Lab-based meat or cultivated meat (CM) is produced by growing edible animal cells using cellular agriculture techniques and eliminates the need to farm or capture live animals. Given the depleted state of global fisheries and adverse environmental impacts associated with aquaculture, CM systems may be particularly suited to help meet the rising demand for blue foods, especially high-value and luxury species, sustainably. Despite growing research into CM products and their potential to lower the environmental impacts associated with animal-based foods, the environmental performance of CM blue foods remains largely unknown. Here, we use life cycle assessment (LCA) to quantify the cradle-to-gate environmental impacts associated with three CM blue food products. We find that CM blue foods have a cumulative energy demand of 40–45 MJ kg^–1, emit 2.1–2.3 kg of CO₂ equiv kg^–1 (global warming), require 1.1–1.6 m² a kg^–1 (land use), consume 97–152 L kg^–1 (water use), and contribute 0.9–1.3 g of P equiv kg^–1 and 0.9–1.1 g of N equiv kg^–1 (freshwater and marine eutrophication). These impacts are generally lower than those reported for cultivated farm animals and for conventionally produced analogous blue foods. However, results reveal potential for environmental trade-offs (e.g., higher water use) and underscore the need for multi-indicator environmental evaluation of novel foods.

Blue food—aquatic organisms fished or farmed in marine and freshwater areas, including fish, shellfish, and aquatic plants—make critical contributions to nutrition, livelihoods, and economies, and can have lower carbon footprints than other animal-source foods. While blue foods are increasingly discussed as part of climate change mitigation and adaptation, climate change also affects the feasibility, performance, and equity outcomes of blue food strategies, and evaluations of such strategies remain limited. Through an expert-driven, iterative process, we review 22 strategies through which blue foods may contribute to climate mitigation or adaptation, consolidating evidence on their potential effectiveness, feasibility, and associated trade-offs and synergies across sustainable development outcomes. The reviewed literature provides relatively good evidence for the mitigation potential of Decarbonizing production practices and Shift diets towards low-emission blue foods, and for adaptation benefits associated with Shift gear or target species. However, evidence across strategies remains uneven, highly context-specific, and in some cases limited. Trade-offs with sustainable development outcomes, risks of increasing vulnerability, and a persistent bias in research and policy towards technological innovation over systemic and societal change complicate evaluation and implementation of blue food climate strategies. No single strategy emerges as transformative in isolation. Rather, findings suggest that context-appropriate portfolios of strategies, implemented in combination, may offer complementary and synergistic benefits. Further research and evaluation are needed to substantiate claims about the transformative potential of blue foods, including systems-based analyses and targeted assessments of individual strategies, with particular attention paid to capacity-strengthening measures and equity in design and implementation.

Purpose: Ocean alkalinity enhancement (OAE) is considered a promising marine carbon dioxide removal (mCDR) option and may contribute to climate change mitigation. Life cycle assessment (LCA) is used to assess OAE environmentally but faces limitations in capturing marine impacts. Improving the assessment of OAE in LCA requires a detailed understanding of its marine environment impact pathways to develop sub-compartmentalised and regionalised characterisation factors (CFs). We demonstrate how such pathways can be identified. Methods: We build on Woods et al. (2021), who propose a qualitative framework to identify key components of impact pathways, and Richter et al. (2024), who provide guidance on framework development in a multidisciplinary context. We develop a methodological approach that allows to qualitatively identify the marine environmental impact pathways of OAE and determine which components are integrated in LCIA models or missing, as an initial phase toward developing CFs for life cycle impact assessment (LCIA). Results and discussion: Our methodological approach includes: (1) the selection of literature on OAE and its impacts on marine ecosystems; (2) the identification of the marine elementary flows in the life cycle inventory and the fate, exposure, and effect processes; (3) the inputs from LCIA, oceanography, and technology experts; (4) the review of LCIA models to examine which elements of the marine environmental impact pathways are represented or lacking; (5) the definition of research priorities to advance the assessment of OAE’s environmental impacts within LCA. We identified three impact categories associated with OAE marine environmental impacts pathways: marine ecotoxicity, marine eutrophication, and ocean acidification. Existing LCIA models only partially capture these pathways and require adaptation for assessing comprehensively OAE. Research priorities include conducting additional experiments on the ecotoxicological and eutrophic effects of OAE deployment in marine environments, and the effect of added alkalinity on a broader range of marine calcifiers. Several of our recommendations are also relevant to enhance marine technologies’ assessments in LCA more broadly, such as improving the ocean’s representation in models, modelling direct release to offshore marine waters, and broadening the elementary flows’ coverage for marine eutrophication. Conclusion: We present a methodology to identify marine environmental impact pathways of OAE, providing a first phase toward developing CFs. The methodological approach might be adapted to other marine technologies, where identifying impact pathways require a multidisciplinary approach that combines the LCA field with oceanography and engineering expertise.

