This paper provides a comparative overview of decadal changes in aquaculture production in the European Union (EU-27) and Latin America and the Caribbean (LAC). Contrary to other regions of the world, freshwater fish farming in these two territories is a marginal sub-segment of the aquaculture sector. Using an indicator-based approach, we track development tendencies in freshwater aquaculture, focusing on the main established and emerging species, diversification, and shifts in the mean trophic level of farmed animals. Geographical patterns in production trends are revealed in both regions. The study attempts to explain between-region and between-country differences in aquaculture growth by analyzing freshwater resource endowments at region-level and country-level, using total renewable water resources (TRWR) as an indicator of water-abundancy. Thermal optimum of main produced species is matched against climate conditions prevailing in main producer countries to provide further understanding of spatial heterogeneity in growth rates of aquaculture sector.

In the EU, aquaculture ponds cover an area of 360,000 ha and are a crucial part of the rural landscape. As many ecosystem services (e.g., habitats for protected wildlife, nutrient cycling, etc.) are correlated with the proportion of reed beds relative to open-water areas, it is important in environmental studies to be able to accurately estimate the extent and the temporal dynamics of reed cover. Here, we propose a method for mapping reed cover in fish ponds from freely available Sentinel-2 imagery using the normalized difference vegetation index (NDVI), which we applied to Hungary, the third largest carp producer in the EU. The dynamics of reed cover in Hungarian fish ponds mapped using satellite imagery show a high degree of agreement with the ground-truth points, and when compared with data reported in the annual aquaculture reports for Hungary, it was found that the calculation of reed cover based on the NDVI-based approach was more consistent than the estimates provided in the report. We discuss possible applications of this remote sensing technique in estimating reed-like vegetation cover in fish ponds and the possible use of the results for climate change studies and ecosystem services assessment.

A 7-week feeding trial was conducted with Nile tilapia juveniles with an average body weight of 143.5 ± 3.1 g in a cage system in order to test the effect of different feed additives on growth performance, antioxidant defense system, and immune status of fish. For this reason, experimental diets were formulated with inclusion of two different additives containing bioactive compounds, namely Nannochlorophsis gaditana in 3.5% (diet EXP-A) and black soldier fly larvae meal (diet EXP-I) in 3.5%, and compared with a diet supplemented with a mixture of two different commercial compounds (Yang and Syrena Boost) in 0.4% (diet EXP-S). As a negative control, a commercially available feed (Nongteng, Laos) for tilapia was selected. At the end of the feeding trial, production parameters and expression of genes related to the antioxidant defense system and innate immune response were studied. Furthermore, following the feeding, air exposure stress for 5 min was administered to the fish, and similar parameters were assessed. Results indicated that all diets promoted adequate fish growth (SGR 1.67–1.81 g day⁻¹) and feed utilization (FCR 1.29–1.57 g g⁻¹) with no significant (p < 0.05) differences in these parameters between the dietary fish groups. Expression of genes sod, cat, and gpx significantly increased in the liver samples of the EXP-A group at the end of feeding. Following air exposure, the EXP-A group maintained a significantly higher level of antioxidant-related gene expression compared to other treatments. Subsequently, gpx upregulation was observed in the EXP-S group in the post-stress stage compared to pre-stress. Based on our results, we recommend the inclusion of any of the tested additives at the evaluated doses to enhance the non-specific immune response of Nile tilapia. Additionally, Nannochloropsis gaditana at a 3.5% inclusion level can be used to further improve antioxidant defense capacity.

This research aimed to evaluate the reproductive potential of hatchery-reared (F1) pike-perch (Sander lucioperca) broodstock fed a commercial diet with low levels of long-chain polyunsaturated fatty acids (Lc-PUFA) and wild (F0) pike-perch broodstock fed forage fish. Reproductive parameters, including pseudogonadosomatic index (PGSI), egg size, latency time, hatching rate, embryo survival, and eggs’ fatty acid (FA) composition, as well as plasma sex hormone, glucose and immunoglobulin levels after hormone injection, were analyzed. The results showed low PGSI (10% in F1 vs. 14% in F0) and embryo survival (24% in F1 vs. 61% in F0) in F1 broodstock, but a satisfactory hatching rate (63% in F1 vs. 78% in F0) and larval size (4.6 mm in F1 vs. 4.7 mm in F0). A low arachidonic acid (ARA) percentage in F1 fish eggs (1.32%), along with increased immunoglobulin levels (17.31 g/L), suggests that immune system activation might have depleted the reserves of ARA in F1 fish, which is the key fatty acid for successful oocyte maturation. We assumed that the administration of more sustainable diets, based on terrestrial plant ingredients, is not inferior to higher-quality diets based on marine ingredients.

Marine biomass represents a nutrient-rich and underutilized resource with significant potential to contribute to the alternative protein transition. In the European Union (EU), the valorization of marine by-products aligns with strategic objectives related to circularity, resource efficiency, and the blue bioeconomy. This study investigates stakeholder perspectives on the use of marine by-products for food and feed applications across five EU countries (Germany, Hungary, Poland, Portugal, and Spain). Qualitative data were collected from 62 stakeholders representing diverse positions along the food and feed value chains, including primary production (aquaculture and mixed farming), food processing and manufacturing, feed and animal nutrition, ingredient supply, research institutions, innovation actors, and industry associations. A deductive thematic analysis examined key domains such as functionality, sustainability, cost, regulation, and consumer acceptance. Findings indicate that adoption is not driven by a single determinant, such as sustainability appeal or consumer demand. Rather, marine-based protein integration emerges from the sequential alignment of technical feasibility, regulatory legitimacy, economic viability, and socio-cultural acceptance. Based on these insights, a stakeholder-derived adoption pathway is proposed. The framework also highlights cross-cutting enablers such as innovation capacity, research–industry collaboration, financial investment, regulatory guidance, and knowledge dissemination. The cross-country convergence of results suggests that adoption barriers are largely structural rather than country specific. By integrating technical, institutional, economic, and socio-cultural dimensions, this study advances understanding of marine-based proteins within broader sustainability transition processes and provides a systems-oriented framework to inform policy and innovation strategies.

Laos is one of the 32 landlocked developing countries (LLDCs) of the world, where isolation from the sea and the lack of a large-scale fishing industry have a direct effect on fish supply and fish consumption. Per capita fish consumption in LLDCs amounted to 5.1 kg/year in 2023, which is much lower than the world average (20.3 kg) as well as the Developing Regions average (20.0 kg). However, per capita fish consumption in Laos has reached 28.5 kg/year in 2023, representing the highest among the 32 LLDCs. Relying on the results and experiences of several decades of work in aquaculture development in Laos and taking into account the observations of local and international publications, documents and statistics included, the authors aimed at identifying the principal reasons for the elevated fish consumption in Laos from different perspectives, including that of aquaculture, as well as Lao language, culture, and religion. In this review, the authors analyzed the availability of aquatic resources, the role of fishing and aquaculture in the Lao economy and social life, market realities, as well as the importance of fish in Lao culture.