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Biological Sciences Theses & Dissertations

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Full-Text Articles in Ecology and Evolutionary Biology

Influence Of Abiotic Drivers And Plant Community Interactions On Bald Cypress (Taxodium Distichum) Seedlings: Implications For Restoration, Victoria Ellis Aug 2023

Influence Of Abiotic Drivers And Plant Community Interactions On Bald Cypress (Taxodium Distichum) Seedlings: Implications For Restoration, Victoria Ellis

Biological Sciences Theses & Dissertations

Forested freshwater wetlands are valuable ecosystems that provide habitat for numerous species, sequester carbon, and act as sinks for excess water and nutrients. Historically, these ecosystems have been heavily degraded by anthropogenic activities leading to loss of ecosystem services and a desire to restore freshwater forested wetland habitat. Thus, science-backed approaches for the restoration of freshwater forested wetlands are necessary to ensure restoration goals are met. This body of research employed the Stress Gradient Hypothesis to test whether a multi-species planting approach using Juncus effusus (L.) (soft rush) could facilitate the survival of Taxodium distichum (L.) Rich. (bald cypress) seedlings …

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Landscape Genetics Of The Gulf Coast Tick, Amblyomma Maculatum, Sara Simmons Benham May 2023

Landscape Genetics Of The Gulf Coast Tick, Amblyomma Maculatum, Sara Simmons Benham

Biological Sciences Theses & Dissertations

Connectivity among populations helps to maintain genetic diversity, population stability, and resilience. The Gulf Coast tick, Amblyomma maculatum, is a vector of the pathogen Rickettsia parkeri. Persistence of tick populations with high rates of R. parkeri infection poses health risks to humans and animals. Mitochondrial haplotypes were characterized by sequencing a fragment of the mitochondrial 16S rRNA gene. A comparative study of A. maculatum and Amblyomma americanum was conducted to identify similar and unique patterns between the species within the same region. Next, I compared A. maculatum sites across three different regions of the United States. This work …

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The Influences Of Disperser Behavior, Host Availability, And Environmental Conditions On The Distribution Of Oak Mistletoe [Phoradendron Leucarpum (Raf.) Reveal & M. C. Johnst.] In Eastern Virginia And North Carolina, Nicholas Pearce Flanders Aug 2022

The Influences Of Disperser Behavior, Host Availability, And Environmental Conditions On The Distribution Of Oak Mistletoe [Phoradendron Leucarpum (Raf.) Reveal & M. C. Johnst.] In Eastern Virginia And North Carolina, Nicholas Pearce Flanders

Biological Sciences Theses & Dissertations

Mistletoes are shrubs that typically parasitize the branches of host trees and rely on avian frugivores for seed dispersal. Because mistletoes are restricted to a narrow range of suitable recruitment sites and avian frugivores are more visible than other guilds of seed dispersers, mistletoe-frugivore systems afford opportunities for assessing the roles of dispersal limitation and local environment in determining plant distribution. These mechanisms have been proposed as determinants of the observed association of oak mistletoe [Phoradendron leucarpum (Raf.) Reveal & M. C. Johnst.] with forested wetlands in eastern Virginia and North Carolina, USA. I tested the alternative hypothesis that …

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Nestedness And Modularity Of Avian Metacommunities Across Gradients Of Chesapeake Bay Island Characteristics, Grant Walter Bowers Aug 2022

Nestedness And Modularity Of Avian Metacommunities Across Gradients Of Chesapeake Bay Island Characteristics, Grant Walter Bowers

Biological Sciences Theses & Dissertations

Islands are not only great models for understanding the ways in which communities are linked by the dispersal of their members to form metacommunities, but are of particular interest to conservationists. One important aspect of metacommunity structure is the degree of nestedness—whether or not less speciose communities are perfect subsets of more speciose communities. Another important metric of metacommunity structure is modularity—the degree to which communities belong to modules composed of other communities that share the same species but have little species overlap with communities from different modules. Environmental gradients have received insufficient attention as predictors of metacommunity nestedness and …

