Latest Issue
- Abstract：Sub-lakes (isolated lakes during low water level) of Poyang Lake play critical roles in maintaining biodiversity, regulating water quality, and supporting food webs. Excess nutrient in these sub-lakes caused eutrophication, and was therefore increasingly concerned. However, the underlying mechanisms of nutrient dynamics remain unclear, especially under extreme weather conditions. We selected a typical sub-lake (Zhanbei Lake) of Poyang Lake as the study area. Its phosphorus and nitrogen dynamics during a typical water year (2021) and an extreme drought year (2022) was examined using a process-based model of the environmental fluid dynamics code (EFDC) model. A factor contribution index (FCI) was calculated based on scenario simulations to identify the drivers and their impacts on nutrient dynamics. Results show that extreme drought intensified the impacts of precipitation on total nitrogen (TN) dynamics, with a contribution increasing from 30.8% in typical water year to 74.4% in extreme drought year. For total phosphorus (TP) dynamics, precipitation had a contribution of 18.8% in typical water year, compared with that of 37.3% in extreme drought year. Other drivers affecting TP dynamics included the initial TP conditions of the sub-lake. This study demonstrated the high potential of process-based models in exploring the cause-effect relationships between nutrient dynamics and extreme drought within this unique sub-lake ecosystem.Keywords：extreme drought;sub-lakes;environmental fluid dynamics code (EFDC) model;nitrogen;phosphorus0|0|0
Updated：2026-05-08 - Abstract：Changes in lake shorelines can significantly impact its ecological environment and lead to the erosion of wetland soils. Accurate extraction and continuous monitoring of lake shorelines are critically important for protecting and managing these ecosystems. To characterize the evolution of Chaohu Lake shoreline from 2000 to 2020, we used Landsat remote sensing imagery in combination with the modified normalized difference water index (MNDWI) and the digital shoreline analysis system (DSAS). The spatiotemporal changes of the shoreline were quantified using the end point rate (EPR) and linear regression rate (LRR) metrics. Results indicate that between 2000 and 2020, the surface area of Chaohu Lake shrank by 2.38 km2 and its shoreline length decreased by 2.89 km, following a pattern of initial expansion followed by contraction. The most rapid shoreline retreat (6.63 km) occurred between 2005 and 2011. There was significant spatial variability in the shoreline change, especially in areas such as Hongshi Bay and Jindou Donglu, where the highest erosion and accretion rates were 22.09 m/a (EPR) and 20.72 m/a (LRR), respectively. Notably, the western part of the lake (near Hefei) experienced greater human disturbance and correspondingly higher annual shoreline change rates (EPR: 0.73 m/a; LRR: 0.91 m/a) than the eastern part (EPR: 0.60 m/a; LRR: 0.47 m/a). Overall, these findings provide a scientific basis for ecological restoration and sustainable shoreline management of Chaohu Lake.Keywords：Chaohu Lake;Landsat imagery;digital shoreline analysis system (DSAS);lake shoreline7|0|0Updated：2026-05-08
- Abstract：The shallow-buried brines in Bankog Co Salt Lake (BCSL) are characterized by high total dissolved solids (TDS) and K, Li, B, Br concentrations, which is apparently different from the lake waters’, indicating great potential of exploitation. The hydrochemistry and formation of these shallow-buried brines are still mysterious. We collected 17 shallow-buried brine samples, and 4 lake brine samples from various locations in BCSL, and conducted elemental and D-O (deuterium, also known as heavy hydrogen and oxygen) isotopic analysis to clarify the solute sources and formation mechanisms of the shallow-buried brines. Results reveal that: (1) the shallow-buried brines are highly mineralized Na-Cl type brines, rich in Na+,
- Abstract：The taxonomic basis of the genus Anthophysa has remained unclear since its establishment in 1822. Only one partial LSU rDNA sequence is available to date, and its taxonomic position in the Chrysophyceae remains largely unknown. We combined morphological characteristics with newly acquired molecular evidence, including the nuclear SSU, ITS, and complete LSU rDNA, and identified two strains of the genus Anthophysa collected from Xizang and Shanghai, China. Distinguishing species within this genus based solely on morphological characteristics was found quite challenging, as the two strains were morphologically extremely similar. The phylogenetic trees constructed based on the LSU single gene and the SSU, ITS, and LSU multiple genes supported the identification of the specimen from Xizang as Anthophysa baimaiquensis sp. nov. and that from Shanghai as A. shanghaiensis sp. nov. Moreover, the taxonomic position of the genus Anthophysa within the class Chrysophyceae and its topological position on the phylogenetic tree were clarified. We identified the origin of Anthophysa through Bayesian relaxed-clock analysis, thereby providing an important temporal basis for reconstructing the evolutionary history of Anthophysa.Keywords：Anthophysa;Chrysophyceae;morphology;phylogenetic;taxonomy8|0|0Updated：2026-05-07
