Search Results (2,227)

Aquaculture requires continuous environmental monitoring, yet low-cost IoT sensing in marine conditions remains poorly characterised, and the data it produces is rarely accompanied by mechanisms establishing its provenance. This paper presents an IoT sensor system for marine and coastal aquaculture, comprising solar-powered 4G multiparameter nodes, a cloud-native back-end with a RESTful layer, and integration with a blockchain-based change-detection mechanism supplying a GS1-compliant digital product passport. Four nodes in adjacent cages were deployed at a marine site on the Montenegrin Adriatic for eight weeks, measuring temperature, pH, dissolved oxygen, oxidation–reduction potential and conductivity at five-minute resolution. Lacking reference instrumentation, we use agreement between nodes for validation. Temperature showed the closest cross-node agreement, with nodes agreeing to within 0.28 °C, and resolved a coherent cold, low-salinity intrusion detected simultaneously by all four nodes. The electrochemical and optical channels proved precise but not accurate: they tracked relative change coherently while their absolute values diverged, with oxidation–reduction potential moving from 9 mV of agreement to 71 mV over the following weeks. Cross-node coherence in conductivity and dissolved oxygen degraded progressively over the deployment, with no electrochemical or optical channel remaining coherent beyond roughly six weeks. Such sensors suit anomaly detection without calibration but require periodic recalibration for absolute reporting. Tamper-evident provenance is therefore necessary but not sufficient: sensor-level quality assurance is its missing half. Full article

Respiratory metabolism reflects energy demand and physiological variation in bivalves, but interpretation of among-population differences requires careful consideration of developmental stage, diet, breeding background, and previous rearing history. In this study, oxygen consumption rate (OR), ammonia excretion rate (NR), O:N ratio, and key metabolic enzyme activities were compared among three Manila clam (Ruditapes philippinarum) populations: Laizhou wild-origin stock (LZ), Fujian-origin stock cultured in Liaoning (FJ), and Zebra shell-color selected line (ZS). These populations were selected to represent three common germplasm categories used in Manila clam production: a wild-origin stock, a translocated aquaculture stock, and a Zebra shell-color selected line. Clams with nominal shell lengths of 10, 15, and 20 mm were used for respiratory measurements, and enzyme activities were determined in 15 mm individuals. Two-way ANOVA revealed significant effects of population on OR, NR, and O:N ratio (p < 0.05), whereas shell length significantly affected NR and O:N ratio (p < 0.05). OR decreased with increasing shell length in LZ and FJ, while ZS showed a different pattern. NR generally declined with shell length across all populations. The O:N ratio increased markedly in LZ but remained relatively low in FJ and ZS. Among enzyme activities, SDH was significantly higher in LZ (p < 0.01), whereas AKP activity was highest in ZS (p < 0.05). LDH activity did not differ significantly among populations. These results demonstrate that Manila clam populations with different source backgrounds exhibit distinct physiological profiles under standardized laboratory conditions. The observed variation represents population-associated physiological characteristics rather than direct evidence of genetic differentiation, providing baseline information for future germplasm characterization integrating physiological, genetic, and environmental approaches. Full article

Aquaculture has emerged as one of the fastest-growing sectors of global food production, driven by population growth, consumer demand, and technological innovation. Despite this expansion, the industry continues to face persistent challenges, including disease management, optimizing growth and product quality, maintaining water quality, and mitigating environmental impacts. Nanotechnology has recently emerged as a promising tool to tackle these issues, offering both direct applications, such as antimicrobial agents, immunostimulants, and optimized drug delivery to enhance fish health, and indirect applications, including post-harvest processing, environmental monitoring, and contaminant removal. This review provides a comprehensive overview of nanoparticle applications in aquaculture from 2020 to early 2026, covering the various types of nanoparticles, their mechanisms of action, and the specific materials investigated during this period. The discussion also addresses potential benefits, limitations, and biosafety concerns, emphasizing the need for further in vivo and field studies to ensure the safe and sustainable integration of nanotechnologies into aquaculture practices. Full article

