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A Socio-Economic Assessment Of Marine Turtle Eco-Tourism, Kendra Cope

Electronic Theses and Dissertations

Marine turtles have historically contributed to economic activity through consumptive harvest for food, tools, and decorative objects. Only recently have they begun to benefit humans economically through non-consumptive roles, primarily as a focal point of educational eco-tourism. In recent years, the annual number of turtle walks conducted around the Archie Carr National Wildlife Refuge (ACNWR) has risen. This expansion contributed to a statistically significant increase in attendance from 2,162 in 2001 to 3,047 participants in 2014. I examined the regional economic impacts of marine turtle eco-tourism around the ACNWR using social surveys and an economic impact analysis tool. IMPLAN, an …

The Influence Of Diet Composition, Plant Defensive Chemicals, And Winter Severity On The Nutritional Condition Of A Freeranging, Generalist Herbivore, Grace L. Parikh

Dissertations, Master's Theses and Master's Reports - Open

Herbivory requires animals to manage intake of toxic phytochemicals. Detoxification and excretion of these chemicals prevents toxicity, but is energetically expensive. I investigated the relationship between investment in detoxification and nutritional condition for moose on Isle Royale National Park (Alces alces) during winter, using urinary indices from urine samples collected in snow. The ratio of urinary urea nitrogen:creatinine is an indicator of nutritional condition, and the ratio of glucuronic acid:creatinine is an indicator of investment in detoxification. Nutritional condition declined with greater investment in detoxification. An alternative means of managing defensive chemical intake is to diversify the diet. Microhistological …

Interactive Effects Of Climate Change And Fungal Communities On The Decomposition Of Wood-Derived Carbon In Forest Soils, Samantha L. Mosier

Dissertations, Master's Theses and Master's Reports - Open

Soils are the largest sinks of carbon in terrestrial ecosystems. Soil organic carbon is important for ecosystem balance as it supplies plants with nutrients, maintains soil structure, and helps control the exchange of CO₂ with the atmosphere. The processes in which wood carbon is stabilized and destabilized in forest soils is still not understood completely. This study attempts to measure early wood decomposition by different fungal communities (inoculation with pure colonies of brown or white rot, or the original microbial community) under various interacting treatments: wood quality (wood from +CO₂, +CO₂+O₃, or ambient …

Climate Anomalies And Primary Production In Lake Superior, Marcel L. Dijkstra

Dissertations, Master's Theses and Master's Reports - Open

This dissertation supports the modeling of primary production in Lake Superior by offering site specific kinetics and algorithms developed from lab experiments performed on the natural phytoplankton assemblage of Lake Superior. Functions, developed for temperature, light and nutrient conditions and the maximum specific rate of primary production, were incorporated in a 1D specific primary production model and confirmed to published in-situ measured rates of primary production.

An extensive data set (supporting model calibration and confirmation), with a fine spatiotemporal resolution, was developed from field measurements taken bi-weekly during the sampling seasons of 2011, 2012 and 2014; considered to be meteorologically …

Ecophysiological Responses Of Sugar Maple Roots To Climatic Conditions, Mickey Philip Jarvi