- Abstract：In marine ecosystems, nitrogen cycling is vital for ecological balance, especially in anoxic and micro-aerobic environments like deep-sea sediments. Facultative anaerobes, such as Pseudomonas species, are key players due to their ability to adapt to varying oxygen levels and perform denitrification. Metagenomic analysis showed that Pseudomonas species possess the genomic potential for the most complete denitrification pathways among the taxa studied, emphasizing their ecological importance in deep-sea nitrogen cycling. We isolated denitrifying strains from deep-sea cold seep environments and confirmed their activity using chromogenic assays. Among them, Pseudomonas stutzeri 273, a facultative anaerobic denitrifier, was chosen for further study. Growth experiments showed that while biomass accumulation was delayed in anoxic sealed environments, nitrate reduction occurred actively, indicating energy metabolism is driven by denitrification. Genomic analysis revealed a complete denitrification pathway, and transcriptomic profiling highlighted significant upregulation of denitrification genes under oxygen-limited conditions, particularly during early growth phases. Additionally, genes related to peptidoglycan biosynthesis, flagellar assembly, motility, and flavin adenine dinucleotide (FAD)-dependent redox reactions were upregulated under anoxic conditions, suggesting adaptive responses to energy stress and environmental sensing. These findings enhance our understanding of P. stutzeri 273’s potential role in nitrogen cycling within fluctuating oxygen environments and offer new insights into microbial nitrogen loss in deep-sea habitats.Keywords：deep sea;Pseudomonadota;denitrification;ecological significance6|0|0Updated：2026-05-07
- Abstract：Microbial communities in arid region lakes are highly sensitive to salinity fluctuations, yet systematic comparisons of free-living (FL) and particle-attached (PA) bacteria along salinity gradients remain scarce. This study focuses on five lakes in the northwestern China, where salinity ranges from freshwater to brackish (0.17–13.88). Using 16S rRNA high-throughput sequencing, null model analysis, and co-occurrence network approaches, we investigated the diversity and driving mechanisms of FL and PA bacterial communities. Results show that: (1) PA communities exhibited significantly higher α-diversity than FL communities, with PA diversity decreasing as salinity increased, while FL diversity followed a U-shaped trend; (2) beta-dispersion analysis indicated that the spatial heterogeneity of PA communities was stronger compared to FL communities (P<0.001); (3) redundancy analysis (RDA) showed that salinity was the main factor controlling the differentiation of FL communities (35.5% contribution), while water temperature (WT) was the primary driver of PA community variation (37.0%); (4) assembly mechanism analysis suggested that dispersal limitation (DL) was the dominant process shaping FL community assembly (64.2%), whereas homogeneous selection (HoS) governed PA community assembly (58.8%). This study provided novel insights into the response mechanisms and ecological adaptations of microbial communities in arid region lakes to environmental changes, offering critical theoretical support for aquatic microbial ecology in the context of inland lake salinization under climate change.Keywords：free-living (FL) bacteria;particle-attached (PA) bacteria;salinity;microbial diversity;community assembly mechanism4|0|0Updated：2026-05-07
- Abstract：Interspecific competition drives ecological niche partitioning, biodiversity maintenance, and social structure evolution, yet empirical evidence for its role in rapid evolution remains limited. We examined whether competitive pressures could accelerate life history divergence in two zooplankton species, Ceriodaphnia cornuta and Moina micrura, using an experimental evolution approach. Under controlled competitive conditions, the life-history traits (survival, fecundity, and body size) were tracked in newborns over 10-d intervals across generations. C. cornuta, the dominant competitor in monocultures and mixtures, responded to competition by accelerating neonate maturation, reducing neonate body size, thereby reinforcing its ecological dominance. Conversely, subordinate M. micrura delayed first reproduction and reduced adult body size to conserve resources under competitive stress. Crucially, competition induced rapid life history divergence between the species, with both employing reproductive trade-offs and morphological plasticity. This study provided direct experimental evidence for rapid evolution driven by competition, and elucidated a potential mechanism by which evolutionary processes may maintain ecological equilibrium.Keywords：competitiveness;interaction;life history;experimental selection;rapid evolution;ecological process6|4|0Updated：2026-04-27
