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Articles 1 - 29 of 29

Full-Text Articles in Life Sciences

The Impact Of Marine Reserves On Exploited Species With Complex Life Histories: A Modeling Study Using The Caribbean Spiny Lobster In Exuma Sound, Bahamas, William T. Stockhausen Jan 2001

The Impact Of Marine Reserves On Exploited Species With Complex Life Histories: A Modeling Study Using The Caribbean Spiny Lobster In Exuma Sound, Bahamas, William T. Stockhausen

Dissertations, Theses, and Masters Projects

Most benthic invertebrates and reef-associated fish undergo a dispersive, planktonic larval stage prior to settlement and metamorphosis into the juvenile and adult stages. In some species, settlement may be decoupled from adult abundance at local spatial scales if hydrodynamic conditions or larval behavior do not promote local retention. Similarly, spatial variability in postsettlement mortality or secondary dispersal by juveniles and adults may decouple spatial patterns of adult abundance from those of settlement. as a consequence, spatial patterns of settlement and adult abundance may be functionally related in a complex fashion. Whether biotic/environmental factors control spatial patterns of abundance may ...


Spatial And Temporal Variation In Plant Communities Of Three Tidal Salt Marshes Along The York River, Virginia, Rosemary E. Laird Jan 2001

Spatial And Temporal Variation In Plant Communities Of Three Tidal Salt Marshes Along The York River, Virginia, Rosemary E. Laird

Dissertations, Theses, and Masters Projects

No abstract provided.


Age, Growth, And Mortality Of Atlantic Croaker, Micropogonias Undulatus, In The Chesapeake Bay Region, John R. Foster Jan 2001

Age, Growth, And Mortality Of Atlantic Croaker, Micropogonias Undulatus, In The Chesapeake Bay Region, John R. Foster

Dissertations, Theses, and Masters Projects

No abstract provided.


Morphological Variation Of Three Populations Of The Veined Rapa Whelk, Rapana Venosa, An Invasive Predatory Gastropod Species, Rebecca A. Green Jan 2001

Morphological Variation Of Three Populations Of The Veined Rapa Whelk, Rapana Venosa, An Invasive Predatory Gastropod Species, Rebecca A. Green

Dissertations, Theses, and Masters Projects

No abstract provided.


Spatial And Temporal Variability Of Physical And Biological Mixing In The York River Subestuary, Tara A. Kniskern Jan 2001

Spatial And Temporal Variability Of Physical And Biological Mixing In The York River Subestuary, Tara A. Kniskern

Dissertations, Theses, and Masters Projects

No abstract provided.


Vitellogenin -- A Biomarker Of Exposure To Environmental Estrogens For Mummichog (Fundulus Heteroclitus) From A Creosote-Contaminated Site?, Sara Mirabilio Jan 2001

Vitellogenin -- A Biomarker Of Exposure To Environmental Estrogens For Mummichog (Fundulus Heteroclitus) From A Creosote-Contaminated Site?, Sara Mirabilio

Dissertations, Theses, and Masters Projects

Vitellogenin (VTG) is widely used as a biomarker for environmental estrogens and reproductive disruption in fish. Vitellogenesis is the process by which yolk is formed. The endpoint is most sensitive in male fish where vitellogenesis is an abnormal process. Research examining effects of environmental mixtures of chemicals (e.g. creosote) on vitellogenesis is limited. This study examines plasma VTG expression in both male and female mummichog, Fundulus heteroclitus, collected from a creosote-contaminated site and two reference sites in lower Chesapeake Bay, USA, and in wild-caught male reference fish exposed in the laboratory to creosote-contaminated sediment. Further, this study uses tissue ...


Growth Patterns Of Three Species Of Catfish (Ictaluridae) From Three Virginia Tributaries Of The Chesapeake Bay, William J. Connelly Jan 2001

Growth Patterns Of Three Species Of Catfish (Ictaluridae) From Three Virginia Tributaries Of The Chesapeake Bay, William J. Connelly

Dissertations, Theses, and Masters Projects

No abstract provided.


