Physical Sciences and Mathematics Commons^™

Interannual And Regional Differences In Krill And Fish Prey Quality Along The Western Antarctic Peninsula, Kate E. Ruck

Dissertations, Theses, and Masters Projects

Polar zooplankton and fish safeguard against the seasonality of food availability by using the summer months to build large reserves of lipids, which in turn are utilized to meet the metabolic demands of apex predators such as penguins, seals, and whales. A warming trend in the northern part of the western Antarctic Peninsula (WAP) has led to a decrease in perennial and summer sea ice, an increase in heat content over the shelf, and lower phytoplankton biomass, which could affect prey quality. We compared prey quality, including elemental (C, N) content and ratios, total, neutral, and polar lipid content, and …

Movements, Growth, And Mortality Of Chesapeake Bay Summer Flounder Based On Multiple Tagging Technologies, Mark J. Henderson

Dissertations, Theses, and Masters Projects

The research projects presented in this dissertation used multiple tagging technologies to examine the movements, growth, and mortality rates of summer flounder tagged and released in Chesapeake Bay. In the first two chapters, I used acoustic, archival, and conventional tags to examine the behavior of summer flounder on different spatial scales. Investigating the movement behavior of individuals on different scales is an important step towards understanding how large-scale distributions of a population are established. Based on the observed behaviors of summer flounder, I hypothesize that the movements of these fish are primarily related to foraging behavior while they are resident …

Seed Burial In The Seagrass Zostera Marina: The Role Of Infauna, Natalia J. Blackburn

Dissertations, Theses, and Masters Projects

In terrestrial systems, seed burial is widely recognized as a vital process that influences small- and large-scale plant population patterns. Despite its demonstrated importance in terrestrial literature, very little is known about seed burial in seagrasses. Zostera marina is a perennial seagrass found in northern temperate oceans worldwide, and is the dominant seagrass found in the Chesapeake Bay. In terrestrial systems, seed burial is frequently mediated by soil-dwelling invertebrates. The goal of this work was to determine the role that benthic infauna play in the burial of Z. marina seeds by addressing the following questions: 1. Are seeds on sediments …

Patterns Of Population Structure And Historical Dispersal In Squaloid Sharks: A Species-Level Approach Using Molecular Markers, Ana Christina Pimenta Verissimo

Dissertations, Theses, and Masters Projects

Squaloids (Order Squaliformes) are a highle diverse group of mostly deepwater habitats (> 200 m). Many species are regularly caught in commercial fisheries worldwide but their low productivity and correspondingly low intrinsic rebound potentials make them particularly vulnerable to population depletion and overexploitation. of special concern to fisheries management and conservation efforts are the spiny dogfish Squalus acanthias, the leafscale gulper shark Centrophorus squamosus and the Portuguese dogfish Centroscymnus coelolepis. These taxa have recently been declared overfished in several parts of each species' distribution but management efforts have been made to recover the "stocks" without a good understanding of the …

Rogue Fishermen: Codfish, Atlantic Items, And The Isles Of Shoals, Megan Victor

Dissertations, Theses, and Masters Projects

No abstract provided.

The Role Of Benthic Nitrogen Fixation As A Source Of New Nitrogen To The New River Estuary, Nc, Meaghan L. Whitehead

Dissertations, Theses, and Masters Projects

Nitrogen (N) has been shown to limit primary production in many estuarine systems, including the New River Estuary (NRE), NC, a moderately eutrophied system with large areas of photic sediment. The NRE receives major inputs of allochthonous nutrients from agriculture and confined animal feeding operations as well as other sources. Autochthonous sources of N in the NRE include both remineralization and Nfixation. Whereas allochthonous sources are usually most important in winter/spring and during periods of high fresh water discharge, autochthonous sources are likely to become more important in summer. N-fixation, which can be performed by both autotrophic cyanobacteria and heterotrophic …

Distribution And Feeding Ecology Of Bathylagus Euryops (Teleostei: Microstomatidae) Along The Northern Mid-Atlantic Ridge From Iceland To The Azores, Christopher J. Sweetman

Dissertations, Theses, and Masters Projects

The northern Mid-Atlantic Ridge, from Iceland to the Azores (MAR), ranges in depth from 800 – 4500 m and extends over an area of 3.7 million km2. Recent evidence from MAR-ECO, a Census of Marine Life field project, reported increased abundance and biomass of deep-pelagic fishes below 1000 m on the MAR. Among the fishes sampled, Bathylagus euryops was found to be the biomass-dominant species and ranked third in total abundance. In this thesis, we characterize the distribution and feeding ecology of B. euryops as a function of physical, biological, and life history parameters along a mid-ocean ridge system. Multiple …

Transport And Fate Of Sediment On The Waipaoa River Continental Shelf: Implications For The Formation And Reworking Of Flood Deposits, Julia M. Moriarty

Dissertations, Theses, and Masters Projects

As part of a large interdisciplinary study, particulate fluxes in the Waipaoa River sedimentary system in New Zealand have been studied from the terrestrial headlands of the catchment to the oceanic basin over timescales spanning storm events, seasons, and the Holocene. Here, we complement prior efforts by evaluating the formation and reworking of riverine deposits during episodic flood and wave events, and considering their role in accumulation patterns created over longer timescales on the Waipaoa shelf. Using a numerical hydrodynamic and sediment transport model, sediment fluxes and deposition were analyzed from January 2010 through February 2011.

