Environmental Sciences and Policy


Recent Submissions

Now showing 1 - 20 of 81
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    (2023-05) Dennis, Hannah
    Quantifying contaminant leaching is important in the development of soil remediation standards that are protective of groundwater resources; however, factors impacting per- and polyfluoroalkyl substances (PFAS) leachability are not well understood. This research uses site specific soil, groundwater, and synthetic precipitation leaching procedure (SPLP) data to evaluate leachability of PFAS at aqueous film-forming foam (AFFF) release areas. Analysis includes regressing soil, groundwater, and SPLP data; comparing leachability to soil and contaminant properties; using the Environmental Protection Agency’s (EPA’s) Soil Screening Level (SSL) model to estimate soil concentrations estimated to result in groundwater exceedances of proposed maximum contaminant levels (MCLs); and comparing modeled results to field-measured results to determine the accuracy of the EPA SSL model. Regressions indicate close correlation between SPLP and soil concentrations (R2 =0.8677 to 0.9967, n = 30) but weaker correlation between SPLP and groundwater concentrations (R2 = 0.4703 to 0.6603, n = 21) and soil and groundwater concentrations (0.4069 to 0.6008, n = 21). Weaker correlations associated with groundwater are suspected to be associated with upgradient sources of groundwater contamination and the influence of physical soil properties on leaching rates, including reduced leaching associated with increased clay content in soil. Among individual PFAS studied, PFAS with greater organic carbon to water partition coefficient (Koc) values generally exhibited less leaching from soil to groundwater, consistent with greater sorption to soil. The SSL model indicates that PFOS and PFOA concentrations ranging from 1.45E-05 mg/kg to 1.26E-04 mg/kg may result in groundwater exceedances of MCLs; however, comparison to site-specific data indicates modeled SSLs may be 2 to 10 times lower than necessary for protection of groundwater.
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    (2023-05) Bartling, Janine
    The California coastline is 3,427 miles of ecological diversity that is home to 26.3 million people. While there are countless native species that can be found in the coastal areas of California, the California sea lion (Zalophus californianus) is a coastal marine mammal species that is found statewide. Sea lions share the same habitats as humans, including the need for fish and clean places to live and play. It is this similarity in requirements that makes the California sea lion a candidate for an umbrella species for determining if the coast is healthy and if the policies that are used for coastal health and protection are working. Identifying an umbrella species is a species that represents ecosystems or locations completely; California sea lions are an umbrella species due to their population distribution, natural history, and integration with human populations. Umbrella species differ from indicator species in their roles for the environment; both are ecologically important species. An indicator species may be limited to being an indicator of one factor on the environment, such as water quality. The role of the umbrella species is greater in that it encompasses some of the same responsibilities of the indicator species, but by protecting the species, you protect others that depend on it as predator, prey, and an indicator. The change in the role of the sea lions can be reflected in a change in how policy advocates for coastal health. Currently, most policies come from the national level, with some from the state level; it is carried out by state and local governments. By simplifying how policy advocates for coastal health, how it is monitored, and focusing on one species that can represent ecosystems along the coast, it will be more efficient and nimbler to make modifications on protections and policy. Using sea lions as an umbrella species in combination with centralizing the way coastal health is monitored and managed with make decision making more effective, particularly if the California Coastal Commission becomes the central agency that acts as an information and policy clearinghouse. Changing the California Coastal Commission would be necessary for there to be one organization dedicated to the health of the coastal area, the people that reside there, issues that affect it, and the other ecosystems that call the coastal area home. Even though the California Coastal Commission is currently engaged in some coastal preservation, this ecosystem focused management would shift focus to having the sea lions being used as early warning systems for coastal health, the management of the habitats being proactive instead of reactive and making management more accessible and usable by members of the community.
