- JIANG Jindong;SHI Jiuxin;ZHU Yaohua;XU Tengfei;WEI Zexun;
The subantarctic mode water(SAMW) represents a large water mass in the Southern Ocean. This body of water forms through deep convection(subduction) in winter and contributes to the uptake and storage of anthropogenic heat. However, its longterm changes in subduction rate and volume in response to shifting climate conditions are unclear. In this study, we investigated the long-term trend of the subduction rate and volume of the South Pacific–SAMW(SPSAMW) using Simple Ocean Data Assimilation outputs during 1980–2017. The results show the overall increasing trend of the subduction rate of the SPSAMW. The increased subduction of the SPSAMW directly contributes to the volume variation in the SPSAMW. The increased subduction in the South Pacific reached(0.28±0.16) Sv-1 per year, which explains nearly 68% of the volume increase in the SPSAMW. This variability in the SPSAMW reflects alterations in the overlying atmosphere. The positive to negative phase change of the Interdecadal Pacific Oscillation(IPO) in 1980–2017 deepened the Amundsen Sea Low(ASL) via atmospheric teleconnections over the South Pacific. Further analysis reveals that the increased westerly winds during the deepening of ASL resulted in more cold water transport from the south, which deepened the winter mixed layer and thus increased subduction and volume within the SPSAMW subduction region. This finding suggests the association of the long-term trends of SPSAMW subduction and volume with the phase change of the IPO.
2026年01期 v.25 1-12页 [查看摘要][在线阅读][下载 1580K] - WANG Wenjing;WU Caiming;REN Fumin;JIANG Xianling;
In this study, tropical cyclone(TC) translation speed was introduced as a new similarity factor within the generalized initial value(GIV) framework, enhancing the disaster preassessment capability of the dynamical statistical analog ensemble forecast model for landfalling TC disasters(DSAEF＿LTD model). Three TC translation speed indicators most relevant to TC precipitation were incorporated: the maximum speed on Day 1(the first day of TC-induced precipitation and wind occurring on land) and the average and minimum speeds over All Days(all days of TC-induced precipitation and wind occurring on land), all classified using the Kmeans clustering algorithm. Simulation experiments showed that integrating TC translation speed enhanced the model's performance.The model provided a better optimal common scheme, with the TSS UM(sum of threat scores for severe and above and extremely severe and above disasters) increasing by 2.66%(from 0.5117 to 0.5253) compared with the original model. More importantly, its preassessment ability improved significantly, with the average TSS UM for independent samples increasing by 6.43%(from 0.6488 to0.6905). The modified model demonstrated greater accuracy in capturing disaster severity and distribution of TCs with significant speed characteristics or with regular tracks. This improvement stemmed from reduced false alarms due to the selection of analogs that are more similar to the target TC. The enhanced preassessment ability can be attributed to the key role of TC translation speed, which significantly influences TC precipitation patterns and improves TC precipitation forecasting. Since precipitation is one of the most crucial disaster-causing factors, better TC precipitation forecasting leads to improved disaster preassessment outcomes. These findings emphasize the promising potential of the DSAEF＿LTD model for future TC disaster research and management, contributing to the achievement of the Sustainable Development Goals set by the United Nations 2030 Agenda by strengthening coastal resilience.
2026年01期 v.25 13-26页 [查看摘要][在线阅读][下载 1139K] - PENG Yongmao;LI Pengyuan;NI Jing;FU Gang;
Explosive cyclones(ECs) are rapidly intensifying subtropical cyclones that can develop within a short time and pose considerable threats to coastal areas in middle and high latitudes. Gaining a comprehensive understanding of their formation, evolution,and mechanisms of explosive development is essential for improving forecasts of extreme weather events and mitigating associated impacts. Potential vorticity(PV), which is closely related to cyclone dynamics, serves as a valuable diagnostic tool in the study of ECs. In this study, two wintertime ECs of differing intensity over the Northwestern Pacific Ocean are analyzed to examine how different atmospheric processes influence PV generation and the rapid development of ECs. The maximum deepening rates of the two ECs are 2.81 Bergeron(called EC1) and 1.52 Bergeron(referred to as EC2). Results indicate that different stages of EC evolution are closely associated with PV tendency changes at different atmospheric levels. Using the PV tendency equation, during the explosive development of EC1, latent heat release may trigger the downward propagation of upper-level PV. For EC2, latent heat release notably enhances low-level PV, directly contributing to its rapid intensification. To validate these findings, sensitivity tests are conducted using the Weather Research and Forecasting model, with latent heat release turned off in the microphysical scheme for both cases.The results confirm the crucial role of latent heat release in generating low-level PV, further revealing that latent heat release contributes more to the explosive development of EC2 than that of EC1.
2026年01期 v.25 27-37页 [查看摘要][在线阅读][下载 7631K] - ZHAO Shuo;SU Jie;
Arctic sea ice concentration(SIC) prediction on a subseasonal scale plays an important role in polar navigation. To reduce the high uncertainty of daily forecasts, three time series prediction models are combined with empirical orthogonal function(EOF) decomposition to forecast Arctic pentad-mean SIC, where each month is divided into six pentad-means–the first five each span five days, and the last encompasses the remaining days, which may vary in length. The models were trained on SIC data from 1989 to2018 and tested from 2019 to 2023, with lead times ranging from 1 to 12 pentad-means. Model skill was evaluated based on SIC spatial patterns, sea ice area(SIA), and the sea ice edge in September from 2019 to 2023. The moving-averaged 2-m temperature helps reduce the long short-term memory model's error in the Beaufort and Chukchi Seas. Based on the models' scores for each EOF time series, weighted ensemble prediction results were obtained. These results outperform two benchmark models across all lead times. In addition, the ensemble prediction better reproduces the seasonal cycle of the SIA, with relative errors ranging from 1.04% to 3.85%.The predicted September ice edge closely matches observations, with binary accuracy consistently above 90%. Forecast models show the lowest errors in the central Arctic, while relatively higher errors appear in the Barents and Kara Seas.
