Master of Science, Miami University, 2005, Zoology

This study analyzed effects of storm intensity on turbidity, chlorophyll, abundance and population parameters of three Brachionus in a reservoir. I predicted chlorophyll and Brachionus abundance, growth rate, and birth rate would be negatively correlated with storm intensity. I expected positive correlations between storm intensity and non-volatile suspended sediments (NVSS) as well as Brachionus death rates. I used linear regression to relate NVSS and chlorophyll concentrations and changes in each parameter during and after storms to storm intensity. A significant positive correlation between NVSS and storm intensity was observed. Influence of storm events on Brachionus parameters was variable and species specific. During storms, significant positive correlations were observed between changes in B.calyciflorus abundance as well as in B.angularis growth rate with storm intensity. Significant negative correlations were observed between changes in B.angularis growth rate as well as in B.caudatus resting egg production with storm intensity during the post-storm period.

Committee: Maria Gonzalez (Advisor) Subjects:

Master of Science, Miami University, 2025, Biology

Periodical cicada emergence delivers an infrequent but large pulse of high-quality resources to ponds. Subsidy effects can be mediated by temperature, and freshwater ecosystems are warming. Thus, cicadas may subsidize warmer ponds in the future. I experimentally examined effects of cicada carcasses (added or not), and warming (ambient or warmed 2-3°C), and a combination of both treatments, on pond zooplankton biomass and composition, and phytoplankton biomass, and Z:P (zooplankton:phytoplankton) biomass ratios in a 6-week, 2x2 factorial design experiment using simulated ponds (1000-L tanks). Cicada addition caused a significant, short-lived increase of biomass of several zooplankton taxa, while warming effects were rarely significant. Similarity indices between initial and final zooplankton compositions showed population divergence with cicadas, and no effects of warming. Species composition shifted toward dominance of smaller taxa across all treatments by experiment's end. Warming and cicada addition had opposite effects on Z:P ratios. Cicada addition increased the Z:P ratio suggesting zooplankton exert more control over the ratio through increased biomass and grazing pressure. Warming decreased Z:P ratios, indicating higher respiration rates in zooplankton. Our results suggest that cicada subsides have transient effects on plankton communities and that 2-3°C warming is unlikely to affect subsidy use in small ponds.

Committee: María González (Advisor); Lesley Knoll (Committee Member); Hank Stevens (Committee Member); Michael Vanni (Committee Member) Subjects: Biology; Ecology

Master of Science, The Ohio State University, 1962, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Arts (MA), Bowling Green State University, 1959, Biological Sciences

Committee: Edward Karlin (Advisor) Subjects: Biology

Master of Arts (MA), Bowling Green State University, 1959, Biological Sciences

Committee: Edward Karlin (Advisor) Subjects: Biology

Master of Science, University of Toledo, 2022, Biology (Ecology)

Human-induced environmental change creates novel stressors which populations have not experienced over the course of their evolutionary histories. These stressors are unique selective pressures which may alter species' survival, growth, reproduction, or behaviors. Freshwater salinization is of growing interest in the scientific community because of the substantial increase in salinity concentrations from irrigation, mining runoff, groundwater pumping, and road salt use. Freshwater salinization is particularly harmful to zooplankton. Zooplankton are critically important to the health of freshwater ecosystems and maintaining ecosystem services such as fisheries, recreation, and clean drinking water. Recent research demonstrates that zooplankton may be capable of rapid adaptation to elevated salinity, which has implications for ecological stability. However, many questions remain regarding how changes in zooplankton tolerance to salinization alters survival, growth, reproduction, and behaviors. To address these important questions, I conduced two separate studies. My first chapter addresses how a multigenerational exposure to salt pollution alters the life history traits of zooplankton and if life history tradeoffs can promote ecological stability. I found that freshwater zooplankton are able to make life history tradeoffs to cope with low levels of salt stress. However, these tradeoffs only occurred in specific salt types and concentrations. Additionally, I found that prolonged, multigenerational exposure to salinity can lead to maladaptation where a long-term exposure history does not confer adaptation, but further reduces lifetime reproduction. My second chapter consists of two experiments to address how the non-consumptive effects of predation may interact with increased freshwater salinity, and a multigenerational exposure to salt pollution to affect 1) the population-level abundance of zooplankton, and 2) the anti-predatory escape behavior of zooplankton. I found (open full item for complete abstract)

Committee: William Hintz (Committee Chair); Christine Mayer (Committee Member); Jeanine Refsnider (Committee Member) Subjects: Aquatic Sciences; Biology; Ecology