The 1st International Online Conference on Environments addresses issues of environmental understanding, management, and restoration. Sessions ranged from general frameworks to a broad area of specific investigations: heavy metal removal using inactive yeast, gadolinium’s aquatic toxicity, adsorptive removal of pollutants, energy recovery from waste and wastewater treatment, recycled carbon fibers, climate-resilient urban development, renewable biofuel production, green hydrogen, anthropogenic and volcanic CO₂ emissions, quantifying aging dignity in urban ecosystems and stray dogs as pollution health sentinels. Keynotes covered digital plant phenotyping for restoration, microplastic dynamics, agricultural residue management, carbon credits, air quality, atmospheric pollution, transitional waters, green chemistry, ecotoxicity, micropollutants, and coastal darkening effects on plankton, among others. Applied solutions included phytoremediation of eutrophication in urban streams, circular approaches in aquaculture, biochar for wastewater treatment, AI-assisted mangrove monitoring, and true-cost accounting for food systems. The conference demonstrated that effective environmental policy requires the integration of laboratory findings, field restoration, and shared resource responsibility across terrestrial and marine ecosystems. Full article

Hypoxia is a significant environmental and production-related stressor in Atlantic salmon aquaculture, yet the blood-based mechanisms underlying differential hypoxia tolerance remain poorly characterized. In this study, we examined hematological, biochemical, and transcriptional responses in Atlantic salmon parr classified as hypoxia-tolerant or hypoxia-susceptible following an acute progressive hypoxia challenge. Time to loss of equilibrium and dissolved oxygen concentration at loss of equilibrium were recorded. Blood samples were analyzed for hematological parameters, serum metabolites, and the expression of genes related to hypoxia signaling, glycolysis, oxidative stress, and immune regulation. Hypoxia-tolerant fish maintained equilibrium significantly longer than susceptible fish (Tolerant: 224 ± 18 min; Susceptible: 115 ± 24 min) and tolerated lower dissolved oxygen concentrations (Tolerant: 1.89 ± 0.09 mg L⁻¹; Susceptible: 2.55 ± 0.34 mg L⁻¹) before losing their ability to maintain equilibrium. Tolerance varied among families, while body weight was not significantly associated with time to loss of equilibrium. Acute hypoxia altered erythrocyte-related parameters, increased serum lactate (p < 0.0001), and reduced total protein (p = 0.0148) in both phenotypes. At the transcriptional level, tolerant fish exhibited higher expression of hif1α (p = 0.0012), k6pp (p = 0.0045) and il15 (p = 0.0159), along with reduced phd3 (p = 0.0317) expression, whereas susceptible fish showed increased anx1 expression. Taken together, our results showed that hypoxia tolerance in Atlantic salmon is associated with a coordinated blood response involving metabolic compensation and hypoxia-responsive signaling, supporting the use of blood as a practical tool for identifying resilient fish. Full article

Copepods are widely recognized as biologically superior live prey for many marine fish larvae, yet their routine large-scale production remains a major bottleneck in aquaculture. Within this context, the harpacticoid genus Tigriopus has attracted increasing attention because it combines broad environmental tolerance, ease of culture, and promising nutritional and biotechnological value. This review critically examines the current state of knowledge on the genus Tigriopus, with particular emphasis on its aquaculture relevance, while integrating the biological, ecological and ecotoxicological framework needed to interpret the specific case of the Mediterranean species T. fulvus. The available literature shows that in aquaculture, the potential of this copepod genus is supported by complementary evidence across species. T. californicus currently provides the strongest proof of concept for pilot-scale biomass production and biochemical valorization, particularly as a source of omega-3- and astaxanthin-rich biomass. T. japonicus contributes most clearly to culture optimization and live-feed application, especially with respect to feeding performance and stocking-density effects. Tigriopus fulvus, in contrast, remains an earlier-stage but credible Mediterranean candidate, showing promising diet-dependent naupliar production and survival, although its culture technology is still underdeveloped. Overall, Tigriopus should be regarded as a genus of growing relevance for aquaculture, not only as live prey but also as a potential source of functional biomass. Future progress will depend on improved mass-culture methods, feeding optimization, harvesting efficiency, and a comparative species-level framework linking biological traits to specific aquaculture applications. Full article