Effects Of Light And Salinity Stress On Vallisneria Americana (Wild Celery), Gail T. French Jan 2001

Effects Of Light And Salinity Stress On Vallisneria Americana (Wild Celery), Gail T. French

Dissertations, Theses, and Masters Projects

No abstract provided.


Life History Attributes Of Mid-Atlantic Menidia Menidia (Pisces: Atherinidae) And A Comparison With Northern (Massachusetts) And Southern (South Carolina) Populations, Richard K. Holmquist Jan 2001

Life History Attributes Of Mid-Atlantic Menidia Menidia (Pisces: Atherinidae) And A Comparison With Northern (Massachusetts) And Southern (South Carolina) Populations, Richard K. Holmquist

Dissertations, Theses, and Masters Projects

No abstract provided.


Heat Shock Protein (Hsp70) Response In The Eastern Oyster, Crassostrea Virginica, Exposed To Various Contaminants (Pahs, Pcbs And Cadmium), Luis A. Cruz Rodriguez Jan 2001

Heat Shock Protein (Hsp70) Response In The Eastern Oyster, Crassostrea Virginica, Exposed To Various Contaminants (Pahs, Pcbs And Cadmium), Luis A. Cruz Rodriguez

Dissertations, Theses, and Masters Projects

The stress protein response has been proposed as a general indicator of exposure to stress as their expression might integrate overall biological impact and interactions among multiple stressors. as a marker of contaminant effects, a major advantage is the premise of higher sensitivity over other indices such as condition index, scope for growth and survival. Laboratory exposure to suspended field contaminated sediments (SFCS) elicited a stress protein response (HSP70) in the eastern oyster, ( Crassostrea virginica). The stress response probably resulted from the combined effect of various contaminants including PAHs, metals and PCBs. Exposure to 1--2g suspended clay particles spiked with ...


Persistent Organic Pollutant Transport And Fate: Assessment By Molecular Tracers, Padma T. Venkatraman Jan 2001

Persistent Organic Pollutant Transport And Fate: Assessment By Molecular Tracers, Padma T. Venkatraman

Dissertations, Theses, and Masters Projects

Persistent organic pollutants (POPs) such as the organochlorine pesticide hexachlorocyclohexane (HCH) may undergo atmospheric transport and accumulate in regions remote from the source. It is important to develop techniques to help apportion source and identify transport or transformation processes to which HCHs and other mobile POPs may be subjected. Molecular tracers such as compound specific stable isotope and enantiomer ratios (ERs) may prove valuable in studying POP fate and transport. The objective of this study was to further develop the use of these two novel geochemical tools to evaluate the sources, transport and environmental fate of POPs, in the context ...


Adrenal Expression Of Cyp17 And Hsd3b1 Mrna In Peromyscus Maniculatus Bairdii, Brian Thomas Lovitt Jan 2001

Adrenal Expression Of Cyp17 And Hsd3b1 Mrna In Peromyscus Maniculatus Bairdii, Brian Thomas Lovitt

Dissertations, Theses, and Masters Projects

No abstract provided.


Age-Related Differences In The Prey-Dropping Behavior Of Herring Gulls (Larus Argentatus), Eric G. Dunlavey Jan 2001

Age-Related Differences In The Prey-Dropping Behavior Of Herring Gulls (Larus Argentatus), Eric G. Dunlavey

Dissertations, Theses, and Masters Projects

No abstract provided.


Tr Phosphorylation & Nuclear Import, James B. Nicoll Jan 2001

Tr Phosphorylation & Nuclear Import, James B. Nicoll

Dissertations, Theses, and Masters Projects

No abstract provided.


