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Full-Text Articles in Life Sciences

Assessing The Mechanisms And Implications Of Altered Carbon Cycling In Arctic And Boreal Lakes, Rachel Fowler May 2019

Assessing The Mechanisms And Implications Of Altered Carbon Cycling In Arctic And Boreal Lakes, Rachel Fowler

Electronic Theses and Dissertations

Dissolved organic carbon (DOC) is an important component of lake ecology, as it contributes to light attenuation and carbon cycling. In recent years, DOC declined in a suite of lakes in Greenland. I performed experiments to test potential mechanisms of DOC loss. The tested mechanisms did not reduce DOC concentration, but DOC composition was affected. I also paired water quality data with meteorological observations to evaluate effects of climate drivers on lake variables. The lake variables were temporally coherent and associated with patterns of mean annual precipitation.

In the northeastern U.S., recovery from acidification and climate change have contributed ...


Blacklegged Tick (Ixodes Scapularis) Distribution In Maine, Usa, As Related To Climate Change, White-Tailed Deer, And The Landscape, Susan P. Elias May 2019

Blacklegged Tick (Ixodes Scapularis) Distribution In Maine, Usa, As Related To Climate Change, White-Tailed Deer, And The Landscape, Susan P. Elias

Electronic Theses and Dissertations

Lyme disease is caused by the bacterial spirochete Borrelia burgdorferi, which is transmitted through the bite of an infected blacklegged (deer) tick (Ixodes scapularis). Geographic invasion of I. scapularis in North America has been attributed to causes including 20th century reforestation and suburbanization, burgeoning populations of the white-tailed deer (Odocoileus virginianus) which is the primary reproductive host of I. scapularis, tick-associated non-native plant invasions, and climate change. Maine, USA, is a high Lyme disease incidence state, with a history of increasing I. scapularis abundance and northward range expansion. This thesis addresses the question: “To what extent has the range expansion ...


Living On The Edge: Thermophysiology Of The Southern Flying Squirrel At Its Northern Range Margin, Vanessa R. Hensley May 2019

Living On The Edge: Thermophysiology Of The Southern Flying Squirrel At Its Northern Range Margin, Vanessa R. Hensley

Electronic Theses and Dissertations

Climate change has the potential to upset entire ecological systems, making predictive models of the utmost importance. The incorporation of physiological parameters into predictive models not only bolsters their accuracy but also provides a mechanistic explanation for ecological changes already observed and those yet to come. North American flying squirrels, for example, have already experienced dramatic range shifts northward over recent decades, with climate change being the suspected driver. While other studies have focused on warming winter temperatures, I explored the hypothesis that rising summer temperatures were driving the observed range shifts. Unable to find a reliable population of the ...


Ecological And Economic Implications Of Increased Storm Frequency And Severity For Boreal Lakes, Kathryn Warner May 2019

Ecological And Economic Implications Of Increased Storm Frequency And Severity For Boreal Lakes, Kathryn Warner

Electronic Theses and Dissertations

In boreal regions, increased precipitation events have been linked to increased concentrations of dissolved organic carbon (DOC), however less is known about the extent and implications of these events on lakes. We assessed the effects of precipitation events on six drinking water lakes in Maine, USA to better understand how DOC concentration and quality change in response to precipitation events. Our results revealed three types of responses: (1) an initial spike in DOC concentrations and quality metrics; (2) a sustained increase in DOC concentrations and quality metrics and; (3) no change during all sampling periods. Lake residence time was a ...


Thermal And Low Oxygen Tolerance Of A Southern Population Of Striped Bass (Morone Saxatilis), Daniel A. Lleras Jan 2019

Thermal And Low Oxygen Tolerance Of A Southern Population Of Striped Bass (Morone Saxatilis), Daniel A. Lleras

Electronic Theses and Dissertations

Climate change projections estimate a 2-3°C increase in water temperatures by the end of the century. The amount of habitat with suitable temperature and oxygen concentration for aquatic organisms will also be reduced. Striped bass (Morone saxatilis) inhabiting the rivers in Southeastern Georgia make an interesting study system as they do not participate in summer coastal migrations typical of their northern conspecifics. Instead, fish in this southern population remain in freshwater environments that experience warming and decreases in dissolved oxygen. The present study aims to determine the thermal and low oxygen tolerance of juvenile striped bass collected from southeast ...