Master of Science, Miami University, 2022, Biology

Lakes in the northeastern US are browning or increasing in dissolved organic carbon (DOC) as they recover from acidification and experience an increase in precipitation from climate change. DOC attenuates ultraviolet radiation (UV), reducing exposure of lake zooplankton to damaging wavelengths in browner lakes. Additionally, some zooplankton can detect and avoid UV. DOC's role in the cladoceran Holopedium's survival was tested by exposing organisms to natural solar radiation in the presence vs. absence of DOC. It was hypothesized that when exposed to natural UV, the presence of DOC would increase survival in Holopedium. Additionally, if Holopedium could behaviorally detect and avoid UV or visible light was also investigated. Survival was significantly higher in treatments exposed to UV in the presence vs. absence of DOC. There was no evidence of behavioral response to UV or visible light. These results convey the importance of DOC protecting Holopedium from UV damage as they can inhabit in the surface waters of some lakes, partially due to a defense against tactile predators. Browning may also mediate the potential for resource partitioning between Holopedium and its competitor Daphnia. Predicted increases in browning caused by climate change may continue to alter these patterns.

Committee: Craig Williamson (Advisor); María González (Committee Member); Thomas Fisher (Committee Member) Subjects: Biology; Climate Change; Ecology; Limnology

Master of Science (MS), Bowling Green State University, 2020, Biological Sciences

Understanding the role of internal top-down trophic grazing interactions from zooplankton is necessary to better determine cyanobacterial algal bloom establishment as a parallel to more common investigation into the role of changes in nutrient concentrations, or bottom-up enrichment, on bloom structure and function. Bi-weekly samples were collected from two locations in Sandusky Bay, Lake Erie between March 2019 to October 2019 to capture pre-bloom, early-bloom, and late-bloom conditions. For microzooplankton analysis, dilution experiments were conducted to determine grazing rates using previously established methods. Mesozooplankton grazing rates were determined by concentrating natural populations to 8 times ambient levels, then measuring phytoplankton growth rate changes. After 24 hours samples for both experiments were collected for analysis of total chlorophyll ɑ pigment concentration using fluorometry and analysis of chlorophyll ɑ pigment concentration as well as phytoplankton community structure using a BBE Fluoroprobe. Phytoplankton cell enumeration using light microscopy was also conducted to determine cyanobacterial cell densities. This research also provided additional insights into correlations of chlorophyll ɑ data analysis between fluorometry and BBE Fluoroprobes. Results indicated that microzooplankton were actively grazing on the overall phytoplankton community in the majority of experiments conducted and that microzooplankton grazing rates were not negatively affected by increases in cyanobacterial density. In contrast mesozooplankton grazing rates were extremely low or no grazing was seen in the majority of experiments. Overall, this study indicated that while microzooplankton can play an important role, mesozooplankton grazing may not, in the top-down control of Planktothrix-dominated blooms in Sandusky Bay, Lake Erie.

Committee: Timothy Davis Dr. (Advisor); Thomas Bridgeman Dr. (Committee Member); George Bullerjahn Dr. (Committee Member) Subjects: Biology; Ecology; Environmental Science; Limnology; Microbiology; Water Resource Management

Master of Science, Miami University, 2020, Biology

Shifts in forest composition could have significant effects on freshwater zooplankton due to changes in quality of inputs of terrestrially-derived Dissolved Organic Matter (DOM). DOM has been shown to have concentration dependent effects on primary production, but no consistent concentration dependent effects on zooplankton growth rates, raising questions about the potential importance of DOM source. Red maple (Acer rubrum), a native tree, and Amur honeysuckle (Lonicera maackii), an invasive shrub, were used to test the effects of DOM source on juvenile Daphnia ambigua. Amur honeysuckle-derived DOM was expected to have greater negative effects. Bioassays were conducted in the presence or absence of algae with no additional DOM, or red maple or Amur honeysuckle-derived DOM. Both Amur honeysuckle and red maple had negative effects on growth rates in the presence of algae with red maple inducing significantly lower growth rates. Red maple-derived DOM also had negative effects on survival. The negative effects seen in the presence and absence of algae provided evidence for both indirect effects likely due to phytotoxicity and direct negative effects respectively. Future studies accounting for DOM source could enhance our understanding of the complex roles of DOM in regulating consumers in aquatic ecosystems.

