Journal of Marine Systems最新文献

{"title":"Vertical velocity in the deep layer of South China Sea revealed by using ECCO product","authors":"Jianing Li ,&nbsp;Qingxuan Yang ,&nbsp;Hui Sun","doi":"10.1016/j.jmarsys.2025.104110","DOIUrl":"10.1016/j.jmarsys.2025.104110","url":null,"abstract":"<div><div>Unlike the well-studied South China Sea (SCS) horizontal circulation, the vertical velocity in the SCS, especially in the deep water, is poorly understood. The vertical velocity connects the horizontal circulations at different depths and plays vital roles in modulating vertical material transport and biochemical processes. Using the ECCO4 product, we investigate the distribution of vertical velocities in the deep SCS, and explore the renewal process of the SCS deep water. The vertical velocities deeper than 2500 m all present similar spatial features: the downwelling originates near the Luzon Strait and spreads to the SCS basin interior, while the upwelling mainly takes place near the continental slope and forms an upwelling ring around the downwelling zone. This pattern becomes more and more significant with depth and is temporally stable. The upwelling near the continental slope is dominantly contributed by its diapycnal component, indicating a strong relation to local mixing. The near-bottom vertical velocity field shows a similar spatial-temporal pattern. This vertical velocity distribution suggests the deep-water overflow from the Luzon Strait is the main driving factor of the SCS deep water recycling. The Pacific deep water first sinks into the deep basin interior to supply the SCS deep water; then, it upwells along the slope and returns to the middle layer to accomplish the SCS deep water renewal. These findings not only improve our understanding of the three-dimensional circulation in the SCS, but also serve as an enlightenment for the uplifting of the deep and bottom waters in the open ocean.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"251 ","pages":"Article 104110"},"PeriodicalIF":2.7,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144704778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Drivers of the unprecedented coastal marine heatwaves along Fujian and Zhejiang provinces, China","authors":"Yulong Yao ,&nbsp;Yuwei Hu ,&nbsp;Chuanming Hu ,&nbsp;Chunzai Wang ,&nbsp;Wenwen Yu","doi":"10.1016/j.jmarsys.2025.104108","DOIUrl":"10.1016/j.jmarsys.2025.104108","url":null,"abstract":"<div><div>In recent decades, coastal marine heatwaves (MHWs) have intensified due to global warming, causing severe impacts on coastal marine ecosystems. In September and October 2021, significant reductions in seaweed production were observed along the coasts of Fujian (−19.23 %) and Zhejiang (−3.27 %) Provinces in China, which may be related to unprecedented coastal MHWs. This study utilizes three high-resolution satellite sea surface temperature (SST) datasets together with oceanic and atmospheric reanalysis products to examine the characteristics and mechanisms of these MHWs. Our analysis reveals that the record-breaking MHWs occurred primarily from September 21 to October 23, with an average intensity of up to 4 °C and lasting nearly the entire month of October. Mixed layer heat budget assessments indicate that net surface heat flux was the key factor influencing temperature changes (Corr = 0.71, <em>p</em> &lt; 0.01). The positive net surface heat flux in September, driven by increased solar shortwave radiation, resulted from the intensification and westward expansion of the western Pacific subtropical high (WPSH). We emphasize that understanding the mechanisms behind the anomalous WPSH in autumn is vital for mitigating climate risks to seaweed production along the Fujian and Zhejiang coasts in the context of global warming.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"251 ","pages":"Article 104108"},"PeriodicalIF":2.7,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144671343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Response of estuary ecosystem to El Niño event: A case study in the Yangtze River Estuary","authors":"Wen Wang ,&nbsp;Gan Chen ,&nbsp;Rongrong Zhao ,&nbsp;Chunxia Gao ,&nbsp;Jianhui Wu ,&nbsp;Dongyan Han","doi":"10.1016/j.jmarsys.2025.104120","DOIUrl":"10.1016/j.jmarsys.2025.104120","url":null,"abstract":"<div><div>The knowledge of how the Yangtze River Estuary (YRE) ecosystem responds to and adapts to the El Niño events is limited but cannot be ignored. Based on the fishery survey data in the YRE in 2013, 2015, and 2017, we constructed and compared three Ecopath models representing three different periods: before, during, and after El Niño event. Results showed that the YRE ecosystem underwent significant change after the occurrence of El Niño. Biomass of phytoplankton and zooplankton increased substantially during the El Niño period, while the biomass of most fish groups and shrimp decreased. During the El Niño period, the YRE ecosystem exhibited low mean trophic levels and low energy transfer efficiency; some ecological network measurements (TPP/TR, TPP/TB, FCI) indicated a more fragile and highly disturbed ecosystem. After the EI Niño event, most of these changes recovered to varying degrees, with species in grazing food chain recovering faster than in detrital based food chain. The variations from 2013 to 2017 reflected the complex impact mechanism of EI Niño on the ecosystem, as well as its resilience after climate disturbance. This study enhances our understanding of how estuarine ecosystems respond to climate events, and may serve as a reference for the development of adaptive management strategies under climate change.