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dc.contributor.advisorArmstrong, Claire W.
dc.contributor.authorLe Thi Thanh, Ngan
dc.date.accessioned2023-11-28T12:56:54Z
dc.date.available2023-11-28T12:56:54Z
dc.date.issued2023-12-08
dc.description.abstractThis thesis delves into three key research areas centered on shrimp farming: evaluating operational efficiency in shrimp farming, analyzing adaptive choices made by farmers, and forecasting disease occurrences in shrimp farms in the context of evolving climate and environmental influences. The research employed a blend of methodologies derived from pertinent literature, coupled with data acquired through surveys. Rigorous checks for robustness were employed, leading to statistically substantial outcomes that address various inquiries concerning the economic facets of shrimp cultivation in the face of severe weather conditions. The specific locale chosen for this study is the Vannamei shrimp farming in the provinces of Bac Lieu and Ca Mau, situated in the Mekong Delta of South Vietnam. These provinces hold diverse shrimp farming systems and contribute significantly to the nation's shrimp output. Their geographical vulnerability to the impacts of climate change also aligns well with the study's core objectives. The first objective assessed efficiency in shrimp yield for both intensive and extensive systems, linking factors like climate perception, education, adaptation, disease, and location to efficiency. This aids in identifying factors that mitigate inefficiencies in well-managed farms during adverse weather. The second objective analyzed factors influencing farmers' choices in adopting adaptive measures across intensive and extensive systems. Socioeconomic status, knowledge sharing, access to services, farm characteristics, and perceptions were key factors shaping adaptive decisions, with policy implications for climate adaptation in shrimp farming. The final objective predicted disease outbreaks in intensive shrimp farming, identifying risk and protective factors. Training, extension services, and protective measures were crucial in minimizing disease, with shrimp crop duration and operational years affecting disease likelihood.en_US
dc.description.doctoraltypeph.d.en_US
dc.description.popularabstractThis thesis covers three primary focal research areas: estimating efficiency in shrimp farming, assessing farmers' choices of adaptive measures, and predicting disease occurrence in shrimp farms under the impact of perceived climate and environmental issues. The research methods were selected from relevant literature and applied to the surveyed data, combined with robustness checks, providing statistically significant results responding to various research questions related to the economics of shrimp farming under the influence of extreme weather. Vannamei shrimp farming in Bac Lieu and Ca Mau provinces in the Mekong Delta of South Vietnam was used as the applied context. These two provinces have a variety of shrimp farming systems, producing a major share of shrimp production in Vietnam. In addition, these two provinces' locations are prone to diverse impacts of climate change, satisfying the focal issue studied. The first research objective targets farming efficiency regarding shrimp yield for both intensive and extensive farming systems. Our findings provide empirical evidence that shrimp farmers' perceptions of extreme climate events, education level, climate adaptation, farm's distance to the sea, disease factors in the crop, and shrimp crop duration affect the efficiency of the farming systems. Furthermore, we demonstrate that identifying determinants that increase or decrease crop inefficiencies in well-managed inland farms can provide important economic benefits given severe weather. The second research objective was to identify the drivers of farmers’ choices in different cultivation systems (intensive and extensive) using five adaptation measures to extreme weather and environmental issues in the Mekong region. Socioeconomic factors, knowledge sharing, service accessibility, farm characteristics, and farmer perceptions significantly influence farmers’ adaptation choices, providing policy implications for developing adaptive capacity to climate change in shrimp farming. The final research objective deals with disease occurrence detection in intensive shrimp farming – a rapidly emerging shrimp farming system in the Mekong due to high stocking densities and the adoption of various production inputs. This study is done to identify risk and protective factors associated with farmers and farming characteristics, as well as other aspects impacting disease outbreaks. Our findings highlight the importance of developing training activities and extension services and applying meaningful protective measures (regular feed conversion ratio calculations, feeding practice schedule changes) to minimize disease occurrence. In addition, an increase in shrimp crop length and the number of years of operation greatly affect the likelihood of disease risk. The results provide information for managing shrimp production and controlling disease.en_US
dc.description.sponsorshipThe NORHED project SRV-13/0010 is gratefully acknowledged for financial support.en_US
dc.identifier.isbn978-82-8266-255-0
dc.identifier.urihttps://hdl.handle.net/10037/31877
dc.language.isoengen_US
dc.publisherUiT The Arctic University of Norwayen_US
dc.publisherUiT Norges arktiske universiteten_US
dc.relation.haspart<p>Paper I: Le, N.T.T., Hestvik, E.B., Armstrong, C.W. & Eide, A. (2022). Determinants of inefficiency in shrimp aquaculture under environmental impacts: Comparing shrimp production systems in the Mekong, Vietnam. <i>Journal of the World Aquaculture Society, 53</i>(5), 963-983. Also available in Munin at <a href=https://hdl.handle.net/10037/26340> https://hdl.handle.net/10037/26340</a>. <p>Paper II: Le, N.T.T., Armstrong, C.W., Brækkan, E.H. & Eide, A. Climatic events and disease occurrence in intensive <i>Litopenaeus vannamei</i> shrimp farming in the Mekong area of Vietnam. (Manuscript under review). <p>Paper III: Le, N.T.T. & Armstrong, C.W. Choice of climate risk adaptation measures in shrimp farming – A case study from the Mekong, Vietnam. (Manuscript under review). Now published in <i>Aquaculture Economics & Management</i>, 2023, available at <a href=https://doi.org/10.1080/13657305.2023.2273483>https://doi.org/10.1080/13657305.2023.2273483</a>.en_US
dc.rights.accessRightsopenAccessen_US
dc.rights.holderCopyright 2023 The Author(s)
dc.subject.courseIDDOKTOR-002
dc.subjectaquaculture economicsen_US
dc.subjectclimate change adaptationen_US
dc.subjectshrimp aquaculutreen_US
dc.subjectsustainable developmenten_US
dc.titleA study of economic efficiency, adaptive measures to extreme climatic events, and drivers of disease in Vietnamese white leg shrimp aquacultureen_US
dc.typeDoctoral thesisen_US
dc.typeDoktorgradsavhandlingen_US


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