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Terrestrial and Aquatic Ecology

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Full-Text Articles in Ecology and Evolutionary Biology

A Preliminary Assessment Of Microplastic Pollution In A Local Watershed Of Cincinnati, Ohio, Prior To Reservoir Dredging., Rachel G. Bickett, Gwyneth A. Hagerty, Caroline R. Menosky, Clayton A. Strege Apr 2023

A Preliminary Assessment Of Microplastic Pollution In A Local Watershed Of Cincinnati, Ohio, Prior To Reservoir Dredging., Rachel G. Bickett, Gwyneth A. Hagerty, Caroline R. Menosky, Clayton A. Strege

2023 Midwest Ecology & Evolution Conference

Microplastics, defined as small particles of plastic between 2 and 5 µm, are a pressing environmental concern due to the growing use of plastic products and subsequent disposal. While most microplastic research has focused on marine systems, a growing concern exists on the presence of microplastics in freshwater systems and additional impacts to humans and wildlife. The main objective of this preliminary study was to assess the prevalence of microplastics in water surrounding a dammed reservoir. These results will provide baseline data to assess the role of dam dredging on microplastics. Samples were taken from Sharon Woods Park, Cincinnati, Ohio, …


Effect Of Temperature Variation On Endurance Swimming Capacity Of Juvenile White Sturgeon (Acipenser Transmontanus), Alex M. Stolberg Apr 2023

Effect Of Temperature Variation On Endurance Swimming Capacity Of Juvenile White Sturgeon (Acipenser Transmontanus), Alex M. Stolberg

2023 Midwest Ecology & Evolution Conference

White sturgeon (Acipenser transmontanus), a species within one of the most globally threatened taxa, are highly susceptible to changes in their environments due to unique life history traits. Specifically, juvenile white sturgeon are impacted by altered watershed dynamics caused by water diversion structures such as dams, weirs, irrigation ditches, or levees. One location of great concern is the Sacramento-San Joaquin (S-SJ) watershed where decades of water diversion has brought on changes to the temperature, flow, and management of the area. This study looks to primarily identify the impact of water temperature on the endurance swimming capacity of juvenile white sturgeon, …


Host Size Reduction In Response To Parasitic Infection Fuels Trophic Cascades, Lauren Albert Apr 2023

Host Size Reduction In Response To Parasitic Infection Fuels Trophic Cascades, Lauren Albert

2023 Midwest Ecology & Evolution Conference

Outbreaks of disease epidemics continue to erupt in host populations. Within these populations, parasites drive top-down effects. For example, when parasites kill their hosts, they can indirectly increase the hosts’ resource density, causing trophic cascades. This phenomena arises in a diversity of parasite-host-resource systems; however, the mechanisms of parasite-driven trophic cascades remain less clear. A straightforward density-mediated mechanism occurs when parasites increase host mortality, depressing host density. Alternatively, host traits such as body size could be affected, depressing host resource regulation. To disentangle connections between parasites and trophic cascades, we must measure mechanisms operating at both the population (density) and …


Analyzing Decomposition In A Temperate Lotic System, Trevor J. Rallo Apr 2023

Analyzing Decomposition In A Temperate Lotic System, Trevor J. Rallo

2023 Midwest Ecology & Evolution Conference

Decomposition of allochthonous material (e.g., leaves or woody debris) is an important process in stream ecosystems. Breakdown of this allochthonous matter is dependent on multiple factors, such as species identity or the habitat type (e.g. riffle vs pool). Decomposition rate has received limited attention as a potential metric of stream health, which could be useful for conservation and citizen science groups. In this study, we quantified microbe density and macroinvertebrate diversity, and related these variables back to the decomposer taxa, habitat type and stream health value (quantified as Q-value). Leaf litter bags that varied in mesh size (2.0 and 0.5 …


Pre-Dredging Assessment Of Aquatic Macroinvertebrates From Sharon Lake And Creek, Cincinnati, Ohio, Paige M. Loboschefski, Addyson M. Thomas, Emma J. Weiss Apr 2023

