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Contributions To The Life History Of Juvenile Blueback Herring (Alosa Aestivalis): Phototactic Behavior And Population Dynamics, Douglas A. Dixon Jan 1996

Contributions To The Life History Of Juvenile Blueback Herring (Alosa Aestivalis): Phototactic Behavior And Population Dynamics, Douglas A. Dixon

Dissertations, Theses, and Masters Projects

This research investigated the relationship between juvenile abundance indexes (JAIs) for anadromous blueback herring (Alosa aestivalis) and abiotic factors (river flow and temperature) during the spawning and nursery period in the tidal freshwater areas of James, Pamunkey, Mattaponi, and Rappahannock Rivers in Virginia. Accomplishing this objective required the evaluation of the JAI methodology, specifically the effect of phototactic behavior on diel changes in the surface availability to the pushnet sampling gear, and obtaining population dynamics information (hatch dates, growth, natural mortality) during early life history from otolith microstructure of samples collected in 1991 and 1992. Mean catch-per-unit effort (CPUE) at ...


Subadult Loggerhead Sea Turtle (Caretta Caretta) Behavior In St. Mary's Entrance Channel, Georgia, United States, David A. Nelson Jan 1996

Subadult Loggerhead Sea Turtle (Caretta Caretta) Behavior In St. Mary's Entrance Channel, Georgia, United States, David A. Nelson

Dissertations, Theses, and Masters Projects

A study of channel utilization and behavior of subadult loggerhead turtles was conducted in the St. Mary's River entrance channel area, Georgia. A total of 38 loggerheads were captured by trawling and instrumented with radio and depth sensitive sonic tags from April to November 1993. Turtles were monitored for 6 to 36 hours continuously for approximately 30 days in the spring (13), summer (13), and fall (14). On a daily basis turtles generally confined their diving activity to one location for one to twelve hours in 10 to 20 m water depths then moved 1 to 5 kilometers to ...


The Role Of Microbial Food Webs In Benthic-Pelagic Coupling In Freshwater And Marine Ecosystems, Adele J. Pile Jan 1996

The Role Of Microbial Food Webs In Benthic-Pelagic Coupling In Freshwater And Marine Ecosystems, Adele J. Pile

Dissertations, Theses, and Masters Projects

A majority of carbon in freshwater and marine ecosystems is in the form of ultraplankton, heterotrophic and autotrophic plankton &<&5 &\mu&m including heterotrophic bacteria, Prochlorococcus, cyanobacteria, and autotrophic eucaryotes. However, ultraplankton and subsequently microbial food webs have yet to be incorporated into models of benthic-pelagic coupling despite the preponderance of macroinvertebrates with the capacity to feed on ultraplankton. I have examined the role of microbial food webs in benthic-pelagic coupling in three ecosystems: Lake Baikal, Siberia, Russia; Gulf of Maine, Northwest Atlantic Ocean; and Conch Reef, Florida Keys, USA. Using sponges as a model organism and in situ measurements, I have quantified (1) suspension feeding on ultraplankton and (2) release of dissolved inorganic nitrogen (DIN) and phosphorus (DIP) resulting in direct evidence that benthic macroinvertebrates do occupy the level of primary consumer within the microbial food web. Dual-beam flow cytometry was employed to quantified sponge suspension feeding on five types of ultraplankton: heterotrophic bacteria, Synechococcus-type cyanobacteria, autotrophic picoplankton &<&3 &\mu&m, autotrophic eucaryotes 3-10 &\mu&m, and in marine ecosystems Prochlorococcus. Grazing by the freshwater sponges Baikalospongia intermedia and B. bacilliferia and the boreal marine sponge, Mycale lingua, was unselective for all types of ultraplankton with efficiencies ranging from 63-99%. This is the first time that grazing on Synechococcus-type cyanobacteria and Prochlorococcus by macroinvertebrates has been quantified in freshwater and marine ecosystems. Conversely, the coral reef sponges Ircinia felix and I. strobilina release significant amounts of DIN and DIP as a result of grazing on procaryotic plankton. Using a general model for organism-mediated fluxes, it is conservatively estimated that through active suspension feeding sponges in Lake Baikal retain 1.97 g C day&\sp{lcub}-1{rcub}& m&\sp{lcub}-2{rcub}& and M. lingua retains 29 mg C day&\sp{lcub}-1{rcub}& m&\sp{lcub}-2{rcub}& while at Conch Reef sponges released 204 &\mu&mol DIN day&\sp{lcub}-1{rcub}& m&\sp{lcub}-2{rcub}& and 48 &\mu&mol DIP day&\sp{lcub}-1{rcub}& m&\sp{lcub}-2{rcub}&. A majority of the carbon retained at all three locations was from procaryotic cell types suggesting that ultraplankton are an important overlooked component of benthic-pelagic coupling.