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Temporal Dynamics And Seed Dispersal In Plant-Frugivore Communities Of The Dominican Republic, Spencer Christian Schubert May 2022

Temporal Dynamics And Seed Dispersal In Plant-Frugivore Communities Of The Dominican Republic, Spencer Christian Schubert

Biological Sciences Theses & Dissertations

Plant-animal mutualisms are a foundational component of biodiversity in terrestrial ecosystems. Most tropical forest plants have adapted to produce fleshy fruits to attract frugivorous animals to disperse seeds. Interaction patterns among plant taxa and their seed dispersers are driven by a complex suite of factors involving their evolutionary history and environmental context, and the structure of these mutualistic networks are theoretically tied to their ecological function. I carried out a series of field studies to investigate the temporal dynamics of mutualistic interactions of plant and avian frugivore communities in the central Dominican Republic and how their characteristics affect seed dispersal …

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Efficacy Of Sediment Contaminant Remediation Of The Benthos In A Segment Of The Southern Branch Of The Elizabeth River, Colton Martin Dec 2021

Efficacy Of Sediment Contaminant Remediation Of The Benthos In A Segment Of The Southern Branch Of The Elizabeth River, Colton Martin

Biological Sciences Theses & Dissertations

The bottom sediment of the Southern Branch of the Elizabeth River, a tributary of Chesapeake Bay, was historically contaminated with hydrocarbons from industrial sources especially wood treatment facilities. The Elizabeth River Project selected a section of the bottom off Money Point in the Southern Branch for a sediment contaminant remediation effort. Prior to initiation of remediation efforts, a survey occurred in summer 2010 to characterize the ecological condition of the benthic communities off Money Point compared to benthic communities of a benthic region across the channel and northwest of Money Point near Blows Creek. That study characterized the benthos of …

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Population Dynamics And Dispersal Coalitions In The Cooperatively Breeding Acorn Woodpecker, Natasha Hagemeyer Apr 2021

Population Dynamics And Dispersal Coalitions In The Cooperatively Breeding Acorn Woodpecker, Natasha Hagemeyer

Biological Sciences Theses & Dissertations

Dispersal is a critical life-stage with consequences not only for the individual, but for population dynamics and thus the fate of the whole species. The creation of dispersal coalitions can lead to complex outcomes and affect how changes in abundance occur on the landscape. I examined population dynamics and dispersal coalitions in a population of cooperatively breeding acorn woodpeckers in central California, USA. Using a 34-year dataset on occupancy and abundance, I determined that increases in abundance were determined by dispersal to new locations. This resulted in increased occupancy, rather than increases in group size and larger coalitions. I then …

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The Role Of Backreef Soundscapes And Their Spatial Structure For Recruitment Of Tropical Marine Larvae, Emily R. Anderson Apr 2021

The Role Of Backreef Soundscapes And Their Spatial Structure For Recruitment Of Tropical Marine Larvae, Emily R. Anderson

Biological Sciences Theses & Dissertations

Underwater sound is a cue used by many marine larvae to orient to coastal habitats including backreef, sponge-dominated hardbottom habitat in the Florida Keys (Florida, USA) – a particularly “noisy” coastal habitat. However, the distance over which acoustic cues are attractive to settlement-stage larvae - is generally unknown. I examined this phenomenon in a region of the Florida Keys where mass sponge die-offs have diminished both underwater soundscapes and larval settlement. The absence of pronounced hardbottom-associated sound over such a large area allowed me to experimentally test in situ the response of fish and invertebrate larvae to broadcasted sounds at …

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A Test Of Rad Capture Sequencing On Ethanol-Preserved Centennial And Contemporary Specimens Of Philippine Fishes, Madeleine I. Kenton Apr 2021

A Test Of Rad Capture Sequencing On Ethanol-Preserved Centennial And Contemporary Specimens Of Philippine Fishes, Madeleine I. Kenton

