- CHENG Yongcun;XU Qing;
Motivated by the wide applications of empirical global ocean tide models in Earth science, particularly in shallow waters and coastal regions, we proposed an updated global ocean tide model representing all major diurnal and semidiurnal tidal constituents.We integrated the development technique of the Technical University of Denmark(DTU10) model and calculated the residual tides using the intermediary FES2012 model. We utilized all available Topex/Poseidon, Jason-1, Ocean Surface Topography Mission(OSTM)/Jason-2 primary and tandem missions to develop the new model. To reduce the discrepancies between the model and in situ measurements estimated S2 tide constituent, the ERA-Interim model was selected for dry tropospheric correction of altimetry data.The newly developed model with an improved spatial resolution from 1/8°×1/8° to 1/16°×1/16° was assessed and compared against contemporary global ocean tide models using in situ measurements in coastal regions, continental shelf waters, marginal seas, and deep waters. The results demonstrate improvements in shallow waters and coastal regions, particularly in representative coastal regions such as the Northwest European Shelf and East Asian Marginal Seas. Moreover, the model performs well in simulating S2 and K2 tides with root mean square differences of 0.355 and 0.234 cm, respectively, against in situ measurements in deep waters worldwide. Compared with that of DTU10, the root sum square of the new model for the eight main tidal constituents decrease by 8.4% to0.997 cm.
2025年05期 v.24 1147-1156页 [查看摘要][在线阅读][下载 1158K] - YU Peiyi;QIAN Shengyi;HU Haibo;HE Shengping;XIONG Yijie;FU Tianxiang;WANG Yu;
East Asia is a region characterized by a typical monsoon climate, which is accompanied by strong precipitation with complex spatiotemporal variability during summer. Previous works have emphasized the impact of tropical signals on extreme summer precipitation over East Asia, but the roles of the mid-high latitude cyclones are still unclear. Using a reanalysis dataset, this study discloses the synergistic influences of anomalous signals from different latitudes on the extreme precipitation event in the BeijingTianjin-Hebei(BTH) region during the summer of 2023. The main conclusions are obtained as follows: the decreased sea ice density caused more Arctic cyclones to generate at positions further west in the Barents Sea and the west of the Kara Sea and then move southeast to East Asia in 2023. Furthermore, the synergistic influences of the outward Arctic cyclones and anomalous signals from middle and low latitudes are discussed. First, the significant northward jump of the Western Pacific Subtropical High(WPSH) provided the favorable condition of large-scale background circulation for summer precipitation in the BTH region in 2023. In addition, the southward intrusion of the Arctic cyclones and the mid-latitude zonal wave trains transported massive cold air to the BTH region.Subsequently, the cold air masses met with the warm moist air carried by the landfall typhoon ‘Doksuri', which generated strong fronts and triggered the extreme precipitation on July 29. However, another severe typhoon, ‘Kanu', generated and moved northward from the tropical Pacific, which caused the further northward shift of the WPSH and the termination of this persistent extreme precipitation on August 1.
2025年05期 v.24 1157-1168页 [查看摘要][在线阅读][下载 9288K] - HU Yuyi;SHAO Weizeng;MARINO Armando;JIANG Xingwei;WANG Zhenyuan;
The purpose of this study is to analyze the impact of upper ocean dynamics on velocity bunching, represented by azimuthal cutoff wavelength(i.e., sea surface wind, wave, and current). In this study, over 1400 dual-polarized(vertical-vertical(VV)and vertical-horizontal(VH)) Sentinel-1(S-1) synthetic aperture radar(SAR) images collected in tropical cyclones(TC) are utilized.These images are combined with wind and rain observations from the stepped-frequency microwave radiometer(SFMR), wave simulations conducted using a third-generation numerical wave model, WAVEWATCH-III(WW3), and SAR-derived wind information collected from CyclObs winds. The WW3-simulated significant wave height(SWH) is validated against measurements from HY-2B altimeter taken in August and September 2021, yielding a root mean square error(RMSE) of 0.48 m and a correlation coefficient(COR) of 0.88. The SAR-based azimuthal cutoff wavelengths in VV polarization, which quantitatively represent the effect of velocity bunching, are compared with theoretical values calculated using WW3-simulated SWH. A notable relationship is observed between the difference in azimuthal cutoff wavelength and SAR-derived wind speed and WW3-simulated SWH. Analysis results show that the correlation between SAR-based azimuthal cutoff wavelength and SWH is stronger than that with wind and current. Finally, a machine learning algorithm is used to develop an algorithm aimed at simulating the azimuthal cutoff wavelength in TCs, including wind, wave, and incidence angle. This method yields an RMSE of 8.90 m, a COR of 0.91, and a scatter index of 0.04 for VV-polarization SAR.
