Search Results (617)

Rapid urbanization has significantly affected urban ecological environments, necessitating accurate and scientific quality assessments. In this study, we develop an enhanced remote sensing ecological index (WRSEI) for water network cities using Linyi City, China, as a case study. Key innovations include (1) introducing a water–vegetation index to better represent aquatic ecosystems; (2) incorporating nighttime light data to quantify the intensity of human activity; and (3) employing hierarchical PCA to rationally weight ecological endowment and stress indicators. The model’s effectiveness was rigorously validated using independent land use data. The results show that (1) the WRSEI accurately captures Linyi’s “water–city symbiosis” pattern, increasing the assessed ecological quality of water bodies by 15.78% compared to the conventional RSEI; (2) hierarchical PCA provides more ecologically reasonable indicator weights; and (3) from 2000 to 2020, ecological quality exhibited a pattern of “central degradation and peripheral improvement”, driven by urban expansion. This study establishes a validated technical framework for ecological assessment in water-rich cities, offering a scientific basis for sustainable urban management. Full article

Background/Objectives: Replacing fish oil with vegetable oil is an important measure for aquaculture to relieve the pressure of fish oil, but it is also easy to cause the growth decline and metabolic disorder of farmed animals, mainly due to the change in dietary fatty acids. This study investigated the regulatory effects of dietary fatty acid composition on glucose metabolism in large yellow croaker (Larimichthys crocea) with an initial weight of 30.51 ± 0.16 g. Methods: Three isonitrogenous (~43% crude protein) and isolipid (~11% crude lipid) diets were formulated as follows: control (CON, DHA/EPA-rich oil as primary lipid), moderate palmitic acid (MPA, 50% of DHA+EPA-rich oil was replaced by glyceryl palmitate), and high palmitic acid (HPA, 100% of DHA+EPA-rich oil was replaced by glyceryl palmitate). Results: After 10 weeks of feeding, the HPA significantly reduced the liver/muscle glycogen contents, increased the liver lipid content, decreased the serum leptin/insulin level, and increased the adiponectin level. The levels of DHA and EPA in liver were decreased significantly. Transcriptionally, HPA upregulated hepatic glucokinase (gk, glycolysis) but down-regulated glycogen synthase (gys) and insulin/irs2 (insulin pathway) while inhibiting muscle ampk and leptin receptor (lepr). Conclusions: This study showed that high dietary PA/(DHA + EPA) impacted glycolipid homeostasis through endocrine and transcriptional regulation, leading to increased crude lipid and decreased glycogen levels, which provides a theoretical basis for scientific aquatic feed fatty acid formulation. Full article

The study aimed to evaluate bottom sediments as a promising source of probiotic bacteria for aquaculture applications. Bacillus strains were selected as the most suitable bacterial species for application in the food industry. Initially, seven Bacillus spp. strains were isolated from the intestinal contents of healthy sterlet specimens; however, none of them demonstrated high potential probiotic properties. Subsequently, bottom sediments were considered as a source of probiotic strains. In the bottom sediments, bacilli exist in a vegetative form and constitute an integral part of the microbial community. A total of 120 Bacillus spp. strains were isolated and comprehensively analyzed. Proteolytic and amylolytic activities were detected at moderate levels in almost all isolated strains. Most isolates exhibited low or negligible antioxidant, DNA-protective, and antimicrobial activities; however, a small group of strains showed high values of these properties. Principal component and cluster analyses indicated the co-existence of three life strategies of bacilli in bottom sediments. These findings highlight the high probiotic potential of bacilli from bottom sediments and support their suitability as novel probiotics for enhancing the health and productivity of aquatic organisms in aquaculture. Full article