Reproductive Biology Of Tautog, Tautoga Onitis, In The Lower Chesapeake Bay And Coastal Waters Of Virginia, Geoffrey Gordon White Jan 1996

Reproductive Biology Of Tautog, Tautoga Onitis, In The Lower Chesapeake Bay And Coastal Waters Of Virginia, Geoffrey Gordon White

Dissertations, Theses, and Masters Projects

No abstract provided.


The Development Of Affinity Maturation In Rainbow Trout Oncorhynchus Mykiss, Ing Wei Khor Jan 1996

The Development Of Affinity Maturation In Rainbow Trout Oncorhynchus Mykiss, Ing Wei Khor

Dissertations, Theses, and Masters Projects

No abstract provided.


Lipid Class Composition Of Oysters, Crassostrea Virginica, Exposed To Sediment-Associated Pahs, Tong Li Jan 1996

Lipid Class Composition Of Oysters, Crassostrea Virginica, Exposed To Sediment-Associated Pahs, Tong Li

Dissertations, Theses, and Masters Projects

No abstract provided.


Autoecology Of Paraprionospio Pinnata (Polychaeta: Spionide) Along An Estuarine Gradient, Elizabeth K. Hinchey Jan 1996

Autoecology Of Paraprionospio Pinnata (Polychaeta: Spionide) Along An Estuarine Gradient, Elizabeth K. Hinchey

Dissertations, Theses, and Masters Projects

No abstract provided.


Altered Expression Of A Glutathione S-Transferase Isoform In Creosote-Resistant Mummichog, Fundulus Heteroclitus, Susan Lovejoy Armknecht Jan 1996

Altered Expression Of A Glutathione S-Transferase Isoform In Creosote-Resistant Mummichog, Fundulus Heteroclitus, Susan Lovejoy Armknecht

Dissertations, Theses, and Masters Projects

No abstract provided.


Perkinsus Marinus Extracellular Proteases: Modulation Of Production By Environmental Factors And Effects On The Host Defense Parameters Of The Eastern Oyster Crassostrea Virginica, Kathleen A. Garreis Jan 1996

Perkinsus Marinus Extracellular Proteases: Modulation Of Production By Environmental Factors And Effects On The Host Defense Parameters Of The Eastern Oyster Crassostrea Virginica, Kathleen A. Garreis

Dissertations, Theses, and Masters Projects

No abstract provided.


Growth Dynamics Of A York River Estuary Heterotrophic Dinoflagellate Grazing Katodinium Rotundatum, Angela Denise Smith Jan 1996

Growth Dynamics Of A York River Estuary Heterotrophic Dinoflagellate Grazing Katodinium Rotundatum, Angela Denise Smith

Dissertations, Theses, and Masters Projects

No abstract provided.


Potential For Population Regulation Of The Zebra Mussel, Dreissena Polymorpha, In The Hudson River, Larry C. Boles Jan 1996

Potential For Population Regulation Of The Zebra Mussel, Dreissena Polymorpha, In The Hudson River, Larry C. Boles

Dissertations, Theses, and Masters Projects

No abstract provided.