2025年05期 v.24 1169-1181页 [查看摘要][在线阅读][下载 1651K] - CHEN Yanyu;ZHAO Xin;GU Weifang;BAO Xianwen;LIU Zhen;CHEN Bo;SHI Maochong;
This study used moderate-resolution imaging spectroradiometer(MODIS) data and a high-resolution unstructured grid finite volume community ocean model(FVCOM) to investigate the seasonal and regional characteristics of physical and ecological elements in the Beibu Gulf. The findings reveal that, in the Beibu Gulf, strong temperature gradients exist in winter, with sea surface temperatures becoming uniform at around 30 °C in summer. Sea surface salinity is influenced by low-salinity water from the Qiongzhou Strait and rivers, as well as high-salinity water from the open sea, reaching its minimum levels in autumn. Chlorophyll-a(Chl-a) concentrations peak in nearshore areas, particularly in autumn. In the Beibu Gulf, a significantly negative partial correlation exists between sea surface temperature and Chl-a(ρ=-0.5). Furthermore, wind patterns exert a considerable influence on different regions outside the eastern Beibu Gulf(|ρ|≥0.49), particularly showing a negative correlation along the Vietnamese coast. Cooling-induced water instability, coupled with wind-driven upwelling, enhances vertical water movement, thus facilitating the upward transport of nutrients. High Chl-a concentrations in the estuarine area are attributed to the nutrient-rich discharges(ρ=0.55) and the strong estuarine gravity circulation induced by intense density gradients. There are also notably high Chl-a concentrations in the eastern Beibu Gulf and the western coast of Hainan Island despite the presence of adverse environmental conditions. These anomalies can be attributed to wind-induced upwelling and tidal mixing front-induced upwelling, respectively. This study presents a comprehensive analysis of the distribution and mechanisms of Chl-a in the Beibu Gulf, thus highlighting the complex interactions among various factors and emphasizing the importance of local environmental conditions.
2025年05期 v.24 1182-1194页 [查看摘要][在线阅读][下载 17829K] - LI Meina;CHEN Bin;LI Haibo;ZOU Liang;CAO Ke;YUE Baojing;HU Rui;LI Xue;
Seagrass beds are crucial coastal ecosystems, functioning as vital blue carbon sinks and natural ecological barriers. However, these ecosystems are increasingly threatened by global climate events, coastal development, and water eutrophication, making them some of the most endangered ecosystems worldwide. In the Yellow Sea and Bohai Sea regions, seagrass bed assessment and monitoring have been largely overlooked. Thus, strengthening research efforts is necessary to identify current distribution patterns and long-term changes in seagrass bed resources. This study focused on a seagrass bed in Sanggou Bay, Rongcheng, using remote sensing(RS) and geographic information system technologies to analyze multisource satellite data from the US Landsat and Chinese resource satellite series. By combining RS indexes with historical survey data, large-scale temporal and geographic distribution data for seagrass beds were obtained in the study area from 1985 to 2022. The spatial distribution and evolution trends of the seagrass bed were analyzed using a water depth inversion model, and the factors driving its degradation were identified. Results indicated that the seagrass bed area in Sanggou Bay fluctuated between 100 and 140 km~2 from 1985 to 2010. During 2010–2013, dynamic changes in the seagrass bed area increased, with a considerable decrease in its overall size. After 2014, changes were minimal, indicating a notably stable state. Seagrass bed degradation in Sanggou Bay is influenced by high-intensity human activities, pollution from coastal land sources, raft cultures, underwater terrain conditions, and sedimentary environmental factors. The findings offer essential insights for developing seagrass restoration and protection strategies in Sanggou Bay and contribute to the broader scientific efforts for coastal ecosystem conservation and rehabilitation.store seagrass beds through initiatives such as the Beautiful Bay construction scheme. A total of 33 ha of seagrass beds have been currently established, with over 29 million seagrass plants thriving within these areas. Investigating the spatiotemporal evolution trend of seagrass beds in Sanggou Bay is crucial for understanding land-sea interaction dynamics. This study employed RS and geographic information system technologies to analyze RS images from the US Landsat satellite and Chinese resource satellite series, enabling an assessment of the spatial distribution characteristics and evolution trends of these vital ecosystems. Furthermore, the study explored the factors contributing to the degradation of these seagrass beds.The findings offer a scientific foundation for ecological environment protection and the sustainable utilization of coastal zone resources.
