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Terrestrial and Aquatic Ecology

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Articles 511 - 540 of 964

Full-Text Articles in Biology

Age-0 Walleye Growth Rates Following Spiny Water Flea Bythotrephes Longimanus Invasion, Joseph Amundson Jan 2018

Age-0 Walleye Growth Rates Following Spiny Water Flea Bythotrephes Longimanus Invasion, Joseph Amundson

Journal of Earth and Life Science

Within Voyageurs National Park, spiny water flea Bythotrephes longimanus has reduced Lake Kabetogama and Rainy Lake native zooplankton biomass during summer peak by 40-60%. Subsequently, planktivorous age-0 Yellow Perch Perca flavescens growth has decreased. A possible trophic cascade may influence predatory fish growth rates like that of age-0 Walleye Sander vitreus. Using seine net and electrofishing data, age-0 Walleye growth rates were modeled as a linear function of growing degree days (GDD) and the slope was compared between pre- and post-spiny water flea establishment. Nearby Lake Vermilion, assumed to have been unaffected by spiny water flea until 2015 and …

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Burbot Activity In Relation To Light Penetration On Lake Bemidji, Mn, Hunter Weidenborner, Josh Janecek Jan 2018

Burbot Activity In Relation To Light Penetration On Lake Bemidji, Mn, Hunter Weidenborner, Josh Janecek

Journal of Earth and Life Science

Burbot Lota lota is the only freshwater member of the family Gadidae and has a circumpolar distribution in cold-water regions. Information related to Burbot biology is limited in comparison to most fishes. Snow pack depth and ice conditions influence light penetration and therefore primary production levels. Primary production can have cascading effects on higher trophic levels. Therefore, the objective of this study was to observe if light levels penetrating through cleared and covered ice has an effect on Burbot activity in Lake Bemidji, MN. Angling for Burbot occurred for a minimum of 30 four hour sample periods at both cleared …

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Vegetation Community Development After Dam Removal On The Elwha River, Olivia A. Morgan Jan 2018

Vegetation Community Development After Dam Removal On The Elwha River, Olivia A. Morgan

EWU Masters Thesis Collection

The Elwha River is the site of the largest dam removal project in the world to date and serves as a case study for the ecological effects of large dam removal. The 2012-2014 removal of two dams on the Elwha River exposed a cumulative 2.76 km2 of previously inundated surfaces. Environmental conditions including sediment texture and nutrients, slope-aspect, dispersal distance from the river and mature forest, disturbance, and elevation vary widely across the reservoir surfaces, causing significant variation in the plant community. The first objective of my study is to continue a long-term study of the passively restored vegetation community …

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Relationships Between Factors Influencing Biofilm Formation And Pathogen Retention In Complex Rhizosphere Microbial Communities, Aaron Coristine Jan 2018

Relationships Between Factors Influencing Biofilm Formation And Pathogen Retention In Complex Rhizosphere Microbial Communities, Aaron Coristine

Theses and Dissertations (Comprehensive)

Riparian wetlands are unique habitats facilitating all forms of life. The riverbanks of these environments provide ideal conditions for bacteria, plants, and higher organisms. Of particular interest to this research was the variation in microbial community structure at high, intermediate and poor water quality impacted areas. Assessing the capabilities of plants to retain microbial pathogens was identified. Root systems and corresponding soil are ideal locations for bacterial deposition, resulting in attachment at these areas. Biofilm production in these regions is important for long-term establishment, leading to persistence and potential naturalization. Opportunistic pathogens originating from mammalian fecal matter are introduced into …

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Near-Surface Permafrost Ground Ice Characteristics And Ecological And Physical Drivers Of Transient Layer Ice Content In Discontinuous Permafrost, Jason Paul Jan 2018

Near-Surface Permafrost Ground Ice Characteristics And Ecological And Physical Drivers Of Transient Layer Ice Content In Discontinuous Permafrost, Jason Paul

Theses and Dissertations (Comprehensive)

