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In Vietnam, culturing striped catfish makes an important contribution to the Mekong Delta's economy. Water level rise during rainy season and salt intrusion during dry season affect the water exchange and quality for this culture. Sea level rise as a consequence of climate change will worsen these influences. In this study, water level rise and salt water intrusion for three sea level rise (SLR) scenarios (i.e., +30, +50, and +75 cm) were simulated. The results showed that at SLR +50, the 3-m-flood level would spread downstream and threaten farms located in AnGiang, DongThap and CanTho provinces. Rising salinity levels for SLR +75 would reduce the window appropriate for the culture in SocTrang and BenTre provinces, and in TienGiang's coastal districts. Next to increasing dikes to reduce the impacts, the most tenable and least disruptive option to the farming community would be to shift to a salinity tolerant strain of catfish.

Traditional farmers of milkfish and shrimp use 80% of Indonesia's shrimp production area, but produce only 10% of its shrimp. A coastal protection project funded a 16‐day aquaculture field school (AFS) in order to train 277 farmers in Low External Input Sustainable Aquaculture (LEISA). Its cost was 1,060 USD per farmer. In 2017 and 2018, the project monitoring database completed records of yields and practices of 125 participants and monitored finances and water quality in a 10% sample. LEISA was adopted by 85% of the 125 participants. The two annual datasets of the sample were merged and trimmed from three outliers; this was done before statistical analysis. Compared to the baseline, LEISA adopters among the 125 tripled their shrimp' yields. Within the sample, the milkfish yields of adopters and non‐adopters were about identical. Sampled adopters significantly increased their gross margin by 927 USD ha−1 year−1 due to three‐ and fivefold yield increases for milkfish and shrimp compared to that of the baseline. The rate of return was 1.3 for the 277 participants and 1.8 for the sample, indicating a payback time of <1 year. Enriching the farmers' skills with AFS can double Indonesian milkfish production and increase its shrimp production by 25–50%. [ABSTRACT FROM AUTHOR]

Gender equality has been a political issue in view of human rights and welfare since several decades. Therefore, many countries have developed Gender Action Plans (GAPs) that support equal access of both sexes to education, employment and finance. Two workshops on GAPs in aquaculture and a literature review brought about the question: what's missing in Asian sectoral GAPs. Not all reviewed Asian countries have GAPs for fishery/ aquaculture, but all encountered constraints to achieve their goals regarding equal access for women. Women's contribution in aquaculture tends to go beyond the traditional gender divide. For example, women may lead in the area of production because they can combine aquaculture with their homebound tasks and own vertically integrated companies. However, skewed perceptions on the role, status and perception of women and men, more so in strong than weak patriarchies (the former accept the subservient role, while the latter exercise the dominant role) limit women's access to training opportunities on new aquaculture technologies. Women are also left out in policy‐ and decision‐making processes; and in the value chain, women receive lower wages than men. Their role is underestimated by lack of disaggregated data, as reflected in post‐disaster interventions and industrial development programs. To be effective sectoral GAPs, based on disaggregated data, should have budgets, plans and target indicators for which leaders could be held accountable. These GAPs, however, can't address the required radical change in attitude toward women; unless deliberately planned educational media campaigns are embedded into the national GAPs. [ABSTRACT FROM AUTHOR]

In the coastal area of the Vietnamese Mekong Delta, much of the mangrove forest has been cut to make space for expansion of industry and aquaculture. Export‐oriented shrimp farming is a particularly fast‐growing business. Nonetheless, the importance of tropical mangrove forest ecosystems for coastal protection and marine biodiversity is widely recognized. The Vietnamese government, supported by non‐governmental organizations and donors, has sought to restore mangrove forest. To this end, the government has promoted mixed or integrated mangrove‐shrimp systems in which farmers maintain at least 40 per cent of their area under mangrove cover. Since 2012, mangrove reforestation, care and protection has benefited from local authority stimulus as well. Multiple studies have examined the condition of the mangrove forest in Ben Tre and other coastal provinces of the Mekong Delta. However, no research has investigated the role of social dynamics in farmers’ willingness to shift to, or maintain, integrated mangrove‐shrimp systems. Specifically, the influence of information, group dynamics and social learning on farmer decision‐making is poorly understood and, indeed, hardly investigated in Vietnam. This article reports on a study of social processes in three communes in Binh Dai District, Ben Tre Province, Vietnam. We conducted 42 semi‐structured interviews (with 34 farmers and eight local officials) and used secondary data. Our preliminary findings indicate that social dynamics in these communes were issue‐driven and played an important role in farmers’ decisions to adopt, or convert to, the integrated mangrove‐shrimp farming system. Television, radio, the internet, books, neighbours and training courses all had some influence in farmer decision‐making processes. However, our findings suggest that the accessibility, usefulness, relevance and approach of these communication methods must be improved if they are to adequately inform and support local farmers. [ABSTRACT FROM AUTHOR]

