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Tesi sul tema "Fisheries management"
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1
Daw, Tim M. "How fishers count : engaging with fishers' knowledge in fisheries science and management /". Newcastle upon Tyne : University of Newcastle upon Tyne, 2008. http://hdl.handle.net/10443/114.
Testo completo
2
Daw, Timothy. "How fishers count : engaging with fishers' knowledge in fisheries science and management". Thesis, University of Newcastle Upon Tyne, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.490129.
Testo completoAbstract (sommario):
Engaging with fishers’ knowledge (FK) is increasingly valued in fisheries management (a) for FK’s utility for science and management, and (b) to improve the legitimacy of fisheries governance. Referring to both perspectives, this thesis examines: the nature and types of FK; FK’s relationship to scientific knowledge; and ‘extractive’ and ‘participative’ approaches taken to engage with FK. Chapters 3 and 4 compare fishers’ reports of catch rates with official landings data and underwater visual census (UVC). In Seychelles, contemporary reported catch rates and landings were consistent; but FK, landings and UVC perceived different trends over time. Over five western-Indian-Ocean countries, reported catch rates had no detectable relationship with UVC-measured fish biomass, despite a six-fold range in biomass. Such disparities between fishers’ and scientists’ perceptions provide opportunities to broaden the information base for monitoring; but challenge the legitimacy of science-based management in the eyes of resource users. Chapters 5 and 6 examine extractive approaches to engage FK. An interview-based stock assessment in Seychelles indicated that stocks were overexploited in contradiction to the qualitative perceptions of interviewed fishers. The extractive approach did not take account of fishers’ mental models which diverged from scientific assumptions about fish population dynamics and catch rates. In the North Sea, a postal questionnaire collected FK on stock trends, but had limited potential to influence scientific advice and satisfy fishers’ expectations, due to its limited scope T. Daw. How Fishers Count Page 3 and the lack of frameworks to utilise FK. Both cases illustrate the limitations of extractive methods, and the importance of engaging with more complex types of FK. Disagreements with science seem likelier, and more difficult to resolve for abstract types of FK. Extractive approaches can engage large numbers of fishers, but are less reliable and fail to improve governance. Participatory approaches, including collaborative research have greater promise for improving fisheries science and management.
3
Walshe, Kim A. R. "The fisheries' trinity : re-conceptualising New Zealand's inshore fisheries management /". Thesis, University of Auckland, 2010. http://hdl.handle.net/2292/5657.
Testo completoAbstract (sommario):
This thesis is the culmination of 35 years of fisheries management experience shaped by reflections and academic study. While New Zealand is often positioned as an acclaimed success with the development and application of the Quota Management System, this thesis outlines some of the serious flaws that underpin current trajectories. Tensions have been created by the Ministry of Fisheries focusing almost exclusively on developing solutions for New Zealand's fisheries policy and management problems through the commercial sector management regime. The 'command and control' management approach sits uneasily with the 'rights-based' management regime in the commercial fishery and the common property resource management regime in the customary Maori fishery.This study attempts to identify how the management of New Zealand inshore fisheries could be improved by using an integrated approach - a trinity of fisheries (institutions, rights, and governance) to manage all three sectors (commercial, recreational and customary Maori). The international literature provides a narrow view of fisheries policy and management in New Zealand and the discussion is strongly oriented around a limited range of issues - particularly commercial fisheries and a 'rights-based' approach. Drawing on a depth of experience in both central policy development and fisheries management (particularly in the Auckland Fisheries Management Area), four arguments are identified: Firstly, that New Zealand's fisheries management policies for both commercial and non-commercial fisheries management have been largely based on the commercial fishery. Secondly, that the international literature is heavily skewed towards issues and events in the commercial fishery without adequate recognition of the non-commercial (customary Maori and recreational) fisheries. Thirdly, that the three fisheries in the inshore waters cannot be managed effectively unless the management of all sectors is integrated under a common policy and management framework. And finally, that the 'rights-based' focus is faltering because of inadequate and inappropriate institutions and governance. The trajectories of the three inshore wild harvest sectors (commercial, recreational, and customary Maori) are explored, with a particular interest on how they influence and impact on each other. The primary focus of the analysis is the role that institutions, rights and governance play on the management and development of the three sectors. The thesis concludes with a chapter on the current positioning of institutions, rights, and governance within a three-sector trajectory and suggests tentative principles which could be used in New Zealand's inshore wild stock fisheries to build an integrated policy and management. It concludes that New Zealand's inshore fishery requires a re-conceptualisation to a governance approach, based on ecosystem management. A common management approach across all sectors of fisheries can be achieved by incorporating a wider institutional framework than a rights-based approach and moving beyond a focus on harvesting alone.
4
Cahill, Paul C. "The economics of fisheries and fisheries management : a partial review". Thesis, McGill University, 1985. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=63301.
Testo completo
5
Salas, Silvia. "Fishing strategies of small-scale fishers and their implications for fisheries management". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0020/NQ56612.pdf.
Testo completo
6
Salas, S. "Fishing strategies of small-scale fishers and their implications for fisheries management". online access from ProQuest databases online access from Digital Dissertation Consortium access full-text, 2000. http://libweb.cityu.edu.hk/cgi-bin/er/db/pqdiss.pl?NQ56612.
Testo completo
7
Almeida, Oriana Trindade de. "Fisheries management in the Brazilian Amazon". Thesis, Imperial College London, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.415981.
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8
Cunningham, S. "Fisheries management within the enlarged EEC". Thesis, University of Portsmouth, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372077.
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9
Mangi, Stephen C. "Gear management in Kenya's coastal fisheries". Thesis, University of York, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.428447.
Testo completo
10
Papaioannou, Maria Andriana. "Fisheries management and flags of convenience". Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/33432.
Testo completoAbstract (sommario):
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 2004.Page 123 blank.
Includes bibliographical references (p. 105-107).
The over-exploitation of the world's fish resources and the depletion of many fish stocks have brought into focus the need for effective fisheries management and conservation measures. Many states have adopted international instruments or have participated in regional conservation committees to regulate and control fishing activities within their jurisdiction as well as on the high seas. However, compliance with the provisions of the fishery laws has been limited and as fishing restrictions increase, more incidents of illegal, unregulated and unreported (IUU) fishing activities are being reported. IUU fishing is facilitated by the use of flags of convenience (FOC), which enable fishing vessel owners to escape regulations, and often avoid liability for their actions. Many measures have been introduced and many existing laws have been reinforced to address the implications of FOCs in effective fisheries management. However, the FOC fishing fleet continues to increase, indicating that there are flaws in the current regulatory scheme. The objective of this thesis is to identify those flaws by examining both the conservation regime for fisheries as well as the role of FOCs in the world's fish trade, rather than focusing solely on their negative impact.
(cont.) By studying the rationale for the decisions of all participants in the fishing industry, from lawmakers, to major traders, we conclude that increasing transparency and flag state responsibility, although necessary, will not eliminate IUU fishing. FOCs are not the driving force for illegal fishing; on the contrary, they are the means to serve the purpose, which in this case is the satisfaction of high demand for high-valued scarce fishery resources.
by Maria Andriana Papaioannou.
S.M.
11
Karagiannakos, Apostolos. "Fisheries management in the European Communities". Thesis, University of Aberdeen, 1994. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU060624.
Testo completoAbstract (sommario):
In 1971, the European Communities introduced a Common Fisheries Policy (CFP), which was more fully developed in 1983. Its success remains largely questionable because it has failed to conserve fish stocks, has been unable to tackle the problem of vessel overcapacity or to generate rents from the fishery resource. This thesis presents an overview of the main components of the CFP and assesses their impact on different aspects of the fishing industry. The economic and biological knowledge on which the fisheries management is based has been evaluated and a management scheme for reforming the CFP is proposed. The thesis initially surveys the literatures in fisheries economics and in fish population dynamics. These should provide the basis for efficient management, and their role is evaluated. European Community institutions and the procedures which are involved in the policy formation are examined. Particular attention is paid to the evolution of the legislative framework of the Common Fisheries Policy from its establishment to the latest developments. The work evaluates the main constituent parts of the CFP, whose objectives are the rational development of the production factors, a fair standard of living for the producers, a stable market and the availability of supplies for consumers. The main conclusions reached are that the policy has been consistent with a decline in fish stocks, an increase in vessel capacity, a failure to stabilise market prices and a decline in the average fisherman's income. These outcomes can be attributed largely to an inadequate policy framework, which ignores the main conclusions of fisheries economics, and to an inadequate system of information gathering and of policing the regulations.