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    (2023-05) Visaya, Brianne
    In 2012, the City of Oakley and American Rivers completed the first Marsh Creek Restoration Project at Creekside Park. Marsh Creek, prior to restoration, was a trapezoidal engineered channel to mitigate flooding events affecting agricultural spaces and residential areas. This research was conducted to test the effectiveness of restoration projects and identify drawbacks that will be beneficial in the planning and design phases of future project sites. Several parameters were analyzed to understand the aftermath of the Marsh Creek at Creekside Park Restoration Project. This includes collecting water quality data, interpreting Landsat imagery analysis, performing physical characteristic assessments, and reviewing biological indicators. In addition, a compilation of fieldwork performed by American Rivers and Brianne Visaya prior-, during-, and post-restoration project completion was used to determine the success of enhancing the creek habitat and recreating the floodplain. Marsh Creek at Creekside Park Restoration Project’s monitoring program began in 2021. Within the two years, the results have remained the same. The three sites nearest to and within the proposed restoration area are classified as ‘in poor condition. The continuation of monitoring and data collection can better inform the condition of Marsh Creek.
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    (2023-05) Blizzard, Christopher
    Throughout the globe, Phragmites australis has gained prominence as an invasive species of concern. Eradication is the main focus of stakeholders for wetland restoration purposes due to the widely published negative effects of this species, which primarily concern a monocultural growth habit that can rapidly displace native species. However, with renewed focus in the 21st century upon sea level rise and climate change, wetlands are being lost at an unprecedented rate. Through a thorough review of literature on the subject, it is demonstrated that Phragmites australis has numerous potential benefits on long-term wetland stability through preventing and possibly reversing erosional processes, benefits water quality, and has potential for carbon sequestration and wildlife habitat. Management methodologies were also explored, and it was demonstrated that an integrated approach utilizing several methods should be utilized if eradication of this species be the long-term goal at a site. A Geographic Information Systems map was created of Blackwater National Wildlife Refuge, a site known for harboring a large population of the species, to further analyze the efficacy of management methods in a real-world scenario. It was found that management methods at the refuge are likely making a long-term impact upon the species’ prevalence, however continued management is necessary.
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    (2023-05) Kwasniewski, Hayley
    Green resource disparity between high and low socioeconomic neighborhoods in urban areas impact community environmental and ecological health, popularly measured by tree equity. Denver, CO is no exception. Urban parks play a critical role in ecosystem health and environmental functioning, and provide critical greenspaces needed to address green resource disparities. Connectivity within and between these parks depends on surrounding resources and, therefore, how the socioeconomic status of a park’s surrounding neighborhood relates to overall ecosystem health within the neighborhood’s park(s) is an important relationship to observe. This study attempts to understand how varying tree populations within neighborhoods of starkly different socioeconomic statuses relate to ecosystem health. Bee biodiversity and abundance is a bioindicator of ecosystem health. This study obtained bee population data from parks within Denver’s lowest and highest income neighborhoods. Both parks showed similar biodiversity of the neighborhood tree populations and the biodiversity of the bee populations. Furthermore, there seems to be a correlation between tree abundance and bee abundance. While more data and research are needed moving forward, this alludes to multiple intersecting relationships. Greenspaces in neighborhoods with low socioeconomic status and lower tree canopies have the capacity to host comparably biodiverse bee populations to high socioeconomic status neighborhoods when tree biodiversity between the two neighborhoods is similar, despite several present environmental injustices. These findings also indicate ways to improve ecosystem health across neighborhoods via growing tree canopies and diversifying tree populations. These results align with other research findings that show diversified and equitably distributed urban forests, supporting overall ecosystem health and functioning.