2026年01期 v.25 38-54页 [查看摘要][在线阅读][下载 3291K] - PANG Junheng;DONG Sheng;
Wind speed is a crucial parameter affecting wind energy utilization. However, its volatility leads to time-varying power output. Herein, a novel Seq2Seq model integrating deep learning, data denoising, and a shape-aware loss function is proposed for accurate multistep wind speed forecasting. In this model, the wind speed data is first denoised using the maximal overlap discrete wavelet transform. Next, an encoder-decoder network based on a temporal convolutional network, bidirectional gated recurrent unit,and multihead self-attention is employed for forecasting. Additionally, to enhance the ability of the model to identify temporal dynamics, a shape-aware loss function, ITILDE-Q, is employed in the model. To verify the effectiveness of the proposed model, a comparative experiment and an ablation experiment were conducted using three datasets of measured wind speeds. Three error metrics and a similarity metric were adopted for comprehensive evaluation. The experimental results showed that the proposed model consistently outperforms benchmark models in all tested forecasting scenarios, with particularly pronounced differences in performance over longer forecast horizons. Furthermore, the synergistic interaction of the three key components contributes to the extraordinary performance of the proposed model.
2026年01期 v.25 55-73页 [查看摘要][在线阅读][下载 4144K] - WANG Lei;FANG Kezhao;ZHOU Long;GONG Lixin;HUO Yongwei;
Waves are important physical phenomena in an ocean, and their accurate prediction is essential for ocean engineering,maritime traffic, and marine early warning systems. This study focuses on the Qinhuangdao Sea area located in the Bohai Sea, China.Herein, we use on-site wind data to correct the reanalysis wind data obtained from the European Centre for Medium-Range Weather Forecasts(ECMWF), improving the accuracy of boundary conditions. Then, we use the Simulating WAves Nearshore(SWAN) model to simulate the regional wave field over time. A regional wave-parameter prediction model is then developed using a limited number of sampled data(covering only 2 years, 2020–2021); the model is based on the Whale Optimization Algorithm(WOA), convolutional neural networks(CNNs), and long short-term memory(LSTM) neural networks. WOA is used to optimize the CNN and LSTM framework; in this framework, CNN extracts spatial features, and the LSTM network captures temporal features, enabling accurate short and long-term predictions of wave height, period, and direction. The experimental results showed that despite the small sample size, the model achieves a goodness of fit of 0.9957 for wave height prediction, 0.9973 for period, and 0.9749 for wave direction in short-term forecasting. As the prediction step size increases, the accuracy of the model decreases. When the prediction step size reaches 9 h, the root mean square error for the prediction of wave height, period, and direction increases to 0.2060 m, 0.4582 s, and32.5358°, respectively. The reliability and applicability of the model are further validated by the experimental results. Our findings highlighted the potential of the developed model in operational wave forecasting, even with a limited number of sampled data.
2026年01期 v.25 74-90页 [查看摘要][在线阅读][下载 3889K] - REN Junqi;LE Conghuan;WANG Kai;ZHANG Puyang;DING Hongyan;
During the hoisting process of the offshore substation, changes in the hoisting speed can affect the hoisting system.Therefore, this study set four different speed conditions for the lifting and lowering stages of the installation process, and studied the impact of different lifting and lowering speeds on the hoisting system under the same environmental conditions through numerical simulation. The results show that during the lifting operation, as the lifting speed increases, the swing motion of the substation and the installation vessel tends to decrease, and the faster the hoisting speed, the more obvious the swing suppression of the substation and the installation vessel, and the smaller the fluctuation in the tension amplitude of the slings and mooring lines. In contrast, during the lowering operation, as the lowering speed increases, the swing motion of the substation and the installation vessel tends to increase,and the faster the lowering speed, the more obvious the swing amplification effect of the substation and the installation vessel. Therefore, during hoisting operations, increasing the lifting speed and reducing the lowering speed can mitigate the motion performance of the hoisting coupling system, reduce the tension amplitude variation of the sling and mooring, and ensure the smooth progress of the hoisting operation.
2026年01期 v.25 91-105页 [查看摘要][在线阅读][下载 3103K] - ZHAO Chunxiao;YANG Yanrui;ZHU Guocan;ZHU Hongchun;
The rapid melting of Arctic sea ice poses significant risks to the safety of shipping routes. Accurate remote sensing data on sea ice concentration(SIC) is crucial for effective route planning of ships and ensuring navigational safety. Despite the availability of numerous SIC products in China, these datasets still lag behind mainstream international products in terms of data accuracy, spatiotemporal resolution, and time span. To enhance the accuracy of China's domestic SIC remote sensing data, this study used the SIC data derived from the passive microwave remote sensing dataset provided by the University of Bremen(BRM-SIC) as a reference to conduct a comprehensive evaluation and analysis of two additional SIC datasets: the dataset derived from the microwave radiation imager(MWRI) aboard the FY-3D satellite, provided by the National Satellite Meteorological Center(FY-SIC), and the dataset obtained through the DT-ASI algorithm from the microwave imager of the FY-3D satellite, provided by Ocean University of China(OUC-SIC). Based on the evaluation results, a TransUnet fusion correction model was developed. The performance of this model was then compared against Ordinary Least Squares(OLS), Random Forest(RF), and UNet correction models, through spatial and temporal analyses. Results indicate that, compared to FY-SIC data, the RMSE of the OUC-SIC data and the standard data is reduced by24.245%, while the R is increased by 12.516%. Overall, the accuracy of OUC-SIC data is superior to that of FY-SIC data. During the research period(2020–2022), the standard deviation(SD) and coefficient of variation(CV) of OUC-SIC were 3.877% and 10.582%,respectively, while those for FY-SIC were 7.836% and 7.982%, respectively. In the study area, compared with OUC-SIC data, FYSIC data exhibited a larger standard deviation of deviation and a smaller coefficient of variation of deviation across most sea areas.These results indicate that the OUC-SIC data exhibit better temporal and spatial stability, whereas the FY-SIC data show stronger relative dimensionless stability. Among the four correction models, all showed improvements over the original, unfused corrected data.The fusion corrections using the OLS, RF, UNet, and TransUnet models reduced RMSE by 5.563%, 14.601%, 42.927%, and48.316%, respectively. Correspondingly, R increased by 0.463%, 1.176%, 3.951%, and 4.342%, respectively. Among these models,TransUnet performed the best, effectively integrating the advantages of FY-SIC and OUC-SIC data and notably improving the overall accuracy and spatiotemporal stability of SIC data.
