Inadequate seed supply remains a bottleneck for the expansion of the Macrobrachium rosenbergii production industry. Nevertheless, the limitation is not technical, and thus, we presumed that fragile production chains and economic feasibility might be the major issues. Therefore, we investigated the intensification as a way to improve the system's profitability and resilience. We have reported relevant costs and revenues of hypothetical hatcheries stocking 50, 100, and 140 larvae per L in clear water recirculating systems. A Monte Carlo simulation assessed the risks associated with development and management. Data showed that all hatcheries are profitable. Nevertheless, 100 and 140 larvae per L reached better economic results than 50 larvae per L. With less than 40% of the selling price, high‐density hatcheries covered their costs and became profitable. The Monte Carlo simulation demonstrated that high‐density hatcheries are more resilient to production and marketing oscillations. However, the use of 140 larvae per L requires greater investment and is more susceptible to production risks and instabilities. Therefore, 100 larvae per L is the most appropriate stocking density for M. rosenbergii hatchery in clear water recirculating systems. Additionally, the scaled production, the adoption of realistic selling price, diversification of products and markets may strengthen the production chain and hatcheries resilience.

Freshwater pond aquaculture is the prevailing fish culture system worldwide, especially in developing countries. The sustainability of such systems has not been assessed and it can be improved based on suitable scientific analyses. In the present study, we apply the emergy synthesis to assess the sustainability of lambari aquaculture, used as a model of freshwater pond monoculture in Brazil, to identify the key practices, and to propose changes to improve them towards sustainability. As a study model, nine semi-intensive lambari farms operating at three levels of management were evaluated: low (LC), moderate (MC) and high (HC) control. Results showed that the main inputs for LC were services (27–46%), feed (7–39%) and water (15–21%), while for the MC and HC farms, they were feed (35–49% and 17–48%, respectively) and services (33–39% and 26–36%, respectively). All farms required more than 60% of their emergy from purchased inputs, resulting in low emergy sustainability index (ESI = 0.1–0.5). Increasing juvenile productivity, using superficial water instead of springwater, controlling pond fertilization and replacing animal protein in diet composition by vegetable sources can lead systems to higher efficiency and resilience, increasing sustainability.

The Covid-19 pandemic has uncovered the foremost struggles of the twenty first century: social-economic inequality, global value chains, national security, and the environmental crisis. None of these seems novel, as many staged fiction dystopias have been predicting and warning mankind about the negative impacts of unsustainable consumption behaviors by displaying scenarios of exponential human population and economy growth. Several scientific tools for assessing sustainability have been developed to cover social, economic, and environmental aspects, however, most of them are simply used either separately or without a solid conceptual model supporting an epistemological construct to allow for deeper and scientific-based discussions on sustainability. This work presents a perspective about possible scenarios of the world's sustainability, based on a straightforward integrated framework for its quantification. The three capitals of sustainability, summarized as environmental sustainability, productivity and happiness are combined, based on the input-state-output model, and further plotted on a 3-axis graph. Eight different combinations of the three capitals show eight potential future worlds. The least desirable scenario, named “Ineffective,” depicts an environmentally unsustainable, unhappy and poor world, whereas “Paradise” is the utopia to be pursued: happy, environmentally sustainable and productive. Societies' decisions on taking action after quantitatively measuring and monitoring sustainability will be determinant in placing the world on a more developed and sustainable path, and the model proposed in this work can be useful in promoting discussions in this direction.

Freshwater pond aquaculture is the prevailing fish culture system worldwide, especially in developing countries. Climate change outcomes and inadequate environmental practices challenge its sustainability. This study applies emergy synthesis to assess the environmental performance of freshwater pond aquaculture in Brazil, aiming to identify and propose practices towards sustainability. As a study model, nine semi-intensive lambari farms operating at three levels of management were evaluated: low (LC), moderate (MC) and high (HC) control. Results showed that the main inputs for LC were services (27-46%), feed (7-39%), and water (15-21%), while for the MC and HC farms, they were feed (35-49% and 17-48%, respectively) and services (33-39% and 26-36%, respectively). All farms required more than 60% of their emergy from purchased inputs, resulting in low emergy sustainability index (ESI = 0.1-0.5). Replacing animal protein and oil on diet composition by vegetal sources, using superficial water instead of springwater, increasing juvenile productivity, and controlling pond fertilization can lead all systems to higher efficiency and resilience, increasing sustainability.