Accelerated climate warming in northern regions is causing permafrost degradation, leading to the reduction of the areal extent of permafrost. Permafrost is the foundation for many northern ecosystems and communities, so its thaw can have important ecological and societal consequences. Thaw of ice-rich permafrost can cause subsidence of the ground surface proportional to excess ice content. Terrain settlement can cause ponding or damage to infrastructure. Following a surface disturbance that removes much of the vegetation cover, a shift in the ground thermal regime can cause an increase in active layer thickness and rapid thaw of the top portion of permafrost. …

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Incorporating Multi-Spectral Imaging Into Long-Term Upland Breeding Bird Monitoring, Kyle William Schumacher Jan 2018

Incorporating Multi-Spectral Imaging Into Long-Term Upland Breeding Bird Monitoring, Kyle William Schumacher

Master's Theses or Doctor of Nursing Practice

Quivira National Wildlife Refuge in Kansas, United States partnered with Fort Hays State University Hays, KS in 2014 to begin a collaborative research project that aimed to develop a long-term monitoring protocol guided by the Comprehensive Conservation Plan for the refuge published in 2013. This plan identified specific wildlife taxa underrepresented in management impact assessments throughout the property. As a result of this plan, surveys were established to monitor interactions between upland breeding birds and the vegetation community. I conducted point count surveys in 2016, 2017, and 2018 for 122 observation points across four transects. I measured seventeen vegetation variables …

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Oyster Reef Restoration: Impacts On Infaunal Communities In A Shallow Water Estuary, Katherine P. Harris Jan 2018

Oyster Reef Restoration: Impacts On Infaunal Communities In A Shallow Water Estuary, Katherine P. Harris

Honors Undergraduate Theses

Oyster reefs are important estuarine ecosystems that provide habitat to many species including threatened and endangered wading birds and commercially important fishes and crabs. Infaunal organisms (i.e. small, aquatic animals that burrow in the sediment) are also supported by oyster reef habitats. Infaunal organisms are critical to marine food webs and are consumed by many important species that inhabit coastal estuaries. However, over the past century 85% of shellfish reef habitats have been lost, making restoration of these areas vital. Due to their important role in coastal food webs, infauna is hypothesized to be a strong indicator of habitat productivity …

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Dna Extraction And Microsatellite Amplification Of Daphnia Pulicaria Resting Eggs: Analysis Of Allele Frequencies Through Time, Anna Ries Jan 2018

Dna Extraction And Microsatellite Amplification Of Daphnia Pulicaria Resting Eggs: Analysis Of Allele Frequencies Through Time, Anna Ries

Departmental Honors Projects

A paleoecological approach allows for the study of genetic change in populations over longer periods of time than would be possible if one were sampling populations from year to year. Daphnia and other cladoceran zooplankton are amenable to this type of study because they produce diapausing embryos (ephippial eggs) when they sexually reproduce, and these resting eggs can remain viable for decades to centuries in lake sediments. This study uses paleoecological methods as well as a new methodology for ephippial DNA extraction and amplification to assay for genetic variation in ephippial eggs obtained from sediments of varying ages from Square …

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Hunter Harvest Effect On The Breeding Bird Population Of Northern Pintail Anas Acuta In North America, Matthew Wang Jan 2018

Hunter Harvest Effect On The Breeding Bird Population Of Northern Pintail Anas Acuta In North America, Matthew Wang

Journal of Earth and Life Science

Hunter harvest and the effects that it can have on population dynamics is a relationship used by wildlife professionals when making management decisions. Hunter harvest can be compensatory or additive on wildlife populations and instances where hunter harvest has been a key role in a population decline, and sometimes demise, is an occurrence studied in wildlife management. Waterfowl numbers in North America have increased 17% since 1960, but during that same time frame the Northern Pintail population has decreased 40%. Hunter harvest data has been recorded by the U.S. Fish and Wildlife Service since 1961, while they have simultaneously been …