Impacts Of Ammonia And Temperature On Freshwater Snail Behavior And Physiology., Megan Christine Dewhatley Dec 2018

Impacts Of Ammonia And Temperature On Freshwater Snail Behavior And Physiology., Megan Christine Dewhatley

Electronic Theses and Dissertations

Gastropods are one of the most imperiled groups of animals in North America, yet there are major gaps in the literature pertaining to pollutants and climate change, and especially sublethal impacts. This dissertation assesses the effects of climate warming and unionized ammonia (NH3), one of the most abundant water pollutants, on the behavior and physiology of two caenogastropod snails: fine-ridged elimia (Elimia semicarinata) and Shawnee rocksnails (Lithasia obovata) (Gastropoda: Neotaenioglossa: Pleuroceridae). Righting behavior, or the movement used by snails to turn themselves right-side-up, was used as the main endpoint; delays in this behavior compromise fitness via lost feeding time ...


Developing A Risk Assessment Protocol To Quantify Distribution And Uptake Of Persistent Organic Pollutants In Glacial Outflows, Kimberley Rain Miner May 2018

Developing A Risk Assessment Protocol To Quantify Distribution And Uptake Of Persistent Organic Pollutants In Glacial Outflows, Kimberley Rain Miner

Electronic Theses and Dissertations

Pollutants released by industrialized nations between 1960 and 2004 have been transported northward through atmospheric processes and deposited into glaciated alpine ecosystems. Many of these chemicals retain their original structure and are absorbed into the biota thousands of miles away from where they were originally utilized. With a warming climate increasing the melt of alpine glaciers, these glaciers may be introducing growing amounts of toxins into the watershed. While studies have demonstrated the existence of resident pollutants within glaciated ecosystems, no one has developed a risk assessment to identify sources and quantity of risk posed by these compounds when released ...


Linking Rising Pco2 And Temperature To The Larval Development, Physiology And Gene Expression Of The American Lobster (Homarus Americanus), Jesica Waller Nov 2016

Linking Rising Pco2 And Temperature To The Larval Development, Physiology And Gene Expression Of The American Lobster (Homarus Americanus), Jesica Waller

Electronic Theses and Dissertations

Anthropogenic warming and ocean acidification are occurring as CO2 continues to accumulate in the atmosphere (OA). Few studies have evaluated the joint effects of elevated temperature and partial pressure of CO2 (pCO2)on marine organisms. In this study we investigated the interactive effects of Intergovernmental Panel on Climate Change (IPCC) predicted temperature and pCO2 for the end of the 21st century on key aspects of larval development of the American lobster, Homarus americanus, an otherwise well-studied, iconic, and commercially prominent species in the northeastern United States and Atlantic Canada. Our experiments showed that larvae ...


Ecology Of Largemouth Bass In An Aging Reservoir: Implications For Creating A Trophy Largemouth Bass Fishery, Jason Breeggemann Jan 2016

Ecology Of Largemouth Bass In An Aging Reservoir: Implications For Creating A Trophy Largemouth Bass Fishery, Jason Breeggemann

Electronic Theses and Dissertations

There are an estimated 3-9 million small reservoirs and nearly 1,000 large reservoirs in the United States. Most of these reservoirs were built several decades ago and are experiencing symptoms of reservoir aging, including loss of habitat, sedimentation, and decreased fishery production. Furthermore, over the last several decades, there has been an increasing interest among anglers for high quality, trophy fisheries. However, little is known about exactly how the reservoir aging process affects the ecology and especially growth potential of Largemouth Bass, particularly under potential climate change scenarios. Grand Lake in TX is a 45ha ageing reservoir that was ...


