This study assesses and identify major factors of social capital that affect the use of trade credit among shrimp farmers and how these contribute to and affect the profits of households in coastal provinces of the Mekong Delta, Vietnam. Data was collected through observations, informal discussions, and interviews with 364 shrimp farmers from the Ca Mau, Bac Lieu, Ben Tre and Tra Vinh provinces. The Probit and Tobit regression models were applied to analyze and evaluate the effect of social capital on the use of trade credit and the amount of trade credit used by farmers. The results show that many social capital factors affect the use of trade credit by shrimp farmers in the investigated areas, including in descending order of importance: profit, wholesale agents, colleague-friend-family line-neighbor, and trust. Besides the factors above, other factors such as agricultural land value, households’ income, distance, experiences in shrimp production, households’ assets, savings, profits of the previous crop, and the average household income had also an effect on trade use and amount of trade credit used by shrimp farming households. 

This study assesses the sustainability of intensive rice monocropping (IRM) and integrated rice-fish (IRF) farming in the Vietnam Mekong Delta, through systems analysis. Stakeholder (SH) consultations and a literature review were conducted to construct a Causal Loop Diagram (CLD), visualising the connections and effects of the two farming strategies across environmental, economic and social domains. 42 SHs, including farmers and scientists, assessed the impact of IRM and IRF on 42 interlinked CLD variables using a 5-point scale (-2 to 2). The SHs' scores were used to assess the farming strategies impact on 18 ecosystem services (ES) and the fulfilment of nine sustainable development goals (SDGs). The results show that IRM would have a negative impact on 14 ES, while IRF would have a positive impact on 17 ES. IRM was perceived to primarily have positive impacts on the rice yield and flood protection through an increased use of high dikes and agrochemicals, which however also was the main causes of the negative impacts on several other ES. IRF was perceived to have a positive effect on all SDGs, while IRM would only contribute to two and move away from seven SDGs. It is concluded that IRF provide a more sustainable alternative to IRM because it strengthens physical, ecological and social connections for an enhanced use of interlinked ES. This contributes to an increased productivity, farmers profit and wellbeing. IRF was also perceived to increase farming systems resilience, which is important for adapting to ongoing climate change and upstream dams.

Cartap hydrochloride (CH) is commonly used to control insect pests in the Mekong Delta, and this study assesses the effects of CH (1%, 10%, and 20% of the median lethal concentration at 96 hr value) on brain cholinesterase activity, food intake, feed conversion rate, and growth of silver barb (Barbonymus gonionotus) under laboratory conditions. The inhibition of the acetylcholinesterase activity increased with both concentration and time, reaching its peak 9 hr after exposure. After 96 hr, the inhibition remained at 10.4% in fish exposed to the lowest concentration and at 18.2% and 19.9% in fish exposed to the two highest concentrations. After 48 hr, the fish were placed in clean water, but the inhibition levels at the two highest concentrations still remained at 20% until Day 7, and only recovered fully after 14 days. The feed intake was similar between the control and all treatments, but the fish exposed to CH had higher feed conversion ratio than the fish in the control during the first 30 days. This indicates an increased stress in the exposed fish and that more energy was used for detoxification. As a result, fish in the control had gained most in weight after 60 days, whereas fish exposed to the highest level of CH had gained the least, and there was a significant effect of CH on fish growth. It is concluded that expected water levels of CH from doses commonly sprayed on rice fields may affect the health of fish in these habitats, and the use of CH should be limited, as it may negatively affect healthy fish production in the Mekong Delta, Vietnam.

This study assessed the effects of fenobucarb (F) (1%, 10%, and 20% of the LC50-96h value) on the brain cholinesterase (AChE) activity, food intake (FI), feed conversion rate (FCR), and growth of silver barb (Barbonymus gonionotus, Bleeker, 1849). It also assessed the AChE inhibition levels that cause the abnormal swimming, behavior, and mortality of silver barb and how the feeding regime affects the recovery rate of the AChE activity. The results showed that the brain AChE inhibition increased with the F concentrations. It peaked after nine hours, at 73.6% and 79.7% for the two highest concentrations, and then the AChE activity started to recover. After 96 h, the inhibition level was still 11.8% in the fish exposed to the two lowest concentrations and 30.5% in the fish exposed to the highest concentrations. Even when placed in clean water, the inhibition level in the fish that were exposed to the highest concentrations and only fed every third day was 32% after 14 days. Although there were no differences in the feed intake at any time, the fish exposed to F had a higher FCR and a lower specific growth rate and weight compared to the control fish at the later stages of the experiment. Thus, although the use of F in rice farming in the Mekong Delta may not lead to direct fish kills, it impacts the growth and health of the fish, which could have negative implications for wild fish populations and the long-term production of healthy fish in the Mekong Delta.

This study compares the food-production efficiencies of integrated rice-fish farming and rice monoculture and evaluates how these farming systems contribute to sustainable food production in the Mekong Delta. The study explores how food-production efficiencies are influenced by the systems’ ecological connectivity by comparing more integrated systems that apply integrated rice-fish farming and integrated pest management (IPM) with less integrated systems farming only rice. Rice-fish farmers with plenty of fish had significantly higher rice yields than farmers with less or no fish, especially during the second crop when the rice was grown together with the fish. A positive correlation between the fish and rice yields, indicated synergistic effects between the fish and rice, due to strengthened ecological connectivity and trophic interactions within the rice-field ecosystem. Overall, rice-fish farmers had higher rice yields than rice farmers, despite using lower amounts of fertilizers and pesticides. They also had lower rice production costs compared to rice farmers, partly because the fish helped fertilize the rice and control rice pests. They had a significantly higher profit and benefit cost ratio than rice farmers because of lower production costs, and high rice and fish yields. The results indicate that food-production efficiencies in the Mekong Delta can be enhanced through diversification and increased ecological connectivity, leading to a more efficient use of rice field ecosystem services that support a long-term and healthy production of food.

