Terrestrial and Aquatic Ecology Commons^™

Hydrodynamic Limitations To Mangrove Seedling Retention In Subtropical Estuaries, Kelly M. Kibler, Christian Pilato, Linda Walters, Melinda Donnelly, Jyotismita Taye

Flow-biota Interaction and Natural Infrastructure Design

Mangrove forest sustainability hinges upon propagule recruitment and seedling retention. This study evaluates biophysical limitations to mangrove seedling persistence by measuring anchoring force of two mangrove species (Rhizophora mangle and Avicennia germinans). Anchoring force was measured in 362 seedlings via lateral pull-tests administered in mangrove forests of two subtropical estuaries and in laboratory-based experiments. Removal mechanism varied with seedling age: newly-established seedlings failed due to root pull-out while seedlings older than 3 months failed by root breakage. Anchoring force of R. mangle seedlings was consistently and significantly greater than A. germinans (GLM: p = 0.002), however force to …

The Spatial Ecology And Habitat Selection Of A Spotted Turtle (Clemmys Guttata) Population In Southwest Michigan, Michela Coury

Masters Theses

Turtles are arguably the most threatened group of vertebrates on the planet. Anthropogenic influences such as habitat loss and fragmentation, road mortality, subsidized predators, climate change, and illegal collection have contributed to their global decline. Understanding which isolated populations of turtles are viable despite these synergistic threats is crucial for making conservation and management decisions. In Michigan, the spotted turtle (Clemmys guttata) is a threatened species subjected to many negative anthropogenic influences that accelerate its rapid population decline. In order to properly sustain their populations, the goal of my research was to investigate relevant factors that help us …

Loggerhead Shrike Detectability And Occurrence In Coastal South Carolina Urban Areas, Michelle Krauser

Electronic Theses and Dissertations

Grassland birds, such as the loggerhead shrike (Lanius ludovicianus), are threatened by extensive land-use change, including urbanization. Loggerhead shrikes have been declining since the early 1900s and are rare or extirpated in portions of their former range. Obtaining reliable population estimates of loggerhead shrikes is important to identify demographic trends and ensure conservation decisions are based on an accurate assessment of their current status. Imperfect detection, or the inability to detect every shrike during a survey, can result in biased population estimates. Estimating detection probability is labor-intensive and requires assumptions that are difficult to satisfy in most field studies. Understanding …

Enzootic Trends Of Crassostrea Virginica And Perkinsus Marinus In North Inlet Estuary, South Carolina, Nico Martin D'Amico

Electronic Theses and Dissertations

The Eastern oyster (Crassostrea virginica) co-occurs with the protozoan parasite Perkinsus marinus (the causative agent for "Dermo") in US Atlantic and Gulf of Mexico estuaries. Oyster host functions as an ecological engineer and agent for benthic-pelagic coupling are compromised when P. marinus infections are common in populations (prevalence) and high in individuals (intensity). P. marinus infections in oysters from North Inlet estuary, South Carolina were quantified in relation to shell height (60-76 mm, ≥76 mm), sex (functional female, male, indeterminate), water temperature, and salinity. Three fringing reefs on a longitudinal transect from the inlet mouth into the watershed were sampled …

A Review Of Current Methods In Avian Dietary Analysis And Their Integrated Application To Characterize The Trophic Niche Of Louisiana Waterthrush (Parkesia Motacilla)., Brandon Hoenig

Electronic Theses and Dissertations

Characterizing a species’ dietary composition presents an avenue to understand many facets of its ecological niche and can provide essential information for the species’ long-term conservation. To date, the vast majority of diet studies have relied on direct identification of prey during foraging observations or from diet samples to characterize the dietary habits of birds. However, advancements in laboratory-based approaches have revolutionized the field of trophic ecology by allowing researchers to indirectly infer dietary habits with higher resolution across greater time scales. Here, I apply two of these laboratory-based techniques, namely DNA metabarcoding and stable isotope analysis, to characterize the …

Investigation Of Dna Variability And Phylogenetic Relationships Of Perlesta (Plecoptera: Perlidae) In Mississippi, James C. Valentine, Mac H. Alford

Master's Theses

The genus Perlesta Banks, 1906 (Plecoptera: Perlidae) consists of 35 species, 33 native to the United States and Canada and two native to China. For over a century these small, brown stonefly adults and freckled yellow nymphs have gone by the name of the type species of the genus, Perlesta placida, but taxonomic work in the genus since 1989 has resulted in the recognition of additional species. These species were mostly recognized and described using morphological characteristics, but two areas that are lacking include (1) linking nymphs to adults and (2) phylogenetic analysis of all species occurring in Mississippi …

Identifying Key Stream Restoration Variables In An Agriculturally Impaired Chesapeake Bay Watershed, Julia Portmann

