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Full-Text Articles in Life Sciences
Recruitment And Growth Of Juvenile Crassostrea Virginica (Gmelin) In Relation To Tidal Zonation, George Curtis Roegner
Recruitment And Growth Of Juvenile Crassostrea Virginica (Gmelin) In Relation To Tidal Zonation, George Curtis Roegner
Dissertations, Theses, and Masters Projects
No abstract provided.
Heterotrophic Bacterial Production: Relationships To Biological And Abiological Factors In Estuarine Environments, Eric Thor Koepfler
Heterotrophic Bacterial Production: Relationships To Biological And Abiological Factors In Estuarine Environments, Eric Thor Koepfler
Dissertations, Theses, and Masters Projects
Section 1. Ecotoxicological effects of creosote contamination on benthic bacterial communities in the Elizabeth River, Virginia were investigated using both structural and functional microbial parameters. Results indicated that cell specific and total heterotrophic bacterial production parameters were depressed in a dose dependent manner with increasing sediment PAH concentrations. Toxicity effects upon production were modified by temporal trends associated with temperature as well as spatial sediment characteristics. of the parameters employed, the tritiated thymidine production assay was found to be the most sensitive for detection of ecotoxicological effects. Section 2. Bacterial abundance and production were examined during a destratification event in …
Pcb Congener Analysis With Hall Electrolytic Conductivity Detection, Robert D. Edstrom
Pcb Congener Analysis With Hall Electrolytic Conductivity Detection, Robert D. Edstrom
Dissertations, Theses, and Masters Projects
This work reports the development of an analytical methodology for the analysis of PCB congeners based on integrating relative retention data provided by other researchers. The retention data were transposed into a multiple retention marker system which provided good precision in the calculation of relative retention indices for PCB congener analysis. Analytical run times for the developed methodology were approximately one hour using a commercially available GC capillary column. A Tracor Model 700A Hall Electrolytic Conductivity Detector (HECD) was employed in the GC detection of Aroclor standards and environmental samples. Responses by the HECD provided good sensitivity and were reasonably …
Uptake Kinetics And Toxicity Of Diazinon In The American Oyster, Crassostrea Virginica Gmelin, Ruth L. Williams
Uptake Kinetics And Toxicity Of Diazinon In The American Oyster, Crassostrea Virginica Gmelin, Ruth L. Williams
Dissertations, Theses, and Masters Projects
Several aspects of effects of the organophosphate pesticide diazinon on the American oyster Crassostrea virginica Gmelin were investigated. Uptake of diazinon directly from water was compared with uptake of diazinon sorbed to either fine sediment or algae; the primary route of assimilation seems to be from the water. Concentrations of diazinon between 0.91 and 2.03 mg/L inhibit shell growth during 96 hours of exposure; there is a sharp threshold of effect for this response which is probably an indirect one caused by lack of food during shell closure. Acetylcholinesterase inhibition is significant in oyster heart tissue at concentrations of approximately …
The Influence Of Tributyltin On Various Aspects Of Activation And Reactive Oxygen Formation In Oyster Toadfish (Opsanus Tau) Macrophages, Charles D. Rice
The Influence Of Tributyltin On Various Aspects Of Activation And Reactive Oxygen Formation In Oyster Toadfish (Opsanus Tau) Macrophages, Charles D. Rice
Dissertations, Theses, and Masters Projects
The effects of tributyltin (TBT) on phorbol myristate acetate (PMA)- and calcium ionophore (A23187)-stimulated peritoneal macrophages from oyster toadfish (Opsanus tau) were evaluated in a luminol-dependent chemiluminescence (CL) assay. PMA-stimulated CL responses were increased by in vitro exposure to 50 ug/L TBT, but depressed to baseline values by 500 ug/L TBT. A23187-stimulated CL increased with 5 ug/L and 50 ug/L TBT, and depressed by 500 ug/L TBT. Responses stimulated by synergistic doses of PMA and A23187 were increased by 50 ug/L TBT and depressed by 500 ug/L TBT. Enhanced PMA- and A23187-stimulated CL following TBT exposure returned to baseline values …
The Influence Of Salinity On The Swimming Behavior Of Larval Crassostrea Virginica (Gmelin), Kevin J. Mccarthy
The Influence Of Salinity On The Swimming Behavior Of Larval Crassostrea Virginica (Gmelin), Kevin J. Mccarthy
Dissertations, Theses, and Masters Projects
No abstract provided.
Nitrogen And Phosphorus Cycling Strategies In Two Tidal Freshwater Macrophytes, Peltandra Virginica And Spartina Cynosuroides, Paul Milton. Booth Jr
Nitrogen And Phosphorus Cycling Strategies In Two Tidal Freshwater Macrophytes, Peltandra Virginica And Spartina Cynosuroides, Paul Milton. Booth Jr
Dissertations, Theses, and Masters Projects
Monotypic stands of the macrophytes Peltandra virginica and Spartina cynosuroides, which shared a common boundary, were studied at Sweethall Marsh, a tidal freshwater marsh located on the Pamunkey River within the Chesapeake Bay estuarine system, Virginia. Compartmental models indicate that both Peltandra and Spartina take up, internally cycle, and release to the environment, significant levels of nitrogen and phosphorus. Models also suggest that Peltandra and Spartina and their associated sediment compartments are capable of regulating nitrogen and phosphorus fluxes through their uptake and storage capacity. Nitrogen use efficiency was significantly higher in the shoots and roots of Spartina compared to …
Effect Of Nitrogen And Phosphorus Enrichment On Lipid And Fatty Acid Composition Of Estuarine Microplankton, Jia Chen
Dissertations, Theses, and Masters Projects
No abstract provided.
Virginia's Pelagic Recreational Fishery: Biological, Socioeconomic And Fishery Components, Eleanor A. Bochenek
Virginia's Pelagic Recreational Fishery: Biological, Socioeconomic And Fishery Components, Eleanor A. Bochenek
Dissertations, Theses, and Masters Projects
Catch, effort, fleet size and boat owner expenditure data were collected on Virginia's recreational marlin/tuna fishery for the 1983-1985 seasons. Logbooks, dockside interviews and a telephone survey were evaluated to determine which method was the most efficient and effective for collecting and estimating catch and effort for Virginia's pelagic recreational fishery. In 1984, logbooks were used to collect catch and effort data and fishing effort was estimated using Bochenek's method. Very few fishermen returned their logbooks and as a result this data is probably less reliable than the data collected in other years. Due to the poor return of logbooks, …
Aspects Of Volume Regulation In Two Estuarine Invertebrates: Glycera Dibranchiata (Annelida) And Modiolus Demissus (Mollusca), Ana Marie Beardsley
Aspects Of Volume Regulation In Two Estuarine Invertebrates: Glycera Dibranchiata (Annelida) And Modiolus Demissus (Mollusca), Ana Marie Beardsley
Dissertations, Theses, and Masters Projects
No abstract provided.