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Theses/Dissertations

Dissertations, Theses, and Masters Projects

Life Sciences

2010

Articles 1 - 14 of 14

Full-Text Articles in Physical Sciences and Mathematics

The Role Of Copepods And Heterotrophic Dinoflagellates In The Production Of Dissolved Organic Matter And Inorganic Nutrients, Grace Kathleen Saba Jan 2010

The Role Of Copepods And Heterotrophic Dinoflagellates In The Production Of Dissolved Organic Matter And Inorganic Nutrients, Grace Kathleen Saba

Dissertations, Theses, and Masters Projects

Zooplankton play a key role in the cycling of dissolved organic matter (DOM) and inorganic nutrients. The factors that affect these processes, however, are not fully understood. I measured the effects of various diets on DOM and inorganic nutrient production by the copepod Acartia tonsa and the heterotrophic dinoflagellate Oxyrrhis marina, and explored the mechanisms of nutrient release from copepods. Copepods feeding on a mixed diet, the preferred diet of most copepods, had significantly lower dissolved organic carbon (DOC), ammonium (NH4+), and total dissolved nitrogen (TDN) release rates compared to feeding on a carnivorous or herbivorous diet. Thus, copepod feeding …


Bioavailability Of Biosolids- And Consumer Product-Associated Polybrominated Diphenyl Ether (Pbde) Flame Retardants To Terrestrial Invertebrates, Michael O. Gaylor Jan 2010

Bioavailability Of Biosolids- And Consumer Product-Associated Polybrominated Diphenyl Ether (Pbde) Flame Retardants To Terrestrial Invertebrates, Michael O. Gaylor

Dissertations, Theses, and Masters Projects

The primary objectives of this research were therefore to evaluate polybrominated diphenyl ether (PBDE) bioavailability to ecologically distinct soil invertebrates exposed to Penta-BDE-treated consumer polyurethane foam (PUF) products and biosolid products with incurred PBDEs. In laboratory bioassays, earthworms (Eisenia fetida) bioaccumulated SigmaPBDEs (47+99+100+183) up to 11,000 mug/kg lipid after 28 days from a mixture of artificial soil and anaerobically-digested sludge biosolid (ADB). Earthworms also bioaccumulated SigmaPBDEs (47+99+100+153+154+183) up to 13,500 and 838,000 mug/kg lipid after 28 d from a mixture of artificial soil and composted sludge biosolid (CB) and Penta-BDE-spiked artificial soil (SAS), respectively. No previous lab studies on bioaccumulation …


Persistent Organic Pollutants(Pops) As Tracers Of Environmental Change And Antarctic Seabird Ecology, Heidi N. C. Geisz Jan 2010

Persistent Organic Pollutants(Pops) As Tracers Of Environmental Change And Antarctic Seabird Ecology, Heidi N. C. Geisz

Dissertations, Theses, and Masters Projects

Antarctic seabirds including Adelie penguins (Pygoscelis adeliae), south polar skuas (Catharacta maccormicki), southern giant petrels (Macronectes gigantus) are high trophic level predators that accumulate persistent organic pollutants (POPs) present in the food webs in which they forage. Little is known about the levels of POPs in some Antarctic organisms (e.g. southern giant petrels), as well as the long-term trends of POPs in the Antarctic ecosystem. Samples from all three seabird species were collected post mortem, including eggs, from the Western Antarctic Peninsula (WAP) and in the Ross Sea throughout the austral summer breeding seasons of 2004--2006. The samples were analyzed …


"You Have No Boss Here To Work For": Women And Labor In Chesapeake Bay Fishing Communities, Elizabeth Marie O'Grady Jan 2010

"You Have No Boss Here To Work For": Women And Labor In Chesapeake Bay Fishing Communities, Elizabeth Marie O'Grady

Dissertations, Theses, and Masters Projects

No abstract provided.


Assessing The Functional Status Of Created Wetlands In Eastern Virginia Via A Soil And Vegetative Developmental Trajectory, Sara Elizabeth Kreisel Jan 2010

Assessing The Functional Status Of Created Wetlands In Eastern Virginia Via A Soil And Vegetative Developmental Trajectory, Sara Elizabeth Kreisel

Dissertations, Theses, and Masters Projects

No abstract provided.


The Lateral Extent And Spatial Variation Of Mercury Exposure In Birds And Their Prey Near A Polluted River, Mikaela Gioia Selene Howie Jan 2010

The Lateral Extent And Spatial Variation Of Mercury Exposure In Birds And Their Prey Near A Polluted River, Mikaela Gioia Selene Howie

Dissertations, Theses, and Masters Projects

No abstract provided.


Effects Of Habitat Quality On Secondary Production In Shallow Estuarine Waters And The Consequences For The Benthic-Pelagic Food Web, David James Gillett Jan 2010

Effects Of Habitat Quality On Secondary Production In Shallow Estuarine Waters And The Consequences For The Benthic-Pelagic Food Web, David James Gillett

Dissertations, Theses, and Masters Projects

Anthropogenic degradation of coastal and estuarine habitats is an ongoing problem facing scientists, natural resource mangers, and the general public. Decreases in habitat quality produce relatively predictable changes in the structure and composition of macrobenthic communities and it has traditionally been assumed that the ecosystem functions of the community change as well. In Chesapeake Bay, the most pervasive cause for the degradation of benthic habitats is the excessive inputs of nutrients that lead to eutrophication and the accumulation of organic matter in the system. Working within this framework, a study was conducted investigating changes in macrobenthic (i.e., secondary) production along …