Masters Theses, 2020-current

The Chesapeake Bay watershed spans several states, supports diverse ecosystems, and is crucial to local economies. However, agricultural practices in this region impair water quality. The Smith Creek watershed, within the Shenandoah Valley, was designated a showcase watershed in 2010 by the United States Department of Agriculture to demonstrate the efficacy of implementing restoration projects. We sampled fifteen farms ranging from unrestored to thirty-six years since restoration. At each site, we conducted a kick-net survey for macroinvertebrates, measured canopy cover, algal density, substrate size, and bank height and angle. We identified macroinvertebrates to family and calculated the Chesapeake Basin-wide Index …

Seasonal Variation And Tracking Of Climate Niche Of A Migratory Bird, Javier Gutiérrez Illán, Guiming Wang, D. Tommy King, Fred L. Cunningham

United States Department of Agriculture Wildlife Services: Staff Publications

Migratory birds inhabit different areas during breeding and non-breeding seasons. Depending on the time of the year, they may utilize different resources available in seasonal habitats, but also are subjected to changing climate regimes during their annual life cycle. Migratory birds may adopt ecological niche tracking to cope with different environmental conditions between breeding and non-breeding grounds. The American White Pelican (Pelecanus erythrorhynchos, hereafter ‘AWPE’) is a short-distance migrant between the Gulf of Mexico coastal regions (nonbreeding grounds) and the Northern Great Plains (breeding grounds) of Canada and the US. The American White Pelican is a piscivore, feeding …

Detection And Occurrence Of Nerodia Harteri (Serpentes: Colubridae) In An Upper Portion Of The Brazos River Watershed, Jessica Yates

Electronic Theses and Dissertations

Semiaquatic snakes are disproportionately impacted by habitat alteration adjacent to wetlands because of their reliance on both terrestrial and aquatic habitats. Brazos River Watersnakes, Nerodia harteri, are endemic natricines with one of the most restricted geographic ranges in North America. I quantified detection and site occupancy probabilities of N. harteri and its sympatric congeners (N. erythrogaster and N. rhombifer), as well as microhabitat selection within the Nerodia community. Within occupied transects, search effort was positively correlated with detecting N. harteri, whereas environmental and/or habitat variables were better predictors for detecting the sympatric congeners. Microhabitat selection between …

Trophish: Building A Global Database Of Freshwater Trophic Interactions, Jacob M. Ridgway

Honors Thesis

Freshwater management and research frequently use the trophic data of freshwater fishes. Despite this fact, it is difficult to perform a simple search of dietary information for any one fish species. FishBase represents, to our knowledge, the largest compilation of freshwater dietary information to date. However, it excludes a large portion of the ecological literature due to its development taking place prior to the creation of most modern scientific search engines. Our project (TroPhish) is building upon FishBase by digitizing approximately 130 years of data from the fish predation literature. Data from the primary and grey (e.g. theses, dissertations, reports) …

A Genetic Evaluation Of The Impacts Of Dams On Sauger Movement Patterns In The Arkansas River, Emily R. Jonagan

ATU Theses and Dissertations 2021 - Present

Decreased habitat connectivity as a result of damming can lead to genetic isolation in fish communities, especially in highly migratory species. Sauger Sander canadensis is a migratory freshwater species native to the Arkansas River. Sauger are highly sought after by anglers during their annual spawning migration in late winter. In order to investigate the impacts Arkansas River dams on Sauger populations, fin clips were collected in the winters of 2019, 2020, and 2021 below eight dams in the McClellan-Kerr Arkansas River Navigational System (MKARNS). Fin clips were also collected from two reservoirs in Kansas to serve as distinct reference populations. …

An Analysis Of The Effects Of Temperature And Other Environmental Factors On Microorganismal Productivity Within Aquatic Ecosystems Using Long-Term Data From Various Lter And Ilter Sites, Andrew Dorbu

Theses and Dissertations

Global climate change is a phenomenon resulting in more extreme weather patterns and species diversity loss. In this study, I explore the impacts of climate change on regional patterns of microbial productivity. Variation in microbial productivity was explained using temperature, salinity, and dissolved oxygen as predictors in regression models with data from the LTER and iLTER network of sites that ranged from the poles to the equator. I found a positive relationship between temperature and productivity. Antarctica and Arctic sites exhibited the strongest positive relationships supporting prior research demonstrating temperature as one of the driving forces of productivity change in …

Effects Of Water Quality On Oyster Health On Georgia Coast, Laurel Henderson

Honors College Theses

ABSTRACT

Oysters are an economically and ecologically important shellfish species found along most coastlines. Along the Georgia coastline, oysters form extensive reefs, and are economically important as a food source. In addition, oysters perform a vital role in maintaining water quality due to their high filtration capacity in coastal waters. Oyster reefs form solid, 3-D substrate that prevent coastline erosion and provide structure for numerous other coastal species to grow, including many commercially and recreationally important species. Water quality factors, such as temperature and salinity, can influence oyster density, condition, and growth, and ultimately affect the services the reefs provide …

The Potential Role Of Phenotypic Plasticity In The Ability Of Hydrocotyle Bonariensis To Occupy Two Different Habitats, Harold Ralph Parsons Iii