Dissertations, Master's Theses and Master's Reports - Open

The severity of future climate change resulting from anthropogenic alteration of the global C cycle will depend in part on feedbacks between atmospheric greenhouse gases and forest ecosystem carbon balance, but how these two systems will interact is not entirely understood. Forests are both major sinks and sources for atmospheric CO₂ through the processes of photosynthesis and ecosystem respiration. The balance between these two processes could be altered if autotrophic respiration were to increase exponentially with temperature as climate warms. Root respiration, and especially fineroot respiration (<1 mm diameter), is a major contributor to total ecosystem C exchange. A study to assess long-term responses of root respiration to warmer soil conditions was conducted at the SMART (sugar maple altered rainfall and temperature) experiment located in Alberta, MI at the Michigan Technological University’s Ford Center and Forest. It was found that acclimation of fine-root respiration in this system was not due to an insufficient supply of carbohydrates from photosynthesis (substrate limitation), but was the result of adenylate control. As a result, fine root respiration was constrained to levels needed to perform work required of the fine roots (e.g. nutrient acquisition). Acclimation also occurred for roots 1-2 mm in diameter at the 0-10 cm soil depth, but not in any roots larger than 2 mm or in roots of any size at deeper soil depths. As a result, at the ecosystem level, total root system respiration was 60% greater in warmed soil than in unwarmed soil. The studies in experimentally warmed sugar maple forests were complemented by an examination of fine-root respiration and root biomass at sixteen sugar maple forests located across a latitudinal gradient across sugar maple’s native range, spanning approximately 10°C of mean annual temperature. Sugar maple in the southern, warmer sites had lower root N, lower specific fine-root respiration at a given temperature, and less fine-root biomass than that from the northern cooler regions. Fine root respiration at ambient soil temperature actually decreased from north to south, despite a nearly 10°C increase in soil temperature. However, within sites respiration measured across three sample dates did increase with temperature. The next big question is whether these adjustments that exist across sugar maple’s range are plastic responses to l local climate or result from genotypic differences among populations in different locations. If the former is true, all sugar maple would be capable of acclimation, reduction in root biomass, and/or reduction in root N as mechanisms for dealing with climatic warming, and sugar maple would have a large capacity to adjust to future climate change. The latter would suggest that predicted rates of climatic warming could have negative impacts on this important species across its entire current range. The lack of changes in fine root biomass and root N concentration at the SMART study location after four plus years of soil warming support the possibility that differences along the latitudinal transect are largely the result of inherent genetic differences among population.

Movement Of Bigmouth Sleeper, Gobiomorus Dormitor, In The Río Cañas, Puerto Rico, Revealed By Radio Telemetry, And A Discussion Of The Species’ Amphidromous Characterization, Steve E. Lochmann, Christine Adelsberger, J. Wesley Neal

Gulf and Caribbean Research

Bigmouth Sleeper, Gobiomorus dormitor, are tropical fish native to rivers of Puerto Rico. They are popular sport fish targeted by local anglers. They are considered as diadromous, but this characterization is controversial. The displacement of Bigmouth Sleepers in the Río Cañas, Puerto Rico, was examined using radio telemetry. Twenty fish were radio-tagged and monitored from January to November 2008. Fish were in the Río Cañas 69%, 62%, and 59% of the time before (January-May), during (June-August), and after (September-November) the spawning season, respectively. Average detected linear home range (within the river) for all tracking periods was 2.3 km, but …

Impact Of Development On Freshwater Turtle Populations Of Coastal South Carolina: An Examination Of Land Use And Road Density, Andre Dominguez

Electronic Theses and Dissertations

Previous studies (Haxon 2000; Steen and Gibbs 2004; Marchand and Litvaitis 2004; Aresco 2005) have demonstrated that urbanization and development have disproportionally adverse affects on female turtles. In order to test this paradigm I caught 301 turtles (primarily Trachemys scripta scripta) in ten ponds (5 impacted and 5 unimpacted) across coastal South Carolina. Not only do coastal South Carolina turtles not follow the same male biased pattern of many other studies, there was an overall female bias (154:95). Turtle metrics were between the types of sites existed as well, indicating larger/older population of turtles in unimpacted sites. Water quality parameters …

Tide-Dependent Predation Patterns Of Piscivorous Fishes In Shallow Estuarine Creeks, Matthew Ross Helms

Electronic Theses and Dissertations

The distribution and foraging behavior of predatory salt marsh fishes is shaped by the movements of prey, many of whom seek shelter in shallow and tributary creeks. I hypothesized that the distribution of piscivorous fishes in marsh creek channels would differ with proximity to the mouths of intertidal creeks and with tidal stage. Custom-built trotlines baited with live minnows were deployed during four discrete tidal stages at two microhabitats in main creek channels: (1) adjacent to intertidal creek mouths, and (2) along straight banks in North Inlet estuary, South Carolina. Catch-per-unit-effort of predatory fishes was significantly higher (Wilcoxon signed-rank tests, …

Cows And Plows: Science-Based Conservation For Grassland Songbirds In Agricultural Landscapes, Marisa K. Lipsey