12
Dimech, Mark. "Conservation of the demersal fisheries resources within 25NM Maltese fisheries management zone". Thesis, Bangor University, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.496140.
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13
Nguyen, Quang Van. "Impacts of fisheries management objective on technical efficiency: Case studies in fisheries". Thesis, Queensland University of Technology, 2019. https://eprints.qut.edu.au/131191/1/Quang_Nguyen_Thesis.pdf.
Testo completoAbstract (sommario):
This dissertation is the first to examine the impact of differing fisheries management objectives and potential trade-offs with respect to technical efficiency. Understanding this relationship is important, as fisheries managed with strong social objectives, such as maintaining livelihoods, may, potentially trap individuals in inefficient, low-income production systems. The key conclusions were that fisheries managed with strong economic objectives resulted in higher technical efficiency than those with social objectives. However, other factors (including efficiency estimation methods used, model specifications, input measures) also have an impact on technical efficiency levels. Hence, technical efficiency estimates between fisheries should be compared with caution.
14
Kaye, Stuart B. "International fisheries management, a comparative analysis of legal approaches to management in the context of polar fisheries regimes". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape9/PQDD_0020/NQ49269.pdf.
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15
Hutton, Trevor Patrick. "Fisheries management policy in South Africa : an evaluation of alternative management strategies for the Hake and Linefish fisheries". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0020/NQ56561.pdf.
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16
Al-Mukhaini, Hilal Mohamed. "Fisheries management in Oman : the relevance of local community participation in fisheries management in Sur, the Eastern region". Thesis, University of Portsmouth, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.415376.
Testo completo
17
Locke, Diana. "Oyster fisheries management of Maryland's Chesapeake Bay". ScholarWorks, 1998. http://scholarworks.waldenu.edu/dilley/7.
Testo completoAbstract (sommario):
This study examines the concept of property rights in relation to fisheries resource management in the Maryland oyster fishery. An analysis of the past and present state of this fishery on the Chesapeake Bay focused on the administrative, biological, social, economic, and political influences in fisheries management and their potential consequences. This single fishery once provided a quarter of America's oysters but, if the oyster population decline continues, it may soon become a memory. Though Maryland has a dual property rights structure, private and public, the public fishery predominates. The reasons why privatization has not been a successfully implemented strategy, and whether the Maryland fishery embodies a unique situation better served by other management strategies, were addressed, and community-based alternatives from other types of fisheries were evaluated for their efficacy and applicability to Maryland. Historical and current information on Chesapeake oyster populations, events contributing to population fluctuations, and changes in fisheries management strategies were examined for any causal trends and compared and contrasted with other fisheries. The study found that culture and job satisfaction prevents privatization from becoming an accepted property rights management strategy in Maryland. This study also illustrates how cooperative fisheries management strategies can address nonmonetary benefits, traditional values, and coastal community structures, while achieving a sustainable harvest, preserving a traditional way of life, and restoring habitat and the oyster's role in the Bay's ecology. Any changes in the future will likely be directed toward changing the rules of management and harvest for the public grounds. If oyster production is to be increased in the Chesapeake Bay, the cooperation, consent, and responsibility of the watermen are needed for any policy to be successfully implemented. The future of fisheries management will not and cannot be confined to fisheries biology and population counts. It will need to encompass a broad arena of disciplines working together toward a common goal.
18
Needle, Coby L. "Fleet dynamics in fisheries management strategy evaluations". Thesis, University of Strathclyde, 2011. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=18939.
Testo completo
19
Johnston, Fiona Dawn. "Towards the sustainable management of recreational fisheries". Doctoral thesis, Humboldt-Universität zu Berlin, Lebenswissenschaftliche Fakultät, 2015. http://dx.doi.org/10.18452/17183.
Testo completoAbstract (sommario):
Die Freizeit- bzw. Angelfischerei ist ein komplexes sozial-ökologisches System, welches sich aus drei wesentlichen Komponenten zusammensetzt: einer biologischen, einer sozialen und einer Managementkomponente. Fischereimanager sind aufgefordert, anglerischen Interessen und den Anforderungen einer biologisch nachhaltigen Gewässerbewirtschaftung gleichsam gerecht zu werden. Unzureichend verstandene Wechselwirkungen zwischen den Fischereikomponenten limitieren die Möglichkeit, die Angelfischerei nachhaltig zu entwickeln. Diese werden beeinflusst von lebensgeschichtlichen Parametern der jeweiligen Fischart, von Dynamik und Diversität der Angler sowie von Maßnahmen und Managementzielen. Die Dissertation untersuchte die Bedeutung einer gleichzeitigen Berücksichtigung der drei Fischereikomponenten und ihren Wechselwirkungen zur Realisierung einer biologisch und sozial nachhaltigen Angelfischerei. Ein neuartiges bioökonomisches Simulationsmodell identifizierte Bewirtschaftungsmaßnahmen, die den von der Fischerei erzeugten sozialen Nutzen maximieren. Die Ergebnisse widerlegen die Annahme der Selbstregulationsfähigkeit der Angelfischerei. Die Höhe und Art der Befischungsintensität sowie der soziale Nutzen wurden stark durch eine Vielzahl von fangabhängigen und fangunabhängigen Attributen beeinflusst, wobei auch Anglertyp und Anfälligkeit der Fischpopulation zur Überfischung eine Rolle spielten. Einige Regularien zur Erreichung der Bewirtschaftungsziele waren effektiver als andere, aber ihre Wirksamkeit könnte durch die Haksterblichkeit und die Nichteinhaltung von Vorschriften unterlaufen werden. Obwohl sich die Bewirtschaftungsmaßnahmen je nach Zielart, Anglerschaft und Bewirtschaftungszielen richten, beinhalten die als optimal identifizierten Maßnahmen in fast allen Fällen eine biologische nachhaltige Bewirtschaftung. Die Ergebnisse zeigen, dass ein interdisziplinärer Ansatz zu einer sozial und biologisch nachhaltigen Bewirtschaftung der Freizeitfischerei beitragen kann.Recreational fisheries are complex social-ecological systems, and managers often need to balance the interests of the anglers utilizing the fishery – the social sustainability – and the biological sustainability of the fish population. However, a poor understanding of the interactions among the main components of a fishery – the biological, social, and management components – has limited our ability to manage recreational fisheries sustainably. Fish life-history type (LHT), the dynamics and diversity of the angler population, angling regulations and management objectives all influence management outcomes. Using both empirical and theoretical studies, I evaluated the importance of jointly considering these primary drivers and the feedbacks between fishery components when managing recreational fisheries. I developed a novel bioeconomic modelling framework to determine which regulations (effort regulations and minimum-size limits) maximized the social welfare derived from the fishery, the optimal social yield (OSY). My research refutes the hypothesis that anglers are self-regulating (i.e., stop fishing when catch rates decline). The amount and type of fishing pressure the fishery received and the social welfare derived were strongly influenced by multiple fishery attributes and differed with the type of angler fishing and the fish population’s vulnerability to overexploitation (LHT). I found regulations influenced fishing mortality rates, but also directly influenced angler behaviour. Some regulations were more effective than others at achieving management objectives, but their effectiveness could be undermined by hooking mortality and regulatory noncompliance. Despite differences in optimal regulations, an OSY management approach generally did not result in overfishing. My research demonstrates that a multidisciplinary approach based on clear objectives can help us progress towards both socially and biologically sustainable management of recreational fisheries.
20
Strehlow, Harry Vincent. "Integrated natural resources management of coastal fisheries". Doctoral thesis, Humboldt-Universität zu Berlin, Landwirtschaftlich-Gärtnerische Fakultät, 2006. http://dx.doi.org/10.18452/15573.
