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2023

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Biorecovery Of Rare Earth Elements From Hard Rock, Extraction And Analysis, Moustapha Kebe Dec 2023

Biorecovery Of Rare Earth Elements From Hard Rock, Extraction And Analysis, Moustapha Kebe

Engineering

The advancement toward green energy, the development of precise weaponry, and the conquest of space have made the consumption of rare earth elements and critical elements supersede their production. Rare earth elements are vital and critical for modern technology. Rare earth elements consist of Scandium, Yttrium, and the fifteen elements in the Lanthanide group. These elements are mainly categorized into two types based on their atomic number: Light Rare Earth Elements (LREE) and Heavy Rare Earth Elements (HREE). The conventional methods of extracting economic rare earth elements are widely known, and these methods are found in abundance. However, considering the …

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What's Going On In There? Canadian Government Policy Labs And Public Value Management, Adam Wellstead, Nora Ottenhof, Bryan Evans, Anat Gofen Dec 2023

What's Going On In There? Canadian Government Policy Labs And Public Value Management, Adam Wellstead, Nora Ottenhof, Bryan Evans, Anat Gofen

Michigan Tech Publications

Government-based policy labs have established themselves across the Canadian policy landscape. This article argues these labs contribute to public value management. We begin by reviewing the public value management literature, followed by Canadian contributions to the policy lab literature. Then, our inventory of 35 current Canadian government-based policy labs is descriptively analyzed, including trends in spatial concentration, the tools and methods employed, their focus areas, the number of years in existence, and their primary role in the policy process. We randomly selected nine of these labs, provide more details of their activities, and present a preliminary public value management typology …

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Volcanic Gas Quantification Under Suboptimal Conditions, D. Skye Kushner Dec 2023

Volcanic Gas Quantification Under Suboptimal Conditions, D. Skye Kushner

Geosciences

Volcanic gas emissions are challenging to quantify. Achieving high confidence in gas composition, column concentrations, and emission rates acquired using remote sensing techniques is thought to require optimal atmospheric conditions. These conditions are often not met, creating a reluctance to preform measurements under non-ideal atmospheric conditions with inherent uncertainty about how useful those measurements may be. In the case of volcanic eruptions, the hazardous nature of the volcanic plume creates an environment where it is often not safe to collect measurements. This dissertation presents three projects which aim to constrain the quantity of two specific volcanic gases, mercury (Hg) and …

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Icy Insights: Decrypting The Depths With Novel Stochastic Techniques To Model And Mitigate Arctic Under-Ice Oil Spills, Kelsey A. Frazier Dec 2023

Icy Insights: Decrypting The Depths With Novel Stochastic Techniques To Model And Mitigate Arctic Under-Ice Oil Spills, Kelsey A. Frazier

Engineering

The retreat and thinning of Arctic sea ice, driven by climate change, have increased the potential for maritime navigation in the region, thereby heightening concerns about the environmental impacts of potential oil spills in the Arctic. This dissertation, with a focus on the Beaufort and Chukchi Seas, seeks to develop a remote predictive method for assessing the subsurface features of Arctic sea ice, thereby facilitating rapid responses to Arctic oil spills without depending on time-consuming in situ measurements. The first paper of this dissertation addresses the need for oil spill modelers to understand oil movement along the subsurface of sea …

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Dynamics Of The Earth's Thermosphere Across A Range Of Spatial And Temporal Scales, Rajan Itani Dec 2023

Dynamics Of The Earth's Thermosphere Across A Range Of Spatial And Temporal Scales, Rajan Itani

Physics

This dissertation presents an investigation of aspects of the dynamics of Earth's thermosphere that do not harmonize with the current understanding. Three distinct thermospheric phenomena that correspond to different spatial and temporal scales were examined using Fabry-Perot interferometer measurements of wind and temperature to investigate aspects of thermospheric dynamics. Earth's thermosphere has very high kinematic viscosity and is highly convectively stable. Theory and physics-based models suggest that structures in the horizontal wind on small spatial scales (∼500 km or less) are unlikely to occur in the upper thermosphere. By contrast, a large-scale, persistent, strong wind flow that transports air parcels …

