Search Results (502)

The Pearl River Estuary (PRE) is highly vulnerable to alien species invasion due to intense anthropogenic activities in southern China. However, the invasion risk of alien aquatic vertebrates in the PRE remains unclear. In this study, 12 environmental DNA (eDNA) samples were collected from the PRE to reveal the composition and distribution of alien aquatic vertebrates using a vertebrate-universal primer set, and to assess their invasion risks using the Aquatic Species Invasiveness Screening Kit (AS-ISK). We identified a total of nine alien aquatic vertebrate species, including one amphibian (Aquarana catesbeiana) and eight fish species (Coptodon zillii, Oreochromis niloticus, Gambusia affinis, Cirrhinus mrigala, Labeo rohita, Pterygoplichthys pardalis, Ictalurus punctatus, and Neosalanx taihuensis). Notably, six of the nine alien species were detected at eight or more sampling sites, indicating their wide distribution in the PRE. Moreover, all nine alien species were classified as high risk based on AS-ISK, suggesting potential damage to local ecosystems and the aquaculture industry. Our study can help inform policy decisions for the prevention and control of alien aquatic vertebrates in the PRE. Full article

Cascade reservoirs on the Drina River (Bosnia and Herzegovina) are heavily modified water bodies that require reliable biological tools for assessing trophic status and ecological potential. Under the Water Framework Directive (WFD), assessments of surface water ecological status and potential rely on biological quality elements, since aquatic communities integrate and respond to prevailing environmental conditions and thus serve as reliable indicators of water quality. This study aims to (i) describe phytoplankton diversity, biomass, and functional-group composition along the Drina reservoir cascade, (ii) examine monthly changes across the studied reservoirs, (iii) determine trophic status and ecological potential, and (iv) provide a preliminary estimate of total phosphorus thresholds that may support future setting of ecological potential boundaries. Phytoplankton composition and functional groups were analysed in three longitudinally connected reservoirs of the Drina River during four monthly surveys in 2024. A total of 80 phytoplankton taxa were recorded, with diatoms dominating most of the study period. The highest biomasses were recorded for Fragilaria crotonensis, Dinobryon divergens, Acanthoceras zachariasii and Sphaerocystis sp., while the dominant functional groups were P, E, A, and F. Phytoplankton assemblage structure showed moderate spatial differentiation among the reservoirs. Mean chlorophyll a and Carlson’s Trophic State Index indicated eutrophic conditions in the Višegrad Reservoir and mesotrophic conditions in the Perućac and Zvornik reservoirs, while biomass showed a pronounced summer maximum, particularly in Perućac. Ecological potential was generally classified as good or better, except for a moderate classification in the Zvornik Reservoir in late summer. The good/moderate TP boundary was estimated at 39 µg L⁻¹, linking EQR-based ecological assessment with the onset of eutrophic conditions. Overall, this study represents the first application of the phytoplankton functional group approach in cascade reservoirs in Bosnia and Herzegovina and may provide a valuable basis for the development of a phytoplankton-based monitoring framework in lakes and reservoirs, which is currently lacking. Full article

The Qingshankou Formation shales in the southeastern uplift of the Songliao Basin provide an ideal archive for constraining the controls of paleoenvironment on organic matter enrichment. Taking the shale succession at the Niaohexiang section of Binxian as the study object, we combined field sampling with TOC measurements, whole-rock X-ray diffraction, and major, trace, and rare earth element analyses. The strata are dominated by black shale and dark gray mudstone, with mineral assemblages composed mainly of clay, felsic, and carbonate minerals; argillaceous shale exceeds 60%. Normal alkanes display a post-peak distribution with C₂₇ as the dominant peak, low Pr/Ph ratios, and gammacerane index values of 0.18–0.26. Regular steranes are generally V-shaped, whereas some samples show high C₂₉ sterane contents and a reversed L-shaped pattern. Major elements are dominated by SiO₂ and Al₂O₃, trace elements such as Sr and Ba are relatively enriched, and rare earth elements show light REE enrichment with a pronounced negative Eu anomaly. These signatures indicate an upper-crustal felsic provenance and a continental island arc tectonic setting. Organic matter contents are low and derived mainly from terrestrial higher plants with minor aquatic input. Paleoenvironmental reconstruction suggests deposition in a freshwater to slightly brackish, semi-arid, anoxic-reducing shallow lacustrine setting with relatively low productivity, whereas dolostone formed under more saline, arid, and more productive conditions. Climatic fluctuations, salinity variations, and alternating redox states jointly controlled organic matter enrichment, and late-stage lacustrine salinization and anoxia associated with dolostone horizons enhanced organic matter preservation. Full article