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Microbial Community Response To Light And Heavy Crude Oil In Freshwater Systems, Timothy M. Butler Jan 2018

Microbial Community Response To Light And Heavy Crude Oil In Freshwater Systems, Timothy M. Butler

Dissertations, Master's Theses and Master's Reports

With increased demand for oil, there is an increased risk for oil spills in many environments. A number of pipelines transport oil near or across freshwater systems including the Great Lakes. Microbes are capable of breaking down oil and have thus been proposed as tools for oil spill response through bioremediation. There is a need to understand the microbial response to diverse oil types in freshwater environments due to the lack of research into this topic. This study’s main objectives are to understand how the freshwater microbial communities respond to oil, and how the bacterial communities may respond to different …

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Photosynthetic Activity Under Low Light, Danijela Lonco Jan 2018

Photosynthetic Activity Under Low Light, Danijela Lonco

Williams Honors College, Honors Research Projects

Are bacteria capable of undergoing oxygenic photosynthesis under low-light conditions inside of caves? Inside of an Australian cave, Chlorophyll f was recently discovered. This chlorophyll pigment was found to demonstrate the capability for photosynthesis, suggesting that Chlorophyll f extends the spectrum of usable light needed for oxygenic photosynthesis (Lars, 2015). Due to the findings in this study, a team went to Carlsbad Caverns to see if there were any bacteria capable of undergoing oxygenic photosynthesis under low light.

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Predictors Of Fish Assemblage Structure And Dynamics In Atlantic Coastal Plain Streams, Rebecca Scott Jan 2018

Predictors Of Fish Assemblage Structure And Dynamics In Atlantic Coastal Plain Streams, Rebecca Scott

College of Graduate Studies: Theses & Dissertations

Effective management of freshwater fishes requires a mechanistic understanding of the drivers of assemblage composition; in other words, what determines who is where and when. Stream fish assemblages are potentially influenced by environmental factors that act on multiple spatiotemporal scales, but the relative influence of these drivers may vary between geophysically distinct regions. This study sought to determine the patterns and drivers of fish taxonomic and functional assemblage composition in the coastal plain, a region possessing unique hydrologies, faunas, and physiochemical conditions. I addressed this goal using two complementary chapters, both of which utilized environmental and biotic data collected from …

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Comparison Of Three Benthic Macroinvertebrate Passive Sampling Devices For Non-Wadeable Streams, Kelsey A. Laymon Jan 2018

Comparison Of Three Benthic Macroinvertebrate Passive Sampling Devices For Non-Wadeable Streams, Kelsey A. Laymon

College of Graduate Studies: Theses & Dissertations

Rivers and streams provide essential ecosystem services to the degree that the monitoring and maintenance of these systems becomes imperative. Biomonitoring provides managers and policymakers with the tools to make informed decisions, and macroinvertebrates are often the object of biomonitoring because they are ubiquitous in most systems and are known to be good indicators of water quality. However, methods for sampling macroinvertebrates in non-wadeable streams (i.e., large rivers) have not been standardized across states and regions and an established method for macroinvertebrate biomonitoring in large rivers of Georgia is not currently available. My study compared macroinvertebrates collected with three types …

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The Three Creeks Allotment Consolidation: Changing Western Federal Grazing Paradigms, Taylor Payne Jan 2018

The Three Creeks Allotment Consolidation: Changing Western Federal Grazing Paradigms, Taylor Payne

Human–Wildlife Interactions

The federal government owns approximately 47% of all land in the western United States. In the state of Utah, about 64% of the land base is managed by the federal Bureau of Land Management (BLM) and the U.S. Forest Service (USFS). The government has historically issued permits to owners of private lands to allow the owners to graze their livestock on public lands. The permits (allotments) are generally of 10-year duration and allow for an annual season of use. In some cases, continued and repeated historical annual grazing practices may not be ideal for permit holders and their communities nor …

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Avian Community Responses To Bison Grazing In North American Intermountain Grasslands, Danielle A. Fagre Jan 2018