The Markakol lenok, Brachymystax savinovi, is an endemic salmonid inhabiting Lake Markakol and its tributaries in eastern Kazakhstan. Over the past century, both abundance and population structure of this taxon have been influenced by natural and anthropogenic factors, highlighting the need for updated assessments of its conservation status. This study evaluated the current population condition, habitat characteristics, and conservation prospects during 2020–2024. Results indicated that Lake Markakol maintained favourable hydrochemical and hydrological conditions during 2020–2024, with no evidence of substantial ecological degradation. The Markakol lenok population was characterised by the predominance of intermediate age classes, positive allometric growth, satisfactory condition factors, and a substantial proportion of mature individuals, indicating relatively stable population status and preserved reproductive potential. In addition, broodstock and replacement populations established under aquaculture conditions showed high survival and successful adaptation to different rearing technologies, confirming the feasibility of artificial propagation programmes for the conservation and sustainable management of the species. Wild brood fish from the Uidene River were successfully adapted to captive conditions, enabling establishment of broodstock and production of viable offspring under controlled conditions. These findings provide a scientific basis for conservation and restoration measures. Full article

Optimization of holdfast-based asexual propagation is critical for scalable, the genetically uniform seedling production in Sargassum fusiforme aquaculture owing to its capacity to preserve genetic uniformity. Although exogenous auxin can be applied to promote juvenile regeneration, the optimal concentration and associated physiological mechanisms remain insufficiently characterized. In this study, fine strains of S. fusiforme were selected to systematically investigate the concentration-dependent effects and regulatory mechanisms of exogenous indole-3-acetic acid (IAA) on holdfast regeneration. Results revealed that treatment with 2.0 mg·L⁻¹ exogenous IAA significantly enhanced the photosynthetic performance relative to untreated controls. Specifically, this treatment resulted in increased accumulation of chlorophyll a, chlorophyll c, and fucoxanthin as well as elevated maximum relative electron transport rate, maximum quantum yield of PSI, light utilization efficiency, and net photosynthetic rate. Concurrently, nitrogen assimilation and metabolic utilization were markedly stimulated, as evidenced by significant increases in the activities of nitrogen synthesis-related enzymes and substantial accumulation of soluble proteins and total carbohydrates. These coordinated physiological improvements collectively contributed to a 185.4% increase in relative growth rate and 417.1% increase in holdfast regeneration rate as compared with the control group, thereby supplying abundant energy and biosynthetic precursors essential for photosynthesis and juvenile development. Ultimately, the holdfasts exhibited accelerated differentiation into morphologically mature juvenile thalli. Overall, application of 2.0 mg·L⁻¹ exogenous IAA represent a highly effective strategy for enhancing holdfast regeneration efficiency and improving the viable seedling output. This study provides a mechanistic foundation and an expandable solution for addressing the supply of S. fusiforme seedlings. Full article

Red tilapia (Oreochromis sp.) fry are routinely transported between hatcheries and grow out farms, yet the effects of transport duration on epidermal barrier-associated responses and goblet cells remain poorly defined. This study assessed the impact of simulated transport on epidermal morphology, immune-related gene expression and goblet cell density in red tilapia fry. Fish were assigned to four groups (0, 5, 12 and 20 h of transport). Skin samples were analyzed for relative mRNA expression of 10 genes associated with tight junction proteins, mucins, antimicrobial peptides and cytokines using RT-qPCR, and for epidermal goblet cell density by histology. Transport significantly modulated eight genes, forming three co-expression clusters associated with inflammatory, barrier-related, and mucus-related responses, with mainly non-linear time courses. MUC2, DB-4, IL-1β, and TGF-β1b showed transient increases at 5–12 h, whereas MUC5AC and claudin transcripts increased earlier and approached control levels at 20 h. Goblet cell density remained relatively stable up to 12 h but declined after 20 h, coinciding with changes in MUC2 and MUC5AC expression and suggesting altered mucosal responses during prolonged transport. Overall, transport durations ≤ 12 h were associated with relatively stable epidermal responses, whereas 20 h induced pronounced changes in goblet cell density and barrier-associated gene expression. These findings provide information that may assist future optimization of transport practices in tilapia aquaculture. Transport stress in red tilapia fry induces rapid defensive responses, significantly modulating gene expression and mucosal dynamics; this is characterized by increased mucus production, goblet cell density, and early upregulation of mucins (MUC2), followed by later increases in tight junction genes and anti-inflammatory cytokines, alongside a temporary downregulation of antimicrobial peptides. Full article