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    (2023-05) Romero-Heaney, Kelly
    Stream restoration is a valuable tool for protecting water supplies and infrastructure, restoring water quality and habitat, and recovering from drought, fire, or floods. Tension exists between proponents of projects that aim to restore the natural function of a stream (e.g. channel complexity, overbank flooding, riparian vegetation, and beaver activity) and downstream water-rights holders who are entitled to efficient deliveries of water. Stream restoration offers shared benefits to local economies, public safety, and environmental health and welfare, but the value of these benefits is not fully recognized under Colorado’s water law. Conversely, water rights owners need assurance that restoration activities will not diminish their legal right to divert water for beneficial use. Colorado’s water laws have been adapted to meet the evolving needs of its people through incremental changes, such as the statutory exemptions for household wells, stormwater detention ponds, gravel pits, and recently adopted legislation to allow Minor Stream Restoration Activities to occur without water administration. A workable and durable policy solution that allows for the restoration of a stream’s natural processes with sufficient limits and guidelines to protect water rights will require thoughtful, evidence-based conversation across interests.
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    An Interpretable Machine Learning Model to Explore Relationships between Drought Indices and Ecological Drought Impacts in the Cheyenne River Basin, USA
    (2023-05) Britton, Annie
    Rangeland ecosystems across the United States have significant biological, economic, and cultural value. However, the increasing frequency and severity of droughts across the country may lead to unforeseen impacts on these ecosystems. To address this challenge, this study aimed to identify relationships between drought indices and vegetation health in the Cheyenne River Basin, USA, using machine learning (ML) and explainable artificial intelligence (XAI) methods. Using Terra Moderate Resolution Imaging Spectroradiometers (MODIS), University of Idaho Gridded Surface Meteorological Dataset (gridMET), and Daymet data, the study employed XGBoost Regressor and Extra Trees Regressor models in unison with SHapley Additive exPlanations (SHAP) to evaluate predictive performance and the connections between drought indices, environmental variables, and the Normalized Difference Vegetation Index (NDVI). Tests of model performance demonstrated that the XGBoost model performed moderately well at predicting NDVI and was therefore useful for further XAI analysis with SHAP. SHAP explainer results showed that the Palmer Drought Severity Index (PDSI), the 90-day Standardized Precipitation Index (SPI), and snow water equivalent (SWE), were the most important predictors of NDVI values and are therefore closely associated with vegetation health in the study area. The findings of this study first demonstrate the feasibility and usefulness of applying XAI, an underutilized method in the drought space, to study ecological drought indicators. Secondly, results provide an understanding of which commonly used drought indices correlate with effects on vegetation health in the study area, as well as the specific directionality of these relationships. These results can be used to inform drought research and monitoring practices and anticipate ecological drought impacts in the Cheyenne River Basin.
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    Utilizing Synthetic Aperture Radar, Stream Gages, and LiDAR for Cross-Section Analysis of Surface Water Extent across a Military Installation’s Bottomland Hardwood Forest
    (2023-05-05) Hults, Graham
    This research provides an original analysis approach to the hydrodynamic factors impacting drainage and surface water extent across four cross-sections of a bottomland hardwood forest floodplain adjacent to a military installation. This was achieved through depiction of flood extent and drainage following a 1.86” precipitation event that occurred on March 3, 2023. Synthetic Aperture Radar (SAR) image acquisitions were collected on March 5 near peak-inundation and four days following to depict drainage. A subsequent semi-dry image was captured on April 9, 2023, to serve as a control. In addition to surface water extent provided through SAR, stream gages available through the USGS containing water height data within the area of interest and discharge rates upstream and downstream were analyzed. Flow impacts and water diversion into the floodplain from large woody debris obstructions were visualized through LiDAR point clouds and an open-source 3D modeling software. The difference between the surface water extent on March 5th and March 9th depicts an increase of surface water presence by 0.6 km². This indicates a 4.50% increase in total surface water area across the floodplain scene over the 4-day period. This supports the hypothesis for source identification of potential hydrologic-impact variables through further analysis of the railroad structure and its impact on the surface water extent and drainage across cross-section three. The stream gage at Silver Creek Highway-161 which provided water height readings had a correlation of 0.89393 to the Troy stream gage upstream which produced discharge readings in cubic feet per second (cfs). This high correlation infers that these average discharge readings can be incorporated into future hydraulic models for these cross-sections for channel-floodplain interface analysis (Stone, et al., 2017) or an evaluation of geomorphic response to changes in wood loading (Brummer, et al., 2006).
