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Articles 1 - 9 of 9
Full-Text Articles in Physical Sciences and Mathematics
Fecal Pellet Production By North Atlantic Zooplankton, Michael Gibson
Fecal Pellet Production By North Atlantic Zooplankton, Michael Gibson
Undergraduate Honors Theses
Fecal pellet carbon (FPC) production by zooplankton is a significant component of the ocean’s biological carbon pump: the suite of biological processes that mediate export of carbon to the deep ocean, ultimately leading to the sequestration of atmospheric carbon dioxide in the ocean. In this study, mesozooplankton (zooplankton 0.2 mm to ~2 cm) were collected from the epipelagic zone in the temperate North Atlantic Ocean during day and night in May 2021. Zooplankton were live separated into five size fractions and incubated on board ship in natural surface seawater to measure fecal pellet production rate of the mixed mesozooplankton community. …
Identifying Factors Controlling Dinophysis Spp. Feeding, Growth, And Toxin Production Through Field And Lab Studies, Vanessa R. Strohm
Identifying Factors Controlling Dinophysis Spp. Feeding, Growth, And Toxin Production Through Field And Lab Studies, Vanessa R. Strohm
Dissertations, Theses, and Masters Projects
Harmful algal blooms (HABs) and their associated phycotoxins pose a threat to both human and shellfish health around the world. Dinophysis spp., a causative organism of diarrhetic shellfish poisoning (DSP) in humans, and its two toxin classes: dinophysistoxins (DTXs) and pectenotoxins (PTXs), have been documented throughout the year in the Chesapeake Bay. While DTX concentrations currently remain below regulatory limits in regional seafood products, further research is needed to understand environmental drivers, both biotic and abiotic, that may be impacting Dinophysis spp. feeding on prey, growth, and toxin production. To characterize populations of Dinophysis in situ, an Imaging FlowCytobot (IFCB) …
Emerging Red Sore Disease Of American Eel (Anguilla Rostrata) In Chesapeake Bay: Etiology, Epidemiology, And Impacts In Aquaculture And The Wild, Amanpreet Kaur Kohli
Emerging Red Sore Disease Of American Eel (Anguilla Rostrata) In Chesapeake Bay: Etiology, Epidemiology, And Impacts In Aquaculture And The Wild, Amanpreet Kaur Kohli
Dissertations, Theses, and Masters Projects
Emerging infectious diseases in aquatic systems, both in aquaculture and in the wild, are a global concern. Many have proposed an uptick in marine diseases as a result of environmental changes including a warming climate, habitat modifications, trade and transfer of wildlife and aquaculture products, pollution, overharvesting of resources, and other anthropogenic impacts. These perturbations can disturb the delicate host-pathogen relationships and result in new diseases or exacerbate the existing diseases in a population. Diseases can lead to several direct and indirect effects in the ecosystem such as population declines and extinctions, and thereby a change in population dynamics, as …
Chesapeake Bay Carbonate Cycle: Past, Present, And Future, Fei Da
Chesapeake Bay Carbonate Cycle: Past, Present, And Future, Fei Da
Dissertations, Theses, and Masters Projects
Multiple natural and anthropogenic drivers are expanding the variability of the estuarine carbonate system (CO2 system). These changes in the CO2 system are threatening the health of ecologically and economically important bivalve species. This dissertation investigates the Chesapeake Bay CO2 system by using numerical models and historical water quality data, focusing on the past three decades, the contemporary period, and the late 2060s. In Chapter 2, sensitivity experiments are conducted with a 3-D Chesapeake Bay hydrodynamic-biogeochemical model and reveal that the magnitude of decadal trends in the CO2 system over the past 30 years is much greater than that observed …
Impacts And Uncertainties Of Climate Change On The Chesapeake Bay, Kyle E. Hinson
Impacts And Uncertainties Of Climate Change On The Chesapeake Bay, Kyle E. Hinson
Dissertations, Theses, and Masters Projects