2026年01期 v.25 106-122页 [查看摘要][在线阅读][下载 2155K] - XU Ziqing;GUO Feng;SUN Fucheng;ZHONG Yinghui;WANG Wei;TIAN Peng;XIAO Jiaguang;NIU Wentao;
Coral reefs worldwide are losing their species diversity and ecosystem function under threats from global warming and anthropogenic activities. In this study, we investigated the diversity and current state of scleractinian corals surrounding the Qizhou Archipelago. A total of 87 species of scleractinian corals, belonging to 29 genera and 12 families, were found across ten survey sites.The family Merulinidae exhibited the highest species richness(39 species and 12 genera), followed by Acroporidae(15 species and 3genera). The living coral coverage was 16.9%±10.3%(mean±SD) and ranged from 4.6% to 35.1%, which varied significantly. Massive corals such as Porites lutea, Porites lobata, Montipora nodosa, and Favites abdita were dominant species. The recruitment rate of coral larvae was(1.20±0.97) ind/m~2(mean±SD). In addition, we constructed an ecological vulnerability assessment system and evaluated the ecological vulnerability of scleractinian corals surrounding the Qizhou Archipelago. The results showed that scleractinian corals at Gouluanpaoshi(GLPS) and Duifan(DF) were highly vulnerable, whereas those on other islands had low to medium vulnerability. In general, the scleractinian corals surrounding the Qizhou Archipelago show low to medium levels of ecological vulnerability. Identifying severely afflicted areas and developing effective methods to manage coral reefs in these regions are crucial.
2026年01期 v.25 123-151页 [查看摘要][在线阅读][下载 3722K] - HUANG Xin;HE Jia;WANG Hao;YAN Fengyuan;KOU Hailei;
In this research, a comparative analysis was conducted on the performance and efficiency of the dual-anchor soft robot(DASR) and the extension-contraction soft robot(ECSR). These robots were constructed by imitating the locomotion of razor clams.The penetration force for extension actuators and the anchorage force for expansion actuators in dry sand with distinct relative densities were tested by differentiating input air pressure and length-to-diameter ratios(λ). On the basis of the findings, a DASR and an ECSR were developed. DASR comprised two expansion actuators as the head and the tail segments at two ends, and one extension actuator as the middle segment. ECSR was composed of an extension actuator. A method based on the force equilibrium was introduced to ascertain and adjust the geometric parameters(length of each segment) of DASR. The burrowing-out performance and efficiency of DASR and ECSR in sands with distinct relative densities were explored. The results revealed that DASR exhibited high efficiency in dense sand in terms of lower time of burrowing-out, slip-to-advancement ratio, and cost of transport. ECSR might perform better in looser sand in terms of higher average burrowing-out velocity, higher advancement in each cycle, and lower energy consumption. However, it had larger slips than DASR. DASR could realize steady advancement and net displacement in each cycle and effectively decrease slips. These findings demonstrate the benefits and usability of the dual-anchor motion and offer new insights into the application of the dual-anchor mechanism in the burrowing of robots.
2026年01期 v.25 133-149页 [查看摘要][在线阅读][下载 2084K] - LI Zhuang;LI Guixiang;SONG Xiangyang;WANG Xinhua;
The continuous decrease in global fishery resources has increased the importance of precise and efficient underwater fish monitoring technology. First, this study proposes an improved underwater target detection framework based on YOLOv8, with the aim of enhancing detection accuracy and the ability to recognize multi-scale targets in blurry and complex underwater environments.A streamlined Vision Transformer(ViT) model is used as the feature extraction backbone, which retains global self-attention feature extraction and accelerates training efficiency. In addition, a detection head named Dynamic Head(DyHead) is introduced, which enhances the efficiency of processing various target sizes through multi-scale feature fusion and adaptive attention modules. Furthermore, a dynamic loss function adjustment method called SlideLoss is employed. This method utilizes sliding window technology to adaptively adjust parameters, which optimizes the detection of challenging targets. The experimental results on the RUOD dataset show that the proposed improved model not only significantly enhances the accuracy of target detection but also increases the efficiency of target detection.
2026年01期 v.25 150-160页 [查看摘要][在线阅读][下载 1201K] - YAO Peng;WANG Yalu;
Accurately estimating depth from underwater monocular images is essential for the target tracking task of unmanned underwater vehicles. This work proposes a method based on the Lpg-Lap Unet architecture. First, the Unet architecture integrates Laplacian pyramid depth residuals and Sobel operators to improve the boundary details in depth images, which may suffer from the feature loss caused by upsampling and the blurriness of underwater images. Multiscale local planar guidance layers then fully exploit the intermediate depth features, and a comprehensive loss function ensures robustness and accuracy. Experimental results on benchmarks demonstrate the effectiveness of Lpg-Lap Unet and its superior performance over state-of-the-art models. An underwater target tracking system is then designed to further validate its real-time capabilities in the AirSim simulation platform.