Life cycle assessment (LCA) of shrimp aquaculture is hampered by widely divergent results, with reported impacts varying by more than fiftyfold across key categories. This systematic review of 16 peer-reviewed LCAs provides quantitative evidence that much of this divergence is driven by analytical choices rather than on-farm performance: In this case study covering 37 farming cycles, methodological differences in shrimp LCAs induced larger changes in global warming estimates for identical farm data compared to different farming practices. This issue is compounded by a lack of transparency, with only five of the 16 studies providing sufficient data for full reproducibility. We find that this methodological dominance is amplified by analytical blind spots, as most studies neglect critical environmental pressures such as land use change, biodiversity loss, and antibiotic use. To build a robust and comparable evidence base, we recommend representative studies, specific methodological harmonisation, mandatory inclusion of neglected impact categories, and improved reporting transparency. These improvements are essential for LCA to accurately guide the sector towards more sustainability.

Antimicrobial resistance (AMR) demands collective action to reduce and mitigate its threats. The Quadripartite collaboration of the World Health Organization (WHO), Food and Agriculture Organization of the United Nations (FAO), United Nations Environment Programme (UNEP) and World Organization for Animal Health (WOAH) has led development and implementation of National Action Plans (NAPs) that describe approaches each country will take to tackle AMR. All antimicrobial users and sectors should be included, and the Quadripartite encourages a One Health approach. Aquaculture has received mixed coverage in NAPs: Here, we argue why aquaculture requires special consideration. Aquaculture is a diverse, global collection of industries and activities, with heterogeneity in systems and species greatly exceeding terrestrial food-animal production, with products traded internationally in huge volumes. Almost 6 % of global total antibiotic usage is estimated to be applied in aquaculture, with per-biomass quantities in some species exceeding usage in human and terrestrial food-animals. The watery nature of aquaculture interconnects it with other One Health compartments: humans, other animals and the wider environment. Rapid industry growth challenges relatively detached stakeholders such as regulators and NAP creators to remain abreast of changing practices, whilst support capabilities and capacity, e.g., health services, typically lag behind growing needs. To integrate aquaculture effectively into next-generation NAPs, ensuring policies cover the One Health spectrum, NAP creators need to recognise the diversity of aquaculture and initiate engagement across associated value chains, especially health service providers. Disentangling the industry can assist formulation of realistic policies for heterogenous contexts and identify pathways to implementation. Resource allocation must be appropriate and include relevant government departments, whilst improved ways to track and monitor AMR, including those international activities that impact AMR domestically, through suitable data collection are key to monitoring and evaluating policies. Better NAPs are crucial to addressing AMR and this coordinated global approach provides our best opportunity for success.

Animal-source foods provide essential nutrients for humans, however, the use of nutrient-dense (i.e., high in nutrients but low in calories) and digestible resources for animal feeds is controversial as it may reduce the net contribution of farmed animals to global food supply, and hence to food security. Redirecting resources edible by humans to direct consumption as food can increase resource use efficiency and food supply, however, what can be considered as edible by humans is context dependent. The objective of the present study is to assess the net contribution of ten contrasting tilapia production systems from eight different countries to the supply of nutrients of importance for human health. To do so we calculated the human-edible nutrient conversion ratio (HeNCR), which is the human-edible nutrients in the inputs (feed) divided by the human-edible nutrients in the outputs (animal products) of the systems. We showed that tilapia systems can be net producers of proteins, but that in general, much more human edible micronutrients (5 to 175 times) and EPA + DHA (about 7 times) were in the feed used than in the fish produced. Four scenarios combining different definitions for feed and fish edibility were tested to explore the effect of different dietary changes on the performances of the tilapia systems. Scenario analysis revealed that the direct use of edible ingredients as food generates more nutrients than the consumption of fish. Consumers’ preferences, and therefore our definition of what is edible, may have to evolve in order to maximize food resource use.