Climate change impacts in the Chesapeake Bay will limit the efficacy of nutrient reduction efforts and decrease dissolved oxygen, but uncertainties associated with the magnitude of these effects remain. An understanding of underlying mechanisms that have driven recent warming trends will narrow uncertainties for future pathways of temperature change. Additionally, future simulations of climate impacts in the estuary are dependent on multiple different sources of uncertainty, many of which have not yet been fully evaluated. This dissertation used a three- dimensional coupled hydrodynamic-biogeochemical model to investigate recent warming trends as well as underlying uncertainties likely to influence regional projections of …
Climate Impacts On Spatiotemporal Habitat Usage Of Mid-Atlantic Fishes, Adena Jade Schonfeld
Climate Impacts On Spatiotemporal Habitat Usage Of Mid-Atlantic Fishes, Adena Jade Schonfeld
Dissertations, Theses, and Masters Projects
Climate change has altered marine environments, most notably by increasing water temperatures and reducing dissolved oxygen concentrations. These persistent changes have impacted the phenology and spatiotemporal habitat usage of mobile species, often through distributional shifts poleward or to deeper water. Climate-driven distributional shifts have been documented for numerous species inhabiting the Atlantic Ocean along the US East Coast, a region disproportionately affected by climate change. Adjacent estuaries are experiencing similar alterations to their physical environments and biotic community composition. Many estuarine species are seasonal residents and changes to environmental conditions within an estuary can result in altered usage and residence …
Development Of 3d And 360 Gis-Based Models To Visualize Projected Sea Level Rise In Coastal Virginia, Candice M. Vinson
Development Of 3d And 360 Gis-Based Models To Visualize Projected Sea Level Rise In Coastal Virginia, Candice M. Vinson
Dissertations, Theses, and Masters Projects
Science communication is a skill that can be strengthened with practice. Like any skill, it helps to know what you need to practice in order to get better at it. When presenting information to an audience, the skill of science communication comes into play as early as the first draft of a presentation. As you think about how you will tell your story to the audience, you likely consider including text on slides, images, graphs, maps, or even videos. However, it is crucial to remember that accessibility barriers are something we must often consciously work to rid our presentations of, …
Succession Of The Late Summer Phytoplankton Blooms In The York River Estuary, Va, Heather Kathleen Corson
Succession Of The Late Summer Phytoplankton Blooms In The York River Estuary, Va, Heather Kathleen Corson
Dissertations, Theses, and Masters Projects
The influence of bottom-up and top-down controls on the formation and persistence of phytoplankton blooms has been well studied. However, the relative importance of these bottom-up and top-down controls vary spatially and temporally. In the tidal tributaries and mainstem of Chesapeake Bay, the summer dinoflagellate population follows a succession of bloom-producing species. The dinoflagellate species Margalefidinium polykrikoides and Alexandrium monilatum are currently considered the end of this succession. These species form near-annual blooms in the lower half of Chesapeake Bay and are considered harmful algal bloom (HAB) species due to their negative ecological impacts. However, analysis of long-term monitoring data …
Biotic And Abiotic Factors Associated With Temporal And Spatial Variability Of Constitutive Mixotroph Abundance And Proportion, Marcella Dobbertin Da Costa
Biotic And Abiotic Factors Associated With Temporal And Spatial Variability Of Constitutive Mixotroph Abundance And Proportion, Marcella Dobbertin Da Costa
Dissertations, Theses, and Masters Projects
Mixotrophic protists, which combine the use of photosynthesis and prey ingestion to obtain nutrients for growth, comprise a substantial portion of the plankton community. However, there is a major gap in our understanding of how mixotroph prevalence varies spatially and temporally and under what conditions they dominate. I utilized a recently developed molecular technique to experimentally identify active mixotrophs (taxa identified to be grazing when samples were collected) and combined this with microscopy data to estimate active mixotroph abundance and proportion at two locations in a temperate estuary over a year. Active mixotroph abundance was compared to potential mixotroph (taxa …