2026年01期 v.25 161-170页 [查看摘要][在线阅读][下载 818K] - CHENG Haohao;SUO Yanhui;ZHU Dingwei;LI Sanzhong;ZHOU Jie;WANG Pengcheng;DU Xiaodong;WANG Guangzeng;
Quantifying the timing and amplitude of multiple subsidence or uplift stages in sedimentary basins is crucial for understanding their tectonic evolution. In this study, 18 samples from 10 drilling wells in the Pearl River Mouth Basin(PRMB) were subjected to apatite and zircon fission track analyses, and suitable samples were selected for thermal history simulation using Hefty. The thermal history simulation results, combined with balanced cross-section analysis, constrain the Cenozoic tectonothermal history of the PRMB. The results indicate that the PRMB underwent differential uplift in the early Paleogene, followed by regional thermal subsidence in the late Paleogene. Subsequently, the PRMB began tectonic activation in the late Miocene due to the Dongsha movement,marked by two rapid cooling events of ca. 11–6.5 and 6.5 Myr to the present. These cooling events are characterized by a gradual migration from east to west. The first rapid cooling event can be attributed to the NW-SE compressive stress field in the northeastern South China Sea, driven by the clockwise rotation of the Philippine Sea Plate during the late Miocene. The second rapid cooling event is linked to intensive arc-continental collision and the Taiwan Orogeny triggered by the rapid WNW-ward migration of the Philippine Sea Plate.
2026年01期 v.25 171-183页 [查看摘要][在线阅读][下载 3764K] - HU Shouxiang;ZHAO Fang;
Polygonal fault systems(PFS), characterized by multi-directional fault patterns within layered sequences, are well-documented features in global continental margin basins. While the geometry and formation mechanisms of PFS have been extensively studied in the northern South China Sea, the PFS in the Zhongjiannan Basin(western South China Sea) remain relatively unexplored,with a lack of quantitative analysis regarding their propagation. This study addresses this gap by using high-resolution three-dimensional(3D) seismic data and conducting a quantitative fault analysis to thoroughly examine the planform, cross-sectional geometry,and evolution of PFS in the northern Zhongjiannan Basin. The absence of a dominant strike direction among these polygonal faults suggests that their evolution is not controlled by anisotropic stress. Our interpretation of seismic data, constrained by the spatial relationship among PFS, gullies, and pockmarks, indicates that PFS mainly developed within the Miocene strata, with their initiation occurring during the late Miocene. Furthermore, the PFS act as key conduits connecting gullies to pockmarks in this area. The formation and development of PFS may be primarily driven by thermally triggered processes within siliceous sediments. The necessary heat source is probably associated with the abundant submarine magmatism observed in the Zhongjiannan Basin. To reconstruct the regional geological history, a four-stage evolutionary model, incorporating the formation of PFS, is presented. This research significantly improves our understanding of the regional geological evolution of the Zhongjiannan Basin, providing critical insights into the initiation and development of PFS in the western South China Sea.
2026年01期 v.25 184-196页 [查看摘要][在线阅读][下载 4797K] - XIN Yu;YAN Maojun;YAN Zhenwei;WANG Jiping;
Chlorophyll-a is the most abundant chlorophyll pigment produced by marine phytoplankton, and it bears the isotope signature of the nitrate source assimilated in the N-atoms that are embedded in its porphyrin ring. The chloropigment and its degradation product, i.e., pheophytin-a, could be well preserved in marine sediment, usually at nanomolar level. A sensitive and accurate measurement of the δ15N of chloropigment is capable of providing rich information to greatly enhance our understanding of past nitrogen cycling, which therefore is urgently needed. Hereby, we present a successful method based on two-step HPLC separation followed by'denitrifier method'. The N-content in acetone and potassium persulfate(K_2S_2O_8) are very critical to the precision and accuracy of the measurements, because they constitute the majority of the N contamination to the Chl-a samples. In this method, the recrystallized K_2S_2O_8 that is used as oxidization reagent was discovered to have a δ15N background of-15‰, consolidated by repeated examinations over a period of two months. This 15N background of K_2S_2O_8 would cause-1‰–-2‰ deviation on the δ~(15)N of sample that contains nanomolar level N, and highlight the need to examine the δ~(15)N of recrystallized K_2S_2O_8 when it is used to oxidize samples of organic nitrogen. The overall measurement of δ~(15)N pigment is reliable and has an average analytical precision better than ±0.5‰(1σ).This study establish a sensitive method for accurate measurement of the δ~(15)N of nano-molar level chlorophyll pigment, and with no doubts will advance its wide application in marine nitrogen cycling studying.