Evaluating The Genotoxicity Of Quinacrine In Mammals Using The Sister Chromatid Exchange Test, Sutapa Ray Jan 1996

Evaluating The Genotoxicity Of Quinacrine In Mammals Using The Sister Chromatid Exchange Test, Sutapa Ray

Dissertations, Theses, and Masters Projects

No abstract provided.


Breeding Ecology, Success, And Population Management Of The Piping Plover (Charadrius Melodus) At Chincoteague National Wildlife Refuge, Virginia, Robert Richard Cross Jan 1996

Breeding Ecology, Success, And Population Management Of The Piping Plover (Charadrius Melodus) At Chincoteague National Wildlife Refuge, Virginia, Robert Richard Cross

Dissertations, Theses, and Masters Projects

No abstract provided.


Preferences Of Female Peromyscus Maniculatus Bairdii For Proximity To Males: Implications For The Evolution Of The Bruce Effect, Tavis Winton Sipe Jan 1996

Preferences Of Female Peromyscus Maniculatus Bairdii For Proximity To Males: Implications For The Evolution Of The Bruce Effect, Tavis Winton Sipe

Dissertations, Theses, and Masters Projects

No abstract provided.


Schizotypy And Extroversion-Introversion: Correlation And Electrodermal Activities In Emotions, Kai Qu Jan 1996

Schizotypy And Extroversion-Introversion: Correlation And Electrodermal Activities In Emotions, Kai Qu

Dissertations, Theses, and Masters Projects

No abstract provided.


Neuropsychological Function, Recidivism, And Community Adjustment Of The Mentally Ill Chemically Addicted (Mica) Patient, Robert Warren Smith Jan 1996

Neuropsychological Function, Recidivism, And Community Adjustment Of The Mentally Ill Chemically Addicted (Mica) Patient, Robert Warren Smith

Dissertations, Theses, and Masters Projects

No abstract provided.


Integrative Analysis Of Ecosystem Processes In The Littoral Zone Of Lower Chesapeake Bay: A Modeling Study Of The Goodwin Islands National Estuarine Research Reserve, Christopher P. Buzzelli Jan 1996

Integrative Analysis Of Ecosystem Processes In The Littoral Zone Of Lower Chesapeake Bay: A Modeling Study Of The Goodwin Islands National Estuarine Research Reserve, Christopher P. Buzzelli

Dissertations, Theses, and Masters Projects

Approximately 40% of the bottom of Chesapeake Bay is less than 2.0 m in depth and many of these broad shoal environments are bordered by wetlands. The vegetated and nonvegetated subtidal and intertidal environment is a dynamic mosaic of highly productive estuarine habitats linked by the exchange of waterborne materials. This study developed simulation models of primary production and material exchange for four littoral zone habitats of the Goodwin Islands National Estuarine Research Reserve (NERR) in lower Chesapeake Bay. Field studies were conducted to determine the sediment biogeochemical and biomass characteristics of sandy shoal, seagrass, silt-mud, and marsh habitats ...


Expression Of The Xenobiotic Transporter P-Glycoprotein In The Mummichog (Fundulus Heteroclitus), Peter S. Cooper Jan 1996

Expression Of The Xenobiotic Transporter P-Glycoprotein In The Mummichog (Fundulus Heteroclitus), Peter S. Cooper

Dissertations, Theses, and Masters Projects

The mammalian mdr1 P-glycoprotein (Pgp) has been implicated in xenobiotic resistance of drug-resistant cell lines and tumors, and may function in excretion or exclusion of toxic xenobiotics at several sites within the body. Pgp gene family members are expressed in excretory epithelia of several aquatic taxa and may contribute to the survival of pollution-tolerant aquatic animals in contaminated environments. For this reason the expression of Pgp family members was investigated in the livers and liver tumors of creosote-resistant mummichog (Fundulus heteroclitus) inhabiting a creosote-contaminated site (Atlantic Wood) in the Elizabeth River, Virginia. Expression of members of the Pgp gene family ...