- Abstract：Typhoon, as one of the most destructive weather systems, causes significant impacts on the marine environment. We established a multi-dataset case-comparative framework by integrating Argo buoy observations, HYbrid Coordinate Ocean Model (HYCOM) reanalysis data, and Integrated Multi-satellitE Retrievals for GPM (IMERG) satellite precipitation data, to elucidate the upper ocean response mechanisms to four distinctive typhoons in the northwest Pacific (2021–2024). Our analysis revealed several key mechanistic insights. Results show that the HYCOM model can simulate the temperature and salinity trends, but systematically underestimates precipitation dilution (with salinity deviations of 0.1–0.2) and mixing intensity (with temperature deviations of 0.4–1.2 °C), due to insufficient parameterization of the wind-wave-current coupling process. After typhoon passage, sea surface temperature decreases sharply by 1.5–3 °C due mainly to the enhanced vertical mixing, while salinity decreases by 0.1–0.6 as a result of the combined effects of precipitation dilution and mixing with deep high-salinity water. The mixed layer depth (MLD) increases from 40 to 100 m. The temperature recovers gradually within 10 d due to solar shortwave radiation and advection, while salinity recovers more slowly due to its conservative nature. A notable asymmetry was observed, and the Ekman suction driven by strong winds was enhanced on the right side of the typhoon track, leading to a significantly deeper disturbance depth compared to the left side. Significant thermal anomalies were observed in the subsurface (80–500 m), resulting from the competing effects of vertical mixing and Ekman pumping. The cold wake is primarily governed by wind-driven vertical mixing, while its spatial pattern is co-regulated by precipitation-induced freshwater input. Ekman transport plays a critical role in subsurface heat redistribution. These findings underscore the importance of multi-platform observations for understanding complex ocean responses and highlight key areas for improving coupled model parameterizations.Keywords：typhoon;upper ocean;response;Array for Real-time Geostrophic Oceanography (Argo);HYbrid Coordinate Ocean Model (HYCOM)4|2|0Updated：2026-04-27
- Abstract：The metamorphosis of marine invertebrates from pelagic larvae to benthic juveniles is a critical life event characterized by complex morphological alternations and physiological adjustments. The metamorphic transition of the sea cucumber Apostichopus japonicus from an auricularia to a juvenile larva significantly influences individual survival and population dynamics, with vital implications for aquaculture and restoration ecology. However, the underlying mechanisms that regulate larval attachment and metamorphosis in echinoderms remain poorly understood. We analyzed the comprehensive metabolic profiles of A. japonicus across the whole metamorphosis process, including early auricularia stage (A), doliolaria stage (D), one-month juveniles (J1), and four-month juveniles (J4), using an untargeted metabolomics approach based on ultra-performance liquid chromatography coupled with electrospray ionization time-of-flight mass spectrometry (UPLC-ESI-Q-TOF/MS); and identified 2 507 metabolites, of which 880, 747, 1 416, and 1 359 differentially metabolites (DMs) were further examined in comparisons of A versus D, D versus J1, D versus J4, and J1 versus J4. Elevated levels of key metabolites (long-chain fatty acids, phospholipids, eicosanoids and free amino acids) in the D stage showed their essential roles in endogenous energy supply, membrane construction, and metabolic regulation, whereas co-occurring vitamins and pro-apoptotic substances presented roles in cellular protection and homeostasis during metamorphosis. Furthermore, we found two significantly-enriched core KEGG pathways (cysteine and methionine metabolism, purine metabolism). Although the specific roles of these metabolites and pathways in the sea cucumber development are not yet completely known, they provide new metabolic insights into the regulatory mechanisms of echinoderm metamorphosis.Keywords：metamorphosis;Apostichopus japonicus;metabolomics;differential metabolite;echinoderm12|2|0Updated：2026-04-22
