Search Results (44)

This paper presents a prototype of an autonomous hydrochemical monitoring system developed for large freshwater aquaculture facilities, directly addressing the need for smart monitoring in Agriculture 4.0. The proposed solution employs low-power sensor nodes based on commercially available components and long-range LoRaWAN communication to achieve continuous, scalable, and energy-efficient water quality monitoring. Each sensor module performs on-board signal preprocessing, including anomaly detection and short-term forecasting of key hydrochemical parameters. An ecological pond dynamics model incorporating an Extended Kalman Filter is used to fuse heterogeneous sensor data with predictive estimates, thus increasing measurement reliability. High-level data analysis, long-term storage, and cross-site comparison are performed on the server side. This integration enables adaptive tracking of environmental variations, supports early detection of hazardous trends associated with fish mortality risks, and allows one to explain and justify the reasoning behind every recommended corrective action. The performance of the forecasting and filtering algorithms is evaluated, and key system characteristics—including measurement accuracy, power consumption, and scalability—are discussed. Preliminary tests of the system prototype have shown that it can predict the dissolved oxygen level with $RMSE$ = 0.104 mg/L even with a minimum set of sensors. The results demonstrate that the proposed conceptual design of the system can be used as a base for real-time monitoring and predictive assessment of hydrochemical conditions in aquaculture environments. Full article

China’s coastal wetlands play a crucial role in maintaining biodiversity and providing essential ecosystem services. However, the absence of high-resolution wetland type maps poses substantial challenges for effective conservation and management. This study proposes a two-step classification framework that integrates pixel-based Random Forest algorithms with object-based hierarchical decision trees, utilizing Landsat-8 time-series imagery to generate a detailed wetland map comprising 10 wetland types and 5 non-wetland categories. The results reveal distinct spatial patterns along China’s coastline: freshwater wetlands and riverine systems dominate the northern regions, whereas southern coastal zones feature extensive tidal flats, aquaculture ponds, and mangrove ecosystems. The proposed method achieved an overall accuracy of 89.76% and a Kappa coefficient of 0.891, demonstrating its effectiveness for large-scale wetland mapping. This study provides robust technical support for the sustainable conservation and ecological management of coastal wetlands. Full article

The increasing demand for sustainable aquafeeds necessitates the development of alternative protein sources that support both economic efficiency and ecological responsibility. This study evaluates the potential of using hempseed meal (a nutrient-dense agro-industrial by-product) as a functional ingredient in carp aquaculture diets. The paper presents a proof-of-concept evaluation demonstrating the potential of hempseed meal as a circular bio-ingredient that aligns with the principles of sustainable aquaculture, rather than providing a comprehensive assessment of its long-term physiological effects on fish. A 90-day feeding trial was conducted under controlled pond conditions to assess the effects of graded hempseeds meal inclusion levels on growth performance, feed utilization, and environmental sustainability indicators for three Cyprinus carpio varieties. Four isonitrogenous and isoenergetic diets were formulated: a control diet (R1) based on conventional plant protein sources such as soybean and pea meal, and three experimental diets containing 5%, 10%, and 20% hempseed meal (R2–R4). Growth indices including absolute weight gain (WG), average daily gain (ADG), specific growth rate (SGR), and feed conversion ratio (FCR) were determined, and data was analyzed via two-way ANOVA with Tukey HSD post hoc testing. Results indicated that 10% hempseed meal inclusion produced optimal growth responses, improving specific growth rate by 12.6% and reduced feed conversion ratio by 10.8% compared to the control. The most pronounced effects were observed for Frăsinet carp variety (SGR 1.23%·day⁻¹; FCR 1.39). Environmental assessments demonstrated that substituting conventional protein sources (soybean and pea meal) with hempseed meal at 20% inclusion valorized 200 kg of hemp press cake per ton of feed, reduced conventional protein use by 33.3%, diverted up to 80% of waste from disposal. These findings validate hempseed meal as a sustainable, cost-effective, and nutritionally viable alternative to conventional protein sources in freshwater aquaculture, advancing circular bioeconomy strategies and supporting low-carbon fish production systems. Full article