2026年01期 v.25 197-212页 [查看摘要][在线阅读][下载 853K] - CUI Xin;LI Jianping;FENG Ellias Yuming;
United Nations(UN) encourages sovereign states to take prompt and concrete measures to accomplish net-zero emissions by year 2050, requesting carbon dioxide removal(CDR) technologies to be prepared and implemented in such ambitious climate action roadmap. However, whether CDR technologies should be further promoted or discontinued post net-zero emission year remains unclear. In this Earth-system modelling research, we compare UN-suggested 2050 net-zero emission scenario against other common climate mitigation scenarios outlined by shared social-economic pathways(SSPs). We also simulate continued CDR implementations after net-zero emissions, which is hypothetically achieved in year 2050 and 2070 respectively, to investigate how CDR can impact the global climate throughout the whole 21st and 22nd centuries. The modelling results find if the 2050 UN net-zero emission goal is accomplished, the global average surface air temperature(SAT) in the end of 21st century is around 1.5 ℃ higher compared to the pre-industrial level, promising an Earth environment more habitable than other scenarios without CDR. When CDR is applied to remove equal amount of anthropogenic CO_2 emissions since industrial revolution, it restores the global average SAT close to pre-industrial level of 13.5 ℃. However, CDR-induced global carbon distribution within ocean, atmosphere, and land pools is different from the pre-industrial condition, causing reduced atmospheric CO_2 concentration by 9 to 38 ppm compared to the pre-industrial cases, and more alkalinized ocean surface with pH increase of 0.004 to 0.024. This study affirms CDR cannot be viewed as a reversed process to anthropogenic CO_2 emissions, accordingly climate policies to overcome the uncertainties after for late 21st century still require careful trade-offs for the decarbonation and the cost-benefits of CDR measures.
2026年01期 v.25 207-216页 [查看摘要][在线阅读][下载 880K] - ZHONG Guangsheng;QU Bo;
An atmospheric general circulation model(AGCM) is used to analyze the different impact on the Barents Sea(BS) and Greenland Sea(GS) for a perturbation of sea-to-air DMS flux. We compare contemporary anthropogenic S and contemporary DMS sea-to-air flux(as baseline, B00) sulfur emissions, with contemporary anthropogenic S and a perturbed DMS flux(as modified, B01)sulfur emissions. Results show that the global mean surface DMS and DMS vertically integrated concentration all peaked in June and increases more than 63% in BS and increases about 58% in GS. The concentrations of atmospheric sulfur dioxide vertical integral(SO_2) and sulfate vertical integral(SO_4) only increase less than 12% in both regions. Sulfur emission(SEM) peaked in June and increased about 67% and 41% in GS and BS, respectively. Aerosol optical depth(AOD) increases less than 4% in GS and in BS. Surface temperature(TSC) peaked in July and reduces 0.25 K and 0.8 K in GS and BS, respectively. Satellite data from 2003 to 2023show that chlorophyll(CHL) concentration in BS exceeds that of GS by 51%. The AOD in GS is only 0.6% higher than in BS. The recent increased rate of DMS surface concentration in BS(from 6% during 1981–2002 to 18.8% in 2003–2023) is mainly caused by elevated CHL concentrations in BS. Finally, the perturbation on DMS flux leads to increase rate of DMS and related sulfur emissions especially in the BS, this tendency will have an offsetting effect on regional warming.
2026年01期 v.25 217-227页 [查看摘要][在线阅读][下载 1033K] - GAO Siru;WANG Hongsong;LV Jiayi;ZHAN Yuanchao;
Viral infections play a crucial role in marine biogeochemical cycles, by regulating bacterial mortality and mediating nutrient and carbon fluxes. However, despite of their ecological significance, existing climate change models generally fail to incorporate virus-mediated ecological processes due to the current limited understanding of marine viral dynamics under global warming.While numerous studies have explored the effect of warming for viral decay and production, how temperature regulates the total abundance of marine viruses remains unclear. In this study, we conducted year-round measurements of viral production and decay rates in Qingdao's coastal waters, with additional experimental warming treatments. The result showed that under in-situ temperature,the viral decay and production rate displayed distinct seasonal variations. With the exception of summer, elevated temperature stimulated both viral decay rate and production rate, and further improved the net viral production rate. While in summer, the net viral production rate turned negative, implying divergent threshold viral decay and viral production rate on warming. Our study deepens the understanding of the effect of global warming on marine viruses and provides scientific data for climate change models.
2026年01期 v.25 228-236页 [查看摘要][在线阅读][下载 633K]
- GAO Shan;LIAO Wuquan;CUI Yuhang;LIN Zexu;SHI Gang;WANG Ping;SUN Chengbo;
The conservation of aquatic systems is closely linked to the maintenance and improvement of aquaculture products' yield and quality. In this experiment, a high-quality aquatic system was established, comprising Litopenaeus vannamei as a model species and two strains of Bacillus(W1 and XYB4) combined with sodium humate under zero-water exchange conditions. The growth performance, enzyme activity, and aquatic system microbial environment of L. vannamei were analyzed. Results showed that the combination of sodium humate and Bacillus strains effectively enhanced environmental conditions for the growth and reproduction of heterotrophic bacteria while inhibiting the growth of Vibrio species, including green and yellow variants. Microbiome analysis showed that the group treated with Bacillus strains combined with sodium humate exhibited significantly higher relative abundances of Firmicutes and Actinobacteriota than the other groups. Correspondingly, this treatment group showed substantially enhanced weight gain rate, specific growth rate, survival rate, and feed coefficient. Moreover, the phenol oxidase, catalase, lysozyme, and superoxide dismutase indexes of shrimps subjected to Bacillus–sodium humate treatment were considerably higher than those of the control group.These findings confirm that the combination of Bacillus and sodium humate has beneficial effects on shrimp growth and aquatic system quality control, providing a promising strategy for enhancing the efficiency of shrimp farming and aquaculture.