Graduate Student Theses, Dissertations, & Professional Papers

Temperate grasslands are among earth’s most imperiled ecosystems. In North America, steep declines of endemic songbird populations indicate that grassland loss and degradation may be approaching critical levels. Grasslands are agricultural landscapes largely (~85%) under private ownership with little formal protection status. Remaining bird populations depend on grazing lands that have not been converted to cropland. We combine regional data from a hotspot for grassland bird diversity (northeast Montana, USA; 26,500-km2) with continental data spanning the northern Great Plains (1,000,000-km2) to evaluate how land use and management influence bird distribution and abundance. Regionally, habitat used by seven grassland specialists spanned …

Sun-Compass Orientation During Natal Dispersal In Hatchling Blanding's Turtles (Emydoidea Blandingii), Meredith Anne Schlenner

All Graduate Theses, Dissertations, and Other Capstone Projects

Blanding's turtle hatchlings emerge from their natal nests naïve to environmental stimuli and primarily sense visual cues on the horizon as a dispersal target. During a period of hours or days, hatchlings develop a compass mechanism that allows them to maintain a direction of travel, even when the target is not visible. We examined the dispersal directions of Blanding's turtle hatchlings captured during dispersal by translocating them into a circular arena in a field of corn in order to measure their dispersal direction guided by a compass mechanism. To test for use of a sun compass, a magnetic compass, or …

Community Perturbation Associated With New Zealand Mudsnail (Potamapyrgus Antipodarum) Invasion: Discrepancies In Temporal And Spatial Assessment, Eric H. Richins

Graduate Student Theses, Dissertations, & Professional Papers

Invasive species have the potential to alter the ecosystems within which they establish as well as adjacent but uninvaded ecosystems by altering the flow of nutrients or biota across system boundaries. New Zealand mudsnails (Potamopyrgus antipodarum; NZMS) are often very abundant where they invade, sequestering the majority of stream primary production. This sequestering of production may reduce aquatic insect production, subsequent insect emergence and subsidies to riparian ecosystems. Tetragnathid spiders, an insectivorous riparian specialist, are dependent on the emergence of aquatic insects and are typical indicators of aquatic insect subsidies to riparian zones. In addition, NZMS invasions can result …

Effects Of Prescribed Fire On Upland Plant Biodiversity And Abundance In Northeast Florida, Peter D. Maholland

UNF Graduate Theses and Dissertations

Terrestrial ecosystems in the southeastern United States have evolved with fire as a common disturbance and as a result many natural communities require the presence of fire to persist over time. Human development precludes natural fires from occurring within these communities; however, prescribed fire is considered to be a critical tool in the effort to restore fire-dependent ecosystems after decades of fire exclusion. Direct effects of fire on individual floral and faunal species as well as benefits to biodiversity at the landscape (gamma diversity) level have largely been supported in previous research. However, information on the effects of natural and …

An Assessment Of The Role Of Roads In Population Demography And Genetic Structuring In Two Species Of Lizards In The Northern Chihuahuan Desert, Kevin Floyd

Open Access Theses & Dissertations

Roads can fragment habitat and increase mortality rates of wildlife, potentially reducing population sizes and gene flow, which in turn can reduce genetic diversity through genetic drift. Although negative road impacts have been found in a variety of taxa, not all species are impacted. For instance, species that move less and rarely encounter roads and those that avoid the roads are predicted to not be negatively affected. Yet tests of these predictions are uncommon, especially for reptiles and particularly lizards. Side-blotched lizards (Uta stansburiana) are small sit-and-wait predators, while the larger marbled whiptails (Aspidoscelis marmorata) are active foragers. Their responses …

Ecological Features Of The Greater Earless Lizard, Cophosaurus Texanus, (Squamata: Phrynosomatidae) On Indio Mountains Research Station, Hudspeth County, Texas, Gabriela Franco

