Aquaculture is undergoing a revolution of data-driven innovation. The rapid uptake of digital technologies in the sector contributes ever larger amounts of data that hold potential for improving decision making for aquatic food system sustainability. Realising the potential of digital tools and new data streams is, however, not inevitable. The current ecosystem of global and production-level digital aquaculture technologies and platforms is highly fragmented with a strong focus on private farm-level data for improving production efficiency, and limited publicly available data that can be used for social and environmental sustainability. Three scenarios for the future development of the aquaculture data ecosystem are possible (1) continued fragmentation; (2) centralisation, and (3) coordination in a federated ecosystem. Recognising a federated ecosystem as having the most potential for contributing to food system sustainability we provide three priority areas for improving data coverage, sharing and integration between and among farm-level and global platforms.

Bangladesh has made significant progress in social and economic development in recent years, but micronutrient deficiencies and poor dietary diversity remain a significant challenge. This paper developed five scenarios to explore futures of fish supply-demand in Bangladesh using the AsiaFish model, with special emphasis on the role of fish in macronutrient and micronutrient supply to address the nation's malnutrition and nutrition security challenges. A business-as-usual (BAU) scenario followed historical trends for exogenous variables used in the model. The four alternative scenarios explored: the implications of increase productivity of farmed tilapia, pangasius and rohu carp (AS1); improvements in the quality of feeds (AS2); disease outbreak in farmed shrimps and prawns (AS3); and climate change impacts (AS4). The BAU scenario indicates that aquaculture growth will be a prominent contribution to increasing total fish supply and demand and fish exports to 2040. Apart from the scenarios that are favourable to aquaculture sector development, other alternative scenarios highlighted the lower growth rate of capture fisheries and aquaculture compared to BAU, resulting in declining in per capita fish consumption, fish exports and nutrient supply from fish as a consequence. Increased availability of aquaculture fish can slightly compensate for the lower growth of capture fisheries in term of their nutrition quality and di-etary diversity, particularly for poor consumers. Policies towards sustaining fisheries and a nutrition-sensitive approach to aquaculture is recommended as both capture fisheries and aquaculture are essential for sustain-ing healthy and nutritious diets in Bangladesh.

