Ecology and Evolutionary Biology Commons^™

Modeling Habitat And Environmental Factors Affecting Mosquito Abundance In Chesapeake, Virginia, Alan Scott Bellows

Biological Sciences Theses & Dissertations

The models I present in this dissertation were designed to enable mosquito control agencies in the mid-Atlantic region that oversee large jurisdictions to rapidly track the spatial and temporal distributions of mosquito species, especially those species known to be vectors of eastern equine encephalitis and West Nile virus. I was able to keep these models streamlined, user-friendly, and not cost-prohibitive using empirically based digital data to analyze mosquito-abundance patterns in real landscapes.

This research is presented in three major chapters: (II) a series of semi-static habitat suitability indices (HSI) grounded on well-documented associations between mosquito abundance and environmental variables, (III) …

Molecular Phylogenetics Of Perciform Fishes Using The Nuclear Recombination Activating Gene 1, Andrew R. Mahon

Biological Sciences Theses & Dissertations

The order Perciformes contains one-third of all extant fishes in twenty different suborders and over 10,000 species. Few systematic investigations have been performed on this large group of fishes at the suborder level and their evolutionary history is widely recognized as problematic. This dissertation presents three studies: a molecular phylogenetic analysis of the putative suborders of the order Perciformes, an analysis of interrelationships of the families of the perciform suborder Percoidei, and a multi-gene investigation of the percoid superfamily Sparoidea.

The taxa sampled in this dissertation represent one of the most inclusive molecular datasets, to date, testing the monophyly of …

Behavioral Enhancement Of Onshore Transport By Postlarval Caribbean Spiny Lobster (Panulirus Argus), Jason Seth Goldstein

Biological Sciences Theses & Dissertations

The onshore transport of meroplanktonic marine larvae or postlarvae is often complex, involving both active (i.e., behavior, swimming) and passive (i.e., oceanographic elements) transport mechanisms. Behaviors that modify passive transport have presumably evolved to situate larvae in settlement habitats where survival is enhanced. Active transport mechanisms have not been described for the puerulus postlarvae of any species of spiny lobster, despite their extraordinary mobility and known preference for specific settlement habitats. In the Florida Keys, for example, Caribbean spiny lobster (Panulirus argus) pueruli travel from oceanic waters into coastal areas where they settle within bushy, red macroalgae. I …

Effects Of Elevated Atmospheric Co2 On Root Dynamics, Biomass And Architecture In A Scrub-Oak Ecosystem At Kennedy Space Center, Florida, Daniel Benjamin Stover

Biological Sciences Theses & Dissertations

A major gap in whole-plant ecology lies with our understanding of root system growth, function and distribution. Large belowground structures, in addition to fine roots, are of particular interest because of their role in carbon sequestration. Non-destructive methods, including ground-penetrating radar (GPR) and minirhizotron observation tubes, were used to investigate effects of elevated CO₂ on root biomass, dynamics (productivity, mortality, and turnover), root persistence and architecture in a fire dominated scrub-oak ecosystem. Open-top chambers have been exposed to elevated atmospheric CO₂ for the past eleven years at Kennedy Space Center, Florida. No significant sustained CO₂ treatment effects …

Stormwater Influence On Phytoplankton Composition And Dynamics In Lake Joyce, Virginia, Lewis F. Affronti Jr., B. Thomas Duquette

Virginia Journal of Science

A three year study of Lake Joyce, Virginia revealed relationships between the timing, duration, and amount of stormwater runoff and phytoplankton abundance and composition. Major phytoplankton taxa were identified and cyanophytes dominanted during periods of decreased rainwater input and increased lake water retention times. Increased freshwater input was associated with the growth of a diverse assemblage of both chlorophytes and diatoms. Phytoplankton dynamics as a result of significant rain events (i.e., hurricanes Floyd and Irene, 1999) were documented and specific taxa involved in nuisance algal blooms were identified.