Duckweed (Spirodela polyrhiza), a fast-growing aquatic plant rich in protein and bioactive compounds, offers a sustainable alternative to conventional aquafeed protein sources. This study evaluated the effects of incorporating 25–75% duckweed meal into a commercial feed on grass carp (Ctenopharyngodon idella) over a 6-week trial. Fish meal, wheat starch, and vegetable oil was added in amounts to obtain isonitrogenous and isoenergetic diets. Additionally, another grass carps were used for extended feeding until they reached approximately 1000 g, using the feed with the optimal duckweed inclusion rate (25%). Fish fed a diet consisting of 75% commercial feed and 25% duckweed meal (F75D25) exhibited significantly higher weight gain. Muscle analysis revealed increased protein content (up 15%, p < 0.05) and improved amino acid and fatty acid profiles. Liver, muscle, and blood assays showed elevated antioxidant enzyme activities (SOD up 20%, LYS up 18%; p < 0.05) and immune markers (CRP, GOT; p < 0.05), indicating enhanced health status. Transcriptomic and metagenomic analyses confirmed the upregulation of immune-related genes (e.g., SOD1, IL-6; fold change > 2, p < 0.01) and beneficial shifts in gut microbiota (e.g., increased Firmicutes). These findings highlight duckweed’s potential as a nutrient-rich, health-promoting ingredient for sustainable aquaculture diets. Full article

Chloro-organophosphate ester (Cl-OPE) accumulation in soil and aquatic environments, and their potential hazard to crops, has attracted widespread attention. However, little is known about the potential adverse effects of Cl-OPEs on plants. Green onions are a specialty vegetable worldwide, and the heavy application of pesticides during their growth period has led to increasingly severe soil contamination in cultivation areas. We evaluated the toxic effects of Cl-OPEs on green onions and examined their toxicity mechanism. After 20 days of treatment, physiological parameters were measured across five biological replicates per treatment. Results indicated that as Cl-OPE concentrations increased, green onion leaf malondialdehyde (MDA) content and reactive oxygen species (ROS) levels rose significantly. Concurrently, the activities of the antioxidant enzymes superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) were significantly enhanced. However, leaf chlorophyll content and net photosynthetic rate (Pn) decreased significantly, indicating that Cl-OPE-induced oxidative stress inhibited photosynthesis. Meanwhile, the nutrient content of green onions gradually decreased as the concentration of Cl-OPEs increased. In conclusion, Cl-OPEs can damage chloroplasts by promoting ROS accumulation, which results in the yellowing of green onion leaves. The resulting decrease in Pn reduced the plant’s ability to assimilate nutrients. Full article

Turions (overwintering buds) as modified shoot apices constitute specialized vegetative structures that enable many aquatic vascular plants to withstand adverse environmental conditions such as low temperature, desiccation, or limited light availability. Turions serve as major storage sites for organic reserves, including sugars, proteins, fatty acids, and polyamines. Owing to their high content of energy-rich and nutritionally valuable compounds, turions represent a potential renewable resource for applications in biofuel production, animal feed, and the food industry. We investigated whether arabinogalactan proteins (AGPs) occur in aquatic plant turions and localized these compounds within specific tissues or cell types. This work was designed to evaluate whether stress-resistant storage organs may constitute a practical reservoir of AGPs. Considering the central role of AGPs in plant responses to abiotic stress, we hypothesized that turions, which routinely encounter cold, anoxia, and intermittent dehydration, would exhibit particularly high AGP accumulation. Mature turions of aquatic species (Aldrovanda vesiculosa, Utricularia australis, U. intermedia, and Caldesia parnassifolia) were used. Immunofluorescent labeling with AGP-specific antibodies (JIM8, JIM13, JIM14, LM2, MAC207) and confocal laser scanning microscopy were employed. In Aldrovanda vesiculosa and Caldesia parnassifolia, AGP epitopes were abundantly presented in cytoplasmic compartments. AGP epitopes occurred in secretory structures in turions of all examined species (trichomes of Aldrovanda and Utricularia, secretory ducts of Caldesia). In analyzing turions of four different species, we identified Aldrovanda vesiculosa turions as the most promising potential source of AGPs, also noting their high reserve potential for use in animal feed or the food industry. Full article