Abstract: The technical efficiency of randomly sampled pangasius farms in the Mekong Delta of Vietnam was estimated using data envelopment analysis, and factors affecting technical and scale efficiency were examined with bootstrap truncated regression. The mean technical efficiency score assuming variable returns to scale was 0.84. The technical efficiency of downstream farmers was higher due to lower energy costs and stocking once a year. Most of the up‐ and midstream farms needed to pump water and stocked at least three times in 2 yr. Regression analysis showed a positive effect on technical efficiency of the farmers' education level and having experienced climate change impact through flooding or salinity intrusion in the past. Farms affected by salinity intrusion had a lower scale efficiency as they reduce stocking frequency and rate. In general, reducing fish mortality and the cost of inputs, increasing scale of operation, and being trained, using appropriate methods, in management strategies may improve technical efficiency. [ABSTRACT FROM AUTHOR]

Vietnamese pangasius farming needs to produce efficiently to compete in world markets. This study investigates the input- and output-specific technical inefficiency of Vietnamese pangasius farmers. First, we used a Russell-type (input-output) directional distance function to estimate the input- and output-specific technical inefficiency. Second, we applied a bootstrap truncated regression to analyze the factors influencing these technical inefficiencies. Results show that the main challenges for enhancing the performance of Vietnamese pangasius production are inadequate use of capital assets (inefficiency of 42%) and improper methods to achieve higher fish yield (inefficiency of 30%). Input-specific technical inefficiency (pond area and feed) is negatively associated with the experience and education level of pangasius farmers. Location of the farm in a saltwater intrusion area is positively associated with the inefficiency of producing fish. Outcomes of this study are useful to identify successful strategies to minimize the use of inputs while simultaneously maximizing fish production. [ABSTRACT FROM AUTHOR]

The paper reviews the following three types of mangrove-shrimp systems: (i) integrated with canals between platforms planted with mangrove; (ii) associated having larger areas of water and a large mangrove area; and (iii) separated, with a dyke separating ponds from forest. The variations in shrimp yield of integrated and associated systems, that is, mixed systems, are attributable to water exchange, % water surface, primary production, stocking of post-larvae, leaf litter fall and decomposition, species, cover and age of mangrove, and predators. Leaf litter from all mangrove species except Nipa palm adversely affect water quality. Leaf composition and decomposition rate vary between species; submersed leaves decompose faster. Low concentrations of decomposing leaves of certain species temporarily boosted shrimp growth. Shrimp yield has been found to be highest in ponds with 30-50% mangrove cover, but remained <400 kg ha-1 year-1, if not fed timber production peaked at 55% mangrove cover (about 10 m3 ha-1 year-1). Annual benefit-cost ratio was better in integrated systems than in associated systems, but one study found the reverse in a long-term computation. An integrated mangrove-shrimp farm of 4 ha may provide farmers with a decent livelihood in Vietnam, if contracts do not restrict recommended practices to keep water quality within the limits acceptable for shrimp. Separated systems, where mangroves are fully connected to open water, have more potential to contribute to ecological, economic and social sustainability. Enhancing the economic returns by capitalizing on ecosystem services through carbon credits and organic certification, will require support for initial investment and clustering of farms. [ABSTRACT FROM AUTHOR]