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    Sustainable Urban Agriculture: Are Vertical Farms a Solution to Urban Food Deserts?
    (2023-05-08) Luongo, Tara
    Food deserts are a major issue in urban areas across the United States. With Bedford–Stuyvesant having one of the highest bodega-to-supermarket ratios in New York City, it is essential to look at viable options to mitigate this food desert. The State of New York and New York City have become hotspots for vertical farming. A few of the larger players, such as Square Roots, Farm.One, and Gotham Greens have located in New York attracted by the city’s population size and resources. This study assessed the feasibility of a vertical farm to understand if they are a viable option to eradicating food deserts. Unfortunately, vertical farms will not be able to support entire neighborhoods within New York City. The largest vertical farm used in this study, which was calculated using 90,000 ft2, could only serve a maximum of nine percent of the Bedford–Stuyvesant populations required annual vegetable intake. Vertical farms are not the sole solution; however, it appears promising that vertical farms could be part of the solution. New York City must act in developing food policies by creating fast food limits and promoting health food retailing, improving supermarket access, and increasing access to farmers markets within lowincome communities.
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    (2022-12) Auffredou, Mel
    While electric vehicle (EV) consumption is frequently lauded as a necessary sustainable solution, EV production is inextricably linked with severe social suffering in upstream mining communities in the Democratic Republic of the Congo (DRC). The objective of this project is twofold: to review the historical colonial processes that have created the current-day cobalt sector in DRC and to analyze whether or not renewable energy transitions that rely on DRC cobalt can accurately be deemed sustainable. We accomplished this via a literature review and an analysis of the DRC cobalt sector using the United Nations Sustainable Development Goal (SDG) framework. This project reviews the DRC cobalt sector in relation to the following SDGs: SDG 1, Zero Poverty; SDG 3, Good Health and Well-Being; SDG 8, Decent Work and Economic Growth; SDG 15, Life on Land; and SDG 16, Peace, Justice, and Strong Institutions. The results of this project demonstrate that cobalt mining creates little benefit for upstream mining communities and results in significant challenges to sustainable development. The literature indicates that the DRC government’s inequitable allocation of land and mineral resources is a significant barrier to sustainable development. The ultimate result of this project is a critique of consumptive climate solutions that do not disrupt underlying power imbalances in renewable energy supply chains.
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    Building a Texas Water Data Hub as a model for National Water Data Infrastructure
    (2022-12) Swanson, Kelly
    Findable, Accessible, Interoperable, Reusable (FAIR) water data is a buzz word in the industry for good reason (Making Public Data FAIR, 2018). Without these objectives, poor water data across the United States will continue to cripple the ability of decision makers to manage and develop sustainable practices (Building Data Infrastructure, 2022). In an effort to implement these standards, this research was designed to first understand the past and current water data infrastructure throughout Texas and the United States and then create a findable, accessable, interoperable, and reusable (FAIR) water data hub (Making Public Data FAIR, 2018). An important part of this effort was to include stakeholders and decision makers from the water data industry. This research provides an overview of initial data collection and follows with detailed updates to water categorization and standards, stakeholder engagement and best practices, the creation of the Texas Water Data Hub and finally, recommendations to expand this state effort to a national level. The discussion speaks to the complexity of organizing water data due to the overlapping needs of such a project. The conclusion points out the additional challenges to scaling up these procedures to a national level. All of these efforts are part of building FAIR water data and is essential in our increasing need and care of water.