Testo completoAbstract (sommario):
Das Untersuchungsgebiet, die Nha Phu Lagune, weist eine massive Degradation der fischereilichen Ressourcen auf. Die „Rural Livelihoods“ in den Gemeinden dieser Küstenregionen sind durch diese Degradation gefährdet. Da, die Ressourcennutzungsentscheidungen einzelner Haushalte von vielen Faktoren abhängen, bedarf es eines multi-sektoralen Forschungsansatzes. Dieser ermöglicht, die Komplexität und die Diversität des Ressourcennutzungssystems und seine Nutzer, zu erfassen. Das Integrated Natural Resources Management (INRM) ist ein multi-sektoraler Forschungsansatz, der innovative und flexible Managementformen zu entwickeln versucht, um natürliche Ressourcen nachhaltig zu nutzen. Interdisziplinarität und die Betonung von Partizipation sind zentrale Kennzeichen des angewandten INRM-Forschungsansatzes. Diese interdisziplinäre Vorgehensweise berücksichtigt sowohl sozio-ökonomische und institutionelle Einflussfaktoren, z.B. Ressourcennutzer-Gruppen und bestehende Regulierungen und Gesetze, als auch biologische und produktionstechnische Einflussfaktoren, z.B. Aquakultur und Fischfangtechniken. Während eines sechs monatigen Untersuchungszeitraums unter Anwendung Partizipativer Aktionsforschung und des INRM-Ansatzes wurden 12 Dörfer im Umkreis der Nha Phu Lagune besucht. Der innerhalb der Partizipativen Aktionsforschung angesiedelte Lernzyklus generiert Wissen durch die Reflektion von gesammelten Daten, die kontinuierlich an die Beteiligten zurückgeführt werden. Die Erhebung mittels Fragebögen, halbstrukturierter Interviews, Gruppendiskussionen, Observierung, „Resource Mapping“ und Venn Diagrammen identifizierte Ursachen für die Degradation fischereilicher Ressourcen. Diese Informationen wurden dann an die Beteiligten weitergereicht, was zu neuen Erkenntnissen über alternative Ressourcenmanagementstrategien führte. Die Integration biologischer und sozio-ökonomischer Aspekte erfasste die Komplexität des Ressourcensystems Nha Phu Lagune und seiner Nutzer. Dies beinhaltet eine Vielzahl von verschiedenen Ressourcen, Akteuren, Ebenen, Institutionen, Entscheidungsstrukturen, Livelihood Strategien, Trends und assoziierte Probleme des nachhaltigen Managements natürlicher Ressourcen.The selected study site, Nha Phu Lagoon is characterized by massive degradation of coastal fishery resources. As a result rural livelihoods in coastal communities are threatened. Since household decisions concerning resource use are influenced by several factors, a multi-sectoral approach is necessary. A multi-sectoral approach enables to comprehend the complexity and diversity of the resource system and its users. Integrated natural resources management (INRM) is one multi-sectoral research approach that aims to develop innovative and flexible management forms to manage natural resources in a more sustainable way. The applied INRM-approach is characterized through strong interdisciplinarity and participation. Interdisciplinary means that socioeconomic and institutional aspects, e.g. resource-user groups and existing legal arrangements, are combined with biological as well as production system aspects, e.g. mangrove reforestation as well as aquaculture or gear-fishing techniques. For a period of six months participatory action research following an integrated natural resource management approach was carried out visiting 12 fishing villages around Nha Phu Lagoon. The inherent ‘learning cycle’ in participatory action research generates knowledge in a process of reflecting on the collected data that is continuously fed back to the participants. During questionnaires, semi-structured interviews, group discussions, observations, resource mappings, and Venn diagrams reasons for the degradation of fishery resources were gathered. This information was then shared with participants, which led to new insights as well as alternative resource management strategies. The integration of biological and socioeconomic aspects identified the complexity of the coastal fishery resource system Nha Phu Lagoon and its users. This includes a multitude of different resources, actors, levels, institutions, decision-making structures, livelihood strategies, trends, and associated problems in the sustainable management of the natural resources.
21
Geromont, Helena Francine. "Effective fisheries management with few data: A management procedure approach". Doctoral thesis, University of Cape Town, 2014. http://hdl.handle.net/11427/8699.
Testo completoAbstract (sommario):
Includes bibliographical references.Complex stock assessments which typically rely on a comprehensive set of age or length data are traditionally seen as an essential requirement for sound fisheries management. An alternative process less commonly adopted for the provision of reliable on-going management advice is called the Management Procedure (MP) approach. This approach is pro-active and strategic rather than reactive and tactical, and lends itself well to forecasting and long-term fisheries management. This thesis investigates the application of the MP approach to data-poor as well as data-rich stocks. The majority of fish stocks worldwide are not managed using quantitative analysis as there are not sufficient data on which to base a resource assessment. Often these stocks are relatively "low-value", which renders dedicated scientific management too costly, and a generic approach applicable across a range of stocks is therefore desirable. The aim of the first line of analysis in this thesis is to illustrate the design and testing of some very simple "off-the-shelf" management procedures (MPs) that could be applied to groups of data-poor stocks which share similar key characteristics in terms of demographic parameters. For this initial investigation, a selection of empirical MPs is simulation tested over a wide range of Bayes-like operating models (OMs) representing the underlying dynamics of resources classified as "depleted", in order to ascertain how well these different MPs perform. The moderately data-poor MPs (based on an index of abundance such as provided by a survey or reliable CPUE) perform somewhat better than the extremely data-poor ones (based on the mean length of catch data) as would be expected. Nevertheless the very data-poor MPs perform surprisingly well across the wide range of uncertainty considered for key parameters. The second line of analysis in this thesis focuses on high-value data-rich marine resources: which of the two management paradigms is more suitable where sufficient data for annual stock assessments are readily available? This question is addressed through a retrospective study of management performance over the last twenty years for four North Atlantic fish stocks. The actual assessment advice for these stocks was provided on the basis of complex assessment methods making use of age data. The outcomes are compared to what could have been achieved with much simpler MPs based upon age-aggregated survey indices alone. Even for some of these stocks whose assessments exhibit retrospective patterns, these MPs can achieve virtually equivalent catch and risk performance, with much less inter-annual TAC variability, compared to what actually occurred over the past twenty years. Despite the simplicity of the harvest control rules simulation tested in this thesis, these MPs could well provide the basis to develop generic MPs to manage data-poor stocks, ensuring if not optimal, at least relatively stable sustainable future catches. Moreover, these initial results suggest that simple empirical MPs could provide a defensible, simpler and less costly alternative approach to the provision of scientific management advice for high-value data-rich resources. The advantages of adopting a procedural paradigm for fisheries management purposes are highlighted and rationale is offered as to why it may be prudent (better aligned with the precautionary approach) to adopt an MP approach, even in circumstances where reliable data, expertise and financial support are readily available to perform annual assessments.
22
Folkesson, Malin. "Towards a Sustainable Fisheries Management : How to address uncertainty in order to achieve a sustainable development of regional fisheries management". Thesis, Stockholms universitet, Institutionen för naturgeografi och kvartärgeologi (INK), 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-55099.
Testo completoAbstract (sommario):
Fisheries management is not only about managing the resource fish, but also includes managing the social system. Aquatic ecosystems and the social system are both complex and change continuously. It is important to address what types of uncertainty the combination of both systems, complex socio-ecological systems leads to, their consequences and how these should be dealt with. Successful or unsuccessful management outcomes are difficult to address whether or not they are due to management efforts or natural changes. In addition, uncertainties often lead to a short-term management, since lack of knowledge makes it difficult to act in a long-term perspective. This thesis conceptualizes how to address different types of uncertainty prevalent in fisheries management, with focus on natural process uncertainty, measurement and estimation uncertainty, decision and implementation uncertainty, and institutional and regime uncertainty. This was done by analyzing how three theoretical approaches, namely co-management, adaptive management and adaptive co-management address these uncertainties. In order to highlight how different types of uncertainty have been dealt with in practice, a case study on the fishery management in Lake Vättern has been made. A comparison between the literature study and this thesis’ case study shows that hypothesis-testing, cooperation, communication and transparency are corresponding factors on how to deal with uncertainties in fisheries management and that institutional and regime uncertainty is inadequately addressed in Sweden.
23
Alam, Mohammed Khurshid. "The constraints of fisheries management in Punjab (Pakistan)". Diss., The University of Arizona, 1991. http://hdl.handle.net/10150/185674.