Honors College Theses

Phenotypic plasticity is the ability of an organism to change morphology and/or physiology in response to changes in the environment. Hydrocotyle bonariensis is a coastal perennial herb found in both coastal sand dunes and inland coastal plain habitats in Georgia. The purpose of this study was to determine if there were differences in leaf morphology for populations of H. bonariensis in coastal sand dune and inland coastal plain habitats. Leaf morphology and microenvironmental variables were compared between H. bonariensis populations at Tybee Island (TI), GA, representing the coastal sand dune habitat, and Georgia Southern University Armstrong Campus (GSU) in Savannah, …

Severe Hypoxia Up-Regulates Gluconeogenesis In Daphnia, Morad C. Malek

Undergraduate Honors Theses

Hypoxia is a significant low oxygen state that has complex and diverse impacts on organisms. In aerobes, various adaptive responses to hypoxia are observed that vary depending on the level of oxygen depletion and previous adaptation, hence the continued attention to hypoxia as an important abiotic stressor. Adaptive responses to hypoxia are primarily governed by the hypoxia-inducible factors (HIFs), which activate downstream genetic pathways responsible for oxygen transport and metabolic plasticity. In aquatic habitats, oxygen availability can vary greatly over time and space. Therefore, aquatic organisms’ adaptation to hypoxia is likely pervasive, especially in genotypes originating from waterbodies prone to …

Effect Of Larval Experience On Learning Mate Preference In Bicyclus Anynana, Taryn Tibbs

Biological Sciences Undergraduate Honors Theses

Phenotypic traits are shaped by the interaction of an organism's genes and the environment they experience. The plasticity of phenotypic traits is particularly responsive to developmental environments which can shape adult traits, such as expressed behaviors like mate choice and the ability to learn preferences. The Lepidoptera species Bicyclus anynana has been shown to learn mate preference based on social interaction following emergence from the chrysalis, however if and how the social complexity of the larval experience affects this ability to learn is less understood. Here I test the effects of isolation during the larval period on a female’s ability …

How Flow Regime Affects Predator-Prey Relationships Of Stream Darter And Shiner Species, Anna E. Richardson

Biological Sciences Undergraduate Honors Theses

Analysis of the interactions between abiotic and biotic factors of environments and ecosystems is a highly valued area of research. This study focuses on the interactions between the biotic component of predation and foraging of certain stream fish species and the abiotic component of the flow regime that those species reside in. Gut content analysis followed by statistical calculations in the form of t-tests and chi -quared tests were performed on two fish species who both inhabited a stream with a groundwater flashy flow regime as well as a stream with a runoff flashy flow regime. The research showed that …

Checking The Checkered Taxonomy Of Plötz's Checkered Skippers (Hesperiidae: Pyrgini), Jing Zhang, Qing Cong, John M. Burns, Nick V. Grishin

The Taxonomic Report of the International Lepidoptera Survey

We present an analysis of the names proposed by Carl Plötz in 1884 for the New World species in the genus Pyrgus Hübner, [1819] facilitated by the genomic sequencing of extant primary type specimens comparatively with a larger sample of more recently collected specimens of these species and their relatives. The changes to nomenclature suggested here are only caused by the identity of primary type specimens as revealed by their phenotypes or though genomic sequencing. All neotypes are designated to stabilize nomenclature in agreement with the current usage of these names, which in unison agrees best with the information available …

Genomic Dna Sequencing Reveals Two New North American Species Of Staphylus (Hesperiidae: Pyrginae: Carcharodini), Jing Zhang

The Taxonomic Report of the International Lepidoptera Survey

Two new skipper butterfly (Hesperiidae) species are described from the United States: Staphylus floridus Grishin, sp. n. (type locality in Florida, Volusia County) and Staphylus ecos Grishin, sp. n. (type locality in Texas, Brewster County). They are cryptic and hence escaped recognition. They differ from their sister species by the relative size and morphology of genitalia and by genotype—including and beyond the COI barcode—thus, suggesting genetic isolation that argues for their species-level status. A lectotype is designated for Helias ascalaphus Staudinger, 1876. Staphylus opites (Godman & Salvin, 1896), stat. rest. is a species-level taxon and not a synonym of Staphylus …

Spatiotemporal Factors Affecting The Occupancy And Phenology Of A Declining Songbird (Bachman's Sparrow - Peucaea Aestivalis) At The Western Extent Of Its Range, Liam G. Wolff

Electronic Theses and Dissertations

The Bachman’s Sparrow (Peucaea aestivalis) is a declining songbird that occurs throughout the southeastern United States. Bachman’s Sparrow is a Species of Greatest Conservation Need in Texas, but information crucial to management efforts, such as factors affecting their detectability and occupancy, is lacking. I investigated the predictors of Bachman’s Sparrow occupancy and phenology in Texas using detections from autonomous recording units coupled with site characteristics and weather data. My results indicate that Bachman’s Sparrow occupancy is associated with increasing herbaceous ground cover and decreasing basal area, distance to the nearest source population, and basal area when canopy height …