Avian Community Responses To Bison Grazing In North American Intermountain Grasslands, Danielle A. Fagre

Graduate Student Theses, Dissertations, & Professional Papers

Grassland and shrubland songbird species are a guild of conservation concern in North America. Many of these species have experienced severe population declines, due to habitat loss and land use change. This makes the conservation and management of remaining habitat of crucial importance for this guild. Grazing by large herbivores is an ecosystem process in grassland systems, and in North America, one of the major historic grazers was the Plains bison (Bison bison). Bison are considered ecosystem engineers, because they modify habitat to be more or less suitable for other species, such as grassland and shrubland songbirds. Bison …

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Organizational Effects Of Defeminizing Toxicants: Lessons Learned From An Environmental Sentinel Organism, The Fathead Minnow., Jonathan Ali Dec 2017

Organizational Effects Of Defeminizing Toxicants: Lessons Learned From An Environmental Sentinel Organism, The Fathead Minnow., Jonathan Ali

Theses & Dissertations

Endocrine disrupting compounds (EDCs) are chemicals that interfere with hormone function and are increasingly detected in aquatic environments, where they elicit adverse effects from exposed organisms. The toxicological effects of EDCs can be described as either activational (reversible) or organizational (irreversible), where the latter are associated with adverse outcomes in reproductive performance of adult fish. However, few studies have investigated the organizational impacts of anti-estrogenic or “defeminizing” EDCs, e.g. agrichemicals or pharmacological agents, in an environmentally-relevant or “sentinel” species. The objective of this study was to investigate the impacts of early-life EDC-initiated changes in estrogenic gene expression on organizational effects …

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The North American Quails, Partridges, And Pheasants, Paul A. Johnsgard Oct 2017

The North American Quails, Partridges, And Pheasants, Paul A. Johnsgard

Zea E-Books Collection

This book documents the biology of six species of New World quails that are native to North America north of Mexico (mountain, scaled, Gambel’s, California, and Montezuma quails, and the northern bobwhite), three introduced Old World partridges (chukar, Himalayan snowcock, and gray partridge), and the introduced common (ring-necked) pheasant. Collectively, quails, partridges, and pheasants range throughout all of the continental United States and the Canadian provinces. Two of the species, the northern bobwhite and ring-necked pheasant, are the most economically important of all North American upland game birds. All of the species are hunted extensively for sport and are highly …

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Fast Shoreline Erosion Induced By Ship Wakes In A Coastal Lagoon: Field Evidence And Remote Sensing Analysis, Luca Zaggia, Giuliano Lorenzetti, Giorgia Manfe, Gian Marco Scarpa, Emanuela Molinaroli, Kevin E. Parnell, John Rapaglia, Maria Gionta, Tarmo Soomere Oct 2017

Fast Shoreline Erosion Induced By Ship Wakes In A Coastal Lagoon: Field Evidence And Remote Sensing Analysis, Luca Zaggia, Giuliano Lorenzetti, Giorgia Manfe, Gian Marco Scarpa, Emanuela Molinaroli, Kevin E. Parnell, John Rapaglia, Maria Gionta, Tarmo Soomere

Biology Faculty Publications

An investigation based on in-situ surveys combined with remote sensing and GIS analysis revealed fast shoreline retreat on the side of a major waterway, the Malamocco Marghera Channel, in the Lagoon of Venice, Italy. Monthly and long-term regression rates caused by ship wakes in a reclaimed industrial area were considered. The short-term analysis, based on field surveys carried out between April 2014 and January 2015, revealed that the speed of shoreline regression was insignificantly dependent on the distance from the navigation channel, but was not constant through time. Periods of high water levels due to tidal forcing or storm surges, …

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Big Brains Stabilize Populations And Facilitate Colonization Of Variable Habitats In Birds, Trevor S. Fristoe, Andrew N. Iwaniuk, Carlos A. Botero Sep 2017