Mandarin fish (Siniperca chuatsi) is a highly valued freshwater species in China, owing to its high-quality meat and economic importance. This study comparatively evaluated the effects of an industrialized recirculating aquaculture system (RAS) and traditional pond aquaculture system (TPAS) on the muscle quality and further explored the role of gut microbiota in muscle quality regulation. Our results showed that the RAS resulted in superior textural properties, with meat that was significantly more tender and elastic. The RAS also promoted higher muscle protein and reduced lipid levels. Notably, the RAS elevated sweet-tasting amino acids (Gly and Pro) while suppressing bitter amino acids (His). Electronic nose and GC-iMS analyses revealed distinct flavor compound profiles between the two systems, and the RAS enriched desirable volatiles (esters and alcohols) while suppressing aldehydes (e.g., nonanal and heptanal) associated with off-flavors. Gut microbiota profiling indicated higher diversity and enriched beneficial genera (e.g., Cetobacterium, Lactobacillus) in RAS-treated fish. We found that the Cetobacterium in the RAS group showed a significant positive correlation with sweet amino acids and pleasant flavor substances (such as esters, alcohols), while exhibiting a negative correlation with undesirable flavor precursors (such as certain aldehydes). This finding contributes to the sustainable and high-efficiency advancement of intensive Siniperca chuatsi aquaculture. Full article

Antibiotic use in aquaculture has become widespread to sustain production and control bacterial diseases, but it poses significant ecological and human health risks due to residue accumulation and resistance development. This study investigated the occurrence, dominance, and combined use of sulfonamide and fluoroquinolone antibiotics in freshwater fish aquaculture ponds around Wuxi, China. Here, the term aquaculture refers specifically to the controlled farming of freshwater fish species such as carp and crucian carp in managed pond systems. A total of 80 water samples (collected exclusively from pond waters) were obtained from 40 ponds during the high intensity rearing and harvest stage of fish. Residues of enrofloxacin and sulfonamide antibiotics were analyzed using a validated LC–MS/MS method with detection limits in the low nanogram-per-liter range. Results revealed that antibiotics were ubiquitous in pond waters, with enrofloxacin emerging as the dominant compound in August, reaching concentrations of up to 2.36 µg/L. By October, sulfonamides, particularly sulfamethoxazole and sulfadiazine, became more prevalent, with a maximum sulfadiazine concentration exceeding 4 µg/L. Multivariate analyses demonstrated a clear seasonal shift in antibiotic profiles, while correlation analyses indicated limited combined use in summer but notable co-occurrence of sulfonamides in autumn. These findings underscore that antibiotic application patterns in aquaculture are strongly linked to production stages, with potential consequences for environmental safety, resistance development, and food security. Effective monitoring, stricter regulation, and alternative disease management strategies are urgently required to mitigate risks and promote sustainable aquaculture practices. Full article

CIFA-GI Scampi^® is a genetically improved, fast-growing strain of giant river prawn (Macrobrachium rosenbergii) developed by ICAR-Central Institute of Freshwater Aquaculture. Each year, selected broodstock are reared family-wise in nylon hapas for 3–4 months before use as parents for the next generation. However, this group rearing phase (GR) results in loss of quality broodstock due to aggression and cannibalism. This study evaluated individual rearing (IR) as an alternative to group rearing (GR). GR involved rearing of males or females in separate hapas, while IR placed males and females in separate hard plastic mesh boxes in ponds (18 boxes each). Results showed significantly higher average daily weight gain in GR, but IR achieved 100% survival for both sexes, compared to 50% (males) and 77.8% (females) in GR. No significant differences were observed in female maturity or male morphotypes (small male and no claw morphotypes). Given the markedly higher survival in IR, it is a viable alternative for post-selection rearing to minimize loss of valuable broodstock in the selective breeding program. Full article