2025年05期 v.24 1195-1205页 [查看摘要][在线阅读][下载 1610K] - YIN Zegao;LI Feifan;ZHANG Chao;LI Guoqing;
To propel the application of a bottom-hinged flap breakwater in real sea conditions, a two-dimensional computational fluid dynamics numerical model was conducted to investigate the pitching motion response and wave attenuation in random waves.First, the flow velocity distribution characteristic of the pitching flap at typical times was summarized. Then, the effects of random wave and flap parameters on the flap's significant pitching angle amplitude θ_s and hydrodynamic coefficients were investigated. The results reveal that θ_s and wave reflection coefficient K_r values increase with increasing significant wave height H_s, random wave steepness λ_s, and flap relative height. As H_s and λ_s increase, the wave transmission coefficient K_t increases while the wave dissipation coefficient K_d decreases. Additionally, K_t decreases with increasing flap relative height. With increasing equivalent damping coefficient ratio, θ_s and K_t decrease, while K_r and K_d increase. The relationships between λ_s and flap relative height on the one hand and θ_s,K_r, K_t, and K_d in random waves on the other hand are compared to those in regular waves. Based on the equal incident wave energy and the equal incident wave energy flux, the pitching flap performs better in the wave attenuation capability under random waves than in regular waves. Finally, the dimensionless parameters with respect to random wave and flap were used to derive the K_r and K_t formulae, which were validated with the related data.
2025年05期 v.24 1206-1222页 [查看摘要][在线阅读][下载 1579K] - LIU Zhen;CHENG Yongzhou;FANG Mingbao;ZHOU Wenzhe;
The complex topography of natural bedrock shorelines on islands necessitates detailed model testing to thoroughly investigate wave overtopping mechanisms and their variation patterns. This understanding is vital for optimizing the elevation of coastal structures to meet the design requirements for wave overtopping and to ensure safety and efficacy. This paper investigates a nuclear power plant project on an island in Zhejiang Province, China. This study employs small-scale overall model tests and large-scale local model tests to examine the complex dynamics of wave interaction with the island's shoreline. It analyzes the influences of wave parameters, shoreline geometry, and underwater topography on wave overtopping behavior. Comparisons between physical model results and empirical formulae reveal substantial discrepancies in overtopping rates across different model scales. The results stress the remarkable effect of accurate underwater topography representation on wave overtopping predictions and emphasize the need for precise topographic modeling. The results also show that overtopping discharges for complex terrains deviate considerably from values determined using traditional empirical formulas for breakwater overtopping. This outcome indicates that conventional methods may insufficiently address the complexities of natural coastal features. To guarantee reliable predictions of overtopping volumes at specific elevations along complex coastlines, this study advocates employing physical modeling across numerous scales while accounting for detailed terrain and hydrodynamic characteristics.
2025年05期 v.24 1223-1230页 [查看摘要][在线阅读][下载 517K] - LIU Peng;LIU Ziyang;FENG Guodong;CHEN Changlong;
Unmanned surface vehicles(USVs) play a crucial role in various fields, including ocean climate change monitoring, marine resource exploitation, and ecological environment exploration. Out of the many types of USVs, unmanned sailboats have gained considerable attention for their ability to conduct green, large-scale ocean observations. Building on this concept, this paper proposes an unmanned sailboat propelled by parallel dual-wing sails, which is designed to meet the demands of extensive and three-dimensional marine comprehensive observation and data collection. With a focus on the parallel dual-wing sails, this study particularly investigates the effects of variations in the airfoil's angle of attack and the impact of the spacing ratio between the dual sails on propulsion performance. It further analyzes the influence of one sail's angle of attack on the performance of the other sail, as well as the flow field between the two sails. For the air navigation and underwater states, the force characteristics of the dual sail under different inflow velocities were investigated. The research findings indicate that, under certain conditions, the thrust coefficient exhibits a trend of first increasing, then decreasing, and finally increasing again with alterations in the angle of attack α. Different single-sail angles of attack have varying impacts on the opposite sail and the flow field between the dual sails. Moreover, the generated forces are positively correlated with inflow velocity in the air navigation and underwater states. The findings reveal that it is possible to reduce drag,mitigate the adverse effects of sail interaction, and thereby enhance the propulsion performance and overall navigational stability of the sailboat by applying an optimal spacing ratio design and adjusting the angle of attack and inflow velocity.