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The Role Of Apex Predators, Habitat, And Seascape Complexity On Nearshore Fish Assemblages In Southeast, Alaska, Lia K. Domke Dec 2023

The Role Of Apex Predators, Habitat, And Seascape Complexity On Nearshore Fish Assemblages In Southeast, Alaska, Lia K. Domke

Fisheries

Nearshore marine ecosystems contain dynamic and complex submerged vegetated habitats that offer shelter and prey for juvenile, migratory, and residential species, including many commercial, subsistence, and recreationally important species. The efficacy of the nursery role, shelter, and source of prey of the nearshore is influenced by various abiotic and biotic forces and in this dissertation, we examine the influence of submerged vegetation type, presence of apex predators, and the seascape context on patterns of nearshore fish assemblages in southern Southeast Alaska. We found species-specific responses by juvenile salmon in the nearshore, with seasonality overwhelmingly driving juvenile salmon abundance in eelgrass …

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Uncovering Patterns And Mechanisms Of Paralytic Shellfish Toxicity In Alaska's Geoduck Clam Fishery, Courtney E. Hart Dec 2023

Uncovering Patterns And Mechanisms Of Paralytic Shellfish Toxicity In Alaska's Geoduck Clam Fishery, Courtney E. Hart

Fisheries

This dissertation explores the patterns and mechanisms of paralytic shellfish toxicity in commercially harvested geoduck clams caused by the toxin-producing dinoflagellate Alexandrium catenella in Southeast Alaska. Alaska's commercial fishery for geoduck clams (Panopea generosa) is a small but lucrative fishery, with annual ex-vessel values averaging US $3.9 million (2010-2022). In recent years, the presence of paralytic shellfish toxins (PSTs) in clam tissue resulted in declines in fishery openings and harvest. PSTs can bioaccumulate in the tissues of filter feeders when A. catenella blooms in the spring and summer seasons. However, high levels of toxicity in geoduck clams occur sporadically during …

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Model-Based Estimation Of Juvenile Salmon Spatial Ecology In The Eastern Bering Sea, Alaska, Lilian Hart Dec 2023

Model-Based Estimation Of Juvenile Salmon Spatial Ecology In The Eastern Bering Sea, Alaska, Lilian Hart

Fisheries

Quantitative descriptions of juvenile salmon spatial ecology during the marine phase of their lifecycle are needed to help direct conservation efforts and uncover latent relationships between juvenile salmon and their environment. The NOAA Fisheries Essential Fish Habitat (EFH) program contributes to the conservation of species in the marine waters off of the coast of Alaska by identifying areas of particular importance to reproduction and growth. Salmon EFH definitions have not yet been updated using the species distribution modeling approach taken most recently in defining Alaska groundfish and crab EFH. Current EFH definitions for Alaskan salmon are geographically broad, do not …

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When Beavers Get Burned, Do Fish Get Fried? The Role Of Beavers To Mediate Wildfire Effects On Arctic Grayling In Boreal Alaska, William T. Samuel Dec 2023

When Beavers Get Burned, Do Fish Get Fried? The Role Of Beavers To Mediate Wildfire Effects On Arctic Grayling In Boreal Alaska, William T. Samuel

Fisheries

Wildfire is a dominant natural disturbance process throughout boreal North America and fires are increasing in size, frequency, and severity. However, little is known about how wildfire affects boreal fish populations and aquatic habitat despite the substantial impacts of fire on ecosystem processes, and even less is known about how fire effects are mediated by species interactions. For example, North American Beavers (Castor canadensis) are affected by and can influence wildfire dynamics, and their engineering has complex effects on aquatic habitats. North American Beavers therefore have the potential to mediate wildfire effects on aquatic ecosystems and fish populations. Here I …