Biological Sciences Theses & Dissertations

Understanding the relationship between ecological characteristics and genetic change in natural populations in different time scales can reveal how anthropogenic stressors affect natural populations and can improve the success of conservation strategies. The purpose of the Philippines Partnerships for International Research and Education (PIRE) project is to examine levels of genetic change between historical fish samples collected by the USS Albatross expedition in the early 1900s in the Philippines and contemporary populations collected at the same localities. This study tests genetic protocols to process historical and contemporary DNA for simultaneous comparison. Two DNA library preparation methods, single digest RADseq (“un-baited” …

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Not Too Hot, Not Too Cold, But Moderately Variable: The Influence Of Environmental Variability On Coral Thermal Tolerance, Courtney Nicole Klepac Dec 2020

Not Too Hot, Not Too Cold, But Moderately Variable: The Influence Of Environmental Variability On Coral Thermal Tolerance, Courtney Nicole Klepac

Biological Sciences Theses & Dissertations

Anthropogenic climate change is causing an increase in the frequency and severity of marine heat waves, resulting in declining health of coral reef ecosystems worldwide. Coral bleaching events – the breakdown in symbiosis between the coral host and their intracellular photosynthetic algae – are increasingly common in recent years and contribute to widespread losses in coral cover. However, bleaching and heat stress responses vary across spatial scales both within and among coral species. Coral populations native to highly variable environments can have greater bleaching resistance than corals from more stable habitats and corals transplanted into these variable reef sites can …

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Assessment Of Factors Influencing Migratory Landbird Use Of Forested Stopover Sites Along The Delmarva Peninsula During Autumn Migration, J. Andrew Arnold Dec 2020

Assessment Of Factors Influencing Migratory Landbird Use Of Forested Stopover Sites Along The Delmarva Peninsula During Autumn Migration, J. Andrew Arnold

Biological Sciences Theses & Dissertations

Autumn migration is a time when billions of birds move from breeding grounds in North America to wintering grounds in Central and South America, with many individuals relying on stopover habitats en route for resting and refueling purposes. These stopover sites are critical to the survival of the hundreds of species of migratory landbirds that migrate annually, and thus identifying important stopover sites is a high priority for conserving such taxa. The Delmarva Peninsula; a coastal region of Delaware, Maryland, and Virginia along the mid-Atlantic flyway; consists of forested habitats with ample food and shelter that likely serves as quality …

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Diet Analysis Of Stranded Bottlenose Dolphins (Tursiops Truncatus) In Virginia, Kristen Marie Volker Apr 2020

Diet Analysis Of Stranded Bottlenose Dolphins (Tursiops Truncatus) In Virginia, Kristen Marie Volker

Biological Sciences Theses & Dissertations

This study describes the diet of bottlenose dolphins (Tursiops truncatus) stranded in Virginia via stomach content analysis and considers factors such as proportion of numerical abundance and reconstructed mass, frequency of occurrence, average reconstructed prey size, prey diversity and quantity, and otolith degradation code. Fish size was estimated via regression equations established from local fish collected during the study that derive wet weight directly from otolith length or width. Squid size is estimated from previously published equations. Soniferous fishes dominated the diet, especially Atlantic croaker, spot, and seatrout spp., adding evidence to the theory that bottlenose dolphins passively …

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The Effects Of Hackberry Psyllids On Refueling Migratory Songbirds And Autumnal Seed Rain, Chance H. Hines Apr 2020

The Effects Of Hackberry Psyllids On Refueling Migratory Songbirds And Autumnal Seed Rain, Chance H. Hines

Biological Sciences Theses & Dissertations

Hackberry psyllids (Pachypsylla sp) are a galling insect native to North America’s hackberry trees (Celtis sp). Hackberry leaf-galling psyllids are ephemerally abundant during autumn, a period of time when migratory songbirds are traveling from their breeding areas in temperate North America south to their winter ranges. These migrations are energetically taxing and many songbirds fuel their journey with resources like insects and fruits. I captured birds with mist nets, observed foraging behaviors, and captured avian-dispersed fleshy fruit seeds (hereafter, seed rain) rain during the autumn of 2016 and 2017 to determine how hackberry psyllids, an ephemerally …