Committee: Craig Williamson (Advisor); Maria Gonzalez (Committee Member); Karsten Mauer (Committee Member) Subjects: Biology; Ecology; Freshwater Ecology; Limnology

Bachelor of Science, Ashland University, 2019, Biology/Toxicology

Plastic pollution has been a growing global issue since the production and widespread consumption of plastic began more than 60 years ago. Over time, detrimental impacts on ter-restrial and aquatic organisms have been observed. Microplastics are plastic pieces or fibers (less than 5 mm) that contaminate aquatic systems and may impact zooplankton, aquatic ani-mals that naturally ingest phytoplankton and other food particles of a similar size. Zooplankton are consumed by fish, so organisms higher in the food web are expected to be impacted by zo-oplankton ingestion of microplastics as those plastics consumed by zooplankton are trans-ferred to the predatory fish and thus bioaccumulate through the trophic food web. This study investigated the potential of the model zooplankton, Daphnia magna, to ingest microplastic spheres and microfibers through concentration and extended exposure experiments. D. magna are a large species and were found to readily ingest polystyrene spheres 50µm in size. Since D. magna demonstrated an affinity for sphere ingestion, animals were exposed to the more com-mon contaminant, microfibers, to determine if ingestion occurred and if there were impacts on survival and reproduction. Despite a lack of fiber ingestion, Daphnia exposure to low levels of microfibers over twenty days showed a reduction in the number of eggs generated in a clutch, reduction in the viability of neonates that gestate to term, and reduction in the overall number of neonates. Microplastics may pose a harm not only to organisms such as D. magna but also to organisms higher in the trophic system through bioaccumulation and reduction in available zooplankton as a food source if reproductive success is decreased when exposed. Further stud-ies of native organisms are necessary to establish the effects of microplastic pollution on freshwater systems and the organisms that rely on them.

Committee: Jenna Dolhi Binder Ph.D. (Advisor); Patricia Saunders Ph.D. (Advisor); Jeffrey Weidenhamer Ph.D. (Advisor) Subjects: Biology

Doctor of Philosophy, Miami University, 2017, Ecology, Evolution and Environmental Biology

Food chain efficiency (FCE) is an important ecological phenomenon, and previous work has demonstrated that the light and nutrient supply into an aquatic system affects FCE via changes in algal quantity and quality. However, less work has focused on how carnivore characteristics influence FCE. My dissertation research examines how bottom-up and top-down effects interact to constrain FCE. Aquatic ecosystems are often phosphorus (P) limited; therefore, consumers with high body P content may suffer decreased growth. In chapter 1, I report on an experiment conducted to test the effects of light and nutrient supply and carnivore identity on FCE using two carnivores with differing body P content. I found that FCE was constrained by different factors in food chains with different carnivores, indicating that carnivore identity impacts FCE. P limitation may be a more important driver of FCE in early vertebrate carnivore ontogeny, as many larval fish undergo a dramatic increase in body P content as they develop bones. Chapter 2 describes a mesocosm experiment in which I found that even in the larval stage bluegill are highly sensitive to food quantity. I also found that FCE increased with increased abundance of basal resources, further emphasizing the importance of energy limitation in constraining FCE. Not only are the rates of nutrient supply important for FCE, but the ratio of N to P supply (N:P) can also influence the quantity and quality of algae as a food resource. In chapter 3 I evaluated how light, P supply, and N:P supply affected FCE. I found that N:P supply did not affect FCE, suggesting that algal communities may be able to buffer the effects of high or low N:P supply. The algae – herbivore link is the most important trophic coupling in determining FCE due to a greater mismatch between producer and herbivore stoichiometry. If herbivore growth decreases due to energy or nutrient limitation, overall FCE also decreases. In chapter 4 I used Daphnia growt (open full item for complete abstract)

Committee: Maria Gonzalez (Advisor); Michael Vanni (Committee Member); Thomas Crist (Committee Member); Michelle Boone (Committee Member); M.H.H. Stevens (Committee Member) Subjects: Aquatic Sciences; Ecology

Doctor of Philosophy, Miami University, 2016, Ecology, Evolution and Environmental Biology