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Estimating Relative Indices Of Groundfish Abundance From Multiple Fishery-Independent Data Sources: A Comparison Of Intercalibrating Model-Based Abundance Estimators, Tristan Noble Sebens Dec 2023

Estimating Relative Indices Of Groundfish Abundance From Multiple Fishery-Independent Data Sources: A Comparison Of Intercalibrating Model-Based Abundance Estimators, Tristan Noble Sebens

Fisheries

Stock assessments are critical tools for sustainable fisheries management, and abundance indices estimated from fishery-independent data represent a crucial data source for these assessments. However, financial constraints on these surveys limit the number of samples taken per year, and/or the frequency with which regions are sampled. Additionally, it remains challenging for any individual survey to sample the entire domain of a stock due to contact-selectivity of the sampling gear and the accessibility of specific habitats to specific gear types. Further, the cost of operating fishery-independent surveys can result in surveys conducted on biennial or triennial schedules, resulting in temporal gaps …

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Relative Abundance And Movement Ecology Of Tiger Sharks Galeocerdo Cuvier In The Waters Surrounding Bimini, The Bahamas, Matthew J. Smukall Dec 2023

Relative Abundance And Movement Ecology Of Tiger Sharks Galeocerdo Cuvier In The Waters Surrounding Bimini, The Bahamas, Matthew J. Smukall

Fisheries

Shark populations are under increased anthropogenic pressures around the world. Large-bodied shark species are upper trophic level predators, and therefore there is concern that declining numbers of sharks may have significant implications for ecosystems. In response to these conservation concerns there has been increased focus on the implementation of regulations, fishery management plans, national plans of action, and marine management zones in some nations. However, large sharks are often highly mobile and can move readily across jurisdictional boundaries. Therefore, there is a need to monitor long-term relative abundances within regions and simultaneously examine the duration to which species remain in …

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The Third Week Of Advent: A Visio Divina Devotion, Ann Zlotnik Dec 2023

The Third Week Of Advent: A Visio Divina Devotion, Ann Zlotnik

Marian Library Blog Archive

Immerse yourself in the joyful details of John August Swanson's Nativity art while following a guided reflection.

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The Third Week Of Advent: A Visio Divina Devotion, Ann Zlotnik Dec 2023

The Third Week Of Advent: A Visio Divina Devotion, Ann Zlotnik

Marian Library Blog Archive

Immerse yourself in the joyful details of John August Swanson’s Nativity art while following a guided reflection.

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Emotional Labor In Front-Facing Jobs In University Settings, Khushboo Jain Dec 2023

Emotional Labor In Front-Facing Jobs In University Settings, Khushboo Jain

Student Theses and Dissertations

This research aims to investigate how employees in front-facing/public-oriented positions engage in and experience the effects of emotional labor. Emotional labor is the unpaid, frequently unseen work a person must perform to manage their emotions for other people (Resnick, 2021). This kind of labor can manifest in multiple settings such as the workplace and interpersonal relationships. Emotional labor is often a problem in organizations because there is more focus on how the employee is representing them in customer interactions than the employee’s well-being. During face-to-face or voice-to-voice interactions with customers, employees are required to express proper emotions as a job …

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Exploring The Robustness Of A Surrogate-Based Ice Flow Model Calibration, Kyle Blum Dec 2023

Exploring The Robustness Of A Surrogate-Based Ice Flow Model Calibration, Kyle Blum

Physics

When simulating ice sheets using numerical models, model parameters have a great impact on the ice flow, velocity, and response to external forces, making them key factors in accurately predicting ice sheet behavior. In order to have confidence in modeled predictions of ice sheets, we must first have confidence in the physical models we use to simulate them. In order to have confidence in these physical models, we must first have confidence in our calibrations of these ice dynamics parameters. Researchers have been training neural networks to emulate expensive ice sheet models. These surrogate ice sheet models are designed to …

