Terrestrial and Aquatic Ecology Commons^™

A Comprehensive Evaluation Of C25 Highly Branched Isoprenoid Alkenes Of Marine Diatoms As Proxies For Sea Ice Extent In The Arctic Ocean, Tetiana Muniak

OES Theses and Dissertations

Sea Ice extent is one of the major factors regulating carbon cycling and ecosystem function in the modern Arctic Ocean. It is an essential component of climate models and is crucial for the evaluation of various oceanographic processes that influence a particular region. Yet it is also one of the most difficult attributes of the ocean with respect to our ability for its accurate reconstruction from paleo records. The lack of the detailed records prior to satellite information has encouraged the development of new proxy records for the reconstruction of past

sea ice conditions. In recent years, a new monounsaturated …

Spatial And Temporal Variability In Net Community Metabolism In The Middle Atlantic Bight, Georges Bank, And Gulf Of Maine: Observations Of Net Heterotrophic Phases In The Highly Productive Coastal Zone, Cory James Staryk

OES Theses and Dissertations

Net community metabolism (NCM), the balance between primary production and community respiration, was measured during two cruises, June 2011 and August 2012, in the Middle Atlantic Bight, Georges Bank and Gulf of Maine. Net heterotrophy was observed in Georges Bank and Gulf of Maine during the June 2011 cruise. During the August 2012 cruise, net heterotrophy was observed in the Middle Atlantic Bight and net autotrophy was observed in Georges Bank and the Gulf of Maine. Dark community respiration increased (DCR) with biomass and temperature. Gross community production (GCP) also increased with Chl a, bicarbonate uptake, and temperature. Net …

Population Structure And Connectivity Of An Important Pelagic Forage Fish In The Antarctic Ecosystem, Pleuragramma Antarcticum In Relation To Large Scale Circulation, Jason W. Ferguson

OES Theses and Dissertations

Ocean circulation has been identified as a major process controlling the distribution of biological material in marine systems. Large-scale transport by the Antarctic Circumpolar Current (ACC), the Ross and Weddell Gyres, and the Antarctic Coastal Current can promote spatially complex population structure in the Southern Ocean through advection. Antarctic silverfish (Pleuragramma antarcticum), a pelagic, neutrally buoyant notothenioid fish species, are distributed around the shelf systems of Antarctica and are considered an important species rivaling krill as prey for many birds, seals, whales, and other fish. We asked whether silverfish are distributed in independent, discrete populations along the shelf systems of …

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 …

Interannual Variation Of Stratification In Lower Chesapeake Bay, Christopher S. Katzenmiller

OES Theses and Dissertations

Stratification in the water column can prove to be an important indicator to the state of the water column and ecosystem. The focus of this research is to evaluate trends in stratification in the Lower Chesapeake Bay. Detailed analysis was performed on a 14 year data set to study interannual variation in the region of study. Potential energy anomaly was used to quantify stratification. Potential energy anomaly is the amount of energy required to mix a water column. It is determined from the vertical density structure of density. Potential energy anomaly is the departure of potential energy from climate conditions. …

Picoplankton/Phytoplankton Dynamics In Hampton Roads, Virginia, Leslie E. Dorworth

OES Theses and Dissertations

The biomass distribution of the three main size components of the phytoplankton (net, nano, and picoplankton) was examined in the lower Chesapeake Bay. Work was done at two stations during the spring and neap tidal cycles when freshwater flow into the bay was at its seasonal minimum and maximum. Emphasis was placed on how the picoplankton ( < 2.0 μm, > 0.2 μm) reacted during the sampling period.

Picoplankton made up approximately 13% of the total biomass, during the observed time period, at the more oceanic station. The picoplankton fraction contributed up to 16% of the total biomass at the estuarine station. From this …

The Spatial And Temporal Distribution Of Fish Eggs And Larvae In Hempstead Bay Estuary, Joseph Adelard Lessard

OES Theses and Dissertations

The ichthyoplankton of Hempstead Bay estuary was sampled from December 1972 to mid March 1974. Eleven stations were sampled by towing a 0.5 meter diameter plankton net. Eggs were most abundant during June and July with an average concentration calculated to be above 5,500/100m³. Egg densities were the lowest during the fall and winter. Larvae were most frequently taken from March through July with densities varying greatly among the samples. The eggs of Brevoortia tyrannus, Anchoa mitchilli, Tautoga onitis, Tautogolabrus adspersus, and Scophthalmus aguosus and the larvae of Menidia menidia, Ammodvtes hexapterus and Pseudopleuronectes americanus constituted most …

Feeding Ecology Of Black Sea Bass Centropristis Striata On An Artificial Reef Off Virginia (Perciforms: Serranidae), Ping K. Chee

OES Theses and Dissertations

The feeding ecology of the black sea bass, Centropristis striata, associated with artificial reefs shows seasonal and size-related changes. Monthly collections totaling 520 black sea bass taken from an artificial reef near the Chesapeake Light Tower, Virginia, between August 1975 and May 1976, were analyzed for food habits as revealed by number, volume, frequency of occurrence and a modified Index of Relative Importance.

The black sea bass feeds on the artificial reef as well as the adjacent areas. When food was abundant on the reef, food items from the reef and the surrounding area were consumed. Upon depletion of the …

Effect Of The Chesapeake-Elizabeth Sewage Outfall Virginia Beach, Virginia On The Distribution And Ecology Of Benthic Foraminifera, James M. Bates Jr.

OES Theses and Dissertations

Sediment and bottom water samples from seven stations at the Chesapeake Elizabeth sewage outfall, Virginia Beach, Virginia were collected in order to evaluate the effect of the outfall on benthic foraminifera. The top centimeter of sediment was analyzed for living and total (live plus dead) foraminiferal densities, chlorophyll a, sediment grain size, ATP, percentage of silt and clay, and total organic carbon. Bottom water salinity, temperature, and ammonia were also analyzed.

Living foraminiferal density increased from March to July and with distance from the outfall. Total foraminiferal density also increased from March to July. The set of environmental variables was …

Microbenthic Algal Production Of An Intertidal Sandflat In Little Creek Harbor, Virginia Beach, Virginia, Clayton Barry Shedrow

OES Theses and Dissertations

Estimated annual net microbenthic algal production of an intertidal sandflat on Little Creek Inlet, Virginia Beach, Virginia, was 105 g C/m². Seasonally, primary production was greatest during the summer and fall periods (38 and 49 g C/m², respectively). Productivity was found to vary directly with water temperature and standing crop of benthic diatoms, and inversely with incident solar radiation and standing crops of sedimentary chlorophyll 'a' and 'c'. Orthophosphate and nitrate-N appeared to be limiting factors, nitrate-N more so than orthophosphate. Mean annual net photosynthetic efficiency (based upon total light) for the microphytobenthic community was 0.09%. …