the influence of size at stocking on the survival of juvenile steelhead released by the New York hatchery program. In Chapter III, we investigate additional drivers of straying by using dual-frequency identification sonar (DIDSON) to estimate survival and tributary residence time of juvenile steelhead stocked into a small Lake Erie tributary. Patterns in emigration, and the role of environmental factors and individual size on emigration timing were also investigated. In Chapter IV, we identify the prevalence of aragonite versus vaterite sagittal otoliths in steelhead raised in Lake Erie hatcheries. We then present a technique to use sagittal otoliths that have transitioned from aragonite to vaterite to help develop otolith chemistry signatures of steelhead from different hatchery sources in Lake Erie. This research was an attempt to identify potential drivers of straying in Lake Erie steelhead. From an applied management perspective, we attempted to identify straying proportions in different Lake Erie tributaries and examine how differential stocking practices may influence overall survival and return rates. Straying is a complex process driven by a number of different biotic and abiotic factors. The identification of mechanisms that increase straying, especially those which can be controlled by hatchery managers, would be invaluable and greatly advance our ability to manage steelhead populations.

Committee:

Jeffrey Miner (Advisor); Kevin Pangle (Committee Member); Wiegmann Daniel (Committee Member); Moore Paul (Committee Member); Gomezdelcampo Enrique (Other)

Subjects:

Aquatic Sciences; Biology; Ecology; Fish Production; Freshwater Ecology

Keywords:

steelhead; Lake Erie; straying; otolith microchemistry; LA-ICP-MS; otolith back-calculation; DIDSON; vaterite

Clark, JessicaThe Sensory Mechanisms of Crayfish (Orconectes rusticus) Used in Detecting Predatory Threats
Master of Science (MS), Bowling Green State University, 2017, Biological Sciences
Organisms are exposed to numerous environmental stimuli in which they must be able to distinguish threats from food sources. In order to make such distinctions, organisms rely upon sensory mechanisms, including chemoreception, vision, and mechanoreception. With the reception of chemical, visual, and/or mechanical cues prey species can determine the location, size, and movement of a nearby predator. Then, with the information gathered, prey can determine the severity of the threat and respond accordingly, whether to flee or to display a defensive stance. Various studies suggest that several aquatic species, including crayfish, rely on the integration of sensory modalities to accurately assess predatory threats. This study aimed to determine whether a hierarchy in the reliance upon sensory modalities exists in crayfish (Orconectes rusticus) and if this hierarchy is altered across different sensory environments (such as flowing and non-flowing environments). We also sought to determine the significance of sensory multimodality in crayfish. To study the relevance of each of the sensory modalities, as well as the integration of these modalities, in crayfish combinations of lesions/blocks were conducted. Two sensory mechanisms (chemical and mechanical, chemical and visual, or visual and mechanical) were lesioned/blocked at once, leaving one sensory mechanism (vision, mechanoreception, or chemoreception) functional. Each of the crayfish were then exposed to a predatory largemouth bass (Micropterus salmoides) in either a flowing or non-flowing stream where their behavior was recorded for 30 minutes. The behaviors and movements of the crayfish were then analyzed with the use of Ethovison Noldus XT. Linear mixed models were then conducted to determine the impact of the lesions, flowing environments, and the combination of iv the lesions and flowing environments on the ability of crayfish to detect predatory stimulus. Significant Least Squares Means (LSM) test were followed by Type II Wald Chisquare tests. Results from this study support the significance of sensory multimodality in crayfish for accurately detecting and assessing predatory threats. When the sensory multimodality of crayfish was eliminated the animals were challenged to successfully assess the severity of the predator. Crayfish with only the full use of chemoreceptors or mechanoreceptors showed a greater avoidance of the predator, indicating that these individuals could detect the threat but could not accurately locate the source. Results from this study also suggest that a hierarchy in the reliance upon sensory modalities does exist in crayfish, with a bias towards chemoreception, followed by mechanoreception, and finally vision.