Planktonic organisms are a globally important component of aquatic ecosystems whose ecological role is largely dependent upon their habitat use and patterns of spatial distributions. In this dissertation I present four independent but related chapters that explore the causes and consequences of spatial dynamics of phytoplankton and zooplankton in freshwater lakes. Chapter 1: Relative importance of light and thermal stratification to the structure of deep chlorophyll maxima in 100 GLEON lakes. Vertical distributions of chlorophyll in many lakes frequently exhibit ecologically important deep chlorophyll maximum (DCM). Using a 100-lake dataset, this chapter examines DCM structure and shows that light was the most important predictor of DCM depth, while the thickness of the DCM was best predicted by lake size. Importantly, the analysis also suggests that the importance of these drivers varies across lakes. This chapter is part of an international collaboration through the Global Lakes Observatory Network (GLEON) and is in preparation for submission to Limnology and Oceanography. Chapter 2: The role of ultraviolet radiation in the diel vertical migration of zooplankton: an experimental test of the transparency- regulator hypothesis. The transparency-regulator hypothesis (TRH; Williamson et al. 2011) posits that the relative importance of abiotic vs. biotic drivers of zooplankton diel vertical migration will vary systematically across a gradient of lake transparency. This chapter provides experimental support of the TRH tests using mesocosm experiments in a set of fish- and fishless-lakes that span a range of transparency. This chapter was published in the Journal of Plankton Research in 2015 (Leach et al. 2015). Chapter 3: Does vertical habitat quality influence large-scale horizontal distributions of organisms in pelagic ecosystems? In this chapter I use hydroacoustics to test the hypothesis that the depth of lake ecosystems regulates zooplankton optimal hab (open full item for complete abstract)

Committee: Craig Williamson (Advisor); A. John Bailer (Committee Member); Janet Fischer (Committee Member); Melany Fisk (Committee Member); Michael Vanni (Committee Member) Subjects: Ecology; Limnology

MS, Kent State University, 2016, College of Arts and Sciences / Department of Biological Sciences

Through close interactions with biotic and abiotic environments, microbial communities in lakes mediate numerous biogeochemical processes that are essential in regional and global cycles of C, N and P. However, the relationship between bacterial community compositions and environmental conditions is still unclear. Lake Erie's natural gradient of nutrient supply and many other environmental parameters from the Sandusky Bay to the Central Basin provides an ideal experiment to examine how well bacterial community composition tracks environmental changes spatially and temporally. Surface water samples were collected along a transect that ran from the Sandusky Bay (hypereutrophic) via Sandusky Sub-basin (mesoeutrophic) to the Central Basin (oligotrophic) in June, July and August 2012. Zooplankton sample were also collected at each basin in June, July and August to see whether they respond to environmental conditions and to the changing bacterioplankton communities. Physico-chemical parameters were measured in situ. Bacterioplankton was collected on filters and filtrates were used for nutrient analyses, including ammonium, dissolved organic carbon, total dissolved nitrogen, nitrate, nitrite and soluble reactive phosphorus. Chlorophyll a concentration measurements confirmed the expected gradient of primary productivity among sites. Terminal restriction fragment length polymorphism (T-RFLP) analysis was conducted to compare of the microbial community structure and diversity along this natural gradient from the Sandusky Bay to the Central Basin. Additionally, zooplankton community structure and diversity was compared along the transect. Results showed that the free-living bacterioplankton structure differed significantly among sampling time, which was likely contributed by temporal variations in nutrient concentrations. As for the zooplankton community, Cyclopidae, Branchionidae and Synchaetidae were identified as major families (>78.4% of total zooplankton) in all samples. (open full item for complete abstract)

Committee: Xiaozhen Mou (Advisor) Subjects: Aquatic Sciences; Biogeochemistry; Biology; Conservation; Ecology; Environmental Science; Experiments; Freshwater Ecology; Limnology; Microbiology; Molecular Biology; Toxicology

Doctor of Philosophy, The Ohio State University, 2004, Evolution, Ecology, and Organismal Biology

Herein, I provide a water quality monitoring tool for the offshore waters of Lake Erie. The Planktonic Index of Biotic Integrity (P-IBI) was developed using Lake Erie zooplankton and phytoplankton data. I reviewed literature related to Indices of Biotic Integrity and plankton ecology (Chapter 1). To construct a valid IBI, I conducted temporal and spatial analyses for different parameters of Lake Erie plankton and plankton sampling regimens (Chapter 2). Using this information, I then determined appropriate temporal and spatial sampling frequency needed for the P-IBI. Further, using Lake Erie monitoring data I provide information on the invasive predatory cladoceran, Cercopagis pengoi (Chapter 3), and on the temporal and spatial distribution of Limnocalanus macrurus (Chapter 4), a pollution intolerant calanoid copepod. The P-IBI was developed using phytoplankton and zooplankton data from 1970 and 1996, validated with respect to total phosphorus and chlorophyll a concentrations, and applied to approximately 10 years of Lake Erie plankton data (Chapter 5). P-IBI candidate zooplankton metrics included an abundance ratio of calanoid copepods to cladocerans and cyclopoid copepods, percentage density of large Daphnia, rotifer composition, density of the calanoid copepod Limnocalanus macrurus, percentage biomass of the predatory invasive zooplankters Bythotrephes and Cercopagis, biomass of crustacean zooplankton/ biomass of phytoplankton, and biomass of crustacean zooplankton. Candidate phytoplankton metrics included a generic index of diatoms, abundance ratio of centric diatoms to pennate diatoms, biomass of inedible algae taxa, percentage biomass of bluegreen algae of the total phytoplankton biomass, percentage biomass of the potentially toxic Microcystis, Anabaena, and Aphanizomenon of total phytoplankton biomass, and biomass of edible algae taxa.