In the Mekong Delta coastal zone, decision makers must weigh trade-offs between sustaining the shrimp sector and thus ensuring economic development, while also promoting sustainable, environmentally friendly practices and planning for climate change adaptation. This study investigates future scenarios for development of shrimp aquaculture using a spatially explicit, agent-based model (ABM) simulating farmers' production system choices. A role playing game (RPG) with farmers was used to calibrate and validate the model. Four scenarios, representing different visions of aquaculture in the next 15 years, were elaborated with decision makers before discussing the different outputs of the model. Iterative consultation with farmers helped to fine-tune the model and identify key parameters and drivers in farmers' decision-making. The recursive process allowed us to construct a model that validly represents reality. Participants stated that use of the RPG improved their insight for planning. Results of the scenarios indicate that (i) intensification of production is unsustainable, (ii) market-based incentives are too limited to stimulate development of an integrated mangrove–shrimp production system and (iii) climate change will cause rapid decline of production in the absence of adaptation measures. RPG appeared to be a valuable method for formalizing local farmers' knowledge and integrating it into the planning approaches used by decision makers. The ABM, thus, can also be considered a medium or communication tool facilitating knowledge-sharing between farmers and decision makers. [ABSTRACT FROM AUTHOR]

The development of shrimp farming in Vietnam has eroded the social-ecological resilience of the coastal ecosystem. Recent literature supports the idea that integrated mangrove-shrimp production systems can contribute to rebuilding this resilience in the Mekong Delta. Two experts panels, international and Vietnamese, were consulted to validate and weight drivers identified from literature that enable or constraint farmers to shift from extensive production system to integrated mangrove-shrimp system or to continue such integrated system. Though a combination of drivers is needed to enhance changes, two sets of drivers were given the highest weight. Experts considered the ecosystem function of the mangrove an enabling driver pushing farmers to plant mangrove in order to improve the pond's water quality and limit disease outbreaks. They perceived the drivers related to the current regulatory framework as constraining because these limit the financial return associated with integrated mangrove-shrimp systems. The analysis indicates that the adoption of these integrated systems requires more equitable distribution of benefits from shrimp and timber production between farmers and other stakeholder in these value chains. We recommend to develop a regulatory framework that can optimize the financial benefits of the integrated mangrove-shrimp production systems for farmers. [ABSTRACT FROM AUTHOR]

To reduce disease impact, Philippine farmers developed the green-water (GW) system, which has been spreading rapidly since 2008. In the most applied GW-system, the shrimp pond receives water from a reservoir stocked with tilapia. We collected financial data on GW and non-GW systems from farms having similar management and environmental context. All farms had more than one pond; the average pond area was < 1 ha, and total pond areas per farm ranged from 1.4 to 139 ha. The total variable and fixed costs per ha of shrimp pond were not different for GW and non-GW farms, but on GW farms the cost per kg of shrimp produced was lower. The latter was higher than the 2009 market price of 30 g shrimp for non-GW farms mainly. In GW farms the cost of seed was lower, and survival rates and individual shrimp weights at harvest were higher for an equally long culture period. [ABSTRACT FROM AUTHOR]

Bioeconomic modeling was used to evaluate traditional and extensive shrimp production in the Mahakam Delta and impacts of adopting Better Management Practices (BMP) for semi-intensive and integrated mangrove-shrimp culture. Modeling outcomes indicate that traditional production is not financially viable, failing to generate a positive 10-year Internal Rate of Return (IRR). Such practices persist in the Mahakam Delta as capital costs have been depreciated against past financial returns, input costs are negligible, risks are minimal, opportunity costs are low and options to intensify production have been retained by producers. Returns from BMP-guided semi-intensive culture (20% IRR) are marginally higher compared to extensive culture but entail a 10-fold increase in operating costs and greater risks. Integrated mangrove-shrimp production gives a reasonable IRR (53%) but costs remain high, management demanding and risks uncertain. Risk adverse operators with short-term leases may favor traditional and extensive practices. Sustainable intensification, allied to social capital development and rehabilitation of mangrove ecosystem services and environmental flows, is needed to reconcile multiple demands. [ABSTRACT FROM AUTHOR]