Big Brains Stabilize Populations And Facilitate Colonization Of Variable Habitats In Birds, Trevor S. Fristoe, Andrew N. Iwaniuk, Carlos A. Botero

Biology Faculty Research

The cognitive buffer hypothesis posits that environmental variability can be a major driver of the evolution of cognition because an enhanced ability to produce flexible behavioural responses facilitates coping with the unexpected. Although comparative evidence supports different aspects of this hypothesis, a direct connection between cognition and the ability to survive a variable and unpredictable environment has yet to be demonstrated. Here, we use complementary demographic and evolutionary analyses to show that among birds, the mechanistic premise of this hypothesis is well supported but the implied direction of causality is not. Specifically, we show that although population dynamics are more …

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Aquaculture Of Coral, Live Rock And Live Sand In Western Australia, Department Of Fisheries Sep 2017

Aquaculture Of Coral, Live Rock And Live Sand In Western Australia, Department Of Fisheries

Fisheries Occasional Publications

Principles and Guidelines Relating to the Assessment of Licences for the Aquaculture of Coral, Live Rock and Live Sand in Western Australia

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Current Status Of American Bullfrog, Lithobates Catesbeianus, Invasion In Uruguay And Exploration Of Chytrid Infection, Gabriel Laufer, Noelia Gobel, Claudio Borteiro, Alvaro Soutullo, Claudio Martinez-Debat, Rafael O. De Sá Aug 2017

Current Status Of American Bullfrog, Lithobates Catesbeianus, Invasion In Uruguay And Exploration Of Chytrid Infection, Gabriel Laufer, Noelia Gobel, Claudio Borteiro, Alvaro Soutullo, Claudio Martinez-Debat, Rafael O. De Sá

Biology Faculty Publications

The American bullfrog Lithobates catesbeianus is an invasive species that can strongly affect native amphibian communities through competition, predation, or introduction of diseases. This frog has invaded multiple areas in South America, for which niche models predict suitable environments across much of the continent. This paper reveals the state of the invasion of this species in Uruguay and its possible relationship with the chytrid pathogenic fungus, Batrachochytrium dendrobatidis. Surveys at invaded sites were conducted from 2007 to 2015, identified two populations undergoing recent range expansion (one of them exponential), two populations that failed to establish, and a new record …

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Synergistic Use Of Remote Sensing And Modeling To Assess An Anomalously High Chlorophyll-A Event During Summer 2015 In The South Central Red Sea, Wenzhao Li, Hesham El-Askary, K. P. Manikandan, Mohamed A. Qurban, Michael J. Garay, Olga V. Kalishnikova Jul 2017

Synergistic Use Of Remote Sensing And Modeling To Assess An Anomalously High Chlorophyll-A Event During Summer 2015 In The South Central Red Sea, Wenzhao Li, Hesham El-Askary, K. P. Manikandan, Mohamed A. Qurban, Michael J. Garay, Olga V. Kalishnikova

Mathematics, Physics, and Computer Science Faculty Articles and Research

An anomalously high chlorophyll-a (Chl-a) event (>2 mg/m3) during June 2015 in the South Central Red Sea (17.5° to 22°N, 37° to 42°E) was observed using Moderate Resolution Imaging Spectroradiometer (MODIS) data from the Terra and Aqua satellite platforms. This differs from the low Chl-a values (<0.5 mg/m3) usually encountered over the same region during summertime. To assess this anomaly and possible causes, we used a wide range of oceanographical and meteorological datasets, including Chl-a concentrations, sea surface temperature (SST), sea surface height (SSH), mixed layer depth (MLD), ocean current velocity and aerosol optical depth (AOD) obtained from different sensors and models. Findings confirmed this anomalous behavior in the spatial domain using Hovmöller data analysis techniques, while a time series analysis addressed monthly and daily variability. Our analysis suggests that a combination of factors controlling nutrient supply contributed to the anomalous phytoplankton growth. These factors include horizontal transfer of upwelling water through eddy circulation and possible mineral fertilization from atmospheric dust deposition. Coral reefs might have provided extra nutrient supply, yet this is out of the scope of our analysis. We thought that dust deposition from a coastal dust jet event in late June, coinciding with the phytoplankton blooms in the area under investigation, might have also contributed as shown by our AOD findings. However, a lag cross correlation showed a two- month lag between strong dust outbreak and the high Chl-a anomaly. The high Chl-a concentration at the edge of the eddy emphasizes the importance of horizontal advection in fertilizing oligotrophic (nutrient poor) Red Sea waters.