Committee: David Culver (Advisor) Subjects: Biology, Limnology

Master of Science, Miami University, 2010, Zoology

Proper management of aquatic systems requires knowledge of the links among landscape-level anthropogenic disturbances, terrestrial subsidies, and aquatic ecosystem properties. Due to their large watershed area to surface area ratios, reservoirs often receive substantial subsidies of nutrients and sediments. To better understand relationships between environmental variables and reservoir ecosystem properties, we examined relationships among variables representing landscape-level features, reservoir morphometry, water quality parameters and zooplankton community biomass for 109 reservoirs spanning a wide productivity gradient. A principal components analysis (PCA) identified two significant environmental gradients, the first representing reservoir productivity and land use cover and the second representing reservoir morphometry. A regression tree analysis used landscape-level and morphometric parameters to classify reservoirs according to their productivity level into four groups. Significant correlations were detected between small-bodied zooplankton (rotifers and/or copepod nauplii) and several environmental parameters. Non-metric multidimensional scaling plots identified a separation between reservoirs in the highest and lowest productivity groups, but only for rotifer communities.

Committee: María J. González (Advisor); Martin H. H. Stevens (Committee Member); Michael J. Vanni (Committee Member); William H. Renwick (Committee Member) Subjects: Ecology

Master of Science, Miami University, 2007, Zoology

The biomass, production, and community composition of zooplankton are affected by many factors, such as food quantity, quality, and predation. In this study, we investigated the effects of light and nutrients on phytoplankton food quantity (chl-a) and quality (stoichiometric and taxonomic) and subsequent effects on zooplankton communities and food chain efficiency in the presence and absence of fish predation. The relative supply of light and nutrients had strong effects on phytoplankton food quantity and quality, and these parameters explained much variation in zooplankton community response. Zooplankton communities were also strongly affected by planktivory. Both the stoichiometric and taxonomic food quality of the phytoplankton, as well as the community composition of the zooplankton affected food chain efficiency across three trophic levels. This study highlights the importance of considering not only the effects of primary producers, but also of intermediate trophic levels on food web processes.

Committee: Maria Gonzalez (Advisor) Subjects: Biology, Limnology

MS, Kent State University, 2011, College of Arts and Sciences / Department of Biological Sciences

Invasive non-indigenous (NI) zooplankton are a concern in aquatic systems since they can prey on native species, outcompete natives for resources, parasitize or host parasites that negatively affect natives, and cause shifts in native zooplankton communities that can cause changes in the trophic structure of lakes. Eubosmina coregoni is a NI zooplankter that is native to lakes in Northern Europe and Russia and has invaded the Laurentian Great Lakes and inland lakes within 100 km of the Great Lakes. This study used a combination of literature review and experimental manipulations to better understand the factors involved in the establishment of Eubosmina coregoni in the Twin Lakes (Portage County, OH) and the consequences of its presence in lake ecosystems. Historical data collected from the Twin Lakes show that E. coregoni was discovered in East Twin Lake in 1976, four years after surrounding septic tanks were diverted and connected to main municipal sewer systems, and one year after an aluminum sulfate treatment applied to West Lake. E. coregoni has since spread to West Twin Lake and has become the most dominant zooplankter in both these lakes. Experimental trials involving two common predators in the Twin Lakes, Chaoborus punctipennis and Lepomis macrochirus, and mixtures containing E. coregoni and B. longirostris, a close relative of E. coregoni and native zooplankter in the Twin Lakes, were performed to assess predator preference. C. punctipennis significantly preferred the native B. longirostris over the NI E. coregoni in every trial (p < 0.001), whereas Lepomis macrochirus did not show any preference for either species (p > 0.05). Measurements were also performed on the carapace height and length of both E. coregoni and B. longirostris to determine the presence of cyclomorphosis, a type of phenotypic plasticity that can possibly act as an anti-predator defense. Seasonal differences in the proportion of height to length were found in E. coregoni but not B. long (open full item for complete abstract)

