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Full-Text Articles in Life Sciences

An Assessment Of The Diverse Freshwater Turtle Fauna Of Mississippi, Lucas Haralson Dec 2021

An Assessment Of The Diverse Freshwater Turtle Fauna Of Mississippi, Lucas Haralson

Master's Theses

Nestled within the Southeastern United States Turtle Priority Area, Mississippi boasts impressive freshwater turtle diversity and is home to 8.6% of extant turtle species. Despite this impressive richness, few studies have assessed freshwater turtle assemblages in this hotspot of aquatic diversity. This research aimed to elucidate the distributions and abundances of freshwater turtle species through a statewide investigation of all major river drainages of the state. Using baited hoop nets (90 cm and 120 cm diameter), turtles were collected, identified to species and sex, and measured, before being released. Turtle assemblages were assessed in both lotic and lentic environments from …


Distribution, Abundance, And Population Genetics Of The Alligator Snapping Turtle (Macrochelys Temminckii) In Mississippi, Luke Pearson Dec 2021

Distribution, Abundance, And Population Genetics Of The Alligator Snapping Turtle (Macrochelys Temminckii) In Mississippi, Luke Pearson

Dissertations

The southeastern United States is a freshwater turtle biodiversity hotspot, second only to southeastern Asia, and this region is inhabited by one of the largest freshwater turtles in the world: the alligator snapping turtle (Macrochelys temminckii). This species was heavily harvested from the 1960’s to the 1980’s for the turtle soup industry, apparently contributing to substantial, range-wide population declines. These declines, coupled with anthropogenic impacts on riverine and floodplain habitats, have led to M. temminckii being petitioned for federal listing under the U.S. Endangered Species Act; it is currently under review by the U.S. Fish and Wildlife Service …


Testing For Character Displacement Between Two Abundant Stream Fishes, Amber Nations Aug 2021

Testing For Character Displacement Between Two Abundant Stream Fishes, Amber Nations

Honors Theses

Character displacement is a pattern that can be used to explain differences between similar species in sympatric and allopatric situations. Gause’s Principle explains that a niche can only be occupied by one species at a time, so character displacement may be a way for similar species in the same habitat to shift resource use and compensate in order for the species to coexist. The Southeastern United States offers a unique opportunity to study this pattern because the diversity of freshwater fauna is quite high. However, the question of “How did this region become so diverse?” remains unanswered. One way for …


Brown Meets Green: Light And Nutrients Alter Detritivore Assimilation Of Microbial Nutrients From Leaf Litter, Taylor L. Price, Jennifer Harper, Steven N. Francoeur, Halvor M. Halvorson, Kevin A. Kuehn Jun 2021

Brown Meets Green: Light And Nutrients Alter Detritivore Assimilation Of Microbial Nutrients From Leaf Litter, Taylor L. Price, Jennifer Harper, Steven N. Francoeur, Halvor M. Halvorson, Kevin A. Kuehn

Faculty Publications

In aquatic detrital-based food webs, research suggests that autotroph-heterotroph microbial interactions exert bottom-up controls on energy and nutrient transfer. To address this emerging topic, we investigated microbial responses to nutrient and light treatments during Liriodendron tulipifera litter decomposition and fed litter to the caddisfly larvae Pycnopsyche sp. We measured litter-associated algal, fungal, and bacterial biomass and production. Microbes were also labeled with 14C and 33P to trace distinct microbial carbon (C) and phosphorus (P) supporting Pycnopsyche assimilation and incorporation (growth). Litter-associated algal and fungal production rates additively increased with higher nutrient and light availability. Incorporation of microbial P …


Trophic Ecology Of Mesopelagic Fish Larvae And Juveniles In The Northern Gulf Of Mexico, Emily Gipson May 2021

Trophic Ecology Of Mesopelagic Fish Larvae And Juveniles In The Northern Gulf Of Mexico, Emily Gipson

Master's Theses

The deep-pelagic environment encompasses ocean waters below 200 m depth, and comprises 90% of the volume of the Gulf of Mexico. Deep-pelagic fishes are important prey for many oceanic consumers, but relatively little is known about their early life history, including larval fish trophic ecology. An understanding of the role deep-pelagic fish larvae have in oceanic food webs is important in the development of ecosystem models that examine the connectivity (via vertical migrations) between the deep-pelagic and epipelagic environments with respect to trophic interactions, nutrient cycling, and carbon sequestration. In this study, archived plankton samples collected during 2010 and 2011 …


