Maria Jose Darias

Micronutrient deficiencies are prevalent in Madagascar, where diets rely heavily on starchy staples and access to animal-source foods is limited. Small dried fish (SDF) are widely available, yet their nutritional value and health risks remain poorly documented. We combined market surveys, taxonomic identification, and micronutrient and heavy metal analyses of nine SDF types collected along National Road 7. The samples encompassed 33 fish families, were dominated by small pelagic species (Clupeidae and Engraulidae), and were appreciated by consumers. A daily portion (5 g for infants; 10 g for young children and women of childbearing age) contributed substantially to Recommended Nutrient Intakes (RNIs). Across samples and groups, SDF were rich (>30% of RNI) in selenium and, for infants and young children, in calcium. All samples were a source of (>15% of RNI), or rich in, phosphorus, whereas iron contributions were more variable but often substantial. Several samples exceeded 100% of RNIs for selenium, calcium, iron, or manganese in infants and young children, and some were also sources of magnesium and, less frequently, zinc. Vitamin A was absent from sun-dried samples but detected in a smoked freshwater type. Heavy metal concentrations varied markedly, and portions of several types led to estimated exposures to inorganic arsenic or cadmium exceeding reference values, whereas freshwater species and some pelagic types showed a more favorable nutrition-risk balance. Overall, SDF are affordable, nutrient-dense foods with strong potential to alleviate micronutrient deficiencies in Madagascar, while highlighting the need for type-specific guidance to balance nutritional benefits and contamination risks.

1. Temperature is a key environmental determinant of fish physiology, influencing distribution patterns, life-history traits, and core biological functions such as metabolism, growth, reproduction,...

Paiche (Arapaima sp.) is an emblematic species of the Peruvian Amazon, yet sustainable production remains constrained by the limited availability of fry in captivity. This study aimed to evaluate the partial replacement of Artemia sp. by Moina sp. during the live-feeding phase and the effect of early weaning onto a commercial trout diet on growth, survival, and digestive system histology. The 37-day feeding trial was conducted with six treatments in triplicate, defined by three weaning sizes (3, 3.5, and 4 cm total length) and two live-feed regimes (100% Artemia sp. or 50% Artemia sp. + 50% Moina sp.). All groups were weaned onto the same commercial diet. Results showed that replacing 50% of Artemia sp. with Moina sp. did not compromise initial performance. However, fry assigned to weaning at 4 cm showed reduced growth while remaining exclusively on live feed, suggesting limitations of the live-feeding protocol at that size. Weaning at 4 cm was associated with better growth and survival indicators than weaning at 3 and 3.5 cm. Nonetheless, the commercial trout diet was unsuitable for early weaning, as evidenced at the histological level by alterations such as lumen obstruction, villi deterioration, and intestinal epithelial hyperplasia. Overall, these results highlight the need to develop paiche-specific starter diets tailored to the requirements of early life stages.

Arapaima spp., the world’s largest scaled freshwater fish, native to the Amazon and Essequibo river basins, are valued in aquaculture for their rapid growth and ornamental appeal. However, reliance on natural breeding and parental care in earthen ponds results in variable fingerling survival, hindering production. This study investigated the morphology and functionality of the digestive system of Arapaima sp. fingerlings from the Peruvian Amazon and evaluated the feasibility of early weaning onto compound diets to optimise growth and survival. Fingerlings were collected from a pond at 3.19 ± 0.03 cm total length (TL) and reared in a recirculating aquaculture system at 29 ºC under a 12L:12D photoperiod. Fish were successfully weaned from Artemia spp. nauplii onto an experimental compound diet (60% protein, 15% lipid) from 3.26 ± 0.02 cm TL within three days. Histological and gene expression analyses of key digestive enzyme precursors and appetite-regulating peptides (α-amylase, phospholipase A2, lipoprotein lipase, trypsinogen, chymotrypsinogen, pepsinogen, and peptide YY) revealed a mature digestive system, with enhanced digestive efficiency observed at 5.05 ± 0.34 cm TL. Based on digestive enzyme expression profiles and gut morphology, early juvenile Arapaima sp. possess a digestive physiology consistent with that of an omnivorous species with a preference for animal prey. The middle intestine was identified as a key site for fatty acid absorption and feed intake regulation. This study presents a novel, comprehensive analysis of digestive enzyme gene expression and associated tissue morphology in the genus Arapaima. It provides new insights into their digestive physiology and establishes the feasibility of early weaning onto formulated diets. Future research should explore the interplay between optimised compound feed formulations and refined early rearing protocols to maximise growth and survival throughout development.

