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Full-Text Articles in Physical Sciences and Mathematics
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 …
Evaluation Of Population Structure And The Interspecific Relationship Of Striped Marlin (Kajikia Audax) And White Marlin (K. Albida) Based On Traditional Or Genome-Wide Molecular Markers, Nadya Mamoozadeh
Dissertations, Theses, and Masters Projects
The istiophorid billfishes (marlins, spearfishes, and sailfish) are highly migratory pelagic fishes exhibiting broad and continuous spatial distributions in the Atlantic, Pacific, and Indian oceans. These species are targeted by a number of recreational, commercial, artisanal, and subsistence fisheries worldwide, and are also caught as bycatch in pelagic longline fisheries targeting tunas and swordfish. Though stock assessments have not been conducted for all istiophorids, assessments available for some species indicate that many istiophorid stocks are overfished and/or experiencing overfishing. However, the development of stock-specific recovery efforts is often impeded by a lack of information on basic species biology, including stock …
Patterns Of Abundance And Community Dynamics In Atlantic Coastal Sharks, Cassidy Peterson
Patterns Of Abundance And Community Dynamics In Atlantic Coastal Sharks, Cassidy Peterson
Dissertations, Theses, and Masters Projects
No abstract provided.
Oyster Reef Connectivity Inferred Via Population Genetic Analysis, Brendan Douglas Turley
Oyster Reef Connectivity Inferred Via Population Genetic Analysis, Brendan Douglas Turley
Dissertations, Theses, and Masters Projects
A panel of 48 single nucleotide polymorphism markers (SNPs) was developed for use in a population genetic analysis of the Eastern Oyster Crassostrea virginica sampled from the lower Chesapeake Bay. The SNPs were developed from published and unpublished sequencing data and developed to be used on a Fluidigm Biomark. A selection of 95 SNPs were chosen initially for development and the best 48 were selected for downstream applications. This project was a collaboration with the non-profit Chesapeake Bay Foundation (CBF) to examine their oyster reef restoration project in the Lafayette River, Virginia. The CBF wanted to test a hydrodynamic connectivity …
The Reproductive Biology Of Striped Bass (Morone Saxatilis) In Chesapeake Bay, Carissa L. Gervasi
The Reproductive Biology Of Striped Bass (Morone Saxatilis) In Chesapeake Bay, Carissa L. Gervasi
Dissertations, Theses, and Masters Projects
The Striped Bass (Morone saxatilis) is an anadromous finfish that supports a lucrative fishery along the Atlantic coast of the United States and serves as a vital component of estuarine food webs. Once Striped Bass stocks were restored after crashing in the late 1980s, abundance skyrocketed to record levels. Over the past decade however, abundance has steadily declined, concurrent with an outbreak of mycobacteriosis. Disease prevalence is currently >50%, and previous research has demonstrated diseasepositive fish exhibit slower growth and increased natural mortality compared to diseasenegative fish. The purpose of this research was to provide a contemporary description of Chesapeake …
Assessing The Impact Of Climate Change On Proposed Restoration Of The Lynnhaven River Ecosystem, Emily E. Skeehan
Assessing The Impact Of Climate Change On Proposed Restoration Of The Lynnhaven River Ecosystem, Emily E. Skeehan
Dissertations, Theses, and Masters Projects
Environmental degradation of the Chesapeake Bay (CB) and its sub-estuaries has been linked to population growth in the surrounding coastal zone, rapid development in the watershed and resultant nutrient loading into the Bay. Consequently, the federal government and its partners have developed restoration plans to mitigate the effects of eutrophication and improve essential ecosystem functions, though few restoration plans have considered the interactive effects of climate change. Climate change and other anthropogenic drivers are causing changes in ecosystem structure and function, thereby impacting the beneficial services ecosystems provide. While some studies have attempted to quantitatively predict the benefits of ecosystem …
A Model Of Carrying Capacity And Ecosystem Impacts In A Large-Scale, Bivalve-Dominated Agro-Ecosystem: Hard Clam Aquaculture In Cherrystone Inlet, Va, Michael A. Kuschner