The digital transformation of shrimp aquaculture in Ecuador has accelerated the adoption of traceability technologies to improve transparency, regulatory compliance, and supply chain coordination. However, persistent structural limitations—such as technological fragmentation, low interoperability, and inconsistent data quality—continue to constrain their effectiveness. This study develops an approach to managing informational uncertainty in traceability systems, grounded in information theory and operationalized through the Technological Management Model for Shrimp Production (TMMT-SP). Methodologically, the research follows an abductive systemic modeling approach, integrating a systematic literature review, structural analysis of the production system, and ontological modeling to identify and classify interdomain gaps. The findings show that informational uncertainty emerges as a structural property of the system, resulting from misalignments across informational, technological, and governance dimensions. These misalignments limit the coherence, reliability, and integration of traceability processes. In response, the study proposes a structural entropy-based framework (understood as an operational representation of systemic informational dispersion) to diagnose, prioritize, and address these gaps, shifting the focus from isolated technological adoption toward systemic coherence. This approach provides a conceptual and methodological basis for designing technology management strategies to reduce uncertainty in complex production systems. Full article

The aquatic pathogen Aeromonas salmonicida SRW-OG1 is responsible for substantial mortality in Epinephelus coioides and many other cultured fish species. This study investigates the contribution of trpE to the pathogenicity of A. salmonicida SRW-OG1 in E. coioides. Specifically, trpE encodes a key enzyme in tryptophan biosynthesis; however, its function in regulating virulence in A. salmonicida remains uncertain. Phenotypic assays indicate that deletion of trpE markedly impaired bacterial growth and significantly reduced multiple virulence-associated traits, including swimming motility, biofilm formation, chemotaxis, hemolytic activity, and extracellular enzyme activity. Transmission electron microscopy revealed that the ΔtrpE mutant lacked flagella, indicating that trpE is involved in flagellar formation or maintenance. In an E. coioides infection model, fish infected with ΔtrpE showed a cumulative survival rate of 48.3%, whereas those infected with the wild-type SRW-OG1 suffered 100% mortality. The ΔtrpE mutant also exhibited reduced bacterial loads in target organs (liver, head kidney, and spleen), while pretreatment with ΔtrpE provided 53.3% protection against a subsequent wild-type challenge. Transcriptomic analysis identified 616 differentially expressed genes, mainly enriched in pathways including flagellar assembly, bacterial chemotaxis, two-component systems, quorum sensing, and biofilm formation. Metabolomic analysis further showed a significant decrease in N-butyryl-L-homoserine lactone, an acyl-homoserine lactone quorum-sensing signal in the ΔtrpE mutant. These findings suggest that trpE contributes to mesophilic A. salmonicida SRW-OG1’s virulence by partially affecting quorum-sensing signal production and motility-related pathways. The attenuated phenotype and protective effect of ΔtrpE indicate its potential as a live attenuated vaccine candidate for controlling A. salmonicida infection in aquaculture. Full article

We reexamined the critical importance of water motion in measuring algal growth and photosynthetic rates, addressing a significant limitation in traditional static incubation approaches. It presents a comprehensive framework for dynamic measurement methods that better simulate natural hydrodynamic conditions experienced by both macroalgae and other benthic autotrophs. We considered the barrier effects of the diffusion boundary layer surrounding the algae on the fluxes of gases and nutrients across the cellular membrane, and integrates findings demonstrating that flow-enhanced mass transfer of nutrients, inorganic carbon and O₂ across diffusion boundary layers can increase photosynthetic performance in macroalgae including the tested Sargassum, Porphyra and Macrocystis species. We provide quantitative comparisons demonstrating that increased velocities of water current can enhance photosynthetic and/or nutrient uptake rates compared to stagnant conditions. The comparative analysis highlights the advantages of flowing water systems in reducing diffusion limitations and better simulating natural environments against the technical simplicity of static methods. We detailed practical methodologies including flow-through system setup and sealed chamber with magnetic stirring techniques for macroalgae, and brush substrate for benthic diatoms. These approaches enable diurnal physiological tracking and reveal saturation responses to increasing water velocities. The methodological framework provides researchers with robust protocols for more accurate assessment of algal photosynthesis and primary productivity in both experimental and applied contexts such as aquaculture, carbon sequestration, and ecological monitoring. Full article

