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Full-Text Articles in Physical Sciences and Mathematics

Visual Characteristics Of Walleye Pollock And Chinook Salmon: Modeling Theoretical Visual Space And Target Contrast Of Trawling Materials In The Bering Sea, Rebecca Haehn Jan 2023

Visual Characteristics Of Walleye Pollock And Chinook Salmon: Modeling Theoretical Visual Space And Target Contrast Of Trawling Materials In The Bering Sea, Rebecca Haehn

WWU Graduate School Collection

Walleye pollock (Gadus chalcogrammus) and Chinook salmon (Oncorhynchus tshawytscha) are economic and cultural resources in Alaska. Chinook salmon bycatch is a large concern within the pollock fishery. Current strategies to reduce salmon bycatch include modifying trawl gear by implementing artificial light near or on escapement panels to increase salmon escapement. The visual characteristics of pollock and Chinook salmon were investigated to understand the perception of trawl gear. The visual pigments of each species were measured using microspectrophotometry (MSP). Pollock were dichromats with spectral sensitivity ranging from 449nm–518 nm and Chinook salmon were trichromats with sensitivity ranging …


Impact Of Riverbank Lupine (Lupinus Rivularis) On Grand Fir (Abies Grandis) Ectomycorrhizal Symbioses, Andrew Labay Jan 2023

Impact Of Riverbank Lupine (Lupinus Rivularis) On Grand Fir (Abies Grandis) Ectomycorrhizal Symbioses, Andrew Labay

WWU Graduate School Collection

Lupine (Lupinus rivularis) is used in the revegetation of coarse sediments surrounding the Elwha basin in Washington State due to its ability to improve soil conditions. Previous research illustrated that seeding lupine with conifers increased growth and foliar nitrogen, however, decreased ectomycorrhizal (ECM) root colonization, an important symbiosis for conifers used in restoration. We hypothesized the observed decrease in ECM may be due to lupine increasing soil nitrogen, negating the need for a fungal symbiont. To investigate this, we explored the interaction between lupine and ECM colonization of grand fir (Abies grandis) in both a field …


Generations Of Stewards: Re-Indigenizing Youth Leadership, Learning, And Conservation Education, Drew Slaney Jan 2023

Generations Of Stewards: Re-Indigenizing Youth Leadership, Learning, And Conservation Education, Drew Slaney

WWU Graduate School Collection

My thesis is an exploratory case study into epistemologies (or worldviews) supported by organizations and agencies that develop outdoor conservation and education programs for Native youth called Native Youth Stewardship Programs (NYSPs). This subject relies on the content developed by Medin and Bang (2014) who state that an under-representation of Indigenous peoples in Science, Technology, Engineering, and Mathematics (STEM) fields is largely the result of epistemological conflicts between educators and Indigenous students. I hypothesize that there is a considerable epistemological difference between the conservation entities developing programs to engage Native youth. These differences may create significant barriers with youth recruitment, …


Value Mapping And The Community Wildfire Protection Planning Process In Entiat, Wa, Katharine Kiendl Jan 2023

Value Mapping And The Community Wildfire Protection Planning Process In Entiat, Wa, Katharine Kiendl

WWU Graduate School Collection

Community Wildfire Protection Plans (CWPP) offer benefits for communities effected by wildfire risk and ignitions. CWPP’s serve several functions; they develop interlocal agreements between agencies that provide wildfire response and management, they develop hazard mitigation and wildfire education programs, and they define areas as wildland urban interface (WUI). The CWPP drafting process can impact the resources available to a wildfire risk community. However, despite the impact to communities effected by wildfire, CWPP planning is considered a categorical exclusion under the National Environmental Policy Act (NEPA) allowing CWPP’s to be developed without public review. Given that community plans with public participation …


Distribution And Mixotrophy Of Cryptophyte Phytoplankton In The Northern Gulf Of Alaska, Megan O'Hara Jan 2023

Distribution And Mixotrophy Of Cryptophyte Phytoplankton In The Northern Gulf Of Alaska, Megan O'Hara

WWU Graduate School Collection

The Northern Gulf of Alaska (NGA) is a productive subarctic marine ecosystem that supports high abundances of plankton, fishes, seabirds, and mammals. Research has shown that this high productivity is primarily controlled by seasonal and spatial heterogeneity in the lower trophic level food web. Marine cryptophytes are a crucial, yet understudied, phytoplankton group in the NGA. Cryptophytes have the capacity for mixotrophy (acquiring energy through photosynthesis and feeding) which can improve trophic transfer efficiency, increase cellular growth rates, and improve retention of nutrients in the water column. Field samples collected in spring, summer, and fall 2021 surveyed the contribution of …


The Economic And Emissions Reduction Potential Of Air Source Heat Pumps As A Replacement For Natural Gas And Electric Resistance Space Heating In The Contiguous United States, Joshua Schraer Jan 2023

