Comparison of Asian Aquaculture Products by Use of Statistically Supported Life Cycle Assessment

Comparative assessment of Chinese mitten crab aquaculture in China: Spatiotemporal changes and trade-offs

The increasing human demand for high-quality animal protein has provided impetus for the development of aquaculture. Chinese mitten crab (Eriocheir sinensis) is a catadromous species rapidly being cultured in China but scientific literature documenting its life cycle environmental and economic consequences remains scarce. This study aims to address this gap by examining the spatio-temporal evolution of crab aquaculture in China since the 2000s and evaluating the environmental and economic characteristics along its life-cycle stages: megalopa, juvenile crab, and adult crab cultivation. The geostatistical analysis shows a more dispersed pattern of crab aquaculture nationally as crab grows, with coastal provinces that have brackish water for megalopa cultivation but wider spatial coverage for juvenile and adult crab cultivation. Our findings reveal that the production of 1 ton of live-weight crab results in 7.65 ton of CO2 equivalent of greenhouse gas emissions, surpassing previous estimates for finfish fish production by approximately 50%. Most environmental pressures occur during the adult crab cultivation stage, with significant contributions from upstream processes such as electricity and feed production. By comparing between different production systems, our study shows that crab aquaculture in lake systems performs better than pond systems in terms of most global environmental impact categories and economic considerations. This work contributes to the existing literature by elucidating the spatio-temporal changes of crab aquaculture boom in China and constructing a representative life cycle data pool that broadens the benchmark knowledge on its environmental and economic characteristics. We highlight the trade-offs between environmental and economic performance as well as the balance between global and local environmental impacts to promote sustainable growth in the aquaculture industry.

More Than Fish-Framing Aquatic Animals within Sustainable Food Systems

Aquatic animals are diverse in terms of species, but also in terms of production systems, the people involved, and the benefits achieved. In this concept piece, we draw on literature to outline how the diversity of aquatic animals, their production, and their consumption all influence their impact within the food system. Built on evidence from an array of reductionist and non-reductionist literature, we suggest that food systems researchers and policymakers adapt current methods and theoretical frameworks to appropriately contextualise aquatic animals in broader food systems. We do this through combining current understandings of food systems theory, value chain, livelihoods, nutritional outcomes, and planetary boundaries thinking. We make several claims around understanding the role of aquatic animals in terms of nutritional output and environmental impacts. We suggest a need to consider: (1) the diversity of species and production methods; (2) variable definitions of an "edible yield"; (3) circular economy principles and the impacts of co-products, and effects beyond nutrient provision; (4) role of aquatic animals in the overall diet; (5) contextual effects of preservation, preparation, cooking, and consumer choices; (6) globalised nature of aquatic animal trade across the value chain; and (7) that aquatic animals are produced from a continuum, rather than a dichotomy, of aquaculture or fisheries. We conclude by proposing a new framework that involves cohesive interdisciplinary discussions around aquatic animal foods and their role in the broader food system.

Advantage of Species Diversification to Facilitate Sustainable Development of Aquaculture Sector

Intensified agrochemical-based monoculture systems worldwide are under adoption to meet the challenge of human population growth and the ever-growing global demand for food. However, this path has been opposed and criticized because it involves overexploitation of land, monoculture of few species, excessive input of agrochemicals, and adverse impacts on human health and the environment. The wide diversity among polyculture systems practiced across the globe has created confusion over the priority of a single strategy towards sustainable aquaculture development and safer products. Herein, we highlight the significance of polyculture and integrated aquaculture practices in conveying the successful transition of the aquaculture industry towards sustainable development. So far, the established thought is that the precise selection of aquatic species and a focus on compatible and complementary species combinations are supposed to facilitate rapid progress in food production with more profitability and sustainability. Therefore, the advantages of species diversification are discussed from an ecological perspective to enforce aquaculture expansion. This account asserts that a diverse range of aquaculture practices can promote synergies among farmed species, enhance system resilience, enable conservation, decrease ecological footprints, and provide social benefits such as diversified income and local food security.