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Tick Control Methods For Amblyomma Americanum In Virginia: Applications And Modeling, Alexis Lynn White Oct 2019

Tick Control Methods For Amblyomma Americanum In Virginia: Applications And Modeling, Alexis Lynn White

Biological Sciences Theses & Dissertations

Tick-borne diseases continue to increase in the United States, and yet no comprehensive method of tick control currently exists. The lone star tick, Amblyomma americanum, is an aggressive human-biting tick and vector of several pathogens which effect both humans and other animals. Standard control methods do not work as well for A. americanum as they do for the more commonly studied blacklegged tick, Ixodes scapularis. TickBot, a tick-killing robot, is a potential method to control A. americanum that lures ticks to its path with carbon dioxide and the ticks die from contact with a permethrin-treated cloth that is …

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Global Conservation Status And Threat Patterns Of The World’S Most Prominent Forage Fishes (Teleostei, Clupeiformes), Tiffany L. Birge Oct 2019

Global Conservation Status And Threat Patterns Of The World’S Most Prominent Forage Fishes (Teleostei, Clupeiformes), Tiffany L. Birge

Biological Sciences Theses & Dissertations

Conserving biodiversity is one of the greatest ethical responsibilities and challenges humans face. Understanding the conservation status of taxonomic groups provides a systematic way to prioritize efforts to combat biodiversity loss. The 405 species within the order Clupeiformes are the herrings, shads, sardines, anchovies, menhadens and relatives that include many of the most important marine forage fishes. These small, schooling fishes are economically, ecologically and culturally significant globally. Despite their contribution to global fisheries and our increasing reliance on these fishes for food and industrial commodities, they are generally poorly known with limited information regarding basic biology and population trends. …

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In Hot Water: Thermal Acclimation Is Insufficient To Save Corals In The Anthropocene, Harmony Alise Martell Jul 2019

In Hot Water: Thermal Acclimation Is Insufficient To Save Corals In The Anthropocene, Harmony Alise Martell

Biological Sciences Theses & Dissertations

Scleractinian corals are animal partners in exquisite symbioses with a suite of algal, microbial, fungal and viral associates comprising miniature ecosystems collectively referred to as a holobiont. In recent decades, ocean warming has jeopardized the delicate balance of the very symbioses that have enabled coral survival. Thermal stress causes a reduction of algal symbionts, a phenomenon referred to as ‘coral bleaching’ that represents dysbiosis in the holobiont and often leads to mortality. Current thermal acclimation theory states variation and gradual increases in temperature can ameliorate thermal stress. Indeed, there is evidence some coral species have some capacity to acclimatize to …

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Cryptic Herbivorous Invertebrates Restructure The Composition Of Degraded Coral Reef Communities In The Florida Keys, Florida, Usa, Angelo Jason Spadaro Apr 2019

Cryptic Herbivorous Invertebrates Restructure The Composition Of Degraded Coral Reef Communities In The Florida Keys, Florida, Usa, Angelo Jason Spadaro

Biological Sciences Theses & Dissertations

Coral reefs have been on a trajectory of decline for nearly a century due to a variety of factors that have contributed to the shift in these communities away from dominance by reef-building corals, with commensurate changes on community composition and function. Florida’s reefs are a compelling example of a degraded system that has undergone a phase shift, and thus offered an excellent model system for my study of the effects of grazing by cryptic herbivores on community composition and their potential restoration value. I had four major objectives: (1) determine the suitability of Maguimithrax spinosissimus for manipulating grazing intensity …

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Sponge Community Biocomplexity, Competition, And Functional Significance In Hard-Bottom Habitats Of The Florida Keys, Fl (Usa), Marla Maxine Valentine Apr 2019

Sponge Community Biocomplexity, Competition, And Functional Significance In Hard-Bottom Habitats Of The Florida Keys, Fl (Usa), Marla Maxine Valentine