Current Status And Long-Term Trends In Water Quality And Living Resources In The Virginia Tributaries And Chesapeake Bay Mainstem From 1985 Through 2005, Daniel M. Dauer, Harold G. Marshall, John R. Donat, Michael F. Lane, Suzanne C. Doughten, Frederick A. Hoffman

Status and Trends for Virginia Chesapeake Bay

A marked decline in the water quality of the Chesapeake Bay has occurred over the past several decades. The disappearance of submerged aquatic vegetation in certain regions of the Bay, declines in the abundance of some commercially and recreationally important species, increases in the incidence of low dissolved oxygen events, changes in the Bay's food web, and other ecological problems have been related to the deteriorating water quality. The results of concentrated research efforts in the late 1970s and early 1980s stimulated the establishment of Federal and state directives to better manage the Chesapeake Bay watershed. By way of the …

Plant Assemblage Structure On Barrier Island ‘Pimple’ Dunes At The Virginia Coast Reserve Long-Term Ecological Research Site, Brett A. Mcmillan

Biological Sciences Theses & Dissertations

The habitats at the VCR LTER that were the focus of the current study are the Hog Island and Parramore Island 'pimples', small, rounded dunes forming along main dune ridges of the barrier islands. There are distinct plant assemblage zones found on pimples, although most of these dunes are 10–20 m in diameter. Hypotheses of the study were that fresh water availability was a main determinant of differences between assemblages and that pimple size and location would influence diversity and assemblage structure. Research goals were (1) to describe the plant assemblages on pimples, (2) to relate edaphic and geomorphological factors …

Phytoplankton Productivity In The Tidal Regions Of Four Chesapeake Bay (U.S.A.) Tributaries, Kneeland K. Nesius, Harold G. Marshall, Todd A. Egerton

Virginia Journal of Science

Monthly and annual phytoplankton productivity rates of four Virginia tidal rivers were determined based on a 12-year monitoring study that included sampling stations from tidal freshwater, oligohaline, and mesohaline regions in these rivers. The mean monthly rates and range at these locations were 5.52 (Dec.) to 175.12 (Aug.) mg C m^-3 h^-1 for tidal freshwater, 12.21 (Jan.) to 149.90 (May) mg C m^-3 h^-1 in oligohaline regions, and 16.20 (Jan.) to 151.33 (May) mg C m^-3 h^-1 for the mesohaline. The estimated mean annual 12 year productivity for the different Virginia river sites in …

Termite Resource Partitioning Related To Log Diameter, Deborah A. Waller

Biological Sciences Faculty Publications

The termites Reticuliterines virginicus and R. flavipes are sympatric in forests along the eastern United States from Florida to Maryland. These congeners construct subterranean nests, forage on surface and buried wood, and appear to have very similar ecological requirements. In the present study, I examined host-wood selection by these species in a coastal forest over two years. Logs inhabited by R. virginicus had significantly greater diameters than those used by R. flavipes. It is not known whether this pattern resulted from species-specific differences in preference for host size or competition for preferred logs. Host-wood temperature did not differ for …

Sensory Genes And Mate Choice: Evidence That Duplications, Mutations, And Adaptive Evolution Alter Variation In Mating Cue Genes And Their Receptors, Lisa Horth

Biological Sciences Faculty Publications

Fascinating new data, revealed through gene sequencing, comparative genomics, and genetic engineering, precisely establish which genes are involved in mate choice and mating activity—behaviors that are surprisingly understudied from a genetic perspective. Discussed here are some of the recently identified visual and chemosensory genes that are involved in mate choice and mating behavior. These genes’ products are involved in the production, transmission, and receipt of crucial sensory mate-choice cues that affect fitness. This review exposes newfound evidence that alternative splicing, gene-expression pattern changes, and molecular genetic variation in sensory genes are crucial for both intra- and interspecific mate choice and …

Bottom-Up Forcing And The Decline Of Steller Sea Lions (Eumetopias Jubatus) In Alaska: Assessing The Ocean Climate Hypothesis, Andrew W. Trites, Arthur J. Miller, Michael A. Alexander, Steven J. Bograd, John A. Calder, Antonietta Capotondi, Kenneth O. Coyle, Emanuele Di Lorenzo, Bruce P. Finney, Edward J. Gregr, Chester E. Grosch, Thomas C. Royer

CCPO Publications

Declines of Steller sea lion ( Eumetopias jubatus) populations in the Aleutian Islands and Gulf of Alaska could be a consequence of physical oceanographic changes associated with the 1976–77 climate regime shift. Changes in ocean climate are hypothesized to have affected the quantity, quality, and accessibility of prey, which in turn may have affected the rates of birth and death of sea lions. Recent studies of the spatial and temporal variations in the ocean climate system of the North Pacific support this hypothesis. Ocean climate changes appear to have created adaptive opportunities for various species that are preyed upon …

Response Of Eelgrass Zostera Marina To Co2 Enrichment: Possible Impacts Of Climate Change And Potential For Remediation Of Coastal Habitats, Sherry L. Palacios, Richard C. Zimmerman

