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A Oude G J M Lansink - One of the best experts on this subject based on the ideXlab platform.
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adoption of recirculating Aquaculture Systems in pangasius farms a choice experiment
Aquaculture, 2016Co-Authors: J A J Verreth, R H Bosma, Pham Thi Ngoc, M P M Meuwissen, A Oude G J M LansinkAbstract:Abstract In response to increasing concerns about sustainable production, a growing number of European customers expect seafood products to be certified, e.g. by ASC certification. A possible answer to achieve environmental sustainability of Vietnamese pangasius farming is to apply recirculating Aquaculture Systems (RASs) at the farm. However, RAS requires relatively high initial investments and therefore its adoption depends largely on the economic feasibility in the Vietnamese farming context. The latter includes not only economic factors but also socio-demographic characteristics of the farmers.This study uses a choice experiment to measure farmers' preferences for RAS in pangasius production in Vietnam. Findings show that the probability of adopting RAS is positively associated with expected higher yields and ASC certification with a price premium, whereas it is negatively associated with the initial investment. Location of a farm is also important, i.e. farmers in saltwater intrusion areas are more likely to implement RAS compared to those in freshwater areas. Other variables significantly associated with the probability of adopting RAS are age, education, gender, and household income. The overall probability of adopting RAS was low; the main constraints for adoption of RAS were farmers' uncertainty about the performance of RAS, lack of access to finance and lack of certainty about receiving the ASC price premium. To stimulate the adoption of RAS, we recommend that policy makers target farmers with farms located in saltwater intrusion areas. We further recommend policies that link access to credit with investments in sustainability, and the establishment of pioneer RAS farms as a way to disseminate information about RAS and reduce farmers' uncertainty. Lastly, we recommend that retailers guarantee price premiums for ASC-certified pangasius. Statement of relevance Adoption of recirculating Aquaculture Systems is considered to be an important step to achieve compliance with sustainability certifications and disease control in pangasius farming. As a result, retailers and buyers in the EU can find pangasius products from environmentally sustainable and socially equitable production Systems.
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economic feasibility of recirculating Aquaculture Systems in pangasius farming
Aquaculture Economics & Management, 2016Co-Authors: T A N Pham, J A J Verreth, M P M Gielenmeuwissen, R H Bosma, A Oude G J M LansinkAbstract:This study aims to analyze the economic feasibility of recirculating Aquaculture Systems (RAS) in pangasius farming in Vietnam. The study uses a capital budgeting approach and accounts for uncertainty in key parameters. Stochastic simulation is used to simulate the economic performance of medium and large farms operating with a traditional system or RAS. Data are obtained through structured surveys and a workshop in the Mekong River Delta. Results show that for large farms, net present value increases from an average of 589,000 USD/ha to 916,000 USD/ha after implementing RAS. Overall, the probability that RAS is a profitable investment is found to be 99% for both farm sizes. With RAS, the crucial parameters determining profitability are price, yield, costs of fingerling, feed, and initial investment. Findings on the robustness of the economic performance of RAS are useful to support public and private decision making towards increasing the sustainability of pangasius production.
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adoption of recirculating Aquaculture Systems in pangasius farms a choice experiment
Research Papers in Economics, 2015Co-Authors: J A J Verreth, R H Bosma, Pham Thi Ngoc, M P M Meuwissen, A Oude G J M LansinkAbstract:A growing number of European customers’ demands certified pangasius such as ASC in order to ensure sustainable production. Implementing Recirculating Aquaculture Systems (RAS) contributes to an improved water quality, a key issue in achieving ASC certification. This study uses a choice experiment to measure farmers’ preferences for RAS in pangasius production in Vietnam. The farmers’ choice for RAS is positively affected by enhanced yield levels and achievement of ASC certification with price premium. Also the area of farming is found to be important, i.e. farmers in saltwater intrusion areas are more likely to implement RAS. Main constraints are availability of finance and lack of trust in receiving the ASC price premium. To stimulate the adoption of RAS, policies can provide interest subsidies on loans to finance RAS investment, while retailers could ensure a price premium for ASC certified pangasius.
Pham Thi Ngoc - One of the best experts on this subject based on the ideXlab platform.