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"251 ","pages":"Article 104120"},"PeriodicalIF":2.5,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144896027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prediction of Arctic kelp forest occurrence using Extreme Gradient Boosting","authors":"Klaudia Kosek ,&nbsp;Wojciech Artichowicz ,&nbsp;Piotr Balazy ,&nbsp;Bernabé Moreno ,&nbsp;Maciej Chełchowski ,&nbsp;Piotr Kukliński","doi":"10.1016/j.jmarsys.2025.104118","DOIUrl":"10.1016/j.jmarsys.2025.104118","url":null,"abstract":"<div><div>Kelp forests are one of the most productive marine habitats of the world that provide number of valuable ecosystem services for diverse range of species. Understanding the physicochemical factors influencing kelp forest occurrence is vital for comprehending its ecosystems' dynamics. That seems especially important in Arctic environments which are strongly influenced by climate change. Therefore, a high-Arctic fjord (Isfjorden), was selected as a model system to investigate the influential parameters for kelp forest occurrence using a binary classification model - Extreme Gradient Boosting (XGBoost). For this purpose, a set of physicochemical parameters, including water masses flow velocity, electrical conductivity (EC), pH, oxygen, light intensity and temperature, were measured at various depths and locations within kelp forest sites and areas without them. Analyses have shown the possibility of effectively predicting kelp forest occurrence using machine learning based on the measured values of the physicochemical parameters. Additionally, the feature importance analysis of the developed XGBoost model revealed the significance of each parameter in the kelp forest occurrence prediction. The created model demonstrated exceptional predictive performance, accurately distinguishing between kelp forest-associated and kelp forest-barren sites with an AUC (Area Under the Curve) of 0.999. This study serves as a foundation for further research on kelp ecosystems worldwide, emphasizing the significance of employing mathematical modeling approaches to unravel the factors governing kelp forest distribution and growth.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"251 ","pages":"Article 104118"},"PeriodicalIF":2.5,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144860647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Traits associated with food web structure in lagoon and reef ecosystems","authors":"Ana Luisa Avelino Brito ,&nbsp;Tibor Kalapos ,&nbsp;Ferenc Jordán ,&nbsp;Katalin Patonai","doi":"10.1016/j.jmarsys.2025.104095","DOIUrl":"10.1016/j.jmarsys.2025.104095","url":null,"abstract":"<div><div>The oceans are currently facing multiple anthropogenic threats, such as overexploitation, pollution, habitat destruction, and climate change. To address these challenges, ecological indicators are needed to monitor the impact of human activities and assess the effectiveness of conservation measures. Food web topology captures the entire community structure, providing systems-based indicators of ecological status rather than monitoring single species and their composition. In this study, the association between functional organismic traits and topological indices describing the food web structure was tested by using network analysis in 4 reef and 15 lagoon Ecopath with Ecosim models. We aimed to understand if traits and conservation status can be linked with specific network position of a node. We analyzed 3 traits (diet, fertilization type, substratum), conservation status, and 18 topological indices. The results showed at least two significant associations for each trait. Conservation status, fertilization type, and diet displayed more distinct aggregations, being relevant in explaining food web structure. Conservation status aggregated top predators in a risk position (endangered or vulnerable) and also those with fewer network connections. Fertilization type (external, internal, or asexual) could be considered a good grouping trait. Diet has the highest coverage and revealed expected patterns, which can be very helpful for environmental predictions under disturbances, using the trait-based approach. Substratum is the least useful trait for this approach. The associations of ecological traits and topological indices in lagoon and reef food webs might help in conservation “ecosystem-based” management decision-making and prioritization.