Global freshwater resources face severe water quality degradation, with chlorophyll-a (Chl-a) concentration serving as a critical eutrophication indicator. While deep learning methods enable accurate Chl-a retrieval from remote sensing reflectance (Rrs) spectra, the scarcity of paired Rrs-Chl-a samples limits model generalization and causes overfitting, particularly in optically complex inland waters. To address this data bottleneck, we propose a physics-constrained latent diffusion model for synthesizing high-fidelity paired Rrs-Chl-a data to augment limited training sets for deep learning-based water quality retrieval. Our framework integrates three key innovations: (1) a lightweight variational autoencoder achieving 8.6:1 latent space compression, reducing computational overhead while preserving spectral features; (2) band-selective attention mechanisms targeting chlorophyll-sensitive wavelengths (440, 550, 680, and 700–750 nm) based on bio-optical principles; and (3) physics-guided conditional encoding that captures concentration-dependent spectral responses across oligotrophic to eutrophic regimes. Evaluated on the GLORIA dataset, our model demonstrates superior performance in spectral similarity (0.535), sample diversity (0.072), and distribution matching (Fréchet distance 0.0008) compared to conventional generative models. When applied to data augmentation, synthetic spectra improved downstream Chl-a retrieval from R²= 0.75 to 0.91, reducing RMSE by 39%. This physics-informed generative approach addresses data scarcity in aquatic remote sensing research, supporting global needs for enhanced understanding of inland and coastal water quality dynamics in data-limited regions. Full article

This article presents a comprehensive assessment of sediment contamination in the Irtysh River within the industrial zone of the city of Ust-Kamenogorsk, using the Specific Combinatorial Sediment Pollution Index (SCSPI). This study includes a set of priority chemical elements characteristic of the region’s technogenic load (Be, Cu, Zn, As, Se, Cd, Te, Hg, Pb), taking into account their hazard class, persistence in bottom sediments, and ability to accumulate in fine-grained (pelitic) fractions. The assessment was carried out based on the calculation of the frequency index of background exceedance (S_α) and the exceedance multiplicity index (S_β), relative to the effective local background value, followed by the determination of the partial pollution indices (Ki) and the integral SCSPI indicator. It was established that, for most elements, the frequency of exceedance ranges from 75% to 100%, indicating widespread surpassing of the effective local background. The partial indices vary within 4–7 points, with cadmium and zinc making the greatest contribution to the formation of integrated pollution due to the presence of local accumulation zones. Correlation analysis showed that the proportion of the pelitic fraction (<0.01 mm) is most strongly associated with the accumulation of Cd (r = 0.67) and Se (r = 0.66), indicating the preferential accumulation of these elements in fine-grained sediments. Principal component analysis revealed stable geochemical associations among the elements. For the <2.0 mm fraction, the first three principal components explain 73.57% of the total variance, with PC1 mainly associated with Pb, Se, and Cd. For the <0.2 mm fraction, the first three components explain 72.44% of the total variance, and PC1 is characterized by high loadings of Zn, Cd, As, and Se, reflecting the strengthening of the technogenic association in fine-grained material. The SCSPI values across the studied cross-sections range from 5.0 to 5.6, corresponding to a moderately polluted state of bottom sediments (Classes 3a–3b). The spatial distribution of the index reflects the combined influence of technogenic sources and hydrodynamic processes responsible for the redistribution of fine-grained material. The obtained results confirm the applicability of the Specific Combinatorial Sediment Pollution Index (SCSPI) for an integrated assessment of the ecological condition of bottom sediments and for identifying zones of increased technogenic load. A comprehensive approach to the analysis of bottom sediment pollution is proposed, enabling a more accurate identification of spatial distribution patterns of contaminants and their accumulation zones. This provides a scientific basis for the development of adaptive strategies for monitoring and management of aquatic ecosystems. This study is of significant practical importance for advancing sustainable environmental management and the rational use of natural resources under increasing anthropogenic impact. Full article