As climate impacts worsen, novel technologies to draw down atmospheric carbon are gaining attention. One such approach is ocean-based carbon dioxide removal (OCDR). However, the potential environmental side-effects of large-scale OCDR deployment remain understudied. Here, we present a systematic literature review of the life cycle assessments (LCAs) of OCDR approaches. We find that current OCDR LCAs have a limited scope, often overlook environmental impacts beyond global warming, and that LCA as a method is currently limited in capturing aquatic impacts. We provide several recommendations for future work, such as using a functional unit of storing atmospheric carbon over a specified time horizon and in a specified medium, performing cradle-to-grave analysis, including more (marine) environmental impacts, and estimating uncertainties. We also emphasise the need to develop the LCA methodology further for better assessing marine environment impacts.

The intensification of aquaculture industries around the globe has led to increased susceptibility and exposure to diseases. To ensure the well-being of animals and the profitability of the industry, many aquaculture farms resort to antibiotic treatments. However, with the increasing presence of antimicrobial resistance (AMR), it has become important to regulate and limit the use of antibiotics, especially in animal production and regarding the antibiotics that are deemed as critically important for human health by the World Health Organization (WHO). This review describes how AMR mitigation strategies have developed over time in international settings and how they relate to aquaculture. Furthermore, we analyzed how different countries and regions abide by these statutes, as well as the antibiotic standards from a selection of certification schemes. Our results show that the role of aquaculture has been inexplicitly addressed in international guidance documents and that there is a need to further increase the activities of aquaculture operations in combating AMR, with an emphasis on alternatives to antibiotic use. We also found that most countries and regions allow the highest priority-, or critically important antibiotics in aquaculture, which could have detrimental effects on animal, environmental, and public health. As a result, most countries fail to comply with the recommendations and standards set by international organizations and certification schemes.

Aquaculture is a crucial sector for Egyptian food production, providing a cheap source of animal protein while securing income and employment for a substantial part Egypt's population. Nile tilapia (Oreochromis niloticus) is the most commonly produced fish, usually farmed in earthen ponds around the Northern Delta Lakes. A common practice among farms is to fertilize ponds with chicken manure (CM) in order to increase nutrient levels and promote phytoplankton, consumed by the fish. However, with reports of use of antibiotics in Egypt's poultry sector, and that CM contains residues of antibiotics, antibiotic resistant pathogens and antibiotic resistance genes (ARGs) are production benefits large enough to compensate a potential health hazard?

Using production data from 501 aquaculture farms and fish pond sediment from 28 ponds we evaluated potential benefits in yields and profitability for farms using CM for fertilization, and used qPCRs to screen sediments for three antibiotic resistance genes coding for resistance to the most commonly used antibiotics in the poultry sector. The analysis showed no significant benefits to fish yields or profitability in farms where CM was applied, but a risk of significantly increased nutrient loads. Meanwhile, we detected increased abundances of tetA and tetW resistance genes in fish pond sediment where CM was applied. With the risk of disseminating ARGs and causing eutrophication of local waterways, we recommend that Egyptian tilapia pond farmers refrain from using CM and adopt best management practices for increasing farm profitability in order to to reduce environmental and health hazards.

A circular economy is considered one way to reduce environmental impacts of human activities, by more efficient use of resources and recovery, resulting in less waste and emissions compared to linear take-make-dispose systems. Muscat et al. developed five ecological principles to guide biomass use towards a circular economy. A few studies have demonstrated environmental benefits of applying these principles to land-based food systems, but to date, these principles have not been explored in aquaculture. The current study expands on these principles and provides a narrative review to (i) translate them to aquaculture, while identifying implications for the main species and production systems, and (ii) identify the main pathways to make aquaculture more circular. We show that the underlying concepts of the ‘safeguard’, ‘entropy’, and ‘recycle’ principles have been well researched and sometimes well implemented. In contrast, the ‘avoid’ and ‘prioritise’ principles have been explored much less; doing so would provide an opportunity to decrease environmental impacts of aquaculture at the food-system level. One example is prioritising the production of species that contribute to food and nutrition security, have low environmental impacts and thinking at wider food system scale to avoid feed-food competition in aquaculture. We identified six priorities that could make aquaculture more circular: (i) increase production and demand for the most essential species, (ii) decrease food loss and waste at farm and post-harvest stages, (iii) support nutrient recycling practices at multiple scales, (iv) adapt aquafeed formulations, (v) inform consumers about benefits of species of low trophic levels and other environmentally friendly aquatic foods, and (vi) address urgent research gaps.