2025年05期 v.24 1231-1244页 [查看摘要][在线阅读][下载 1669K] - YANG Xiurong;JIANG Annan;WANG Dong;
The mechanical properties of bedding rock in cold regions are frequently affected by freeze-thaw(F-T) cycles and anisotropy. Research on the mechanical characteristics of rock damage under the combined action of F-T and bedding angles is limited,and most traditional rock damage models cannot accurately capture these characteristics. We performed axial compression tests to explore the strength characteristics of bedding slates at the bedding angles of β=0°, 30°, 45°, 60°, and 90° under various F-T cycles. The experimental findings suggest that the elastic modulus and uniaxial compressive strength of the slate declined exponentially as the number of F-T cycles increased. Axial compressive strength was characterized by a U-shaped tendency with the bedding angle. This study proposes a damage model for the uniaxial compressive strength of transversely isotropic rock, which integrates the F-T effect,utilizing the enhanced anisotropic Hoek-Brown strength criterion and a statistical damage model. This model was validated using experimental data. This statistical damage model can precisely capture the dual attributes of rock mass strength reduction with F-T cycles and variations arising from the loading direction.
2025年05期 v.24 1245-1255页 [查看摘要][在线阅读][下载 956K] - HE Jiaru;DENG Zengan;
Sea-surface wind is a vital meteorological element in marine activities and climate research.This study proposed the spectral attention enhanced multidimensional feature fusion convolutional long short-term memory (LSTM) network (SAMFF-ConvLSTM),a novel approach for sea-surface wind-speed prediction that emphasizes the temporal characteristics of data samples.The model incorporates the Fourier transform to extract time-and frequency-domain features from wave and wind variables.For the 12 h prediction,the SAMFF-ConvLSTM achieved a correlation coefficient of 0.960 and a root mean square error (RMSE) of 1.350 m/s,implying a high prediction accuracy.For the 24 h prediction,the RMSE of the SAMFF-ConvLSTM was reduced by 38.11%,14.26%,and 13.36% compared with those of the convolutional neural network,gated recurrent units,and convolutional LSTM (ConvLSTM),respectively.These results confirm the superior reliability and accuracy of the SAMFF-ConvLSTM over traditional models in theoretical and practical applications.
2025年05期 v.24 1256-1268页 [查看摘要][在线阅读][下载 1417K] - AZIMI Hamed;SHIRI Hodjat;
The Arctic region is experiencing accelerated sea ice melt and increased iceberg detachment from glaciers due to climate change. These drifting icebergs present a risk and engineering challenge for subsea installations traversing shallow waters, where iceberg keels may reach the seabed, potentially damaging subsea structures. Consequently, costly and time-intensive iceberg management operations, such as towing and rerouting, are undertaken to safeguard subsea and offshore infrastructure. This study, therefore,explores the application of extra tree regression(ETR) as a robust solution for estimating iceberg draft, particularly in the preliminary phases of decision-making for iceberg management projects. Nine ETR models were developed using parameters influencing iceberg draft. Subsequent analyses identified the most effective models and significant input variables. Uncertainty analysis revealed that the superior ETR model tended to overestimate iceberg drafts; however, it achieved the highest precision, correlation, and simplicity in estimation. Comparison with decision tree regression, random forest regression, and empirical methods confirmed the superior performance of ETR in predicting iceberg drafts.
2025年05期 v.24 1269-1288页 [查看摘要][在线阅读][下载 1069K] - WANG Shengyu;LIU Jinqing;SONG Hongying;FENG Xiaokun;YIN Ping;DUAN Xiaoyong;CAO Ke;
We investigated the concentrations, vertical distribution, and enrichment status of ten trace metal elements(Cr, Hg, Cu,Pb, Zn, Cd, As, Co, V, and Ni) in sediments of core D04 from the muddy area outside the Oujiang River Estuary. In addition to V,As, and Hg, the concentrations of Cr, Cu, Zn, Pb, Cd, Ni and Co were constrained by sediment grain size and organic matter. Although the concentrations of trace metals fluctuated during the 5.8–2.5 kyr BP period, overall variations remained relatively stable.However, during the 2.5–0 kyr BP period, the concentrations of Cd, Zn, Cu, Pb, Ni, Ni, and Cr showed an increasing trend within the fluctuations, ultimately reaching relatively high levels. The muddy area was lightly contaminated by heavy metals such as As, Hg,and Cu. The concentrations of Hg, As, and Cu have been continuously increasing since 2.5 kyr BP, indicating clear impacts from frequent human activities.