The intensive farming of aquaculture species such as red tilapia (Oreochromis spp.) across diverse production systems can lead to changes in genetic parameters and responses of economically important traits in this species. This study represents the first attempt to understand these changes in growth traits (body weight, total length), quality attributes (body colour), and survival rate in red tilapia. Data for these traits were collected from 75,950 individual fish, progeny of 970 full-sib families (comprising 970 dams and 486 sires); they were selected for high body weight and evaluated in two distinct culture environments: fresh- and saltwater ponds. A multi-trait mixed model was employed to estimate genetic parameters and selection responses. Genetic variance estimates for the quality and survival traits varied across the two environments. However, genetic correlations among the traits studied were similar between fresh and saline water. Furthermore, significant G × E interactions, particularly for the quality and survival traits, were evidenced by divergent genetic correlations (r_g = 0.57–0.83) between homologous traits across different environments. The findings emphasise the importance of incorporating G × E interactions into the selection program for red tilapia, particularly when the breeding objectives extend to include quality and survival traits. Selection strategies should consider the prevailing culture system—for instance, favouring genotypes suited to the freshwater pond environment over those adapted to the saltwater environment. Continual assessment of full-sib groups across these environments is recommended to refine our understanding of G × E interactions and optimise future breeding programs for red tilapia. This may involve selecting genotypes capable of consistent performance across environments or developing environment-specific breeding programs. Full article

Background/Objectives: Motile aeromonads are ubiquitous aquatic Gram-negative opportunistic pathogens with environmental, animal, aquatic, and human health implications. Methods: Motile aeromonads were isolated from village pond water samples (n = 100) of the Hisar district of Haryana state in India. Selective isolation and enumeration were followed by biochemical and genotypic identification using gyrB gene; evaluation of seven putative virulence factors and antimicrobial resistance studies and determination of extended spectrum beta lactamase (ESBL) and AmpC beta lactamase (ACBL) enzyme-producing abilities took place. Results: The viable counts of motile aeromonads varied from 1.6 × 10² CFU/mL to 1.2 × 10⁸ CFU/mL. Six species of Aeromonas were identified with high prevalence of A. veronii (74.7%), followed by A. caviae (8.9%), A. hydrophila (7.6), A. jandaei (5%), A. sobria (2.5%), and A. dhakensis (1.3%). PCR amplification of seven genes related to virulence indicated that the majority of the isolates were positive for enolase (eno, 98%), cytotoxic enterotoxin (act, 88%), and hemolysin (asa1, 86%). Many isolates were also positive for type III secretion system inner membrane component (ascV, 53%), ADP-ribosylating toxin (aexT, 47%), and extracellular hemolysin (ahh1, 4%). The antimicrobial resistance (AMR) profile of the isolated Aeromonas isolates indicated the high resistance observed to nalidixic acid (40.2%), cefoxitin (33%), and imipenem (6.2%). In addition, the occurrence of 10.3% ESBL, 32% ACBL, and 29.9% multi-drug resistant (MDR) isolates is alarming. Phylogenetic analysis of gyrB sequences of A. veronii isolates (n = 59) together with GenBank sequences of A. veronii from different geographical regions of the world indicated high genotypic diversity. Conclusions: the village aquaculture ponds in Hisar district have a high occurrence of MDR A. veronii, A. hydrophila, and A. caviae, posing significant animal and public health concern. Full article

An adaptable, low-cost, and easy-to-operate biological treatment system for pollutant abatement in aquaculture water at the field pond scale needs to be developed. In this study, the pollutant removal capacity of a stable bioreactor for aquaculture wastewater was assessed, and the related mechanism was elucidated via an analysis of the microbial community’s characteristics and functions. The average removal efficiencies of chemical oxygen demand, suspended solids, total nitrogen, and total phosphorus were 40%, 86.22%, 38.62%, and 53.74%, respectively. The effluent quality meets the Requirement for Water Discharge from Freshwater Aquaculture Pond, SC/T9101-2007. The results indicate that the fillers under anaerobic conditions could attract Denitratisoma and unclassified_Rhodocyclaceae, promoting the denitrification reaction. This aligns with the characteristic that total nitrogen in aquaculture sewage mainly exists in the form of nitrate nitrogen. An anaerobic atmosphere helps degrade organic contaminants at liquid interfaces and remove nitrogen in the solid phase. The fillers under anaerobic conditions could attract Bacteroidota and promote the production of polysaccharides to form biofilms, which may be associated with phosphorus removal. The results indicate that the anaerobic stage can promote the formation of biofilm on the fillers to remove pollutants, thus achieving higher aquaculture sewage treatment efficiency. Full article