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Exploring Competing Gold System Models In The Valdez Creek Region, Clearwater Mountains, Alaska, Jane Marguerite Suhey Dec 2023

Exploring Competing Gold System Models In The Valdez Creek Region, Clearwater Mountains, Alaska, Jane Marguerite Suhey

Geosciences

Gold deposits located within the accretionary and subduction-related tectonic environment of south-central Alaska are interpreted to have formed via devolatilization of hydrous assemblages through regional metamorphism (orogenic model) or by intrusion-related hydrothermal processes (intrusion-related gold system model). The Valdez Creek mining district is located in the southern Clearwater Mountains of south-central Alaska along the intermontane-insular belt suture of the North American Cordillera. The 67-56 Ma south-vergent Valdez Creek shear zone resulted in the thrusting of North American-derived Maclaren schist (intermontane) structurally above lower greenschist-facies rocks of the Clearwater metasediments (Insular). The ~ 5km thick ductile shear zone preserves a complete …

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The Effects Of Summer Snowfall On Arctic Sea Ice Radiative Forcing, Hannah Chapman-Dutton Dec 2023

The Effects Of Summer Snowfall On Arctic Sea Ice Radiative Forcing, Hannah Chapman-Dutton

Geosciences

The decline in Arctic sea ice has had major impacts on the climate system, particularly relating to the ice-albedo feedback. Since fresh snow on top of bare or melting sea ice increases the surface albedo on local scales, the impact of summer snow events can have a negative radiative forcing effect, which could inhibit sea ice surface melt. In this study, we compared snow depth and meteorological data from buoys and satellite retrievals of surface and atmospheric conditions to identify and characterize summer snow accumulation case studies across the Arctic from 2003 to 2017. Clouds and Earth's Radiant Energy System …

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Environmental And Biotic Habitat Attributes Affect Rocky Intertidal Community Variability In Glacially Influenced Estuaries, Madeleine G. Mcarthur Dec 2023

Environmental And Biotic Habitat Attributes Affect Rocky Intertidal Community Variability In Glacially Influenced Estuaries, Madeleine G. Mcarthur

Marine Biology

Climate change is increasing the rate of glacial recession in high latitude coastal environments. The associated increase in cold, sediment-laden freshwater into the nearshore may alter a wide array of water attributes, which will likely have ecosystem-wide impacts. One of these potential impacts is a change in typical levels of ecological community variability, which can be an indicator of stress in response to an environmental impact. Fluctuation in community composition over time is natural and can be affected by environmental conditions, as well as by the presence of habitat forming, spatially dominant organisms. The goal of this study was to …

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Eavesdropping On Killer Whales: Distribution, Calling Rates, And Acoustic Abundance Of Fish-Eating And Mammal-Eating Killer Whales In The Gulf Of Alaska, Hannah J. Myers Dec 2023

Eavesdropping On Killer Whales: Distribution, Calling Rates, And Acoustic Abundance Of Fish-Eating And Mammal-Eating Killer Whales In The Gulf Of Alaska, Hannah J. Myers

Marine Biology

The widespread loss of apex consumers in marine, terrestrial, and freshwater ecosystems throughout the world has precipitated profound trophic cascades and switches to different ecological states. However, conserving top predators can deliver broad biodiversity benefits and improve ecosystem resiliency. Effective conservation and management policy is predicated on a species' distribution and abundance in a given area and time. In this dissertation, I provide new insight into killer whale (Orcinus orca) distribution, vocal behavior, and abundance in the Gulf of Alaska using passive acoustic monitoring and advance long-term monitoring capacity for this species. First, I describe the year-round spatiotemporal distribution and …

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Tiny Machine Learning For Underwater Image Enhancement: Pruning And Quantizaition Approach, Dr Khaled Nagaty, The British University In Egypt, Andreas Pester Dr Dec 2023