Open Access Theses & Dissertations

626 Cophosaurus texanus were captured on regular trips to Indio Mountains Research Station in Hudspeth County, Texas from August 2010 to November 2014. Mark-recapture methods using 81 pitfall traps and toe-clips for identification allowed for analyses of long-term trends. 291 adult females, 315 males, and 20 unsexed juveniles were recorded. A total of 180 independent recapture events were documented over the study period (44% females; 55% males). The greatest numbers of C. texanus were collected in 2011 (234), which was also the driest year of the four (6.77 cm), whereas 2014 was the wettest (34.95 cm), but had the second-most …

Systematics Of The African River Frog Genus Amietia (Anura: Pyxicephalidae) From Eastern Democratic Republic Of The Congo, Thornton Robert Larson

Open Access Theses & Dissertations

The African river frog genus Amietia is found near rivers and other lentic water sources throughout central, eastern and southern Africa. Because the genus includes multiple morphologically conservative species, taxonomic studies of river frogs have been limited. We sampled 49 individuals of Amietia from multiple localities in and near the Albertine Rift (AR) of Burundi, Democratic Republic of the Congo and Uganda. We utilized single-gene (16S) and concatenated (12S, 16S, cytochrome b and RAG1) gene-tree analyses and coalescent species-tree analyses to construct phylogenetic trees. Two divergence dating approaches were used in BEAST, including secondary calibration points with 12S, 16S and …

Phylogeny And Systematics Of Panaspis And Afroablepharus Skinks (Squamata: Scincidae) In The Savannas Of Sub-Saharan Africa, Maria Fernanda Medina

Open Access Theses & Dissertations

African snake-eyed skinks are relatively small lizards of the genera Panaspis and Afroablepharus. The allocation of these genera was frequently rearranged in the 20th century based on morphology, ecology and biogeography. Members of these genera occur primarily in savanna habitats throughout sub-Saharan Africa and include species that have highly conserved morphology, which poses a challenge for taxonomic studies. We sequenced two mitochondrial (16S and cyt b) and two nuclear genes (PDC and RAG1) from 91 Panaspis and Afroablepharus samples from various localities in eastern, central and southern Africa. Concatenated gene-tree and divergence dating analyses were conducted to infer phylogenies and …

Introduction Effort, Climate Matching And Species Traits As Predictors Of Global Establishment Success In Non-Native Reptiles, Peter J. Mahoney, Karen H. Beard, Andrew M. Durso, Aimee G. Tallian, Arin Lexine Long, Ryan J. Kindermann, Nicole E. Nolan, Daniel Kinka, Harrison E. Mohn

Biology Faculty Publications

Non-native reptiles are often detrimental to native communities and ecosystems and can be extremely difficult to manage once established. Thus, there is considerable interest in predicting the likelihood of establishment of nonnative reptiles. We assessed three hypotheses describing possible factors contributing to the successful establishment of introduced reptiles in an effort to better identify potential invaders.

Stable Isotope Values Delineate The Non-Breeding Distributions Of Sooty Shearwaters Puffinus Griseus In The North Pacific Ocean, David Thompson, Leigh Torres, Graeme Taylor, Matt Rayner, Paul Sagar, Scott A. Shaffer, Richard Phillips, Sarah Bury

Faculty Publications, Biological Sciences

Following breeding, sooty shearwaters Puffinus griseus leave New Zealand waters and migrate to 1 of 3 distinct areas in the North Pacific Ocean, effectively exploiting environmental resources across a large proportion of this northern ocean basin. In this study, we combined electronic tracking technology with stable isotope analyses (δ15N and δ13C) of feathers grown during the non-breeding period in order to evaluate whether isotope signatures can be used to identify specific non-breeding areas used by sooty shearwaters. A region to the east of Japan was utilised by the majority of tracked birds, whereas others used areas off the west coast …

Approximation Of Fire-Return Intervals With Point Samples In The Southern Range Of The Coast Redwood Forest, California, Usa, Gregory Jones, Will Russell

Faculty Publications, Environmental Studies

A legacy of past fires is evident in the form of blackened basal hollows found throughout the southern range of the coast redwood (Sequoia sempervirens [D. Don] Endl.) forest.  A deeper look reveals cambial scars dating back centuries, telling a story of low- to moderate-intensity fires that burned periodically across California’s Central Coast bioregion.  While attempts have been made to reconstruct the fire history of this forest type, estimates of the fire-return interval vary widely, and the relationship of the fire-return interval to varying cultural influences is not fully understood.  We analyzed 373 fire scars from 70 cross-sections removed from …

