This study aimed to investigate the effects of the probiotic Betaplus^® and prebiotic Technomos^® as feed additives for Nile tilapia in terms of growth performance, health profiles, and resistance to infection with Aeromonas hydrophila and Pseudomonas fluorescens. A total of 960 healthy juvenile Nile tilapia (1.5 ± 0.01 g) were randomly divided into four experimental variants with three replicates for each variant. Fish were fed a commercial diet (control group, V₀), supplemented with BetaPlus^® probiotics–1% × BW (V₁), TechnoMos^® prebiotics–1% × BW (V₂), and with BetaPlus^® probiotics and TechnoMos^® prebiotics in a ratio of 1:1% × BW (V₃). Results on growth performance showed the best values in the probiotic variant, correlated with the health profile and the relative survival percentage after the challenge test with A. hydrophila and P. fluorescens. Similarly, the effects of dietary supplementation with probiotics and prebiotics on physiological conditions also recorded beneficial results in the synbiotic variant, where a high survival percentage was obtained after infection with the two pathogenic bacteria. In conclusion, the results of this study indicate that dietary supplementation with feed additives consisting of mentioned probiotics, prebiotic, and their combination as synbiotics has the potential to promote growth performance, improving tilapia immunity and increasing survival after the challenge test.

The use of probiotics in aquaculture has become a necessity to increase disease resistance. Probiotics are also capable of increasing feed digestion and conversion, decreasing sensitivity to stress, and improving the health of the fish. The aim of this study was to analyse the effect of probiotics on survival, welfare, growth indices and blood composition in Siberian sturgeon (Acipenser baerii), reared in a recirculating system. Diets were supplemented with Lactobacillus acidophilus (FLa) and Saccharomyces boulardii (FSb), separately and combined (FLa + Sb). The effect of probiotics was investigated on 2000 fish with a mean weight of 8.82 ± 0.29 g/specimen. Fish were fed for eight weeks with four different diets: a control without probiotics, one with the addition of lactic acid bacteria (La), one with the addition of yeast (Sb), and one with a mixture of bacteria and yeast in equal proportions (50% La + 50% Sb). FLa + Sb showed a better condition factor (Fulton coefficient, K = 0.39%) and significantly higher growth performance in terms of individual growth (WGi = 35.56 g), total growth gain (WGt = 15.30 g), specific growth rate (SGR, 2.70%/day), and feed conversion ratio (FCR = 1.58), compared to the control. The concentration of lymphocytes, monocytes, and neutrophils was higher in the tanks fed with probiotics compared to the control. The presence of probiotics caused a decrease in cholesterol and glucose. There were significant differences between the Immunoglobulin M values identified in the tank fed with FLa + Sb and the control tank. The results showed that the addition of lactic acid bacteria and yeasts, introduced as probiotics in the diets of Acipenser baerii, reared in a recirculating system, improved the growth indicators, survival, and welfare of the fish.

Here, we aim to improve the overall sustainability of aquaponic basil (Ocimum basilicum L.)-sturgeon (Acipenser baerii) integrated recirculating systems. We implement new AI methods for operational management together with innovative solutions for plant growth bed, consisting of Rapana venosa shells (R), considered wastes in the food processing industry. To this end, the ARIMA-supervised learning method was used to develop solutions for forecasting the growth of both fish and plant biomass, while multi-linear regression (MLR), generalized additive models (GAM), and XGBoost were used for developing black-box virtual sensors for water quality. The efficiency of the new R substrate was evaluated and compared to the consecrated light expended clay aggregate—LECA aquaponics substrate (H). Considering two different technological scenarios (A—high feed input, B—low feed input, respectively), nutrient reduction rates, plant biomass growth performance and additionally plant quality are analysed. The resulting prediction models reveal a good accuracy, with the best metrics for predicting N-NO₃ concentration in technological water. Furthermore, PCA analysis reveals a high correlation between water dissolved oxygen and pH. The use of innovative R growth substrate assured better basil growth performance. Indeed, this was in terms of both average fresh weight per basil plant, with 22.59% more at AR compared to AH, 16.45% more at BR compared to BH, respectively, as well as for average leaf area (LA) with 8.36% more at AR compared to AH, 9.49% more at BR compared to BH. However, the use of R substrate revealed a lower N-NH₄ and N-NO₃ reduction rate in technological water, compared to H-based variants (19.58% at AR and 18.95% at BR, compared to 20.75% at AH and 26.53% at BH for N-NH₄; 2.02% at AR and 4.1% at BR, compared to 3.16% at AH and 5.24% at BH for N-NO₃). The concentration of Ca, K, Mg and NO₃ in the basil leaf area registered the following relationship between the experimental variants: AR > AH > BR > BH. In the root area however, the NO₃ were higher in H variants with low feed input. The total phenolic and flavonoid contents in basil roots and aerial parts and the antioxidant activity of the methanolic extracts of experimental variants revealed that the highest total phenolic and flavonoid contents were found in the BH variant (0.348% and 0.169%, respectively in the roots, 0.512% and 0.019%, respectively in the aerial parts), while the methanolic extract obtained from the roots of the same variant showed the most potent antioxidant activity (89.15%). The results revealed that an analytical framework based on supervised learning can be successfully employed in various technological scenarios to optimize operational management in an aquaponic basil (Ocimum basilicum L.)-sturgeon (Acipenser baerii) integrated recirculating systems. Also, the R substrate represents a suitable alternative for replacing conventional aquaponic grow beds. This is because it offers better plant growth performance and plant quality, together with a comparable nitrogen compound reduction rate. Future studies should investigate the long-term efficiency of innovative R aquaponic growth bed. Thus, focusing on the application of the developed prediction and forecasting models developed here, on a wider range of technological scenarios.

