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Environmental Sciences

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Dissertations, Theses, and Masters Projects

Theses/Dissertations

2009

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A Numerical Modeling Study On Barotropic And Baroclinic Responses Of The Chesapeake Bay To Hurricane Events, Kyoung-Ho Cho Jan 2009

A Numerical Modeling Study On Barotropic And Baroclinic Responses Of The Chesapeake Bay To Hurricane Events, Kyoung-Ho Cho

Dissertations, Theses, and Masters Projects

The barotropic and baroclinic responses of the Chesapeake Bay to forcings from two hurricanes were investigated by using unstructured-grid three-dimensional hydrodynamic models. The model domain includes Chesapeake Bay proper, the tributaries, and its extended continental shelf in the mid-Atlantic Bight. Two hurricanes were studied: Hurricane Floyd of September, 1999 and Hurricane Isabel of September, 2003, both of which made landfall within 100 km of the Chesapeake Bay mouth. Hurricane Floyd in 1999 passed through the entrance of the Bay from southwest to northeast along the coastlines of Virginia as a Category 1 storm, whereas Hurricane Isabel in 2003 made landfall …


Interactions Between Macroalgae And The Sediment Microbial Community: Nutrient Cycling Within Shallow Coastal Bays, Amber Kay Hardison Jan 2009

Interactions Between Macroalgae And The Sediment Microbial Community: Nutrient Cycling Within Shallow Coastal Bays, Amber Kay Hardison

Dissertations, Theses, and Masters Projects

Ephemeral macroalgal blooms are considered a symptom of eutrophication in shallow coastal lagoons, but their influence on nutrient cycling dynamics in these systems is not fully understood. From 2006-2008, I conducted a series of experiments to determine the influence of living and senescent macroalgae on sediment carbon (C) and nitrogen (N) cycling in coastal lagoons along the Delmarva Peninsula, USA. In particular, I focused on how macroalgae affect the microbial community at the sediment-water interface of shallow subtidal sediments because this complex consortium of autotrophic (e.g. benthic microalgae, BMA) and heterotrophic (e.g. bacteria) organisms plays a critical role in nutrient …


Polybrominated Diphenyl Ether Flame Retardants In Birds Of Prey From The U.S. And China, Da Chen Jan 2009

Polybrominated Diphenyl Ether Flame Retardants In Birds Of Prey From The U.S. And China, Da Chen

Dissertations, Theses, and Masters Projects

Polybrominated diphenyl ether (PBDE) flame retardants are widely used as non-reactive additives in textiles, polyurethane foams, plastics, furnishings, and electronic products. as a result of substantial, long-term usages, PBDEs have contaminated humans, wildlife, air, water, soil, and sediment, even in remote areas. Although the North American and Asian (particularly Chinese) markets have consumed the majority of global PBDE production, knowledge about PBDE contamination is limited in these two regions. Therefore, this research aimed to investigate PBDE contamination in some Chinese and North American areas by examining the birds of prey that have been considered as sensitive monitoring species for organochlorine …


Songbirds, Pesticides, And Golf Courses: Exposure And Effects, Ryan Brennan Burdge Jan 2009

Songbirds, Pesticides, And Golf Courses: Exposure And Effects, Ryan Brennan Burdge

Dissertations, Theses, and Masters Projects

No abstract provided.


Environmental Analysis Of Selected Estrogens And Androgens: Applying Ultra-Performance Liquid Chromatography And Combating Matrix Interference, Stacie L. Rice Jan 2009

Environmental Analysis Of Selected Estrogens And Androgens: Applying Ultra-Performance Liquid Chromatography And Combating Matrix Interference, Stacie L. Rice

Dissertations, Theses, and Masters Projects

Investigations of environmental hormone contamination commonly utilize solidphase extraction (SPE) followed by high-performance liquid chromatography / (electrospray ionization) tandem mass spectrometry (HPLC/(ESI)MS2) in the detection of estrogens. Matrix interference is widely reported. In this study, androgens were targeted alongside estrogens as environmentally co-introduced endocrine disrupting chemicals. Analytical methods were developed in parallel for detection of several hormones from each class, with comparison of protocols and instrumental parameters. Ultraperformance LC (UPLC®), an emerging technology advertised for reduced retention times, was used in place of HPLC for hormone separation. Applicability to diverse aqueous samples was tested. Matrix interference was combated with two …


Toxicology Of Decabromodiphenyl Ether In Avian Embryos: Disposition Of The Flame Retardant Bde-209 In Yolk-Injected Chicken Embryos (Gallus Gallus), Samantha D. Sifleet Jan 2009

Toxicology Of Decabromodiphenyl Ether In Avian Embryos: Disposition Of The Flame Retardant Bde-209 In Yolk-Injected Chicken Embryos (Gallus Gallus), Samantha D. Sifleet

Dissertations, Theses, and Masters Projects

Polybrominated diphenyl ethers (PBDEs) are flame retardant chemicals of toxicological concern present in humans, wildlife, and the environment. Deca-BDE is the highest production product due to historical use patterns and recent regulatory limitations on the other two commercial formulations (Penta-BDE and Octa-BDE) in the U.S and Europe. The EU banned Deca-BDE starting July 1, 2008. However, it remains in usage in North America and elsewhere in the world. BDE-209 is the dominant congener in all Deca- BDE commercial products. BDE-209 has been reported to under go metabolic debromination to lesser brominated and more toxic and bioaccumulative congeners. However, insufficient data …


Mortality Of Diamondback Terrapins In Blue Crab Traps: Population Changes And Conservation In Southeastern Virginia, Megan Ann Rook Jan 2009

Mortality Of Diamondback Terrapins In Blue Crab Traps: Population Changes And Conservation In Southeastern Virginia, Megan Ann Rook

Dissertations, Theses, and Masters Projects

No abstract provided.


Water Quality In Headwater Streams: A Test Of Best Management Practices, Jonathan Worth Holley Jan 2009

Water Quality In Headwater Streams: A Test Of Best Management Practices, Jonathan Worth Holley

Dissertations, Theses, and Masters Projects

No abstract provided.