Terrestrial and Aquatic Ecology Commons^™

Alliaria Petiolata (M.Bieb.) Cavara & Grande [Brassicaceae], An Invasive Herb In The Southern Ozark Plateaus: A Comparison Of Species Composition And Richness, Soil Properties, And Earthworm Composition And Biomass In Invaded Versus Non-Invaded Sites, Jennifer D. Ogle

Graduate Theses and Dissertations

Invasive species are widely recognized as organisms that severely alter ecosystem processes in the habitats to which they are introduced. Alliaria petiolata is one of the most important invasive plants in forests of the northern United States. This study examined the geographic distribution of the plant in the southern Ozarks, as well as the effect that it may be having on natural processes within forests of the region by comparing plant species richness, plant cover, and soil properties in invaded and non-invaded plots. It was found that A. petiolata is not significantly altering species richness, cover, or soil properties in …

A Fatty Acid Based Bayesian Approach For Inferring Diet In Aquatic Consumers, Aaron W. E. Galloway, Michael T. Brett, Gordon W. Holtgrieve, Eric J. Ward, Ashley P. Ballantyne, Carolyn W. Burns, Martin J. Kainz, Doerthe C. Muller-Navarra, Jonas Persson, Joseph L. Ravet, Ursula Strandberg, Sami J. Taipale, Gunnel Alhgren

Ecosystem and Conservation Sciences Faculty Publications

We modified the stable isotope mixing model MixSIR to infer primary producer contributions to consumer diets based on their fatty acid composition. To parameterize the algorithm, we generated a ‘consumer-resource library’ of FA signatures of Daphnia fed different algal diets, using 34 feeding trials representing diverse phytoplankton lineages. This library corresponds to the resource or producer file in classic Bayesian mixing models such as MixSIR or SIAR. Because this library is based on the FA profiles of zooplankton consuming known diets, and not the FA profiles of algae directly, trophic modification of consumer lipids is directly accounted for. To test …

Fuels And Fires Influence Vegetation Via Above- And Belowground Pathways In A High-Diversity Plant Community, Paul R. Gagnon, Heather A. Passmore, Matthew Slocum, Jonathan A. Myers, Kyle E. Harms, William J. Platt, C.E. Timothy Paine

Biology Faculty Research

1. Fire strongly influences plant populations and communities around the world, making it an important agent of plant evolution. Fire influences vegetation through multiple pathways, both above- and belowground. Few studies have yet attempted to tie these pathways together in a mechanistic way through soil heating even though the importance of soil heating for plants in fire-prone ecosystems is increasingly recognized.
2. Here we combine an experimental approach with structural equation modelling (SEM) to simultaneously examine multiple pathways through which fire might influence herbaceous vegetation. In a high-diversity longleaf pine groundcover community in Louisiana, USA, we manipulated fine-fuel biomass and monitored the …

Investigations Of Larval Pacific Lamprey Entosphenus Tridentatus Osmotic Stress Tolerance And Occurrence In A Tidally-Influenced Estuarine Stream, Gregory Shell Silver

Dissertations and Theses

Pacific lamprey is a culturally valuable species to indigenous people, and has significant ecological importance in freshwater and marine ecosystems. Over the past several decades, constrictions in range and reductions in Pacific lamprey abundance have been observed in Western North America, and may be indicators of range-wide declines. In the face of declining populations, the U.S. Fish and Wildlife Service has partnered with tribal, state, federal, and local entities to implement a regional Pacific lamprey conservation agreement aimed at reducing threats to Pacific lamprey and improving their habitats and population status. Research needs identified in the conservation agreement include assessing …

Tolerance Of The Invasive New Zealand Mud Snail To Various Decontamination Procedures, Christopher N. Acy

Lawrence University Honors Projects

In an attempt to stop the spread of invasive species, state governments have established decontamination procedures for use on contaminated equipment. However, different species can tolerate various procedures depending on their morphology and physiology. The New Zealand mud snail (Potamopyrgus antipodarum) is invasive to the United States and may alter the food web of streams due to the snail’s high reproductive ability, causing potential problems for native trout populations and local economies. We collected mud snails from the recently invaded Black Earth Creek, WI and tested their tolerance to decontamination protocols being considered by the Wisconsin Department of …

Diel Vertical Migration Of An Invasive Calanoid Copepod, Eurytemora Affinis, In Little Sturgeon Bay, Wisconsin, Alexandra N. Poli