The Life History Of Longnose Gar, Lepisosteus Osseus, An Apex Predator In The Tidal Waters Of Virginia, Patrick E. Mcgrath Jan 2010

The Life History Of Longnose Gar, Lepisosteus Osseus, An Apex Predator In The Tidal Waters Of Virginia, Patrick E. Mcgrath

Dissertations, Theses, and Masters Projects

Longnose gar (Lepisosteus osseus) inhabit all of the major tributaries of Chesapeake Bay in Virginia, extending from fresh to estuarine waters. Literature concerning longnose gar from tidal environments is limited and this is study concerns important aspects of the life history (e.g., growth, reproduction, dimorphism, movements, and diet). Age, growth, and reproduction are important life history aspects for understanding the biology of fishes and may be affected by the environment in which an individual lives. This study found no differences in the age, growth, and fecundity parameters between longnose gar from tidal portions of Chesapeake Bay tributaries and previous studies …


Alternative Substrates As A Native Oyster (Crassostrea Virginica) Reef Restoration Strategy In Chesapeake Bay, Russell Paul Burke Jan 2010

Alternative Substrates As A Native Oyster (Crassostrea Virginica) Reef Restoration Strategy In Chesapeake Bay, Russell Paul Burke

Dissertations, Theses, and Masters Projects

Oyster shell for native oyster reef restoration is scarce in Chesapeake Bay and other estuaries (Chapter 1). Consequently, alternative substrates merit consideration in oyster restoration. This dissertation examines the suitability of shell alternatives, including granite, concrete, limestone marl, concrete modules and reefballs with reef surveys and experiments in the Rappahannock and Lynnhaven Rivers of Chesapeake Bay. Oyster recruitment, growth, survival, density, biomass, condition, and disease stress, as well as reef accretion and persistence, were measured. In the Lynnhaven River, intertidal riprap had a mean density of 978 oysters m-2 (165 g AFDM m-2) and peak densities > 2000 oysters m-2 (Chapter …


Quantifying The Ecosystem Role Of A Suspension And A Facultative Deposit Feeding Bivalve In The New River Estuary, Nc: With Responses To Changes In Nutrient And Sediment Inputs, Heather Marie Wiseman Jan 2010

Quantifying The Ecosystem Role Of A Suspension And A Facultative Deposit Feeding Bivalve In The New River Estuary, Nc: With Responses To Changes In Nutrient And Sediment Inputs, Heather Marie Wiseman

Dissertations, Theses, and Masters Projects

No abstract provided.


Survival In An Urbanized Landscape: Radio-Tracking Fledgling Eastern Bluebirds (Sialia Sialis) On Golf Courses, Allyson Kathleen Jackson Jan 2010

Survival In An Urbanized Landscape: Radio-Tracking Fledgling Eastern Bluebirds (Sialia Sialis) On Golf Courses, Allyson Kathleen Jackson

Dissertations, Theses, and Masters Projects

No abstract provided.


Habitat Complexity And Habitat Function Of Native (Crassostrea Virginica) And Non-Native (C. Ariakensis) Oysters In The Chesapeake Bay Region, Heather D. Harwell Jan 2010

Habitat Complexity And Habitat Function Of Native (Crassostrea Virginica) And Non-Native (C. Ariakensis) Oysters In The Chesapeake Bay Region, Heather D. Harwell

Dissertations, Theses, and Masters Projects

Complex oyster reefs created by the Eastern oyster, Crassostrea virginica, though once prominent features of the Chesapeake Bay region, have become relatively scarce in comparison to historic descriptions. This decline, caused by a combination of overfishing, disease, habitat destruction and pollution, this decline continues despite substantial restoration efforts that have spanned decades. In response to this decline, the states of Virginia and Maryland considered the intentional introduction of the non-native Suminoe oyster, C. ariakensis. Previous studies questioned the reef-building capability of this Crassostrea species, which may affect its habitat function. Through a combination of field and mesocosm studies, I examined …


Acoustics Of Anthropogenic Habitats: The Impact Of Noise Pollution On Eastern Bluebirds, Caitlin Rebecca Kight Jan 2010

Acoustics Of Anthropogenic Habitats: The Impact Of Noise Pollution On Eastern Bluebirds, Caitlin Rebecca Kight

Dissertations, Theses, and Masters Projects

An increasing number of habitats are affected by anthropogenic noise pollution, which is often louder, has a different frequency emphasis, and may occur over a different temporal scale, than natural noise. An increasing number of studies indicate that acoustically-communicating animals in such areas can modify their vocalizations in order to make themselves heard over the noise, but many questions still remain, including: How taxonomically widespread is vocal flexibility in response to anthropogenic noise, and do all vocally flexible species employ the same mechanisms to escape acoustic masking? Are there fitness repercussions for living, communicating, and breeding in noisy habitats? and, …


Copepod Carcasses, Mortality And Population Dynamics In The Tributaries Of The Lower Chesapeake Bay, David Thomas. Elliott Jan 2010

Copepod Carcasses, Mortality And Population Dynamics In The Tributaries Of The Lower Chesapeake Bay, David Thomas. Elliott

Dissertations, Theses, and Masters Projects

Several studies have documented the occurrence of substantial numbers of zooplankton carcasses in marine field samples. However, the potential effect of carcasses on conclusions resting on zooplankton abundance estimates, and the reasons for carcass occurrence have been largely disregarded. Many field studies do not account for the presence of carcasses in their sampling methodology. Zooplankton carcasses in situ are significant for several reasons. as concentrated particles of organic matter in the water column, zooplankton carcasses can be important vehicles for organic matter transport and hotspots of microbial abundance and activity. If dead animals are treated alive, carcasses could bias the …