Aquaculture is one of the most resource‐efficient and sustainable ways to produce animal protein. The Food and Agriculture Organization predicts that cultivated aquatic species will provide around 53% of the world's seafood supply by 2030. Further growth of intensive farmed aquatic species may be limited by a shortage of feed resources. The aquaculture sector therefore needs to intensify its search for alternative ingredients based on renewable natural resources. A significant increase in production will require an accelerated transition in technology and production systems, better use of natural available resources, development of high‐quality alternative feed resources and exploitation of available space. The present review discusses the urgent need to identify appropriate alternative ingredients for a sustainable future salmonid production. We describe and evaluate the most promising marine ingredients, including low‐trophic species (mesopelagic fish, zooplankton, polychaetes, macroalgae and crustaceans), novel microbial ingredients (bacteria, yeast and microalgae), insects (black soldier fly, yellow meal worm and crickets), animal by‐products (poultry meal, meat and bone meal, blood meal and hydrolysed feather meal) and by‐products from other commercial productions (trimmings and blood). Furthermore, we discuss the available volumes and need for new processing technologies and refining methods to ensure commercial production of nutritionally healthy ingredients. The essential production steps and considerations for future development of sustainable and safe seafood production are also discussed.

Cell wall disrupted and dried Microchloropsis gaditana (Mg), Tetraselmis chui (Tc) and Chlorella vulgaris (Cv) microalgae biomasses, with or without ethanol pre-treatment, were added to wheat bread at a wheat flour substitution level of 12%, to enrich bread protein by 30%. Baking performance, protein quality and basic sensory properties were assessed. Compared to wheat, Mg, Tc and Cv contain higher amounts of essential amino acids and their incorporation markedly improved protein quality in the bread (DIAAS 57–66 vs. 46%). The incorporation of microalgae reduced dough strength and bread volume and increased crumb firmness. This was most pronounced for Cv and Tc but could be improved by ethanol treatment. Mg gave adequate dough strength, bread volume and crumb structure without ethanol treatment. To obtain bread of acceptable smell, appearance, and colour, ethanol treatment was necessary also for Mg as it markedly reduced the unpleasant smell and intense colour of all algae breads. Ethanol treatment reduced the relative content of lysine, but no other essential amino acids. However, it also had a negative impact on in vitro protein digestibility. Our results show that Mg had the largest potential for protein fortification of bread, but further work is needed to optimize pre-processing and assess consumer acceptance.

Effluent water from recirculating aquaculture systems (RAS) contains nutrients from fish excrements and leftover feed. This study investigated the nutrient remediation potential from RAS effluent water through microalgae cultivation in 25 L tubular reactors. We compared nutrient uptake and biomass productivity in continuous and perfusion cultivation modes for freshwater, brackish water and saltwater. Stable high biomass densities were achieved with additional nitrate during continuous cultivation (up to 3.88 g L^-1) or by membrane filtration during perfusion cultivation (up to 3.59 g L^-1). A life cycle assessment (LCA) compared the two different cultivation modes in terms of environmental sustainability on a 1 ha scale. The LCA and preliminary economic assessment showed that perfusion cultivation appears to have a lower environmental impact for relatively low nutrient concentrations, but additional equipment and higher energy demands are leading to increased operational (+6 %) and capital expenses (up to +60 %).