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Investigating The Role Of Long Distance Dispersal In The Response Of Stream Fishes To Urbanization, Andrea Davis Jul 2017

Investigating The Role Of Long Distance Dispersal In The Response Of Stream Fishes To Urbanization, Andrea Davis

Master of Science in Integrative Biology Theses

I conducted a 7-month mark-recapture study in two watersheds differing in urban impact in order to assess the role that long distance dispersal plays in the response of tolerant stream fishes to urbanization. Our two stream sites included a heavily impacted urban stream (watershed impervious surface cover ~30%) and a mildly impacted rural stream (watershed impervious surface cover ~6%). Species of interest were marked with 12mm HPT PIT tags and included a specialist, Campostoma oligolepis (n=189 urban site, 200 rural site) and a generalist, Lepomis auritus (n=136 urban site, 182 rural site). Three resampling instances for each site were conducted …

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Negative Density Dependence Mediates Biodiversity–Productivity Relationships Across Scales, Joseph A. Lamanna, R Travis Belote, Laura A. Burkle, Christopher P. Catano, Jonathan A. Myers Jul 2017

Negative Density Dependence Mediates Biodiversity–Productivity Relationships Across Scales, Joseph A. Lamanna, R Travis Belote, Laura A. Burkle, Christopher P. Catano, Jonathan A. Myers

Biology Faculty Research

Regional species diversity generally increases with primary productivity whereas local diversity–productivity relationships are highly variable. This scale-dependence of the biodiversity–productivity relationship highlights the importance of understanding the mechanisms that govern variation in species composition among local communities, which is known as β-diversity. Hypotheses to explain changes in β-diversity with productivity invoke multiple mechanisms operating at local and regional scales, but the relative importance of these mechanisms is unknown. Here we show that changes in the strength of local density-dependent interactions within and among tree species explain changes in β-diversity across a subcontinental-productivity gradient. Stronger conspecific relative to …

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Profiling Bat Activity And Species Presence In Managed Longleaf Pine Landscapes, Margaret Hunt Jun 2017

Profiling Bat Activity And Species Presence In Managed Longleaf Pine Landscapes, Margaret Hunt

Master of Science in Integrative Biology Theses

Restoration of native flora or reintroduction of at-risk fauna includes management practices that while encouraging presence and proliferation of target species, may adversely affect non-focal species. An endemic ecosystem undergoing restoration within the southeastern U.S. is that of the longleaf pine (Pinus palustris). Bats inhabit key ecological niches in forest ecosystems, including the longleaf pine ecosystem, and can be indicators of ecosystem condition. This study investigated the effects of current forest management practices and landscape management history on bat species presence and activity levels within habitat undergoing longleaf pine restoration. We deployed bat detectors in two wildlife management …

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A Global Community Effort To Decipher The Unique Biology Of Annual Killifish, Nibia Berois, Graciela Garcia, Rafael O. De Sá Jun 2017

A Global Community Effort To Decipher The Unique Biology Of Annual Killifish, Nibia Berois, Graciela Garcia, Rafael O. De Sá

Biology Faculty Publications

Over the past 50 years, annual killifishes arose as alternative model organisms for studies of vertebrate biology. The annual fish offers exceptional advantages for studies of genetics, genomics, developmental biology, population dynamics, ecology, biogeography, and evolution. They inhabit extremely variable freshwater environments in Africa and South America, have a short lifespan and a set of unique and fascinating developmental characteristics. Embryos survive within the dry substrate during the dry season, whereas the adult population dies. Thus, the survival of the populations is entirely dependent on the buried embryos that hatch the next rainy season. Although Old and New World species …