- Abstract：Driven by growing environmental awareness, water-saving technologies in aquaculture are receiving increasing attention. To develop a novel water-saving shrimp farming technology, we constructed a biofloc system (BF group) using bagasse as the core material, with a conventional water-exchange system serving as the control (CK group). A 42-d farming experiment of shrimp Penaeus vannamei in production scale was conducted to evaluate the water quality control effect of bagasse biofloc and its effects on the growth performance, body composition, immunity and intestinal flora of P. vannamei. Results indicate that the cumulative water exchange of BF group was 36.92% lower than that of CK group, and the water consumption per kg shrimp production was reduced by 24.03%. The concentration of total ammonia nitrogen (TAN) in BF group was significantly lower than that in CK group, whereas the concentrations of NO2--N and NO3--N were significantly higher than those in CK group (P<0.05). Bagasse bioflocs could be eaten by P. vannamei, which accounted for 23.14% of the contribution rate of food. The final body length, yield and survival rate of P. vannamei in CK group were significantly higher than those in BF group (P<0.05). The contents of crude protein and crude fat of P. vannamei in BF group were significantly higher than those in CK group (P<0.05). The total antioxidant capacity (T-AOC) ability and the activities of catalase (CAT) and alkaline phosphatase (AKP) of P. vannamei in BF group were significantly higher than those in CK group, whereas the nitric oxide synthase (T-NOS) activity was significantly lower than that in CK group (P<0.05). The intestinal microbial community composition and function of P. vannamei in CK group and BF group was similar, but the richness and diversity of BF group were higher (P<0.05). In summary, the use of bagasse bioflocs system for P. vannamei industrial farming significantly reduced the amount of water exchanged. Bagasse bioflocs can be ingested by shrimp and affect the body composition and immunity.Keywords：Penaeus vannamei;industrial farming;bagasse bioflocs;physiological response;intestinal flora3|4|0Updated：2026-04-17
- Abstract：A thorough understanding of the reproductive biology of Portunus trituberculatus, a commercially significant crab species prevalent along the temperate western Pacific coast, is required for sustainable aquaculture. The structure and function of the male mating system of P. trituberculatus were systematically studied using gross morphological examination, scanning electron microscopy, and histological analysis. The mating system consists of paired long first gonopods (G1), short second gonopods (G2), and penises, forming a unique mating complex. G1 is slender and tubular with lateral sutures and a needle-like tip, featuring basal insertion ports for the penis and G2. Histological sections revealed striated muscles, mucous glands, and secretory vesicles within the G1 base, complemented by external pinnate setae on the endopodite. G2 displays a bifurcated terminus with basal striated musculature and surface pinnate setae. Pinnate setae may have sensory functions. The penis is supported by the annular muscle layer and contains spongy connective tissue, and its erection mechanism is driven by haemolymph. During mating, the penis and G2 are inserted into the anterior proximal foramen (AF) and posterior distal foramen (PF), respectively. The results of the gonopod regeneration experiments reveal that the regeneration ability of this species is limited, which may be related to the protected position under the pleon. This study clarified the cooperative working mechanism of the male mating system of P. trituberculatus, providing a theoretical basis for its reproductive physiology research.Keywords：Portunus trituberculatus;mating organ;morphology;histology3|4|0Updated：2026-04-17
- Abstract：The deep-sea environment drives unique genomic adaptations in marine organisms, but comprehensive studies in holothurians are limited. We present the first complete mitochondrial genome of the deep-sea sea cucumber Psychropotes sp. (17 128 bp), containing the typical 37 metazoan genes: 13 protein-coding genes, two ribosomal RNAs, and 22 transfer RNAs. Comparative mitogenomic analysis revealed two notable structural innovations: the presence of three putative control regions and extensive tRNA gene rearrangements. Similar architectures were identified in the congeneric genus Benthodytes, suggesting a possible phylogenetic trend within this family. These structural features may reflect mechanistic adaptations to deep-sea conditions. Additionally, positive selection signals were detected in three respiratory complex genes: ND2 (231 P), ND3 (87 S), and ND4 (352 G), indicating adaptive evolution in key energy metabolism pathways. A negative correlation was observed between mitochondrial guanine-cytosine content (GC content) and depth, which was potentially resulted from deep-sea physiological constraints. This study provides the first mitogenomic characterization of Psychropotes sp. with novel insights into the structural evolution and adaptive mechanisms of mitochondrial genomes in deep-sea holothurians, and established a foundation for further research on metazoan evolution in deep-sea ecosystems.Keywords：mitochondrial genome;deep-sea adaptation;Psychropotes sp.;deep-sea sea cucumber4|3|0Updated：2026-04-17