A Model Of Carrying Capacity And Ecosystem Impacts In A Large-Scale, Bivalve-Dominated Agro-Ecosystem: Hard Clam Aquaculture In Cherrystone Inlet, Va, Michael A. Kuschner
Dissertations, Theses, and Masters Projects
With the recent growth of the hard clam aquaculture industry, sites of intensive aquaculture have emerged as large-scale agro-ecosystems where the success of aquaculture production is dynamically linked to ecosystem function. Large scale clam aquaculture operations are associated with a range of potential positive and negative feedbacks related to nutrient dynamics, water and sediment quality, proliferation of macroalgae, and carrying capacity. Quantitative modeling tools are needed to support system-level planning related to site selection, scale of operations, production capacity and ecosystem function. The purpose of this study was to develop a model for Cherrystone Inlet, VA, where one-third (1.9 km2) …
Bay Scallop, Argopecten Irradians, Restoration In The Virginia Coastal Bays: The Role Of Predation On Spring Vs Fall Cohort Survival, Erika L. Schmitt
Bay Scallop, Argopecten Irradians, Restoration In The Virginia Coastal Bays: The Role Of Predation On Spring Vs Fall Cohort Survival, Erika L. Schmitt
Dissertations, Theses, and Masters Projects
While the importance o f predation in controlling many natural bivalve populations is well established, it is often overlooked in the restoration strategies for depleted populations. Adult bay scallops {Argopecten irradians concentricus) along the U.S. mid-Atlantic coast spawn multiple times per year, typically once in the early summer and again in the early fall. Larvae generally settle on seagrass leaves to avoid benthic predators, but shift to the sediment surface around 20 mm in size when they become less vulnerable to predation. The objectives o f this study were to 1.) Determine proportional survival o f two distinct size classes …
Storm Event Impact On Organic Matter Flux, Composition And Reactivity In Taskinas Creek, Va, Sarah Schillawski Cammer
Storm Event Impact On Organic Matter Flux, Composition And Reactivity In Taskinas Creek, Va, Sarah Schillawski Cammer
Dissertations, Theses, and Masters Projects
Carbon export from the land to the ocean are an important part of the global carbon cycle, linking terrestrial watersheds and the global carbon cycle. Burial of terrestrial organic carbon represents a long term sink for atmospheric CO2. Approximately 0.4 Pg Cy-1 is delivered to the global ocean from rivers, equally divided between POC and DOC. However, the amount of carbon entering the ocean is a small portion of the total amount entering rivers from the terrestrial environment, suggesting a large amount of processing in inland waters and estuaries. Most monitoring efforts have focused the processing of organic matter on …
Quantification Of Nursery Habitats For Blue Crabs In Chesapeake Bay, Gina M. Ralph
Quantification Of Nursery Habitats For Blue Crabs In Chesapeake Bay, Gina M. Ralph
Dissertations, Theses, and Masters Projects
The blue crab is an iconic species in Chesapeake Bay, supporting important commercial and recreational fisheries and functioning as a critical link in the food web. Structurally complex habitats are often cited as nurseries for the blue crab, and other commercially important fish and crustacean species, by providing enhanced growth and survival for juveniles. I quantified the value of shallow habitats as nurseries for blue crabs through field studies and a demographic model. In Chapter 2, I utilized a two-year juvenile survey in vegetated habitats of the lower Bay to examine the effect of habitat complexity on the density of …
Studies Of Mortality Estimation, Amy Y. Then
Studies Of Mortality Estimation, Amy Y. Then
Dissertations, Theses, and Masters Projects
Instantaneous total mortality rate Z can be partitioned into two components: fishing, F, and natural mortality, M. A number of data-poor methods have been developed to estimate Z, F, and M, and these methods tend to rely on fairly restrictive assumptions as well as on data types that are easy to obtain, e.g., length or other life history information. The overarching goal of this dissertation is to contribute to the advancement of methods for estimating these important and influential stock parameters. The relevant issues and the gaps in knowledge pertaining to these data-poor methods are outlined in the Introduction chapter …