Monitoring thermal effluent is critical for assessing aquatic ecosystem health, yet traditional satellite remote sensing and in situ point measurements often fail to capture fine-scale thermal dynamics in narrow streams and complex coastal areas due to spatiotemporal resolution limitations. This study establishes a high-precision surface water temperature mapping protocol using a low-cost Unmanned Aerial Vehicle (UAV) equipped with an uncooled thermal infrared sensor (FLIR Vue Pro R) to overcome these observational gaps. We investigated two distinct hydrological environments—an inland stream and a coastal sea—to provide initial evidence for the applicability of an in situ-based linear regression calibration model across contrasting aquatic settings. The initial uncalibrated radiometric temperatures exhibited significant bias errors reaching up to 9.2 °C in the stream and 9.4 °C in the coastal area, primarily driven by atmospheric attenuation and environmental factors. However, the proposed calibration method dramatically reduced these discrepancies, achieving Root Mean Square Errors (RMSE) of 0.43 °C and 0.42 °C, respectively, with high determination coefficients (R² > 0.87). The derived high-resolution thermal maps successfully visualized the detailed diffusion patterns of thermal plumes, revealing a steep temperature gradient of approximately 13 °C in the stream discharge zone and a distinct 5 °C elevation in the coastal effluent area relative to the ambient water. These findings demonstrate that UAV-based thermal remote sensing, when coupled with a rigorous radiometric calibration strategy, can serve as a cost-effective and reliable tool for environmental monitoring, bridging the critical scale gap between local point measurements and regional satellite observations. Full article

Microplastics represent an emerging threat to aquatic ecosystems, human health, and coastal aesthetics, with increasing concern about their accumulation on beaches due to ocean currents, wave action, and accidental spills. Despite their environmental impact, current methods for detecting and quantifying microplastics remain largely manual, time-consuming, and spatially limited. In this study, we propose a deep learning-based approach for the semantic segmentation of microplastics on sandy beaches, enabling pixel-level localization of small particles under real-world conditions. Twelve segmentation models were evaluated, including U-Net and its variants (Attention U-Net, ResUNet), as well as state-of-the-art architectures such as LinkNet, PAN, PSPNet, and YOLOv11 with segmentation heads. Models were trained and tested on augmented data patches, and their performance was assessed using Intersection over Union (IoU) and Dice coefficient metrics. LinkNet achieved the best performance with a Dice coefficient of 80% and an IoU of 72.6% on the test set, showing superior capability in segmenting microplastics even in the presence of visual clutter such as debris or sand variation. Qualitative results support the quantitative findings, highlighting the robustness of the model in complex scenes. Full article

This work presents a portable polarimetric multispectral imaging (PMSI) system operating in the visible to shortwave infrared range (VNIR–SWIR: 400–1700 nm) and its application to target detection, discrimination from aquatic backgrounds, and polymer identification. The instrument integrates two synchronized cameras with motorized bandpass filters and piezoelectric polarization control, enabling the acquisition of 48 wavelength–polarization measurements per capture. This configuration allows the extraction of both intensity-based and polarimetric features, including the degree of linear polarization (DoLP). A complete radiometric and polarimetric calibration framework is implemented, encompassing system response characterization, polarization-dependent gain correction, and reflectance normalization under variable illumination. Experiments conducted on a representative set of 16 polymer materials show that polarimetric information consistently improves class separability compared to intensity-only features, with a mean gain of 6.9 (95% CI: 6.35–8.47). Although the correlation between intensity- and DoLP-based separability is moderate (r = 0.44), the results indicate complementary identification capability. Material recoverability was further evaluated using spectral unmixing techniques (VCA, N-FINDR, and PPI), with VCA offering the best accuracy–complexity trade-off on the calibrated Stokes reflectance dataset. Despite these gains, identification among chemically similar polyethylene variants remains challenging due to limited spectral and polarimetric contrast. An underwater detectability study under natural illumination reveals strong wavelength-dependent constraints: SWIR penetration is limited to 4 cm, whereas VNIR bands (430–550 nm) preserve detectability up to 20 cm, with DoLP enhancing edge visibility. These results motivate future validation in more complex aquatic conditions and with increased spectral dimensionality. Full article

