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- Equatorial Pacific (2)
- Marine (2)
- Pacific Ocean (2)
- Phytoplankton (2)
- Virginia (2)
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- Benthic infaunal macroinvertebrate communities (1)
- Bio-optical (1)
- Copper-complexing (1)
- Data assimilative (1)
- El Nino (1)
- Gulf of Mexico (1)
- Hog Island Bay (1)
- Iodine (1)
- Ligands (1)
- Metallothioneins (1)
- Mixed layer model (1)
- Nitrate (1)
- Normal mode analysis (1)
- Nutrient loading (1)
- Ocean surface (1)
- Sea-side estuary (1)
- Surface maps (1)
- Synechococcus (1)
Articles 1 - 7 of 7
Full-Text Articles in Physical Sciences and Mathematics
Nitrate Reductase Activity, Nitrate Uptake And Iodine Speciation In The Marine Environment, Chin-Chang Hung
Nitrate Reductase Activity, Nitrate Uptake And Iodine Speciation In The Marine Environment, Chin-Chang Hung
OES Theses and Dissertations
The present method for the determination of new production (NP) by measuring the uptake of added 15NO3– suffers from a number of limitations. In an attempt to improve this situation, this research examined the possibility of estimating 15NO3– uptake by measuring the activity of nitrate reductase (NRA). In addition, because it has long been suspected that the biological reduction of IO3– to I– may be mediated by nitrate reductase (NR), this research investigated the ability of NR to catalyze the reduction of iodate to iodide.
An improved method for the determination …
Benthic Community Analysis Of Hog Island Bay, Virginia, David James Lewis
Benthic Community Analysis Of Hog Island Bay, Virginia, David James Lewis
Biological Sciences Theses & Dissertations
The benthic infaunal macroinvertebrate communities of Hog Island Bay of the Virginia Eastern Shore were quantitatively sampled at 30 locations on August 31 and September 1, 1995. The primary objectives of this study were: (1) to characterize the subtidal macroinfaunal benthic communities of Hog Island Bay, (2) to examine relationships between abiotic factors and the macroinfaunal communities and (3) to characterize the environmental condition of the system using the Benthic Index of Biotic Integrity (B-IBI) (Weisburg et al. 1997) and the EMAP Benthic Index for the Virginian Province (Strobel et al. 1995).
The ecological condition of Hog Island Bay appears …
Production Of Copper-Complexing Ligands In Response To Elevated Concentrations Of Copper In Marine Synechococcus Spp., Arunsri Chatkaeomorakot Brown
Production Of Copper-Complexing Ligands In Response To Elevated Concentrations Of Copper In Marine Synechococcus Spp., Arunsri Chatkaeomorakot Brown
Theses and Dissertations in Biomedical Sciences
Synechococcus spp. (marine cyanobacteria) are extremely sensitive to copper toxicity and can produce high-affinity ligands of unknown structure which form complexes with free cupric ion. These ligands may contribute to the biological control of the levels of free cupric ions in surface seawater. Synechococcus spp. are known to produce metallothioneins (MT) in response to cadmium and zinc stress. In the present study the hypothesis that marine Synechococcus produce MT in response to copper was tested. Three marine Synechococcus spp. i.e., PCC 7001, PCC 73109, and PCC 7003, were exposed to different concentrations of CUSO 4 for various time periods. Size …
Physical Control Of Biological Processes In The Central Equatorial Pacific: A Data Assimilative Modeling Study, Marjorie Anne Macwhorter Friedrichs
Physical Control Of Biological Processes In The Central Equatorial Pacific: A Data Assimilative Modeling Study, Marjorie Anne Macwhorter Friedrichs
OES Theses and Dissertations
A five-component data assimilative ecosystem model is developed in order to investigate the effects of physical processes encompassing a wide range of space and time scales, on the lower trophic levels of the highly dynamic central equatorial Pacific (140°W). Many of the biological processes included in the ecosystem model respond to environmental fluctuations with time scales between one and ten days, which are not typically resolved by basin to global scale circulation models. Therefore, the ecosystem model is forced using daily observations from the TAO mooring array. Model simulations successfully reproduce data collected both during and after the 1991–92 El …
The Impacts Of External Nutrient Sources On Marine Phytoplankton In An Eastern Shore Sea-Side Estuary, Claudette Lajoie Jenkins
The Impacts Of External Nutrient Sources On Marine Phytoplankton In An Eastern Shore Sea-Side Estuary, Claudette Lajoie Jenkins
OES Theses and Dissertations
The Eastern Shore of Virginia (Greens Creek) as well as a large portion of the North Atlantic coastline is characterized by estuarine systems not dominated by large river systems. Instead, small freshwater creeks influence many coastal systems yet little information has been documented on their ecological significance. The focus of this research is to identify the biogeochemical and physical interactions within an estuarine water-column and understand the importance of freshwater sources in governing phytoplankton production. The hypothesis of this research is that increases in external nutrient loading into Greens Creek will not result in an increase in primary production. The …
Ocean Surface Maps From Blending Disparate Data Through Normal Mode Analysis, William John Schulz Jr.
Ocean Surface Maps From Blending Disparate Data Through Normal Mode Analysis, William John Schulz Jr.
OES Theses and Dissertations
Rapid environmental assessment is conducted using disparate data sources in the northwestern Gulf of Mexico. An overview of significant physical features in the Gulf highlights the complexities of the large and meso-scale circulations. Spectral analysis of high resolution current meter and drifter data reveals the significant forcing features detectable by readily available observing techniques. These observations are combined with boundary data extracted from the U.S. Navy's Modular Ocean Data Assimilation System (MODAS) through Normal Mode Analysis (NMA). The NMA blending process is described, and surface maps of velocity and convergence are produced. Using statistical and qualitative techniques, the NMA generated …
A Coupled Bio-Optical And Mixed Layer Model For The Equatorial Pacific, James Vincent Koziana
A Coupled Bio-Optical And Mixed Layer Model For The Equatorial Pacific, James Vincent Koziana
OES Theses and Dissertations
A one dimensional coupled bio-optical and mixed layer model is developed and applied to problems involving the role of phytoplankton-induced turbidity (PIT) on the vertical structure and heating of the upper ocean in the Equatorial Pacific Ocean. The bio-optical and mixed layer model for optically pure sea water was forced with climatological environmental conditions to provide a reference simulation for 140°W in the eastern Equatorial Pacific Ocean. This reference simulation was used for comparison to other simulations which considered the effects of variations in wind stress and solar input for a homogeneous chlorophyll a profile and variations in the magnitude …