The Economic And Emissions Reduction Potential Of Air Source Heat Pumps As A Replacement For Natural Gas And Electric Resistance Space Heating In The Contiguous United States, Joshua Schraer

WWU Graduate School Collection

It is widely believed that to reduce CO2 emissions the best strategy is to electrify everything, decarbonize the grid, and improve energy efficiency. This research looks specifically at the use of air source heat pumps (AHP) as a tool to reduce the CO2 emissions of heating energy in the residential sector. The landscape of residential energy use is complicated by a broad range of factors. We compare AHP, natural gas (NG), and electric resistance (ER) heating using data from energy prices, temperature, appliance efficiency, building efficiency and marginal emissions data from 2019 as well as modeled data of …


Contaminants Of Emerging Concern In Puget Sound: Screening, Prioritization, And Estrogenic Mixture Response Assessment, Maya Faber Jan 2023

Contaminants Of Emerging Concern In Puget Sound: Screening, Prioritization, And Estrogenic Mixture Response Assessment, Maya Faber

WWU Graduate School Collection

Contaminants of emerging concern (CECs) are chemicals used in daily life, such as pharmaceuticals, personal hygiene products, steroids, pesticides, and flame retardants. The environmental occurrence and toxicology of CECs are poorly characterized, and they are generally unregulated. Traditional toxicological approaches rely on in vivo methods to test whole organisms for apical endpoints, including survival, reproduction, and growth. This is time-consuming and costly, both financially and in terms of laboratory animal well-being, limiting ecotoxicological data for CECs. To overcome this challenge, we are utilizing alternative approaches, including New Approach Methodologies (NAMs), to perform a screening-level evaluation of CECs present in Puget …


Learning From Traditional Ecological Knowledge: Paralytic Shellfish Toxins In Butter Clams, Jackelyn Garcia Jan 2023

Learning From Traditional Ecological Knowledge: Paralytic Shellfish Toxins In Butter Clams, Jackelyn Garcia

WWU Graduate School Collection

Anthropogenic forcing of marine ecosystems is disproportionately impacting Indigenous food systems and the health of coastal Indigenous communities. With increasing harmful algal events, there is rising concern for access and health of coastal communities who rely on shellfish for commercial, food, subsistence, and ceremonial harvest. In the U.S West Coast, the dinoflagellate Alexandrium spp. may produce paralytic shellfish toxins, which can cause shellfish to become toxic and is of especial concern. While recent research has led to greater awareness of the risks associated with paralytic shellfish toxins (PSTs), the concern for harmful algae is not new. Coastal Indigenous communities have …


The Race Toward Carbon Neutral Ecotourism: Leveraging Life Cycle Analysis And Natural Climate Solutions For A Community Adventure Event, Ted Tarricone Jan 2023

The Race Toward Carbon Neutral Ecotourism: Leveraging Life Cycle Analysis And Natural Climate Solutions For A Community Adventure Event, Ted Tarricone

WWU Graduate School Collection

Global tourism is an interconnected framework of multiple industries that is influenced by and has impacts on economic, social, and environmental structures. Currently, tourism accounts for roughly 8% of global greenhouse gas emissions, which is expected to grow with industry expansion. To develop a scalable system for ecotourism assessment, emission reduction, and solutions to meet carbon neutrality, a small (n=3894 participants) adventure relay race named Ski to Sea in Bellingham, WA was studied. A life cycle analysis (LCA) conducted on the race showed similar proportional results to other tourism LCAs, where transport made up over 80% of the 325 tonnes …


Impact Of Carbonaceous And Inorganic Nanomaterial Chemistry On Polymer Additive Release From Weathered Epoxy Composites, Haley Sefi-Cyr Jan 2023

Impact Of Carbonaceous And Inorganic Nanomaterial Chemistry On Polymer Additive Release From Weathered Epoxy Composites, Haley Sefi-Cyr