Pre-Dredging Assessment Of Aquatic Macroinvertebrates From Sharon Lake And Creek, Cincinnati, Ohio, Paige M. Loboschefski, Addyson M. Thomas, Emma J. Weiss

2023 Midwest Ecology & Evolution Conference

Dams can serve a multitude of purposes for humans including water storage and flood control. However, dams can also have negative cascading impacts on the surrounding ecosystem. One impact is sedimentation, where reduced water flow can increase the accumulation of benthic sediment. Nutrients can also accumulate leading to eutrophication, affecting organismal and ecosystem health. In order to improve water and ecosystem quality, dredging can occur to remove benthic sediments. The main objective of this study was to characterize the macroinvertebrate community above and below a dam prior to substrate dredging. This study was conducted in Sharon Lake and Creek near …


Geographic Analysis Of Sex Chromosome Polymorphism In The Virginian Wild Strawberry, Trezalka A. Budinsky Apr 2023

Geographic Analysis Of Sex Chromosome Polymorphism In The Virginian Wild Strawberry, Trezalka A. Budinsky

2023 Midwest Ecology & Evolution Conference

The evolution of sex chromosomes is a ubiquitous and essential diversifying mechanism in eukaryotes. Yet early stages of sex-chromosome differentiation are poorly understood. The subdioecious octoploid, Fragaria virginiana, provides a rare opportunity to study the beginnings of sex chromosome evolution due to its young, polymorphic ZW sex system. Females are ZW and males/hermaphrodites are ZZ. F. virginiana has a small sex-determining region (SDR) located on the female W chromosome that has undergone three transposition events between the strawberry's four subgenomes, resulting in three SDR haplotypes: alpha (the result of a first transposition and closest to a pre-sex chromosome ancestral …


Phosphours Trasnport In Soil: Locating And Identifying A Limiting Element, Jeremy Giannone Apr 2023

Phosphours Trasnport In Soil: Locating And Identifying A Limiting Element, Jeremy Giannone

2023 Midwest Ecology & Evolution Conference

The phosphorus (P) cycle is not well understood. While carbon (C) and nitrogen (N) have gas phases, P does not. Phosphorus runoff in waterways and its shortage are both understood since their causes are due to agricultural demands. Fertilizers increase the rate of phosphorus in the soil leading to greater runoff which then accumulates in the surrounding bodies of water.1 From an economic perspective the phosphorus availability and food prices have a direct correlation. The instability of phosphate prices may have direct causation to the instability of the food and agriculture markets.2In order to deal with these …


Rapid Assesment Of Aquatic Insect Diversity And Abundance Used To Evaluate The Quality Of Stream Restoration, Kaleb Stephen Kindoll Apr 2023

Rapid Assesment Of Aquatic Insect Diversity And Abundance Used To Evaluate The Quality Of Stream Restoration, Kaleb Stephen Kindoll

2023 Midwest Ecology & Evolution Conference

Stream and wetland restoration activities seek to improve the function of aquatic ecosystems. Measurement of the diversity and abundance of aquatic insects are commonly used to evaluate the success of restoration efforts, but these measurements are often very time consuming. In this study, we attempt to construct an efficient method that can be used to rapidly assess the diversity and abundance of aquatic insects as a measure of the quality of stream restoration. We suspended uniform sized pieces of cardboard paper coated with adhesive to trap insects in three different environments: one restored and two unrestored streams with similar characteristics. …


Aquatic Vegetation Seed Bank Status Of Kentucky Lake, Emily A. Freeman Apr 2023

Aquatic Vegetation Seed Bank Status Of Kentucky Lake, Emily A. Freeman

2023 Midwest Ecology & Evolution Conference

Aquatic vegetation is an important biotic component of reservoir ecosystems. Vegetation reduces erosion by acting as a barrier against current and waves from the lake. Aquatic vegetation also helps to oxygenate the water, stabilize nutrients like carbon, nitrogen, and phosphorus, and provides structure for aquatic vertebrates. The absence of vegetation in Kentucky Lake has been influenced by a fluctuating water table (due to winter lake drawdowns), invasive carp, and the use of herbicides for grass management. The objective of this study is to determine the state of the remaining seedbank within nautical mile markers 45 and 52. By using long-term …