Species and farmed types of tilapia have become one of the world's most popular aquaculture products and provide nutrition and livelihood to rural and urban communities around the world.* This popularity has been due to technological advances in fish health, farming systems, breeding and genetics, engineering, marketing as well as wide consumer acceptance and the special biological characteristics of tilapia that enable them to survive and grow in a variety of environments and farming systems. As the farming of tilapia has become more widespread, so have the concerns around fish health and disease prevention and cure. To review the status of tilapia health, disease prevention and cure, the Food and Agriculture Organization of the United Nations (FAO) and INFOFISH convened a virtual International Technical Seminar, Tilapia health: quo vadis,† that brought together 1700 participants from over 100 countries. A call for expression of interest was released after the event, to develop the presentations into full articles for publication as a Special Issue at Reviews in Aquaculture. Eight groups of authors responded to the call and the eight papers now constitute this Special Issue. The FAO Lead Technical Officer (Melba G. Bondad-Reantaso), guest editors (J.R. Arthur, Devin M. Bartley, Kevin Fitzsimmons, and Michael J. Phillips), authors and entities that funded the papers as Open Access (indicated in individual papers) are gratefully acknowledged. The virtual event was supported by two FAO projects, namely: GCP/RAF/510/MUL Enhancing capacity/risk reduction of emerging Tilapia Lake Virus (TiLV) to African tilapia aquaculture and TCP/INT/3707 Strengthening biosecurity (policy and farm-level) governance to deal with Tilapia lake virus. The special issue builds on the recent review of tilapia published as a special virtual issue in RAQ 15:1 (2023); with articles that focus on fish health issues along with other articles that set the scene for tilapia farming globally. The paper by El-Sayed and Fitzsimmons, From Africa to the World- the Journey of Nile tilapia, documents how Nile tilapia, first farmed by ancient Egyptians 4000 years ago, has been moved from Africa to farming systems around the world to become one of the most important farmed species. The review further reveals that although Nile tilapia often supports inland capture fisheries as well as aquaculture production, tilapia introductions have in some cases adversely impacted local cichlid species, and reduced abundance of other fishery resources. Farmed tilapia producers and processors have been leading the seafood industry in several aspects of processing, value adding, and packaging. The dependable supply and pricing of farmed tilapia and its value in several sectors, for example, food service, fast casual dining, frozen meals, as well as fresh seafood counters, have allowed processors and marketers to invest in novel value-added processing and packaging. This has only been possible because the tilapia industry has invested in advanced production systems and fish health. Much of the tilapia sold in international trade is processed in the producing country. Often fillets are marketed leaving about 70 percent of the fish unused. The paper, How value addition by utilization of tilapia processing by-products can improve human nutrition and livelihood, by Peñarubia and co-authors, reveals a wide range of other products that are or could be utilized in the supply chain. So-called ‘by-products’ of processed tilapia that may be discarded or used for animal feed, can provide additional income to workers in the tilapia supply chain. In addition to nutritious products such as fish cakes and sausage, tilapia skins are processed to produce leather and gelatin, heads and bones can be turned into flour or supplements, and collagen from fish scales and bones have potential in the cosmetic and pharmaceutical fields. The authors point out that further research and development, along with marketing are needed to fully utilize the wide range of products available from tilapia. The paper by Zimmerman and co-authors, The future of intensive tilapia production and the circular bioeconomy without effluents: biofloc technology, recirculation aquaculture systems, Bio-RAS, partitioned aquaculture systems, and integrated multitrophic aquaculture, describes several of the most innovative fish farming systems allowing farmers to grow more fish in smaller areas with fewer inputs. Recirculating systems, aquaponics, bioflocs, in-pond raceways are just some of the more advanced, or intensive, aquaculture methods that were mostly pioneered using tilapia and are now being tested with other species. The paper provides a nice overview of these systems and their particular pro's and con's. In, Strategies to enhance tilapia immunity to improve their health in aquaculture, Wang and co-authors provide an overview of the benefits of enhancing the immune response to improve tilapia health, in turn reducing the levels of pathogens within tilapia farming systems. The authors review the immune system of tilapia and the importance of the gut microbiome. They then summarize the strategies used to reduce the impact of disease in tilapia culture through enhancement of the immune system, including the feeding of probiotic and prebiotic supplements to modulate the gut microbiota, the use of herbal medicines and immunostimulants to enhance immunity to disease, and the existing and potential use of vaccines to prevent infections. They note that emerging and re-emerging diseases such as streptococcosis, tilapia lake virus disease, and infectious spleen and kidney necrosis virus disease have resulted in high levels of morbidity and mortality, production losses and trade restrictions. In the absence of effective husbandry management, disease prevention strategies and appropriate biosecurity measures, these and other infectious diseases will continue to challenge the sustainability of global tilapia aquaculture. They then look at the economics of applying immune enhancement strategies in tilapia culture, noting that the decision to use these products depends on multiple factors including farming practice, farmer perception, and the overall cost-benefits. They note that effective husbandry management through maintaining high water quality, adequate nutrition, and good biosecurity will create a less stressful environment for fish. Rapid response to epidemic events and the availability of rapid and accurate diagnostic methods are important to limit the damage caused by disease. Vaccination as a means of controlling infectious diseases is one of the most significant and successful health practices within the aquaculture industry. The review, Improving tilapia biosecurity through a value chain approach, by MacKinnon and co-authors explores the value chain perspective to assess and manage risks of disease threats and losses in tilapia aquaculture. The paper outlines the tilapia value chain as a starting point, then assesses the important infectious agents of tilapia that may affect different parts in the value chain. The paper then describes how risk analysis can be applied to identify critical control points in the value chain and potential risk mitigation measures that may be implemented at those points. It emphasizes, as many of the other papers illustrate, that the control of diseases of tilapia requires a multi-faceted approach across the whole ‘aquaculture system’, with control measures chosen based on their feasibility, effectiveness and sustainability. In, A global review of problematic and pathogenic parasites of farmed tilapia, Shinn and co-authors provide an extensive and detailed global accounting of the protistan and metazoan parasites of tilapias, with emphasis on those species having demonstrated or potential impact to tilapia aquaculture. The authors summarize more than 2500 host–parasite records from 73 countries and more that 820 recorded tilapia introductions. For each major parasite taxonomic group, they highlight those parasites that have been translocated along with their tilapine hosts or have been acquired from the new environments into which tilapia have been introduced, together with remarks on their taxonomy, reported geographic distribution (including translocations), pathology, status, and future directions of research, and approaches to treatment and control. They note that while Africa has enormous potential for aquaculture development, substantial knowledge gaps about tilapia parasites remain for many African states, which creates associated production and biosecurity risks. Globally, tilapias host a rich fauna of parasites, with new species still being encountered. This review and its associated supplementary tables will be of high value to fish parasitologists in general, to diagnosticians, to tilapia farmers encountering parasite problems in their facilities, and to government scientists conducting import risk analyses for proposals to introduce tilapias to new geographic areas. Tilapia has often been described as extremely hardy fish with very few disease problems. While this is generally true, rearing more and more fish intensively can induce stressful conditions that allow pathogens to take hold and allow a disease to spread. Likewise, fish selected for fast growth, colour morphs and/or body conformation may have allowed some of the innate hardiness to have been degraded. The paper by Haenen and co-authors, Bacterial diseases of tilapia, their zoonotic potential and risk of antimicrobial resistance provides a thorough overview of bacterial diseases and some associated pathologies that have and are affecting commercial farms rearing tilapia. While the losses endured by the tilapia industry have been less than salmon or shrimp farming, no farmer wants to lose fish and see income decline. Treatments and vaccines are described for the various bacteria which have been associated with significant mortalities. In their review, From the basics to emerging diagnostic technologies: What is on the horizon for tilapia disease diagnostics?, Ha Dong and co-authors stress that the intensification of tilapia farming has exacerbated losses due infectious diseases and that the disease diagnostics play a crucial role in aquaculture biosecurity and health management. However, the recent proliferation of cutting-edge molecular methods in aquaculture has shifted the focus of researchers and users away from basic approaches and towards molecular diagnostics, despite the fact that many diseases can be rapidly diagnosed using inexpensive, simple microscopic examination. This review highlights the importance of the three levels of diagnostics for diseases of tilapia to promote the integration of both basic and advanced methods to achieve accurate and meaningful diagnostic results. The authors thus emphasize the need for frequently overlooked but basic procedures such as case history records, gross pathology, presumptive diagnostic methods, and histopathology. They also provide an in-depth review of current and emerging molecular diagnostic technologies for tilapia pathogens, including polymerase chain reaction methods, isothermal amplification methods, CRISPR-based detection, and lateral flow immunoassays. They also discuss the future of tilapia disease diagnostics, including next generation sequencing, artificial intelligence, environmental DNA/RNA and point-of-care testing, and a future vision for transferring these technologies to farmers and stakeholders for a sustainable aquatic food system transformation. Undoubtedly, tilapia, and especially Nile tilapia, will continue to be one of the most important groups of farmed aquatic species. The material reviewed in this special edition provides valuable information to resource managers, fish farmers, processors, marketers, and vendors to help ensure that tilapia aquaculture develops responsibly and provides beneficial outcomes to communities and the environment. Devin M. Bartley: Conceptualization; project administration; writing – original draft; writing – review and editing. J. Richard Arthur: Conceptualization; writing – original draft; writing – review and editing. Kevin Fitzsimmons: Conceptualization; writing – original draft; writing – review and editing. Michael J. Phillips: Conceptualization; writing – original draft; writing – review and editing. Melba G. Bondad-Reantaso: Conceptualization; writing – original draft; writing – review and editing. Data sharing not applicable to this article as no datasets were generated or analysed during the current study.