Over the past three decades, global capture fisheries production has remained relatively unchanged, while aquaculture production has strongly increased to satisfy the demands of a growing world population. Since 2022, aquaculture production has surpassed that of capture fisheries. Although the environmental performance of aquaculture has shown positive trends over the last 20 years, further research is necessary to address its sustainability challenges, such as reducing the use of marine resources in aquafeeds, limiting habitat degradation, and improving disease management.Research in aquaculture has traditionally focused on enhancing the growth and health of farmed species, rather than addressing human nutrition concerns. Nutrition-sensitive aquaculture proposes a new paradigm that moves beyond merely producing aquatic foods to fostering well-being. This involves promoting diversification and sustainable intensification of aquaculture production, investigating a wider range of aquatic species and their dietary contributions to prioritize nutrient-rich alternatives that improve dietary diversity, and encouraging nutrition-enhancing aquaculture feeding practices, among other strategies.Based in South Africa, the International Joint Laboratory LIMAQUA—lima means ‘to cultivate’ in Xhosa, a language spoken in Southern Africa—conducts an interdisciplinary research and training programme to tackle nutritional and sustainability challenges of marine aquaculture, contributing to food and nutrition security, poverty alleviation, and income creation in the region. LIMAQUA brings together a team of scientists specializing in biology, biotechnology, socioeconomics, food science and human nutrition. The research and training activities are grounded in the sustainability science approach—an inter- and transdisciplinary approach co-constructed with academic, governmental, private sector, and civil society actors. Specifically, LIMAQUA focuses on i) developing sustainable marine aquaculture practices for target species, including research on culture technologies, sustainable nutrition, welfare and health of farmed organisms (One Health approach), and aquaculture-environment interactions; ii) adopting an integrated approach to marine aquaculture development; iii) creating aquaculture-based food and nutritional products; iv) providing capacity-building and training; and v) fostering collaborations within Africa.This presentation will examine examples of research activities undertaken within the framework of LIMAQUA. This includes the development of integrated multitrophic aquaculture systems, assessments of social acceptability of aquaculture development, and evaluations of the nutrient supply from local aquaculture production, highlighting sustainable and nutrition-sensitive approaches in marine aquaculture.

Aquatic foods—including fish, invertebrates, algae, and aquatic plants—play a crucial role in global food and nutrition security. They provide 15% of global animal proteins and are particularly crucial in many low-income countries. In addition to protein, aquatic foods are rich sources of essential fatty acids, vitamins, and minerals. Despite their importance, these foods are often underrepresented in policy dialogues and funding priorities. Many nations manage aquatic food production predominantly from an economic standpoint, focusing on exports rather than domestic nutritional needs. To shift this paradigm, promoting nutrition-sensitive aquatic food systems is imperative. This involves shifting from viewing fisheries and aquaculture only as a means for producing aquatic foods to a means for promoting overall well-being, requiring the integration of socio-economic, environmental, and cultural dimensions.Over the last thirty years, aquaculture has grown rapidly to meet the increasing global demand of aquatic foods. While per capita consumption of aquatic foods is projected to rise by 2030 globally, Africa is an exception due to population growth outpacing supply. Although African aquaculture production has expanded significantly in recent years, it represents less than 2% of the global aquaculture production, with marine aquaculture production being one of the lowest worldwide.The AfriMAQUA initiative was established in 2019 as a collaborative network of researchers from various African countries and France, aimed at enhancing the sustainability of marine aquaculture in Africa. In 2023, it was endorsed as a programme of the UN Decade of Ocean Science for Sustainable Development 2021-2030. AfriMAQUA seeks to promote South-South-North collaborations and knowledge sharing across Africa, emphasizing coordinated efforts to develop sustainable and nutrition-sensitive marine aquaculture. The programme focuses on 1) fostering collaborative research, 2) enhancing skills and knowledge through training and capacity-building, and 3) employing participatory approaches to identify drivers and barriers to the sustainable development of marine aquaculture.This presentation will examine case studies of collaborative research projects undertaken by AfriMAQUA partner countries. These studies highlight practical applications of sustainable approaches in marine aquaculture adapted to local contexts and demonstrate capacity-building efforts. By sharing these examples, we aim to illustrate the tangible impacts of coordinated research activities on the sustainability and nutritional outcomes of marine aquaculture in Africa.