An Assessment Of Aquatic Macroinvertebrate Structure And Function Within The Mill Creek Watershed; Cincinnati, Ohio, Erin Linko Apr 2023

An Assessment Of Aquatic Macroinvertebrate Structure And Function Within The Mill Creek Watershed; Cincinnati, Ohio, Erin Linko

2023 Midwest Ecology & Evolution Conference

The Mill Creek Watershed is an urbanized network of streams that drains through the city of Cincinnati, Ohio. This watershed has had a long history of habitat destruction and pollution due to a variety of anthropogenic factors, namely Cincinnati’s combined sewage overflow (CSO) sanitation system. Through an ongoing biomonitoring project at Xavier University, nine sites along the mainstem Mill Creek and three of its tributaries have been studied since 2014. Through habitat assessments, fecal coliform testing, and aquatic macroinvertebrate sampling, the ecological health of this watershed can be tracked over time. The main objective of this research project was to …


Examining The Reproductive Ecology Of Terrapene Ornata In Western Nebraska, Katie Brighton, Keetan Munsell Apr 2023

Examining The Reproductive Ecology Of Terrapene Ornata In Western Nebraska, Katie Brighton, Keetan Munsell

2023 Midwest Ecology & Evolution Conference

Understanding the reproductive ecology of any species is vital for determining intraspecific variation in individual fitness, modeling population growth or persistence potential, and developing effective conservation strategies. The reproductive ecology of many species has been extensively studied (particularly in mammals); however, other taxonomic groups including many ectotherms has not been well documented. One such ectotherm is the ornate box turtle (Terrapene ornata), which, to our knowledge, has never had its reproductive ecology extensively examined, especially in the field. In this study, we examined the reproductive ecology of ornate box turtles over a six-week period in a mixed shortgrass prairie in …


Where The Wild Mushrooms Are: Species And Secondary Metabolite Diversity In Fungal Species On The Saint Mary’S College Campus, Lex K. Gilman Apr 2023

Where The Wild Mushrooms Are: Species And Secondary Metabolite Diversity In Fungal Species On The Saint Mary’S College Campus, Lex K. Gilman

2023 Midwest Ecology & Evolution Conference

Secondary metabolites in fungi have three main ecological functions: protection against predation, communication with other mushrooms, and assistance in pathogenic interactions. These compounds have also led to the common use of mushrooms as food and in traditional Chinese or other medicinal applications. However, there are currently few good resources for identifying mushroom species in North-Central Indiana. In addition, limited research exists on secondary metabolites in mushrooms. The objective of this research was to create a preliminary database of mushroom species at Saint Mary’s College and conduct preliminary research on the secondary metabolites of these local species. Fungal specimens were identified …


Is Lineage C A Distinct Species?, Shiza Khan Apr 2023

Is Lineage C A Distinct Species?, Shiza Khan

Honors Theses

No abstract provided.


Groundwater-Stream Connections Shape The Spatial Pattern And Rates Of Aquatic Metabolism, Anna Lupon, Lluís Gomez-Gener, Megan Fork, Hjalmar Laudon, Eugènia Martí, William Lidberg, Ryan A. Sponseller Apr 2023

Groundwater-Stream Connections Shape The Spatial Pattern And Rates Of Aquatic Metabolism, Anna Lupon, Lluís Gomez-Gener, Megan Fork, Hjalmar Laudon, Eugènia Martí, William Lidberg, Ryan A. Sponseller

Biology Faculty Publications

A longstanding challenge in stream ecology is to understand how landscape configuration organizes spatial patterns of ecosystem function via lateral groundwater connections. We combined laboratory bioassays and field additions of a metabolic tracer (resazurin) to test how groundwater-stream confluences, or "discrete riparian inflow points " (DRIPs), regulate heterotrophic microbial activity along a boreal stream. We hypothesized that DRIPs shape spatial patterns and rates of aquatic heterotrophic microbial activity by supplying labile dissolved organic matter (DOM) to streams. Laboratory bioassays showed that the potential influence of DRIPs on heterotrophic activity varied spatially and temporally, and was related to their DOM content …