Blue foods, sourced in aquatic environments, are important for the economies, livelihoods, nutritional security and cultures of people in many nations. They are often nutrient rich1, generate lower emissions and impacts on land and water than many terrestrial meats2, and contribute to the health3, wellbeing and livelihoods of many rural communities4. The Blue Food Assessment recently evaluated nutritional, environmental, economic and justice dimensions of blue foods globally. Here we integrate these findings and translate them into four policy objectives to help realize the contributions that blue foods can make to national food systems around the world: ensuring supplies of critical nutrients, providing healthy alternatives to terrestrial meat, reducing dietary environmental footprints and safeguarding blue food contributions to nutrition, just economies and livelihoods under a changing climate. To account for how context-specific environmental, socio-economic and cultural aspects affect this contribution, we assess the relevance of each policy objective for individual countries, and examine associated co-benefits and trade-offs at national and international scales. We find that in many African and South American nations, facilitating consumption of culturally relevant blue food, especially among nutritionally vulnerable population segments, could address vitamin B12 and omega-3 deficiencies. Meanwhile, in many global North nations, cardiovascular disease rates and large greenhouse gas footprints from ruminant meat intake could be lowered through moderate consumption of seafood with low environmental impact. The analytical framework we provide also identifies countries with high future risk, for whom climate adaptation of blue food systems will be particularly important. Overall the framework helps decision makers to assess the blue food policy objectives most relevant to their geographies, and to compare and contrast the benefits and trade-offs associated with pursuing these objectives.