Testo completoAbstract (sommario):
Acute and chronic toxicity tests for malathion, diazinon, and sherpa and for Cu, Hg, Pb, Zn, Ni, and Fe were conducted. Mortalities and LC50-96 hr values for Barilius vagra and Cyprinus carpio exposed to pesticides were variable. Long-term exposure to pesticides modified morphology and behaviour. The LC50-96 hr values for Cu, Hg, Pb, Zn, Ni, and Fe were low for small fish. Selected metal residues were significantly greater in whole juvenile carp following exposure to sublethal concentrations. Water samples from selected industrial drainages and receiving streams showed abnormal pH and oxygen levels. Selected metals (Fe, Pb, Zn, Cd, Cu, Ni, Hg) were higher in all effluents. Static bioassays of the undiluted industrial effluents from three sites caused 100% mortality in carp during the first 24 hrs and some mortality when effluents were diluted by 50%. A mesh size vulnerability model using the girth retention function for the Mangla Lake Fishery was developed. The impact of variable mesh size on fish harvest was evaluated. Probability of encountering the net was proportional to the distance travelled by fish, and a corrected size distribution improved the use of the model. Harvest of a surplus of large fish could be achieved by: (1) increasing the number of commercial nets in the 65-105 mm mesh size and (2) using a broader range of mesh sizes. Controlling fishing intensity and mesh size regulation over time would provide feedback for subsequent management decisions. Dynamic changes in the population, permissible harvest, number of fingerlings stocked and maintenance of year classes would allow the development of a better management model. Three supplementary feeds from inexpensive ingredients were developed and their relative ability to increase the growth of three indigenous carp (Catla catla, Labeo rohita, and Cirrhinus mrigala) and two exotic carp (Cyprinus carpio and Hypophthalmichthys molitrix) were compared. The growth of indigenous carp was low on all three feeds. All species of fish grew best on feed three. Information is needed on the ecological niches and nutrient requirements of the native carps.
24
Greenville, Jared William. "Marine Protected Areas: A Tool for Fisheries Management". Thesis, The University of Sydney, 2007. http://hdl.handle.net/2123/1893.
Testo completoAbstract (sommario):
The management of fisheries has progressed over the past century in an attempt to solve the problem of open access. A range of controls, both economic and non-economic in nature, have been used to ration the use of marine resources. Unfortunately, many controls have failed to correct open access problems. Whilst a recent development in fishery control, protected areas defined as an area with a fishery free of extractive pressure, have been put forward as an arrangement which may, in conjunction with other controls, be used to overcome the over-exploitation of marine resources. Marine protected areas have been advocated in areas where other forms of fishery management are impractical or unsuccessful (Sumaila 1998). Arguments for protected area use are based around the heterogeneous nature of fisheries, uncertainties in marine populations and as a hedge strategy to reduce risks of over-exploitation (Conrad 1999a). Through the protection of biodiversity, improving the resilience of the ecosystem, protected areas may mitigate the effects of negative shocks (Ludwig et al. 1993 and Bostford et al. 1997). Further, protected areas have been suggested as a means to manage uncertainty and environmental stochasticity (Grafton and Kompas 2005 and Grafton et al. 2005). The protection of biomass and habitat has the potential to improve fishery returns even when stocks are not overly exploited, with the benefits accruing even from small-sized protected areas (Grafton et al. 2005). The use of marine protected areas as a management tool has resulted from a recognition that it is important to preserve biological habitats as well as stocks. From a societal point of view, the use of protected areas should be evaluated in the context of changes in resource rent and improvements in welfare. As fishery resources are often owned by a common group, usually society, management objectives should be to maximise the return from use of the resources, whether for extractive or non-extractive purposes. Given this decision criterion, protected areas can be evaluated in the sense of opportunity costs and benefits. Protected areas will influence the return from fishery resources through changes in access to fishing grounds, and thus harvest, effort and resource rent. Once a protected area is established, the flow of biomass from the protected area to the remaining fishing ground, may increase biomass, influence the effects of uncertainty and stochasticity, thus effecting mean harvests, effort and resource rent may increase. Changes in resource rent are dependent on other controls. Protected areas are a ‘blunt’ policy instrument, in the sense that they are not an instrument to capture resource rent or change the incentives of fishers. Models of marine protected areas in fisheries vary in complexity, however, a few key elements are necessary in analysing the effects of protected area creation. First, multi-species interactions have the potential to be significant in determining the outcome from a protected area; second, effort expended in the fishery must be dynamic, that is, it must be endogenously determined by the model as fishers will respond to changes in rent brought about through the establishment of a protected area; third, institutional structures that govern the expenditure of effort within a fishery will play an important role in the effectiveness of protected areas in increasing the resource rent of a fishery; and fourth, environmental stochasticity and uncertainty need to be included in the analysis. A stochastic and deterministic model of a predator-prey meta-population fishery was developed to analyse the effects of protected area creation within a fishery. Such a model has not previously been used to analyse protected area creation. The model was analytically solved to find the optimal biomass of each species in an individual patch. This allowed for a comparison of protected areas under a range of management controls ranging from those which led to open access fishing to those which led to an optimal steady-state biomass. The model allowed for linkages between sub-populations based on differing density related flows. Further, due to the linkages between species on both environmental and economic grounds, the effect of protected areas on different groups which target different species could be analysed. The benefits from protected area creation were classified into unique and non-unique benefits. Unique benefits were defined as those which solely flow from the use of a protected area as a tool in fisheries management. Two unique benefits were defined: • Improvements in the resilience of the fishery; and • Reductions in environmental stochasticity. The ability of a protected area to both improve the resilience of the fishery, and smooth fluctuations in environmental stochasticity have been shown to lead to increases in mean resource rent. Thus, protected areas were shown to form part of an optimal fisheries management structure. Generally, the resilience benefits were maximised for small-sized protected areas, whereas the reduced environmental stochasticity benefits were maximised for larger protected areas. The dispersal system between the protected area and the fishing ground affected the unique benefits from protected area creation. Sink-source dispersal increased the unique benefits from protected area creation, as stock movements occurred independently of relative population densities. The independent flow improved the ability of the protected area to hasten the return of the fishery to a steady-state and lessened the variation of harvests in the open fishing grounds. However, in the case where the protected area led to large differences in population densities, and if the area formed a sub-population that was linked to the surrounding fishing ground by density-dependent dispersal, the unique benefits are likely to be greater than under sink-source dispersal. The non-unique benefits were defined as those which could be obtained from other control mechanisms. These benefits were non-unique as they could be achieved from more stringent controls on fisher behaviour. The determinants of the non-unique benefit in terms of dispersal were the same as for the unique benefits. However, the economic conditions of the fishery determined the magnitude of the non-unique benefits. For fisheries with sub-optimal biomass, the unique benefits were greater than those with optimal steady-state biomass. The non-unique benefits identified from protected area creation were: • Changes in biomass towards optimal levels; • Changes in species biomass ratios towards optimal levels; and • Changes in effort towards optimal levels. Protected areas in fisheries may be an optimal policy choice to achieve the non-unique benefits of protected area creation. Protected areas, it has been argued, are a relatively low cost management tool, due to the lower monitoring and enforcement costs. Thus, the use of protected areas offer a solution to the problems of over extraction of fishery resources for lower transaction costs, which may erode the non-unique benefits under different policy instruments. If this is the case, then a protected area larger than is required to maximise the unique benefits of protected area creation could form part of an optimal fisheries management strategy. Whether the protected area is larger or smaller than the size that maximises both the unique and non-unique benefits of protected area creation would depend on the level of transaction costs involved in using alternative policy instruments. Protected areas were found to have distributional effects on the fishery due to changes in the species biomass ratio towards the predator species post protected area creation. The creation of a protected area will have distributional effects on the fishing industry if different fisheries target the different species separately. Fishers targeting predator species are likely to gain from the establishment of a protected area, as now the aggregate level of stocks of this species is greater, leading to both greater unique and non-unique benefits. For fisheries that target prey species, the benefits of protected area creation are lessened. The increased predation within protected area boundaries limited the unique benefits of the protected area. The low cost nature of a protected area will influence the portion of the fishery used for this type of control given an optimal policy programme. If protected areas are relatively low cost in comparison with other controls they should be used relatively more intensely. Further, the use of protected areas may hasten the evolution of fisheries away from open access exploitation towards controls which maximise the value of the fishery. With lower transaction costs, the ability to adopt protected areas over other forms of management is greater, and by doing so, the movement towards optimal exploitation will improve the discounted value of the fishery. The analysis presented in this thesis examined the benefits of protected areas to fisheries. The focus of the study was placed on the benefits to flow to a fishery if a protected area was used as a tool for wild-harvest fisheries management. Marine protected areas also have the potential to generate a range of other benefits, such as recreational values, non-use values, and potential improvements in consumer surplus from fish caught within fisheries that use protected areas. These other benefits would need to be considered when determining whether or not a protected area should be created in a fishery.