Modeling Hydrochemical And Vegetation Responses Of High-Elevation Forested Watersheds To Future Climate And Atmospheric Deposition Changes In The Southeastern U.S., Hailong Huang May 2021

Modeling Hydrochemical And Vegetation Responses Of High-Elevation Forested Watersheds To Future Climate And Atmospheric Deposition Changes In The Southeastern U.S., Hailong Huang

Dissertations

Changes in climate and atmospheric acidic deposition alter biogeochemical cycles in forested ecosystems. I investigated the responses of vegetation, soil, and hydro-related processes to changes in climate and acidic deposition at five high-elevation forests in the southeastern U.S. using a biogeochemical model - PnET-BGC model. I focused on change-points and thresholds concepts that were less studied in forest ecosystems as well as seasonal variability of responses and extreme events. I applied principal component analysis (PCA) to reduce the dimensionality of data. I developed a Bayesian multi-level model to derive key biogeochemical variables response to temperature and precipitation (local) and latitude …


Effects Of Nutrient Management Scenarios On Marine Food Webs: A Pan-European Assessment In Support Of The Marine Strategy Framework Directive, Chiara Piroddi, Ekin Akoglu, Eider Andonegi, Jacob W. Bentley, Igor Celić, Marta Coll, Donna Dimarchopoulou, René Friedland, Kim De Mutsert, Raphael Girardin, Elisa Garcia-Gorriz, Bruna Grizzetti, P. Y. Hernvann, Johanna J. Heymans, Bärbel Müller-Karulis, Simone Libralato, Christopher P. Lynam, Diego Macias, Svetla Miladinova, Fabien Moullec, Andreas Palialexis, Ove Parn, Natalia Serpetti, Cosimo Solidoro, Jeroen Steenbeek, Adolf Stips, Maciej T. Tomczak, Morgane Travers-Trolet, Athanassios C. Tsikliras Mar 2021

Effects Of Nutrient Management Scenarios On Marine Food Webs: A Pan-European Assessment In Support Of The Marine Strategy Framework Directive, Chiara Piroddi, Ekin Akoglu, Eider Andonegi, Jacob W. Bentley, Igor Celić, Marta Coll, Donna Dimarchopoulou, René Friedland, Kim De Mutsert, Raphael Girardin, Elisa Garcia-Gorriz, Bruna Grizzetti, P. Y. Hernvann, Johanna J. Heymans, Bärbel Müller-Karulis, Simone Libralato, Christopher P. Lynam, Diego Macias, Svetla Miladinova, Fabien Moullec, Andreas Palialexis, Ove Parn, Natalia Serpetti, Cosimo Solidoro, Jeroen Steenbeek, Adolf Stips, Maciej T. Tomczak, Morgane Travers-Trolet, Athanassios C. Tsikliras

Faculty Publications

Eutrophication is one of the most important anthropogenic pressures impacting coastal seas. In Europe, several legislations and management measures have been implemented to halt nutrient overloading in marine ecosystems. This study evaluates the impact of freshwater nutrient control measures on higher trophic levels (HTL) in European marine ecosystems following descriptors and criteria as defined by the Marine Strategy Framework Directive (MSFD). We used a novel pan-European marine modeling ensemble of fourteen HTL models, covering almost all the EU seas, under two nutrient management scenarios. Results from our projections suggest that the proposed nutrient reduction measures may not have a significant …


Swimming Against The Flow: Environmental Dna Can Detect Bull Sharks (Carcharhinus Leucas) Across A Dynamic Deltaic Interface, James Marcus Drymon, Katherine E. Schweiss, Emily A. Seubert, Ryan N. Lehman, Toby S. Daly-Engel, Mariah Pfleger, Nicole M. Phillips Jan 2021

Swimming Against The Flow: Environmental Dna Can Detect Bull Sharks (Carcharhinus Leucas) Across A Dynamic Deltaic Interface, James Marcus Drymon, Katherine E. Schweiss, Emily A. Seubert, Ryan N. Lehman, Toby S. Daly-Engel, Mariah Pfleger, Nicole M. Phillips

Faculty Publications

© 2020 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd Human activities in coastal areas are accelerating ecosystem changes at an unprecedented pace, resulting in habitat loss, hydrological modifications, and predatory species declines. Understanding how these changes potentially cascade across marine and freshwater ecosystems requires knowing how mobile euryhaline species link these seemingly disparate systems. As upper trophic level predators, bull sharks (Carcharhinus leucas) play a crucial role in marine and freshwater ecosystem health. Telemetry studies in Mobile Bay, Alabama, suggest that bull sharks extensively use the northern portions of the bay, an estuarine–freshwater interface known …