Chemical and pathogenic hazards in aquaculture supply chains threaten the provision of safe aquatic food. The Seafood Risk Tool is an integrated, semi-quantitative system that develops bespoke supply chain and risk management strategies.

Small-scale fisheries account for 90% of global fishers and 40% of the global catch. Effectively managing small-scale fisheries is, therefore, crucial to progressing the United Nations Sustainable Development Goals (SDGs). Co-management and community-based fisheries management are widely considered the most appropriate forms of governance for many small-scale fisheries. We outlined relationships between small-scale fisheries co-management and attainment of the SDGs, including evidence for impacts and gaps in dominant logic. We identified 11 targets across five SDGs to which small-scale fisheries co-management (including community-based fisheries management) can contribute; the theory of change by which these contributions could be achieved; and the strength of evidence for progress toward SDG targets related to various co-management strategies. Our theory of change links the 11 SDG targets by qualifying that progress toward some targets is contingent on others being achieved first. We then reviewed 58 case studies of co-management impacts from the Pacific Islands--a region rich in local marine governance--to evaluate evidence of where, to what degree, and with how much certainty different co-management strategies conferred positive impacts to each SDG target. These strategies included access restrictions, permanent area closures, periodic closures, and gear and species restrictions. Although many studies provide evidence linking multiple co-management strategies to improvements in resource status (SDG 14.4), there was limited evidence of follow-on effects, such as improvements in catch (SDG 2.3, 2.4), livelihoods (SDG 1.2), consumption (SDG 2.1), and nutrition (SDG 2.2). Our findings suggest that leaps of logic and assumptions are prevalent in co-management planning and evaluation. Hence, when evaluating co-management impacts against the SDGs, consideration of ultimate goals is required, otherwise, there is a risk of shortfalls between aspirations and impact.

Aquatic foods, or “seafood”, are an integral part of the global food system that contribute significantly to many dimensions of human wellbeing, including livelihoods and food and nutrition security. Fish, molluscs, crustaceans, algae and other aquatic foods are of particular importance in low- and middle-income countries as a source of employment, income, and nutrition for many poor and vulnerable people, including women. Global concern over the ability of fisheries and aquaculture to sustainably meet future seafood demand is driving improvements in technology and management. It has also inspired the emergence of plant-based and cell-based seafood, collectively termed “alternative seafood”. Growing investment, consumer demand, and participation by major food companies in the alternative seafood sector necessitate an evaluation of potential opportunities and challenges alternative seafood poses to food systems. This paper explores key economic, social, and environmental implications associated with production, distribution, and consumption of alternative seafood and its interactions with fisheries and aquaculture over the next decade, with specific emphasis on low- and middle-income countries. Available data on current supply and projected growth suggest that alternative seafood may account for almost eight percent of global seafood supplies destined for human consumption in 2030. Assuming current production techniques and expected technological development, the sector has potential for reduced environmental impacts relative to the existing fisheries and aquaculture sectors. However, its potential to impact livelihoods, food and nutrition security, and the environment remains largely a matter of conjecture due to the lack of robust data. Mechanistically, it is believed that growth of alternative seafood supplies will lessen demand for “conventional” seafood and/or meat, a scenario with implications for livelihoods, food and nutrition security, and the environment. Such changes are contingent on technological development, human and institutional behavior, market forces, and ecological linkages and as such, remain speculative. Nevertheless, as a novel sector, new food, and potential alternative to conventional seafood and/or meat, society has an opportunity to shape the growth of alternative seafood and its contribution to national and global development goals. This paper identifies knowledge gaps that require further research to inform inclusive, equitable, and sustainable development and governance of the emerging alternative seafood sector.