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    Advancing Environmental Equity: Environmental Justice Organizational Directory and Toolkit, 2022
    (2022-12) Morton, Kaitlin
    Too often grassroots groups and environmental justice (EJ) organizations are not linked to each other (Bullard, 2000), exist in silos, and are isolated from the resources and/or organizations in which they can collaborate and benefit from. This thesis, in the form of a directory, is designed as a planning, organizing, networking, and community empowerment tool to bring organizations and underrepresented stakeholders to the table in planning summits, conferences, and workshops. The goal of this thesis is three-fold: 1) to offer a conventional analysis on reoccurring and longstanding, environmental justice themes and inequalities burdening low-income and/or people of color in the United States; 2) to compile and document a directory of grassroots environmental justice and civil rights organizations that currently operate and serve in Alaska, EPA Region 4 (Alabama, Florida, Georgia, Kentucky, Mississippi, North Carolina, South Carolina, Tennessee and 6 Tribes), and EPA Region 6 (Louisiana, Arkansas, Oklahoma, New Mexico, Texas, and 65 Tribal Nations); and 3) to track and examine enabling policies, resources, and tools that serve to create a more equitable environmental justice landscape in the United States.
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    (2022-12) Walker, Emily
    The current Biden administration has aggressive goals to dramatically increase solar deployment across the United States. While solar is highly sustainable compared to fossil fuel electricity sources, solar modules (colloquially known as solar panels) can contain hazardous waste and solar module recycling is still in its infancy. High quality solar equipment results in less waste overall, making it pivotal to the future of solar. This study uses solar installation data from the Lawrence Berkeley National Laboratory to examine the impact of comparison shopping completed through EnergySage, the United States’ leading solar quote marketplace, on the quality of installed solar equipment. It finds that EnergySage installations include modules of higher efficiency, modules of greater wattage capacity, and more advanced module and inverter technology, compared to installations completed external to EnergySage. It also finds that over the past three years, despite supply chain constraints severely impacting the solar industry, modules have significantly increased in efficiency and capacity, at roughly the same rate for installations completed through and external to EnergySage. However, over these same three years, EnergySage installations consistently contained higher quality equipment, suggesting that competition may drive installers to quote and solar consumers to request and choose higher quality solar equipment.
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    (2022-12) Yapo, Alia
    In 2007, as a result of drastic population decline over the last century, European eels were added to Appendix II of CITES in order to regulate and limit its trade exploitation. However, illegal trade of these species is still rampant to meet consumption demand in Asia and Europe. This suggests that CITES is not armed with the tools necessary for effective implementation and not sufficiently using these tools; therefore, amendments to this treaty are necessary. A review of government reports and literature indicate existing gaps in European eels morphological and life cycle research along with technological limitations that contribute to poor implementation of CITES regulation for European eels resulting in significant presence of illegal trafficking. To address these limitations, CITES amendments are recommended to allow for more effective mitigation of European eel trafficking. However, an effective approach to trade regulation requires a dynamic policy approach. Relying on one instrument, such as CITES, to possess all the tools to deter illegal wildlife trafficking is unreasonable. Rather, multiple policies that employ different sets of tools should be implemented in a complementary way to promote sustainable trade practices.
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    The fifteenth and sixteenth centuries were a time of exploration and colonization. Fueled by the necessity to establish new trade routes and profit potential by sea, colonists flocked to the Neotropics. Colonization brought a convergence of cultures, along with exotic and non-native biota, as well as the development of new social and economic systems and the rapid transformation of the regional landscape. To understand the world we currently inhabit and our current ecological catastrophe – a world where food shortages, the mass die-off of coral reefs, and wildfires are common occurrences – we need to look at colonialism and its roots. Thus, the heart of the paper lies in examining the past to gain insight into the future. Archaeology and its many subsets are well-suited to examine the consequences of human eco-dynamics across any region, including the Neotropics. Through the analysis and synthesis of the collaborative and collective research of archaeologists and by employing the standpoints of cultural and medical anthropologists, economists, environmental engineers, and other experts who study human-environmental relationships, this paper seeks to understand and shed light on the social, economic, environmental, and engineered factors of colonialism that have created an environmental legacy that persists in the Neotropical region today. As the global community faces the challenges of climate change, this paper looks into the past through the lens of historical ecology to better understand the anthropogenic changes to the earth system and humanity’s interrelationship with the biosphere over time.