2025年05期 v.24 1289-1301页 [查看摘要][在线阅读][下载 1111K] - WANG Jinhuan;HAN Qingbang;GE Kao;SUN Liujia;
Given the challenges of underwater garbage detection, including insufficient lighting, low visibility, high noise levels,and high misclassification rates, this paper proposes a model named CSC-YOLO. CSC-YOLO for detecting garbage in complex underwater environments characterized by murky water and strong hydrodynamic conditions. The model incorporates the Content-Guided Attention(CGA) attention mechanism into the SPPF module of the YOLOv8 backbone network to enhance dehazing, reduce noise interference, and fuse multi-scale feature information. Additionally, a Single-Head Self-Attention(SHSA) mechanism is introduced in the final layer of the backbone network to achieve local and global feature fusion in a lightweight manner, improving the accuracy of garbage detection. In the detection head, the CBAM attention mechanism is added to further enhance feature representation, increase the model's target localization, and improve robustness against complex backgrounds and noise. Furthermore, the anchor box coordinates from CSC-YOLO are fed into Mobile＿SAM to achieve precise segmentation of underwater garbage. Experimental results show that CSC-YOLO achieves a Precision of 0.962, Recall of 0.898, F1-score of 0.929, and mAP_(0.5) of 0.960 on the ICRA19 trash dataset,representing improvements of 2.9%, 1.7%, 2.3%, and 2.0% over YOLOv8n, respectively. The combination of CSC-YOLO and Mobile＿SAM not only enables garbage detection in complex underwater environments but also achieves segmentation. This approach generates additional garbage segmentation masks without manual annotations, facilitating rapid expansion of labeled underwater garbage datasets for training. As an emerging model for intelligent underwater garbage detection, the proposed method holds significant potential for practical applications and academic research, offering an effective solution to the challenges of intelligent garbage detection in complex underwater environments.
2025年05期 v.24 1301-1314页 [查看摘要][在线阅读][下载 785K] - YUE Mengchen;ZHAO Yangguo;LIU Jiannan;ZHANG Yanchao;PAN Chao;
Abstract Mariculture tailwater typically contains a certain concentration of antibiotics;however,conventional biological treatment methods struggle to effectively remove these antibiotics.Therefore,in this study,we modified the carbon felt (CF) anode in sediment microbial fuel cells (SMFCs) to enhance tetracycline (TC) removal in mariculture systems.We fabricated a novel composit material by integrating instant freeze-drying technology with the solvothermal reaction method to combine graphene oxide (GO) and nanoscale SiO_2.Subsequently,the composite material was incorporated into CF for anodic modification,resulting in improved perfor mance of SMFCs in TC removal and electricity generation.The maximum power density achieved was 63.72 mW/m2,nearly 2.9 times higher than that of the unmodified anode.Modified SMFCs exhibited a twofold increase in the degradation rate of tetracycline compared to natural degradation alone and showed significant improvements compared to both the control group and conditions with only GO addition.Furthermore,the modified anode effectively enriched populations of Leisingera,Oceanimonas,and Halomonas thereby significantly enhancing the electrochemical performance of the SMFCs.This study successfully demonstrates the application of a modified-anode SMFC using a composite material consisting of GO and SiO2 for on-site removal of TC from mariculture environments.
2025年05期 v.24 1315-1326页 [查看摘要][在线阅读][下载 854K] - CAI Fengjing;WANG Yue;TIAN Zhuangcai;LI Xi'an;XU Jing;MO Yuming;ZHANG Shaotong;WU Jinran;
The increasing frequency of offshore engineering activities,particularly the expansion of offshore oil transport and the rise in the number of oil platforms,has greatly increased the potential risk of marine oil spill incidents.Historically,several large oil spills have had long-term adverse effects on marine ecosystems and economic development,highlighting the importance of accurately delineating and monitoring oil spill areas.In this study,graph neural network technology is introduced to implement semantic segmentation of SAR images,and two graph neural network models based on Graph-FCN and Graph-DeepLabV3+with the introduction of an attention mechanism are constructed and evaluated to improve the accuracy and efficiency of oil spill detection.By comparing the Swin-Unet model,the Graph-DeepLabV3+model performs better in complex scenarios,especially in edge detail recognition.This not only provides strong technical support for marine oil spill monitoring but also provides an effective solution to deal with the potential risks brought by the increase of marine engineering activities,which is of great practical significance as it helps to safeguard the health and sustainable development of marine ecosystems and reduce the economic losses.