Demersal Predator Exposure To Toxic Organic Contaminants: Direct Effects Of Macrofauna In Trophic Transfer, Patrick Winfield Lay Jan 1996

Demersal Predator Exposure To Toxic Organic Contaminants: Direct Effects Of Macrofauna In Trophic Transfer, Patrick Winfield Lay

Dissertations, Theses, and Masters Projects

The bioaccumulation and metabolism of organic contaminants (PAH, PCB) by three estuarine polychaetes, Nereis succinea (Frey and Leuckart 1847), Paraprionospio pinnata (Ehlers 1901) and Polydora ligni (Webster 1879), and by the fish predator, spot (Leiostomus xanthurus Lacepede 1802), were examined in laboratory experiments. Variations in trophic transfer of these contaminants resulting from differences in prey and contaminant type were also investigated. Toxicokinetic modeling reveals that metabolism of organic contaminants by invertebrate species result in variations in uptake, metabolism and elimination rate constants. Incorporation of prey metabolism potential in kinetic models increases the latter's predictability of biota-sediment accumulation factors (BSAFs ...


The Role Of Epibenthic Predators In Structuring Marine Soft-Bottom Communities Along An Estuarine Gradient, Rochelle D. Seitz Jan 1996

The Role Of Epibenthic Predators In Structuring Marine Soft-Bottom Communities Along An Estuarine Gradient, Rochelle D. Seitz

Dissertations, Theses, and Masters Projects

A unifying theory of community regulation in soft-bottom systems remains elusive, despite extensive field studies on factors controlling community structure. Here, I have (1) reviewed models of community regulation, (2) examined the role of predation in controlling benthic diversity along a salinity gradient, (3) examined effects of predation upon an abundant bivalve, Macoma balthica, and (4) revised a model of community regulation in an estuarine soft-bottom system. The Menge and Sutherland (MS) "consumer stress model" posits that consumers feed ineffectively in harsh environments, and the importance of physical disturbance, competition and predation varies with recruitment, environmental conditions, and trophic position ...


Reproductive Biology Of Spanish Mackerel, Scomberomorus Maculatus, In The Lower Chesapeake Bay, Cynthia L. Cooksey Jan 1996

Reproductive Biology Of Spanish Mackerel, Scomberomorus Maculatus, In The Lower Chesapeake Bay, Cynthia L. Cooksey

Dissertations, Theses, and Masters Projects

Spanish mackerel were purchased from commercial fisheries in the Chesapeake Bay in the period 1993-1994 and processed for biological data to describe reproductive biology. Spanish mackerel are multiple spawners with asynchronous oocyte development and indeterminate fecundity. They spawn in the Chesapeake Bay area from June through August, June being the peak spawning month. Individuals, however, vary greatly in when they begin and end spawning. The presence of Gravid and Running Ripe females indicates spawning inside the Chesapeake Bay, and the capture of small juveniles suggests the region may be used as a nursery grounds. Sex ratios vary greatly, females generally ...


Effects Of Periodic Environmental Hypoxia On Predator Utilization Of Macrobenthic Infauna, Janet A. Nestlerode Jan 1996

Effects Of Periodic Environmental Hypoxia On Predator Utilization Of Macrobenthic Infauna, Janet A. Nestlerode

Dissertations, Theses, and Masters Projects

Hypoxia and anoxia have significant deleterious ecological effects on living resources throughout many estuarine and marine ecosystems worldwide. Brief periods of low oxygen facilitate transfer of benthic production to higher trophic levels as many benthic infaunal species have shallower sediment depth distributions during hypoxic events. A baited time-lapse camera equipped with a water quality datalogger was used to document in situ exploitation of oxygen-stressed benthic invertebrate prey organisms by mobile fish and crustacean predators during alternating normoxia-hypoxia cycles in the York River. Based on photographic and diver observations, this hypoxiainduced benthic-pelagic transfer of production is more likely to occur when ...