Committee:

Paul Moore (Advisor); Jeffrey Miner (Committee Member); Daniel Wiegmann (Committee Member)

Subjects:

Aquatic Sciences; Behavioral Sciences; Biology; Ecology

Keywords:

sensory modalities; multimodality; sensory hierarchy; crayfish;predator-prey interactions; nonconsumptive effects

Sieracki, Jennifer L.Spatial Modeling as a Decision-making Tool for Invasive Species Management in the Great Lakes
Doctor of Philosophy, University of Toledo, 2014, Biology (Ecology)
Due to recent recognition that ballast water is playing an important role in the spread of invasive species within the Great Lakes, there has been increasing interest in implementing management strategies that include a secondary spread component for ballast discharge. Using ballast water data for ships visiting U.S. ports in the Great Lakes, I created a dynamic spatial model to simulate the spread of invasive species based on recent shipping patterns. My goal in producing this model was to provide information to natural resource managers, scientists, and policy-makers to help effectively regulate invasive species issues. In testing the model, I determined that including the number of discharging ship visits that a location receives from previously infested areas and the ability of an organism to survive in the ballast tank were important in more accurately identifying the past spread of the fish virus, viral hemorrhagic septicemia virus (VHSV), zebra mussel (Dreissena polymorpha), and Eurasian Ruffe (Gymnocephalus cernuus), than discharge location alone. I also included and tested a localized spread distance that simulated the dispersal of an invasive species upon being discharged at a location. I first applied the model to identify if ballast water played a role in the secondary spread of VHSV. Results indicated that ballast water movement has contributed to the spread of VHSV in the Great Lakes, albeit it is not the only vector of secondary spread. However, ballast water management would be an important part of any plan in preventing the future spread of VHSV in an ecosystem. Next, I applied the model to predict the future spread of Eurasian Ruffe, which already occurs in the Great Lakes, and two species that do not, golden mussel (Limnoperna fortune) and killer shrimp (Dikerogammerus villosus). The results of the prediction models are intended to be used to help direct early detection monitoring efforts. The Eurasian Ruffe results are currently being used by The Nature Conservancy in their eDNA monitoring efforts, and have led to the positive detection of ruffe eDNA in a location where ruffe has previously not been detected. Finally, I applied the model to identify potentially “safe” ballast water exchange (BWE) sites in Lake Michigan. The purpose of this exercise was to locate mid-lake sites where ships could exchange and flush their ballast tanks, so as to reduce the probability that species are able to survive and establish new populations in the Great Lakes. Potential BWE sites were identified by inputting the results of Lake Michigan circulation models into the ballast water model to determine which sites led to no or minimal spread throughout the Great Lakes. Results of model applications have led to specific predictions for species and management scenarios identified by invasive species managers that have previously not been made for ballast water management in the Great Lakes before.

Committee:

Jonathan Bossenbroek, PhD (Committee Chair); Peter Lindquist, PhD (Committee Member); Christine Mayer, PhD (Committee Member); Darryl Moorhead, PhD (Committee Member); David Reid, PhD (Committee Member)

Subjects:

Aquatic Sciences; Ecology; Environmental Science

Keywords:

invasive species; ballast water; spatial modeling; Laurentian Great Lakes; secondary spread

Hayes, Nicole MClimate and watershed land use as drivers of change in phytoplankton community structure and ecosystem function
Doctor of Philosophy, Miami University, 2015, Ecology, Evolution and Environmental Biology
The goal of my dissertation was to understand how phytoplankton, specifically cyanobacteria respond to the individual and interactive effects of land use change and climate change. Chapter 1: Climate and land use interactively affect lake phytoplankton nutrient limitation status. Climate change models predict more frequent and intense summer droughts and precipitation events, which could modify the rates and ratios at which nitrogen (N) and phosphorus (P) enter lakes. However, watershed land use also determines nutrient run off. I found that phytoplankton in lakes with forested watersheds were consistently N-limited. While, phytoplankton in lakes with agricultural watersheds were typically P-limited, they switched to N-limitation during drought. This interaction suggests that droughts would increase the incidence of N-limitation and likely impair valuable ecosystem services. Chapter 2: Increased light and gizzard shad excretion maintain high phytoplankton biomass in a eutrophic reservoir despite watershed management. Conservation tillage aims to control soil and fertilizer loss from agricultural fields with the added benefit of reducing nutrient run-off into nearby lakes. With a 20 year dataset I found that chlorophyll increased following conservation tillage as a result of decreased light limitation (less sediment) and increased internal nutrient cycling by a dominant detritivorous fish. Chapter 3: Phytoplankton community composition, reservoir morphometry, and nutrient concentrations predict microcystin concentrations. Cyanobacteria toxins are a primary concern of eutrophication management but efforts to predict toxin concentrations have implicated numerous physical and chemical variables. I found that shallow reservoirs with high internal nutrient cycling had elevated toxins, implicating lake morphometry as a driver of water quality. Chapter 4: Abundant nitrogen not nitrogen limitation promotes cyanobacteria and microcystin. The importance of nitrogen limitation versus abundant nitrogen in promoting cyanobacteria is contested in the literature. In a mesocosm study I tested the importance of N:P supply ratio by manipulating light, P supply, and the N:P supply ratio and measuring cyanobacteria biomass, nitrogen fixation, and microcystin production. I found that all three variables were elevated when primary production was highest, under high light/high P supply/high N:P supply ratio suggesting that the most nutrient and light rich conditions favor cyanobacteria.