The use of animals in biomedical research and university teaching remains socially sensitive, shaped by ethical concerns, regulations, and public expectations. While animal models are still essential for basic and translational research, society increasingly demands transparency, strong welfare protections, and the development of alternative methods. This study investigated Spanish university students’ attitudes toward the use of animals in basic research, translational research, and educational settings, and examined their acceptance of different species for addressing human health problems. It also assessed how sociodemographic variables, personality traits, empathy, and anthropomorphism relate to these views. The sample included 653 students, predominantly women, heterosexual, and urban residents. Most participants supported the use of animals in research, whereas opinions regarding teaching uses were more divided. Attitudes toward the use of laboratory animals consistently differed by gender and field of study, with men and students in science-related disciplines showing higher acceptance. Of the psychological variables assessed, only anthropomorphism showed moderate negative correlations with support for the use of laboratory animals across all contexts. Species strongly influenced attitudes: companion animals generated the most opposition, primates and livestock elicited mixed responses, and rodents, invertebrates, and aquatic species received the highest support. Overall, students generally accept animal use but vary substantially by species, gender, and academic background. Full article

Background/Objectives: Severe acquired brain injury (sABI) disrupts early rehabilitation because arousal fluctuates, trunk control is fragile, and agitation limits therapy tolerance; land-based practice is frequently constrained by fall risk and staffing. We aim to reframe aquatic therapy as a programmable multisensory environment to stabilize arousal and support axial alignment before conventional impairment targets are feasible. Here, programmable denotes the deliberate titration and reporting of water depth, turbulence or perturbation, temperature, body orientation, and flotation and manual support as intervention inputs. Methods: This perspective integrates principles from neurobehavioral assessment, motor control, and immersion physiology to propose the Arousal–Alignment–Action loop as a falsifiable model and to define manipulable aquatic inputs (water depth, turbulence or perturbation, temperature, body orientation, and flotation and manual support) as dosing parameters. We outline a pragmatic testing ladder (within-session micro-experiments, feasibility studies, and embedded evaluations) and a minimal outcomes and confounder set to support cumulative evidence. Results: The framework links state regulation to alignment and goal-directed behavior, specifies predictions that can fail, and highlights boundary conditions (sedation, autonomic instability, pain, recent surgery or wounds, and cervical or cardiopulmonary constraints). A minimal outcome package spanning arousal/responsiveness, trunk control, behavioral dysregulation, participation/tolerance, and basic physiology is proposed, with optional objective adjuncts for mechanism-oriented studies. Conclusions: Treating water as a measurable and titratable medium, rather than a generic modality, may reduce early intensity bottlenecks and improve implementability and comparability of aquatic neurorehabilitation research in medically stable sABI; however, the model is intended as hypothesis-generating until supported by stronger direct clinical evidence. Full article