- Abstract：Climate warming and increased precipitation across the Qinghai-Xizang Plateau (QXP) have caused lake expansion, posing a threat to the safety of local infrastructure and ecosystems. Grain size in lake sediments is a reliable proxy for elucidating hydrological variations in these lakes. However, diverse sources of clastic fractions in lake sediments complicate the interpretation of hydrological changes based on grain-size records. We analyzed 94 surface-sediment samples from Hurleg and Toson lakes, the largest lake system of the Qaidam Basin, northeastern QXP, and explored the grain-size spatial distribution and its hydrological significance. Results demonstrate that fine silt (4–16 μm) is predominant in both lakes, followed by medium to coarse silt (16–63 μm), and clay (<4 μm), while sand (>63 μm) fraction was the least abundant. Using the end-member analysis (EMA), we identified three end-members in Hurleg Lake (HEM1–HEM3) and four in Toson Lake (TEM1–TEM4). In Hurleg Lake, HEM1 and HEM2 mainly come from fluvial deposits from the Bayin River. HEM3 mainly comes from surface runoff and shoreline erosion. In Toson Lake, TEM1 represents typical lacustrine sediments, and TEM2 represents fine-grained terrestrial residual and gully input components. TEM3 originates mainly from aeolian transport and terrestrial residual. TEM4 is a dominant component of the subaqueous alluvial fan. Single-specimen unmixing suggested a differentiation between aeolian inputs and hydrodynamically sensitive components. Fine silt components (mode size 4.0–14.5 μm) are likely related to lake-level variations, whereas coarser silt components (mode size 18.7–51.8 μm) indicate regional dust activity. Notably, in Toson Lake, the fluvial sand components (mode size 66.9–111.5 μm) that were likely derived from western gully runoff, may represent a potential indicator of extreme hydrological events in the Qaidam Basin. These findings provide robust constraints on modern sedimentary processes for reconstructing the history of hydroclimatic changes using grain-size records in the northeastern QXP.Keywords：Hurleg and Toson lakes;grain size;lake surface sediment;hydrology;Qaidam Basin5|23|0Updated：2026-04-09
- Abstract：Triploid induction has been widely used in aquaculture to increase somatic growth, induce reproductive sterility, and mitigate ecological risks from uncontrolled breeding. However, the differences in growth between triploids and diploids are species specific. Grass carp (Ctenopharyngodon idella) is a crucial species in China’s freshwater aquaculture industry. A one-year growth trial was conducted, and the results reveal that triploids exhibited a slower growth rate than diploids did. Further analyses demonstrated that the number of erythrocytes and the size of their nuclei were significantly greater in triploids than in their diploid counterparts (P<0.001), which was accompanied by a reduced packed cell volume (PCV) in triploids (P<0.05). Histological analysis revealed that the triploid liver displayed features of metabolic stress. Liver transcriptome analysis identified 713 differentially expressed genes (DEGs), which showed primarily enrichment in metabolic processes, including hexose, lipid, and monosaccharide metabolism. This analysis also revealed significant downregulation of the growth hormone/insulin-like growth factor (GH/IGF) axis (ghrb, igf1, and igfbp5a) and downstream signaling pathways, namely, PI3K-AKT in triploids. The results of this study characterize the early growth performance of triploid grass carp and provide molecular insights into the growth retardation observed in triploid individuals.Keywords：grass carp;triploidy;growth hormone/insulin-like growth factor (GH/IGF) axis;transcriptome5|10|0Updated：2026-04-07