Intensification, regulation and diversification: The changing face of inland aquaculture in China

Trends in aquatic food consumption were matched against farm production surveys within Hubei province and compared to official production data and statistics. Surveys showed that consumer tastes were changing to a much broader aquatic food menu as their spending power increased. Traditional aquaculture species were becoming less profitable due to reduced profit margins as input costs increased and consumption preferences changed. Consequently, many producers were diversifying their production to meet local demand. Some farmers were also de-intensifying by reducing commercial aquafeed inputs and reverting to more traditional methods of dyke-crop culture to optimise trade-offs between input costs and labour, and manage their risk more effectively. In addition, analysis of local data showed that wholesale changes were occurring to aquaculture production as environmental protection legislation took effect which reduced the growing area for carps considerably.

Recirculating Aquaculture Is Possible without Major Energy Tradeoff: Life Cycle Assessment of Warmwater Fish Farming in Sweden

Seafood is seen as promising for more sustainable diets. The increasing production in land-based closed Recirculating Aquaculture Systems (RASs) has overcome many local environmental challenges with traditional open net-pen systems such as eutrophication. The energy needed to maintain suitable water quality, with associated emissions, has however been seen as challenging from a global perspective. This study uses Life Cycle Assessment (LCA) to investigate the environmental performance and improvement potentials of a commercial RAS farm of tilapia and Clarias in Sweden. The environmental impact categories and indicators considered were freshwater eutrophication, climate change, energy demand, land use, and dependency on animal-source feed inputs per kg of fillet. We found that feed production contributed most to all environmental impacts (between 67 and 98%) except for energy demand for tilapia, contradicting previous findings that farm-level energy use is a driver of environmental pressures. The main improvement potentials include improved by-product utilization and use of a larger proportion of plant-based feed ingredients. Together with further smaller improvement potential identified, this suggests that RASs may play a more important role in a future, environmentally sustainable food system.

Concerted Efforts Are Needed to Control and Mitigate Antibiotic Pollution in Coastal Waters of China

Antibiotics have been applied for decades and antibiotic pollution is of great concern due to the risk for promoting resistant genes. Human activities such as mariculture and land-based discharge can lead to the antibiotic pollution in coastal area and it is of importance to assess the pollution and risks of antibiotics in this area. In this mini-review, the pollution status of antibiotics in Chinese coastal waters is summarized and some perspectives are put forward for future efforts to mitigate the pollution.

Is Super-Intensification the Solution to Shrimp Production and Export Sustainability?

The government of Vietnam has selected shrimp production and exports as the pillars of rural economic development. The targets set depend on high yields through production intensification. International and national public research communities have raised production intensification concerns related to environmental and climate change challenges, such as saltwater intrusion, water pollution, disease outbreaks, mangrove destruction, and natural resource degradation. Social snags such as user right conflicts of water resources, food safety problems, tariff barriers, and attempts to taint the industry’s image by competitors also plague the industry. These give rise to the problem of certification and questions about the influence of standards on the small-scale farming sustainability in a competitive global environment. The questions asked are, how can one bring together small-scale shrimp farmers to comply with international standards? Can small-scale shrimp farming co-exist with super-intensive producers to bring about a sustainable and competitive industry? A proposed model to horizontally organize the limited resource farmers into cooperatives to vertically integrate with large-scale firms producing shrimp using super-intensive production methods shows small-scale farmers adopting super-intensive production methods that can generate higher yields, income, profits, and is more environmentally friendly and requires less water and land. The capital requirements are high for limited resource farmers. However, with the interest showed by banks in financing models that are appropriate for small-scale farms integrated with larger firms engaged in super-intensive production systems, along with government assistance, these small-scale shrimp producing units can attain higher levels of sustainability than the open, less intensive production systems.