To address the issues of operational complexity, long duration association, and reliance on specialized equipment with existing detection methods for Vibrio parahaemolyticus, this study established a rapid detection method for V. parahaemolyticus in exported aquatic products based on the domestically developed Enzymatic Recombinase Amplification (ERA) technology. To target the thermolabile hemolysin gene (tlh) and the iron-regulated virulence regulatory protein gene (irgB) of V. parahaemolyticus, highly specific ERA primers and probes were designed and screened. Two detection platforms, a colorimetric method and a fluorescent method, were developed. Method validation results showed that this detection system achieved specific amplification for all 30 tested V. parahaemolyticus strains, with no cross-reactivity observed with 30 other common foodborne pathogenic bacteria. The detection sensitivity for both the fluorescent and colorimetric methods reached 10⁻¹ ng/μL, with a minimum detection limit of 10 CFU/25 g for artificially contaminated samples. The entire detection process, including sample preparation, requires only approximately 20 min—significantly faster than traditional culture (24–72 h) or even conventional PCR methods. Collaborative validation across five independent laboratories confirmed excellent reproducibility, with inter-laboratory agreement yielding a Kappa coefficient of 0.98. The ERA method operates at a low, constant temperature (37–39 °C), eliminating the need for thermal cyclers. When combined with portable isothermal amplification devices and visual (colorimetric) readout, it offers a distinct advantage in terms of speed, cost-effectiveness, and suitability for resource-limited or field settings compared to existing PCR-based or culture-based platforms. This method is simple to operate, rapid, sensitive, and highly suitable for on-site application, providing a reliable and practical technical solution for the rapid screening and risk monitoring of V. parahaemolyticus in exported aquatic products. Full article

Sports performance in aquatic environments is governed by biomechanical, physiological, neuromuscular and perceptual–mental constraints that differ fundamentally from those encountered on land. As a result, athletes with comparable general physiological or motor capacities may achieve markedly different performance outcomes in aquatic sports. Within functional kinesiology and sport science, aquatic performance is still frequently interpreted through isolated physiological, biomechanical, or technical variables, which limits both explanatory depth and applied relevance. This Perspective article introduces aquaticity as an integrated latent construct representing a multidimensional determinant of sports performance specific to the aquatic environment. Aquaticity is conceptualized as a functional framework that modulates how general physiological and motor capacities are expressed under aquatic constraints, integrating key domains of exercise physiology, sport biomechanics, neuromuscular control, energetic regulation, and perceptual–mental stability. The relative contribution of these domains is considered discipline-specific and dependent on task and environmental demands. Breath-hold diving is presented as a particularly suitable model for examining aquaticity, as apnea and hypoxic–hypercapnic stress amplify interactions between physiological regulation, neuromuscular control, and biomechanical efficiency. Training and diagnostic tasks performed in real aquatic settings are interpreted as manifest indicators of aquaticity, enabling ecologically valid athlete monitoring and performance assessment. Within this framework, energetic aquaticity is highlighted as a central functional sub-construct linking metabolic regulation, movement efficiency, and neural control during performance under respiratory constraints. The proposed conceptual framework has important implications for functional kinesiology, sport biomechanics, exercise physiology, and applied athlete monitoring in aquatic sports. Aquaticity is advanced not merely as a descriptive concept, but as a unifying framework that can guide future experimental research, discipline-specific diagnostics, individualized training design, and safety-oriented performance assessment in aquatic environments. Full article

The geochemical characteristics of major elements in lake sediments provide insights into aquatic environmental variations, the regional geological background, and the intensity of weathering processes. This study investigates Dongping Lake (DL) using 20 surface sediment samples, analyzing nine major elements. Spatial interpolation was used to characterize their distribution patterns, while principal component analysis, self-organizing maps, and absolute factor analysis–multiple linear regression methods were applied to identify element sources and interpret their geological significance using weathering indicators. Results show that surface sediments are dominated by SiO₂ (46.49%), Al₂O₃ (13.10%), and CaO (11.25%). Controlled by hydrodynamic conditions, major elements are mainly concentrated in the southern part of the lake near the inflows of the Dawen and Liuchang Rivers, with concentrations decreasing from south to north. Riverine transport is the primary source of major elements, with the Dawen River contributing the most followed by the Liuchang and Yellow rivers. Weathering indicators suggest that source rocks have experienced moderate chemical weathering, reflecting initial sedimentation in a tectonically active setting under warm and humid conditions and relatively short transport distances. These findings provide a geochemical basis for understanding sedimentary processes and environmental evolution in the Dongping Lake basin and offer valuable support for regional water resource management, ecological restoration, and sustainable watershed governance. Full article