- Abstract：Qaidam Basin, located in the northeastern Qinghai-Xizang Plateau with high-mountain and deep-valley tectonic setting, is rich in mineral resources of many critical elements of mainly potassium (K), lithium (Li), magnesium (Mg), sodium (Na), uranium (U), and boron (B) leading the nation in these categories. To clarify the distribution and enrichment of potassium and lithium in Qaidam Basin brine, hydrochemical analyses and phase diagrams were carried out on brine water, salt spring water, and inflow river water. Results reveal that paleo-lake water migrated from the northwest to the Triple-lake region in an inverted S-shaped pattern under the control of gravitation. Due to the chemical differentiation, K shows an enrichment trend along the migration path from the northwest to the Triple-lake region, whereas Li is predominantly concentrated in East Taijinar (Dongtai), West Taijinar (Xitai) Lake, and Bieletan mining section in the lower catchments of Nalingele River. The Cl-SO4 type of brines are widely distributed along the migration pathway. However, river water influx has shifted the hydrochemical type of Dongtai and Xitai lakes and Bieletan section into Na-HCO3-SO4 type. Salt spring that distributed along faults contribute a large amount of Ca, K, and Mg elements, thus turn water into Ca-Cl type. Glacial meltwater, after leaching granite and other rock, serves as the primary source of K, and Ca-Cl-typed salt springs are the significant source of both K and Li. These springs have modified the brine chemistry compositions and increased K and Li concentrations in Mahai Lake, Qarhan Salt Lake, and Dalangtan Salt Lake. This systematic analysis of K and Li distribution and enrichment mechanisms provides critical insights for the sustainable exploitation of brine resources in the Qaidam Basin.Keywords：Qaidam Basin;brine;potassium;lithium;salt spring4|11|0Updated：2026-04-07
- Abstract：The advancement of marine fishery constitutes a vital element in the endeavor to build a maritime power and safeguard food security. In light of the strategic requirements of the national marine fishery and marine ranching, In this article, three pivotal aspects are focused on: marine fishery environmental monitoring systems, core monitoring equipment, and key monitoring techniques. A feasibility assessment of the integrated implementation was conducted, probing into the interplay between the development of the marine economy and the marine fishery environment. Notably, the significance of establishing a sound marine fishery environmental monitoring system was underscored. Through in-depth analysis and systematic collation, a comprehensive understanding of the status of demands, industrial policies, technical capabilities, and future trends in the global marine fishery environmental monitoring system was analyzed. In addition, the core challenges and strategic approaches confronting the development of China’s marine fishery environmental monitoring system were clarified. In the near future, by practical development requirements, an ecosystem with monitoring platforms and sensors will be gradually established. Novel organizational models will be explored with key technologies, and major scientific schemes and core tasks in this field will be put forward. In combination with relevant policies regarding fishery environmental monitoring, constructive suggestions for industrial development were provided, and future direction for its progress was outlined.Keywords：fishery environment;marine ranching;monitoring system;monitoring technology;development strategy and recommendations13|4|0Updated：2026-04-07
- Abstract：The satellite synthetic aperture radar (SAR) sensor is one of the most critical tools for monitoring Arctic sea ice. Classifying sea ice types based on SAR images has been a research hotspot. Most existing deep-learning-based sea ice classification models rely on the polarimetric information of SAR images while ignoring the gray-level co-occurrence matrix (GLCM) feature. This study develops a three-branch U-Net model for classifying sea ice in SAR images. By integrating polarimetric information, GLCM features, and auxiliary data, the model can classify open water (OW), young ice (YIC), first-year ice (FYI), and old ice (OIC). The model is trained and tested on the well-known AI4Arctic sea ice challenge dataset. Experiments on 57 testing SAR images demonstrate that the proposed model achieves an overall classification accuracy of 91.45% and an Intersection over Union (IoU) of 0.846 4 for the four-type classification. Ablation experiments were conducted to evaluate the sensitivity of various GLCM features to sea ice classification. The effectiveness of the three-branch input for fusing polarimetric information, GLCM feature, and auxiliary data is validated. Results indicate that incorporating HV_mean significantly enhances classification performance, with an accuracy increase of approximately 0.7% and an improvement in IoU of 0.9%. The three-branch input structure is more effective than the single-branch structure in fusing three types of inputs, resulting in an accuracy increase of 4.7% and an improvement in IoU of 7%. Therefore, the proposed three-branch U-Net model demonstrates stable and reliable capabilities for classifying OW, YIC, FYI, and OIC in SAR images, providing a new approach for Arctic sea ice monitoring.Keywords：synthetic aperture radar (SAR) image;sea ice classification;gray-level co-occurrence matrix (GLCM);U-Net;deep learning8|8|0Updated：2026-04-07