2025年05期 v.24 1327-1352页 [查看摘要][在线阅读][下载 4648K]
- SONG Liming;ZHU Mingshan;ZHOU Zihan;LI Yuwei;
To better understand the biological structure of bigeye tuna(Thunnus obesus), albacore tuna(Thunnus alalunga), and longtail tuna(Thunnus tonggol), computed tomography(CT) was used to scan their bodies, and the data are processed by Mimics software. The skeleton, swim bladder, and muscle of the three tuna species are reconstructed in three dimensions. The surface area and volume of the corresponding parts are measured. The results show that the surface areas of the skeleton of longtail tuna, bigeye tuna, albacore tuna accounted for 28.18%, 37.34%, 33.45% of their whole body surface areas respectively; the surface areas of swim bladder accounted for 0, 2.06%, 2.72% of their whole body surface area respectively; and the surface areas of muscle accounted for71.82%, 60.6%, 63.83% of their whole body surface areas respectively. And the volumes of skeleton accounted for 28.18%, 8.05%,3.84%, the volumes of swim bladder accounted for 0, 3.44%, 0.92%, and the volumes of muscle accounted for 94.84%, 88.51%,95.24% of their body volumes respectively. The swim bladder of the longtail tuna has degenerated, while that of the bigeye tuna is conical, exhibiting the highest volume proportion among the three species. In contrast, the swim bladder of the albacore tuna is both flat and elongated, resembling an arc. Additionally, the surface area and the volume of the bigeye tuna's swim bladder differ significantly from those of the albacore tuna. Regarding skeletal and muscular structures, the bigeye tuna has the highest skeletal volume proportion(8.05%), whereas the albacore tuna exhibits the highest muscle volume proportion(95.24%). These morphological differences are closely associated with their respective habitats. This study demonstrates the potential of CT technology in fish morphological research, providing a reliable, non-invasive method for analyzing internal structures, quantifying organ characteristics and improving the accuracy of acoustic stock assessment.
2025年05期 v.24 1341-1350页 [查看摘要][在线阅读][下载 636K] - FANG Jiafeng;LI Qi;
Inbreeding usually reduces the mean phenotypic value of various traits. In Crassostrea gigas, inbreeding depression at the early life stage might be particularly remarkable because of a high mutational load that is difficult to purge. In this study, the effects of inbreeding on the survival rate and gene expression at the early life stage were investigated. Two inbred groups containing five F1 families and five F2 families with a theoretically higher degree of inbreeding were constructed based on an inbred strain.Meanwhile, 5 families were established as the control group(CF) based on the wild population. The results showed that the survival rate of the CF group was significantly higher than those of the two inbred groups. Differential gene analysis showed 1616 common differentially expressed genes(DEGs) in the two inbred groups, which were significantly enriched in pathways associated with immune response, nutrient restriction, and virus infection. By weighted gene co-expression network analysis(WGCNA), 19 common DEGs were enriched in M21, the functional module most closely related to inbreeding, and 6 of them were related to immunity. Notably, the survival rate of F2 was higher than that of F1. A total of 643 DEGs between F1 and CF were screened out, which did not show differential expression between F2 and CF, and these genes were significantly enriched in pathways associated with protein synthesis. These results contribute to a more comprehensive understanding of the genetic mechanism behind the effect of inbreeding on the early survival rate of oyster larvae.
2025年05期 v.24 1351-2013页 [查看摘要][在线阅读][下载 2460K] - LIU Min;WANG Hao;TANG Hengtai;LIU Binghua;WEN Haishen;HE Feng;
Circular RNAs(circRNAs) are a type of endogenous competitive RNA that can perform various functions and regulate a number of biological activities in organisms. Many studies have shown that circRNAs can modulate skeletal muscle development in animals. However, the effects of circRNAs on the skeletal muscle development of Japanese flounder and its regulatory mechanisms remain unclear. We screened circRNA＿2111 from previously obtained transcriptomic data related to Japanese flounder skeletal muscle development. Derived from the tefb gene, it has been designated as circtefb. Circtefb was formed by the reverse splicing of two exons of tefb. Circtefb was more stable than its corresponding linear RNA. There was a significant difference in the expression of circtefb at different stages P1(90 d), P2(12 months) and P3(24 months) of Japanese flounder(p<0.05). Over-expression of circtefb in Japanese flounder myocytes resulted in a significant upregulation of proliferation marker genes ccnd1, ccnd2a and pcna(p<0.05),suggesting that it promoted proliferation of Japanese flounder myocytes. The expressions of ccnd1, ccnd2a, and pcna were significantly decreased after the transfection of pol-miR-138 into Japanese flounder myocytes(p<0.05). In addition, circtefb can suppress pol-miR-138 function by binding to it, which was detected by dual-Luciferase reporter assay and co-transfection of circtefb and polmiR-138, thereby promoting the proliferation of Japanese flounder myocytes. The results indicated the function of circRNAs in Japanese flounder muscle development,, which is also helpful to understand the growth and development of other fish species.