Committee: Darren Bade PhD (Advisor); Mark Kershner PhD (Committee Member); Patrick Lorch PhD (Committee Member) Subjects: Aquatic Sciences

PHD, Kent State University, 2009, College of Arts and Sciences / Department of Biological Sciences

A recent invader to Ohio is the cladoceran, Daphnia lumholtzi which was first reported in the state in 1993. A survey of 93 lakes and reservoirs was used to investigate the current distribution of D. lumholtzi in Ohio. Analysis of these samples revealed that D. lumholtzi has established in 19 of the waterbodies surveyed. Surface area was the only abiotic characteristic that exhibited a significant difference between invaded and non-invaded localities, thus it seems unlikely that local environmental conditions prohibit the invasion of D. lumholtzi. Additionally, it was found that D. lumholtzi is associated with smaller sized zooplankton communities. These results suggest that interactions with the native species, rather than abiotic characteristics, may be responsible for controlling the establishment of D. lumholtzi. Sediment cores were processed for cladoceran remains and sedimentary pigments to determine community types that are vulnerable to invasion and the potential impact that D. lumholtzi may have on native communities. The paleolimnological study determined that lakes invaded by D. lumholtzi are characterized by lower species diversity and communities comprised of smaller sized zooplankton species. These results were supported in an experimental mesocosm study. A resource overlap study investigated the utilization of food resources by D. lumholtzi in comparison to native cladoceran species. This study concluded that there is minimum food resource overlap between D. lumholtzi and small bodied zooplankton species, while larger species consume larger particles and exhibit higher grazing rates than D. lumholtzi. Each of the investigations suggests that communities with larger sized species may inhibit the establishment of D. lumholtzi as a result of high resource overlap. Communities dominated by smaller species may be more susceptible to invasion as D. lumholtzi does not appear to be in direct competition with these species. Further, the elongated spines of (open full item for complete abstract)

Committee: Robert Carlson (Committee Chair); Mark Kershner (Committee Member); James Blank (Committee Member); Alison Smith (Committee Member) Subjects: Biology; Ecology; Environmental Science; Freshwater Ecology; Paleoecology

Master of Science (MS), Bowling Green State University, 2012, Biological Sciences

Copper sulfate (25.2% Cu by weight) has been extensively used to control nuisance algae in drinking water storage reservoirs; in upground reservoirs in northwest Ohio, CuSO4 application regimens vary from no application to 600 µg Cu/L/year. While CuSO4 is effective in suppressing algae, it also has documented toxicities to zooplankton and chironomids, which are food resources for stocked sport fish. Between May-August 2010, water, sediment, sediment trap, zooplankton, and macroinvertebrate samples were collected at four upground reservoirs with varying CuSO4 application regimens in order to track the fate of copper and enumerate zooplankton and macroinvertebrate community changes before and after CuSO4 application. Additionally, to quantify the combined effects of pulsed copper-laden food resources and contaminated sediment on chironomids of different instars, an experiment was conducted with Chironomus riparius in the laboratory. In the reservoirs, water copper concentration was 2-4 times higher post-application than before; correspondingly, zooplankton biomass and density were depressed by as much as 93% and 87% for at least one week after application. Furthermore, post-application zooplankton communities were dominated by copepod nauplii, which are an unsuitable food source for fish stocked into these reservoirs. Chironomid density changes appeared to reflect adult emergence rather than CuSO4 application, although standard sampling protocol prevented tracking all instars through time, so the effects of CuSO4 application on chironomid communities were not evident. The sedimentation rate of detritus and algae increased by 36% post-application and contained more than 5000 µg Cu/g dry weight. In the experiment, I found that organisms receiving a pulse of copper-laden algae in the first instar experienced 85% mortality, while organisms fed unspiked algae (controls) experienced 40% mortality. Field observations underscore the need for communication between reservoir ma (open full item for complete abstract)

Committee: Jeffrey G. Miner PhD (Advisor); John R. Farver PhD (Committee Member); Helen J. Michaels PhD (Committee Member); Joseph D. Conroy PhD (Committee Member) Subjects: Ecology; Entomology; Freshwater Ecology; Limnology; Toxicology