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adoption of recirculating Aquaculture Systems in pangasius farms a choice experiment
Aquaculture, 2016Co-Authors: J A J Verreth, R H Bosma, Pham Thi Ngoc, M P M Meuwissen, A Oude G J M LansinkAbstract:Abstract In response to increasing concerns about sustainable production, a growing number of European customers expect seafood products to be certified, e.g. by ASC certification. A possible answer to achieve environmental sustainability of Vietnamese pangasius farming is to apply recirculating Aquaculture Systems (RASs) at the farm. However, RAS requires relatively high initial investments and therefore its adoption depends largely on the economic feasibility in the Vietnamese farming context. The latter includes not only economic factors but also socio-demographic characteristics of the farmers.This study uses a choice experiment to measure farmers' preferences for RAS in pangasius production in Vietnam. Findings show that the probability of adopting RAS is positively associated with expected higher yields and ASC certification with a price premium, whereas it is negatively associated with the initial investment. Location of a farm is also important, i.e. farmers in saltwater intrusion areas are more likely to implement RAS compared to those in freshwater areas. Other variables significantly associated with the probability of adopting RAS are age, education, gender, and household income. The overall probability of adopting RAS was low; the main constraints for adoption of RAS were farmers' uncertainty about the performance of RAS, lack of access to finance and lack of certainty about receiving the ASC price premium. To stimulate the adoption of RAS, we recommend that policy makers target farmers with farms located in saltwater intrusion areas. We further recommend policies that link access to credit with investments in sustainability, and the establishment of pioneer RAS farms as a way to disseminate information about RAS and reduce farmers' uncertainty. Lastly, we recommend that retailers guarantee price premiums for ASC-certified pangasius. Statement of relevance Adoption of recirculating Aquaculture Systems is considered to be an important step to achieve compliance with sustainability certifications and disease control in pangasius farming. As a result, retailers and buyers in the EU can find pangasius products from environmentally sustainable and socially equitable production Systems.
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adoption of recirculating Aquaculture Systems in pangasius farms a choice experiment
Research Papers in Economics, 2015Co-Authors: J A J Verreth, R H Bosma, Pham Thi Ngoc, M P M Meuwissen, A Oude G J M LansinkAbstract:A growing number of European customers’ demands certified pangasius such as ASC in order to ensure sustainable production. Implementing Recirculating Aquaculture Systems (RAS) contributes to an improved water quality, a key issue in achieving ASC certification. This study uses a choice experiment to measure farmers’ preferences for RAS in pangasius production in Vietnam. The farmers’ choice for RAS is positively affected by enhanced yield levels and achievement of ASC certification with price premium. Also the area of farming is found to be important, i.e. farmers in saltwater intrusion areas are more likely to implement RAS. Main constraints are availability of finance and lack of trust in receiving the ASC price premium. To stimulate the adoption of RAS, policies can provide interest subsidies on loans to finance RAS investment, while retailers could ensure a price premium for ASC certified pangasius.
Zhongming Zheng - One of the best experts on this subject based on the ideXlab platform.
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Succession of bacterioplankton community in intensive shrimp (Litopenaeus vannamei) Aquaculture Systems
Aquaculture, 2018Co-Authors: Wen Yang, Jinyong Zhu, Cheng Zheng, Haijie Qiu, Zhongming ZhengAbstract:Abstract Bacterioplankton play an integral role in Aquaculture Systems, but our understanding of the succession of bacterioplankton community along intensive shrimp cultivation is fragmentary. Here we used high-throughput sequencing technique to study the dynamics of bacterioplankton community during the process of intensive shrimp (Litopenaeus vannamei) cultivation, and link community changes to physicochemical and biological factors. Community composition varied dramatically over time, supporting the idea of significant unidirectional temporal change in bacterioplankton assemblages, and could be clustered into 4 seral stages by CLUSTER analysis. Different dominant taxa were identified in different seral stages. Furthermore, we used a RMT-based network method to reveal the interspecies interactions among different bacterioplankton and found that these interactions were also dynamic along bacterioplankton succession. Canonical correspondence analysis and Pearson correlations showed that ammonium, nitrite, dissolved oxygen, cryptophytes and green algae constrained community composition by affecting the relative abundance of susceptible species. Besides, Candidatus Aquiluna rubra was identified as the keystone and generalist of the entire network, suggestive of an important role in driving bacterioplankton succession. These findings expand our understanding of the underlying mechanisms of bacterioplankton succession in ponds with intensive rearing shrimp, and suggest that stabilizing environmental variables (e.g. increasing DO, minimizing nutrient pollution and regulating phytoplankton community) could be a useful management tool for promoting and maintaining healthy Aquaculture environments.
J A J Verreth - One of the best experts on this subject based on the ideXlab platform.