Madagascar is renowned for its wide range of aquatic organisms, particularly crabs, octopus and fish. The latter are particularly abundant and are sold in a variety of forms (fresh, salted, smoked or dried) and sizes, ranging from large to small individuals. Small dried fish (SDF) are abundant and omnipresent across Malagasy markets. However, they remain poorly understood in terms of their cultural and taxonomic diversity, as well as their nutritional benefits. As an accessible and affordable food source, SDF could help alleviate micronutrient deficiencies, a major issue in Madagascar. In this study, we explored the diversity and nutritional importance of SDF sampled at 16 markets and 12 towns along the National Road 7, which connects Toliara (coast) to Antananarivo (inland). For that purpose, we combined: (i) a socio-economic survey of 112 vendors, (ii) taxonomic (traditional and molecular) analyses to identify the diversity of fish species sold across 131 batches of SDF, and (iii) nutritional and heavy metal analyses of the 10 most popular batches. We assessed their the potential intake of key nutrients and heavy metals from SDF and contribution to Recommended Dietary Allowance (RDA) and maximum Tolerable Weekly Intake (TWI), respectively, considering daily? portions of 10 g for infants (7-11 months) and 20 g for both children (1-3 years) and women of childbearing age (15-50 years). We identified 43,819 individual fish specimens corresponding to 8.1 kg across the 131 batches sampled. These specimens were classified into 233 morpho-species belonging to 110 genera and 61 families, with the Clupeidae, Engraulidae and Poeciliidae families being the most represented in terms of both biomass and abundance. Thirty distinct types of SDF were characterized, of which 19 are commonly consumed by humans, such as the freshwater fish varieties Pirina and Varilava, with appreciation rates of 89% and 83% respectively. SDF are mainly consumed with rice, cassava or maize, and are generally prepared in sauces, fried or mixed with leafy vegetables. Consumption of SDF provides essential nutrients for humans. Across the three population groups, SDF contribute at least 30% of the RDA for selenium, calcium, phosphorus, magnesium and iron. For infants, a 10g portion could meet more than 81% of daily calcium and selenium RDA. Most SDF also provide more than 42% of the RDA for iron and 29% for manganese. For children 1-3 and women of childbearing age, a 20 g portion covers more than 100% of the RDA for calcium, selenium and iron, particularly for the Matsiroky, Kalatambo and Ambotsika types of SDF. In all groups, contributions to potassium, copper and zinc RDA were moderate. Vitamin A was not detected in the ten SDF lots, except for a small trace in Ambotsika. Some types of SDF (Matsiroky) exhibited by significant traces of arsenic, cadmium and lead, requiring moderate consumption. This study enhances our understanding of the potential role of SDF in health and nutritional security and identifies the types most likely to improve nutritional outcomes for the population.Key words: Small dried fish, micronutrients, heavy metals, Recommended Dietary Allowance (RDA), food security, Madagascar

Aquatic foods hold a unique potential to contribute to a much-needed transformation of food systems thanks to their high nutritional value, cultural significance, and relatively low environmental impact. However, realizing this potential requires a transformative approach to help overcome two grand challenges: sustainably increasing the production of nutritious aquatic foods and ensuring equitable access to these resources. This paper highlights the key recommendations from the White Paper on Challenge 3 (‘Sustainably nourish the global population’) of the United Nations Decade of Ocean Science for Sustainable Development (hereafter, the Ocean Decade), developed by a group of experts under the Vision 2030 process, on the science needed to support a ‘Blue Transformation’. A holistic, interdisciplinary science agenda is proposed, emphasizing strengthened institutional and public–private partnerships, prioritizing the inclusion of small-scale actors, women, and youth, and focusing on delivering science targeted to solve specific challenges. The Ocean Decade provides a platform to catalyse these efforts, fostering a paradigm shift towards inclusive, co-created science. Achieving these goals will enable aquatic food systems to contribute significantly to global food security and the Sustainable Development Goals by 2030.

The effects of three medicinal plants in the feeds of juvenile Nile tilapia (Oreochromis niloticus) were investigated on growth, survival, immunity, and digestive histology at various inclusion levels: (A) Guiera senegalensis at 0, 1, 2, 4, and 8%; (B) Pluchea odorata at 0, 0.5, 1, 2, and 4%; (C) Piliostigma reticulatum at 0, 1, and 2%; and (D) a mixture of the three at 0, 1, and 2%. After 28 days of feeding, fish were infected with Aeromonas hydrophila for 12 days. The results showed that, except for G. senegalensis, the inclusion of the medicinal plants, alone or combined, enhanced the immune response. The diet with 4% P. odorata significantly increased plasma lysozyme and bactericidal activities without affecting feed conversion efficiency or growth. Despite improved immunity, none of the treatments enhanced post-infection survival rates. However, fish fed the 1% mixture showed healthier livers and intestines, with reduced cell swelling and normal lipid deposits, followed by the 2% mixture and the control. These results highlight the potential benefits of incorporating P. odorata and the plant mixture into the diets of Nile tilapia juveniles for enhancing their immune response against A. hydrophila.

Food systems and their sustainability have been extensively studied in high-income countries (HICs), yet less so in low- and middle-income countries (LMICs), despite their importance for global food security. In this study, we conducted a systematic scoping review to describe the extent, range, and nature of peer-reviewed literature assessing the sustainability performance of food systems in LMICs. The review revealed a recent and heterogeneous literature. From this diversity, 3 archetypes of epistemological approaches emerged, classified by their purpose: observational, modeling, and transformative. All 3 approaches apply existing or tailored methods to specifically study food systems, and their objectives are to observe, model, or transform different parts of the food systems towards sustainability. Gaps in the literature include inconsistent definitions of food systems and frameworks and understudied drivers of food systems sustainability. Therefore, the development of a comprehensive and systematic inventory of frameworks and their sustainability is crucial to determine the most suitable interdisciplinary methodologies for specific contexts and generate actionable knowledge for food systems transformation.