Differential Migration, Molt And Departure Date In White-Throated Sparrows, Zonotrichia Albicollis, Kendell Jenkins Jan 2001

Differential Migration, Molt And Departure Date In White-Throated Sparrows, Zonotrichia Albicollis, Kendell Jenkins

Dissertations, Theses, and Masters Projects

No abstract provided.


Allozyme Variation In American Ginseng, Panax Quinquefolius L (Araliaceae): Implications For Management Of Wild And Cultivated Populations, Holly Jean Grubbs Jan 2001

Allozyme Variation In American Ginseng, Panax Quinquefolius L (Araliaceae): Implications For Management Of Wild And Cultivated Populations, Holly Jean Grubbs

Dissertations, Theses, and Masters Projects

No abstract provided.


The Energetics Of Seasonal Reproductive Inhibition In White-Footed Mice, Michelle E. Rightler Jan 2001

The Energetics Of Seasonal Reproductive Inhibition In White-Footed Mice, Michelle E. Rightler

Dissertations, Theses, and Masters Projects

No abstract provided.


Beyond Ability: Effects Of Caffeine And Impulsivity On Academic And Creative Performance, Sara E. Chambers Jan 2001

Beyond Ability: Effects Of Caffeine And Impulsivity On Academic And Creative Performance, Sara E. Chambers

Dissertations, Theses, and Masters Projects

No abstract provided.


Genetic Investigation Of Interspecific And Intraspecific Relationships Within The Genus Rapana, Arminda L. Gensler Jan 2001

Genetic Investigation Of Interspecific And Intraspecific Relationships Within The Genus Rapana, Arminda L. Gensler

Dissertations, Theses, and Masters Projects

No abstract provided.


Use Of Pop-Up Satellite Tag Technology To Estimate Survival Of Blue Marlin (Makaira Nigricans) Released From Pelagic Longline Gear, David Kerstetter Jan 2001

Use Of Pop-Up Satellite Tag Technology To Estimate Survival Of Blue Marlin (Makaira Nigricans) Released From Pelagic Longline Gear, David Kerstetter

Dissertations, Theses, and Masters Projects

No abstract provided.


A Descriptive Study Of The Reproductive Biology Of The Veined Rapa Whelk (Rapana Venosa) In The Chesapeake Bay, Erica S. Westcott Jan 2001

A Descriptive Study Of The Reproductive Biology Of The Veined Rapa Whelk (Rapana Venosa) In The Chesapeake Bay, Erica S. Westcott

Dissertations, Theses, and Masters Projects

No abstract provided.


Reproductive Biology Of Atlantic Croaker, Micropogonias Undulatus, In The Chesapeake Bay, Elizabeth Shaw Watkins Jan 2001

Reproductive Biology Of Atlantic Croaker, Micropogonias Undulatus, In The Chesapeake Bay, Elizabeth Shaw Watkins

Dissertations, Theses, and Masters Projects

No abstract provided.


Assessment Of Development Impacts On Coastal Zone: Integrated Approach, Northampton County, Eastern Shore, Virginia, Sarunas Zableckis Jan 2001

Assessment Of Development Impacts On Coastal Zone: Integrated Approach, Northampton County, Eastern Shore, Virginia, Sarunas Zableckis

Dissertations, Theses, and Masters Projects

No abstract provided.


Evaluation Of Opercular Bones For Aging Eight Species Of Chesapeake Bay Fishes, Ann M. Sipe Jan 2001

Evaluation Of Opercular Bones For Aging Eight Species Of Chesapeake Bay Fishes, Ann M. Sipe

Dissertations, Theses, and Masters Projects

No abstract provided.


Application Of The Genetic Algorithm To An Ecological Simulation, William J. Seufzer Jan 2001

Application Of The Genetic Algorithm To An Ecological Simulation, William J. Seufzer

Dissertations, Theses, and Masters Projects

A computational framework is built and demonstrated which is capable of testing plant growth strategies. The framework consists of Vgrass, a carbon based simulation model of a single Zostera marina plant, and the genetic algorithm (GA). Vgrass is based on published seagrass models, published photosynthetic data, and general plant physiology information. The model grows individual leaves whose initiation times are based on degree-day intervals. Leaf size is computed and combined with shoot density to compute population self shading. Leaf length is an emergent property since leaf growth is limited by light attenuation caused by self shading. The model is able ...