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adoption of recirculating Aquaculture Systems in pangasius farms a choice experiment
Aquaculture, 2016Co-Authors: J A J Verreth, R H Bosma, Pham Thi Ngoc, M P M Meuwissen, A Oude G J M LansinkAbstract:Abstract In response to increasing concerns about sustainable production, a growing number of European customers expect seafood products to be certified, e.g. by ASC certification. A possible answer to achieve environmental sustainability of Vietnamese pangasius farming is to apply recirculating Aquaculture Systems (RASs) at the farm. However, RAS requires relatively high initial investments and therefore its adoption depends largely on the economic feasibility in the Vietnamese farming context. The latter includes not only economic factors but also socio-demographic characteristics of the farmers.This study uses a choice experiment to measure farmers' preferences for RAS in pangasius production in Vietnam. Findings show that the probability of adopting RAS is positively associated with expected higher yields and ASC certification with a price premium, whereas it is negatively associated with the initial investment. Location of a farm is also important, i.e. farmers in saltwater intrusion areas are more likely to implement RAS compared to those in freshwater areas. Other variables significantly associated with the probability of adopting RAS are age, education, gender, and household income. The overall probability of adopting RAS was low; the main constraints for adoption of RAS were farmers' uncertainty about the performance of RAS, lack of access to finance and lack of certainty about receiving the ASC price premium. To stimulate the adoption of RAS, we recommend that policy makers target farmers with farms located in saltwater intrusion areas. We further recommend policies that link access to credit with investments in sustainability, and the establishment of pioneer RAS farms as a way to disseminate information about RAS and reduce farmers' uncertainty. Lastly, we recommend that retailers guarantee price premiums for ASC-certified pangasius. Statement of relevance Adoption of recirculating Aquaculture Systems is considered to be an important step to achieve compliance with sustainability certifications and disease control in pangasius farming. As a result, retailers and buyers in the EU can find pangasius products from environmentally sustainable and socially equitable production Systems.
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economic feasibility of recirculating Aquaculture Systems in pangasius farming
Aquaculture Economics & Management, 2016Co-Authors: T A N Pham, J A J Verreth, M P M Gielenmeuwissen, R H Bosma, A Oude G J M LansinkAbstract:This study aims to analyze the economic feasibility of recirculating Aquaculture Systems (RAS) in pangasius farming in Vietnam. The study uses a capital budgeting approach and accounts for uncertainty in key parameters. Stochastic simulation is used to simulate the economic performance of medium and large farms operating with a traditional system or RAS. Data are obtained through structured surveys and a workshop in the Mekong River Delta. Results show that for large farms, net present value increases from an average of 589,000 USD/ha to 916,000 USD/ha after implementing RAS. Overall, the probability that RAS is a profitable investment is found to be 99% for both farm sizes. With RAS, the crucial parameters determining profitability are price, yield, costs of fingerling, feed, and initial investment. Findings on the robustness of the economic performance of RAS are useful to support public and private decision making towards increasing the sustainability of pangasius production.
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adoption of recirculating Aquaculture Systems in pangasius farms a choice experiment
Research Papers in Economics, 2015Co-Authors: J A J Verreth, R H Bosma, Pham Thi Ngoc, M P M Meuwissen, A Oude G J M LansinkAbstract:A growing number of European customers’ demands certified pangasius such as ASC in order to ensure sustainable production. Implementing Recirculating Aquaculture Systems (RAS) contributes to an improved water quality, a key issue in achieving ASC certification. This study uses a choice experiment to measure farmers’ preferences for RAS in pangasius production in Vietnam. The farmers’ choice for RAS is positively affected by enhanced yield levels and achievement of ASC certification with price premium. Also the area of farming is found to be important, i.e. farmers in saltwater intrusion areas are more likely to implement RAS. Main constraints are availability of finance and lack of trust in receiving the ASC price premium. To stimulate the adoption of RAS, policies can provide interest subsidies on loans to finance RAS investment, while retailers could ensure a price premium for ASC certified pangasius.
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steroids accumulate in the rearing water of commercial recirculating Aquaculture Systems
Aquacultural Engineering, 2014Co-Authors: Vasco C Mota, Catarina I M Martins, E H Eding, Adelino V M Canario, J A J VerrethAbstract:Abstract Little information is available on steroid concentrations in the rearing water of Aquaculture Systems and whether they accumulate in recirculating Aquaculture Systems (RAS). Therefore this study aimed at determining (1) the concentrations and variation of cortisol and sex steroids in RAS, (2) the contribution of fish rearing conditions to steroid concentrations in seven commercial RAS. Each RAS was sampled twice at three different points: (1) make-up water; (2) influent and (3) effluent of the rearing unit. The results showed significant higher steroid concentrations in the influent and effluent when compared with the make-up water. On average cortisol concentration was 15.7% higher in the effluent when compared with the influent. Mean steroid concentrations in the rearing unit effluent varied between: 3.8–217.0 ng/L for cortisol, 3–12.5 ng/L for testosterone, 0.9–7.1 ng/L for 11-ketoteststerone and 1.8–12.8 ng/L for 17,20β-dihydroxypregn-4-en-3-one. Stocking density, Total Ammonia-Nitrogen concentration and orthophosphate-P concentration (a measure of make-up water usage) showed a positive correlation with sex steroids in the water. The steroid concentrations from the present study were orders of magnitude lower than initial estimations indicating a water treatment efficiency of >99%. The results suggest that an intensification of fish production through decrease of make-up water use and increase of stocking density will lead to a build-up of steroids in the water. Although intensification is critical for the economical success of RAS, this ultimately could affect fish performance as steroids accumulates in the water of RAS at levels that can potentially be detected by some fish species.