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The Population Genetics Of Morro Bay Eelgrass (Zostera Marina), Julia Gardner Harencar Jun 2017

The Population Genetics Of Morro Bay Eelgrass (Zostera Marina), Julia Gardner Harencar

Master's Theses

Seagrass populations are in decline worldwide. Zostera marina (eelgrass), one of California’s native seagrasses, is no exception to this trend. In the last 8 years, Morro Bay, California has lost 95% of its eelgrass. Eelgrass is an ecosystem engineer, providing important ecosystem services such as sediment stabilization, nutrient cycling, and nursery habitats for fish. The failure of recent restoration efforts necessitates a better understanding of the causes of eelgrass decline in this estuary. Previous research on eelgrass in California has demonstrated a link between population genetic diversity and eelgrass bed health, ecosystem functioning, and resilience to disturbance and extreme climatic …

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Characterizing The Impacts Of Contaminants On Fish Embryogenesis And Revealing An Alternate Molecular Mechanism Of Ahr Mediated Cardiac Defects, Corinna Singleman Jun 2017

Characterizing The Impacts Of Contaminants On Fish Embryogenesis And Revealing An Alternate Molecular Mechanism Of Ahr Mediated Cardiac Defects, Corinna Singleman

Dissertations, Theses, and Capstone Projects

There is a long history of damage to natural ecosystems from environmental pollution. Many environmental contaminants are man-made and have been released with abandon over the last 100 years including dioxins, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), and polychlorinated biphenyls (PCBs). These chemicals act on similar cellular processes and cause skin lesions, cancer, learning disabilities and reproductive problems in many vertebrates. There are many studies exploring various aspects of TCDD and PCB exposure on model and wild organisms. Few studies however, have compared effects of PCB mixtures on ecosystems to effects of individual PCBs in the lab. The first aim of this thesis is …

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A Spiny Water Flea Invasion And Effects On The Zooplankton Community In Southern Green Bay, Lake Michigan, Casey Ann Merkle May 2017

A Spiny Water Flea Invasion And Effects On The Zooplankton Community In Southern Green Bay, Lake Michigan, Casey Ann Merkle

Lawrence University Honors Projects

The spiny water flea (Bythotrephes longimanus) is an invertebrate aquatic invasive species (AIS) in the Great Lakes that competes with native fish species for zooplankton, perhaps contributing to a decline of fish populations or changes in zooplankton communities in Lake Michigan. Bythotrephes produce two types of eggs, immediately hatching versus resting eggs which are tolerant to harsh conditions and allow for rapid dispersal. We determined Bythotrephes population density and population dynamics in Green Bay during the summer months of 2015 and 2016. Population dynamics were similar at both sites in Green Bay in each year, with peak population …

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Final Report: Status Of The Arizona Toad (Anaxyrus Microscaphus) In New Mexico, Mason J. Ryan, Jacek Tomasz Giermakowski, Ian M. Latella, Howard L. Snell May 2017

Final Report: Status Of The Arizona Toad (Anaxyrus Microscaphus) In New Mexico, Mason J. Ryan, Jacek Tomasz Giermakowski, Ian M. Latella, Howard L. Snell

Biology Faculty & Staff Publications

This report covers the fourth consecutive year (2013-2016) of research on the population dynamics, ecology, and conservation status of the Arizona Toad (Anaxyrus microscaphus) in New Mexico. The year 2016 represented the rare opportunity to study the effects of El Niño, which typically brings above average precipitation to New Mexico, on the breeding behavior and ecology of the Arizona toad. We expected that the El Niño-driven above average precipitation during the winter of 2015 and spring of 2016 would result in increased detection of toads at breeding sites, especially those sites that were dry in 2013, 2014, and …

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