Committee:

Michael Vanni, J (Advisor); Maria Gonzalez, J (Committee Member); Thomas Crist, O (Committee Member); Martin Stevens, H (Committee Member); Rachael Morgan-Kiss, M (Committee Member)

Subjects:

Aquatic Sciences; Biogeochemistry; Ecology; Limnology

Keywords:

climate change; land use; cyanobacteria; phytoplankton; nitrogen fixation; microcystin; toxin production; nutrient limitation; ecosystem process

Brentrup, Jennifer AThe role of water transparency in regulating carbon dynamics in lakes: Experimental, comparative, and high-frequency approaches
Doctor of Philosophy, Miami University, 2017, Ecology, Evolution and Environmental Biology
Chapter 1: Comparing the relative importance of photodegradation and biodegradation for transforming dissolved organic matter quality in three temperate lakes of varying trophic status. In this chapter, I tested the relative importance of photodegradation vs. biodegradation for altering dissolved organic matter (DOM) quality and quantity from three temperate lakes ranging in color and productivity. For all three lakes, photodegradation led to larger decreases in DOM color and molecular weight than biodegradation. In addition, DOM with low prior sunlight exposure responded more to photodegradation than previously sunlight exposed DOM. This chapter is currently in preparation for submission to the Journal of Geophysical Research: Biogeosciences. Chapter 2: Sunlight-driven degradation of terrestrial organic matter exceeds microbial respiration. For Chapter 2, I extended Chapter 1 by more completely exploring how sunlight and microbes control the production of CO2 for terrestrial DOM from the watershed surrounding the same temperate lakes and a sub-tropical lake. Here we show that sunlight led to higher amounts of CO2 production than microbial respiration for terrestrial DOM from the watersheds of the brown-water lakes. However, sunlight-driven reductions in DOM quality were greater than CO2 production for DOM from the watersheds of the oligotrophic and eutrophic lakes. This chapter is in preparation for submission to Biogeochemistry. Chapter 3: The potential of high-frequency profiling to assess vertical and seasonal patterns of phytoplankton dynamics in lakes: an extension of the Plankton Ecology Group (PEG) model Here, I compared nightly profiles of chlorophyll fluorescence (proxy for phytoplankton biomass) from 11 global lakes to test the drivers of seasonal changes in sub-surface phytoplankton layers. High-frequency profiles captured the short-term phytoplankton dynamics better than traditional sampling, and physical drivers including light availability and thermal stratification were important determinants of when sub-surface phytoplankton layers form. This research was published as part of the GLEON special issue in Inland Waters. (Brentrup et al. 2016) Chapter 4: Drivers of metalimnetic oxygen maxima in lakes: the importance of physical processes. In this chapter, I tested the relative contributions of physical and biological processes for metalimnetic oxygen maxima (MOM) formation. We found that physical processes played a larger role in MOM formation than previously thought, especially in transparent, oligotrophic lakes. Net ecosystem production at the MOM was also typically net heterotrophic, suggesting a stronger physical rather than biological signal and high rates of respiration. This chapter is in preparation for submission to Limnology and Oceanography.