WWU Graduate School Collection

Nanomaterials (NMs) are small (< 100 nm), reactive, chemical species that can often be used as polymer fillers to improve mechanical strength and slow the degradation of polymer nanocomposites (PNCs). Polymers can undergo physical and chemical weathering which can result in increased release of polymer additives and non-polymerized monomers from the polymer matrix. This project aimed to study how NM chemistry and environmental weathering impacts the release and transformation of relevant PNC systems. Bisphenol A diglycidyl ether (BADGE) PNCs were synthesized containing titanium dioxide (TiO2), multi-walled carbon nanotubes (MWCNT), or graphene oxide (GO) NMs. These composites were subjected to either simulated or natural weathering conditions to quantify and characterize their capacity to leach endocrine-disrupting chemicals. Environmental variables, including temperature and ultra-violet (UV) light, were investigated for their impact on additive release. Fourier-transform infrared spectroscopy and Raman microscopy were used to characterize the PNCs which were leached in water for one to five days at 25, 45, or 65 °C. The degree of weathering also varied from no weathering, outdoor weathering, or simulated weathering using UV light. Leachates were analyzed using high-performance liquid chromatography quadrupole time-of-flight mass spectrometry to quantify release of bisphenol A (BPA), tert-butylphenol (TBP), and nonylphenol (NP). There were significant differences between NM types for PNCs weathered outdoors and leached at 25 °C for 24 h, however only TBP was detected in the leachate. When compared to the blank epoxy, GO PNCs leached significantly less in the UV and in May outdoor weathered experiments, MWCNT PNCs leached significantly less when weathered outdoors in May and June, and TiO2 PNCs leached significantly less when UV weathered. Each of the NMs has potential to decrease TBP release through sorption or photodegradation. The carbonaceous NMs (GO and MWCNT) may sorb TBP, inhibiting its release, while TiO2 may photodegrade TBP. The unweathered PNCs leached the most TBP, followed by UV weathered, and then outdoor weathered. A possible explanation for this is photodegradation of TBP by UV light in the UV- and outdoor-weathered experiments leading to removal of TBP prior to leaching. Future experiments should include additional sorption trials and long-term natural weathering with microplastic generation to further explore the release and degradation mechanisms.


A Characterization Of Hyporheic Temperatures With Applications For Salmon Habitat Restoration In A Thermally Impaired River, Sydney Jantsch Jan 2023

A Characterization Of Hyporheic Temperatures With Applications For Salmon Habitat Restoration In A Thermally Impaired River, Sydney Jantsch

WWU Graduate School Collection

This thesis project is part of an ongoing study assessing the effectiveness of a potentially innovative habitat restoration strategy for Pacific salmon in thermally impaired rivers. This strategy uses engineered log jams (ELJs) to create pockets of cool-water refuge by forming deep scour pools and promoting localized upwellings of shallow subsurface (i.e., hyporheic) water. This project seeks to characterize the relationship between hyporheic temperature and overlying surface stream temperature to elucidate the extent to which hyporheic upwellings can deliver cool water to ELJ-formed pools during the summer low-flow season. Among six sites within a 2.7 km-long study reach on the …


Glacial Loss And Threatened Fish: The Future Of Mount Rainier’S Cold-Water Bull Trout Habitats, Kathleen C. Ewen Jan 2023

Glacial Loss And Threatened Fish: The Future Of Mount Rainier’S Cold-Water Bull Trout Habitats, Kathleen C. Ewen

WWU Graduate School Collection

Glaciers play a key ecological role in the river systems that they support. Cold-water reaches supplied by glacial ice serve as critical habitats for aquatic organisms that rely on specific thermal ranges to survive. Federally threatened Bull Trout (Salvelinus confluentus) require very cold temperatures, like those found in glacial systems, to complete their life cycles. However, glaciers are retreating due to climate change and are expected to continue diminishing throughout this century. Decreased glacial extent could result in warmer stream temperatures downstream from glaciers and, depending on the magnitude of stream temperature increase, cold-water habitats relied upon by Bull Trout …


Evaluating Leaf Trait Variation In High Elevation Bristlecone Pine (Pinus Longaeva) Under Increasing Water Stress: Insights From Needle Length, Stomatal Density, And Cambial Growth, Audrey Salerno Jan 2023

Evaluating Leaf Trait Variation In High Elevation Bristlecone Pine (Pinus Longaeva) Under Increasing Water Stress: Insights From Needle Length, Stomatal Density, And Cambial Growth, Audrey Salerno

WWU Graduate School Collection

Increasing aridification caused by climate change is altering growth patterns in trees. There is revived attention on how foliar traits respond to climate and the relationship of these traits to ring width. Bristlecone pine (Pinus longaeva, DK Bailey), a long-lived conifer found at high elevations in the cool and dry intermountain west of America, is used in paleoclimate reconstructions by measurement of their annually resolvable tree rings. The species also has annually datable needles retained on their branches for an average of 45 years making it the ideal subject for research on foliar trait and growth relationships under …


Trophic Transfer Of Metals From Seaweed To Shellfish In An Aquaculture System, Sophia Boyd Jan 2023

Trophic Transfer Of Metals From Seaweed To Shellfish In An Aquaculture System, Sophia Boyd

WWU Graduate School Collection

Seafood, including fish, shellfish, and seaweed, are an important source of nutrients that could meet some of the increasing demand for food globally. In addition to nutrients, chemical contaminants can also be acquired from the environment by primary producers. Seaweeds take up a variety of inorganic and organic contaminants, including metals, that may pose risks to human health. Through trophic transfer, organisms can accumulate elevated levels of contaminants from consuming lower trophic-level organisms. Since particulate organic matter, including seaweed detritus, is a food source for filter-feeding bivalves, contaminants present in seaweed could transfer to shellfish via ingestion. The purpose of …