2025年05期 v.24 1364-1374页 [查看摘要][在线阅读][下载 730K] - XU Zhenqi;LIU Yang;WANG Jintao;
Biological data in fishery ecology have complex structures and are highly heterogeneous. Catch per unit effort(CPUE)estimated from fishery-dependent data are often used to characterize abundance indices(AI) of fish species, which is critical in fish stock assessment. However, additional considerations need to be undertaken to ensure robust estimation because of the latently complicated structures in fishery-dependent data. Here, we elaborated the process of constructing multi-output artificial neural network models to standardize CPUE for heterogeneous fishing operations and applied it to the skipjack tuna(Katsuwonus pelamis) in the western and central Pacific Ocean(WCPO). Seasonal, spatial, and environmental factors were input variables, and the CPUE of four types of skipjack tuna fisheries were set as output variables. The optimal structure for multi-output neural network was evaluated by systematic comparison in 100 runs hold-out cross-validation. The results showed that the final multi-output neural network model with high accuracy can predict the spatial and temporal trends of skipjack tuna abundance.
2025年05期 v.24 1373-1395页 [查看摘要][在线阅读][下载 2537K] - FU Zhenqiang;CHEN Qinglong;YE Yinjun;ZHAO Huixin;LIN Genmei;LU Jianguo;
The relationship between microbial communities and their hosts is important to the health and productivity of marine animals in aquaculture.This study investigated the microbiomes in the gut and gill of Penaeus vannamei using 16S rRNA gene sequencing,comparing the microbial characteristics in the fast-growing trait and in the control group.Fast-growing individuals exhibited significantly different growth parameters and gut/gill microbiomes.Significantly higher weight gain and condition factors,as well as lower hepatosomatic indices (HSI),were observed in fast-growing individuals.Fast-growing individuals also displayed significantly higher operational taxonomic unit (OTU) counts (in gills) and greater phylogenetic diversity (PD) in both gut and gill microbiomes,while Lactobacillus was significantly more abundant and showed strong network centrality in the gut of this group.Furthermore,beta diversity analysis revealed significant differences in microbial community structure between the groups in both gut and gills.Functional predictions indicated increased activity in metabolic pathways (e.g.,carbon metabolism,protein export) in the fast-growing group,reflecting the adaptations to increased energy utilization.Conversely,other genera such as TM7a were found at significantly lower abundance in the fast-growing group and showed significant correlations with growth parameters,highlighting potential microbial indicators of different growth strategies or physiological trade-offs.These findings underscore the close relationship between microbial communities and the health and productivity of Penaeus vannamei.Future studies should focus on optimizing growth performance and balancing it with the immune robustness in P.vannamei.
2025年05期 v.24 1386-1400页 [查看摘要][在线阅读][下载 1157K] - GU Yalan;WANG Jie;DONG Yunwei;
Evaluating species composition and dynamic shifts within fouling communities is essential for developing effective strategies to manage biofouling in marine fish aquaculture. The coastal area in the Yellow Sea is a key area for cage aquaculture in China;however, this region faces significant challenges from biofouling organisms. Here, we employed an experimental approach in a filed mesocosm in a net cage aquaculture area in the Yellow Sea, with weekly monitoring of changes in macrofouling species on mesh nets and in the seawater, to assess the utility of water eDNA metabarcoding for identifying macrofoulers. We compared the temporal variation patterns in the composition and diversity of macrofouling communities identified through morphological method as well as COI and 18S rRNA metabarcoding. The results showed that metabarcoding detected the majority of macrofoulers identified through morphological method(64%), and revealed additional species that were overlooked by traditional monitoring approach. Furthermore, the changes in diversity and community composition over sampling dates in COI data were generally consistent with those in morphological identification, although a temporal lag existed between these two approaches. A notable shift in the fouling community occurred at the end of June with the appearance of Ectopleura crocea and Caprella sp., marking a pivotal change in its structure. Future research could focus on developing targeted primers for these key fouling species, which would enhance the efficiency of monitoring efforts.
2025年05期 v.24 1401-1438页 [查看摘要][在线阅读][下载 1718K] - DONG Xinyu;XI Dongmin;MA Yining;YANG Yongxin;SHI Yan;SUN Jingxin;TAN Yulong;
Bacillus cereus is a significant pathogen responsible for toxin-induced foodborne diseases, and is widely distributed in the natural environment. B. cereus biofilm formation is regulated by multifactorial interactions, demonstrating dynamic adaptability to environmental cues. In this study, crystal violet staining and MTT staining methods were employed to conduct an in-depth investigation into the biofilm formation and metabolic activity changes of five strains of B. cereus in different culture media and with various culture conditions. Experimental data indicated that the composition of the culture medium, the length of incubation time, and the fluctuation of temperature all had a significant impact on the biofilm formation of B. cereus, and this impact exhibited obvious differences among different strains. This result provides a solid experimental basis for deeply elucidating the internal regulatory mechanism of B. cereus biofilm formation and the change principles of metabolic activity.