Anthropogenic Litter And Microplastic In Urban Streams: Abundance, Source, And Fate, Amanda Rae Mccormick

Master's Theses

The accumulation and ecological effects of anthropogenic litter (AL) and microplastic are well-documented in marine ecosystems, but these materials’ abundances in rivers is unknown. AL enters rivers from recreation, runoff, and illegal dumping. Microplastic fibers and pellets are abundant in wastewater treatment plant (WWTP) effluent which enters rivers. Our objectives were to: (1) quantify AL abundance and composition in urban streams, (2) measure AL flux, accumulation, and export, and (3) measure riverine microplastic concentration and analyze its bacterial communities. We collected AL from 5 urban streams and observed greater AL density in riparian habitats and greater mass in benthic habitats. …

Horseshoe Crab Research In Urban Estuaries: Challenges And Opportunities, Jennifer Mattei, Mark L. Botton, Mark Beekey, Christina P. ColóN

Biology Faculty Publications

Horseshoe crabs rely on estuaries for food resources, places to spawn and for larvae and juveniles to develop and grow. Many of these estuaries are becoming increasingly urbanized and dominated by human activity. An urban estuary is characterized by armored shorelines, high nutrient loads, large fluctuations in algal and bacteria populations, increased levels of pollutants like heavy metals and pesticides, and seasonally low oxygen levels and pH. While urban estuaries are challenging for horseshoe crab survival and to researchers trying to study them, there are also opportunities for involving the public in research and increasing public awareness of the importance …

The Mismanagement Of Limulus Polyphemus In Long Island Sound, U.S.A.: What Are The Characteristics Of A Population In Decline?, Mark Beekey, Jennifer Mattei

Biology Faculty Publications

Over the past 15 years, horseshoe crabs in Connecticut have gone from being considered a nuisance species to a species of Greatest Conservation Need in 2015. This has happened through first, its discovery as an economically important species, second through research of its ecological role in coastal estuaries, and third, through education of the public concerning its role in the environment and their own health. To manage horseshoe crab populations successfully requires long term monitoring, research and education. The use of annual or biannual trawl data trends to assess the success of management decisions is limited due to the high …

Physical And Biological Constraints On The Abundance Of Cyanobacteria In The James River Estuary, Brendan C. Trache

Theses and Dissertations

The tidal-fresh James River experiences recurring blooms of toxin-producing cyanobacteria, including Microcystis aeruginosa. However, cyanobacteria cell densities in the James are relatively low. Our purpose was to identify key factors suppressing cyanobacteria growth in the face of eutrophication. A mesocosm experiment was designed to test the effects of light, mixing and grazing on cyanobacteria abundance, with nutrients held constant. We predicted that toxic cyanobacteria would be most abundant under stagnant conditions, with enhanced light, with no bivalve grazers present. Abundances of indicator gene copies and phytoplankton counts supported this hypothesis. However, chlorophyll-a, phycocyanin, and the toxin microcystin were all …

Emergent Non-Consumptive Predator Effects Alter Habitat Colonization By Dipteran Prey, Ethan G. Staats

Theses and Dissertations

When ovipositing, prey organisms avoid habitat patches containing predator cues because predators consume, and negatively affect the fitness of their prey. Richness of predator species often enhances the strength of consumptive predator effects, but little is known about how multiple predators combined affect prey non-consumptively. We quantified dipteran colonization in aquatic mesocosms in response to varied predator richness. Multiple predator species combined reduced oviposition by Culex mosquitoes, chironomid midges, and the general colonizing dipteran community more than predicted by the effects of the independent predator species. Previous research which quantifies effects of multiple predators on prey as prey abundance, but …

Consequences Of Vine Infestation: Linking Abiotic Influences And Biotic Interactions To Successional And Structural Changes In Coastal Communities, Spencer N. Bissett