Accurate shoreline determination is essential for the study of coastal and inland water processes, hydrography, and the monitoring of aquatic and terrestrial environments. This study compares two modern remote sensing technologies: MLS conducted with a USV and photogrammetry using a UAV. The research was carried out on Lake Kłodno, characterised by a complex shoreline with vegetation and hydrotechnical structures. Both approaches satisfied the accuracy requirements of the IHO Special Order for shoreline extraction (≤5 m at the 95% confidence level). For the UAV-derived orthophoto, the error within which 95% of shoreline points were located (corresponding to 2.45·σ) was 0.05 m for the natural shoreline and 0.06 m for the variant including piers, both well below the IHO threshold. MLS achieved a 95% error of 1.16 m, which also complies with the Special Order criteria. UAV data enable clear interpretation of the land–water boundary, whereas MLS provides complete three-dimensional spatial information, independent of lighting conditions, and allows surveys of vegetated or inaccessible areas. The results demonstrate the complementarity of the two approaches: UAV is well suited to highly accurate shoreline mapping and the identification of hydrotechnical structures, while MLS is valuable for analysing the nearshore zone and for surveying vegetated or inaccessible areas. The findings confirm the value of integrating these approaches and highlight the need to extend research to other types of waterbodies, to consider seasonal variability, and to develop methods for the automatic extraction of shorelines. Full article

Understanding and monitoring benthic habitat distribution is essential for implementing ecosystem-based fisheries management (EBFM). Satellite remote sensing offers a rapid and cost-effective approach to marine habitat assessments; however, its application requires context-specific adjustment to account for environmental variability and differing study aims. As such, predictor variables must be tailored to the specific site and target habitat. This study uses Sentinel-2 Level 2A surface reflectance satellite imagery and stability selection via Random Forest Recursive Feature Elimination to assess the importance of remote sensing indices for mapping moderately deep (<20 m) seagrass habitats in relation to the Marine Stewardship Council-certified Western Australia Enhanced Greenlip Abalone Fishery (WAEGAF). Of the seven indices tested, the Normalised Difference Aquatic Vegetation Index (NDAVI) and Depth Invariant Index for the blue and green bands were selected in the optimal model on every run. The kernelised NDAVI and Water-Adjusted Vegetation Index also scored highly (both 0.92) and were included in the final classification and regression models. Both models performed well and predicted a similar cover and distribution of seagrass within the fishery compared to the surrounding area, providing a baseline and supporting EBFM of the WAEGAF within the surrounding marine protected area. Importantly, the use of indices from freely accessible ready-to-use satellite products via Google Earth Engine workflows and expedited ground truth image annotation using highly accurate (0.96) automatic image annotation provides a rapidly repeatable method for delivering ecosystem information for this fishery. Full article

Water pollution caused by petroleum-derived volatile organic compounds such as benzene, toluene, ethylbenzene, and xylenes (BTEX), as well as methyl tert-butyl ether (MTBE), poses a growing threat to aquatic ecosystems and human health. These contaminants, together with the organic matter and nutrients present in municipal wastewater, highlight the need for sustainable treatment technologies adapted to tropical conditions. This study evaluated the removal efficiency of BTEX, MTBE, and conventional pollutants using hybrid constructed wetlands (HCWs) that combine vertical subsurface flow (VSSF-CW) and horizontal subsurface flow (HSSF-CW) systems. Two plant species—Heliconia latispatha and Phragmites australis—were tested, along with a polyculture and an unvegetated control. The hybrid systems treated synthetic influents formulated to simulate contaminated municipal wastewater. Parameters including COD, TSS, N–NH₄⁺, N–NO₃⁻, P–PO₄³⁻, BTEX, and MTBE were monitored and analyzed using ANOVA and Tukey’s test (p < 0.05). Vegetated systems achieved COD removal efficiencies exceeding 85%, compared with 72% in the control. Phragmites australis obtained the highest removal of suspended solids (92 ± 3%) and ammonium nitrogen (88 ± 2%), whereas Heliconia latispatha exhibited superior phosphorus removal (84 ± 4%). The polyculture displayed a synergistic effect, achieving removal rates of 93% for benzene, 91% for toluene, and 88% for MTBE, with statistically significant differences relative to the control (p < 0.05). In conclusion, hybrid constructed wetlands planted with Heliconia latispatha and Phragmites australis demonstrated high efficiency and stability in removing BTEX, MTBE, and conventional pollutants under tropical conditions, positioning themselves as a sustainable, low-cost, and esthetically valuable treatment alternative. Full article