25
Albrecht, Daniel E. (Daniel Edward). "Co-management as transaction : the Kuskokwim River Salmon Management Working Group". Thesis, McGill University, 1990. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=59815.
Testo completoAbstract (sommario):
This thesis focuses on transactional process involved in the construction and operation of the Kuskokwim River Salmon Management Working Group. This cooperative wildlife management mechanism gives Yup'ik commercial and subsistence fishermen and other users a direct role, with the Alaska Department of Fish and Game, in salmon management.Transactions involving participants' knowledge and values are described in three processes: (1) the establishment of a management body and its operating rules; (2) the mediation of power in decision-making; and, (3) fishery management which uses both "science" and "fishermen's knowledge."
Results indicate that through cooperation in decision-making, data gathering, and other management tasks the participants have been able to promote record commercial salmon harvests while at the same time providing for subsistence and conservation needs. Shared local values of consensus and reciprocity have acted to sustain participants' interaction in the bargaining process inherent in co-management. Through having to mediate and accommodate diverse interests and goals, the participants have developed a significant congruency or compatibility of values.
26
Brennan, William J. "Overcoming Transaction Cost Impediments to Resolving the Dilemma of Collective Action in the New England Fisheries". Fogler Library, University of Maine, 2002. http://www.library.umaine.edu/theses/pdf/BrennanWJ2002.pdf.
Testo completo
27
Dawson, Robert Donald. "Vertical Integration in Commercial Fisheries". Diss., Virginia Tech, 2003. http://hdl.handle.net/10919/28627.
Testo completoAbstract (sommario):
Vertical integration has received much attention in the last 25 years and there are well-known theories that explain this behavior. However, the one common thread that runs through virtually all of this research is the assumption of private property rights. Very little attention has been paid to how firms behave when the property rights structure under which they operate changes. The commercial fishing industry is a prime example of an industry where property rights have shifted. Due to problems of over-fishing and over-capitalization, economists have championed the conversion of fisheries from common property or open access resources, to private property through the use of quota programs.
Research shows that quota management is effective in reducing capitalization in fisheries, yet there are questions about other effects the programs might have. Among these is a concern over increased vertical integration. Some argue that this is leading to a loss of the independent fisherman that is a part of U.S. history, much like family farms. There is also concern that increased vertical integration is in turn leading to decreased competition in these markets; by owning the quota that is required to fish, processors are increasing their power over the market for unprocessed fish. In response to these and other concerns, the United States Congress imposed a moratorium on the implementation of individual transferable quota-style (ITQ) programs in 1996. Speculation aside, however, there is no empirical evidence to confirm or refute that the use of quota management actually leads to increased vertical coordination.
Three fisheries are used as case studies to analyze what affects the decision to vertically coordinate in commercial fisheries. The traditional reasons for vertical integration are to lower transaction costs or to foreclose a market. But now a new factor, shifting property rights, is also considered. Results indicate that the individual characteristics of the fishery are more important than the management or property rights regime itself. This gives some direction to designing management programs that meet our desire to reduce over-capitalization and over-fishing, yet avoid increasing vertical coordination, all the while minimizing the loss of resource rent in the fishery.Ph. D.
28
Alakhzami, Younis. "Spatial data integration for marine fisheries management of Oman". Thesis, University of Leicester, 2000. http://hdl.handle.net/2381/30385.
Testo completoAbstract (sommario):
The work described in this research uses the commercial data of catch to illustrate the facilities that GIS may offer to fisheries management. Three different types of fisheries data (different in terms of original format, method of collection and geographical footprints) for Oman are presented and discussed. Data collection, manipulation, filtering and preparation for input to a relational database are discussed. The spatial integration of the data is problematic but essential. Two methods of data integration, the point and the area are used to solve this problem. Point and area data are used to display data at different levels of management and decision making. Alternative visualisations from the GIS are used including total catch distribution, catch per unit effort per unit area, fishing density, and spatio-temporal analysis. The analytical ability of the GIS is used to display the following results: preferred areas of catch, expected catch per area, areas of fish high quality habitat, unexploited areas, and areas suspected of overfishing. Hydro-biological data (marine-related data) such as sea surface temperature, dissolved oxygen, salinity, and zooplankton biomass for the year 1995 with relation to catch are presented and discussed too. The concentration of catch is found to be more within the area of the continental shelf that in the deep waters, being areas of large fish productivity as well as high zooplankton biomass. Pelagic fish occur in greater density in the northern part of the Omani waters (Gulf of Oman), and in contrast, demersal fish aggregated more at the southern part of the country (Arabian Sea). Different areas are found to have a consistently high catch throughout the years, and the catch, in general, shows no evidence of overfishing. Some areas of Omani water have not been fully utilised although this study shows them high potential catch areas.
29
Paylor, Adrienne D. "Community-based fisheries management and monitoring development and evaluation". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ32946.pdf.
Testo completo
30
Wiium, Vilhjálmur Hansson. "Discarding of fish and fisheries management, an economic perspective". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ61695.pdf.
Testo completo
31
Bailey, Megan Lynn. "Improving the management of global and regional tuna fisheries". Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/42825.
Testo completoAbstract (sommario):
Tuna can travel thousands of kilometers throughout their lifetime, and are often found in the waters of several nations and the high seas. These ``straddling stocks" are difficult to manage due to competition between the large number of interested fishing nations, all of which can be asymmetric in their economies, management capacity and conservation concerns. This is compounded by the possibility of new members and free riders. It is no surprise then, that tuna fisheries management has, by and large, been unsuccessful in promoting sustainable fisheries. Populations of several of the world's tuna species are fully or over-exploited. This dissertation identifies and addresses areas where improvements in the management of global and regional tuna fisheries may facilitate the continued contribution of these fisheries to livelihoods and food security.
I analyze private and social resource rent derived from fishing for different tuna species and by different gear types. From these results I identify key management targets. Management efforts are formalized through Regional Fisheries Management Organizations (RFMOs), groups which are mandated to promote cooperative agreements and fair and equitable allocation approaches. Stable cooperative agreements, however, have been hard to come by for tuna RFMOs, in part because the issue of allocations has not been appropriately targeted. I propose a combined socio-economic and ecological approach formulated from the perspective of fisheries benefits, as opposed to just catch, which could facilitate stable cooperative agreements for sustaining tuna stocks into the distant future.
Tuna fisheries in the western and central Pacific provide over half of the world's tuna, but lack of effective management capacity in Indonesia and the Philippines threatens the sustainability of these fisheries. I argue that countries that fish in this region, most specifically Papua New Guinea, would be wise to help facilitate improved management capacity in these countries. One of the major management challenges in this region is the bycatch of juvenile yellowfin and bigeye tuna in the skipjack purse seine fishery. Through applied game-theoretic modelling, I conclude that reduction in juvenile bycatch brought about by cooperative management of these fisheries would provide long-term ecological and economic benefits.
32
Willby, Nigel John. "Management of navigable canals for nature conservation and fisheries". Thesis, University of Liverpool, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240821.
Testo completo
33
Gonçalves, Leandra Regina. "Regional Fisheries Management Organizations: is power listening to Science?" Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/101/101131/tde-21112016-164951/.