A version of the …

Shedding Light On The Estuarine Coastal Filter: The Relative Importance Of Benthic Macroalgae In Shallow Photic Systems, Johnathan Daniel Maxey

Dissertations, Theses, and Masters Projects

No abstract provided.

Microzooplankton Community Structure And Grazing Impact Along The Western Antarctic Peninsula, Lori M. Price

Dissertations, Theses, and Masters Projects

Microzooplankton (zooplankton 20 – 200 μm) are an integral part of aquatic food webs as they can be significant grazers of phytoplankton and bacteria, remineralizers of nutrients, and prey for higher trophic levels. The importance of microzooplankton in many pelagic ecosystems has been established, yet compared to larger zooplankton, microzooplankton are understudied in the Southern Ocean. I quantified microzooplankton community composition and grazing rates along the Western Antarctic Peninsula (WAP) as part of the Palmer Antarctica Long-Term Ecological Research project (PAL LTER). This region is experiencing rapid warming, causing declines in sea ice and changes in the marine food web. …

The Effects Of Salinity Pulses Of Varying Duration And Intensity On Three Freshwater Submerged Aquatic Vegetation Species, Rebecca Wright

Dissertations, Theses, and Masters Projects

No abstract provided.

Habitat Utilization And Trophic Interactions By Fauna In A Shallow Estuary: Comparisons Between Clam Aquaculture And Natural Sites, Lara Gates Kling

Dissertations, Theses, and Masters Projects

Aquaculture of the hard clam, Mercenaria mercenaria, has steadily increased in the United States over the past 25 years. In some areas, including along Virginia’s coast, this industry has grown to such a scale that aquaculture systems now exist as agroecosystems within coastal waters. Several features of these aquaculture systems, such as high clam densities and protective mesh netting, may modify the availability of habitat, food, and nutrients and may be expected to affect benthic and nektonic community structure. Few studies, however, have evaluated these effects. We conducted seasonal (May – September) sampling in a tidal tributary of Chesapeake Bay …

Myctophid Feeding Ecology And Carbon Transport Along The Northern Mid-Atlantic Ridge, Jeanna M. Hudson

Dissertations, Theses, and Masters Projects

The Mid-Atlantic Ridge (MAR) is the largest topographic feature in the Atlantic Ocean, yet little is known about the food web structure and trophic ecology of fishes inhabiting mesopelagic waters along the MAR. To better understand the food web structure and to compare the feeding ecology of abundant MAR fishes to those in offridge areas, MAR-ECO, a Mid-Atlantic Ridge ecosystem field project of the Census of Marine Life, sampled the pelagic fauna of the northern MAR (Iceland to the Azores) during June-July, 2004. Samples were collected with two midwater trawls outfitted with multiple opening and closing cod ends to sample …

Evaluating The Impact Of Stock Structure Uncertainty In Stock Assessments Of Sailfish In The Atlantic Ocean, Catarina Wor Lima

Dissertations, Theses, and Masters Projects

No abstract provided.

Mobile Animals As A Potential Dispersal Mechanism In Zostera Marina (Eelgrass), Sarah E. Sumoski

Dissertations, Theses, and Masters Projects

No abstract provided.

Effects Of Life History And Physical Variables On Winter Distribution Of Blue Crabs In Chesapeake Bay, Gabrielle G. Saluta

Dissertations, Theses, and Masters Projects

No abstract provided.

Relationships Among Fine Sediment Settling And Suspension, Bed Erodibility, And Particle Type In The York River Estuary, Virginia, Kelsey A. Fall

Dissertations, Theses, and Masters Projects

In order to understand the processes controlling the temporal variability in settling velocity (Ws) and bed erodibility (ε), in the middle reaches of the York River estuary, VA, the relationships between the hydrodynamics and particle types were investigated with a near-­‐bed Acoustic Doppler Velocimeter (ADV) and the York River 3-­‐D Hydrodynamic Cohesive Bed Model.

ADV observations of the flow characteristics that occurred over a strong temporal transition period indicated that Ws and ε were characterized by two distinct regimes with contrasting sediment and water column characteristics: (i) a physically-­‐dominated regime (Regime 1) which was a period dominated by flocculated muds …

Life History And Ecology Of The Freshwater Amphipods Gammarus Pseudolimnaeus And Gammarus Fasciatus In Southeastern Virginia, Lindsey L. Postaski

Dissertations, Theses, and Masters Projects

No abstract provided.

Developing An Unstructured Grid, Coupled Storm Surge, Wind Wave And Inundation Model For Super-Regional Applications, Yi-Cheng Teng

Dissertations, Theses, and Masters Projects

During extreme weather conditions such as hurricanes and nor'easters, both the currents and wind waves generated by the atmospheric forces are important. Although they may act and dominate on different temporal and spatial scales, their interactions and combined effects are without doubt significant. In this dissertation, a major effort has been made to couple an unstructured grid circulation model SELFE (semi-implicit, Eulerian-Lagrangian finite element model) and the WWM II (Wind Wave model II). Moreover, this new coupled model system can be executed in a parallel computational environment. After the coupled model was successfully built, the model was verified with ideal …