Does the use of pre-calculated uncertainty values change the conclusions of comparative life cycle assessments? - An empirical analysis

In life cycle assessment (LCA), performing Monte Carlo simulation (MCS) using fully dependent sampling typically involves repeated inversion of a technology matrix for a sufficiently large number of times. As the dimension of technology matrices for life cycle inventory (LCI) databases grows, MCS using fully dependent sampling is becoming a computational challenge. In our previous work, we pre-calculated the distribution functions of the entire LCI flows in the ecoinvent ver. 3.1 database to help reduce the computation time of running fully dependent sampling by individual LCA practitioners. However, it remains as a question whether the additional errors due to the use of pre-calculated uncertainty values are large enough to alter the conclusion of a comparative study, and, if so, what is the odds of such cases. In this study, we empirically tested the probability of altering the conclusion of a comparative LCA due to the use of pre-calculated uncertainty values. We sampled 10,000 random pairs of elementary flows of ecoinvent LCIs (a_i and b_i) and ran MCSs (1) using pre-calculated uncertainty values and (2) using fully dependent sampling. We analyzed the distribution of the differences between a_i and b_i (i.e., a_i−b_i) of each run, and quantified the probability of reversing (e.g., a_i > b_i became a_i < b_i) or moderating the conclusion (e.g., a_i > b_i became a_i ≈ b_i). In order to better replicate the situation under a comparative LCA setting, we also sampled 10,000 random pairs of elementary flows from the processes that produce electricity, and repeated the same procedure. The results show that no LCIs derived using pre-calculated uncertainty values constitute large enough differences from those using fully dependent sampling to reverse the conclusion. However, in 5.3% of the cases, the conclusion from one approach is moderated under the other approach or vice versa. When elementary flow pairs are sampled only from the electricity-producing processes, the probability of moderating the conclusions increases to 10.5%, while that of reversing the conclusions remains nil. As the number of unit processes in LCI databases increases, running full MCSs in a PC-environment will continue to be a challenge, which may lead some LCA practitioners to avoid uncertainty analysis altogether. Our results indicate that pre-calculated distributions for LCIs can be used as a proxy for comparative LCA studies in the absence of adequate computational resources for full MCS. Depending on the goal and scope of the study, LCA practitioners should consider using pre-calculated distributions if the benefits of doing so outweighs the associated risks of altering the conclusion.

Nutritional Attributes, Substitutability, Scalability, and Environmental Intensity of an Illustrative Subset of Current and Future Protein Sources for Aquaculture Feeds: Joint Consideration of Potential Synergies and Trade-offs

Aquaculture is anticipated to play an increasingly important role in global food security because it may represent one of the best opportunities to increase the availability of healthy animal protein in the context of resource and environmental constraints. However, the growth and sustainability of the aquaculture industry faces important bottlenecks with respect to feed resources, which may be derived from diverse sources. Here, using a small but representative subset of potential aquafeed inputs (which we selected to highlight a range of relevant attributes), we review a core suite of considerations that need to be accommodated in concert in order to overcome key bottlenecks to the continued development and expansion of the aquaculture industry. Specifically, we evaluate the nutritional attributes, substitutability, scalability, and resource and environmental intensity of each input. On this basis, we illustrate a range of potential synergies and trade-offs within and across attributes that are characteristic of ingredient types. We posit that the recognition and management of such synergies and trade-offs is imperative to satisfying the multi-objective decision-making associated with sustainable increases in future aquaculture production.

Measuring the potential for sustainable intensification of aquaculture in Bangladesh using life cycle assessment

Aquaculture has only recently begun to make significant contributions to the global food system but is undergoing rapid growth and intensification. Identifying the most sustainable intensification options for aquaculture provides an opportunity to avoid some of the environmental pitfalls of agriculture and livestock production. Life cycle assessment is operationalized here as a tool to evaluate a range of environmental impacts resulting from the intensification of aquaculture production in Bangladesh and a subset of trade-offs among them. Intensifying aquaculture production results in multidirectional outcomes across different environmental impact categories. These findings are used to identify simple improvements in farm management practices that can make the intensification of aquaculture more sustainable.