Theses and Dissertations

Located at the interfaces of terrestrial and marine environments, coastal habitats are inherently vulnerable to the effects of global change. Barrier island systems in particular serve not only as protective buffers against storm events, but also as sentinel ecosystems for observation of the impacts of sea level rise, and of increasing storm frequency and intensity. In the mid-Atlantic region, shrub thickets of Morella species compose the dominant forest community. The often monospecific nature of these plant community assemblages is advantageous to ecological studies and cross-scale applications; the relatively low diversity facilitates transitions between scales. My objective was to investigate the …

Effects Of Constant Vs. Fluctuating Temperatures On Performance And Life History Of The Herbivorous Pest Lymantria Dispar (Lepidoptera: Eribidae), Brendan E. Sostak

Theses and Dissertations

The role of temperature variation in organismal performance is understudied, but is critically important for understanding the response of biodiversity to climate change. To address this issue in herbivorous insects, I studied the direct and interactive effects of thermal regime (constant vs. fluctuating temperatures) and nutrition (dietary nitrogen) on gypsy moth (Lymantria dispar) performance under laboratory conditions. Predictions for differences between constant and fluctuating thermal conditions were derived from Jensen’s inequality, and artificial diets of differing nutritional quality were made by modifying nitrogen (casein) content. Larvae were reared in the laboratory under four temperature regimes (22°C constant, 22°C …

Expanding Eco-Visualization: Sculpting Corn Production, Jennifer E. Figg

Theses and Dissertations

This dissertation expands upon the definition of eco-visualization artwork. EV was originally defined in 2006 by Tiffany Holmes as a way to display the real time consumption statistics of key environmental resources for the goal of promoting ecological literacy. I assert that the final forms of EV artworks are not necessarily dependent on technology, and can differ in terms of media used, in that they can be sculptural, video-based, or static two-dimensional forms that communicate interpreted environmental information. There are two main categories of EV: one that is predominantly screen-based and another that employs a variety of modes of representation …

Behavioral Responses Of Male Parasitic Wasps To Plant Cues: A Comparison Of Two Host-Plant Complex Sources Of Cotesia Congregata (Say), Megan Ayers

Theses and Dissertations

Prior exposure to plants cues can enhance assortative mating in insects. We hypothesized that, as previously reported for females, males of Cotesia congregata would display inherent responses to plant cues that could be modified by postemergence experience and further, that males originating from two different host-plant complexes (HPCs) would display different behavioral responses to these HPCs. In no-choice contact assays with a non-host plant, searching responses of males and females increased sharply at Day 2 and remained stable through Day 4. In no-choice assays with potential host plants, males searched longer on catalpa than tobacco; responses were not modified by …

Responses Of The Catalpa Sphinx, Ceratomia Catalpae, And Its Primary Parasitoid, Cotesia Congregata, To Varying Levels Of Iridoid Glycosides In Catalpa, Jessica L. Bray

Theses and Dissertations

The catalpa sphinx, Ceratomia catalpae, is a specialist on Catalpa trees, which produce iridoid glycosides (IGs). Whereas some trees are defoliated every year, others escape herbivory. Caterpillar populations are either heavily parasitized by the braconid wasp, Cotesia congregata, or remain unparasitized. We hypothesized that these patterns could be explained by variable IG concentrations among trees and insect responses to these chemicals. IG concentrations varied among trees. Percent defoliation was positively related to IG concentration. In comparisons of insect responses to relatively high or low IG concentrations, moths preferred to oviposit on trees with high IG concentrations. Caterpillars did …

Toxic Cyanobacteria Aerosols: Tests Of Filters For Cells, Sean R. Perry, Alexis Mack, James F. Haney, Amanda Murby

Honors Theses and Capstones

Aerosolization of toxic cyanobacteria released from the surface of lakes is a new area of study that could uncover a previously unknown route of exposure to toxic cyanobacteria. Since toxic cyanobacteria may be responsible for adverse human health effects, methods and equipment need to be tested and established for monitoring these airborne bacteria. The primary focus of this study was to create controlled laboratory experiments that simulate natural lake aerosol production. I set out to test for the best type of filter to collect and analyze the aerosolized cells as small as 0.2-2.0 µm, known as picoplankton. To collect these …