Blue foods play a central role in food and nutrition security for billions of people and are a cornerstone of the livelihoods, economies, and cultures of many coastal and riparian communities. Blue foods are extraordinarily diverse, are often rich in essential micronutrients and fatty acids, and can often be produced in ways that are more environmentally sustainable than terrestrial animal-source foods. Capture fisheries constitute the largest wild-food resource for human extraction that would be challenging to replace. Yet, despite their unique value, blue foods have often been left out of food system analyses, policies, and investments. Here, we focus on three imperatives for realizing the potential of blue foods: (1) Bring blue foods into the heart of food system decision-making; (2) Protect and develop the potential of blue foods to help end malnutrition; and (3) Support the central role of small-scale actors in fisheries and aquaculture. Recognition of the importance of blue foods for food and nutrition security constitutes a critical justification to preserve the integrity and diversity of aquatic species and ecosystems.

Food system is a powerful concept for understanding and responding to nutrition and sustainability challenges. Food systems integrate social, economic, environmental and health aspects of food production through to consumption. Aquatic foods are an essential part of food systems providing an accessible source of nutrition for millions of people. Yet, it is unclear to what degree research across diverse disciplines concerning aquatic foods has engaged food systems, and the value this concept has added. We conducted a systematic review of fisheries, aquaculture and aquatic food literature (2017–2019) to determine the following: the characteristics of this research; the food systems components and interrelations with which research engaged; and the insights generated on nutrition, justice, sustainability and climate change. Sixty five of the 88 reviewed articles focussed on production and supply chains, with 23 considering human nutrition. Only 13% of studies examined low- and middle-income countries that are most vulnerable to undernutrition. One third of articles looked beyond finfish to other aquatic foods, which illuminated values of local knowledge systems and diverse foods for nutrition. When aggregated, reviewed articles examined the full range of food system drivers—biophysical and environmental (34%), demographic (24%) and socio-cultural (27%)—but rarely examined interactions between drivers. Future research that examines a diversity of species in diets, system-wide flows of nutrients, trade-offs amongst objectives, and the nutritional needs of vulnerable social groups would be nudging closer to the ambitions of the food systems concept, which is necessary to address the global challenges of equity, nutrition and sustainability.

Aquatic foods are increasingly being recognized as having an important role to play in an environmentally sustainable and nutritionally sufficient food system. Proposals for increasing aquatic food production often center around species, environments, and ambitious hi-tech solutions that mainly will benefit the 16% of the global population living in high-income countries. Meanwhile, most aquaculture species and systems suffer from large performance gaps, meaning that targeted interventions and investments could significantly boost aquatic food supply and access to nutritious foods without a concomitant increase in environmental footprints. Here we contend that the dialogue around aquatic foods should pay greater attention to identifying and implementing interventions to improve the productivity and environmental performance of low-value commodity species that have been relatively overlooked in this regard to date. We detail a range of available technical and institutional intervention options and evaluate their potential for increasing the output and environmental performance of global aquaculture.

The COVID-19 pandemic is a systemic shock that affects all areas of the global food system. A growing range of impacts on aquatic food producers, value chain actors and consumers is evident. In response, the report provides the impacts of COVID-19 on aquatic food value chains in Bangladesh, Egypt, India, Myanmar and Nigeria. Results show that: (1) COVID-19 and associated containment measures severely disrupted aquatic food value chains, but effects on supply were relatively short-lived;(2)Demand for aquatic foods has yet to recover to pre-pandemic levels;(3) prices of aquatic foods have downward trend while prices of manufactured feeds have risen;and (4) COVID-19 has exacerbated pre-existing inequalities. As COVID-19 pandemic reversed years of progress on key human development indicators, it is important to revitalize aquatic food value chains to protect livelihoods and human nutrition. The paper also provides policy recommendations for both supply and demand sides.

Aquatic foods from marine and freshwater systems are critical to the nutrition, health, livelihoods, economies and cultures of billions of people worldwide, but climate-related hazards may compromise their ability to provide these benefits. Here, we estimate national-level aquatic food system climate risk using an integrative food systems approach that connects climate hazards impacting marine and freshwater capture fisheries and aquaculture to their contributions to sustainable food system outcomes. We show that without mitigation, climate hazards pose high risks to nutritional, social, economic and environmental outcomes worldwide—especially for wild-capture fisheries in Africa, South and Southeast Asia, and Small Island Developing States. For countries projected to experience compound climate risks, reducing societal vulnerabilities can lower climate risk by margins similar to meeting Paris Agreement mitigation targets. System-level interventions addressing dimensions such as governance, gender equity and poverty are needed to enhance aquatic and terrestrial food system resilience and provide investments with large co-benefits towards meeting the Sustainable Development Goals.