Lawrence University Honors Projects

Eurytemora affinis, a calanoid copepod, is known to be a versatile, prolific invader of freshwater ecosystems across the globe. It has recently been documented in the Laurentian Great Lakes, including in Little Sturgeon Bay, an embayment of Lake Michigan. One survival mechanism that could make E. affinis a successful invader is diel vertical migration (DVM), a behavior in which animals move to different lakes depths at different times of day in order to avoid predation. Much is known about DVM of E. affinis, but primarily from studies in marine and brackish systems. Our goal was to investigate how …

An Analysis Of Juvenile Chinook Salmon Outmigration Speed And Survival In Response To Habitat Features: Sacramento River From Knights Landing To Sacramento, California, Natalie N. Mcnair

Master's Theses

Outmigration is an important life stage for Chinook salmon (Oncorhynchus tshawytscha) survival in the Sacramento River, and yet our understanding of their behavior and needs during this time is limited. To gain a better understanding of their survival and movement rates during outmigration, late fall run Chinook salmon smolts were tracked using acoustic telemetry techniques. Habitat features were measured and quantified throughout the study area to evaluate how Chinook salmon respond to key levee features including shade, instream woody material, and aquatic vegetation. The overall average movement speed through the entire study area was 0.77 m/s with an …

The Characterization Of A Vital Wisconsin Waterway: A Biological Assessment Of The Lower Fox River From 2006-2014, Emily L. Kiehnau

Lawrence University Honors Projects

The Lower Fox River has historically been used as a navigational crossroads, a waste disposal system, and source of hydroelectric power. Over the years, heavy use of the river has negatively affected water quality and the overall health of the system. Unhealthy rivers cannot function properly. Biological assessment based on animal surveys are often used to determine river health. I used data from the Lawrence University and Fox River Navigational System Authority invasive species-monitoring project to explore how the distribution of animals in the Fox River has changed over time and across locations. Monitoring surveys have taken place between June …

Reproductive Ecology And Hatchling Behavior Of Olive Ridley Sea Turtles In Honduras, Noemi Duran Royo

Loma Linda University Electronic Theses, Dissertations & Projects

In this dissertation, I investigated the reproductive ecology and hatchling behavior of the olive ridley (Lepidochelys olivacea) sea turtle population nesting in Pacific Honduras. I begin by reviewing olive ridley reproduction, human use of this species, and past and present conservation on nesting beaches. I also propose a conservation strategy to improve nesting beach conservation programs in developing countries. In the first of four empirical studies, I used microsatellite markers to assess multiple paternity levels of the Honduran population, and found evidence for multiple paternity in 75% of the nests examined. This rate, higher than expected for a population of …

Microsatellite Analysis Of Population Structure In The Santa Ana Speckled Dace (Rhinicthys Osculus), Stacey A. Nerkowski

Electronic Theses, Projects, and Dissertations

Rhinichthys osculus, the Speckled Dace, is one of the most ubiquitous fish in western North America. Within the Southern California region, the local taxon is known as the Santa Ana Speckled Dace. The purpose of this study was to characterize and identify polymorphic microsatellite markers for R. osculus in which twenty-three were identified through Illumina pair-end sequencing. Seven of these loci were then used to examine the patterns of genetic variation and population structure that occurred within and among the watersheds in the Southern California. The study also examined the regional relationships among Southern California, Central California and Owen’s …

Predation In A Natural Community Of Marine Mollusks: Using Morphology To Determine Predator-Prey Ecology, Danielle N. Araiza, Erica Valdez

DePaul Discoveries

Predatory gastropod mollusks in the family Naticidae feed on bivalve mollusks and leave distinctive markings in the form of countersunk circular boreholes on the shells. These boreholes possess both an inner borehole diameter (IBD) and an outer borehole diameter (OBD) which are proportional to the size of the predator. It has been proposed that the ratio of IBD to OBD can be used to identify predator species. Variation in the ratio of the IBD to OBD was examined in two prey species (Dwarf surf clam, Incongruous ark clam) collected from Otter Island beach in South Carolina to determine if clams …

A Comparison Of Plot-Based Satellite And Earth System Model Estimates Of Tropical Forest Net Primary Production, Cory C. Cleveland, Philip Taylor, K. Dana Chadwick, Kyla Dahlin, Christopher E. Doughty, Yadvinder Malhi, W. Kolby Smith, Benjamin W. Sullivan, William R. Wider, Alan R. Townsend