Effects Of Saltwater Intrusion On Vegetation Dynamics And Nutrient Pools In Low-Salinity Tidal Marshes, Pamunkey River (Virginia, Usa), Lori A. Sutter
Effects Of Saltwater Intrusion On Vegetation Dynamics And Nutrient Pools In Low-Salinity Tidal Marshes, Pamunkey River (Virginia, Usa), Lori A. Sutter
Dissertations, Theses, and Masters Projects
This study investigated vegetation changes in a former tidal freshwater marsh (TFM) to determine the role that salinity intrusion plays in vegetation dynamics. Field observations along a narrow salinity gradient in the Pamunkey River revealed that vegetation is shifting to fewer dominants with increasing salinity. Two remaining dominants, Peltandra virginica and Zizania aquatica (hereafter Peltandra and Zizania, respectively), had variable net CO2 assimilation throughout the growing season. Peltandra net CO2 assimilation declined both over the growing season and in marshes with higher salinity; whereas, Zizania generally increased over the growing season peaking in late summer. The same species' tissue nutrients …
Physiological Stress And Post-Release Mortality Of White Marlin (Kajikia Albida) Caught In The U.S Recreational Fishery, Lela Sylvia Schlenker
Physiological Stress And Post-Release Mortality Of White Marlin (Kajikia Albida) Caught In The U.S Recreational Fishery, Lela Sylvia Schlenker
Dissertations, Theses, and Masters Projects
White Marlin (Kajikia albida) is a highly migratory species that occurs throughout temperate and tropical regions of the Atlantic Ocean and is the basis of a large sport fishery along the United States Atlantic coast. The single, Atlantic-wide stock is considered to be overfished, with less than one-third the spawning biomass estimated to be necessary for maximum sustainable yield. Billfish management measures adopted by the International Commission for the Conservation of Atlantic Tunas (ICCAT) and implemented in the U.S. by the National Marine Fisheries Service (NMFS), as well as increasing angler awareness of conservation, have resulted in the vast majority …
An Evaluation Of A Reduced Bar Spacing Turtle Excluder Device In The U.S Gulf Of Mexico Offshore Shrimp Trawl Fishery, Michel Anthony Nalovic
An Evaluation Of A Reduced Bar Spacing Turtle Excluder Device In The U.S Gulf Of Mexico Offshore Shrimp Trawl Fishery, Michel Anthony Nalovic
Dissertations, Theses, and Masters Projects
Shrimp are the most economically valuable internationally-traded seafood commodity, and wild-caught, trawled shrimp make up almost half of the ~6.6 million metric tons of annual global production. Shrimp trawling is responsible for one-third of the world’s total fisheries bycatch, leading many to consider shrimp trawling to be the single most destructive fishing practice in the world. Though the bycatch of large marine animals can be significantly reduced by use of turtle excluder devices (TEDs) on shrimp trawls, current TED designs are ineffective at reducing the capture of smaller organisms which represent a large portion of the total bycatch. To further …
Fishes In Seagrass Habitats: Species Composition, Trophic Interactions, And Production, Kathryn L. Sobocinski
Fishes In Seagrass Habitats: Species Composition, Trophic Interactions, And Production, Kathryn L. Sobocinski
Dissertations, Theses, and Masters Projects
The value of habitats in terms of biological production is of interest to ecologists and resource managers. Seagrasses are a commonly occurring habitat type in shallow marine waters and have been shown to support high abundances of fish and invertebrates. In lower Chesapeake Bay, seagrasses grow in a shallow fringe in the subtidal zone. Although, ample evidence exists for the value of these habitats as foraging and rearing areas for a variety of organisms, the connectivity among species and the benefits derived from these habitats in terms of production have not been well described, especially for small, seasonally occurring finfishes. …
Factors Influencing Year-Class Strength And Growth Of Young-Of-The-Year Summer Flounder (Paralichthyidae: Paralichthys Dentatus), Lauren N. Nys
Factors Influencing Year-Class Strength And Growth Of Young-Of-The-Year Summer Flounder (Paralichthyidae: Paralichthys Dentatus), Lauren N. Nys
Dissertations, Theses, and Masters Projects
No abstract provided.