The COVID-19 pandemic is a shock affecting all areas of the global food system. We tracked the impacts of COVID-19 and associated policy responses on the availability and price of aquatic foods and production inputs during 2020, using a high frequency longitudinal survey of 768 respondents in Bangladesh, Egypt, India, Myanmar, Nigeria. We found the following: (1) Aquatic food value chains were severely disrupted but most effects on the availability and accessibility of aquatic foods and production inputs were short-lived. (2) Impacts on demand for aquatic foods, production inputs, and labor have been longer lasting than impacts on their supply. (3) Retail prices of aquatic foods spiked briefly during March-May 2020 but trended down thereafter, whereas prices of production inputs rose. These trends suggest a deepening ‘squeeze’ on the financial viability of producers and other value chain actors. (4) Survey respondents adapted to the challenges of COVID-19 by reducing production costs, sourcing alternative inputs, diversifying business activities, leveraging social capital, borrowing, seeking alternative employment, and reducing food consumption. Many of these coping strategies are likely to undermine well-being and longer-term resilience, but we also find some evidence of proactive strategies with potential to strengthen business performance. Global production of aquatic food likely contracted significantly in 2020. The importance of aquatic food value chains in supporting livelihoods and food and nutrition security in Asia and Africa makes their revitalization essential in the context of COVID-19 recovery efforts. We outline immediate and longer-term policies and interventions to support this goal.

Climate information services (CIS) are increasingly in demand to assist farmers in managing risks associated with climate variability and extremes experienced in food production. However, there are significant gaps in the availability and accessibility of these services, especially in aquatic food production in developing countries. In response, this study aims to generate the background knowledge for developing climate information and decision support services tailored for aquaculture farmers in Bangladesh. We surveyed 800 fish-farming households, interviewed 30 key informants, and conducted a systematic literature review to identify climate-sensitive operations and management decisions in aquaculture and to document fish-farmers' awareness of the relationships between climate variability and aquatic food production systems. We also sought to identify the lead time and communication method(s) needed to deploy forecasts effectively and prepare aquaculture farmers to act in response to the forecasts. A fish-farming activity calendar was developed that identified high temperature, cold spell, heavy rainfall, and dry spell events as key climatic phenomena affecting year-round aquaculture operations, including pond preparation and maintenance, fingerling stocking, grow-out management, and harvesting. We also identified five climate-sensitive management decision points and 26 potential advisories in line with specific climate variability to manage induced risks in the day-to-day operations of fish farmers. Finally, the research team developed a decision framework based on the temperature and rainfall thresholds for the grow-out phase of four widely cultivated and economically important fish species in Bangladesh. This innovative decision support approach is to our knowledge the very first endeavor to develop CIS using species-specific temperature and rainfall thresholds to reduce climate risks and ensure resilience capacity for South Asian aquaculture system.

Hilsa shad is the largest single fish species, contributing 12% of the total fish production in Bangladesh. Since the rapid decline of its harvest in early 2000, the government of Bangladesh took various initiatives to accelerate the hilsa production and introduced the hilsa fisheries management action plan in 2005. Under WorldFish led enhanced coastal fisheries project, implemented in partnership with the Department of Fisheries, the hilsa fishery reversed and experienced record harvest in 2016. Therefore, this study was undertaken to explore the contributions and benefits of this increased hilsa shad production among value chain actors. The results revealed that increased catches have significant impacts on the volumes of hilsa that were handled by the value chain actors, which depressed market price along the value chain. However, the increased amounts of hilsa harvested compensated for the reduced price and led to increased profits, increased household incomes of the value chain actors, and enhanced fish consumption at the household levels. The increased hilsa catch also had positive and significant impacts on credit repayment. Therefore, the incentive-based co-management system deserves continuation to improve the livelihood of the poor hilsa fishers, to increase the income of the value chain actors and to ensure a sustainable hilsa fishery for Bangladesh.