Ecosystem and Conservation Sciences Faculty Publications

Net primary production (NPP) by plants represents the largest annual flux of carbon dioxide (CO₂) from the atmosphere to the terrestrial biosphere, playing a critical role in the global carbon (C) cycle and the Earth’s climate. Rates of NPP in tropical forests are thought to be among the highest on Earth, but debates about the magnitude, patterns, and controls of NPP in the tropics highlight uncertainty in our understanding of how tropical forests may respond to environmental change. Here, we compared tropical NPP estimates generated using three common approaches: (1) field-based methods scaled from plot-level measurements of plant …

The Response Of Zooplankton Communities In Montane Lakes Of Different Fish Stocking Histories To Atmospheric Nitrogen Deposition Simulations, Jeffrey Thomas Brittain

Dissertations and Theses

Freshwater ecosystems are subject to a wide variety of stressors, which can have complex interactions and result in ecological surprises. Non-native fish introductions have drastically reduced the number of naturally fishless lakes and have resulted in cascading food web repercussions in aquatic and terrestrial habitats. Additional anthropogenic influences that result from increases in global airborne emissions also threaten wildlife habitat. Atmospheric nitrogen deposition has been recognized as an anthropogenic contributor to acidification and eutrophication of wilderness ecosystems. Planktonic communities have shown declines in response to predation and shifts in composition as a result of nutrient inputs and acidification, both of …

Local Patterns In Host-Selection By Anemone Symbionts In Bocas Del Toro, Panama, Samantha Mercer

Undergraduate Honors Theses

The associations made between many symbiotic cleaner shrimps and their host anemone species are influenced by local ecological factors, resulting in regional variations in symbiont-host preferences. These relationships are crucial parts of aquatic ecosystems, and as we face rapid global environmental change, understanding the local patterns of this host specificity will be essential to maintaining healthy marine environments. However, sea anemones, as well as their symbiotic relationships, from the Caribbean coasts of Panama have been poorly studied and are largely under-represented in the current literature. The purpose of this study is to identify the local host-selection patterns, specifically regarding host-size …

Effects Of Ecologically Realistic Heating Profiles On Feeding In The Intertidal Hermit Crab, Pagurus Sameulis, Paige Davis

Student Scholar Symposium Abstracts and Posters

The intertidal zone is an ideal habitat to investigate effects of global warming because species living in it are very close to their physiological limits. Initial studies of invertebrate physiological responses to heat stress have employed relatively abrupt increases in temperature. My research investigates effects of ecologically more realistic temperature profiles on feeding in the intertidal hermit crab, Pagurus sameulis. Recent work in the Wright lab showed that feeding in this species is inhibited by an abrupt increase in temperature. Because temperature change in the natural environment of Pagurus is much more gradual, I hypothesize that such a gradual temperature …

Effects Of El Niño On Ecological Growth Along Californian And Peruvian Coasts, Alexandra Sidun

Student Scholar Symposium Abstracts and Posters

This study examines the mechanisms of El Niño to further understand the ecological effects it may have along the Californian and Peruvian coasts. El Niño is the warm phase of the El Niño Southern Oscillation (ENSO). While it is a global phenomenon, these two locations were investigated for their nearly equal and opposite conditions during storm months. California, which is in an extreme state of drought, often receives heavy rainfall during El Niño and understanding its potential effects is crucial. El Niño causes upwellings along the CA coast and warm water from the region displaces the normally cool waters along …

Biological Degradation Of Acetaldehyde In Southern California Coastal Waters, Mary Senstad, Sovanndara Hok, Ori Barashy, Catherine D. Clark, Warren J. De Bruyn

Student Scholar Symposium Abstracts and Posters

Oxygenated hydrocarbons are ubiquitous in the atmosphere with levels ranging from low ppt (acetaldehyde) to low ppb (methanol). As an OH sink and an atmospheric HOx and ozone source, oxygenated hydrocarbons have a direct impact on the oxidative capacity of the atmosphere. The oceans are one of the largest sources of uncertainty in current atmospheric budget estimates of these species. A better understanding of the processes that produce and destroy these species in seawater would improve our understanding of the role of the oceans in cycling these species into or out of the atmosphere. We have measured the degradation rate …

Possible Precursor Events To Earthquakes And The Resulting Effects On Organic Material In The Surrounding Water Bodies, Kiyoko Nakatsui

Student Scholar Symposium Abstracts and Posters

Being located on the “Ring of Fire” Japan experiences many seismic events. Adding to this, it is located at the convergence of four fault lines where seismic activity will be even more frequent and severe. Although small tremors occurring in an area are indicators of an earthquake to come it only gives minutes of warning. Scientists are now trying to see if latent heat and gas release from fault lines can indicate an earthquake to come with hours or even days of warning. MODIS aqua and terra data will be analyzed in order to see if such precursors can be …