Post-Release Mortality Of School-Size Atlantic Bluefin Tuna (Thunnus Thynnus) In The U.S Recreational Troll Fishery, Benjamin Jon Marcek
Post-Release Mortality Of School-Size Atlantic Bluefin Tuna (Thunnus Thynnus) In The U.S Recreational Troll Fishery, Benjamin Jon Marcek
Dissertations, Theses, and Masters Projects
Atlantic bluefin tuna Thunnus thynnus (ABFT) support commercial and recreational fisheries throughout the North Atlantic Ocean. Due to heavy fishing pressure over the course of several decades, the eastern and western stocks of ABFT were overfished and the current biomass of the western stock is estimated to be approximately 19% of the biomass necessary for maximum sustainable yield. Despite a variety of management measures, including the implementation of minimum sizes and reductions of the total allowable catch (TAC) and country-specific quotas, little change was observed in the status of the western stock. The U.S. commercial and recreational ABFT fisheries are …
Seasonal Nitrogen Uptake And Regeneration In The Water Column And Sea-Ice Of The Western Coastal Arctic, Steven E. Baer
Seasonal Nitrogen Uptake And Regeneration In The Water Column And Sea-Ice Of The Western Coastal Arctic, Steven E. Baer
Dissertations, Theses, and Masters Projects
The logistical difficulties of research in extremely low temperatures and lack of access to the Arctic have meant that there is a historic dearth of knowledge of coastal Arctic biogeochemistry, especially during winter when sea ice is present. Recent observations, however, indicate that the Arctic is changing rapidly. Changes include increased temperatures, decreased extent and volume of sea ice, and increased freshwater inputs. How these changes influence biogeochemical cycles is an open question, especially in the highly productive coastal regions of the Chukchi Sea. Here I present nitrogen (N) uptake and regeneration rates for phytoplankton and bacteria measured in the …
The Development Of Ecological Functions In Created Forested Wetlands, Sean P. Charles
The Development Of Ecological Functions In Created Forested Wetlands, Sean P. Charles
Dissertations, Theses, and Masters Projects
Wetland mitigation has become a 2.4 billion dollar per year industry in the U.S. and in Virginia it leads to the replacement of 77 ha of palustrine forested wetlands (PFWs) per year with mitigation wetlands, including created forested wetlands (CFWs). Mitigation hinges on the idea that compensation wetlands lead to “no net loss of wetland function” when compared to impacted wetlands. We assessed the functions of provision of habitat and biogeochemical functions associated with production of biomass, the retention and removal of nutrients and the accumulation of soil C over 8 years in seven CFWs of approximately 11 and 20 …
Distribution And Impacts Of Invasive Bivalve Corbicula Fluminea In Tidal Freshwater York River Tributaries, Matthew Ryan Freedman
Distribution And Impacts Of Invasive Bivalve Corbicula Fluminea In Tidal Freshwater York River Tributaries, Matthew Ryan Freedman
Dissertations, Theses, and Masters Projects
The Asian clam, Corbicula fluminea, is one of the most invasive bivalves in the world but there is limited research on its presence in tidal freshwater systems. Despite its introduction into Chesapeake Bay tributaries in the 1970s, the initial colonization and subsequent development of populations of C. fluminea in the Mattaponi and Pamunkey sub-tributaries of the York River, Virginia, is mostly undocumented. This study assessed the spatial distribution and population structure of C. fluminea in tidal freshwater sections of these rivers (~45km) with benthic surveys during summer 2011 – 2012. Benthic grabs (2.4L, 0.023m2) taken at 40 sites in each …
Improvements In Triploid Crassostrea Virginica Production: Characterizing The Diploid Parent, Brian R. Callam
Improvements In Triploid Crassostrea Virginica Production: Characterizing The Diploid Parent, Brian R. Callam