Tiny Machine Learning For Underwater Image Enhancement: Pruning And Quantizaition Approach, Dr Khaled Nagaty, The British University In Egypt, Andreas Pester Dr

Computer Science

Many people have expressed an interest in underwater image processing in a variety of fields, including underwater vehicle control, archaeology, marine biological studies, etc. Underwater exploration is becoming an increasingly important element of our lives, with applications ranging from underwater marine and creature research to pipeline and communication logistics, military use, touristic and entertainment use. Underwater images suffer from poor visibility, distortion, and poor quality for a variety of causes, including light propagation. The major issue arises when these images must be captured at depths greater than 500 feet and artificial lighting needs to be provided. Efficient algorithms and models …

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Marine Methane: Sources And Potential Adverse Effects, Sadia Mahmuda Dec 2023

Marine Methane: Sources And Potential Adverse Effects, Sadia Mahmuda

Engineering

Recently, there has been an increase in the occurrence of incidents involving spills of oil and natural gas, such as methane. The world experiences at least one major spill in each decade. An illustrative case is the Deepwater Horizon oil disaster in 2010 in the Gulf of Mexico. This catastrophe resulted in the discharge of about 205.8 million gallons of oil and 225,000 metric tons of methane gas into the Gulf of Mexico. More recently, in 2022, the Nord Stream pipeline leak occurred, which was the largest single methane release ever recorded. It released up to 500K tons of methane …

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Controlling Dust Concentration In A Fan Housing Using Settling Chambers And Water Sprays, Cristian Alonso Quevedo Delgado Dec 2023

Controlling Dust Concentration In A Fan Housing Using Settling Chambers And Water Sprays, Cristian Alonso Quevedo Delgado

Engineering

Dust generation is a consequence of various activities in the mining industry. The industry generates dust in quantities that can present occupational health hazard and equipment damage. A notable instance of equipment deterioration is the corrosion and erosion experienced by fan blades in underground mines. This thesis introduces settling chambers and water spray as feasible techniques commonly used for controlling dust in underground mine operations. The research aims to provide a low capital cost and maintenance-free system to capture the dust particles upwind of the main fan. The research focuses on an underground polymetallic mine in Peru, serving as a …

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Cultivating Better Writers Through Empowering Students, Jackie Butts, Tammie Sherry, Micheal Dicicco Dec 2023

Cultivating Better Writers Through Empowering Students, Jackie Butts, Tammie Sherry, Micheal Dicicco

Kentucky English Bulletin

No abstract provided.

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The Role Of Mentor Texts, Jean Wolph Dec 2023

The Role Of Mentor Texts, Jean Wolph

Kentucky English Bulletin

No abstract provided.

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Making Space For Adolescents Of Refugee Background In Public Libraries, Danielle S. Dejonge Dec 2023

Making Space For Adolescents Of Refugee Background In Public Libraries, Danielle S. Dejonge

Masters Projects

Refugee adolescents go through multiple transitions that affect identity while settling in their new country of relocation. The ability to recognize the complexity of identity in a healthy way is fostered by safe spaces of belonging that encourage agency. Libraries, as spaces already effectively serving diverse populations including refugee youth, have the resources to be a safe space for these adolescents. One resource that has been trending in libraries is a makerspace. Makerspaces offer multimodal activities, whether they be arts-based or STEM-based, that not only encourage critical thought, but also allow for development of belonging and agency for healthy dynamic …

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Movement Ecology, Survival, And Territorial Dynamics In Canada Lynx (Lynx Canadensis) Over A Cyclic Population Decline, Derek Arnold Dec 2023

Movement Ecology, Survival, And Territorial Dynamics In Canada Lynx (Lynx Canadensis) Over A Cyclic Population Decline, Derek Arnold

