Terrestrial and Aquatic Ecology Commons^™

Sugar Maple (Acer Saccharum Marsh.) Tree-Ring Growth And Carbon Stable Isotope Responses To Nitrogen And Climate, Libbie Ring

Dissertations, Master's Theses and Master's Reports

This dendrochronological and stable carbon isotope study used tree rings from sugar maple (Acer Saccharum Marsh.) collected at long-term nitrogen (N) amended sites throughout Michigan to understand N amendment and deposition, climate, and growth relationships. Climate responses varied by site, however, we found importance in grouping sites by “productivity” which is related to inherent N and soil nutrients. Our results did not detect an overall effect of N amendments on growth during the treatment period. However, data shows N amendments benefiting larger diameter trees, while smaller diameter trees responded more positively without amendments, especially on more productive sites. Results …

Seasonal Occupancy Of The Thermal Plume Of A Spring Tributary To The South Fork Roanoke River, Virginia., Steven L. Powers, Michael M. Calvert, Charlotte M. Spaulding

Southeastern Fishes Council Proceedings

Detection of temperate stream fishes varies widely across seasons as streams teeming with life in summer often appear empty during winter sampling efforts. While much literature documents the disproportionate use of the thermal plumes of spring tributaries by cold water fishes during summer, few studies have investigated occupancy of those habitats by warm water fishes in winter. We conducted quantitative snorkeling observations within the near uniform temperatures (10-14^oC) of the thermal plume of a spring tributary to the South Fork Roanoke River across seasons and compared number of fishes observed and species richness to control observations made just …

Co2 In Flowing Freshwaters: Macro Scale Database Compilation, Addressing Ph Bias In Co2 Estimates, And Quantifying Cross-Scale Interactions, Timothy R. Toavs

LSU Doctoral Dissertations

This dissertation focuses on carbon dioxide (CO₂) dynamics in flowing freshwaters, contributing to the growing body of knowledge about inland water carbon cycles. The research is structured into three main chapters, each progressing towards the objective of utilizing variability in flowing freshwaters to further understand carbon dynamics, anthropogenic land cover impacts, and potential impacts from a changing climate. Chapter one compiles a 30-year dataset of pCO₂ measurements from flowing freshwater systems across the contiguous United States. This dataset, referred to as CDFLOW, includes over 750,000 pCO₂ estimates from more than 35,000 locations. It serves …

Native Freshwater Mussel Communities In The Lower Grand River, Michigan: Assessing Tributary Confluence Effects And Updating Survey Information, Grayson L. Kosak

Masters Theses

Freshwater mussels (Unionidae) are ecosystem engineers and keystone species vital to stream ecosystems yet represent the most imperiled group of freshwater fauna. Conservation of unionids necessitates further understanding how assemblages interact with watershed features. This study investigates mussel occupancy, distribution, and assemblage structure upstream and downstream of tributary confluences in the lower Grand River, Michigan, alongside updated surveys of the unionid community with comparisons to previous assessments conducted by Michigan Natural Features Inventory (MNFI) in 2002–2003. Unionid density, richness, and diversity were greater upstream of confluences. No significant distance-gradient effects were observed. Assemblage structure differed between upstream and downstream reaches …

Social Learning And Cultural Enrichment For Fish Welfare, Chiawen Chiang, Becca Franks

Animal Sentience

This commentary examines how understanding animal culture—shared behaviors and knowledge transmitted through social learning—plays a role in advancing welfare practices for captive fishes. Despite extensive evidence of fishes' complex sociocultural capacities, their psycho-social needs remain underestimated and unmet in zoos and aquaria. We explore what considering fish culture might mean for welfare practices: diverse social learning opportunities, cultural development, and thoughtful group management. More knowledge about wild fishes' lives will help bridge the gap between their full, complex lives and current captive welfare practices.

Invasion Stress Mitigates Climate Stress In A Brackish Marsh Amphipod, Lorna E. Haworth, Sarah Nancollas, Susie N. Landa, Anne E. Todgham, Richelle L. Tanner

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

1. Organisms in coastal brackish ecosystems face not only highly variable environmental conditions, but the intensity and stochasticity of these environmental conditions are anticipated to increase due to climate change. While environmental changes are often presented unilaterally as stressors, there are some anthropogenic environmental transformations, such as the introduction of habitat forming plant species, that may mitigate physiological stress imposed by warming. In Suisun Marsh in the California Delta, native plant canopies allow light and heat to penetrate to the understory yet the canopies of the introduced Phragmites australis reed block out sunlight and heat for organisms living below.
2. We set …

Bat Activity Across Urban Forest Plantings In Lexington, Kentucky, Grayson Marie Collier

Online Theses and Dissertations

Urbanization has led to major forest loss and negatively impacts ecosystem services. Urban reforestation efforts, such as Reforest the Bluegrass (RTB) in the Lexington-Fayette metropolitan area of Kentucky, have been implemented to address these negative effects, and to create habitat for forest-dependent wildlife such as bats. My research focused on assessing differences in bat activity across a 20-year chronosequence of RTB sites. Acoustic detectors were deployed across 10 different-aged plantings at 60 randomly-defined detector locations. Each planting was surveyed across 8 sampling periods from May – August 2023. Each recording session spanned ca. 7 consecutive nights, yielding a total of …