Food production is a major driver of global environmental change and the overshoot of planetary sustainability boundaries. Greater affluence in developing nations and human population growth are also increasing demand for all foods, and for animal proteins in particular. Consequently, a growing body of literature calls for the sustainable intensification of food production, broadly defined as “producing more using less”. Most assessments of the potential for sustainable intensification rely on only one or two indicators, meaning that ecological trade-offs among impact categories that occur as production intensifies may remain unaccounted for. The present study addresses this limitation using life cycle assessment (LCA) to quantify six local and global environmental consequences of intensifying aquaculture production in Bangladesh. Production data are from a unique survey of 2,678 farms, and results show multidirectional associations between the intensification of aquaculture production and its environmental impacts. Intensification (measured in material and economic output per unit primary area farmed) is positively correlated with acidification, eutrophication, and ecotoxicological impacts in aquatic ecosystems; negatively correlated with freshwater consumption; and indifferent with regard to global warming and land occupation. As production intensifies, the geographical locations of greenhouse gas (GHG) emissions, acidifying emissions, freshwater consumption, and land occupation shift from the immediate vicinity of the farm to more geographically dispersed telecoupled locations across the globe. Simple changes in fish farming technology and management practices that could help make the global transition to more intensive forms of aquaculture be more sustainable are identified.

Quantified Uncertainties in Comparative Life Cycle Assessment: What Can Be Concluded?

Interpretation of comparative Life Cycle Assessment (LCA) results can be challenging in the presence of uncertainty. To aid in interpreting such results under the goal of any comparative LCA, we aim to provide guidance to practitioners by gaining insights into uncertainty-statistics methods (USMs). We review five USMs-discernibility analysis, impact category relevance, overlap area of probability distributions, null hypothesis significance testing (NHST), and modified NHST-and provide a common notation, terminology, and calculation platform. We further cross-compare all USMs by applying them to a case study on electric cars. USMs belong to a confirmatory or an exploratory statistics' branch, each serving different purposes to practitioners. Results highlight that common uncertainties and the magnitude of differences per impact are key in offering reliable insights. Common uncertainties are particularly important as disregarding them can lead to incorrect recommendations. On the basis of these considerations, we recommend the modified NHST as a confirmatory USM. We also recommend discernibility analysis as an exploratory USM along with recommendations for its improvement, as it disregards the magnitude of the differences. While further research is necessary to support our conclusions, the results and supporting material provided can help LCA practitioners in delivering a more robust basis for decision-making.

Environmental impact of non-certified versus certified (ASC) intensive Pangasius aquaculture in Vietnam, a comparison based on a statistically supported LCA

Pangasius production in Vietnam is widely known as a success story in aquaculture, the fastest growing global food system because of its tremendous expansion by volume, value and the number of international markets to which Pangasius has been exported in recent years. While certification schemes are becoming significant features of international fish trade and marketing, an increasing number of Pangasius producers have followed at least one of the certification schemes recognised by international markets to incorporate environmental and social sustainability practices in aquaculture, typically the Pangasius Aquaculture Dialogue (PAD) scheme certified by the Aquaculture Stewardship Council (ASC). An assessment of the environmental benefit of applying certification schemes on Pangasius production, however, is still needed. This article compared the environmental impact of ASC-certified versus non-ASC certified intensive Pangasius aquaculture, using a statistically supported LCA. We focused on both resource-related (water, land and total resources) and emissions-related (global warming, acidification, freshwater and marine eutrophication) categories. The ASC certification scheme was shown to be a good approach for determining adequate environmental sustainability, especially concerning emissions-related categories, in Pangasius production. However, the non-ASC certified farms, due to the large spread, the impact (e.g., water resources and freshwater eutrophication) was possibly lower for a certain farm. However, this result was not generally prominent. Further improvements in intensive Pangasius production to inspire certification schemes are proposed, e.g., making the implementation of certification schemes more affordable, well-oriented and facilitated; reducing consumed feed amounts and of the incorporated share in fishmeal, especially domestic fishmeal, etc. However, their implementation should be vetted with key stakeholders to assess their feasibility.