Biological Sciences

As the quintessential predator-prey cycle, research into Canada lynx (Lynx canadensis) and snowshoe hares (Lepus americanus) have led to many discoveries in population biology; however, much remains unknown about the nuances of their populations. In this dissertation, I examined the ways in which population cycles influence survival, reproduction, territoriality, and connectivity. First, I examined ways in which climate change induced shifts in fire regimes have affected lynx persistence in their current refugia. Lynx mainly sought out areas of higher hare density and lower cover, such as intermediately aged coniferous and deciduous forests. This type of forest was predicted to persist …

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Effects Of Browser Exclusion On The Willow Leafblotch Miner (Micrurapteryx Salicifoliella): Host Plant Availability, Oviposition, And Survival, Martha M. Cummings Dec 2023

Effects Of Browser Exclusion On The Willow Leafblotch Miner (Micrurapteryx Salicifoliella): Host Plant Availability, Oviposition, And Survival, Martha M. Cummings

Biological Sciences

Herbivores can affect the quality and quantity of their food plants in ways that indirectly influence the food resources and habitat available to other herbivores present. This study examined indirect interactions between a mammalian browser and an insect folivore that feed on shared plant species during different seasons. On a boreal floodplain in interior Alaska, we investigated how a history of winter browsing by moose (Alces alces) affected the behavior and performance of the willow leafblotch miner moth, Micrurapteryx salicifoliella in summer. Excluding moose browsing for 8 years did not change plant density, but strongly increased canopy height, vegetative cover …

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Avian Divergence And Speciation Across Beringia Examined Using Comparative Mitogenomics, K. A. Collier Dec 2023

Avian Divergence And Speciation Across Beringia Examined Using Comparative Mitogenomics, K. A. Collier

Biological Sciences

Accurate knowledge of divergence and speciation processes is critical for understanding key aspects of biodiversity. As a well-known, speciose group of vertebrates, an increased understanding of how birds diverge and speciate allows us to better manage extant avian diversity and understand how it develops over time. Additionally, birds often exhibit complex and variable patterns of divergence, resulting in complexes of taxonomic uncertainty. Filling gaps in our knowledge of divergence across time and space increases our ability to correctly identify and understand not just avian diversity but clade-level patterns in speciation processes. These higher-order findings give us tools to compare and …

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Alnus Viridis Ssp. Fruticosa Modulates Local Conditions To Influence Intra And Interspecies Growth, Jackson W. Drew Dec 2023

Alnus Viridis Ssp. Fruticosa Modulates Local Conditions To Influence Intra And Interspecies Growth, Jackson W. Drew

Biological Sciences

The Arctic is warming rapidly due to anthropogenic greenhouse gas emissions. Concurrent with warming, some Arctic plant communities have transformed from short statured evergreen and graminoid shrub tundra to tall deciduous shrubs in recent decades. As warming continues, plant-plant interactions will likely change and influence future community composition. Alnus viridis ssp. fruticosa (Siberian alder) is rapidly expanding across Arctic regions and is particularly important because Siberian alder is the Arctic's only large N-fixing shrub, may alter N-cycling to further influence both C-cycling and community composition as it spreads. This dissertation addressed two main questions to better understand how Arctic deciduous …

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Microplastics In Spotted Seal Stomachs From The Bering And Chukchi Seas In 2012 And 2020, Alexandria Sletten Dec 2023

Microplastics In Spotted Seal Stomachs From The Bering And Chukchi Seas In 2012 And 2020, Alexandria Sletten

Biological Sciences

Microplastics pose a significant threat to marine ecosystems across multiple trophic levels. Spotted seals (Phoca largha) are piscivorous and occupy one of the higher trophic positions in the Bering and Chukchi seas, putting them at risk of ingesting microplastics through prey. This project aimed to determine if microplastics are present in the stomachs of spotted seals harvested for subsistence purposes and compare their presence spatially between two harvest locations, Gambell and Shishmaref, AK. Microplastics are predicted to increase in the Arctic over time due to climate warming and subsequent deposition of microplastics from melting sea ice. Therefore, we examined stomachs …

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