Freshwater macrophytes shape not only the morphological “architecture” of shallow-water ecosystems but also their chemical milieu via low-molecular-weight organic compounds (LMWOCs) that may regulate phytoplankton, periphyton, and the microbiome within the leaf/shoot diffusive boundary layer and the surrounding water column. In this study, GC–MS (gas chromatography–mass spectrometry) was used to identify major LMWOCs of the low-molecular-weight metabolome (LMWM) in 11 widely distributed macrophyte species (Myriophyllum spicatum L., Sparganium emersum Rehm., Sparganium gramineum Georgi, the hybrid Sparganium × foliosum A. A. Bobrov, Volkova, Mochalova et Chemeris, Persicaria amphibia (L.) Delarbre, Potamogeton perfoliatus L., Nuphar lutea (L.) Sibth. & Sm., Potamogeton pectinatus L., Potamogeton natans L., Lobelia dortmanna L., and Ceratophyllum demersum L.). Compounds contributing more than 1% to the total LMWOCs pool were considered major, increasing the ecological realism of interpretations by focusing on metabolites more likely to reach effective concentrations in the plant microenvironment. For interspecific comparisons, the maximum recorded values of relative abundance and concentrations were used to estimate species “potential”. In total, 137 major LMWOCs were detected (four remained unidentified), and their numbers varied markedly among taxa (from 11 in N. lutea to 71 in P. perfoliatus). Similarity analyses (Jaccard, Sørensen–Czekanowski, Morisita–Horn) indicated that similarity based on compound lists and similarity based on dominance structure may diverge, reflecting differences between the “LMWOCs set” and the quantitative architecture of LMWOCs within the LMWM. Fatty acids formed the core of the major fraction in all species: they were among the top three compounds in all 11 macrophytes and ranked first or second in 10 of 11, highlighting the lipid module as a universal “structure–signaling–defense/allelopathy” hub in aquatic plants. Also, an analysis of the ecological-biochemical role of the main major LMWOCs in the studied aquatic macrophytes is presented. Overall, the data offer a comparable, ecologically oriented framework for interpreting chemical regulation of communities in macrophyte-dominated habitats and for selecting target compounds/species for subsequent bioassay and field studies. Full article

Carbapenem-resistant Enterobacter cloacae Complex (CRECC) has emerged as an important multidrug-resistant pathogen in healthcare settings, although it has historically received less attention than carbapenem-resistant Klebsiella pneumoniae and other major carbapenem-resistant Enterobacterales (CRE). Recent epidemiological reports from several regions indicate increasing detection rates of CRECC in tertiary hospitals, where it is associated with bloodstream infections, pneumonia, urinary tract infections, and prolonged hospitalization. The dissemination of carbapenemase genes, particularly bla_NDM, bla_KPC, and bla_OXA-48-like, carried predominantly on conjugative plasmids (e.g., IncFII, IncX3, IncL), represents the primary resistance mechanism, often accompanied by porin loss and efflux pump overexpression. High-risk clones such as ST171 and ST78 contribute to nosocomial persistence and outbreak potential. Beyond clinical settings, CRECC and related resistance determinants have been reported in companion animals, livestock, food products, wastewater systems, and natural aquatic environments. Although most available studies examine these sectors separately, the recurring detection of genetically related resistance genes and plasmid types suggests potential epidemiological links that warrant integrated surveillance. Environmental reservoirs, particularly hospital effluents and wastewater treatment systems, may facilitate the maintenance and dissemination of resistance genes. This review synthesizes current evidence on the epidemiology, resistance mechanisms, and evolutionary dynamics of CRECC in human, animal, and environmental contexts under a One Health framework. A better understanding of its ecological distribution and genetic plasticity is essential to inform coordinated surveillance strategies and mitigate the public health risks associated with the continued spread of carbapenem resistance. Full article