OES Faculty Publications

Projected increases in dissolved aqueous concentrations of carbon dioxide [CO_2(aq)] may have significant impacts on photosynthesis Of CO₂-limited organisms such as seagrasses. Short-term CO_2(aq) enrichment increases photosynthetic rates and reduces light requirements for growth and survival of individual eelgrass Zostera marina L. shoots growing in the laboratory under artificial light regimes for at least 45 d. This study examined the effects of long-term CO_2(aq) enrichment on the performance of eelgrass growing under natural light-replete (33% surface irradiance) and light-limited (5% surface irradiance) conditions for a period of 1 yr. Eelgrass shoots were grown at …

Benthic Biological Monitoring Program Of The Elizabeth River Watershed (2005), Daniel M. Dauer

Elizabeth River Reports

Executive Summary

Macrobenthic communities of the Elizabeth River watershed have been quantitatively sampled since summer 1999. This report presents the data from the seventh year of sampling in 2005. The three objectives of the Benthic Biological Monitoring Program of the Elizabeth River watershed are: (1) To characterize the health of the tidal waters of the Elizabeth River watershed as indicated by the structure of the benthic communities. (2) To conduct trend analyses on long-term data at 14 fixed-point stations to relate temporal trends in the benthic communities to changes in water and/or sediment quality. Trend analyses will be updated annually …

Chemical Evidence For Dietary Toxin Sequestration In The Asian Snake Rhabdophis Tigrinus, Deborah A. Hutchinson

Biological Sciences Theses & Dissertations

Rhabdophis tigrinus (Colubridae: Natricinae) is an oviparous, bufophagous (toad-eating) snake from eastern Asia that possesses defensive integumentary glands on the neck known as nuchal glands. These glands are used in antipredator displays and typically contain bufadienolide toxins. Whereas toads are known to synthesize bufadienolide steroids from cholesterol precursors, we found that chemically undefended R. tigrinus must sequester bufadienolides from ingested toads in order to exhibit these compounds in their nuchal glands. Chemically defended females are capable of provisioning their embryos with these toxins so their unfed hatchlings possess defensive bufadienolides prior to consuming toads themselves. All of the hatchling R. …

An Examination Of Seasonal Growth And Survivorship Of Sigmodon Hispidus In Southeastern Virginia, Heather Alyssa Green

Biological Sciences Theses & Dissertations

A reexamination of specific population dynamic aspects of Sigmodon hispidus, the hispid cotton rat, is necessary in order to gain additional knowledge and perspective on this species in its northernmost distribution on the east coast of the United States. Previous studies of Virginia cotton rats were based on data from necropsies, which do not allow for the determination of certain population characteristics, such as density, growth, and survival. General population trends and rates of growth and survival in males and females throughout the seasons in Virginia will also provide a basis for comparison with populations of cotton rats in …

Effects Of Elevated Atmospheric Co₂ On Scrub-Oak Root Carbon Pools And Soil Microbial Processes, Alisha Lea Pagel Brown

Biological Sciences Theses & Dissertations

The levels of atmospheric CO₂ are rising and this affects the growth of plants and the ecosystems in which they reside. Plants take up additional C from the atmosphere and have potential to sequester C in the soil. I investigated the sequestration of C belowground and the microbial processes that control C retention in the soil. This study was conducted in a Florida scrub-oak ecosystem, where CO₂ levels have been elevated to twice ambient since 1996 in open top chambers. There were eight replicates of ambient CO₂ chambers and eight replicates of twice-ambient CO₂ levels. The …

Benthic Biological Monitoring Program Of The Elizabeth River Watershed (2004), Daniel M. Dauer

Elizabeth River Reports

Executive Summary

Macrobenthic communities of the Elizabeth River watershed have been quantitatively sampled since summer 1999. This report presents the data from the sixth year of sampling in 2004. The three objectives of the Benthic Biological Monitoring Program of the Elizabeth River watershed are: (1) To characterize the health of the tidal waters of the Elizabeth River watershed as indicated by the structure of the benthic communities. ( 2) To conduct trend analyses on long-term data at 14 fixed-point stations to relate temporal trends in the benthic communities to changes in water and/or sediment quality. Trend analyses will be updated …

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. …

Recruitment In Degraded Marine Habitats: A Spatially Explicit, Individual-Based Model For Spiny Lobster, Mark J. Butler Iv, Thomas W. Dolan Iii, John H. Hunt, Kenneth A. Rose, William F. Herrnkind