Biological Sciences Theses & Dissertations

Sponges can have powerful effects on ecosystem processes in shallow, tropical marine ecosystems and are an integral component of the bentho-pelagic cycle of nutrients, via filtering of dissolved and particulate organic matter from the water column. The diversity of marine communities is thought to play a determining role in intensity of ecosystem processes; thus the loss of taxa alters community function and by extension ecosystem processes. Coastal sponge populations worldwide are increasingly exposed to declining water quality that in several regions has resulted in mass sponge mortalities and reduced sponge diversity. In the Florida Keys (Florida, USA), for example, frequent …

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Local Adaptation Signatures In Thermal Performance Of The Temperate Coral Astrangia Poculata, Hannah Elise Aichelman Jul 2018

Local Adaptation Signatures In Thermal Performance Of The Temperate Coral Astrangia Poculata, Hannah Elise Aichelman

Biological Sciences Theses & Dissertations

The Northern Star Coral (Astrangia poculata) is an understudied temperate scleractinian coral that provides unique opportunities to understand the roles of phenotypic plasticity and local adaptation in coral physiological tolerance limits. Astrangia poculata inhabits hard bottom ecosystems from the northwestern Atlantic to the Gulf of Mexico and withstands an annual temperature range up to 20°C. Additionally, A. poculata is facultatively symbiotic and co-occurs in both symbiotic (“brown”) and aposymbiotic (“white”) states. Here, brown and white A. poculata were collected from Virginia (VA) and Rhode Island (RI), USA and exposed to heat (18-32°C) and cold (18-6°C) temperature assays during …

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Potential Interaction Analysis Of Offshore Wind Energy Areas And Breeding Avian Species On The Us Mid-Atlantic Coast, Jeri Lynn Wisman Jul 2018

Potential Interaction Analysis Of Offshore Wind Energy Areas And Breeding Avian Species On The Us Mid-Atlantic Coast, Jeri Lynn Wisman

Biological Sciences Theses & Dissertations

Due to increasing US interest in developing wind energy sites in offshore waters, we synthesized existing data on colonial breeding seabird populations with the potential risk of interacting with lease areas in the mid-Atlantic. Previous efforts by BOEM and NOAA have predicted avian density using at-sea survey data; we seek to complement this work by focusing specifically on birds during the critical and energetically demanding breeding life history stage. We combined colony size and location for each species along the mid-Atlantic coast with buffers around the colonies that correlate with the species’ foraging range. We integrated population size, vulnerability to …

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The Importance Of Keeping The Big Ones: Harvest Slot Limits And Marine Protected Areas For The Management Of The Caribbean Spiny Lobster, Gayathiri Gnanalingam Jul 2018

The Importance Of Keeping The Big Ones: Harvest Slot Limits And Marine Protected Areas For The Management Of The Caribbean Spiny Lobster, Gayathiri Gnanalingam

Biological Sciences Theses & Dissertations

Fishing typically removes the oldest and/or largest individuals from populations undermining stability and reproductive success. Traditional fisheries management tools fail to protect these oldest and/or largest individuals, but two less conventional tools: marine protected areas (MPAs), and harvest slot limits have the potential to do so. Here I tested the possible use of these tools for the Caribbean spiny lobster, Panulirus argus, an iconic and economically valued species. After decades of intense fishing, the largest lobsters have largely been wiped out. The loss of the largest lobsters is significant as large lobsters have considerably greater reproductive potential than their …

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Fishery Interaction Modeling Of Cetacean Bycatch In The California Drift Gillnet Fishery To Inform A Dynamic Ocean Management Tool, Nicholas B. Sisson Apr 2018

Fishery Interaction Modeling Of Cetacean Bycatch In The California Drift Gillnet Fishery To Inform A Dynamic Ocean Management Tool, Nicholas B. Sisson