Migration of an anadromous fish to heterogeneous environment continuously enforces a selective pressure that incorporates a wide range of life-history strategies by which individuals adapt to the prevailing conditions. Therefore, we used the landmark-based morphometric truss network method and nextRAD genotyping-based putatively adaptive SNP loci dataset to know how the anadromous Hilsa shad (Tenualosa ilisha) morpho-genetically adapt to the heterogeneous habitats across their migratory routes by investigating 300 individuals, collected from nine strategic sampling sites covering sea, estuary, and upstream freshwater rivers. Different multivariate and clustering analyses revealed that the riverine populations were morphometrically wider (broad type) than the estuarine and marine populations (slender type). In the case of riverine population, the north-western turbid population (the Padma and Jamuna rivers) had wider body depth than the north-eastern clear water population (the Meghna river). The linear model and spatial multivariate analyses further revealed that the outcomes of morphometric dataset were in complete concordance with the results of putatively adaptive SNP loci dataset for different Hilsa shad populations. The gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways enrichment analysis of the 36 genes, which are encoded by the putative adaptive SNP loci, supported the presence of multiple genes involved in the growth, metabolism, homeostasis and osmoregulation related functions. Several non-mutually exclusive hypotheses were attributed to explain the observation of continuum differentiation at both phenotypes and genotypes: (i) the genetic variation largely determines the morphometric discrimination, (ii) the interactive evolutionary processes and salinity predominantly contribute to the morphogenetic difference between the marine-estuarine and the freshwater riverine populations, (iii) environmental heterogeneity largely influences the genotypes leading to the phenotypic plasticity, and (iv) the local environmental heterogeneity may contribute to the morphogenetic divergence between the riverine populations. Finally, we concluded that the genetic adaptation, phenotypic plasticity and interactive ecological and evolutionary consequences jointly determine the morphogenetic divergence of Hilsa shad. The interaction of all of these forces and their relative strength in heterogeneous environments, however, made it rather challenging to determine the most probable selective pressure, which has shaped the Hilsa shad morphogenetic divergence across their diverse migratory habitats.

Egypt faces multiple interlinked challenges such as unemployment, poverty and gender inequality that pose tremendous barriers in the current efforts to achieve sustainable development. Aquaculture is a primary sector of the economy that has high potential to not only for provide nutritious food, but also to contribute to the national economy. The aquaculture value chain provides substantial employment generation opportunities, including for females and the youth. This paper assesses employment generation along the different stages of the aquaculture value chain in the main governorates that are responsible for about 80% of the Egyptian aquaculture production. In particular it analyses data from surveys in hatcheries (N = 40), feed mills (N = 14), fish farms (N = 234), and fish trading and retailing (N = 182) as a proxy of employment generation patterns for the entire sector. We estimated that aquaculture generates 19.56 Full Time Equivalent (FTE) jobs per 100t of produced fish along the entire value chain. However most of these jobs are generated for males over 30 years of age, with few jobs for females or younger people. Most jobs for female are currently generated at the retailing stage. Boosting employment generation across the entire value chain, especially for females and the youth, can contribute to the attainment of multiple Sustainable Development Goals (SDGs) such as SDG 8 and SDG 5.

For aquaculture to continue along its current growth trajectory and contribute towards achieving the Sustainable Development Goals, value chains must become more inclusive. Smallholders and other local value chain actors are often constrained by circumstances and market failures in the global aquaculture industry. Integrating these actors into aquaculture value chains through inclusive business models (IBMs) is often touted as a solution to sustainable and ethical trade and business that can generate development outcomes. We reviewed 36 papers under seven business models commonly used in agriculture development to assess their application in aquaculture value chains in lower-income countries. A global value chain (GVC) analysis is used to unpack the economic and social upgrading objectives of the different IBMs, as well as the types of relational coordination used between actors in the chain to achieve development outcomes. The extent to which these IBMs helped poor actors overcome certain barriers is evaluated with a focus on how they may ensure or be a risk to inclusiveness through the relations and upgrading opportunities evident in their make-up. The analysis found that the majority of the models focused on economic upgrading over social upgrading. Providing opportunities for the latter is key to achieving the inclusive objectives of IBMs. Greater horizontal coordination between actors can create further opportunities for economic upgrading established under vertical coordination with other nodes upstream and downstream in a value chain. There is a need to further contextualize these models to aquaculture systems and develop clear indicators of inclusiveness.