Biological Sciences Faculty Publications

Coastal habitats that serve as nursery grounds for numerous marine species are badly degraded, yet the traditional means of modeling populations of exploited marine species handle spatiotemporal changes in habitat characteristics and life history dynamics poorly, if at all. To explore how nursery habitat degradation impacts recruitment of a mobile, benthic species, we developed a spatially explicit, individual-based model that describes the recruitment of Caribbean spiny lobster (Panulirus argus) in the Florida Keys, where a cascade of environmental disturbances has reconfigured nursery habitat structure. In recent years, the region has experienced a series of linked perturbations, among them, seagrass die-offs, …

Side-By-Side Comparison Of Young Grab And Composite Petite Ponar Grab Samples For The Calculation Of The Benthic Index Of Biological Integrity(B-Ibi), Daniel M. Dauer, Michael F. Lane

Benthic Applications

(First paragraph) The Virginia Department of Environmental Quality (DEQ) intends to unite elements of its National Coastal Assessment Program (NCA) with its Chesapeake Bay Probabilistic Benthic Monitoring (CBP-PBM) Program beginning in the summer of 2005. The primary motivations for this decision were two-fold. First, the probable reduction of federal grant support for the NCA Program after the summer of 2004 would require considerable restructuring of the of DEQ’s estuarine probabilistic monitoring to continue with a comprehensive program in the future. Second, the current CBP-PBM Program has not provided sufficient data for the assessment of minor tidal tributary segments using the …

Feeding Behavior And Conditioning In Two Heterotrophic Dinoflagellates, Todd A. Egerton

Biological Sciences Theses & Dissertations

Growth and abundance of heterotrophic dinoflagellate predators are generally attributed to the availability of algal prey. Several species of dinoflagellates feed on a wide variety of food types including fish. However the actual feeding preferences of dinoflagellates have been much less studied. In the few studies that have been carried out on dinoflagellate feeding preference, none have looked at possible factors that may affect preference. I conducted three experiments on the toxic dinoflagellate Pfiesteria piscicida and the related unnamed species Cryptoperidiniopsis brodyi which, (1) calculated the feeding preferences between algal Rhodomonas prey and fish blood cells and identified factors that …

Morphological And Molecular Defects In Zebrafish Embryos (Danio Rerio) After Chromated Copper Arsenate Exposure, Kerry Jean Lee

Biological Sciences Theses & Dissertations

This investigation identified the morphological defects caused by different concentrations of chromium, copper, and arsenic (CCA) on the developing zebrafish embryo; in addition to defects caused by the three combined components (complete CCA). A change in the DNA of the developing embryos in response to the three components of CCA and complete CCA was also determined. Early Dania rerio embryos were cultured for five days with various concentrations of CCA components and complete CCA. Morphological defects were assessed with light microscopy and DNA fragmentation was determined by agarose gel electrophoresis. Embryonic exposure of D. rerio to sub lethal concentrations of …

Status And Trends In Water Quality And Living Resources In The Virginia Chesapeake Bay: James River (1985-2004), Daniel M. Dauer, Harold G. Marshall, John R. Donat, Michael F. Lane, Suzanne C. Doughten, Peter L. Morton, Frederick A. Hoffman

Status and Trends for Virginia Chesapeake Bay

A marked decline in the water quality of the Chesapeake Bay has occurred over the past several decades. The disappearance of submerged aquatic vegetation in certain regions of the Bay, declines in the abundance of some commercially and recreationally important species, increases in the incidence of low dissolved oxygen events, changes in the Bay's food web, and other ecological problems have been related to the deteriorating water quality. The results of concentrated research efforts in the late 1970s and early 1980s stimulated the establishment of Federal and state directives to better manage the Chesapeake Bay watershed. By way of the …

Status And Trends In Water Quality And Living Resources In The Virginia Chesapeake Bay: Rappahannock River (1985-2004), Daniel M. Dauer, Harold G. Marshall, John R. Donat, Michael F. Lane, Peter L. Morton, Suzanne C. Doughten, Frederick A. Hoffman

Status and Trends for Virginia Chesapeake Bay

A marked decline in the water quality of the Chesapeake Bay has occurred over the past several decades. The disappearance of submerged aquatic vegetation in certain regions of the Bay, declines in the abundance of some commercially and recreationally important species, increases in the incidence of low dissolved oxygen events, changes in the Bay's food web, and other ecological problems have been related to the deteriorating water quality. The results of concentrated research efforts in the late 1970s and early 1980s stimulated the establishment of Federal and state directives to better manage the Chesapeake Bay watershed. By way of the …