Testo completoAbstract (sommario):
One of the biggest challenges in contemporary global environmental governance is the future of marine biodiversity. Over the years, increased fishing efforts in previously remote areas drove many fish stocks to scarcity. The Regional Fisheries Management Organizations (RFMOs) emerged to solve the international fishery crisis, on the assumption that they would provide a forum where Member States may agree and discuss binding rules for the conservation and management of fish stocks within its geographical area of responsibility. Although some agreements existed for more than 60 years, many authors agree that they have not been fully effective in promoting the maintenance and conservation of fish stocks. There are many reasons that might explain the lack of effectiveness, one of them being that science is not very often listened to in the political decision-making process. In this research, the influence of knowledge and science in shaping policy decisions will be observed and analyzed. Therefore, the use of the epistemic communities theory, that which forms part of the constructivist turn in international relations -- was used to answer the main question posed here: when does power listen to science? When it does, does it bring more effectiveness in terms of knowledge, input from epistemic communities, does it induce states to change their behavior, and do these influences lead to policies, which can credibly improve biomass? Using process tracing, through elite interviews, and with a systematic compilation and study of meeting reports from three RFMOs: the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR); the International Convention for the Conservation of Atlantic Tunas (ICCAT); and the Commission for the Conservation of Southern Bluefin Tuna (CCSBT), the final conclusion is that they may listen to science, but their strategy, allies, and the ways in which it occurs differ case-by-case.Um dos maiores desafios na governança ambiental global contemporânea é o futuro dos ecossistemas e da biodiversidade marinha. Ao longo dos anos, o aumento do esforço de pesca nas áreas anteriormente remotas levou muitas populações de peixes à escassez. As Organizações Regionais para o Ordenamento Pesqueiro (OROPs) surgiram para resolver a crise internacional de pesca, através um fórum onde os Estados-Membros podem acordar e discutir regras vinculativas para a conservação e gestão dos recursos pesqueiros no âmbito da sua área geográfica de responsabilidade. Embora alguns acordos existam há mais de 60 anos, muitos pesquisadores concordam que os mesmos não têm sido totalmente eficazes para promover a manutenção e conservação dos recursos pesqueiros. Muitas razões podem explicar a falta de eficiência no manejo, uma delas é que, o aconselhamento cientifico não é muitas vezes considerado nas decisões políticas. Nesta pesquisa, a influência do conhecimento e da ciência na tomada de decisões políticas serão avaliadas. Para isso, a teoria das comunidades epistêmicas, que faz parte da veia construtivista em Relações Internacionais, foi usada para responder à principal questão colocada aqui: quando é que o poder ouviu a ciência? E isso trouxe mais eficiência em termos do conhecimento proveniente das comunidades epistêmicas induzir os Estados a mudarem seu comportamento e a influência levar a políticas que aumentem a biomassa dos estoques pesqueiros? Com o uso de process tracing, por meio de entrevistas com atores e uma compilação sistemática dos relatórios das reuniões anuais, as OROPS: CCAMLR, ICCAT e CCSBT foram estudadas, e a conclusão final é que, os tomadores de decisão podem ouvir a ciência, porém, a estratégia, os aliados e a forma como a influência se desenvolve varia caso a caso.
34
Gall, Sarah Caroline. "Evaluating the impacts of integrating fisheries and conservation management". Thesis, University of Plymouth, 2016. http://hdl.handle.net/10026.1/8170.
Testo completoAbstract (sommario):
Historically, the governance streams of fisheries and conservation management have run separately to one another, with little attempt at integration despite their similar goals. Efforts to integrate the two have increased as a result of their similarities and the potential benefits that may arise, but a requirement for additional research was identified to determine the effectiveness of this approach. This thesis therefore took an interdisciplinary approach, seeking to combine knowledge and methods from ecological, social and economic disciplines to provide a holistic evaluation of the potential for success. Marine Protected Areas (MPAs) were chosen as a management tool to evaluate for this purpose. Ecological research used underwater video methods to show that potting may be compatible with the conservation objectives of a multi-use MPA, but that this will depend on the level of impact and what is deemed ‘acceptable’ by regulators. An evaluation of social acceptance of MPAs using Q methodology stressed the importance of stakeholder engagement and transparency in decision making. Stakeholder acceptance can be facilitated by provision of clear evidence of the need for management, and of the benefits it may bring. Economic research evaluated the potential economic benefits of multi-use MPAs through quantification of change in quantity and value of landings for potting fisheries finding landings increased following MPA implementation. Finally, the thesis considered the effectiveness of ecosystem based fisheries management using a questionnaire designed to gather the opinions of stakeholders. This highlighted the potential role of co-management and the value of the ecosystem approach and emphasised the need for responsive, adaptive management which considers all stakeholders and all three disciplines. Overall the thesis highlighted the strength of taking an interdisciplinary approach, finding that whilst there is evidence for successful integration seen through designation of well managed multi-use MPAs, success may be limited by fundamental differences in the goals of the two streams. Further success may be facilitated by increased evidence for the benefits of integration for both governance streams, and provision of adequate resources to ensure management measures are reactive and adaptive.
35
Sultan, Mohammed Akthar Riad. "Marine protected areas in the management of artisanal fisheries". Doctoral thesis, Faculty of Commerce, 2019. http://hdl.handle.net/11427/30334.
Testo completoAbstract (sommario):
This thesis examines spatial patterns of effort by fishers in waters adjoining a marine protected area, and their impacts on the reserve’s ability to reduce the impacts of overfishing. The artisanal fisheries operating near Blue Bay Marine Park, Mauritius, provided case-study data for analysis. Two forms of spatial connectivity were evaluated. The first focused on spillovers of adult and juvenile fish from the MPA. Data on catch and geographical fishing location were collected from a sample of fishers over 12 months. Assessment of spillover gradients using Generalised Linear Models and economic production functions found evidence of spillovers up to 4 km from the MPA. The second connectivity study modelled fishers’ spatial behaviour, using a random utility framework and random parameters logit estimation. Fishers appeared sensitive to the expected catch, its variability, human risk and distance travelled. Expected catch and catch variability were modelled using a Just and Pope production function. The two connectivities were integrated in bioeconomic models to assess the relationship between reserve size, fishing effort and harvests. Using a Beverton and Holt recruitment function, an age-structured bioeconomic model for the dominant target species, Unicorn fish (Naso unicornis), was constructed from the catch data. In the hypothetical case of an initially over-exploited fishery, an inverted-U relationship between fisheries benefits and the Marine Park’s size was observed. No pre-reserve data was available for use as a counterfactual; the model was therefore used to estimate the pre-reserve population. This was then used to assess the performance of the Marine Park in enhancing fish population and biomass. In the light of the findings, the thesis concludes that the extent and magnitude of fishing effort should be considered when debating the placement and size of marine reserve, and proposes a step-wise approach to integrate fishers’ behaviour in the evaluation of existing and new MPAs.
36
Sterling, David J. "Modelling the physics of prawn trawling for fisheries management /". The Gap, Qld. : Sterling Trawl Gear Services, 2005. http://adt.curtin.edu.au/theses/available/adt-WCU20050921.093622.
Testo completo
37
Sterling, David John. "Modelling the physics of prawn trawling for fisheries management". Thesis, Curtin University, 2005. http://hdl.handle.net/20.500.11937/2573.
Testo completoAbstract (sommario):
Management of prawn trawling fisheries is a difficult task due to the competing interests of strongly motivated stakeholders and interest groups. This occurs because prawn trawling operations are technically complex, require large capital investments and exhibit high running costs while owners have limited property rights over the resources that they harvest. Prawn stocks are public resources and are managed with a view to provide maximum benefit to the broad community. Additionally their exploitation also involves the incidental capture of significant numbers of other animals of no commercial value (bycatch) and causes impacts on seabed morphologies, which are involved in many diverse ecosystem processes. At the policy level an intention to manage trawl fisheries in a comprehensive way is backed by a mandated approach that is designed to capture all of the above issues and interests. That approach is termed Ecological Sustainable Development (ESD). The work in this thesis is designed to produce a prediction tool for prawn trawling performance that is based on modelling the physical nature of prawn trawling activities. It is proposed that the resulting tool is essential for working to manage the multi-dimensional aspects of prawn trawling fisheries. Three discrete objectives for the thesis are; to expand and improve an existing Prawn Trawling Performance Model (PTPM) so that it is more accurate and relevant to a broader range of questions, to evaluate the capacity of the PTPM to predict the performance characteristics of real prawn trawling operations in terms of both engineering and catching performance and to investigate the problem space surrounding prawn trawl fisheries to identify and develop applications for the model. A rudimentary PTPM (Sterling 2000b) is expanded through the analysis of further empirical data collected for model and full-scale trawl gear.ght area of improvement to the PTPM were considered and in all cases significant changes were made. The accuracy of the new form of the model is here tested by comparing performance predictions with measurements of trawling performance for a variety of industrial trawl systems operated in the Queensland East Coast Trawl Fishery and also through comparing predicted trawling performance with prawn catches returned for trawlers operating in the Northern Prawn Fishery over the years 1970 to 2000. In the first case, errors in predicting swept area rate, considered an important performance parameter, were less than 5%. Fine scale issues were explored using the available sea mal data and a number of areas of concern within the model are highlighted. These relate to accurately quantifying the forces involved in the interaction of the trawl gear with the seabed and accurately accounting for the interaction between components within trawl systems. In the second case, the results suggest that between 50% and 60% of the variation in the seasonal catching performance of trawlers in the NPF is explained by predictions of swept area rate derived by the PTPM from the available data for that fishery. A comprehensive survey of applications for the PTPM is conducted in context with approaching the management of prawn trawling fisheries using the principles of ESD as defined by the National Strategy for ESD (1992). The Northern Prawn Fishery is used as a case study to explore in finer detail applications for the PTPM. Issues arising from the implementation of some of the applications are discussed.