Biological Sciences Theses & Dissertations

Understanding the drivers that lead to interaction between target species in a fishery and marine mammals is a critical aspect in efforts to reduce bycatch. In the California drift gillnet fishery static management approaches and gear changes have reduced bycatch but neither measure ascertains the underlying dynamics causing bycatch events. To avoid further potentially drastic measures such as hard caps, dynamic management approaches that consider the scales relevant to physical dynamics, animal movement and human use could be implemented. A key component to this approach is determining the factors that lead to fisheries interactions. Using 25 years (1990-2014) of National …

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Marine Reserves Promote Coral Reef Resilience By Mitigating Human Impacts Through The Restoration Of Parrotfish Populations, Increasing Their Reproductive Output And Seeding Neighboring Overfished Reefs, Brian L. Stockwell Oct 2017

Marine Reserves Promote Coral Reef Resilience By Mitigating Human Impacts Through The Restoration Of Parrotfish Populations, Increasing Their Reproductive Output And Seeding Neighboring Overfished Reefs, Brian L. Stockwell

Biological Sciences Theses & Dissertations

Coral reefs are some of the most productive ecosystems on the planet, providing fisheries resources for over a billion people with billions of dollars in revenue from tourism for developing nations. Coral reefs are under threat from overfishing and water pollution, resulting in less productive algae dominated reefs. Marine reserves are widely expected to promote the resilience of reefs by protecting and increasing the abundance of herbivorous fishes that can graze on algae, therefore directly or indirectly preventing coral to algal phase shifts. However, the ability of marine reserves to mitigate human impacts, restore herbivorous fish populations and seed nearby …

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Population Structure Of Lethrinus Lentjan (Lethrinidae, Percoidei) Across The South China Sea And The Philippines Is Detected With Lane-Affected Radseq Data, Ellen E. Biesack Oct 2017

Population Structure Of Lethrinus Lentjan (Lethrinidae, Percoidei) Across The South China Sea And The Philippines Is Detected With Lane-Affected Radseq Data, Ellen E. Biesack

Biological Sciences Theses & Dissertations

Southeast Asia includes the Coral Triangle, a marine biodiversity hotspot that supports important fishery resources experiencing varied threats. Patterns of speciation and population structure in the Coral Triangle have been examined to test hypotheses relating to the historical geologic processes that may have influenced this biodiversity phenomenon. This study investigates the genetic population structure of the Pink-ear Emperor Snapper, Lethrinus lentjan (Lacepède, 1802), across the Philippines and the South China Sea. The species is fished throughout the Coral Triangle by subsistence and commercial fishers and their landings have been in decline for several years, which could be indicative of depleted …

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Tracing The Genetic Footprints Of The Redbelly Yellowtail Fusilier, Caesio Cuning, Across Multiple Spatial And Evolutionary Scales, Amanda Susanne Ackiss Oct 2017

Tracing The Genetic Footprints Of The Redbelly Yellowtail Fusilier, Caesio Cuning, Across Multiple Spatial And Evolutionary Scales, Amanda Susanne Ackiss

Biological Sciences Theses & Dissertations

Overfishing is one of the most pervasive threats to coral reef ecosystems, and management of these multi-species resources is hampered by limited species-specific population level information. The reefs in the western tropical Pacific Ocean, including the Coral Triangle, are the most bio-diverse in the world. Home to more than 400 million people, this region contains some of the most threatened coral reef ecosystems. Presented here is the first comprehensive analysis of the genetic structure of Caesio cuning, planktivorous fish inhabiting reefs in the Coral Triangle and western Pacific Ocean. Data from both classical Sanger and next-generation sequencing were analyzed …

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The Effect Of "Casitas" On Lobster Biology And Fishery Sustainability In The Bahamas, Lester George Gittens Jul 2017

The Effect Of "Casitas" On Lobster Biology And Fishery Sustainability In The Bahamas, Lester George Gittens

Biological Sciences Theses & Dissertations

“Casitas” (artificial table-like structures) are a commercial fishing gear used to harvest Caribbean spiny lobster (Panulirus argus) in the Caribbean and in The Bahamas, where lobster is the most valuable fishery. Yet, casitas are largely unregulated in The Bahamas and they may threaten fishery sustainability through alteration of lobster growth, disease, or mortality rates and due to insufficient information concerning their number and location. Focusing on the lobster fishery in The Bahamas, my objectives were to: (1) investigate the mortality, growth, and susceptibility to disease of lobsters collected in casitas compared to wooden traps and those living in …