Fish Ladders Designed For Drop Culverts And Central Stoneroller Ecology Across A Latitudinal Gradient, John Arthur Lorenzen Jan 2016

Fish Ladders Designed For Drop Culverts And Central Stoneroller Ecology Across A Latitudinal Gradient, John Arthur Lorenzen

Electronic Theses and Dissertations

Stream connectivity is essential for the persistence of fish populations and maintenance of fish assemblage structure. Stream-road crossings can become barriers resulting in a loss of connectivity. Creating innovative tools for fisheries managers to allow fish passage through barrier stream-road crossings is important worldwide as climate change may force range shifts to stay within thermal requirements. Understanding how populations and metapopulations respond to climate is important as fisheries managers can use this information to make informed management decisions in regards to climate change and possible range shifts. Thus, we developed and tested a fish ladder to retrofit barrier stream-road crossings ...


Identifying Inundation-Driven Effects Among Intertidal Crassostrea Virginica In A Commercially Important Gulf Of Mexico Estuary, Joshua Solomon Jan 2015

Identifying Inundation-Driven Effects Among Intertidal Crassostrea Virginica In A Commercially Important Gulf Of Mexico Estuary, Joshua Solomon

Electronic Theses and Dissertations

Sea level rise and changing storm frequency and intensity resulting from climate change create tremendous amounts of uncertainty for coastal species. Intertidal species may be especially affected since they are dependent on daily inundation and exposure. The eastern oyster Crassostrea virginica is an economically and biologically important sessile intertidal species ranging from Canada to the Gulf of Mexico. Declines and changes in distribution of oyster populations has forced commercial harvesting to spread from subtidal to intertidal reefs. We investigated the potential responses of intertidal C. virginica to sea level rise, and the response of larval settlement to sedimentation which is ...


Sex Ratios Of Juvenile Green Turtles (Chelonia Mydas) In Three Developmental Habitats Along The Coast Of Florida, Cheryl Sanchez Jan 2013

Sex Ratios Of Juvenile Green Turtles (Chelonia Mydas) In Three Developmental Habitats Along The Coast Of Florida, Cheryl Sanchez

Electronic Theses and Dissertations

The concept of temperature dependent sex determination (TSD) has been somewhat of an evolutionary enigma for many decades and has had increased attention with the growing predictions of a changing climate, particularly in species that are already threatened or endangered. TSD taxa of concern include marine turtles, which go through various life stages covering a range of regions. This, in turn, creates difficulties in addressing basic demographic questions. Secondary sex ratios (from life stages post-hatchling) were investigated by capturing juvenile green turtles (Chelonia mydas), 22.6-60.9 cm in straight carapace length (SCL), from three developmental areas along the east ...


Relating Climate Change To The Nesting Phenology And Nest Environment Of Marine Turtles, Monette Schwoerer Jan 2013

Relating Climate Change To The Nesting Phenology And Nest Environment Of Marine Turtles, Monette Schwoerer

Electronic Theses and Dissertations

Ectotherms (including marine turtles) being especially sensitive to climate, are at risk to the accelerated rate of human-driven climate change. This study addresses two concerns associated with marine turtles and climate change – the relationship between the timing of marine turtle nesting and sea surface temperature; and the concern over the feminization of marine turtle populations due to rising sand temperatures. Previous studies of loggerhead sea turtles (Caretta caretta) and green sea turtles (Chelonia mydas) have documented the relationship between sea surface temperatures and nesting phenology. Earlier nesting behaviors in both species have been associated with warmer sea surface temperatures. Also ...


Adaptive Tolerance To Ocean Acidification In The Marine Sponge: Chondrilla Nucula, Sylvester Lee Jan 2012

Adaptive Tolerance To Ocean Acidification In The Marine Sponge: Chondrilla Nucula, Sylvester Lee

Electronic Theses and Dissertations

The dramatic increase in atmospheric carbon dioxide since the Industrial Revolution has led to a 30% increase in ocean acidification over pre-industrial levels. Although most ocean acidification research thus far has focused on calcifying organisms such as corals, the potential of this increase in acidity (H+ ions) to cause acid-base imbalances in soft-bodied animals such as sponges has been grossly overlooked. Furthermore, many studies on ocean acidification have not considered the elevated temperatures that are predicted to accompany future climate change conditions. Sponges are crucial components to coral reef systems, providing food, nutrients, structure, and support. The sponge Chondrilla nucula ...