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"251 ","pages":"Article 104095"},"PeriodicalIF":2.7,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144653213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Coffin Bay Estuary: Influences from coastal upwelling in the eastern Great Australian Bight","authors":"Jochen Kämpf","doi":"10.1016/j.jmarsys.2025.104112","DOIUrl":"10.1016/j.jmarsys.2025.104112","url":null,"abstract":"<div><div>Using a coupled physical-biological model at different grid resolutions, this work explores the influences from coastal upwelling on the Coffin Bay Estuary in the eastern Great Australian Bight. The Coffin Bay Estuary, which is a negative estuary, consists of a series of interconnected smaller bay. The findings show the main upwelling plume is topographically steered around but does not enter the Coffin Bay Estuary. Instead, the nitrogen load in seawaters near the estuary is derived from secondary circulations and horizontal turbulence. However, due to photosynthetic consumption in the main upwelling zone, dissolved nitrogen levels are reduced to low values (∼0.8 μM) near the estuary and can only support slow phytoplankton growth. While wind-driven currents rapidly flush the outer bay of the estuary, called Coffin Bay, on a timescale of 5 days, this excludes shallower (&lt;20 m) nearshore water that has a turnover time &gt; 40 days. However, it is this shallower water that is connected to the first inner bay of the estuary, Port Douglas Bay, via strong (&gt;1 m/s) tidal flows in the narrow channel. The other inner bays of the estuary have flushing times &gt;100 days and are not influenced by processes on the ambient continental shelf. Hence, the coastal upwelling region in the eastern Great Australian Bight has generally no or only little influence on the nutrient budget in the Coffin Bay Estuary.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"251 ","pages":"Article 104112"},"PeriodicalIF":2.7,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144703529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diagnostic early freeze onset in the Bering Sea","authors":"Weibo Wang ,&nbsp;Jie Su ,&nbsp;Junpeng Zhang ,&nbsp;Rui Ding ,&nbsp;Chunsheng Jing ,&nbsp;Xiaogang Guo","doi":"10.1016/j.jmarsys.2025.104106","DOIUrl":"10.1016/j.jmarsys.2025.104106","url":null,"abstract":"<div><div>Sea ice cover exerts critical influence on oceanic, atmospheric, and ecological processes in the Bering Sea. As a fundamental indicator of ice formation, diagnostic research on Early Freeze Onset (EFO) characteristics remains limited. This study examines the spatiotemporal patterns and underlying mechanisms governing the Bering Sea EFO from 2003 to 2021, leveraging the latest microwave remote sensing dataset. The annual EFO in the Bering Sea exhibits a temporal evolution characterized by positive anomalies (2003−2013) followed by marked negative anomalies (2014–2021). Spatially, the most pronounced contrast between the two periods occurs over the continental shelf south of St. Lawrence Island. A spatial restructuring of EFO beginning in 2014—particularly its shift from positive to negative anomalies on the northern Bering Sea shelf—drives the observed temporal variability. This spatial shift stems from preceding meridional sea surface temperature gradient anomalies, triggering a regime shift in Bering Sea warm advection from negative forcing (2003–2013) to positive forcing (2014–2021). Notably, frequent marine heatwave events during 2014–2021 cause abnormal pre-freeze SST warming in southern St. Lawrence Island waters, compounded by suppressed northward heat export. This dual process amplified heat accumulation, ultimately resulting in earlier EFO. This study emphasizes the need to strengthen research on marine heatwaves in the future, and comprehend the repercussions of EFO on ecosystems, fisheries, and local community livelihoods, to devise adaptive management strategies and policies.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"251 ","pages":"Article 104106"},"PeriodicalIF":2.5,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144773188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seasonal and decadal variations in nutrients and organic carbon in the lower Huanghe River under drastically changing water-sediment regimes","authors":"Xintong Jiang ,&nbsp;Yue Ming ,&nbsp;Mengyu Wang ,&nbsp;Ailin Yao ,&nbsp;Xianye Wang ,&nbsp;Lei Gao","doi":"10.1016/j.jmarsys.2025.104111","DOIUrl":"10.1016/j.jmarsys.2025.104111","url":null,"abstract":"<div><div>The Huanghe (Yellow) River is well known for its sediment-laden river waters, and it is also a typical large river deeply imprinted by human activities. Surface water samples were collected monthly from March 2019 to October 2022 at the Luokou station in its lower reaches, to elucidate the seasonal variation patterns of POC (particulate organic carbon) in SPM (suspended particulate matter), nutrients, and DOC (dissolved organic carbon) ready to be transported to the sea. The annual water-sediment regulation scheme (WSRS), generally carried out in June and July since 2002 at the Xiaolangdi reservoir, induced pulsed changes in both water discharge and sediment contents downstream that destroyed the natural sediment-water balance, so that the chemical parameters of sediments (POC (%), POC/PN (particulate nitrogen), δ¹³C in POC, and δ¹⁵N in PN) at the lower reaches did not show clear seasonal variation patterns anymore. At the same time, however, concentrations of NO₃⁻, SiO₃²⁻, NO₂⁻, and DOC still maintained apparent seasonal variations. Concentrations of NO₃⁻, SiO₃²⁻, NH₄⁺, and NO₂⁻ as well as DOC displayed significantly decreasing trends after 2000, which were different from their decadal trends of increasing in the last century. These new trends, owing to the successful implementation of the environmental protection projects, as well as to the prolonged retention times of river waters after the constructions of a large number of reservoirs over the river basin, reflected the profound transformation and evolution of the Huanghe River aquatic ecosystems just occurring recently.