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Full-Text Articles in Ecology and Evolutionary Biology

Effects Of Acidification And Salinity On Callinectes Sapidus, Mercenaria Mercenaria, And Their Interactions, Katherine Sara Longmire Jan 2020

Effects Of Acidification And Salinity On Callinectes Sapidus, Mercenaria Mercenaria, And Their Interactions, Katherine Sara Longmire

Dissertations, Theses, and Masters Projects

Ocean acidification (OA) coupled with other stressors, will be detrimental at the species and ecosystem levels. Decreased carbonate ion concentrations negatively impact calcifying species, yet the combined effects of OA and other stressors are less well known, and many studies disregard species interactions. Multi-species studies involving OA and other stressors are crucial to comprehend the full threat of OA. Understanding how OA interacts with other stressors to affect species responses is necessary for future management of exploited species in an altered ecosystem. The objectives of my study were to assess: 1) the effects of long-term exposure to decreased pH and …


A Comparison Of Shorebird Habitat Use Between Living Shorelines And Natural Fringing Marshes, Robert Michael Galvin Jan 2020

A Comparison Of Shorebird Habitat Use Between Living Shorelines And Natural Fringing Marshes, Robert Michael Galvin

Dissertations, Theses, and Masters Projects

We examined the use of fringing marshes by herons and shorebirds in the southern portion of Chesapeake Bay. From 13 pairs of natural fringing marshes and nearby, constructed living shoreline marshes, we completed analysis of videos recorded at discrete, 30-minute intervals (dawn, dusk, high tide, low tide) throughout the 2018 and 2019 field seasons (May through August). A total of 684 hours of recording yielded 91 individual observations of birds comprising six species. Spotted Sandpipers (Actitis macularius) were observed most frequently (25), but only at living shoreline marshes. Likewise, 15 of 16 observations of Green Herons (Butorides virescens) were at …


A Mechanistic Understanding Of Range Expansion Of Invasive Blue Catfish In The Chesapeake Bay Region, Vaskar Nepal Jan 2020

A Mechanistic Understanding Of Range Expansion Of Invasive Blue Catfish In The Chesapeake Bay Region, Vaskar Nepal

Dissertations, Theses, and Masters Projects

Blue catfish Ictalurus furcatus is an invasive species of great concern in coastal habitats throughout the eastern United States, inclulding the Chesapeake Bay and its tributaries. In this dissertation, I use field surveys, laboratory experiments and quantitative modeling to provide insights into several aspects of blue catfish biology at the individual level. In chapter 1, I characterize and compare patterns in growth and body condition in blue catfish populations in the James and York river subestuaries during two stages of invasion. Both the mean growth rate and mean body condition of blue catfish declined in the recent period in response …


Speciation Dynamics Of Diverging Allopolyploid Monkeyflower (Mimulus), Caroline Victoria Schlutius Jan 2020

Speciation Dynamics Of Diverging Allopolyploid Monkeyflower (Mimulus), Caroline Victoria Schlutius

Dissertations, Theses, and Masters Projects

Our understanding of speciation has been greatly improved with advances in genomic technology, but most of our knowledge of speciation is still built on research of diploid systems. Polyploids, however, are found in many lineages across the tree of life and exhibit considerably different evolutionary dynamics than diploids. Here, we investigate patterns of population structure and divergence in a system of two allopolyploid species of Mimulus (monkeyflower) that occur sympatrically in Chile: M. luteus and M. cupreus. We find that while the two species have consistent phenotypic differences across the range, they are genetically clustered into a northern and southern …


Within-Flight-Period Dynamics Driven By Phenology And Transect Quality, Not Patch Size Or Isolation, In A Specialist Butterfly, Panoquina Panoquin, Sam Mason Jan 2020

Within-Flight-Period Dynamics Driven By Phenology And Transect Quality, Not Patch Size Or Isolation, In A Specialist Butterfly, Panoquina Panoquin, Sam Mason

Dissertations, Theses, and Masters Projects

As sea levels rise, coastal salt marshes, and the organisms for which they provision, face existential threats. A first step in understanding how projected marsh loss and reconfiguration may impact obligate species is to define their contemporary distribution and temporal shifts in structure using dynamic occupancy models. While occupancy models have commonly been applied to multi-annual butterfly studies, few have investigated population dynamics within a single-season. Here, we used Bayesian dynamic use models to define within-flight-period trends in adult salt-marsh skipper (Panoquina panoquin) use and state change probability. In doing so, we developed and validated a fully-Bayesian test for closure, …


Evaluating The Impacts Of Land Use And Climate Change On The Hydrology Of Headwater Wetlands In The Coastal Plain Of Virginia, Pamela Braff Jan 2020

Evaluating The Impacts Of Land Use And Climate Change On The Hydrology Of Headwater Wetlands In The Coastal Plain Of Virginia, Pamela Braff

Dissertations, Theses, and Masters Projects

Located at the interface between uplands and surface water networks, headwater wetlands act as a natural filter to improve downstream water quality and play a critical role in maintaining the ecological integrity of downstream aquatic ecosystems. Vulnerable to development pressure, as well as indirect impacts from land use and climate change, the loss and alteration of headwater wetlands has been linked to the loss of biodiversity and regional water quality declines worldwide. The overall goal of this dissertation is to address some of the challenges associated with the management and conservation of headwater wetlands in the coastal plain of Virginia …


Predicting The Impacts Of Climate Change On The Sandbar Shark And Cobia, Daniel P. Crear Jan 2020

Predicting The Impacts Of Climate Change On The Sandbar Shark And Cobia, Daniel P. Crear

Dissertations, Theses, and Masters Projects

A changing climate has been identified as a major driver of changes in marine species’ distribution, phenology, and habitat selection in recent decades and is expected to continue to influence these traits. These changes are not only happening in our oceans, but within coastal habitats as well, where waters are susceptible to sudden changes in temperature and oxygen levels are influenced by nutrient inputs. These changes which will likely impact fish species that utilize these areas as nurseries, spawning habitat, or foraging grounds. In this dissertation I consider climate impacts on two important predators, the sandbar shark (Carcharhinus plumbeus) and …


The Epibiont-Host Interaction Between Zoothamnium Intermedium And Estuarine Copepods, Lucia S.L. Safi Jan 2020

The Epibiont-Host Interaction Between Zoothamnium Intermedium And Estuarine Copepods, Lucia S.L. Safi

Dissertations, Theses, and Masters Projects

Ciliates are basal eukaryotes from Phylum Ciliophora that were first described 400 years ago, but their origins date back 800 million years. Such early origins have allowed contemporary ciliates to be remarkably diverse in both their species numbers and ecological adaptations. Peritrichia, a subclass of ciliates, represents an ideal model to study ciliate diversity, as its members display complex phylogenetic relationships and can be epibionts colonizing the body surface of other organisms. Epibiotic relationships are ecologically and evolutionarily important due to the extensive adaptations in epibiont biology to the life cycles of hosts. These relationships are also important for host …