Understory Epiphyte Hydrology: Analyzing Water Storage Capacity Of Epiphytes Along An Elevational Gradient In Western Ecuadorian Cloud Forest, Angelina Dodge Apr 2023

Understory Epiphyte Hydrology: Analyzing Water Storage Capacity Of Epiphytes Along An Elevational Gradient In Western Ecuadorian Cloud Forest, Angelina Dodge

Independent Study Project (ISP) Collection

Epiphytes are defined as plants that grow on a host, often another plant, and acquire their nutrients and water from the atmosphere. As such is true, epiphyte composition is largely dependent upon atmospheric and thus climactic conditions. Due to high levels of atmospheric water availability that results from the frequent presence of mist, clouds, and high humidity, epiphytic plants grow and thus store water within the above ground region of the Andean cloud forest at levels higher than in any other ecosystem found in Ecuador. This study was done in hopes of revealing any trends of epiphytic water storage capacity …


Highly Pathogenic Avian Influenza A(H5n1) Virus Outbreak In New England Seals, United States, Wendy Puryear, Kaitlin Sawatzki, Nichola Hill, Alexa Foss, Jonathon J. Stone, Lynda Doughty, Dominique Walk, Katie Gilbert, Maureen Murray, Elena Cox, Priya Patel, Zak Mertz, Stephanie Ellis, Jennifer Taylor, Deborah Fauquier, Ainsley Smith, Robert A. Digiovanni, Adriana Van De Guchte, Ana Silvia Gonzalez-Reiche, Zain Khalil, Harm Van Bakel, Mia K. Torchetti, Kristina Lantz, Julianna B. Lenoch, Jonathan Runstadler Apr 2023

Highly Pathogenic Avian Influenza A(H5n1) Virus Outbreak In New England Seals, United States, Wendy Puryear, Kaitlin Sawatzki, Nichola Hill, Alexa Foss, Jonathon J. Stone, Lynda Doughty, Dominique Walk, Katie Gilbert, Maureen Murray, Elena Cox, Priya Patel, Zak Mertz, Stephanie Ellis, Jennifer Taylor, Deborah Fauquier, Ainsley Smith, Robert A. Digiovanni, Adriana Van De Guchte, Ana Silvia Gonzalez-Reiche, Zain Khalil, Harm Van Bakel, Mia K. Torchetti, Kristina Lantz, Julianna B. Lenoch, Jonathan Runstadler

United States Department of Agriculture Wildlife Services: Staff Publications

We report the spillover of highly pathogenic avian influenza A(H5N1) into marine mammals in the northeastern United States, coincident with H5N1 in sympatric wild birds. Our data indicate monitoring both wild coastal birds and marine mammals will be critical to determine pandemic potential of influenza A viruses.


A Multiscale Linkage Between Riverscape And Fish Community Coevolution, Loren W. Stearman Mar 2023

A Multiscale Linkage Between Riverscape And Fish Community Coevolution, Loren W. Stearman

Dissertations

Sediment dynamics are foundational to stream and watershed morphology. Yet aquatic ecologists have relied on an oversimplified model of sediment dynamics characterizing sediments as agents of stream bed burial, and which fails to describe many types of aquatic habitat evolution. In this dissertation I employ both fluvial geomorphic and ecological frameworks to gain a deeper understanding of how sediment dynamics shape stream morphology and fish community evolution at multiple scales. Using a paired historic and contemporary approach, I analyzed geomorphic evolution and fish community change in the Bayou Pierre, Mississippi, from the 1980s to recent. Patterns of erosion due to …


Cell Volume As A Determinant Of Virus-Mediated Population Growth In Ciliates, Jace Miller, John Paul Delong Phd Mar 2023

Cell Volume As A Determinant Of Virus-Mediated Population Growth In Ciliates, Jace Miller, John Paul Delong Phd

Honors Program: Senior Projects (Public)