This study assesses farmers’ perceived impact of high-dikes on rice and fish yields, use of synthetic fertilizers, water quality, fish diversity, and inflow of nutrient-rich water and sediments in the Mekong Delta. Interviews were conducted with 89 farmers from three districts in the An Giang province, of which 69-98% of the agricultural land is covered by high-dikes. Only 57% of the farmers felt that the rice yields had increased after the construction of high-dikes. 93% of respondents perceived that the inflow of nutrient-rich water and sediments had decreased, and 99% felt that the use of synthetic fertilizers had increased by 26-37% after the construction of high-dikes. 94% of all farmers felt that high-dikes had impacted on the aquatic environment and water quality, which was perceived to have decreased from good to poor quality. The wild fish yield and fish diversity were estimated to have decreased by 68-83 and 75-81%, respectively, and had decreased most in Cho Moi, followed by Phu Tan and Chau Phu districts. It is concluded that high-dikes have helped to increase rice yields in some areas, but at the expense of decreased natural fertilization, water quality, fish diversity and yields, which all impact on the farmers’ profit and well-being.

Drawing on collective experience from ten collaborative research projects focused on the Global South, we identify three major challenges that impede the translation of research on sustainability and resilience into better-informed choices by individuals and policy-makers that in turn can support transformation to a sustainable future. The three challenges comprise: (i) converting knowledge produced during research projects into successful knowledge application; (ii) scaling up knowledge in time when research projects are short-term and potential impacts are long-term; and (iii) scaling up knowledge across space, from local research sites to larger-scale or even global impact. Some potential pathways for funding agencies to overcome these challenges include providing targeted prolonged funding for dissemination and outreach, and facilitating collaboration and coordination across different sites, research teams, and partner organizations. By systematically documenting these challenges, we hope to pave the way for further innovations in the research cycle.

Multi -actor labs (MALs), a form of real -world social experiments, were implemented in three coastal -rural regions in France (Charente River Basin), Spain (Mar Menor), and Greece (South-West Messinia) to better assess and tackle coastal -rural interactions that govern local sustainability challenges, such as water use conflicts and biodiversity degradation. The MALs used participative methodologies based on systems thinking and transition management. Stakeholders were continuously engaged in a series of workshops to co -produce knowledge, reach a common understanding of the sustainability challenges and issues at stake, and co -design solutions in the form of a roadmap for sustainable transitions in coastal -rural regions. This paper evaluates MALs to provide examples of successful sustainability transition experiments based on the outputs produced, outcomes achieved, and processes used in the three coastal, rural regions.

This study evaluates the effect of different diets supplemented with vitamin solutions on Pangasius catfish broodstock reproduction, growth performances, and the survival rates of fish larvae and fingerling. The growth and reproductive performances of breeders fed with different test diets showed significant differences among the six tested diets (p < 0.05). The highest final body weight (FBW), weight gain (WG), daily weight gain (DWG), specific growth rate (SGR) of broodstock, and survival rate of Pangasius fingerlings were found in Treatment 5, which contained 0.6% H-OVN mixed with 12.6% algal oil, and Treatment 3, which contained 0.6% vitamin premix H-OVN. The average gonadosomatic index (GSI), relative fecundity index (RFI), fertilized eggs, hatching rates of eggs, and survival rate of fingerlings was 9.1 ± 2.8 (6.7–12.8%), 133,224 ± 39,090 (104,267–199,512 eggs/kg), 77.9 ± 22.2 (62.2–93.6%), and 45.3 ± 17.4 (22.0–66.3%), respectively. The findings of this study showed that the diet containing 35% CP contents supplemented with 0.6% vitamin premix H-OVN mixed with algal oils showed the highest results in terms of growth, reproductive performance indices, and survival rates of Pangasius catfish fingerlings.

This study makes an ecological economic comparison between three different rice farming strategies in the Mekong Delta. Interviews were made with 30 farmers with two crops of rice and low dikes (2RLd), 30 farmers with three crops of rice and high dikes (3RHd) and 18 farmers with two crops of rice and one crop of fish (2RF). 2RF farmers had the highest annual net income and benefit cost ratio, because of low production costs and high yields of rice and fish. 2RLd farmers had the lowest annual net income. 3RHd had the highest annual rice yield, but also used the highest amount of rice seeds and agrochemicals, generating the lowest benefit cost ratio. Most farmers (70%) preferred two crops because of a higher production efficiency. High dikes and frequent use of pesticides and fertilizers were seen to decrease the water and rice quality, connectivity and biodiversity in farms with three crops. It is concluded that rice farming with two crops, and especially if integrated with fish and applying IPM, provides a sustainable alternative to rice farming with three crops and high dikes, because it makes use of the high connectivity within the rice-field ecosystem for an efficient production of healthy food through increased recycling of nutrients and  natural pest control mechanisms.