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analysis of nutrient flows in integrated intensive Aquaculture Systems
Aquacultural Engineering, 2005Co-Authors: Oliver Schneider, E H Eding, V Sereti, J A J VerrethAbstract:Abstract This paper analyses nutrient conversions, which are taking place in integrated intensive Aquaculture Systems. In these Systems fish is cultured next to other organisms, which are converting otherwise discharged nutrients into valuable products. These conversions are analyzed based on nitrogen and phosphorous balances using a mass balance approach. The analytical concept of this review comprises a hypothetical system design with five modules: (1) the conversion of feed nutrients into fish biomass, the “Fish-Biomass-Converter”; (2) the separation of solid and dissolved fish waste/nutrients; the “Fish-Waste-Processor”; (3) the conversion of dissolved fish waste/nutrients, the “Phototrophic-herbivore-Converter”; (4 and 5) the conversion of solid fish waste, the “Bacterial-Waste-Converter”, or the “Detrivorous-Converter”. In the reviewed examples, fish culture alone retains 20–50% feed nitrogen (N) and 15–65% feed phosphorous (P). The combination of fish culture with phototrophic conversion increases nutrient retention of feed N by 15–50% and feed P by up to 53%. If in addition herbivore consumption is included, nutrient retention decreases by 60–85% feed N and 50–90% feed P. This is according to the general observation of nutrient losses from one trophic level to the next. The conversion of nutrients into bacteria and detrivorous worm biomass contributes only in smaller margins (e.g. 7% feed N and 6% feed P and 0.06% feed N 0.03 × 10−3% feed P, respectively). All integrated modules have their specific limitations, which are related to uptake kinetics, nutrient preference, unwanted conversion processes and abiotic factors.
Eiichiro Fukusaki - One of the best experts on this subject based on the ideXlab platform.
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metabolite profiling of whiteleg shrimp litopenaeus vannamei from super intensive culture in closed Aquaculture Systems a recirculating Aquaculture system and a hybrid zero water discharge recirculating Aquaculture system
Metabolomics, 2020Co-Authors: Gede Suantika, Magdalena Lenny Situmorang, Felicia Irene Saputra, Safira Latifa Erlangga Putri, Pingkan Aditiawati, Sastia Prama Putri, Eiichiro FukusakiAbstract:INTRODUCTION: The production of the whiteleg shrimp Litopenaeus vannamei now accounts for approximately 75% of the total shrimp production in Indonesia. The techniques used to produce whiteleg shrimp in Indonesia are still dominated by conventional rearing strategies using open-pond Systems, which often contribute to unpredictable culture performance and weak sustainability. Alternative production strategies of closed Aquaculture Systems, including the recirculating Aquaculture system (RAS) and hybrid zero water discharge-recirculating Aquaculture system (hybrid system), have been developed and implemented for higher productivity, stability and sustainability of whiteleg shrimp grow-out production in Indonesia. Despite the positive aspects of the application of closed Aquaculture Systems in shrimp Aquaculture, the differences in the characteristics of shrimp grown in closed RAS and hybrid Systems compared to open-pond Systems remain unclear. OBJECTIVE: This study aims to investigate the differences in the metabolite profiles of shrimp grown in intensive closed Aquaculture Systems, including an RAS and hybrid system, compared to those of shrimp grown in a semi-intensive, open, earthen pond system by means of non-targeted GC-MS metabolite profiling. METHODS: Shrimp cultured in the closed Systems (RAS and hybrid system) and an open system (pond) were harvested and subjected to GC-MS non-targeted metabolomics analysis. A total of 112 metabolites were annotated from shrimp samples and subjected to principal component analysis (PCA). RESULTS: The metabolites annotated from GC-MS mainly included organic compounds, proteinogenic and non-proteinogenic amino acids, sugars, nucleosides and fatty acids. The results of principal component analysis showed several metabolites with high variable importance in projection (VIP) scores, including shikimic acid, β-alanine, uric acid, hypoxanthine, inosine, homocysteine, methionine, phenylalanine, tryptophan and lysine, as the main metabolites differentiating the shrimp grown in the three production Systems. CONCLUSION: Our findings showed that shrimp cultured in different Aquaculture Systems exhibited distinct metabolite profiles, and the metabolites showing high VIP scores, including shikimic acid, β-alanine, uric acid, hypoxanthine, inosine, homocysteine, methionine, phenylalanine, tryptophan and lysine, may serve as candidate markers to indicate the differences in shrimp from different production Systems.