Ichthyophthirius multifiliis, a parasitic ciliate, causes “white spot disease” in freshwater fish and poses a significant threat to global freshwater aquaculture. Eliminating the free-swimming theront stage from the aquaculture environment is a critical measure for controlling I. multifiliis infections. The natural predator of I. multifiliis theronts in fish-farming ponds were identified using fluorescent dye-labelled live theronts and quantitative PCR; meanwhile, the zooplankton community composition in the positive ponds of I. multifiliis detected by quantitative PCR were analyzed by eDNA metabarcoding assay. The results revealed predation on theronts by cyclopoid copepods, including Cyclops vicinus, Thermocyclops taihokuensis, Cyclops sp., Thermocyclops sp., Eucyclops sp., and Mesocyclops sp. from the in-situ predation aquatic ecosystem, and among these copepods, C. vicinus was identified as a natural dominant predator of I. multifiliis. This study provides a scientific basis for further exploration and utilization of natural predators to enhance sustainable and environmentally friendly control strategies against I. multifiliis. Full article

Giant freshwater prawn (Macrobrachium rosenbergii) farming in Bangladesh began in the 1970s and has become a significant export industry. Despite its potential, there are concerns about the environmental sustainability of prawn farming due to its high greenhouse gas (GHG) footprint, but implementation of integrated multi-trophic aquaculture (IMTA) may help minimize the GHG emission. A key element in IMTA is using plants to take up inorganic nutrients released by the prawns, producing valuable plant products and cleaning the water. Using a quadrat sampling method, we conducted a field study in combined prawn and shrimp ponds, aquaculture fishponds, and non-aquaculture waters in south- west Bangladesh to characterize plant diversity and identify suitable species for IMTA in prawn farms. A total of 38 plant species were identified with densities ranging from 4.5–6.1 plants/m² in the aquaculture ponds to 11.6–17.1 plants/m² in the prawn/shrimp and the non-aquaculture ponds. Free-floating plants were the most abundant, followed by emergent, floating anchored, and submerged plants. Most plants have commercial values as food, fodder, fish feed, fertilizer, or medicines to local people. Our results suggest that species within the Oxalis, Ipomoea, Azolla, and Lemna genera are suitable extractive aquatic plants for the implementation of IMTA in prawn farms and may improve the sustainability of prawn production. Full article

Aquaculture is a rapidly growing industry that contributes to the growing global demand for food. Numerous studies have investigated the necessity of increasing food production while reducing its negative effects on the environment. Aquaculture involves the cultivation of aquatic animals such as fish, shrimp, and mollusks that require water for their growth and maintenance in various types of aquaculture operations, such as recirculated aquaculture systems (RASs), ponds, and sea cages. This study investigates mainly life cycle assessment (LCA) in relation to water consumption, the water footprint (WF) and water budgeting approaches in aquaculture. In addition, it contributes to the expansion of knowledge and understanding of the different methodologies used, production practices, types of water (freshwater, marine or brackish) and direct or indirect water consumption in intensive, semi-intensive and extensive types of aquaculture. Notably, this study focuses on water consumption and does not include water indices that account for all the water used in a system, regardless of whether it is returned to the sourced watershed and is therefore available for other uses. Approximately 15% of the reviewed studies focus on the fish processing stage of the production chain, which emphasizes the need for more research on this stage. The species of carp, tilapia, shrimp, and catfish are the most frequently studied aquatic animals in relation to water consumption in aquaculture. Research on water consumption patterns can contribute to the development of a more water-efficient aquaculture system that is essential for promoting sustainable practices. Full article