Age, Growth, And Reproductive Biology Of Blackcheek Tonguefish, Symphurus Plagiusa (Cynoglossidae: Pleuronectiformes), In Chesapeake Bay, Virginia, Mark Richard Terwilliger Jan 1996

Age, Growth, And Reproductive Biology Of Blackcheek Tonguefish, Symphurus Plagiusa (Cynoglossidae: Pleuronectiformes), In Chesapeake Bay, Virginia, Mark Richard Terwilliger

Dissertations, Theses, and Masters Projects

No abstract provided.


Habitat Complexity As A Determinant Of Juvenile Blue Crab Survival, Jessica L. Schulman Jan 1996

Habitat Complexity As A Determinant Of Juvenile Blue Crab Survival, Jessica L. Schulman

Dissertations, Theses, and Masters Projects

No abstract provided.


A Study Of The Effect Of Interactive Language In The Stimulation Of Cognitive Functioning For Students With Learning Disabilities, Kathleen Ricards Hopkins Jan 1996

A Study Of The Effect Of Interactive Language In The Stimulation Of Cognitive Functioning For Students With Learning Disabilities, Kathleen Ricards Hopkins

Dissertations, Theses, and Masters Projects

Much can be gained by applying knowledge and insight gleaned from the field of neuropsychology to the field of education. Diagnosis and treatment of learning disabilities (LD) could be enhanced through an increased understanding of neurolinguistic functioning. The present study examined the effect of five instructional techniques aimed at stimulating the cognitive functioning of students with diagnosed learning disabilities. The defining characteristic of each of the five techniques is the use of interactive dialogue to stimulate oral language production leading to greater cognitive efficiency. Evidence is presented for the need for interhemispheric collaboration in complex linguistic tasks such as reading ...


The Impact Of Sick Building Syndrome On Selected Variables Associated With School Effectiveness, Caryl Shannon Felty Jan 1996

The Impact Of Sick Building Syndrome On Selected Variables Associated With School Effectiveness, Caryl Shannon Felty

Dissertations, Theses, and Masters Projects

Using matched pairs of schools having a diagnosis of Sick Building Syndrome (SBS) and those not identified, and not having the potential of being identified as having the diagnosis, this study examined the relationship between factors assumed or determined to have an impact on a school's ability to carry out its mission as they related to the SBS diagnosis. The factors studied were student average daily attendance (ADA); students' mean standardized test scores in math and reading on the Iowa Test of Basic Skills and the Tests of Achievement and Proficiency; the need for students to take prophylactic medications ...


The Influence Of Location, Seagrass Species And Water Depth On The Settlement And Distribution Of Early Stage Blue Crabs, Renee A. Pardieck Jan 1996

The Influence Of Location, Seagrass Species And Water Depth On The Settlement And Distribution Of Early Stage Blue Crabs, Renee A. Pardieck

Dissertations, Theses, and Masters Projects

No abstract provided.


Field And Laboratory Evidence Of Pheromone Mediated Mating Behavior In The Blue Crab, Callinectes Sapidus, Donald S. Gibbs Jan 1996

Field And Laboratory Evidence Of Pheromone Mediated Mating Behavior In The Blue Crab, Callinectes Sapidus, Donald S. Gibbs

Dissertations, Theses, and Masters Projects

No abstract provided.


Phylogeny Of The Haplosporidia (Eukaryota: Alveolata) Based On Small Subunit Ribosomal Rna Gene Sequence, Brenda Sandy Flores Jan 1996

Phylogeny Of The Haplosporidia (Eukaryota: Alveolata) Based On Small Subunit Ribosomal Rna Gene Sequence, Brenda Sandy Flores

Dissertations, Theses, and Masters Projects

No abstract provided.


Guided Imagery As A Psychoneuroimmunological Intervention For Hiv-Positive Individuals, Christopher Dale Keene Jan 1996

Guided Imagery As A Psychoneuroimmunological Intervention For Hiv-Positive Individuals, Christopher Dale Keene

Dissertations, Theses, and Masters Projects

No abstract provided.