2025年05期 v.24 1414-1420页 [查看摘要][在线阅读][下载 421K] - XU Mengmeng;YANG Ben;HAN Xiaojie;SUN Deqi;GUO Chao;ZHI Chengjun;LI Qi;LIU Shikai;
The Pacific oyster (Crassostrea gigas) is a primary shellfish species for aquaculture around the world.However,the in dustry of Pacific oyster has been impaired by the mass summer mortality caused by environmental perturbations,including hypoxia Selective breeding of oysters with high hypoxia tolerance is a sustainable approach to prevent economic loss caused by hypoxia.In this study,we constructed 36 C.gigas families and executed the hypoxia stress experiment to estimate genetic parameters for hypo xia tolerance.The survival rate among 36 C.gigas families ranged from 0 to 53.33%,suggesting that high levels of phenotypic varia tion existed in the trait of hypoxia tolerance.Genetic parameters of hypoxia tolerance estimated by six statistical models showed low to moderate heritability,ranging from 0.167 to 0.291.The Pearson and Spearman correlation coefficients among families estimat ed breeding values (EBVs) were high and positive,indicating that different models resulted in similar results in the estimation o breeding values.The phenotypic correlation between growth traits and hypoxia tolerance ranged from-0.030 to 0.061,while geneti correlation ranged from 0.110 to 0.285,implying that growth and hypoxia tolerance were independent traits.This work reported th first estimation of genetic parameters for hypoxia tolerance in C.gigas,and provided valuable information for the genetic improve ment of hypoxia tolerance.
2025年05期 v.24 1421-1427页 [查看摘要][在线阅读][下载 323K] - LI Haimeng;ZHU Congmin;YANG Yuqing;SHU Yuanming;
The assessment of beach quality is an important prerequisite for beach development and serves as the foundation for coastal zone management and sustainable development.This topic has attracted widespread attention,and various evaluation systems have been established.Given that beach quality assessment (BQA) involves multidimensional and nonlinear indicators,machine learning methods are well-suited to handling complex data relationships.However,current research utilizing machine learning for BQA often faces challenges such as limited evaluation indicators and difficulties in obtaining relevant data.in this study,a machine learning-based model for beach quality evaluation is proposed to address the limitations of existing evaluation frameworks,particularly under conditions of data scarcity.Simulated data were generated,and the analytic hierarchy process was integrated to extract features from 21 beach evaluation factors.A comparative analysis was conducted using the following four machine learning models:decision tree,random forest,XGBoost,and MLP.Results indicate that XGBoost (mean squared error (MSE)=0.1825,weighted F1=0.7513) and MLP (Pearson coefficient=0.6053) outperform traditional models.Furthermore,an ensemble learning model combining XGBoost and MLP was developed,substantially improving predictive performance (reducing MSE to 0.0753,increasing the Pearson coefficient to 0.8002,and achieving an F1 score of 0.783).Validation using real data from Yangkou Beach demonstrated that the model maintained an accuracy of 58%even when 5–10 evaluation factors had randomly missing values.
2025年05期 v.24 1428-1435页 [查看摘要][在线阅读][下载 575K] - SONG Hanghang;GAO Pei;ZHANG Xuzhi;CHEN Zhixiang;HAN Xiao;LI Xianguo;ZHANG Dahai;
Bioremediation has gained significant attention due to its potential to remove azo dyes. However, the challenges microorganisms face in surviving when azo dyes are the sole carbon source limit its widespread application. This study aimed to improve the biodegradation of azo dyes by utilizing Baijiu distiller's grains leachate(BDGL) as a co-substrate. The experimental results demonstrated that BDGL significantly enhanced Providencia rettgeri's ability to degrade the model pollutant Acid Black 210(AB210),achieving a decolorization efficiency of 94.5%. This may be attributed to the nutrient-rich composition of BDGL, which includes ethanol and protein, providing a favorable substrate for bacterial growth and activity. The higher biomass and increased activities of azoreductase and quinone oxidoreductase in the BDGL group further supported these findings. Additionally, this method demonstrated broad-spectrum degradation of azo dyes(Direct Red 5B, Acid Red 73, and Congo Red) with different structures, highlighting its potential applicability. Metabolite assays combined with transcriptomics analyses revealed that the expression of functional genes related to redox reactions, azo bond cleavage, and hydrolysis increased under the co-metabolic conditions of BDGL, resulting in stronger reducing power that further mineralized the dye into smaller metabolites. Our study offers a practical strategy for the simultaneous treatment of dye-containing wastewater and Baijiu distiller's grains, with significant environmental and industrial applications.
2025年05期 v.24 1436-1450页 [查看摘要][在线阅读][下载 1137K] 下载本期数据