Timing Of Predation Risk During Early Development Influences Oyster Shell Morphology, Armorel Eason, Andrew B. Powell, Sarah H. Roney, Carter Lin, Christa M. Russell, Benjamin A. Belgrad, Delbert Lee Smee Jan 2021

Timing Of Predation Risk During Early Development Influences Oyster Shell Morphology, Armorel Eason, Andrew B. Powell, Sarah H. Roney, Carter Lin, Christa M. Russell, Benjamin A. Belgrad, Delbert Lee Smee

Gulf and Caribbean Research

No abstract provided.


Elevating Dissolved Oxygen—Reflections On Developing And Using Long-Term Data, Nancy N. Rabalais Jan 2021

Elevating Dissolved Oxygen—Reflections On Developing And Using Long-Term Data, Nancy N. Rabalais

Gulf and Caribbean Research

This prospectus took me about as long to generate as my 36—year record of working on the issue of northern Gulf of Mexico (nGOM) oxygen deficiency, or so I felt. There was so much to cover, but I focused on the issue of hypoxia on the Louisiana continental shelf from the early 1980s to present and my participation in the research and outreach. Not that I was ignoring other aspects of my academic research career (e.g., stone crab populations and their differences in physiology and larval development along the nGOM coast; settlement of crab megalopae, especially blue crabs, on artificial …


Oldest Indo-Pacific Lionfish (Pterois Volitans/P. Miles) Recorded From The Northwestern Gulf Of Mexico, Raven D. Blakeway, Alexander Q. Fogg, Glenn A. Jones Jan 2021

Oldest Indo-Pacific Lionfish (Pterois Volitans/P. Miles) Recorded From The Northwestern Gulf Of Mexico, Raven D. Blakeway, Alexander Q. Fogg, Glenn A. Jones

Gulf and Caribbean Research

Indo-Pacific lionfish (Pterois volitans/miles) were first detected off the coast of Florida in the 1980s, with aquaria release being the most likely mechanism for introduction. Since then, lionfish have proliferated through the Western Atlantic Ocean, Caribbean Sea, and Gulf of Mexico (GOM). Here, we report the oldest lionfish aged on record in the Western Atlantic, removed from Flower Garden Banks National Marine Sanctuary (FGBNMS) in the GOM. In August 2018, a research expedition removed 745 lionfish from FGBNMS, of which a subset were retained for age and growth estimation. The oldest lionfish was a 10 y old male, …


Patterns Of Dispersion, Movement And Feeding Of The Sea Urchin Lytechinus Variegatus, And The Potential Implications For Grazing Impact On Live Seagrass, Adrianna Parson, Joseph M. Dirnberger, Troy Mutchler Jan 2021

Patterns Of Dispersion, Movement And Feeding Of The Sea Urchin Lytechinus Variegatus, And The Potential Implications For Grazing Impact On Live Seagrass, Adrianna Parson, Joseph M. Dirnberger, Troy Mutchler

Gulf and Caribbean Research

The sea urchin Lytechinus variegatus is a known grazer of both living and dead tissue of turtlegrass, Thalassia testudinum, occasionally denuding large areas of seagrass. Field studies have attempted to assess effects of herbivory on seagrass by enclosing urchins at various densities. However, it is unclear how unrestricted urchins affect seagrass at lower densities more typically observed in the field. This study describes movement, feeding, and distribution of L. variegatus within beds of T. testudinum in St. Joseph Bay, Florida (USA) to quantify this urchin’s impact as a seagrass grazer. Urchins were absent from portions of seagrass beds closest to …


How A Simple Question About Freshwater Inflow To Estuaries Shaped A Career, Paul A. Montagna Jan 2021

How A Simple Question About Freshwater Inflow To Estuaries Shaped A Career, Paul A. Montagna

Gulf and Caribbean Research

Chance and good luck led to a career studying how freshwater inflow drives estuary processes. In 1986, someone asked me: How much fresh water has to flow to a bay for it to be healthy? The question shaped my career. There is probably no better place on Earth to compare effects caused by inflow differences than the Texas coast, because the major estuarine systems lie in a climatic gradient where runoff decreases 56—fold from the Louisiana border in the northeast to the Mexico border in the southwest. This estuary—comparison experiment was used to study inflow effects. The science evolved from …