2026年01期 v.25 237-246页 [查看摘要][在线阅读][下载 549K] - XU Ning;ZHANG Xiaoxin;WANG Yunfeng;ZHANG Qianqian;
Ciliates are a dominant group in the marine sediment microecosystem, and their interactions with symbiotic prokaryotes are important for understanding the adaptation mechanisms of marine benthic eukaryotes. However, the microbial communities(microbiome) associated with most benthic ciliates and the taxonomic attributes of the dominant symbiotic bacteria are unclear. In this study, we focused on Paraspathidium apofuscum, a ciliate prevalent in marine benthic environments, and comprehensively explored the diversity and cellular location of the microbiomes in two P. apofuscum isolates using single-cell-based full-length16S rRNA amplicon sequencing, phylogenetic analysis, and fluorescence in situ hybridization. The results showed that the P. apofuscum cell surface carried a highly diverse microbiome whose cellular localization was consistent with the positions of the ciliate's somatic dikinetids. The dominant genera in the microbiome, Pseudoalteromonas, Halobacteriovorax and Oceaniserpentilla, were associated with unicellular eukaryotes. In particular, Pseudoalteromonas likely uses ciliate-secreted metabolites as nutrients and plays a role in host physical protection or pathogen resistance. Halobacteriovorax and Oceaniserpentilla are newly discovered or rare bacterial genera innovatively found to have ecological niches in symbiosis with benthic ciliates. Comparison analysis indicates that the microbiomes associated with benthic ciliates display species and population specificity, which are attributed to several factors such as environmental physicochemical properties, host physiological states, and interactions among associated bacteria. This study provides important insights into the environmental adaptation of eukaryotes through a symbiotic mechanism in the marine benthic environment.
2026年01期 v.25 247-262页 [查看摘要][在线阅读][下载 1770K] - CHENG Geng;HU Hong;LIANG Yuanxin;BI Wenlong;XU Chengxun;LIU Haijun;LI Qi;
Triploid Pacific oysters(Crassostrea gigas) are highly valued due to their rapid growth and low fertility, making them commercially desirable. However, these reproductive characteristics also hinder their capability to produce subsequent generations.Large-scale triploid production relies on crossing female diploid and male tetraploid oysters. This study assessed the effects of shell morphology on body weight and fecundity in diploid and tetraploid oysters using multiple regression and path analysis. Substantial correlations were found between shell morphology and body weight traits, as well as between shell morphology and fecundity traits across diploid and tetraploid oysters. Path analysis revealed that shell morphology traits significantly impact body weight and fecundity in both diploids and tetraploids. Among these traits, shell height had the strongest direct effect on body weight and fecundity,while shell height and shell length notably contributed through indirect effects. These findings highlight the importance of shell height in shaping body weight and fecundity in diploid and tetraploid Pacific oysters, indicating that selective breeding, with a particular focus on enhancing shell height, could simultaneously promote increases in shell length.
2026年01期 v.25 263-272页 [查看摘要][在线阅读][下载 526K] - JIANG Hui;QU Peng;YU Xiaojun;ZHANG Yuanming;JIANG Linshan;ZHANG Chengwei;MAI Kangsen;ZHANG Wenbing;
The present study investigated the effects of varying protein source combinations and feeding strategies on the growth,health and organoleptic quality of the large yellow croaker(Larimichthys crocea). Three iso-nitrogenous and iso-lipidic diets were formulated. The control diet was made with 62% fish meal(FM). The other two experimental diets were formulated by replacing 45%FM with 22.5% mealworm(TM) and 22.5% cottonseed protein concentrate(CPC), or with 22.5% TM and 22.5% Clostridium autoethanogenum protein(CAP), respectively. The three kinds of diet were named as A1, A2 and A3, respectively. Five groups of large yellow croaker were fed with two different strategies: the first three groups were continuously fed with A1, A2 and A3 diets, respectively. The fourth group was alternately fed with A1 and A2 diet every 5 days. The fifth group was alternately fed with A1 and A3diet every 5 days. The five groups were named D1, D2, D3, D1-2 and D1-3, respectively. Results showed that D2 and D3 groups exhibited significantly lower weight gain rate(WGR) and higher feed conversion ratios(FCR) compared to the D1 group. The D1-2 and D1-3 groups exhibited improved WGR and significantly reduced FCR compared to the D2 and D3 groups. The A2 and A3 diets significantly suppressed digestive enzymes' activities compared to A1, whereas alternate-feeding groups significantly enhanced the enzyme activities. Compared to the D1 group, D2 and D3 groups significantly downregulated mRNA expression levels of intestinal antiinflammatory cytokines and upregulated the expression of pro-inflammatory mediators. The anti-inflammatory abilities in the D1-2and D1-3 groups were significantly higher than those in the D2 and D3 groups. Additionally, diets containing TM+CAP and TM+CPC protein sources enhanced ventral redness and yellowness indices. Considering the growth, digestion, immunity and organoleptic quality of large yellow croaker, it is recommended to replace up to 45% of FM with TM+CPC and use an alternate-feeding strategy.
2026年01期 v.25 273-289页 [查看摘要][在线阅读][下载 948K] - YANG Yihui;HUANG Tao;PENG Shiyi;YANG Wenge;XU Lianying;ZHAN Shengnan;
Carbon dots(CDs), nanoscale carbon-based particles ubiquitously present in thermally processed foods such as toasted products, exhibit exceptional structural stability even after gastrointestinal digestion, a property that facilitates their systemic absorption and bioaccumulation. Their persistence in biological systems enables direct interactions with small bioactive molecules, potentially modulating the functional properties of dietary components. This study systematically evaluates the impact of CDs on the antioxidant efficacy of tea polyphenols(TPs), a class of natural antioxidants widely recognized for their health-promoting effects. The structure, antioxidant capacity, and in vitro cytological effects of the CDs-TPs complex were also investigated. Our results demonstrate that CDs and TPs form stable complexes mediated by non-covalent interactions, with hydrogen bonding identified as the dominant mechanism–specifically between the phenolic hydroxyl groups of TPs and fluorescent carbon-rich domains on CDs. These interactions induced a concentration-dependent enhancement in fluorescence intensity, with optimal binding efficiency observed at low CDs/TPs molar ratios(1:1 and 10:1). Structural analyses revealed that TP binding altered the tertiary conformation of CDs, exposing additional luminescent sites and modifying surface charge distribution. Transcriptomic profiling further demonstrated dose-dependent increases in differentially expressed genes under higher CDs/TPs ratios, which were predominantly enriched in oxidative stress response pathways. Mechanistic studies identified the FoxO signaling pathway as a central regulatory axis, with CDs-TPs complexes modulating the expression of antioxidant-related genes(e.g., SOD2) and downstream effectors involved in redox homeostasis. These findings not only elucidate the structure-function interplay governing CDs-TPs interactions, but also highlight their dual role as modulators of antioxidant activity and potential therapeutic agents, establishing a foundation for developing CD-based composite materials in targeted antioxidant therapies.
