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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

The Effects of Drifting Fish Aggregating Devices on Bycatch in the Tropical Tuna Purse Seine Fisheries in the Atlantic and Indian Oceans

Snouck-Hurgronje, Julia 01 January 2016 (has links)
Thousands of floating objects, known as drifting fish aggregating devices (dFADs), are released every year by commercial tropical tuna purse seine vessels in the three equatorial oceans to aggregate tuna and increase catch. The escalation in the number of dFADs deployed over the last three decades has caused changes in fishing effort that are poorly reflected in traditional indices of purse seine effort and catch per unit of effort (CPUE). In addition, concerns have been raised regarding the impacts of such high numbers of dFADs being deployed on both catch and bycatch species. I studied two aspects of dFAD deployments in order to clarify how dFADs are used by purse seiners and how they affect the magnitude of bycatch. My specific goals were to determine how often purse seine vessels fish on the dFADs they deploy and how regional dFAD density affects the magnitude of bycatch and catch. I analyzed commercial data, independent observer data, satellite buoy trajectories, and estimated floating object densities from the French tropical tuna purse seine fisheries in the Atlantic and Indian Oceans to examine these relationships. My results indicate that only 2.7-20.6% of dFAD fishing sets were on the dFADs that French purse seiners deployed over the period 2007-2013. Although this percentage increased over time, such a low percentage suggests that French vessels do not primarily increase CPUE by using the dFADs they deploy for directed fishing. If French purse seiners are not mainly using their own dFADs in this manner, then using a metric of nominal effort based on individual vessel activity is unlikely to produce reliable CPUE estimates for the fishery. While information about how often purse seiners fish on their own dFADs could be incorporated into indices of fishing effort, it may be just as important, if not more so, to quantify the collective component of dFAD releases for overall fishing effort. The results for the second objective showed that average dFAD density had a relatively weak relationship with total bycatch biomass. There was no statistically significant effect on mean total bycatch biomass, but dFAD density was related to heteroscedasticity in bycatch biomass. In particular, there was a significant negative relationship between dFAD density and the upper quantiles of the bycatch biomass distribution, suggesting that dFAD density determines the upper bound for bycatch biomass caught per set. These relationships were not constant across species, however, as the five most prevalent bycatch species (i.e., those caught in the greatest number of sets) showed a mix of positive, negative, or no relationships to dFAD density. The total biomass of catch increased significantly as average dFAD density increased both at the mean and throughout the majority of the distribution, although this effect only explained a small fraction of the total variance in catch biomass. at this time, the low amount of variance explained and the inconsistent impact of average dFAD density on bycatch and target species indicate that it would be ineffective to mitigate bycatch levels in these fisheries by attempting to control regional dFAD densities.
52

Local Environmental Management, A Case Study: The Virginia Wetlands Act, 1972-1974

Jones, John Claiborne 01 January 1976 (has links)
No description available.
53

Relative Risk Assessment for Cape Hatteras National Seashore

Buie, John Cary 01 January 1996 (has links)
No description available.
54

Mattanock Town Restoration Plan

McCarter Grigsby, Katlin 01 January 2023 (has links) (PDF)
Mattanock Town's Restoration Plan is a science-based restoration process that evaluates the site's history, the tribal history, and the most current research to maximize native habitats, enhance coastal resilience, and reconnect the Nansemond people to the local river. Restoration priorities include increasing native plant species, incorporating oyster habitat, and addressing erosion. This plan details how synthesizing existing and new physical, biological, and cultural information can help the Nansemond Indian Nation prioritize projects that benefit their community and the surrounding environment.
55

Catfish Management in the James River, Virginia

Lanier, James A. 01 January 1971 (has links) (PDF)
No description available.
56

Use of Ponds and Lakes by Resident Canada Geese

West, Phillip D. 01 January 2003 (has links) (PDF)
No description available.
57

Continual Energy Management Dynamics: Energy Efficiency in U.S. Automotive Manufacturing Industry

Onus, Cem O. 01 January 2011 (has links)
Managers at automotive manufacturers are seeking ways to reduce energy consumption, costs, carbon emissions, and waste from production processes. Researchers and practitioners perceive energy efficiency as the least expensive and most effective way to deal with issues related to climate change, but adoption of energy efficiency measures has been slow among industrial facilities. The topic of this research study was the decision-making process for energy efficiency projects in the U.S. automotive manufacturing industry. Flaws in this decision-making processes are preventing changes that can dramatically reduce energy usage, cost, and pollution. The study was grounded in the theories of energy management, organizational learning, systems thinking, and strategic management. Data is from open-ended question interviews and questionnaires of 21 decision makers in automotive manufacturing companies in the United States about their perception and experiences regarding the decision-making process for energy efficiency projects. The data were coded to identify themes. The findings indicated that organizational leaders with responsibility over energy management should include energy management standards and frameworks such as ISO 50001, Six Sigma DMAIC, and Energy Star as guidelines for selecting energy efficiency projects. Decision makers may find these results useful in improving their decision-making processes for evaluating energy efficiency projects. This research has the potential to promote positive social change in the automotive industry by reducing energy consumption and business costs, and it could benefit communities by reducing pollution through increasing energy efficiency in the automotive manufacturing industries.
58