Tenacibaculosis, caused by Tenacibaculum maritimum, remains a major bacterial disease affecting marine aquaculture, particularly European seabass farming. This study evaluated the immune response and protective efficacy of a formalin-inactivated T. maritimum vaccine administered by immersion or intraperitoneal (i.p.) injection in European seabass (Dicentrarchus labrax). Each vaccination strategy was evaluated using its corresponding experimental challenge model 36 days post-vaccination. Vaccine performance was assessed by relative percentage of survival (RPS), expression of selected immune-related genes (IL-1β, IL-10, IgT), and specific serum IgM production. Intraperitoneal vaccination followed by i.p challenge provided significant protection, with 87% survival and an RPS of 67, accompanied by elevated serum IgM levels and pronounced systemic immune activation. Immersion-vaccinated fish also showed complete survival; however, the unexpectedly low mortality in the corresponding mock-vaccinated controls limited the discriminatory capacity of the immersion challenge model and prevented a robust assessment of vaccine efficacy according to the defined criteria. Gene expression analysis revealed distinct immune profiles, with immersion vaccination inducing an early but transient response, whereas i.p. vaccination elicited stronger and more sustained systemic activation, particularly within innate and humoral immune pathways. Principal component analysis further demonstrated clear clustering of immune responses according to vaccination route. These findings demonstrate the potential of an autogenous vaccine to protect European seabass against tenacibaculosis and highlight the importance of considering both vaccination route and the challenge model when interpreting vaccine efficacy. Further studies should optimise immersion vaccination protocols and investigate local mucosal immune responses to support the development of effective vaccination strategies for juvenile European seabass. Full article

Transgenesis and gene editing offer a promising approach for more efficient and sustainable aquaculture by generating high-performance fish to enhance global food security. This article provides a comprehensive review of the history, current status, and future perspectives of employing transgenesis and gene-editing technologies to improve fish production and welfare, focusing on catfishes, which represent a diverse group of economically important fish. We discussed the application of various genetic technologies, including gene transfer (transgenesis) and gene editing, to boost fish economic traits and achieve genetic confinement. We also reviewed the progress on integrating transgenesis and gene-editing techniques for multiple gene editing, an approach that can speed up and make the genetic modification of fish more efficient. This review also highlights several research gaps in the current literature on gene transfer and gene editing in catfishes. Specifically, it provides directions for future catfish research, including the employment of transcriptomics in phenotypic assessment of transgenic and gene-edited fish, addressing compensatory mechanisms when selecting the gene-editing targets, and accounting for gene-environment and gene-nutrition interactions. It also highlights the application of advanced gene-editing tools, integration of genomic selection and artificial intelligence with gene editing, transparent public education about the benefits and risks of genetic biotechnology, and the development of effective reproductive confinement strategies. Full article

The emergence of antibiotic-resistant Vibrio parahaemolyticus poses a challenge to sustainable shrimp aquaculture and highlights the need for effective antibacterial alternatives. In this study, silver nanoparticles were biosynthesized using Eri silk fibroin (ESF) as both a reducing and stabilizing biopolymer. Eri silkworms can be reared on cassava leaves, an abundant agricultural by-product in Thailand, thereby supporting waste valorization and the circular bioeconomy. Optimal synthesis was achieved at an AgNO₃-to-ESF weight ratio of 1:4, 60 °C, and 4 h, yielding 82.8% ESF-AgNPs with a particle size of 10.8 ± 2.3 nm and a polydispersity index of 0.19 ± 0.01. TEM, XRD, and XPS confirmed the formation of well-dispersed metallic Ag⁰. The particles remained colloidally stable for at least four weeks. ESF-AgNPs exhibited minimum inhibitory and bactericidal concentrations of 12.5 and 25 µg/mL, respectively; inhibited biofilm formation by 52.45–99.98%; and increased intracellular reactive oxygen species generation. After 72 h, silver release reached 5.70% in deionized water and 9.30% in TSB containing 3% NaCl. Artemia franciscana survival remained 96.2% after 24 h at the MBC. These findings support ESF as a sustainable platform for producing antibacterial and antibiofilm AgNPs with a preliminary safety margin, although further in vivo efficacy and chronic-toxicity studies are required before practical application. Full article