- Abstract：The Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-Cas system is a powerful tool for gene editing, yet it has never been successfully applied to edit genes in dinoflagellates. In CRISPR-Cas-mediated gene editing, magnesium ions (Mg2+) are necessary to maintain catalytic activity. Some studies, however, found that Mg2+ and calcium (Ca2+) ions could modulate flagellar motility and cyst formation of unicellular flagellates, thus affecting their physiology. Here, a single-cell microinjection method was adapted to deliver Mg2+/Ca2+ into cells of the dinoflagellate Alexandrium catenella to test the dose-dependent effects on cyst formation and germination. It was found that Mg2+/Ca2+ treatments
- Abstract：Unmanned aerial vehicle (UAV) datasets can derive diverse features, providing crucial support for fine-scale mangrove species classification. However, achieving high classification accuracy remains challenging due to complex feature interactions. This study utilized multi-source UAV data, including multispectral imagery, light detection and ranging (LiDAR) point clouds, and high-resolution RGB images, from the Gaoqiao Mangrove Nature Reserve, Zhanjiang, Guangdong, South China. Three hybrid feature groups were made by integrating shared multispectral features, vegetation indices, and structural features with texture features derived from principal component analysis (PCA), independent component analysis (ICA), or minimum noise fraction (MNF) dimensionality reduction. An improved Extreme Gradient Boosting (XGBoost) algorithm was developed for dominant feature selection, and random forest (RF) and XGBoost models were built for performance evaluation. The optimal results were obtained using PCA features selected by the improved XGBoost algorithm combined with the XGBoost classifier, achieving an overall accuracy of 98.48% with the user accuracy variance of only 0.000 05 among species. These findings indicate that the modified XGBoost algorithm can enhance classification accuracy and robustness, offering technical support for precise mangrove monitoring, protection, and restoration.Keywords：mangrove fine-scale classification;improved Extreme Gradient Boosting (XGBoost);multi-source unmanned aerial vehicle (UAV) data;feature selection7|2|0Updated：2026-03-30
- Abstract：The phytoplankton light absorption coefficient (aph) is crucial for understanding growth, composition, size classes, photo-acclimation, and carbon cycling processes of phytoplankton. However, the existing estimation methods suffer from low estimation accuracy and limited applicability due to insufficient theoretical support. Sun-induced chlorophyll-a fluorescence (SIF) serves as an optical indicator of phytoplankton photosynthesis activity and holds potential to estimate aph. The factors affecting the relationship between SIF and phytoplankton absorption were explored. A new algorithm for estimating the phytoplankton absorption coefficient at 665 nm (aph (665)) incorporating the diffuse attenuation coefficient of photosynthetically active radiation (Kd (PAR)) was developed to classify water types and SIF and estimate aph (665) for each water type. Validation datasets collected from eight inland waters in China were used to assess the accuracy of the new method. Results demonstrate that the new algorithm outperforms two classical approaches with overall win rate (OWR) of 50.89%, unbiased mean absolute percentage error (UMAPE) of 30.73%, and root mean square error (RMSE) of 0.24/m. Furthermore, the robustness and applicability of the developed algorithm were confirmed through successful application in Belgian inland and coastal waters. Finally, the algorithm was applied to map the spatiotemporal distribution of aph (665) in Taihu Lake for year 2022 using Sentinel-3 Ocean and Land Color Instrument (OLCI) imagery. The advantages of this method can be further expanded with the launch of the Plankton, Clouds, Aerosols, and Ecosystems (PACE) satellite with higher spectral resolution.Keywords：sun-induced chlorophyll-a fluorescence;phytoplankton absorption coefficient;diffuse attenuation coefficient;classification of water types4|3|0Updated：2026-03-26
- 联系电话：+86-532-82898754 Email：jol@qdio.ac.cn
- 技术支持由北京北大方正电子有限公司提供 京ICP备09064830号-19
京公网安备11010802024621 - 本系统建议在Chrome、 IE9+ 以上版本浏览器阅读本站内容，360浏览器请切换至极速模式
- Cookies帮助我们提供服务并提供个性化体验。使用本网站，即表示您同意我们使用Cookies
0