Status And Trends In Water Quality And Living Resources In The Virginia Chesapeake Bay: York River (1985-2004), Daniel M. Dauer, Harold G. Marshall, John R. Donat, Michael F. Lane, Suzanne C. Doughten, Frederick A. Hoffman

Status and Trends for Virginia Chesapeake Bay

A marked decline in the water quality of the Chesapeake Bay has occurred over the past several decades. The disappearance of submerged aquatic vegetation in certain regions of the Bay, declines in the abundance of some commercially and recreationally important species, increases in the incidence of low dissolved oxygen events, changes in the Bay's food web, and other ecological problems have been related to the deteriorating water quality. The results of concentrated research efforts in the late 1970s and early 1980s stimulated the establishment of Federal and state directives to better manage the Chesapeake Bay watershed. By way of the …

Effects Of Human Disturbances On The Behavior Of Wintering Ducks, Melissa L. Pease, Robert K. Rose, Mark J. Butler

Biological Sciences Faculty Publications

Human activity causes wintering waterfowl to expend energy to avoid humans at a time in their annual cycle when energy conservation is important to survival, migration, and breeding reserves. Understanding the effects of recreational activities on waterfowl is important to managing natural resource areas where migratory birds depend on wetland habitat for resting and feeding. We investigated responses of 7 species of dabbling ducks to 5 different experimental human activities, (a pedestrian, a bicyclist, a truck traveling at 2 different speeds, and an electric passenger tram). Responses of ducks depended on type of disturbance, species, and distance from disturbances. Most …

Status And Trends In Water Quality And Living Resources In The Virginia Chesapeake Bay: York River (1985-2003), Daniel M. Dauer

Status and Trends for Virginia Chesapeake Bay

The Virginia Chesapeake Bay and its tidal tributaries continue to show some environmental trends indicating progress toward restoration of a more balanced and healthy ecosystem. However, the Bay system remains degraded and some areas and indicators show continuing degradation. Progress in reducing nutrient inputs has made demonstrable improvements and we expect that continued progress toward nutrient reduction goals, along with appropriate fisheries management and chemical contaminant controls, will result in additional improvements to the Bay. Findings from the last 18 years of the monitoring programs are highlighted below. In 1995, the Virginia DEQ instituted changes to its analytical techniques for …

Status And Trends In Water Quality And Living Resources In The Virginia Chesapeake Bay: Rappahannock River (1985-2003), Daniel M. Dauer, Harold G. Marshall, John R. Donat, Michael F. Lane, Suzanne C. Doughten, Frederick A. Hoffman

Status and Trends for Virginia Chesapeake Bay

The Virginia Chesapeake Bay and its tidal tributaries continue to show some environmental trends indicating progress toward restoration of a more balanced and healthy ecosystem. However, the Bay system remains degraded and some areas and indicators show continuing degradation. Progress in reducing nutrient inputs has made demonstrable improvements and we expect that continued progress toward nutrient reduction goals, along with appropriate fisheries management and chemical contaminant controls, will result in additional improvements to the Bay. Findings from the last 18 years of the monitoring programs are highlighted below. In 1995, the Virginia DEQ instituted changes to its analytical techniques for …

Status And Trends In Water Quality And Living Resources In The Virginia Chesapeake Bay: James River (1985-2003), Daniel M. Dauer, Harold G. Marshall, John R. Donat, Michael F. Lane, Suzanne C. Doughten, Frederick A. Hoffman

Status and Trends for Virginia Chesapeake Bay

The Virginia Chesapeake Bay and its tidal tributaries continue to show some environmental trends indicating progress toward restoration of a more balanced and healthy ecosystem. However, the Bay system remains degraded and some areas and indicators show continuing degradation. Progress in reducing nutrient inputs has made demonstrable improvements and we expect that continued progress toward nutrient reduction goals, along with appropriate fisheries management and chemical contaminant controls, will result in additional improvements to the Bay. Findings from the last 18 years of the monitoring programs are highlighted below.

In 1995, the Virginia DEQ instituted changes to its analytical techniques for …

Circulation, Mixing And The Distribution Of Remineralized Nutrients, Larry P. Atkinson, John Huthnance, Jose L. Blanco

CCPO Publications

No abstract provided.