2026年01期 v.25 290-300页 [查看摘要][在线阅读][下载 893K] - JING Qianqian;CHENG Yajie;WANG Wenhui;YIN Junna;WEI Meiyan;XU Tongyi;SHAO Changlun;
Mycobacterium marinum can cause disease in both human beings and fishes. Infected fish exhibits symptoms commonly referred to as fish tuberculosis. In this research, we screened a 14-Membered Resorcylic Acid Lactones(RALs) library constructed in the laboratory for in vitro anti-Mycobacterium marinum activity and found that several compounds, including compounds 3, 4, 6, 10,and 17–26, showed good activity. Notably, the trace natural product cochilimycin B(compound 3) possesses significant long-lasting inhibitory function to Mycobacterium marinum. It also shows synergistic effects with drugs like isoniazid, ethambutol, and bedaquiline(FICI≤0.5). In addition, cochilimycin B showed a significant inhibitory effect on the biofilm produced by Mycobacterium marinum, with an inhibition rate of 65.9%. To solve the bottleneck problem of natural product drug sources, we realized an efficient one-step semi-synthetic method to obtain compound 3 with a yield of 32.1%. In vivo, inflammatory changes in BALB/c mice infected with Mycobacterium marinum were characterized. After 12 h of infection, IL-1β was 20%–30% lower in the spleen and tail of the3-treated group compared to the control group. In the thymus and tail of the treated group, TNF-α levels were 30%–60% lower than in the control group. This is the first time that the significant anti-Mycobacterium marinum effect of cochilimycin B from 14-Membered Resorcylic Acid Lactones(14-RALs) was reported, offering a new chemical molecule for anti-Mycobacterium marinum drug research.
2026年01期 v.25 301-329页 [查看摘要][在线阅读][下载 1699K] - XUE Yadong;HAN Ping;LIU Xiumei;CHEN Jianming;YUAN Mingzhe;WANG Xubo;
Polyfluoroalkyl substances(PFAS) have emerged as persistent environmental contaminants because of their chemical stability, degradation-resistance and bioaccumulation potential. However, current studies mainly focus on the toxicity of single PFAS such as perfluorooctanoic acid(PFOA) and perfluorobutanoic acid(PFBA), the knowledge of their combined effects is relatively limited. In this study, we explored the immune response of the gut in large yellow croaker(Larimichthys crocea) under the combined stress of PFOA and PFBA. Histologicalanalyses revealed that the combined effect induced intestinal vacuolization and decreased the length of intestinal villi. And it significantly activated pro-inflammatory pathways with marked upregulation of tnfα, il1β, il6 and myd88 expressions, particularly after 14 days of exposure. Gut microbiota analysis revealed substantial dysbiosis, including 1) reduced alpha diversity, 2) increased abundance of potential pathogenic taxa(Proteobacteria and Spirochaetota), and 3) depletion of beneficial Firmicutes. PICRUSt-based functional prediction indicated temporal metabolic shifts, with upregulation of DNA repair pathways at day 3 and enhanced bacterial motility protein activity at days 7 and 14 of post-exposure. The Pearson correlation analysis further indicated that these immune genes had significant positive correlations with Vibrio and Brevinema, and negative correlations with Streptococcus. Our present study will provide novel insights into the microbiome-mediated immunomodulation in the larger yellow croaker exposed to combined PFAS, which will be helpful for healthy farming of economically important marine species.
2026年01期 v.25 312-322页 [查看摘要][在线阅读][下载 1039K] - MA Qianhui;WANG Qiaohan;LIU Yan;GONG Qingli;LI Huiru;GAO Xu;
Sargassum muticum is a globally distributed seaweed with high economic potential, yet its detailed nutritional composition remains undercharacterized. In this study, we analyzed the nutritional profiles of five thallus portions, namely apical fronds, middle fronds, basal fronds, receptacles and air bladders, to assess their economic value accordingly. Results showed that middle fronds had the highest crude protein(31.98%) and crude fiber(7.10%) contents, indicating their suitability for protein-rich functional foods or dietary fiber supplements. Receptacles exhibited the highest levels of crude lipid(1.11%) and polyunsaturated fatty acids(123.01mg/g), suggesting potential for bioactive lipid extraction in nutraceutical applications. By contrast, basal fronds were enriched in saturated(86.41 mg/g) and monounsaturated fatty acids(38.38 mg/g). The essential amino acid index ranged from 0.74 to 0.87, and total amino acid content peaked in middle fronds(77.90 mg/g), highlighting their high protein quality. Apical fronds had the highest calcium content(15611.95 mg/kg), and receptacles contained the highest phosphorus content(1224.45 mg/kg), supporting targeted mineral supplementation. The maximum concentrations of all trace elements were found in receptacles, reinforcing their pharmaceutical potential. This study provides foundational data on the nutrient composition of different thallus parts of S. muticum, which may support future research and potential utilization efforts in China.