Dissertations, Theses, and Masters Projects
The effect of triploidy to effect faster growth and increased survival compared to diploid oysters is called the ‘triploid advantage’ and this advantage in the Chesapeake Bay for Crassostrea virginica is the principal reason for the value of triploid C. virginica in the Chesapeake Bay, USA. The triploid advantage is hypothesized to be the result of genetic effects, physiological changes, or a combination of both. The causative genetic mechanisms at play may include additive genetic effects and heterosis while the physiological changes obtain from triploid sterility. The triploid advantage was examined by comparing 13 diploid and 13 triploid crosses across …
Foraging Ecology And Habitat Use Of The Northern Diamondback Terrapin (Malaclemys Terrapin Terrapin) In Southern Chesapeake Bay, Diane C. Tulipani
Foraging Ecology And Habitat Use Of The Northern Diamondback Terrapin (Malaclemys Terrapin Terrapin) In Southern Chesapeake Bay, Diane C. Tulipani
Dissertations, Theses, and Masters Projects
The northern diamondback terrapin (Malaclemys terrapin ) is the only estuarine turtle residing along western Atlantic and Gulf of Mexico coasts of North America. Through predation, terrapins may be a key species in coastal marine habitats by exerting top-down control on marsh invertebrates, and thereby help to maintain healthy marshes. Despite the terrapin's ecological importance, there has not been a thorough study of terrapin foraging ecology and movements in lower Chesapeake Bay. In this dissertation, the research focused on the foraging habits of diamondback terrapins and their effects within salt marsh and seagrass habitats of lower Chesapeake Bay. I provided …
Food Availability And Utilization For Cultured Hard Clams, Richard Garrik Secrist
Food Availability And Utilization For Cultured Hard Clams, Richard Garrik Secrist
Dissertations, Theses, and Masters Projects
Aquaculture of the hard clam Mercenaria mercenaria is a valuable industry on the east coast. At high planting densities, cultured bivalves can become limited by food availability, resulting in reduced growth. Centric diatoms are considered the dominant food source to cultured bivalves. Alternative sources may also be important, including resuspended benthic microalgae (pennate diatoms) and detritus from macroalgae growing on predator exclusion nets. This study measured (1) the availability of different food sources in clam beds at Cherrystone Inlet in Chesapeake Bay, including the effects of macroalgae on food availability, and (2) the clearance rates and absorption efficiencies by cultured …
Interannual And Regional Differences In Krill And Fish Prey Quality Along The Western Antarctic Peninsula, Kate E. Ruck
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
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 …
Patterns Of Population Structure And Historical Dispersal In Squaloid Sharks: A Species-Level Approach Using Molecular Markers, Ana Christina Pimenta Verissimo
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 …
Habitat Utilization And Trophic Interactions By Fauna In A Shallow Estuary: Comparisons Between Clam Aquaculture And Natural Sites, Lara Gates Kling
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 …
Effects Of Life History And Physical Variables On Winter Distribution Of Blue Crabs In Chesapeake Bay, Gabrielle G. Saluta
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.
Life History And Ecology Of The Freshwater Amphipods Gammarus Pseudolimnaeus And Gammarus Fasciatus In Southeastern Virginia, Lindsey L. Postaski
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.
Rogue Fishermen: Codfish, Atlantic Items, And The Isles Of Shoals, Megan Victor
Rogue Fishermen: Codfish, Atlantic Items, And The Isles Of Shoals, Megan Victor
Dissertations, Theses, and Masters Projects
No abstract provided.