The use of microalgae as a food ingredient has been gaining attention in recent years due to its nutritional benefits. The main goals of this study were to (i) assess the nutritional potential of Chlorella vulgaris, Tetraselmis chuii, Microchloropsis gaditana, and Phaeodactylum tricornutum; (ii) evaluate their bioactive properties (antioxidant activity, total phenolic content, and α-amylase inhibitory activity) and (iii) assess the main volatile compounds composition. The protein content was considerably high (32–44 mg/100 g dw) for all the microalgae strains. The DPPH scavenging potential range was 14–25 mg Trolox/100 g dw (highest for T. chuii) and the ferric reducing power ability range was 13–67 µmol Trolox/dw (higher for T. chuii). The total phenolic content range was 2–7 mg of gallic acid equivalents/g dw, for M. gaditana and T. chuii, respectively, which was mainly due to the presence of catechin (1–9 µg/g dw), epicatechin (3–29 µg/g dw), and vanillic acid (1–14 µg/g dw). The ɑ-amylase inhibitory potential range was 26–42%. C. vulgaris was richer in chlorophyll a (18 mg/g dw), whilst T. chuii was particularly rich in chlorophyll b (29 mg/g dw). P. tricornutum showed the highest carotenoid content (4 mg/g dw). Aldehydes and alkanes were the major compounds identified in M. gaditana, whereas alcohols and N-based compounds existed in higher amounts in P. tricornutum. T. chuii and C. vulgaris were enriched in ketones and alkenes. This study’s novelty lies in its comprehensive and integrative analysis of the nutritional, bioactive, and volatile properties of four distinct microalgae strains. By providing detailed comparisons and highlighting potential applications in functional foods, it offers a unique contribution to the field of microalgae research and its practical application in the food industry. This multifaceted approach sets it apart from existing studies, offering new insights and opportunities for leveraging microalgae as valuable food ingredients.

Background Climate change has been associated with fluctuations of environmental parameters such as salinity, which can affect growth rates, quality, and overall health of farmed organisms. Consequently, farming euryhaline fish can be a solution to build resilience of aquaculture to climate change. Euryhaline species can undergo notable physiological and behavioural changes in response to fluctuations in salinity levels and a dietary supplementation with microalgae extract has the potential to foster the salinity tolerance thanks to its antioxidant properties. Methods The trial was performed on a well-known euryhaline species, Lates calcarifer, reared at two different salinities, namely seawater (SW) and brackish water (BW), within a recirculating aquaculture system (RAS). The effect of supplementation with the microalga Microchloropsis gaditana liquid extract 3% w/v top coated on the feed, was also investigated. After ten weeks, the growth performance, the fillet quality, and the microbiome profile, were compared between four treatments (SW, SW+ M. gaditana, BW, BW+ M. gaditana). Results The FCR and feed intake showed a significantly higher value in fish reared in SW. The viscerosomatic index (VSI) was also higher in the SW treatment compared to the BW. There were no significant differences in growth between fish fed with M. gaditana supplement and fish without algal supplementation. Moreover, there were no significant differences in body colour intensity. The fatty acid profile was also assessed for the four treatments. The algal supplementation resulted in higher MUFA and TFA, and lower SAFA of fish reared in SW compared to BW. The analysis of the microbiome showed that changes in salinity strongly influenced the community composition in faeces and system compartments. Conclusions Overall, the results of this study indicate that barramundi can be reared successfully at different salinities without experiencing significant impact on growth, and should be considered to increase resilience of the aquaculture sector in a changing environment.

Rapid population growth, industrialization, and increasing energy demands have intensified environmental challenges, driven by raising wastewater and exhaust gas discharge. Along with fossil fuel depletion, more pressing energy needs have widely accelerated research into renewable energy sources, as well as diverse waste-to-value strategies, converting waste streams into biofuels, energy and commodity chemicals. Several approaches such as carbon capture and utilization (CCU), carbon capture and storage (CCS) and wastewater reuse are gaining meaningful attention to prompt carbon emission reduction and circular economy benefit. However, information available in literature about these sources is dispersed, and a dataset detailing the composition of these feedstocks is lacking, despite its potential to optimize bioprocesses such as gas fermentation, microbial electrosynthesis or microalgae cultivation. A dataset comprising distinct feedstock composition analyses is presented. The feedstocks are categorised into gaseous and liquid effluents and further classified according to the industrial processes from which they originate. The dataset was compiled through a systematic review applied to relevant articles published between the years 1990 and 2025, sourced from the Science Direct database.