Watercress is a nutrient-dense, aquatic leafy vegetable with significant public health and economic potential. Hydroponically cultivated watercress can offer greater nutritional benefits due to the controlled delivery of specific nutrients. From an agronomist’s perspective, watercress has the advantage of optimized environmental resource efficiency, achieved through reduced energy, chemical, and water consumption, as well as its short cultivation cycle. Glucosinolates (GSLs) in watercress enhance sustainable agriculture by naturally protecting crops from pests and diseases, reducing the need for chemical inputs. They also increase market value and shelf-life, supporting resource-efficient and profitable farming. Within the pharmaceutical space, GSLs are well-known for their chemo preventive and anti-inflammatory properties. This review aims to summarize research findings, critically evaluate existing studies to highlight current knowledge, and identify research gaps, and to guide future investigations. The synthesis of the reviewed literature demonstrates that increased sulphate generally improves GSL content. However, not many studies have looked specifically at how magnesium sulphate (MgSO₄) affects watercress. This review highlights the specific impact of MgSO₄ on GSL production in watercress, which could provide valuable insights for optimizing nutrient management in hydroponic systems and enhancing the health benefits of this nutrient-dense crop. Full article

The Yangtze River Basin, one of China’s most vital watersheds, sustains both ecological balance and human livelihoods through its extensive lake systems. However, since the 1980s, these lakes have experienced significant ecological degradation, particularly in terms of aquatic vegetation decline. To acquire reliable aquatic vegetation data during the peak growing season (July–September), when clear-sky conditions are scarce, we employed Chinese domestic satellite imagery—Gaofen-1/6 (GF-1/6) Wide Field of View (WFV) and Huanjing-2A/B (HJ-2A/B) Charge-Coupled Device (CCD)—with approximately one-day revisit frequency after constellation networking, 16 m spatial resolution, and excellent spectral consistency, in combination with deep learning algorithms, to monitor aquatic vegetation across the basin. Comparative experiments identified the near-infrared, red, and green bands as the most informative input features, with an optimal input size of 256 × 256. Through visual interpretation and dataset augmentation, we generated a total of 5016 labeled image pairs of this size. The U-Net++ model, equipped with an EfficientNet-B5 backbone, achieved robust performance with an mIoU of 90.16% and an mPA of 95.27% on the validation dataset. On independent test data, the model reached an mIoU of 79.10% and an mPA of 86.42%. Field-based assessment yielded an overall accuracy (OA) of 75.25%, confirming the reliability of the model. As a case study, the proposed model was applied to satellite imagery of Lake Taihu captured during the peak growing season of aquatic vegetation (July–September) from 2020 to 2025. Overall, this study introduces an automated classification approach for aquatic vegetation using 16 m resolution Chinese domestic satellite imagery and deep learning, providing a reliable framework for large-scale monitoring of aquatic vegetation across lakes in the Yangtze River Basin during their peak growth period. Full article

Temporary wetlands are ecosystems formed by seasonal or intermittent inundation that provide habitats and support hydrological and biogeochemical processes. Despite their importance, they are often overlooked due to their small size and ephemeral nature. The lava forest of Jeju Island, known as Gotjawal, is a rare ecosystem where temporary wetlands occur despite the high permeability of basaltic terrain. This study reports an assessment of temporary wetlands in the Seonheul Gotjawal forest, focusing on identification, boundary delineation, and key characteristics. Wetlands were identified using four years (2020–2023) of water level monitoring and vegetation surveys. Hydrological boundaries were defined by maximum observed water levels, and ecological boundaries were delineated from plant distribution. Ecological boundaries consistently fell within hydrological ones, showing the value of vegetation indicators in wetland identification. Wetland areas ranged from 347–1214 m², with average depths of 0.2–0.9 m and hydroperiods of 13–76%. Water levels correlated with total rainfall. Three geomorphological wetland types were distinguished, with the shortest hydroperiods observed in small lava depressions functioning as forest microhabitats for endemic species. This study provides the first integrated evaluation of temporary wetlands in the Gotjawal lava forest and offers baseline data for classification and conservation. Full article

