Physical Sciences and Mathematics Commons^™

An Assessment Of Alternative Feed Ingredients In Practical Diets For Florida Pompano (Trachinotus Carolinus) Held In Low Salinity Recirculating Systems, Terhea Nichole Williams

Electronic Theses and Dissertations

The identification of alternative protein sources for partial or whole replacement of fishmeal (FM) is a priority in the development of suitable, low cost feed formulations for the Florida pompano (Trachinotus carolinus). To evaluate alternative feed ingredients for the potential replacement of FM in diets fed to juvenile pompano, a series of four experiments were conducted. The objectives of Experiments 1 and 2 were to determine the apparent digestibility of crude protein (ADCP), energy (ADE), and apparent amino acid availability (AAAA) of three plant based ingredients (soybean meal (SBM), soy protein isolate (SPI), corn gluten meal (CGM)) and three by-product …

Spatial Analyses And Repletion Of Gargathy Coastal Lagoon, Loreto Herraiz Gomez

OES Theses and Dissertations

Coastal lagoons and bays vary in shape and size in response to antecedent topography, geologic processes and sea level rise. Variations in shape and environmental conditions of coastal basins are believed to influence the distribution of benthic sub-environments and the exchange of water with the ocean and other adjacent coastal systems. Gargathy Inlet and its coastal lagoon vary spatially from the inlet, where the greatest depths are observed, to the mainland, dominated by shallow intertidal areas, colonized by marsh. Hypsographic and hydro-hypsographic analyses of Gargathy's coastal lagoon were the primary techniques applied to understand the relative distribution of the benthic …

Modeling The Seasonal Sea Ice Cycle In The Ross Sea, Antarctica, Yusuf Sinan Hûsrevoğlu

OES Theses and Dissertations

A mesoscale resolution (5 km) regional ocean model (ROMS), coupled thermodynamically/dynamically to a sea ice model (CICE) and thermodynamically to an ice shelf is used to investigate Ross Sea seasonal sea ice cycle, polynya dynamics, distribution and transformations of continental shelf water masses, and bottom water formation. Daily atmospheric forcing is from the ECMWF ERA-40 dataset, and for a separate simulation, wind forcing for Terra Nova Bay is substituted from daily automatic weather station (AWS) data. Simulated Ross Sea sea ice concentration reproduces the winter lead opening events observed in the SSM/I signal; however, it underestimates open water area (rmsd …

Frontal Variability In Drake Passage - A Modeling Study, Bin Zhang

OES Theses and Dissertations

The Antarctic Circumpolar Current (ACC) features three major fronts: the Sub-antarctic Front (SAF), the Polar Front (PF), the Southern ACC Front (SACCF). The locations of these fronts are not stable. The PF can shift away from its historical mean locations on the order of 100 km. The ACC transport in Drake Passage varies over a large range (50 to 60 Sv). Numerical simulations with the Regional Ocean Modeling System are carried out to study the frontal variability under the influence of ACC transport, local wind stress and bottom topography in Drake Passage.

Front-embedded numerical experiments are carried out without surface …

The Survival Benefit Of Benthic Macroalgae Gracilaria Vermiculophylla As An Alternative Nursery Habitat For Juvenile Blue Crabs, Justin A. Falls

Dissertations, Theses, and Masters Projects

The Chesapeake Bay blue crab is in decline. One of the threats to it is the loss of its once plentiful nursery habitat, seagrass, due to baywide eutrophication and climate change. The emergence of the non-native benthic macroalga Gracilaria vermiculophylla may offer the blue crab an alternative nursery if it can provide juvenile crabs a refuge from predation. The ability of Gracilaria to protect juvenile blue crabs was investigated in mesocosm and field survival studies, which were combined into a larger dataset. All of these studies used tethering and therefore a tethering validation study in mesocosms accompanied these experiments. In …

Interspecific Interactions In Oyster Reef Communities: The Effect Of Established Fauna On Oyster Larval Recruitment, Brian B. Barnes

Dissertations, Theses, and Masters Projects

The behaviors of oyster larvae are difficult to monitor or experimentally manipulate, especially in field conditions. As a result, little is known of the fate of oysters in the larval portion of their life cycle, prior to recruitment. At the transition from pelagic larvae to benthic adults, larvae are likely to come into contact with many invertebrates resident on oyster reefs. Of these, fouling epifauna are generally believed to reduce the settlement of interspecific larvae through competitive exclusion and predation. Studies of these interactions, however, often utilize artificial settlement panels, which can exhibit different recruitment patterns to those observed on …

Idiopathic Lesions And Visual Deficits In The American Lobster (Homarus Americanus) From Longs Island Sound, Ny, Christopher Robert Magel