Committee:

Craig Williamson (Advisor)

Subjects:

Aquatic Sciences; Biology; Ecology

Keywords:

lakes; carbon; biogeochemistry; transparency; phytoplankton; sensors

Embke, Holly SusanAssessing the Spawning Potential of Grass Carp in the Sandusky River Under Varying Conditions
Master of Science, University of Toledo, 2017, Biology (Ecology)
Invasive Grass Carp (Ctenopharyngodon idella) have been stocked for decades in the United States for vegetation control. Adults have been found in all of the Great Lakes except Lake Superior, but no self-sustaining populations have yet been identified in Great Lakes tributaries. Previous research suggested natural reproduction has occurred in the Sandusky River; hence I sampled ichthyoplankton using bongo net tows and larval light traps June through August 2015 and 2016 to determine if Grass Carp were spawning. I identified and staged eight eggs that were morphologically consistent with Grass Carp. Five eggs were confirmed as Grass Carp using quantitative PCR and DNA sequencing, while three were retained for future analysis. All eggs were collected during high-flow events, either on the day of or 1-2 days following peak flow, supporting a suggestion that high-flow conditions favor Grass Carp spawning. From my egg collection findings, I used hydraulic modeling to estimate the most probable spawning and hatching locations for these eggs. Preliminary model results suggest eggs were most likely released near the hypothesized spawning site near Fremont, Ohio at river km 21.25. Hatch locations were near the mouth of the Sandusky River at Muddy Creek Bay, with the majority of eggs likely hatching at river km 2.9. These locations will help guide future sampling efforts, inform risk assessments and aid targeted control efforts.

Committee:

Christine Mayer (Committee Co-Chair); Song Qian (Committee Co-Chair); Patrick Kocovsky (Committee Member); Seth Herbst (Committee Member)

Subjects:

Aquatic Sciences; Biology; Ecology; Environmental Science; Freshwater Ecology

Keywords:

Great Lakes; invasive species; hydraulic modeling

Bonini, NickAssessing the Variability of Phytoplankton Assemblages in Old Woman Creek, Ohio
PHD, Kent State University, 2016, College of Arts and Sciences / Department of Geology
Various techniques for assessing, monitoring, and predicting algal blooms in an estuarine ecosystem are analyzed. In one section, routine water samples are collected at previously established monitoring sites in Old Woman Creek, filtered onto a 47 mm, 0.7 µm glass-fiber filter (GF/F), and then measured using a visible/near-infrared spectrophotometer. Varimax-rotated principal component analysis (VPCA) is applied to reflectance data and then used to quantify and identify pigments, phytoplankton taxa, and sediments by comparing the measured spectral signatures to known standards. Common assemblages that are reported throughout the three-year study include: bacillariophyceae (diatoms), chlorophyta (green algae), cyanobacteria (blue-green algae), and illite. A similar approach is taken in the next section by applying multivariate statistics to Landsat 8 satellite imagery in order to determine the distribution of in-water constituents at a high spatial resolution. Only four bands in the visible range are available for this analysis, but it is possible to identify several of the same groups of algae and sediments, providing a useful complement to the hyperspectral work. Finally, a bloom prediction model based on springtime discharge is created by applying VPCA to in-water sonde data from one of the monitoring sites at Old Woman Creek during a recent 11-year time period. In this model, a proxy for net community production (NCP) is determined using oxygen and pH dynamics and then compared to daily rates of streamflow. Possible monthly sequences between January and June are considered in order to determine which timeframe is the best indicator of the average annual NCP. Time of day (daytime versus nighttime) and mouth bar conditions (barrier beach present versus absent) are important factors in determining production in the estuary. Based on the results, the best predictor for NCP is stream discharge from March through May, which produces correlations that are significant at even the 1% level. A positive relationship is found between NCP and discharge when flow from Old Woman Creek into Lake Erie is permitted. When flow is blocked by the barrier beach, however, the relationship is reversed.

Committee:

Joseph Ortiz (Advisor); Anne Jefferson (Committee Member); Alison Smith (Committee Member); Darren Bade (Committee Member)

Subjects:

Aquatic Sciences; Biological Oceanography; Environmental Geology; Environmental Science; Geology; Limnology; Water Resource Management

Keywords:

Old Woman Creek; Lake Erie; algal blooms; phytoplankton; water quality; estuary; barrier beach; VNIR derivative spectroscopy; VPCA; principal component analysis; remote sensing; prediction model; net community production; streamflow