2026年01期 v.25 323-332页 [查看摘要][在线阅读][下载 325K] - LI Jing;WANG Yu;XU Tao;KONG Lingfeng;LI Qi;
The Chamidae are widely distributed in the tropical to temperate seas, with >70 known species. Currently, their classification relies mainly on traditional morphological methods and identification primarily on small fragment genes, such as COI. The intrafamily phylogenetic relationships are ambiguous, lacking support from reliable molecular data. In this study, the mitochondrial genomes of eight species of Chamidae were sequenced for the first time and then annotated. Their structures and compositional characteristics were analyzed. The mitochondrial gene order in this family differed significantly. Concurrently, the evolutionary position and phylogenetic relationship among Chamidae species were explored, and the Veneroida phylogenetic tree was recreated. Maximum Likelihood and Bayesian Inference analyses supported the monophyly of Chamidae. Additionally, the divergence time within Chamidae was estimated based on mitochondrial DNA sequences, with the most ancient divergence estimated to occur during the early Cretaceous period, 128 MYA. This phylogeny is significant for understanding the diversity and taxonomic status of Chamidae.
2026年01期 v.25 333-342页 [查看摘要][在线阅读][下载 662K] - ZHAO Lianwen;CHU Chang;STOECK Thorsten;LU Haohao;JIANG Jiamei;WU Xugan;PAN Hongbo;
Open earthen pond-based larviculture is the main method for rearing Chinese mitten crab(Eriocheir sinensis) larvae in China. Bacterioplankton play a vital role in aquaculture ecosystems, but their community succession throughout the larval nursery stages of E. sinensis in such systems is still poorly understood. Using 16S rRNA gene amplicon sequencing, this study characterized the dynamics of bacterioplankton communities during a complete E. sinensis larval rearing cycle in open earthen ponds. Results presented a distinct, unidirectional succession in bacterioplankton composition, characterized by a decrease in Alphaproteobacteria and an increase in Actinobacteria. Live feeds(Brachionus plicatilis and Artemia salina) significantly affected bacterioplankton communities directly through their biological activities and indirectly by modifying the structure of phytoplankton composition. In addition to live feeds, water temperature and dissolved oxygen were key environmental factors affecting the structure of bacterioplankton communities. Biotic interactions, specifically with phytoplankton and copepods, were key drivers of bacterioplankton succession. Routine feeding practices during larval cultivation decreased bacterioplankton network complexity and strengthened community stability.Keystone taxa, specifically OTU783(Rhodobacteraceae) and OTU1235(Microbacteriaceae), played an essential role in maintaining the community stability through recruiting more rare species during the later stages despite their low abundances. These outcomes advance our understanding of the mechanisms central to bacterioplankton community succession and stability in E. sinensis larviculture systems, offering critical insights for developing sustainable aquaculture management strategies.
2026年01期 v.25 343-359页 [查看摘要][在线阅读][下载 1263K] - WANG Yixuan;YU Mingming;WANG Cong;
Coenzyme Q10 and vitamin E are among the most widely consumed nutritional supplements in China owing to their antioxidant and other health-promoting properties. This study aimed to establish an accurate and efficient analytical method for the simultaneous determination of these two compounds in commercial softgel capsules, which is essential for rigorous quality control.Herein, a proton nuclear magnetic resonance(1H NMR) method was developed and validated using coumarin as an internal standard.Characteristic signals at 3.997 ppm for coenzyme Q10 and 2.621 ppm for vitamin E were selected for quantification. The method demonstrated excellent performance in terms of precision(relative standard deviation <2%), specificity(resolution >1.5), and stability(24-h variation <3%). The validation results complied with the China Food and Drug Administration guidelines, demonstrating high accuracy. Application to products from four different manufacturers showed compound contents ranging from 98.2% to 102.4%of label amounts. These findings support ~1H NMR spectroscopy as a rapid, precise, and reliable approach for the simultaneous quality assessment of coenzyme Q10 and vitamin E formulations.
2026年01期 v.25 353-358页 [查看摘要][在线阅读][下载 406K] - LIU Xinqiang;WANG Wenxin;BI Haisong;LIN Shilin;WANG Zheng;QIAN Chengduo;LIN Jiushu;JI Junyuan;
A novel salt-tolerant aerobic denitrifying bacterium,Marinobacter sp.strain B108,was isolated from a marine recirculating aquaculture system (MRAS).The optimal aerobic denitrification parameters were CH_3COONa as carbon source,pH of 8,C/N of16,temperature of 35°C,dissolved oxygen (DO) of 6 mg/L and salinity of 30.Under these optimal conditions,Marinobacter sp.strain B108 had a removal efficiency of 100%for N O_3~--N and 98.89%for total nitrogen (TN) within 24 h.The nitrate removal pathways of Marinobacter sp.strain B108 were included by the assimilative reduction pathway (N O_3~--N→biomass N) and the dissimilatory reduction pathway (N O_3~--N→N_2) of aerobic denitrification,and lack of dissimilatory reduction to ammonium pathway (N O_3~--N→N H_4~+-N).The nitrogen removal process of Marinobacter sp.strain B108 was mainly contributed by the dissimilatory reduction pathway.The kinetic parameters for N O_3~--N and N O_2~--N removal were determined as V_m of 971.566 and 165.336 mg/(gDCW·L·h),and K_m of 22.74 and 31.68 mg/L,respectively.This work reflects the practical application potential of Marinobacter sp.strain B108for nitrogen removal in MRAS.
2026年01期 v.25 359-370页 [查看摘要][在线阅读][下载 764K] 下载本期数据