38
Sterling, David John. "Modelling the physics of prawn trawling for fisheries management". Curtin University of Technology, School of Physical Sciences, 2005. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=16093.
Testo completoAbstract (sommario):
Management of prawn trawling fisheries is a difficult task due to the competing interests of strongly motivated stakeholders and interest groups. This occurs because prawn trawling operations are technically complex, require large capital investments and exhibit high running costs while owners have limited property rights over the resources that they harvest. Prawn stocks are public resources and are managed with a view to provide maximum benefit to the broad community. Additionally their exploitation also involves the incidental capture of significant numbers of other animals of no commercial value (bycatch) and causes impacts on seabed morphologies, which are involved in many diverse ecosystem processes. At the policy level an intention to manage trawl fisheries in a comprehensive way is backed by a mandated approach that is designed to capture all of the above issues and interests. That approach is termed Ecological Sustainable Development (ESD). The work in this thesis is designed to produce a prediction tool for prawn trawling performance that is based on modelling the physical nature of prawn trawling activities. It is proposed that the resulting tool is essential for working to manage the multi-dimensional aspects of prawn trawling fisheries. Three discrete objectives for the thesis are; to expand and improve an existing Prawn Trawling Performance Model (PTPM) so that it is more accurate and relevant to a broader range of questions, to evaluate the capacity of the PTPM to predict the performance characteristics of real prawn trawling operations in terms of both engineering and catching performance and to investigate the problem space surrounding prawn trawl fisheries to identify and develop applications for the model. A rudimentary PTPM (Sterling 2000b) is expanded through the analysis of further empirical data collected for model and full-scale trawl gear.ght area of improvement to the PTPM were considered and in all cases significant changes were made. The accuracy of the new form of the model is here tested by comparing performance predictions with measurements of trawling performance for a variety of industrial trawl systems operated in the Queensland East Coast Trawl Fishery and also through comparing predicted trawling performance with prawn catches returned for trawlers operating in the Northern Prawn Fishery over the years 1970 to 2000. In the first case, errors in predicting swept area rate, considered an important performance parameter, were less than 5%. Fine scale issues were explored using the available sea mal data and a number of areas of concern within the model are highlighted. These relate to accurately quantifying the forces involved in the interaction of the trawl gear with the seabed and accurately accounting for the interaction between components within trawl systems. In the second case, the results suggest that between 50% and 60% of the variation in the seasonal catching performance of trawlers in the NPF is explained by predictions of swept area rate derived by the PTPM from the available data for that fishery. A comprehensive survey of applications for the PTPM is conducted in context with approaching the management of prawn trawling fisheries using the principles of ESD as defined by the National Strategy for ESD (1992). The Northern Prawn Fishery is used as a case study to explore in finer detail applications for the PTPM. Issues arising from the implementation of some of the applications are discussed.
39
Castro, Carlos J. "Contesting sustainable development : capitalist underdevelopment and resistance in the fishing communities of Pearl Lagoon, Nicaragua /". view abstract or download file of text, 2004. http://wwwlib.umi.com/cr/uoregon/fullcit?p3120614.
Testo completoAbstract (sommario):
Thesis (Ph. D.)--University of Oregon, 2004.Typescript. Includes vita and abstract. Includes bibliographical references (leaves 247-261). Also available for download via the World Wide Web; free to University of Oregon users.
40
Smith, Kristen Lynn. "Fisheries co-management and the Tahltan First Nation, from the aboriginal fisheries strategy to a treaty regime". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ33808.pdf.
Testo completo
41
Scott-Denton, Elizabeth. "U.S. southeastern shrimp and reef fish resources and their management". [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-1676.
Testo completo
42
Driscoll, John David. "Life cycle environmental impacts of Gulf of Maine lobster and herring fisheries management decisions". Restricted access (UM), 2008. http://libraries.maine.edu/gateway/oroauth.asp?file=orono/etheses/37803141.pdf.
Testo completoAbstract (sommario):
These (Ph.D.)--Dalhousie University, 2008.Title from PDF title page. Abstract, table of contents in French and English. Available through UMI ProQuest Digital Dissertations. Includes bibliographical references (leaves 88-97). Also issued in print.
43
Ish, Teresa Lin. "Conceptual tools for managing two Monterey Bay fisheries". scroll down to "CSTAR Publications, Theses and Technical Reports" section to link to desired title, 2003. http://www.cse.ucsc.edu/%7Emsmangel/CSTAR.html.
Testo completo
44
Torsteinsson, Torsteinn. "Fisheries Management in a General Equilibrium Framework / Fiskeri management i general ligevægts regi". Aarhus : Institut for Økonomi, Aarhus Universitet, 2008. http://mit.econ.au.dk/Library/Specialer/2008/20011560.pdf.
Testo completo
45
Grace-Mccaskey, Cynthia. "Fishermen, Politics, and Participation: An Ethnographic Examination of Commercial Fisheries Management in St. Croix, U.S. Virgin Islands". Scholar Commons, 2012. http://scholarcommons.usf.edu/etd/4054.
Testo completoAbstract (sommario):
Currently, there is widespread debate regarding the overall status of the world's fisheries, with some researchers projecting their total collapse in only a few decades, and others concluding the situation is not quite as bleak. Additional debates include what strategies should be used to manage fisheries at various scales, and further research is needed to determine which strategies are most appropriate for use in particular situations and locales, as context is critical.
Recently, prominent common pool resources scholars have expressed the need for ethnographic approaches to studying resource management institutions in order to move beyond the current focus of simply identifying the factors and conditions that lead to the self-organization of resource users and long-term sustainability of management institutions. These authors describe the need for examining the larger context in which management institutions exist and taking various historical, political, and sociocultural factors into account when examining common pool resources. This dissertation is a response to that request.
This research is the result of over 20 months of ethnographic research in St. Croix, United States Virgin Islands (USVI). Drawing on research in political ecology and building on anthropological critiques of common pool resource institutions, I describe the historical, social, and political factors that influence how fisheries management occurs at the federal and territorial levels, and how commercial fishers, managers, and other stakeholders experience and participate in multi-scale management processes. Ethnographic data suggest that there are a variety of historical, social, and political factors that influence how commercial fishers, managers, and other stakeholders perceive the federal fisheries management process, the extent of their participation in that process, as well as interactions within and between stakeholder groups. Additionally, the mismatch that exists between the centralized management structure of the US federal system and the small-scale, multi-method nature of St. Croix's fishery creates a complex management environment in which few stakeholders participate.
46
Ririnui, Teneti, e n/a. "The recognition of Maori customary fisheries in New Zealand�s fisheries management regime : a case study of taiapure". University of Otago. Department of Geography, 1997. http://adt.otago.ac.nz./public/adt-NZDU20070530.143237.
Testo completoAbstract (sommario):
The Treaty of Waitangi specifically recognises the rights of Maori to control and manage their fisheries resources. However, since the imposition of fisheries legislation in New Zealand, this right has been consistently eroded. It is only recently that Maori customary fisheries rights have been given a degree of recognition in New Zealand�s fisheries management regime.
The taiapure provisions of the Fisheries Act 1996 are one of the few policy initiatives available for Maori to manage their fisheries resources in accordance with their customary tikanga. This study examines the effectiveness of the taiapure legislation in providing for Maori customary fisheries management. The Maketu taiapure in the Bay of Plenty is studied to analyse the implementation of the initiative at the local level.
The study has found that there are limitations inherent in the legislation and that these are further complicated by inadequacies in its implementation. Recommendations regarding the size, management and establishment process, are made at the conclusion of the study to highlight the amendments needed for the taiapure provisions to properly recognise and provide for the role of Maori, as Treaty partners, in the management of their local fisheries.