Management By Crisis: Land Trust Conservation Engagement And Methods In Vermont

Lintilhac, Louise Sopher 01 January 2015 (has links)
Planning a future for the landscapes we live in can be a daunting challenge for many communities in Vermont. Conservation initiatives affect the quality of life for all community members and can be difficult if not impossible to change in the event of poor planning. Through examining stakeholder relationships with land trusts I have explored the complexities of planning processes used by land trusts in Vermont for conservation initiatives The study involved one statewide land trust, the Vermont Land Trust, and two community land trusts, the Stowe Land Trust and the Duxbury Land Trust. I used qualitative methods including document review, observation and interviews to gather data on land trust planning. My study shows how stakeholder relationships shape conservation initiatives, what strategies land trusts use to aid stakeholder involvement, and finally, how stakeholder input affects conservation easements and stewardship. Interviews with multiple internal and external stakeholders for the three land trusts indicate a negative feedback loop within the organizational structure of each land trust I call "management by crisis." My case study examples suggest that stakeholders do not get involved in conservation until there is a threat to the landscape. This makes strategic planning difficult and limits a land trust's ability to link important parcels together for environmental and social benefit. I suggest that management by crisis can be replaced with positive feedback using Community Based Participatory Research. This approach relies on communities initiating projects and being an integral part of the planning process from the beginning of a conservation initiative. By involving stakeholders from the conception of a conservation project, a land trust can better evaluate community needs in relation to social and environmental wellbeing.
59

Early Adoption Dynamics Of Private Sustainability Governance Initiatives: A Case Study Of The Marine Cultured-Pearl Industry

Nash, Julie 01 January 2015 (has links)
We are witnessing a time of unprecedented human impact on the natural environment. Coral reefs, one of the most biologically diverse and productive ecosystems, are at the forefront of enduring these human impacts. Despite widespread recognition of coral reef degradation, counter measures have not reached a scale to offset the threat. The magnitude of this and other environmental issues call for a deeper understanding of the role the private sector can play in sustainable development. In response to environmental pressures and the shortcomings of global-scale governance, private sustainability governance initiatives have developed. In the last decade, these initiatives have flourished, resulting in a diversity of formats including third-party certification, consumer product transparency systems, and industry roundtables. In many industries, these programs compete to define the transformation and evolution of sustainability governance in an industry. This dissertation draws on a case study of the marine cultured-pearl industry to highlight the early adoption dynamics of private sustainability governance initiatives. The marine cultured-pearl industry provides an illuminating case study for the adoption of private governance, based on the potential strength of the positive environmental impact and farm presence in ecologically vulnerable coral reef areas. Yet despite these strengths, no formal sustainability initiatives have developed. This research project explores the early adoption of private governance initiatives through a mixed-methodological, case-study approach. The first study, a quantitative survey of US jewelry consumers, examines the impacts of environmental messages on perceptions of luxury value. The second study assesses the effect of networked legitimacy on producer perceptions in private governance initiatives. The final study investigates the impact of value chain structure on competing private governance initiatives. The research results provide evidence of a strong business case for the development of industry-wide sustainability initiatives and highlights distinctions between the rival private governance initiatives. The US jewelry consumer research shows that consumer messages featuring sustainability standards to protect coral reefs outperform third-party certification on luxury attributes. The marine cultured-pearl producer research highlights the legitimacy advantages of consumer product transparency when compared to third-party certifications. The value chain research indicates that, when compared to third-party certifications, consumer product transparency systems have characteristics that provide an advantage in addressing producer upgrading opportunities. Results from each of the three studies highlight the potential advantages of consumer product transparency systems over third-party certification initiatives in this and other settings. These results helped inform participatory action research to assess alternative pathways for private sustainability governance.
60

Impacts of Transportation Infrastructure on Stormwater and Surface Waters in Chittenden County, Vermont, USA

Bartlett, Joseph Hollis 01 January 2016 (has links)
Transportation infrastructure is a major source of stormwater runoff that can alter hydrology and contribute significant loading of nutrients, sediment, and other pollutants to surface waters. These increased loads can contribute to impairment of streams in developed areas and ultimately to Lake Champlain. In this study we selected six watersheds that represent a range of road types (gravel and paved) and road densities (rural, suburban, and urban) present in Chittenden County, one of the most developed areas in Vermont. The location and density of road networks were characterized and quantified for each watershed using GIS analysis. Monitoring stations in each watershed were constructed and instrumented to measure discharge and water quality parameters continuously from spring through early winter. Storm event composite samples and monthly water chemistry grab samples were collected and analyzed for total nitrogen, total phosphorus, chloride, and total suspended sediments. Results from this study show that road type and road density are closely linked with the level of impairment in each watershed. Total phosphorus and total nitrogen from storm event composite samples and monthly grab samples significantly increased along a gradient of increasing road network density. Chloride concentrations increased several orders of magnitude along this same gradient. With the exception of Alder Brook where total suspended sediment (TSS) concentrations tended to be high, there were no significant differences in TSS concentrations between rural and developed watersheds. The elevated storm event TSS concentrations in the rural streams suggest that the unpaved roads in the rural watersheds contribute to stormwater runoff loads and that sediment control, at least in the developed watersheds, might be fairly effective. The overall results from this study show that local roads are a significant source of impairment for streams in the Chittenden County area. Most of these roads are municipal roads that are not under management of the Vermont Agency of Transportation. Thus, local actions will be necessary to reduce runoff and pollutant loading from these roads.

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