Dissertations, Theses, and Masters Projects

In 1999 a mass mortality of the American lobster (Homarus americanus) occurred in western Long Island Sound (WLIS). Although the etiology remains unknown, warm bottom water temperature, hypoxia, heavy metal poisoning, and pesticides have been suggested as casual factors. Subsequently, lobsters from WLIS have continued to display symptoms of morbidity that include lethargy and cloudy grey eyes, caused by idiopathic lesions. The effects of these lesions on lobster vision are unknown. We therefore used electoretinography (ERG) to document changes in visual function in lobsters obtained from WLIS, while simultaneously using histology to quantify the extent of damage. Of the lobsters …

A Molecular Analysis Of Atlantic Menhaden (Brevoortia Tyrannus) Stock Structure, Abigail J. Lynch

Dissertations, Theses, and Masters Projects

Atlantic menhaden is an ecologically and economically important species along the U.S. east coast. As a filter-feeder and key prey fish, it provides a critical link between primary production, phytoplankton, and larger piscivorous predators, such as striped bass, bluefish, and weakfish. The species is also the target of one of the largest commercial fisheries in the country. Menhaden are assessed as a single, coastwide stock, and recent assessments indicate that it is not overfished. However, there is very limited population genetics data to support the assumption of a single stock. Additionally, the recent consolidation of the fishery and localization of …

Effects Of Shoreline Development And Oyster Reefs On Benthic Communities In Lynnhaven, Virginia, Amanda Sue Lawless

Dissertations, Theses, and Masters Projects

Shoreline hardening and construction of restoration oyster reefs are occurring at rapid rates throughout Chesapeake Bay and little research has been conducted to determine whether installment of a hardened shoreline and oyster reef placement has an effect on the surrounding benthic infaunal communities. I investigated the effects of shoreline development and oyster reefs on benthic communities in Lynnhaven, Virginia. Throughout Lynnhaven, I determined the effects of shoreline type (natural marsh, oyster reef, rip-rap and bulkhead), sediment grain size, Total Organic Carbon/Total Nitrogen (TOC/TN) of the sediment, and predation (caging study) on density, biomass, and diversity of benthic infauna. An information-theoretic …

Zooplankton Community Structure In A Cyclonic And Mode-Water Eddy In The Sargasso Sea, Bethany Rose Eden

Dissertations, Theses, and Masters Projects

Recent evidence suggests that mesoscale eddies are an important mechanism for supplying nutrients to the surface waters of oligotrophic gyres. However, little is known about the biological response to these physical perturbations. Because mesozooplankton play a key role in food-web interactions and the flux of carbon and other elements from surface waters, changes in mesozooplankton community structure can affect biogeochemical cycling. During the summers of 2004 and 2005, respectively, we followed the development of a cyclonic eddy and an anti-cyclonic mode-water eddy in the Sargasso Sea. Zooplankton tows were conducted across both eddies using a Multiple Opening and Closing Net …

Twine-Top Modifications Of Sea-Scallop Dredges: Reducing Yellowtail-Flounder Bycatch, Kelli A. Milleville

Dissertations, Theses, and Masters Projects

No abstract provided.

Novel Use Of A Natural Isotope Signature To Track Recruitment And Evaluate Age Determination Methods For The 2002 Year Class Of American Shad In The York River, Sally A. Upton

Dissertations, Theses, and Masters Projects

No abstract provided.

Recent Sedimentation Patterns And Facies Distribution On The Waipaoa River Shelf, N.Z, Lila Eve Rose

Dissertations, Theses, and Masters Projects

No abstract provided.

A Modern Sediment Budget For The Continental Shelf Off The Waipaoa River, New Zealand, Andrea J. Miller

Dissertations, Theses, and Masters Projects

No abstract provided.

Mesopelagic Zooplankton Feeding Ecology And Effects On Particle Repackaging And Carbon Transport In The Subtropical And Subarctic North Pacific Ocean, Stephanie E. Wilson

Dissertations, Theses, and Masters Projects

Differences in zooplankton community structure and diet within the mesopelagic zone (base of euphotic zone to 1000 m) play a key role in affecting the efficiency by which organic matter is exported to depth, but how the structure of mesopelagic food webs change with depth or location is poorly known. I examined how mesopelagic zooplankton affect particle export in an oligotrophic (Hawaii Ocean Time-series site ALOHA) compared to a mesotrophic (Japanese time series site K2) open-ocean system. In the first part of the study, I investigated how fecal pellet characteristics change with depth in order to quantify the extent of …

Acoustic Measurements Of Cohesive Sediment Transport: Suspension To Consolidation, Ho Kyung Ha

Dissertations, Theses, and Masters Projects

This dissertation aims at utilizing the acoustic approach to measure cohesive sediment behaviors including (1) suspension, (2) settling, (3) deposition and (4) consolidation. The first two processes were attempted to interpret by means of backscattered signal analysis, while the last two processes were done by echo signal analysis. The acoustic instruments used in this study include Acoustic Doppler Velocimeter (ADV), Pulse Coherent Acoustic Doppler Profiler (PC-ADP) and Micro-Chirp system. Used sediments are pure kaolinite and in-situ sediments collected from Mai Po and Clay Bank. 5-MHz ADV was used to estimate the suspended sediment concentration (SSC) and settling velocity (ws). For …