Many protists and other small aquatic organisms consume virus particles, a behavior known as virovory. Some species of protists, such as the ciliate Halteria grandinella, can grow and divide using viruses as their sole food source. Other ciliate species have previously been shown to consume large quantities of viral particles, but it is unclear if they are able to support population growth with viruses alone. Because large ciliates have a higher energy demand, we hypothesize that they will be unable to support population growth on a virus-only diet. We fed nine ciliate species a diet of chloroviruses and found …


Assessment Of Largemouth Bass (Micropterus Salmoides) Condition Using Liver Histopathology, Health Parameters And Water Quality Of The Central Chattahoochee River Watershed, Kari Carmack Goodwin Mar 2023

Assessment Of Largemouth Bass (Micropterus Salmoides) Condition Using Liver Histopathology, Health Parameters And Water Quality Of The Central Chattahoochee River Watershed, Kari Carmack Goodwin

Theses and Dissertations

The health of Largemouth bass from west-central Georgia was assessed using liver histopathology and the degree of tissue change index (DTC), hepatosomatic indices (HSI), relative weight, condition factors, and intersex. These health parameters as well as water chemistry data were compared across four bodies of water, three within the Chattahoochee watershed, and one pseudo-control located in the Flint watershed. Fish from Lake Oliver, Lake Harding, and West Point Lake had severely impacted liver health compared to Warm Springs National Fish Hatchery, with DTC rankings over 100 for the three lakes within the Chattahoochee watershed, demonstrating severely damaged livers. There was …


Center For Grassland Studies, March 2023 Mar 2023

Center For Grassland Studies, March 2023

Center for Grassland Studies: Newsletters

Contents

New Assistant Director for The Center for Grassland Studies, David Wedin

Center for Grassland Studies Policy Advisory Committee

Director's Column by Jerry Volesky (Interim Director)

Congratulations December 2022 Graduates

New Grazing Lands Ecologist for Grassland Studies, Nic McMillan

New Administrative Associate for Grassland Studies, Ashley Branting

Apply Now for CGS Scholarships and Assistantship, https://grassland.unl.edu/grassland-systems/grazing-livestock-scholarships

New Guidelines for Reducing Eastern Redcedar in Grasslands by Dillon Fogarty

Year One Barta Brothers Ranch Collaborative Adaptive Management Update by Craig Allen

Nebraska Grazing Conference, August 8-9, 2023 by Daren Redfearn

Forty Years Reflection on Grassland Fire Weather by David Wedin

Nebraska Youth Range …


Lichens Of Ultramafic Rocks: A Multidisciplinary Approach To Understanding The Ecology Of An Understudied Organism In A Well-Studied System, Michael Mulroy Mar 2023

Lichens Of Ultramafic Rocks: A Multidisciplinary Approach To Understanding The Ecology Of An Understudied Organism In A Well-Studied System, Michael Mulroy

Master's Theses

Lichens are among the most prominent and successful life forms of metal-rich habitats, including ultramafic rocks and soils; however, research on lichens of ultramafic habitats is limited, especially on the North American continent. A review of the published literature on lichens of ultramafic substrates in North America yielded a total of 437 lichen species reported from ultramafic rocks and soils. Lichen assemblages of ultramafic substrates vary in composition and are dominated by acidophytic (low pH preferring) taxa with a minor, but consistent, basiphytic (high pH preferring) component. Species lists from ultramafic habitats in different geographic regions varied widely, suggesting that …


Remembering Paul Johnsgard, Linda R, Brown, Josef Kren Mar 2023

Remembering Paul Johnsgard, Linda R, Brown, Josef Kren

Zea E-Books Collection

Paul A. Johnsgard (1931–2021) was a friend of many, an artist, prolific author, teacher, and humble admirer of all living creatures. It was impossible to find someone at Nebraska Audubon Society or Nebraska Ornithologists’ Union meetings who did not know Paul Johnsgard. His more than 100 published books made him known not just in a community of ornithologists, birdwatchers, and bird lovers in the United States but also abroad. He was a world-renowned ornithologist and naturalist who remained deeply embedded in his local culture and its prairie environment.

