Pharmacology, Toxicology and Environmental Health Commons^™

Cytotoxicity And Reproductive Impairment In Rainbow Trout Cell Lines Exposed To Microcystis Aeruginosa Extracellular Metabolites, Keira Harshaw

Electronic Theses and Dissertations

Current trends in cyanobacterial harmful algal blooms (cHABs) demonstrate increasing risks to human health and the health of aquatic ecosystems around the globe. Expansion of algal blooms, both geographically and temporally, serve to place increasing numbers of freshwater species, including fish, in peril. Microcystis aeruginosa, one of the most common species of bloom-causing cyanobacteria, is capable of producing a vast diversity of biologically active compounds, however Microcystis studies are often dominated by microcystins. How non-microcystin metabolites contribute to Microcystis toxicity, particularly in freshwater fish, has been the subject of a limited, but growing, body of research. To contribute to …

Coastal Stormwater Pond Pollutants And The Potential For Development Of Antimicrobial Resistance In Vibrio And Enterococcus Bacteria, Cassandra L. Horton

Theses and Dissertations

The Southeastern coastal plain is the most rapidly urbanizing region in the United States. Associated landscape changes which increase imperviousness lead to hydrological cycle alterations, increasing runoff of nonpoint source (NPS) pollution. Urban and agricultural NPS runoff is generally discharged into stormwater ponds, which sequester chemical contaminants, nutrients, and microbes to reduce loading into coastal ecosystems. Studies of these ponds have indicated elevated levels of trace metals, antimicrobial compounds, and bacterial contamination (SCSGC 2018).

Interactions of aquatic pathogens Vibrio vulnificus and Enterococcus faecium with trace metals (arsenic, copper, zinc) and clinically relevant antimicrobials (triclosan, ciprofloxacin, oxytetracycline) commonly found in coastal …

Molecular And Behavioral Impacts Of Treated Wastewater Effluent On Fish, Peter Schumann

Theses and Dissertations

Currently, most studies that focus on the sublethal impacts of contaminants of emerging concern (CECs) such as pharmaceuticals utilize a single-compound approach, whereas these compounds always occur as complex mixtures in the environment. Wastewater treatment plants (WWTPs) are a major contributor to the formation of these mixtures as current treatment technologies inadequately remove many chemical pollutants. There is a paucity of knowledge on the neurological impacts due to exposure to complex CEC mixtures resulting from the discharge of treated WWTP effluent into aquatic environments. This knowledge gap leaves incomplete assessments of the hazards and risks from exposure to treated effluent …

The Effect Of Seasonality On Yellow Perch Ecology And Ecotoxicology Within Lake Manganese, Bailey Duxbury

Dissertations, Master's Theses and Master's Reports

Seasonality is a consistent component of aquatic ecosystems yet most fish biological and ecotoxicological studies commonly employ field sampling protocols focused during the warm open water season with minimal emphasis placed on winter sampling, especially for north-temperate latitude ecosystems. Such strategies limit our understanding of poikilotherm biology and ecology during the overwintering seasons. Here, I investigated seasonal changes in yellow perch (Perca flavescens) biology, ecology and ecotoxicology over a one-year period in Lake Manganese. Significant seasonality was observed for metrics including fish energy densities (kJ/g), gonadosomatic indices, whole-body lipid contents, and carbon stable isotope values (δ¹³C). …

Molecular Responses To Deepwater Horizon Oil Spill Contaminants In Estuarine Fish, Elizabeth Jones

Dissertations

The 2010 Deepwater Horizon (DWH) oil spill resulted in the oiling of approximately 2100 km of shoreline. During that time, resident organisms had to contend with the effects of multiple contaminants and suboptimal environmental conditions. This research examines the molecular effects of DWH oil spill contaminants in estuarine fish (CyprinodonvariegatusandFundulusgrandis) across multiple life stages, contaminant concentrations, and in conjunction with environmental stressors.

Our results indicate that:

1. Oil elicits substantial transcriptional effects across life stages in C. variegatus. In adults, exposure to low concentrations of oil and dispersant results in transcriptional effects related …

Macrophytes And Atrazine In Ponds Of Southwest Missouri, Christine Michelle Cornish

MSU Graduate Theses

Wetlands are often the ultimate destination of agrochemicals. The increased use of these pollutants has resulted in their increased transport, via runoff and spray drift, into wetlands. Atrazine, a commonly used herbicide, has been detected in surface water, groundwater, soil, and sediment, and has shown to have adverse impacts on aquatic biota, such as fish and amphibians. Few studies have reported on the relationships between atrazine and macrophytes. I measured atrazine concentrations in surface sediments in agricultural, conservation, and golf course ponds of southwest Missouri, and investigated how those concentrations might be related to macrophyte communities, and pond environmental characteristics. …

Characterizing The Impacts Of Contaminants On Fish Embryogenesis And Revealing An Alternate Molecular Mechanism Of Ahr Mediated Cardiac Defects, Corinna Singleman

Dissertations, Theses, and Capstone Projects

There is a long history of damage to natural ecosystems from environmental pollution. Many environmental contaminants are man-made and have been released with abandon over the last 100 years including dioxins, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), and polychlorinated biphenyls (PCBs). These chemicals act on similar cellular processes and cause skin lesions, cancer, learning disabilities and reproductive problems in many vertebrates. There are many studies exploring various aspects of TCDD and PCB exposure on model and wild organisms. Few studies however, have compared effects of PCB mixtures on ecosystems to effects of individual PCBs in the lab. The first aim of this thesis is …

Development Of A Dreissena Bioassay To Assess The Toxicity Of Contaminants Across Two Life-History Stages, Caroline Joyce Addis

Wayne State University Theses

Dreissenid mussels (Dreissena polymorpha and D. bugensis) have rapidly become widespread and ubiquitous in North America since their introduction into the Great Lakes in the 1980s. The resulting environmental and economic impacts of their invasion have been extensive, negatively affecting biodiversity and costing millions of dollars in control efforts and damage to power generation and water treatment facilities. Although dreissenids are often associated with negative impacts, they may present a practical tool for toxicology studies. The typically sessile behavior of the benthic adults coupled with the planktonic nature of the veligers allow for a more complete evaluation of water quality …

The Role Of Surface Chemistry In The Toxicity Of Manufactured Cerium Dioxide Nanomaterials To Caenorhabditis Elegans, Emily Kay Oostveen

Theses and Dissertations--Plant and Soil Sciences

Manufactured CeO₂ nanomaterials (CeO₂-MNMs) are used for a wide variety of applications including diesel fuel additives and chemical/mechanical planarization media. To test the effects of CeO₂-MNM surface coating charge on to model organism Caenorhabditis elegans, we synthesized 4 nm CeO₂ with cationic (DEAE-), anionic (CM-), and neutral (DEX) coatings. In L3 nematodes exposed for 24 hours, DEAE-CeO₂ induced lethality at lower concentrations than CM- or DEX-CeO₂. Feeding slightly decreased CeO₂ toxicity, regardless of coating. In L2 nematodes exposed for 48 hours with feeding, DEAE-CeO₂ caused lethality at the …