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Liao, Yih-Yia. "Fisheries ecology of common wolffish, Anarhichas lupus, in the North Sea". Thesis, Durham University, 1999. http://etheses.dur.ac.uk/4403/.
Testo completoAbstract (sommario):
The common wolffish (Anarhichas lupus), a benthivorous species, is widely dispersed, although not abundant in the North Sea north of 54ºN latitude. Despite being widely distributed in sub Arctic and cold North Atlantic waters, little is known of the ecology of this species in the North Sea. This thesis aimed to provide ecological information for this species at the southern limit of its range in the Northeast Atlantic. North Sea common wolffish are regarded as sedentary in habit and mainly inhabited depths ranging from 60 m to 150 m. The bottom temperatures where this species were found in the North Sea ranged between 3ºC and 12ºC. The common wolffish is a by-catch species for the North Sea bottom trawl fishery. The long-term catch data and CPUE (catch per unit effort) indicated that the stock abundance of North Sea common wolfish has been decreasing over the last decades. However, it is suggested from VPA (virtual population analysis) and Yield-per-recruit analysis, that the North Sea common wolfish stock is still in a safe condition but has been overexploited. The means of total mortality (Z), natural mortality (M) and fishing mortality (F) of this species for 1996-1998 were 0.47, 0.17 and 0.30, respectively. Both resting metabolic rate (RMR) and maximum metabolic rate (MMR) were low for this species. RMR and MMR were measured for six adult common wolffish (mean weight, 1.39kg) at 5ºC and 10ºC. At 5ºC the mean RMR± SE was 12.18 ± 1.6 mgO(_2),kg(^-1)h(^-1), and mean MMR ± SE was 70.65 ± 7.63 mgO(_2)kg(^-1)h(^-1). At 10ºC the mean RMR±SE was 25.43 ±1.31 mgO(_2) kg (^-1)h(^-1), and mean MMR ± SE was 113.84 ± 16.26 mgO(_2) kg(^-1)h(^-1). Absolute metabolic scope was 53% greater at 10ºC than at 5ºC.The main food for common wolffish in the North Sea were Decapoda comprising 39 % of the overall diet by occurrence, with hermit crabs (Paguridae) being the dominant species. Other important dietary components were Bivalvia (20 %) and Gastropoda (12 %). Sea urchins (Echinidae), which are important prey of common wolffish in eastern Newfoundland, Gulf of Maine and Iceland, but typically of low energy value, occupied only 7 % of the diet. During the autumn/winter season, wolffish consumed less food compared with the remainder of the year. From this study, von Bertalanffy growth parameters for common wolffish in the North Sea were calculated to be: for male, L(_oo)= 111.2 cm, t(_o) = -0.43 and = 0.12; and for female, L(_oo)= 115.1 cm, t(_o)= -0.39 and K = 0.11, making North Sea common wolffish the fastest growing stock of this species reported. The fast growth of North Sea common wolffish may be a result of the higher energy content of the diet or greater metabolic scope available for food processing. This increased metabolic scope being associated with life in the warmer North Sea, in comparison to those stocks found elsewhere in the range of this typically sub-Arctic species. The maximum age found for this species in the North Sea was 18 years old. Median length at sexual maturity of male and female common wolffish is at 51.9 cm and 50.4 cm respectively, with the age of sexual maturity being achieved at 4-5 years in the North Sea. The spawning season of North Sea common wolffish is from October through to February. The fecundity varied with the body weight of females, from several thousand to 12,000 eggs. Ripe egg sizes ranged from 5 mm to 6.5 mm. Spermatozoa were found in mature male individuals throughout the whole year with the highest peak in October.
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McCafferty, James Ross. "An assessment of inland fisheries in South Africa using fisheries-dependent and fisheries-independent data sources". Thesis, Rhodes University, 2012. http://hdl.handle.net/10962/d1005072.
Testo completoAbstract (sommario):
The role of inland fisheries as contributors to local and national economies in developing African countries is well documented. In South Africa, there is increasing interest in inland fisheries as vehicles for achieving national policy objectives including food security, livelihoods provision, poverty alleviation and economic development but there is surprisingly little literature on the history, current status, and potential of inland fishery resources. This lack of knowledge constrains the development of management strategies for ensuring the biological sustainability of these resources and the economic and social sustainability of the people that are dependent on them. In order to contribute to the knowledge base of inland fisheries in South Africa this thesis: (1) presents an exhaustive review of the available literature on inland fisheries in South Africa; (2) describes the organisation of recreational anglers (the primary users of the resource); (3) compiles recreational angling catch records and scientific gill net survey data, and assesses the applicability of these data for providing estimates of fish abundance (catch-per-unit effort [CPUE]); and finally, (4) determines the potential for models of fish abundance using morphometric, edaphic, and climatic factors. The literature review highlighted the data-poor nature of South African inland fisheries. In particular information on harvest rates was lacking. A lack of knowledge regarding different inland fishery sectors, governance systems, and potential user conflicts was also found. Recreational anglers were identified as the dominant user group and catch data from this sector were identified as potential sources of fish abundance and harvest information. Formal freshwater recreational angling in South Africa is a highly organised, multi-faceted activity which is based primarily on angling for non-native species, particularly common carp Cyprinus carpio and largemouth bass Micropterus salmoides. Bank anglers constituted the largest number of formal participants (5 309 anglers affiliated to formal angling organisations) followed by bass anglers (1 184 anglers affiliated to formal angling organisations). The highly structured nature of organised recreational angling and dominant utilisation of inland fisheries resources by this sector illustrated not only the vested interest of anglers in the management and development of inland fisheries but also the role that anglers may play in future decision-making and monitoring through the dissemination of catch data from organised angling events. Generalised linear models (GLMs) and generalised additive models (GAMs) were used to standardise CPUE estimates from bass- and bank angling catch records, which provided the most suitable data, and to determine environmental variables which most influenced capture probabilities and CPUE. Capture probabilities and CPUE for bass were influenced primarily by altitude and conductivity and multiple regression analysis revealed that predictive models incorporating altitude, conductivity, surface area and capacity explained significant (p<0.05) amounts of variability in CPUE (53%), probability of capture (49%) and probability of limit bag (74%). Bank angling CPUE was influenced by conductivity, surface area and rainfall although an insignificant (p>0.05) amount of variability (63%) was explained by a predictive model incorporating these variables as investigations were constrained by small sample sizes and aggregated catch information. Scientific survey data provided multi-species information and highlighted the high proportion of non-native fish species in Eastern Cape impoundments. Gillnet catches were influenced primarily by species composition and were less subject to fluctuations induced by environmental factors. Overall standardised gillnet CPUE was influenced by surface area, conductivity and age of impoundment. Although the model fit was not significant at the p<0.05 level, 23% of the variability in the data was explained by a predictive model incorporating these variables. The presence of species which could be effectively targeted by gillnets was hypothesised to represent the most important factor influencing catch rates. Investigation of factors influencing CPUE in impoundments dominated by Clarias gariepinus and native cyprinids indicated that warmer, younger impoundments and smaller, colder impoundments produced higher catches of C. gariepinus and native cyprinids respectively. A predictive model for C. gariepinus abundance explained a significant amount of variability (77%) in CPUE although the small sample size of impoundments suggests that predictions from this model may not be robust. CPUE of native cyprinids was influenced primarily by the presence of Labeo umbratus and constrained by small sample size of impoundments and the model did not adequately explain the variability in the data (r² = 0.31, p>0.05). These results indicate that angling catch- and scientific survey data can be useful in providing predictions of fish abundance that are biologically realistic. However, more data over a greater spatial scale would allow for more robust predictions of catch rates. This could be achieved through increased monitoring of existing resource users, the creation of a centralised database for catch records from angling competitions, and increased scientific surveys of South African impoundments conducted by a dedicated governmental function.
49
Wenig, Michael Moers. "The Fisheries Act as a legal framework for watershed management". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape9/PQDD_0020/MQ47929.pdf.
Testo completo
50
Brzezinski, Danielle. "Ecological and Policy Implications of Voluntary Participation in Fisheries Management". Fogler Library, University of Maine, 2009. http://www.library.umaine.edu/theses/pdf/BrzezinskiD2009.pdf.
Testo completo