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    (2022-04) Aaby, Kaitlin
    Climate change is expected to have very intense impacts on the climate of Denver, Colorado. There will be an increase in the severity of heat waves, droughts, wildfires, and air pollution. At the same time, there are over 9,000 individuals experiencing homelessness every day in the city. Previous studies have noted that various social and economic factors, as well as constant exposure to the elements, lead to higher vulnerability amongst the homeless. This research aims to illuminate how climate change affects the homeless living in Denver and evaluate local responses. Understanding these concerns will help to better inform climate mitigation and adaptation policies. A review of the literature demonstrates how the homeless will experience greater mortality and suffering because of extreme heat and poor air quality in Denver. However, as of 2022, the City and County of Denver have not made sufficient efforts to include unhoused populations in their climate justice efforts for mitigation, adaptation, and resiliency to climate change. Interviews conducted with those who have lived experience of homelessness suggest that there is a great need for additional resources and policies tailored to their concerns. Improving the homeless communities’ quality of life can increase their resiliency to climate change. This means improving local housing, hygiene, food, and mental health services. Safer and cleaner outdoor spaces and shelters need to be provided to those in need of emergency or temporary shelter. Denver’s camping ban is not an effective policy measure to help the homeless in the face of the changing climate, as it leads to negative physical and mental health outcomes, as well as prevents people from creating shelter from the elements. Climate policies should consult the unhoused and formally address their vulnerability within Denver. Further research is needed to properly assess where and how the homeless will be most affected by the changing climate. Education and advocacy are also important to consider moving forward. The homeless should be given resources to protect themselves from changing climate patterns, and there is a great need for more compassion toward the homeless.
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    (2022-05) Kleiner, Andrew
    Island Beach State Park (IBSP), a barrier island located off the coast of New Jersey, is a state park with noted populations of a variety of organisms that includes numerous small mammals such as Didelphis virginianas (Opossum), Procyon Lotor (Raccoon), Slyvilagus floridanus (Eastern Cottontail), and Vulpes Vulpe (Red Fox). To estimate the species abundance of these small mammals, an unmarked camera trap study was operated continuously for 28 days. The objective of the study is the creation of a baseline species abundance for each target mammal, from which future studies can be compared as there are no present recorded abundance estimates on these species in the park. Unmarked camera traps were placed to capture a representative sample at 30 random 0.8-kilometer spaced locations. Of the 30 cameras placed, 28 successfully functioned for the duration of the study, recording 166 successful captures of the target mammal species. Using an Rstudio based Time to Event model species abundance estimates were generated. The estimated species abundance of Vulpes vulpe on IBSP is approximately 39 with a confidence interval of 26-57 and a standard error of 7, the species abundance of Procyon lotor on IBSP is approximately 132 with a confidence interval of 96-182 and a standard error of 21, and the species abundance of Slyvilagus floridanus on IBSP is approximately 173 with a confidence interval of 125-240 and a standard error of 29. These novel abundance estimates are a baseline to understand trends in the population of these organisms in Island Beach State Park as future studies can increase the observation time and locations of study in the park to further refine these estimates.
