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Molecular Phylogeny Of Lake Baikal Amphipods, Kenneth S. Macdonald
Molecular Phylogeny Of Lake Baikal Amphipods, Kenneth S. Macdonald
Dissertations, Theses, and Masters Projects
No abstract provided.
Environmental Stress In Hard Coral: Evaluating Lipid As An Indicator Of Sublethal Stress On Short Time Scales, David Harold Niebuhr
Environmental Stress In Hard Coral: Evaluating Lipid As An Indicator Of Sublethal Stress On Short Time Scales, David Harold Niebuhr
Dissertations, Theses, and Masters Projects
Lipid quality was evaluated in Montastrea spp. under sediment- and heat-stressed conditions to evaluate lipid ratio as an indicator of sub-lethal stress on short time scales. The ratio of storage lipid (wax ester + triacylglyceride) to structural lipid (sterol esters + phospholipid) decreased significantly (0.25 to 0.14, p < 0.01) after experimental sedimentation. FAME analysis of colonies exposed to experimental sedimentation showed a reduction of the algal, 18:3(n-6) and 18:4(n-3), polyunsaturated fatty acid (PUFA) in the polar lipid fraction. This loss of PUFA suggests a loss of algal membrane in sediment-stressed colonies. Lipid quality was similarly measured in M. faveolata over a 10-day period. Mean (n = 20) ratio of storage to structural lipid in M. faveolata dropped from 2.43 to a level of 0.98 immediately following a natural sedimentation event before recovering to levels of 1.4 and 2.9 on post-storm days 2 and 4, respectively. Colonies of M. annularis subject to heat-stress (35??C) exhibited no significant change in storage lipid ratio, while levels of Free Fatty Acids increased significantly from 0.012 (n = 22) to 0.156 mg lipid/g dry tissue (n = 22)(p < 0.05). FAME analysis of tissue lipids extracted from the heat-stressed colonies showed changes in the polar fraction, with significant decreases in the 18:3(n-6), 18:3(n-3), 18:4(n-3), 20:4(n-6) and 20:5(n-3) (p < 0.05) PUFA and subsequent significant increases in the saturated fatty acids, 16:0 and 18:0 (p < 0.05). These changes in lipid quantity and quality indicate possible oxidation and preferential digestion of zooxanthellar membranes. Stress experiments were repeated in M. annularis using VacutainerRTM blood collection tubes to collect micro-tissue samples without destroying skeleton of the sample colonies. A significant decrease in storage: structural lipid ratio after sedimentation was also detected using the micro-tissue technique. This study indicates that the relative abundance of lipid subclass components can indicate sub-lethal environmental stress, on short time scales, in M. annularis and M. faveolata. Furthermore, micro-tissue collection techniques permit repeated monitoring coral colonies to assess the manifestation of stress from first detection of impact at the cellular level to changes in community to changes in community structure detectable over longer time scales.
Nitrate Reduction At The Groundwater - Salt Marsh Interface, Craig -1967 Tobias
Nitrate Reduction At The Groundwater - Salt Marsh Interface, Craig -1967 Tobias
Dissertations, Theses, and Masters Projects
The influence of groundwater discharge on the hydrology and biogeochemical cycling of nitrogen in a fringing intertidal wetland was studied by characterizing groundwater discharge, determining N-cycling rates in cores, and examining nitrate reduction in situ using 15N enrichment and natural gradient tracer techniques. Groundwater discharge was estimated by three independent methods: Darcy's Law, a water/salt mass balance, and a subsurface tracer test. Seasonal patterns of discharge predicted by Darcy's Law and the mass balance were similar. Discharge maxima and minima occurred in April and September, respectively. The water/salt mass balance provided the more reasonable estimate of groundwater flux at high …
Limitation Of Bacterial Growth By Dissolved Organic Matter And Iron In The Southern Ocean, Matthew J. Church
Limitation Of Bacterial Growth By Dissolved Organic Matter And Iron In The Southern Ocean, Matthew J. Church
Dissertations, Theses, and Masters Projects
No abstract provided.
Habitat Fragmentation In Transplanted Eelgrass (Zostera Marina) Beds: Effects On Decapods And Fish, Alfonso Vollmer Lombana
Habitat Fragmentation In Transplanted Eelgrass (Zostera Marina) Beds: Effects On Decapods And Fish, Alfonso Vollmer Lombana
Dissertations, Theses, and Masters Projects
No abstract provided.
A Comparison Of Size Selectivity And Relative Efficiency Of Sea Scallop Trawls And Dredges, David B. Rudders
A Comparison Of Size Selectivity And Relative Efficiency Of Sea Scallop Trawls And Dredges, David B. Rudders
Dissertations, Theses, and Masters Projects
No abstract provided.
Tidally Driven Patterns Of Nekton Distribution And Utilization Of A Tidal Freshwater Marsh At Morris Creek (Chickahominy River, Virginia), Eric Anthony Wooden
Tidally Driven Patterns Of Nekton Distribution And Utilization Of A Tidal Freshwater Marsh At Morris Creek (Chickahominy River, Virginia), Eric Anthony Wooden
Dissertations, Theses, and Masters Projects
No abstract provided.
Artificial Societies: A Computational Approach To Studying Combat, Rachel J. Moore
Artificial Societies: A Computational Approach To Studying Combat, Rachel J. Moore
Dissertations, Theses, and Masters Projects
No abstract provided.
Analysis Of Mercury Coordination Environments Of Tridentate And Tetradentate Imidazole Based Ligands By X-Ray Crystallography And Nmr Spectroscopy, Geoffrey Murphy
Analysis Of Mercury Coordination Environments Of Tridentate And Tetradentate Imidazole Based Ligands By X-Ray Crystallography And Nmr Spectroscopy, Geoffrey Murphy
Dissertations, Theses, and Masters Projects
No abstract provided.