Cyperus Blepharoleptos Maxent Ecological Niche Models, Samuel A. Schmid, Maxwell G. Gebhart, Gray Turnage

GRI Publications

Invasive species are one of the foremost threats to global biodiversity and predicting where they can inhabit is of primary concern for researchers and resource managers. Ecological niche models (ENMs) are a useful tool for addressing this problem. This study focuses on Cyperus blepharoleptos (Cuban bulrush), an aquatic sedge that is invasive in the southeastern United States. To model the ecological niche of C. blepharoleptos, 1,137 records were compiled from North and South America and partitioned into training and testing data. Five BioClim variables (BIO1, BIO7, BIO12, BIO14, and BIO15) were selected as environmental variables for modeling. Using Maxent, 12 …

Spatiotemporal Patterns In Orbicella Faveolata Wound Regeneration As An Indicator Of Colony Health, Alexander G. Wheeler

All HCAS Student Capstones, Theses, and Dissertations

Anthropogenic (e.g. damage from anchors, scuba divers, tissue sampling) and natural disturbances (e.g. predation, storm damage) can result in wounding of live tissue on coral colonies. Wounding has been shown to detract from a common resource pool, increasing disease susceptibility and impairing coral growth and reproductive activity. Regeneration not only varies between species, but also between conspecifics in the same location. A colony’s capacity to regenerate tissue can be an indicator of a colony’s condition and resilience. Understanding the physiological and environmental factors that affect tissue regeneration alongside the ultimate impact of sampling (disease and predation correlations) are needed for …

Spatial Ecology Of Large Bodied Ichthyofauna In The Red River Of The North Basin, William Marshall Stuart

School of Natural Resources: Dissertations, Theses, and Student Research

Understanding spatial patterns and processes is essential for designing research studies, implementing management actions, and planning restoration efforts. The Red River of the North basin spans a broad geographic area where jurisdictional oversight is divided among several entities (Manitoba, CAN; North Dakota, USA; Minnesota, USA; South Dakota, USA), creating a mosaic of regulatory and functional process zones. Understanding the spatial ecology of freshwater fishes in this disjointed landscape is essential to address diverse life history requirements and the movement constraints imposed by anthropogenic structures. Long-term acoustic telemetry revealed that large bodied ichthyofauna employ a diverse range of movement strategies (i.e., …

The Influence Of Wind Energy Development On Occupancy Of Medium And Large-Sized Mammals In South Texas, Elwynn Sherman

Theses and Dissertations

Conservation paradigms have shifted from single to multi-species approaches for assessing and conserving mammalian populations and the habitats that they occupy. The effect of wind turbine development is an important anthropogenic change to study due to the increasing demand for wind energy in Texas. In this study, I gathered remote camera trap data on medium and large-sized mammal populations in south Texas Tamaulipan thornscrub habitat. The objectives were to determine species presence, the effect of habitat characteristics and anthropogenic disturbances on species occupancy, and the effect of temperature on species detection. The results showed that distance from wind turbines did …

Comparing Metabolism And Hypoxia Tolerance Of Native And Non-Native Florida Freshwater Fishes In Climate Change Scenarios, Benjamin A. Share

All HCAS Student Capstones, Theses, and Dissertations

As climate change brings rising water temperatures and lower dissolved oxygen (DO) concentrations to freshwater bodies, it has become increasingly important to understand how this will affect ecosystems with established non-native or invasive species. Fishes of the family Cichlidae are the most pervasive non-native fishes in the Everglades and may increase their range further north under a changing climate. To better understand potential invasibility and competition with native fishes, the metabolism and hypoxia tolerance of non-native Blue Tilapia Oreochromis aureus was compared to native Bluegill Lepomis macrochirus when acclimated across a range of seasonal and projected temperatures. Intermittent-flow respirometry was …

Bioindicators Of Mercury In Riverine Systems, Kathryn Mudica

All-Inclusive List of Electronic Theses and Dissertations

This study focuses on the bioaccumulation and biomagnification of mercury in freshwater food webs, with emphasis on bioindicators, such as macroinvertebrates, crayfish, and river otters. Despite regulatory efforts and advancements in monitoring, significant gaps remain in understanding mercury dynamics in freshwater systems—especially regarding its transport, methylation, and bioavailability across different ecosystems. To address these knowledge gaps, this study adopts a biocentric approach, emphasizing the role of living organisms in their environment. By utilizing macroinvertebrates, crayfish, and river otters as bioindicators, we aim to assess mercury bioavailability and distribution. These organisms provide varying temporal and spatial scales of mercury accumulation, offering …

Investigating The Acute Physiological Effects Of Effluent Crystal Violet On The Freshwater Bioindicator Daphnia Pulex, Hoang K. Ho