Steroid hormones, recognized as emerging environmental contaminants, have garnered increasing attention in recent years. The present work studied the distribution characteristics in the environment, bioaccumulation in aquatic products, and the associated environmental and health risks of typical steroid hormones from commercial freshwater aquaculture farms operating under different aquaculture modes (monoculture and polyculture). Totals of 9 and 14 steroid hormones were detected in water and sediment samples, with concentrations ranging from 0.66 ± 0.17 ng/L to 40.5 ± 5.08 ng/L and from 0.36 ± 0.08 ng/g to 123 ± 19.9 ng/g, respectively. Hazard index (HI) calculations indicated that all sampling locations were identified as medium or high risk for both water and sediment matrices. Nineteen steroids were detected in at least one type of tissue, with the concentrations in the bile, plasma, muscle, liver, and gill ranging from <LOQ to 52.6 ± 4.82 ng/L, from <LOQ to 41.9 ± 4.80 ng/L, from 0.36 ± 0.07 ng/g to 321 ± 19.1 ng/g, from <LOQ to 1140 ± 107 ng/g, and from 0.36 ± 0.03 ng/g to 1450 ± 239 ng/g, respectively. Furthermore, four synthetic steroid hormones exhibited significant bioaccumulation across various tissues, such as MLA in bile and 5α-DHP in muscle, liver, and gill (BAF > 5000 L/kg). Notably, despite low estimated daily intakes (EDIs) (0.43–6.43 ng/day/person to 18.7 ng/day/person) and hazard quotients (HQs) (below 4.188 × 10⁻⁷), the high bioaccumulation factors (BAFs) underscore the necessity for stringent regulatory measures by local governments. Additionally, a comparison of EDI results across different aquaculture modes and fish species revealed that steroid hormone-related health risks to humans are influenced by both the fish species and the aquaculture mode. This study indicated that the consumption of poly-cultured fish (e.g., bighead carp) may pose a greater steroid-related health risk, compared to the consumption of mono-cultured fish. Full article

Aquaculture is increasing globally, providing protein to a growing population, but little is known regarding the nutrient budgets in aquaculture. To obtain insight into how management practices impact nutrient fluxes in freshwater aquaculture earthen ponds worldwide, we conducted a literature review. Our literature search yielded 23 papers in which nutrient budgets were reported. Our results showed that the main nutrient inputs are inlet water, feed, and fertilizers, but they varied according to location and management practices. Overall, feed and fertilizers constituted the predominant nutrient sources, accounting for up to 99% of the total inputs. The most quantified outputs were outlet water, fish, and sedimentation. Our findings indicate that only up to 20% of carbon, 45% of nitrogen, and 60% of phosphorus are assimilated by the fish. In some systems, up to 80% of carbon, 80% of nitrogen, and 60% of phosphorus accumulate in pond bottoms; in other systems, the outflow represents substantial losses of up to 16% of carbon, 76% of nitrogen, and 55% of phosphorus. More insight into nutrients’ fate in fishponds is crucial from a sustainability perspective, as feed and fertilizer use can likely be optimized, reducing operational costs and the potential impact on the surrounding environment and atmospheric greenhouse gas concentrations. Full article

The Chinese soft-shelled turtle (Pelodiscus sinensis) is an important freshwater aquaculture turtle due to its taste and nutritional and medicinal value. More ecological culturing modes, such as rice–turtle co-culture, should be developed to meet the ecological benefit demand. We compared growth, physiological parameters, and transcriptome data to detect the physiological responses and regulatory mechanisms of pond-cultured turtles as compared to co-cultured turtles. The co-cultured turtles grew slower than pond-cultured turtles. The gonadosomatic index of co-cultured male turtles was lower than that of pond-cultured male turtles, and both the mesenteric fat index and limb fat index were lower in co-cultured turtles than in pond-cultured turtles (p < 0.05). The blood GLU of the co-cultured turtles was significantly lower than the GLU of the pond-cultured turtles (p < 0.05), while the values of CRE, UA, BUN, AKP, ACP, GOT, and CAT were higher in the co-cultured turtles than in the pond-cultured turtles (p < 0.05). In total, 246 and 598 differentially expressed genes (DEGs) were identified in the brain and gut from turtles cultured in the two different modes, respectively. More DEGs were related to environmental information processing, metabolism, and human diseases. In the brain, the top enriched pathways of DEGs included the longevity regulating pathway, glycerolipid metabolism, cytokine–cytokine receptor interaction, Toll-like receptor signaling pathway, and PI3K-Akt signaling pathway, while in the gut, the top enriched pathways of DEGs included the cell cycle, DNA replication, cellular senescence, and p53 signaling pathway. The turtles acclimated to the different culturing conditions by adjusting their growth, physiological, and biochemical characteristics and related gene expression during a short culture period. Full article