New Dimensionless Indices Of Structural Habitat Complexity, Aaron Bartholomew Jan 2001

New Dimensionless Indices Of Structural Habitat Complexity, Aaron Bartholomew

Dissertations, Theses, and Masters Projects

Ecologists have long known that complex habitats often provide prey with refugia from predation in a wide variety of habitat types and for a wide variety of prey species. Despite the recognized importance of structural habitat complexity, ecologists have measured complexity in many different ways. I propose four new indices of structural habitat complexity that are dimensionless, that can be applied across various habitat types and scales, and that directly measure how structural complexity interferes with a predator's foraging ability. These indices are: (1) Ct/At, the total area of cover within a habitat (Ct) divided by the area ...


Molecular Characterization Of Cultured Perkinsus Marinus Isolates, Gwynne D. Brown Jan 2001

Molecular Characterization Of Cultured Perkinsus Marinus Isolates, Gwynne D. Brown

Dissertations, Theses, and Masters Projects

Perkinsus marinus is the causative agent of the oyster disease Dermo in the eastern oyster, Crassostrea virginica. In vitro propagation of the parasite has led to the establishment of multiple isolates by several investigators. Little work, however, has been done to characterize different isolates. In this study multiple isolates were examined for genetic and biochemical diversity. at two loci, the ITS region and the ATAN region, there was as much intra-isolate genetic variation among DNA sequences of some isolates as there was inter-isolate variation. Variation was also observed at a third loci, a subtilisin-like serine protease gene. This is the ...


Nursery Delineation, Habitat Utilization, Movements, And Migration Of Juvenile Carcharhinus Plumbeus In Chesapeake Bay, Virginia, United States Of America, R. Dean. Grubbs Jan 2001

Nursery Delineation, Habitat Utilization, Movements, And Migration Of Juvenile Carcharhinus Plumbeus In Chesapeake Bay, Virginia, United States Of America, R. Dean. Grubbs

Dissertations, Theses, and Masters Projects

Chesapeake Bay is possibly the largest summer nursery for Carcharhinus plumbeus in the western Atlantic. Longline sampling conducted from 1990--1999 was used to delineate this nursery spatially and temporally. Catch data from 83 longline stations sampled throughout the Virginia Chesapeake Bay were analyzed as a function of nine physical and environmental variables to delineate this nursery spatially. Tree-based models determined which variables best discriminated between stations with high and low catches and indicated that complex distribution patterns could be adequately modeled with few variables. The highest abundance of juvenile sharks was predicted where salinity was greater than 20.5 and ...


Effects Of Humic Acids And Salinity On Pesticide Bioavailability And Toxicity As Estimated By Spme And Toxicity Tests, Laurent C. Mézin Jan 2001

Effects Of Humic Acids And Salinity On Pesticide Bioavailability And Toxicity As Estimated By Spme And Toxicity Tests, Laurent C. Mézin

Dissertations, Theses, and Masters Projects

The interactive effects of humic acids (HAs) and salinity on the bioavailability and toxicity of the pesticides chlorpyrifos and 4,4'-dichlorodiphenyltrichloroethane (DDT) were investigated. The effects of various HAs on the toxicity of chlorpyrifos were initially assessed with the chronic MicrotoxRTM test. Environmentally relevant concentrations of Aldrich, Peat, Leonardite and Suwannee River HAs had no significant effect on the toxicity of either chlorpyrifos or copper (Cu), the test's positive control. as reductions in contaminant toxicity had previously been reported for some contaminants by HAs, it appeared that salinity might be a mitigating factor. Thus salinity effects were further ...