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    (2021-05) Averett, Adrienne
    Over the past 40 years, the ecological conservation research and policy community has advocated for the inclusion of Indigenous Knowledge and diverse cultural and spiritual worldviews in conservation science, management, and decision-making. Biodiversity conservation can benefit from the deep history of applied Indigenous or Traditional Ecological Knowledge (TEK). Additionally, Western scientists and conservation managers have a responsibility to acknowledge and remedy the historic and current Euro-American institutions and power mechanisms that impede knowledge mutualism, equity, and Indigenous agency in conservation outcomes. The objective of this research was to create a systematic literature map of Indigenous knowledge contributions to biodiversity conservation science in the United States, during 2009 - 2021, to: 1) understand the nexus of Indigenous Knowledge and Western Scientific Knowledge in the conservation biology literature; and 2) identify knowledge gaps to inform future work. Web of Science was queried using Indigenous knowledge, ecological system, and knowledge interaction search terms informed by the literature. A total of 37 articles, merged into 33 records, were coded and mapped to evaluate study location, focal issue, Indigenous knowledge contributions, underlying institutional mechanisms, and knowledge gaps. Results of this research indicate that Indigenous knowledge is informing a diverse conservation science and management evidence landscape. Indigenous Knowledge - Western Science blending or mutualism was reported in all the studies, however additional research is needed to evaluate the breadth of Indigenous knowledge sources and quality of mutualistic outcomes. Institutional mechanisms and power inequities continue to limit Indigenous self-determination in conservation science and management in the United States. Mapped records indicate the importance of elevating Indigenous environmental management frameworks, eco-cultural data confidentiality and ownership practices, acknowledging and compensating Indigenous partners for their contributions and participation, and most importantly, building respectful, trust-based relationships with Indigenous leaders and communities. Systematic literature reviews are an underutilized tool for exploring Indigenous and Western conservation science relationships in the United States. Results from this literature mapping review provide initial insights on Indigenous-Western Science conservation knowledge relationships in the United States and provide a framework for future research in this area.
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    (2021-05) Urick, Robert
    The eastern oyster (Crassostrea virginica) is a keystone species in Chesapeake Bay, providing nutrient and sediment filtration and crucial habitat. While the eastern oyster was once abundant in Chesapeake Bay, over-harvesting, pollution, and disease have led to massive declines in their populations, with some estimates as less than one percent of historical levels. Dredge harvesting has flattened many of the three-dimensional reef structures, leading to a major decline in important habitat. To aid in oyster reef restoration, the State of Maryland implemented sanctuaries – areas where commercial harvest is entirely banned – and separated them from Public Shellfish Fishery Areas (PSFAs), where harvest is permitted. These sanctuaries have been politically controversial with watermen disputing the effectiveness of sanctuaries and lobbying to have them opened for harvest. This research utilized data gathered in annual dredge surveys conducted by the Maryland Department of Natural Resources to test the hypothesis that there were statistically significant differences in mortality, number of spat, and biomass in oyster bars in sanctuaries to bars in PSFAs from 2010 to 2019. Utilizing RStudio, it was found that there were only statistically significant differences in mortality across all bars and in a single geographical code, and in the number of spat per bushel across all bars and in low salinity bars. Most comparisons were not statistically significant, likely due in part to the high level of variability in the data and small sample sizes. Comparison of the means in every individual year from 2010 to 2019 showed broadly similar trends in sanctuary and PSFA bars while showing a greater mean biomass after 2013 for sanctuary bars compared to PSFA bars. Further research on the statistical differences in sanctuary and PSFA bars should focus on a narrower region with similar environmental factors.
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    (2021-05) Drummond, Olivia
    Human-carnivore conflict (HCC) remains a significant threat to carnivore populations around the globe. HCC from depredation, car strikes, and illegal hunting in southern California with the mountain lion (Puma concolor) causes significant population decline and genetic bottlenecking. Additionally, fires in the region are becoming more frequent and intense, causing vegetation-type change altering habitat used by mountain lions and their prey. This study aimed to investigate the influence of fires and vegetation type change have on HCC with a southern population of mountain lions in San Diego county using mortality data as the metric for conflict. Geographic information systems (GIS) were used to map various environmental conditions including slope, elevation, vegetation health, land cover, fire severity, human population density, and distance to streams and secondary roads. These factors were sampled at each mountain lion mortality point and modeled to determine their influence. Fires and land cover were the least influential on human-related mountain lion deaths, while the distance to secondary roads, elevation, and vegetation health had the most significant influence. Understanding how environmental conditions influence HCC with mountain lions can better prepare wildlife managers to reduce conflict, educate community members, and ensure the survival of predators into the future.