This study aimed to evaluate the growth, mortality parameters, and exploitation rate of Pontic shad, Alosa immaculata Benett, 1835, in the Danube River, Romania (km 169–197). The sampling collection started with the first signs of Pontic shad migration, on 4 March 2023, and continued weekly until the beginning of June 2023, when the last specimens were caught in the nets. The estimation of the growth, mortality parameters, and exploitation rate was done in FiSAT (FAO-ICLARM Stock Assessment Tools). The von Bertalanffy growth equation was estimated at L_∞ = 36.75 cm, the growth coefficient was k = 0.68 year⁻¹, and the theoretical initial age was t₀ = −0.67 year⁻¹. The total mortality rate (Z) estimated was 2.76 year⁻¹, with a natural mortality rate (M) and fishing mortality rate (F) of 0.89 year⁻¹ and 1.87 year⁻¹, respectively. The Z/k ratio was found to be 4.11 and the exploitation rate (E) was estimated at 0.68 year⁻¹, indicating the overexploitation of Alosa immaculata stocks. In conclusion, this study provides valuable insights into the population dynamics of Pontic shad in the Danube River, Romania. The assessments of the growth parameters, mortality rates, and exploitation rates highlight a level of overexploitation of Alosa immaculata stocks. These findings underscore the importance of applying effective fishery management strategies to ensure the sustainability and conservation of this valuable fish species in the Danube River ecosystem.

The aim of this research was to evaluate the health status of the Scophthalmus maeoticus (Pallas, 1814) population from the Romanian marine area in 2016–2019, by identifying and investigating information about bacterial and constitutional diseases, establishing the influence of these bacterioses on the researched populations, and highlighting the main biological disorders (reproduction, growth, and feeding) that manifested in the analyzed fish. The bacterial diseases reported in S. maeoticus (Pallas, 1814) populations were caused by pathogens from the genera Vibrio, Aeromonas, and Pseudomonas. Numerous skin diseases, especially various types of “wounds”, lesions of bony tubercles, and tissue lesions may be the subsequent cause of neoplasms, as a result of fishing gear manipulations. The appearance of significant changes in the prevalence of neoplasia on the Romanian Black Sea coast can be considered an indicator of chronic stress (anthropogenic impact), rather than acute (environmental impact), and we suggest that the species could be used as a biological indicator of changes that may occur in the habitat in which it lives. In terms of future research directions, a combined analysis of the population structure, morphology and diseases determined in S. maeoticus populations, with a structural analysis of the habitat and bacteria contamination degree would be useful; this monitoring should be carried out regularly, to reveal changes in the Black Sea ecosystem, and to propose possible recommendations and protective measures.

A field experiment was conducted during 2015-2019 years at the National Agricultural Research and Development Institute Fundulea, Romania, to investigate the effect of different nitrogen and phosphorus sources on growth, yield and quality of maize (Zea mays L.). This research is carried out in long term experiments (over 45 years) under unirrigated conditions. Fertilization, like the basic technological link, ensures a constant flow of nutrients to the crop plant, but the efficiency of applying organic fertilizers is strongly influenced by extreme variations of the climatic conditions. The results showed also that the final maize yields and yield increases were conditioned and limited by specific traits, especially using of mineral and organic fertilizing.