Nearshore Morphology And Lithology: Links To Framework Geology And Shoreline Change, Jennifer L. Miselis

Dissertations, Theses, and Masters Projects

Despite evidence of the geologic and morphologic complexity of inner shelves worldwide, there is a paucity of observations from the nearshore, inhibiting direct comparison of these factors to coastal change. Using geophysical instruments to characterize the geology of the nearshore, this research focuses on the relationships between nearshore stratigraphy, sediment heterogeneity, shoreface morphology and shoreline behavior. While generally not considered in engineering models of shoreline evolution, these factors influence nearshore processes. Overall, the findings presented highlight the importance of nearshore geology, both at the seafloor and underlying it, in contributing to modem sediment transport processes affecting beaches. Shallow, sub-seafloor geology …

Age, Growth, And Demography Of The Sandbar Shark, Carcharhinus Plumbeus, Over Temporal And Spatial Scales, Jason G. Romine

Dissertations, Theses, and Masters Projects

Numbers of sandbar sharks, Carcharhinus plumbeus, in the Northwest Atlantic have experienced drastic declines since the early 1980's reaching their minima during the early 1990's. Catch rates in the early 1990's were a mere 25% of those during the 1980's. Such drastic reductions in other fish stocks have often caused compensatory responses, most notably the cod stocks in the Northwest Atlantic. Compensatory responses in depressed populations may include decreased natural mortality, increased fecundity, or increased growth rates. Compensation for population fluctuations below carrying capacities have been recognized for many terrestrial and oceanic r-selected organisms, but few instances have been noted …

Nutrient And Carbon Dynamics In The Chesapeake Bay Outflow Plume And Their Effect On The Coastal Ocean Environment, Katherine C. Filippino

OES Theses and Dissertations

Seasonally resolved nutrient and carbon fluxes from estuaries to the coastal ocean are poorly constrained. Nutrient and carbon cycling in highly productive regions like the Chesapeake Bay outflow plume and surrounding coastal environments greatly affect our global understanding of carbon cycling. The overall questions for the research described in this dissertation stem from the need to close global carbon budgets, and obtain a fundamental understanding of nutrient dynamics in a coastal region heavily influenced by seasonality and human impacts.

Within the framework of physical characteristics of the outflow plume and through the characterization of nutrient concentrations, primary productivity rates, and …

Natural Mortality Of Blue Crab: Estimation And Influence On Population Dynamics, David A. Hewitt

Dissertations, Theses, and Masters Projects

The blue crab Callinectes sapidus supports one of the most important fisheries in the Chesapeake Bay and is the leading contributor to blue crab landings in the United States. Assessment and management of blue crab stocks has been hampered by a lack of estimates of natural mortality rates, a key parameter in assessment models. In Chapter 2, we demonstrate that the approach used for estimating natural mortality that had been used in past assessments was flawed, and provide justification for a superior alternative. In Chapter 3, we synthesize our current understanding of natural mortality rates in adult blue crab and …

Bottom-Up And Top-Down Controls On Sedimentary Ecosystem Functioning In A Seagrass Habitat, Amanda C. Spivak

Dissertations, Theses, and Masters Projects

Coastal seagrass ecosystems are complex habitats that are increasingly influenced by human perturbations. Disturbances that affect the strength of bottom-up (i.e. resource availability) and top-down (i.e. consumer) controls may also influence biomass distribution between trophic levels, sediment biogeochemistry, and seagrass ecosystem metabolism. Here, I experimentally tested how top-down and bottom-up perturbations interact with community structure (diversity, food chain length of epibenthic consumers) to alter sediment biogeochemistry and ecosystem metabolism in an experimental eelgrass (Zostera marina ) system. My data indicated that resource availability influenced SOM composition and ecosystem metabolism. Light availability tended to be a stronger determinant of SOM composition …

A Bio-Economic Feasibility Model For Remote Setting: Potential For Oyster Aquaculture In Virginia, Michael Spohn Congrove

Dissertations, Theses, and Masters Projects

No abstract provided.

Factors Controlling Tidal Flat Morphology In South San Francisco Bay Between The 1890s And 2005, Joshua Alexander Bearman

Dissertations, Theses, and Masters Projects

There is currently a project underway to restore many of the man-made salt ponds along the shores of South San Francisco Bay (SSFB) back to tidal marsh, potentially reestablishing these areas as sinks for SSFB sediments. While there have been recent studies examining the evolution of newly restored marsh areas in SSFB, there have been no recent projects focusing on the expected response of valuable tidal flat environments adjacent to the restored marshes. To help fill this void, this project seeks to characterize SSFB tidal flat morphodynamics, both spatially and temporally, through examination of historic morphologic variability and change along …