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"251 ","pages":"Article 104111"},"PeriodicalIF":2.7,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144694313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamics of the Iokanga River plume according to SAR and optical satellite data","authors":"Aleksandr Konik ,&nbsp;Alexander Osadchiev","doi":"10.1016/j.jmarsys.2025.104093","DOIUrl":"10.1016/j.jmarsys.2025.104093","url":null,"abstract":"<div><div>The Iokanga River is one of the largest rivers of the Kola Peninsula, discharging into the southwestern part of the Barents Sea and the northern part of the White Sea. The outflows from the Iokanga River and other regional rivers form a freshened coastal water mass, which extends eastward as the Coastal Murmansk Current. However, the dynamics and variability of small river plumes, which represent a transitional form between river discharge and the coastal water mass, remain practically unexplored in this region. In this study, based on high-resolution synthetic aperture radar (SAR) and optical images, the spatial characteristics of the Iokanga plume were examined and its dynamics were analyzed during the ice-free period. The study provides an assessment of external hydrometeorological factors and their contribution to the variability of the plume positions on various time scales. Notably, a key contribution of tidal currents to the formation of the intra-daily variability of the plume was established, which is nontypical for the majority of river plumes in the Arctic Ocean. The current work also describes the main characteristics of submesoscale eddies in the Iokanga plume and analyzes the mechanisms of their formation. The obtained results are crucial for understanding the process of coastal water mass formation in the southwestern Barents Sea and for identifying potential pathways for river-borne contaminant spread. From a methodological perspective, this work may be valuable for studying the characteristics of small river plumes using SAR and optical satellite data in coastal regions, which are poorly covered by in situ measurements.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"250 ","pages":"Article 104093"},"PeriodicalIF":2.7,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144522502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mesoscale assemblages of fish and megainvertebrates as evidence of benthiscapes on continental shelves","authors":"Thomas Outrequin ,&nbsp;Hervé Le Bris ,&nbsp;Jacques Grall ,&nbsp;Pascal Laffargue","doi":"10.1016/j.jmarsys.2025.104088","DOIUrl":"10.1016/j.jmarsys.2025.104088","url":null,"abstract":"<div><div>Despite the relatively small proportion of ocean surface they represent, continental shelf ecosystems are among the most productive in the world. Located at the interface between terrestrial and marine environments, these habitats are structured by strong environmental forcings, especially on the sea bottom. A clear understanding of the spatial distribution of these habitats, along with knowledge on the composition and functioning of their associated communities, is essential for fisheries management and ecosystem conservation. Here, we used data from yearly EVHOE otter trawl surveys (2008–2020) to characterize the spatial structuration of benthic communities of the entire continental shelf of the Bay of Biscay (France), and to investigate the potential environmental drivers of these patterns. Two separate biological components were studied: epibenthic megainvertebrates and bentho-demersal fish. Clustering analyses identified seven assemblages from species composition of stations. Each assemblage was denominated according to its geographical location. We detected a strong correlation between the spatial organization of the different assemblages identified for fish and megainvertebrates, providing evidence for broad-scale spatial structuration of benthic habitats—benthiscapes—in this shelf ecosystem. The most influential environmental variables were identified as bottom temperature, sediment type, and primary production. Patterns in certain structural parameters, such as biomass, revealed possible spatial differences in ecological functioning. For example, we observed a drop in biomass from the coast to the central part of the shelf, followed by an increase in biomass near the edge of the Armorican shelf. These patterns reflect major large-scale processes (river inputs versus shelf-break upwelling) structuring the entire Bay of Biscay ecosystem. A comparative analysis revealed that the biological features and functioning observed in this study are shared with other European continental shelves. In addition to improving our knowledge of benthic environments, studies such as this one can promote improvements in ecosystem-based management and marine spatial planning of a fast-changing ecosystem under multiple anthropogenic stresses.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"250 ","pages":"Article 104088"},"PeriodicalIF":2.7,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144502482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}