2024 Fall Honors Capstone Projects - Archive

This study examines the effects of acute exposure to crystal violet (CV) on the freshwater zooplankton Daphnia pulex in response to growing concerns over synthetic dyes from industrial runoff in aquatic ecosystems. The primary objective is to assess CV's impact on D. pulex's heart rate, mobility, morphology, and lethality via a series of acute exposure tests. 48-h acute toxicity (0-2000 μg/L), 48-h immobilization (0-180 μg/L), and 9-h heart rate (0-2,000 μg/L) tests were conducted using third-generation daphnids, followed by stereomicroscopic examination and statistical analysis. Results showed increasing mortality and decreasing mobility and heart rate with increasing CV concentration; the …

Evaluating The Success Of A Relocated Mussel Community In The Lower Sulphur River, Texas, Rachel M. Leicher

Biology Theses

Conservation efforts to preserve freshwater mussel communities have become more common as these animals become increasingly threatened by their changing habitats. As humans continue to shape and change the world around them, aquatic species living in modified and disturbed water systems can be negatively impacted leading to decline of the ecosystem. During disturbance events involving a stream, river, or pond, the relocation of affected mussel beds is becoming more widespread. Although there are few of these studies, many of those that have been conducted are seen as successful in relocating and conserving their mussel communities. This study focuses on detection …

Frogs On A Plain: Spatial Ecology Of Crawfish Frogs In Arkansas’ Remnant Prairies, Elliot T. Lassiter

Graduate Theses and Dissertations

The prairie peninsula was an expansive and important habitat that covered much of midwestern North America, from Canada to Arkansas, USA. But the prairie peninsula has shrunk by as much as 99% since 1830, and therefore, land acquisition and public/private partnerships are critical for the preservation of prairies and their associated species. In Arkansas, one species that benefits from protected prairies is the Crawfish Frog (Lithobates areolatus), which is currently declining precipitously throughout its range. Adult Crawfish Frogs spend most of their lives in terrestrial refugia (crayfish burrows), making them highly vulnerable to habitat loss and fragmentation, thereby …

Influence Of Hydrologic And Anthropogenic Disturbance On Stream Populations And Communities, Sarah Frances Sorensen

Graduate Theses and Dissertations

Disturbances occur when an external force modifies a habitat, destroying living space, removing food resources, or altering or destroying habitat structure. In lotic systems, a primary source of disturbance is hydrologic disturbance, including drought and flood. Hydrologic disturbances lead to increased mortality rates and dispersal out of disturbed habitats, causing population sizes to decrease and changes to community structures. More research is needed on how disturbances impact stream species and communities, as disturbances are predicted to become more intense with climate change. This dissertation aims to understand how disturbance influences streams at both the population and community level, through a …

Investigating Nekton Response To Changing Salinities In The Mississippi Sound: An Experimental And Statistical Approach, Adam Murray

Master's Theses

The Mississippi Sound provides nursery habitats for many coastal species and is recognized for its commercial fisheries. Previous freshening events linked to the Bonnet Carré Spillway, a Mississippi River flood diversion structure, proved catastrophic for oyster populations in the Mississippi Sound, but effects on mobile fish and shellfish species are not well-defined. The planned Mid-Breton Sediment Diversion (MBSD), an initiative to combat wetland loss, is also forecasted to lower salinities in the region, increasing the need to better understand responses of commercially and ecologically important species to freshening events. The objective of this study was to characterize effects of salinity …

Phytoplankton Responses To Changing Irradiance And Carbon Fertilization, Alison Siersma

Graduate Theses and Dissertations (2019 - present)

Phytoplankton play a crucial role in marine ecosystems due to their innate ability to fix carbon. As atmospheric CO2 levels continue to rise from fossil fuel combustion, the resulting increase in dissolved CO2 and the concurrent decrease in ocean pH are likely to impact the phytoplankton community. The response of phytoplankton to elevated CO2 can vary significantly among species and environmental conditions (e.g. light, temperature, nutrient availability). To address these variations, an experiment was conducted using a controlled photobioreactor system, maintaining high and low light, constant temperature, nutrient levels, and two pCO2 concentrations. This study focused on two regionally relevant …

Time Series Decomposition Of Land Surface Temperature For Long-Term Trend Forecasting And Impact On Nesting Sea Turtle Habitats In The Arabian Gulf, Sachi Perera, Rommel H. Maneja, Mohamed Allali, Cyril Rakovski, Erik Linstead, Daniele Struppa, Ali Qasem, Hesham El-Askary

Mathematics, Physics, and Computer Science Faculty Articles and Research

Improving land surface temperature (LST) modeling is vital for mitigating climate change effects on various ecosystems and marine habitats such as important sea turtle habitats. Over the past decade, extreme temperatures have likely significantly affected nesting sea turtle habitats in the Arabian Gulf, with predominantly female hatchlings creating an imbalance in the sex ratio. Such shifts have profound implications for these habitats’ long-term survival and conservation management. This study leverages statistical machine learning models to measure ongoing temporal variations in LST. We break down the LST time series into trend, seasonal, and noise components using classical decomposition methods like X11, …