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Determining Critical Internesting And Foraging Habitats For The Conservation Of Sea Turtles In Gabon, Africa Using Satellite Tracking And Stable Isotope Analysis, Tiffany M. Dawson Jul 2017

Determining Critical Internesting And Foraging Habitats For The Conservation Of Sea Turtles In Gabon, Africa Using Satellite Tracking And Stable Isotope Analysis, Tiffany M. Dawson

Biological Sciences Theses & Dissertations

Understanding the horizontal and vertical habitat of olive ridley sea turtles (Lepidochelys olivacea), a threatened species, is critical for determining regions of protection that may effectively reduce bycatch, the largest threat to this species. Satellite transmitters were used to determine the movement and dive behavior of 21 female olive ridley turtles tagged in Pongara National Park, Gabon during the 2012, 2013, and 2015 nesting seasons. A switching state space model was used to filter the tracking data and categorize the internesting and post-nesting movements. Gridded utilization distribution (UD) home range analysis of tracking data revealed that the entire core habitat …

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Strawberries (Frag X Anan) Are Bigger When Native Mason Bees (Osmia Lignaria) Are Experimentally Added To Small Farms, Laura A. Campbell Apr 2017

Strawberries (Frag X Anan) Are Bigger When Native Mason Bees (Osmia Lignaria) Are Experimentally Added To Small Farms, Laura A. Campbell

Biological Sciences Theses & Dissertations

Agriculture is the cornerstone of our economy, and pollination plays a vital role in nearly all non-wind pollinated crops. Declining honey bee populations have caused a more diligent investigation into using solitary bees for crop pollination. The native, solitary Orchard Mason Bee has shown to successfully pollinate almonds and apples, but there has been little work conducted on their effectiveness as a low fruit crop pollinator. This study assesses their effectiveness as a small strawberry farm pollinator, and preferences for nesting materials. Mason bee cocoons and nest homes made with different materials (bamboo, Phragmites, or wood) were supplemented on …

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Coarse Root Biomass And Architecture: Applications Of Ground Penetrating Radar, John Claude Bain Oct 2016

Coarse Root Biomass And Architecture: Applications Of Ground Penetrating Radar, John Claude Bain

Biological Sciences Theses & Dissertations

The effectiveness of ground penetrating radar (GPR) to identify and quantify coarse roots was tested in a mixed-oak forest in Southeastern Virginia using experimental pits and locally excavated root segments. GPR was found to be highly dependent on low soil moisture levels as it is unable to differentiate root structures if they possess similar moisture content as their surrounding soil. Likewise, GPR was unable to identify simulated dead roots. This does not alter the effectiveness of GPR to measure living coarse root biomass, but does present the potential for underestimation of carbon storage in coarse root structures, as a dead …

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A Hitchhiker’S Guide To Invasion Biology: Describing The Ecological Mechanisms Underlying The Range Expansions Of Two Ixodid Tick Species, Robyn M. Nadolny Apr 2016

A Hitchhiker’S Guide To Invasion Biology: Describing The Ecological Mechanisms Underlying The Range Expansions Of Two Ixodid Tick Species, Robyn M. Nadolny

Biological Sciences Theses & Dissertations

Increasing incidence of many tick-borne diseases have been linked to recent expansions of tick species distributions. Many tick species are expanding their ranges because of anthropogenic changes in the landscape, shifting climatic variables, and increasing populations of suitable host species and tick habitat. Few empirical studies have been performed, however, investigating the ecological mechanisms underlying these range expansions. Ticks are parasitic organisms that disperse across landscape by hitchhiking on hosts, but must then survive in the environment for long periods of time between bloodmeals. Two species of ixodid tick, Ixodes affinis and Amblyomma maculatum, are simultaneously expanding their ranges throughout …

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