Puffs And Tufts: A Comparison Of Trichodesmium Colony Formations And Nutrient Availability Across The North Atlantic Ocean Using Remote Sensing Methods, Marc Rosenfield

Student Scholar Symposium Abstracts and Posters

Trichodesmium, a genus of diazotrophic bacteria, has the capability and the population to produce a large percentage of the total oceanic N2-fixation. Though their population is known to be heavily dependent on two of the ocean’s largest limiting factors, phosphorus and iron concentrations, it is unknown what affect these factors have on the population. In this study two of the largest colony formations of Trichodesmium in the North Atlantic, tufts and puffs, are compared nutrient quality with respect to time and geographical location. Though very little nutrient in situ data was collected from the cruise, remote sensing data collected from …

Assessing Water Quality In The Gulf Of Mexico Using Remote Sensing Data., Alliyah Thomas

Student Scholar Symposium Abstracts and Posters

Hypoxia, or oxygen depletion, is a process that occurs in conjunction with eutrophication. In hypoxic conditions the dissolved oxygen levels in the water column sink to unlivable conditions for the marine organisms causing them to flee or die. Despite efforts of improvement, the annual summer Gulf of Mexico dead zone continues to be a serious threat to aquatic ecosystems. The 2012 smaller than usual dead zone was a false indicator of future improvement. The 2012 dead zone decrease was connected to the drought and inability of large amounts of runoff to flow into the gulf. Water quality analysis was done …

Effects Of Human Recreational Activity On The Tameness Of Common Loons (Gavia Immer) In Northern Wisconsin, Seth Yund

Student Scholar Symposium Abstracts and Posters

The Common Loon (Gavia immer) is an aquatic diving bird that lives in freshwater habitats in Canada and the northern U.S.. Human activity on a loon’s resident lake may affect its fitness and behavior, yet few studies identify or quantify these effects. We modified existing techniques that measure escape distances in other species to measure tameness as the distance at which individual loons dove in response to human approach by canoe. Tameness was similar between pair members, suggesting that common lake conditions or the behavior of a mate might influence the behavior. Sex, size within sex, and human activity did …

Evaluation Of Temperature Anomalies And Ocean Productivity During The 2004 Sumatra-Andaman Earthquake, Cora Byers, Brenna Mcnabb

Student Scholar Symposium Abstracts and Posters

The oceanic productivity of the Indian Ocean and temperature anomalies prior to the Sumatra-Andaman earthquake (MW =9.3) and tsunami (December 26th 2004) were studied. Data was obtained via NASA’s Giovanni program to determine the effect on phytoplankton (primary producers) and temperature changes over the region of the earthquake. Seasonal trends were visible in the concentrations of chlorophyll a, coccolithophores, cyanobacteria, chlorophytes, diatoms and absorption coefficient, in addition to storm trends.

Comparing Pseudo-Environmental And Horizontal Plus Pseudo-Environmental Transmission Of A Probiotic Janithinobacterium Lividum Between Green Frog Tadpoles, Stephen Simonetti

Senior Honors Projects, 2010-2019

The gram-negative bacteria, Janthinobacterium lividum (J.liv) is able to kill the pathogenic fungus known as Batrachochytrium dendrobatidis (Bd), which is known to be causing massive amphibian decline worldwide. The purpose of this research was to identify the ability of the probiotic bacteria, Janthinobacterium lividum (J.liv), to be horizontally transmitted from individual to individual and/or pseudo-environmentally transmitted from individual to environment and back to individual between Lithobates clamitans (green frog) tadpoles. Based on previous findings I hypothesized that pseudo-environmental and horizontal transmission will occur in tadpoles. This would be important for helping stop the decline of amphibians because it would provide …

Comparative Analysis Of Anti-Bd Bacteria From Six Malagasy Frog Species Of Ranomafana National Park, Kelsey Savage

Senior Honors Projects, 2010-2019

As Malagasy amphibians are facing an impending extinction crisis from the lethal skin fungus Batrachochytrium dendrobatidis (Bd), it has become imperative to proactively mitigate the threat. Bd sporangia develop in the skin of infected amphibians and cause the skin to thicken, leading to ionic imbalance and eventual heart failure. It has been shown that certain bacterial species are able to inhibit Bd growth on amphibians by producing antifungal metabolites. Community-based probiotics are one approach used to combat chytridomycosis by inoculating an environment with Bd-inhibitory bacteria so that many amphibian species are treated at once. With this method, it is important …