We invited about 75 people to write a short memory of Paul. …


Prairie Dogs, Gary Witmer, Jon Grant, Kendra Cross Mar 2023

Prairie Dogs, Gary Witmer, Jon Grant, Kendra Cross

Wildlife Damage Management Technical Series

Prairie dogs (Cynomys spp.) occur throughout the prairie states of middle North America from Mexico northward into Canada. They occupy a variety of habitats from prairies to high mountain valleys and sage brush-dominated deserts. The most common species is the black-tailed prairie dog (Cynomys ludovicianus; Figure 1). Prairie dogs are considered a “keystone species.” They provide habitat for many other native, grassland species. Prairie dogs live in colonies or “towns” that can span hundreds to thousands of acres. Depending on the species, their presence is evident by their burrow system. Despite the many ecosystem benefits prairie dogs provide by modifying …


Elevated Estuary Water Temperature Drives Fish Gut Dysbiosis And Increased Loads Of Pathogenic Vibrionaceae, Alessandra L. Suzzi, Michael Stat, Troy F. Gaston, Nachshon Siboni, Nathan L. R. Williams, Justin R. Seymour, Megan J. Huggett Feb 2023

Elevated Estuary Water Temperature Drives Fish Gut Dysbiosis And Increased Loads Of Pathogenic Vibrionaceae, Alessandra L. Suzzi, Michael Stat, Troy F. Gaston, Nachshon Siboni, Nathan L. R. Williams, Justin R. Seymour, Megan J. Huggett

Research outputs 2022 to 2026

Marine water temperatures are increasing globally, with eastern Australian estuaries warming faster than predicted. There is growing evidence that this rapid warming of coastal waters is increasing the abundance and virulence of pathogenic members of the Vibrionaceae, posing a significant health risk to both humans and aquatic organisms. Fish disease, notably outbreaks of emerging pathogens in response to environmental perturbations such as heatwaves, have been recognised in aquaculture settings. Considerably less is known about how rising sea surface temperatures will impact the microbiology of wild fish populations, particularly those within estuarine systems that are more vulnerable to warming. We used …


Blanding’S Turtle (Emydoidea Blandingii): Species Conservation Assessment, Melissa J. Panella, Colleen Rothe-Groleau Feb 2023

Blanding’S Turtle (Emydoidea Blandingii): Species Conservation Assessment, Melissa J. Panella, Colleen Rothe-Groleau

Nebraska Game and Parks Commission: Publications

The primary goal in development of at-risk species conservation assessments is to compile biological and ecological information that may assist conservation practitioners in making decisions regarding the conservation of species of interest. The Nebraska Natural Legacy Project recognizes the Blanding’s turtle (Emydoidea blandingii) as a Tier 1 at-risk species. Some general management recommendations are made here regarding Blanding’s turtles; however, conservation practitioners will need to use professional judgment to make specific management decisions based on objectives, location, and a multitude of variables. This resource was designed to share available knowledge of this at-risk turtle that will aid in the decision-making …


Refining The Moose Serum Progesterone Threshold To Diagnose Pregnancy, Madeline Struck, William J. Severud, Yvette M. Chenaux-Ibrahim, Edmund J. Isaac, Janine L. Brown, Seth A. Moore, Tiffany M. Wolf Feb 2023

Refining The Moose Serum Progesterone Threshold To Diagnose Pregnancy, Madeline Struck, William J. Severud, Yvette M. Chenaux-Ibrahim, Edmund J. Isaac, Janine L. Brown, Seth A. Moore, Tiffany M. Wolf

Natural Resource Management Faculty Publications

Pregnancy determination is necessary for sound wildlife management and understanding population dynamics. Pregnancy rates are sensitive to environmental and physiological factors and may indicate the overall trajectory of a population. Pregnancy can be assessed through direct methods (rectal palpation, sonography) or indicated using hormonal assays (serum progesterone or pregnancy-specific protein B, fecal progestogen metabolites). A commonly used threshold of 2 ng/ml of progesterone in serum has been used by moose biologists to indicate pregnancy but has not been rigorously investigated. To refine this threshold, we examined the relationship between progesterone concentrations in serum samples and pregnancy in 87 moose ( …


An Evaluation Of Avian Influenza Virus Whole-Genome Sequencing Approaches Using Nanopore Technology, Hon S. Ip, Sarah Uhm, Mary Lea Killian, Mia K. Torchetti Feb 2023