Against the backdrop of global climate change, alterations in precipitation regimes—including the increasing frequency of extreme events—have become more widespread, exerting profound impacts on terrestrial ecosystems and reshaping greenhouse gas (GHG) emission dynamics in wetlands. Wetlands, as unique ecosystems formed at the interface of terrestrial and aquatic environments, play a critical role in regulating carbon source–sink functions. In this study, we conducted in situ field simulation experiments to examine how precipitation changes influence the seasonal fluxes of carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O) in the Wayan Mountain headwater wetlands, and further explored the regulatory effects of vegetation attributes and soil physicochemical properties on these fluxes. The results revealed that a moderate increase in precipitation (+25%) enhanced CO₂ emissions and vegetation growth while suppressing CH₄ and N₂O fluxes, indicating a positive ecosystem response to additional water supply. In contrast, extreme precipitation changes (+75% and −75%) weakened the coupling between GHG fluxes and soil factors, resulting in reduced CO₂ flux, amplified variability in CH₄ and N₂O emissions, and inhibited vegetation growth and community diversity. The dominant controls differed among gases: CO₂ was primarily regulated by soil carbon pools, CH₄ was highly sensitive to water availability, and N₂O was influenced by soil nitrogen, pH, and salinity. Overall, moderate increases in precipitation enhance the carbon sink capacity and community stability of alpine wetlands, whereas extreme hydrological fluctuations undermine ecosystem functioning. These findings provide important insights into carbon cycling processes and regulatory mechanisms of alpine wetlands under future climate change scenarios. Full article

Using Shanghai as a case study, this paper develops a multi-source fusion and interpretable machine learning framework. Sentiment indices were extracted from Weibo check-ins with ERNIE 3.0, street-view elements were identified using Mask2Former, and urban indicators like the Normalized Difference Vegetation Index, floor area ratio, and road network density were integrated. The coupling between residents’ sentiments and streetscape features during heatwaves was analyzed with Extreme Gradient Boosting, SHapley Additive exPlanations, and GeoSHAPLEY. Results show that (1) the average sentiment index is 0.583, indicating a generally positive tendency, with sentiments clustered spatially, and negative patches in central areas, while positive sentiments are concentrated in waterfronts and green zones. (2) SHapley Additive exPlanations analysis identifies NDVI (0.024), visual entropy (0.022), FAR (0.021), road network density (0.020), and aquatic rate (0.020) as key factors. Partial dependence results show that NDVI enhances sentiment at low-to-medium ranges but declines at higher levels; aquatic rate improves sentiment at 0.08–0.10; openness above 0.32 improves sentiment; and both visual entropy and color complexity show a U-shaped relationship. (3) GeoSHAPLEY shows pronounced spatial heterogeneity: waterfronts and the southwestern corridor have positive effects from water–green resources; high FAR and paved surfaces in the urban area exert negative influences; and orderly interfaces in the vitality corridor generate positive impacts. Overall, moderate greenery, visible water, openness, medium-density road networks, and orderly visual patterns mitigate negative sentiments during heatwaves, while excessive density and hard surfaces intensify stress. Based on these findings, this study proposes strategies: reducing density and impervious surfaces in the urban area, enhancing greenery and quality in waterfront and peripheral areas, and optimizing urban–rural interfaces. These insights support heat-adaptive and sustainable street design and spatial governance. Full article

Thisreview provides a comprehensive synthesis of recent theoretical and experimental advances on turbulent plane jets interacting with surface waves or rigid vegetation. In wave-affected conditions, a unified mathematical framework based on velocity decomposition and the integral balances of momentum and energy reveals the fundamental scaling laws governing jet spreading and momentum exchange. The analysis demonstrates that wave-induced shear alters classical entrainment mechanisms, leading to modified power-law relationships for jet width and centerline velocity, consistent with laboratory and numerical evidence. In obstructed environments, such as canopies of rigid or flexible vegetation, distributed drag induces a transition from entrainment to detrainment. The resulting momentum loss is captured analytically by incorporating drag-induced dissipation into the Reynolds-averaged momentum equations, yielding exponential decay of jet momentum and reduced mixing efficiency. Together, these models elucidate how environmental forcing—dynamic (waves) and structural (vegetation)—controls the evolution of turbulent jets in natural and engineered aquatic systems. The review highlights key scaling relationships, theoretical developments, and experimental findings, offering a coherent basis for future studies on mixing, dispersion, and transport in complex coastal and vegetated flows. Full article