Fishing For A Sustainable Future: Aquaponics As A Method Of Food Production, Richard Ramsundar

Student Theses 2015-Present

This thesis compares and explains the advantages aquaponics farming has over modern industrial intensive farming. Through a comparison natural capital usage, conservation, recycling and cost, the thesis advocates for the expansion of aquaponics usage in urban settings. The thesis also explains the history of intensive farming and aquaponics in America, the science of how aquaponics operates, the economic and environmental costs of modern intensive farming versus aquaponics farming, and the social implications of aquaponics. Lastly, I propose a policy that reallocates farm subsidies by modifying the Farm Bill. Then I propose policies that support creating a new standard of farm …

Using Capture-Mark-Recapture Techniques To Estimate Detection Probabilities & Fidelity Of Expression For The Critically Endangered James Spinymussel (Pleurobema Collina)., Alaina C. Esposito

Masters Theses, 2010-2019

The critically endangered James Spinymussel (Pleurobema collina) is a species of freshwater mussel endemic to Virginia’s James and Dan River basins. In the last 20 years, P. collina has experienced a substantial decline in numbers and currently occupies approximately 10% of its original habitat; however, little information is known about this species to assist in conservation. A 230-meter reach of transitional habitat in Swift Run was selected for repeat observations to estimate detection probabilities using a Capture-Mark-Recapture framework. In June 2014, visual scouting began to locate and tag P. collina (including other mussels in the community) with PIT …

Analysis Of Relationships Between Water Quality Parameters And Stream Sediment With Fecal Bacteria In Hidden Creek, Rock Hill, Sc, Kaitlin J. Mcculloch

Graduate Theses

Hidden Creek, in Rock Hill, SC is in need of a watershed management program to decrease fecal coliform counts by 19% because currently, water samples measured for fecal bacteria exceed the Total Maximum Daily Load (TMDL). One objective of this study was to locate the area/s along Hidden Creek with the highest fecal bacteria counts. The other objectives were to determine whether relationships existed between fecal bacteria and water quality parameters and whether the stream sediment was serving as a reservoir for fecal bacteria. Five sampling sites were established and samples were taken every 1- 2 weeks from June – …

Forest Sustainability In An Altered Landscape Requires Human Intervention, Adam C. Labatore

Biology Theses

Recruitment success determines the abundance and composition of plant communities. Successful recruitment can be summarized as a simple dichotomy of establishment versus seed limitations. Establishment limitation occurs when plant populations are inhibited by habitat availability and quality, whereas seed limitation occurs when seeds fail to arrive in necessary densities. Recruitment failure undermines overstory sustainability if the existing trees cannot replace themselves. Preliminary analysis indicated tree recruitment failure at an urban nature preserve with too few tree seedlings to replace mature canopy trees. These data suggested that the urban forest was not sustainable. The overarching goal of the study was to …

Observations On The Life History Of The Bayou Killifish, Fundulus Pulvereus (Everman 1899) In Mississippi Tidal Marshes, Leah Corrine Gaines

Master's Theses

This study provides insight into the life history of the relatively unknown intertidal marsh fish Fundulus pulvereus (Everman), the bayou killifish. Monthly sampling for F. pulvereus took place in three different Mississippi tidal marshes over a period of 17 months (n=445). Observations on the diet, parasite fauna, and fecundity of the bayou killifish were documented on all specimens collected. Percent Occurrence and Percent Number coupled along with multivariate analyses indicated seasonal, site, and ontogenetic shifts in the diet of F. pulvereus. Dominant prey items consumed by F. pulvereus were copepods, mites, chironomids, and terrestrial and aquatic insects. The bayou …

Effects Of Pre-Release Physical Stressors On Post-Release Success Of Hatchery-Reared Spotted Seatrout, Taylor Westbrook Guest

Master's Theses

Alteration of habitat associated with coastal development and increased demand for food and recreation can result in the depletion of fisheries resources such as the Spotted Seatrout (Cynoscion nebulosus), the Gulf of Mexico’s most popular recreational fish. Stock enhancement, or the release of cultured fish to supplement wild populations, is one potential tool for managing important fisheries resources. Although much effort has gone into marine stock enhancement, the effectiveness of stocking is not well established, and techniques for ensuring success have not been developed. Although the basic biology of the Spotted Seatrout is well known, comparatively little is known about …