Li, WeiINFLUENCE OF ENVIRONMENTAL DRIVERS AND INTERACTIONS ON THE MICROBIAL COMMUNITY STRUCTURE IN PERMANENTLY STRATIFIED MEROMICTIC ANTARCTIC LAKES
Doctor of Philosophy, Miami University, 2016, Ecology, Evolution and Environmental Biology
The microbial loop plays important roles in the cycling of energy, carbon and elements in aquatic ecosystems. Viruses, bacteria, Archaea and microbial eukaryotes are key players in global carbon cycle and biogeochemical cycles. Investigating microbial diversity and community structure is crucial first step for understanding the ecological functioning in aquatic environment. Meromictic lakes are bodies of water and exhibit permanent stratification of major physical and chemical environmental factors. Microbial consortia residing in permanently stratified lakes exhibit relatively constant spatial stratification throughout the water column and are adapted to vastly different habitats within the same water. Pristine perennially-ice-covered lakes (Lake Bonney, Lake Fryxell and Lake Vanda) are meromictic lakes located in the McMurdo Dry Valleys (MDV) of Southern Victoria Land, Antarctica. The lakes have isolated water bodies and extremely stable strata that vary physically, chemically, and biologically within and between the water columns. The unique characteristics support microbially dominated food webs in these lakes. In the research presented here, we gathered new understanding of how environmental drivers influence microbial community structure in these aquatic ecosystems. We explored the lake microbial ecology from three major approaches: 1). Assess trophic activities in the natural environment and identify potential environmental drivers impacting heterotrophic (ß Glucosaminidase) and autotrophic (Ribulose 1,5 bisphosphate carboxylase) enzyme activities; 2). Resolve the protist community composition (i.e. autotrophic, heterotrophic and mixotrophic groups) based on high throughput sequencing and bioinformatics. Identify how the community structures correlate with specific environmental and biological factors; 3). Reveal the diversity of potential microbial interactions between the microorganisms in the MDV lakes at individual cell level, and investigate how the interactions vary between organisms with different nutritional strategies. Studies of polar microbial communities on the cusp of environmental change will be important for predicting how microbial communities in low latitude aquatic systems will respond. This study expands the understanding of how environmental drivers interact with microbial communities in the Antarctica lakes, and provide new information to predict how the community structure will alter as response to climate changes.

Committee:

Rachael Morgan-Kiss (Advisor); Annette Bollmann (Committee Member); Thomas Crist (Committee Member); Michael Vanni (Committee Member); Richard Edelmann (Committee Member); Rebecca Gast (Committee Member)

Subjects:

Aquatic Sciences; Bioinformatics; Climate Change; Ecology; Environmental Science; Limnology; Microbiology

Ecrement, Stephen M.Amphibian Use of Man-Made Pools Created by Military Activity on Kisatchie National Forest, Louisiana
Master of Science (MS), Ohio University, 2014, Environmental Studies (Arts and Sciences)
Pools created from military training provide breeding habitat for many amphibian species. Six hundred and twenty four surveys were conducted for larval amphibians on 48 small man-made pools, created from military maneuver training (tank defilades), on the Fort Polk Intensive Use Area (IUA) of Kisatchie National Forest, Louisiana. Surveys were conducted monthly from April to early October 2012 and March to September 2013. Anuran species composition varied across tank defilades, with environmental variables explaining the presence and abundance of some species. Bronze frogs (Lithobates clamitans), Northern Cricket frogs (Acris crepitans), Fowler’s toads (Anaxyrus fowleri), Eastern Narrow-Mouthed toads (Gastrophryne carolinensis), Gray tree frog complex (Hyla versicolor/chrysoscelis), and Squirrel tree frogs (Hyla squirellii) were not abundant enough for analysis. Cajun Chorus frogs (Pseudacris fouquettei) and Southern Leopard frogs (Lithobates sphenocephalus) occurred in 79% of the pools. Salamanders were not encountered at the study site either year. Of seven variables evaluated using regression models, open canopy, low percent slope, and fish absence were positively related to the abundance of Cajun Chorus frogs (Pseudacris fouquettei). Percent dissolved oxygen and low canopy closure were positively associated with Southern Leopard frogs (Lithobates sphenocephalus) abundance. My results show that the two species use these man-made pools differently, highlighting the importance of having pools in varying conditions. In light of documented declines of anuran populations, it has become increasingly important to protect their breeding habitat. It is equally important to gain an understanding of habitat characteristics that attract or deter breeding amphibians from natural or man-made aquatic systems. Although these pools were created unintentionally they now serve as amphibian breeding habitat.

Committee:

Kelly Johnson (Advisor); Natalie Kruse (Committee Member); Matthew White (Committee Member)

Subjects:

Aquatic Sciences; Biology; Conservation; Environmental Science; Environmental Studies; Wildlife Conservation

Keywords:

amphibian conservation; man-made pools; pool-scale characteristics; Cajun Chorus frogs, Southern Leopard frogs, Louisiana, military activity

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