This study aims to update the typology of shrimp farms in a province of the Mekong Delta''s coastal area. We analyzed technical and economic characteristics of 170 farms using factor and cluster analysis on the different variables collected during the survey. This allowed us to characterize four different shrimp production systems: intensive commercial and intensive family farms, and the more extensive brackish water polyculture and rice¿shrimp farms. The systems differed in their level of intensification, diversification and origin of labor. Labor efficiency was higher in intensive than in extensive farms. The difference in technical practice affected the farm economy and specifically its operational monetary cost which was 25¿45 times higher in intensive commercial farms than in brackish water polyculture and rice¿shrimp farms, respectively. The intensive commercial farms were significantly less affected by virus outbreak than the extensive brackish water polyculture farms. This last shrimp production system presented a very low shrimp yield but a higher capital use efficiency than intensive commercial farms. Rice¿shrimp farms, which are located in a specific agro-ecological environment, presented average sustainability characteristics and an average disease occurrence. Results show that technological investments can reduce the vulnerability to disease outbreak and thus reduce the risk usually associated with shrimp farming. [Copyright &y& Elsevier]

The use of serious games in the governance of natural resources and the environment is progressively increasing and includes games used for research and data collection, teaching and training, and fostering a change of practices. However, this diversity remains underexplored and underreported. In view of a growing interest in the use of serious games in natural resource and environmental governance, the absence of discussions about how differences in intended use and delivery influence the performance, assessment, and outcomes of games is problematic. Here we present an inventory, and a description, of such different uses then, by focusing on serious games used as interventions, we discuss when, and how, games could be used to generate learning and social learning. To that end we use a narrative review of selected literature, and insight from research on social learning, to develop an inventory of game use, and within that inventory we conceptualize the use of serious games as a social learning intervention. Also, by means of an illustrative case of a serious game (developed as part of the Assessing the Learning Effects of Games on Attitude of Stakeholders toward Sustainable Shrimp Farming – ALEGAMS research project) we reflect on a few key aspects of game use. We suggest that developing a serious game needs several iterations and, although the learning outcomes can be assessed, the impact of games aiming at changes in current practice and policy will likely fall beyond the timespan of usual project periods. This is something future research should consider as it has implications for the research design and methodology. [ABSTRACT FROM AUTHOR]

Vietnam is the largest producer for the export of striped catfish. Traditionally striped catfish production in the Mekong Delta took place in integrated agriculture-aquaculture systems, but has shifted recently to intensive systems to meet increasing export demands. A recent study quantified the environmental impact of intensive striped catfish production in Vietnam. Another did the same for integrated systems. Both studies used life cycle assessment, covered similar environmental impact categories, and were roughly matched in the production stages included. However, an environmental comparison of both systems has not been made so far. The objective of this paper is to make a comparative life cycle assessment of striped catfish production in intensive and integrated systems. The comparison was based on existing life cycle assessments on these systems, but their methodological choices and data had to be aligned. The results show that striped catfish production in intensive systems contributes considerably more to seven of the nine assessed impact categories (global warming, ozone depletion, acidification, eutrophication, photochemical oxidation, human toxicity, freshwater ecotoxicity, marine aquatic ecotoxicity, fossil depletion). Only contributions to eutrophication and freshwater ecotoxicity were higher for the integrated systems than for the intensive systems. In both systems, grow-out fish farming contributes most to eutrophication and freshwater ecotoxicity, whereas feed production contributes most to all other impact categories. The environmental performance of integrated striped catfish production is convincingly better in most impact categories. This raises questions about whether (elements of) these systems can be used to mitigate the environmental impact of intensive striped catfish production. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

We contend there are currently two competing scenarios for the sustainable development of shrimp aquaculture in coastal areas of Southeast Asia. First, a landscape approach, where farming techniques for small-scale producers are integrated into intertidal areas in a way that the ecological functions of mangroves are maintained and shrimp farming diseases are controlled. Second, a closed system approach, where problems of disease and effluent are eliminated in closed recirculation ponds behind the intertidal zone controlled by industrial-scale producers. We use these scenarios as two ends of a spectrum of possible interactions at a range of scales between the ecological, social, and political dynamics that underlie the threat to the resilience of mangrove forested coastal ecosystems. We discuss how the analytical concepts of resilience, uncertainty, risk, and the organizing heuristic of scale can assist us to understand decision making over shrimp production, and in doing so, explore their use in the empirical research areas of coastal ecology, shrimp health management and epidemiology, livelihoods, and governance in response to the two scenarios. Our conclusion focuses on a series of questions that map out a new interdisciplinary research agenda for sustainable shrimp aquaculture in coastal areas. [ABSTRACT FROM AUTHOR]