An Evaluation Of Avian Influenza Virus Whole-Genome Sequencing Approaches Using Nanopore Technology, Hon S. Ip, Sarah Uhm, Mary Lea Killian, Mia K. Torchetti

United States Department of Agriculture Wildlife Services: Staff Publications

As exemplified by the global response to the SARS-CoV-2 pandemic, whole-genome sequencing played an important role in monitoring the evolution of novel viral variants and provided guidance on potential antiviral treatments. The recent rapid and extensive introduction and spread of highly pathogenic avian influenza virus in Europe, North America, and elsewhere raises the need for similarly rapid sequencing to aid in appropriate response and mitigation activities. To facilitate this objective, we investigate a next-generation sequencing platform that uses a portable nanopore sequencing device to generate and present data in real time. This platform offers the potential to extend in-house sequencing …


American Eel (Anguilla Rostrata) And Other Fishes As Surveyed By Environmental Dna In The Bronx River And Hudson River Watershed, Sam C. Chin Feb 2023

American Eel (Anguilla Rostrata) And Other Fishes As Surveyed By Environmental Dna In The Bronx River And Hudson River Watershed, Sam C. Chin

Dissertations, Theses, and Capstone Projects

Mounting an effective response to the threats faced by freshwater fish may require expansions to aquatic biomonitoring in excess of what is feasible using the capture-based survey techniques currently relied upon by natural resource managers. Methods for analyzing environmental DNA (eDNA) are emerging as a minimally invasive and cost-effective approach for surveying fish and other organisms. By detecting taxon-specific DNA sequences recovered from environmental samples (e.g. water, sediment), eDNA methods are able to infer species presence from samples that can be collected rapidly with simple equipment. In many cases, eDNA detection rates of fish species have been shown to meet …


A Statistical Analysis Of The Change In Age Distribution Of Spawning Hatchery Salmon, Rachel Macaulay, Emily Barrett, Grace Penunuri, Eli E. Goldwyn Jan 2023

A Statistical Analysis Of The Change In Age Distribution Of Spawning Hatchery Salmon, Rachel Macaulay, Emily Barrett, Grace Penunuri, Eli E. Goldwyn

Spora: A Journal of Biomathematics

Declines in salmon sizes have been reported primarily as a result of younger maturation rates. This change in age distribution poses serious threats to salmon-dependent peoples and ecological systems. We perform a statistical analysis to examine the change in age structure of spawning Alaskan chum salmon Oncorhynchus keta and Chinook salmon O. tshawytscha using 30 years of hatchery data. To highlight the impacts of this change, we investigate the average number of fry/smolt that each age of spawning chum/Chinook salmon produce. Our findings demonstrate an increase in younger hatchery salmon populations returning to spawn, and fewer amounts of fry produced …


Landscape And Site Factors Drive Invasive Phragmites Management And Native Plant Recovery Across Chesapeake Bay Wetlands, Christine B. Rohal, Eric L. G. Hazelton, Eliza K. Mcfarland, Rebekah Downard, Melissa K. Mccormick, Dennis F. Whigham, Karin M. Kettenring Jan 2023

Landscape And Site Factors Drive Invasive Phragmites Management And Native Plant Recovery Across Chesapeake Bay Wetlands, Christine B. Rohal, Eric L. G. Hazelton, Eliza K. Mcfarland, Rebekah Downard, Melissa K. Mccormick, Dennis F. Whigham, Karin M. Kettenring

Watershed Sciences Student Research

Successful invasive plant management—where invaders are sufficiently reduced and diverse native plant communities recover—remains an elusive goal for land managers. The site- and landscape-scale drivers of variable management outcomes and vegetation recovery are poorly understood due to a lack of rigorous experiments that characterize longer term vegetation trends across contexts. We present the results of a five-year experiment across eight subestuaries of Chesapeake Bay, representing a gradient of watersheds with differing dominant land-use types and anthropogenic impacts, to evaluate invasive and native plant response to herbicide management. The focal invader, Phragmites australis (common reed), is one of the most aggressive …