Estuarine Coastal and Shelf Science最新文献

{"title":"Distribution of benthic communities in a hypertidal estuary: Mapping potential prey resources for juvenile common sole Solea solea","authors":"Marion Lefebvre du Prey ,&nbsp;Ross Griffin ,&nbsp;James E. Stewart ,&nbsp;Emma Sheehan ,&nbsp;Anna Sturrock ,&nbsp;Benjamin J. Ciotti","doi":"10.1016/j.ecss.2025.109660","DOIUrl":"10.1016/j.ecss.2025.109660","url":null,"abstract":"<div><div>Benthic macrofauna of the intertidal zone in the Severn Estuary was characterised, and its implications for potential food availability for juvenile common sole (<em>Solea solea</em>), a commercially valuable species, were discussed. Although the Severn Estuary supports fish assemblages of conservation interest, its role in sustaining juvenile fish populations remains poorly understood. Identifying high-quality habitats for juvenile sole is essential for effective conservation planning and ecosystem-based management. Direct measurements of habitat quality, such as fish abundance, growth, and contributions to adult population are challenging to obtain in hypertidal, complex systems like the Severn Estuary. Therefore, existing high-resolution benthic datasets were used to provide a first-order approximation of habitat quality and establish a baseline for future investigations. Because food availability strongly influences fish growth, distribution, and survival, examining prey assemblages offers valuable ecological insight. Benthic community structure was described across the intertidal area and statistically related to environmental variables, with a particular focus on habitat type. Results indicate that Habitats of Conservation Interest (seagrass beds and <em>Sabellaria alveolata</em> reefs) support greater potential prey diversity, whereas mudflats host higher potential prey biomass. Given the extensive mudflats in the estuary and the abundance of key sole prey taxa they harbour, intertidal mudflats are likely important feeding grounds for juvenile common sole. This study represents the most comprehensive invertebrate survey of the area, providing crucial insights into potential prey availability for juvenile common sole. These findings can inform conservation and management strategies in the Severn Estuary.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"329 ","pages":"Article 109660"},"PeriodicalIF":2.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145737154","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":"Environmental and human impacts on fish assemblages in shallow bay areas of South-eastern Brazil","authors":"Wagner Uehara,&nbsp;Gustavo Henrique Soares Guedes,&nbsp;Marcia Cristina Costa de Azevedo,&nbsp;Victória de Jesus Souza,&nbsp;Francisco Gerson Araújo","doi":"10.1016/j.ecss.2025.109683","DOIUrl":"10.1016/j.ecss.2025.109683","url":null,"abstract":"<div><div>Environmental and human influences strongly shape fish assemblages in coastal marine ecosystems, yet their combined effects remain unclear. This study examines how anthropogenic activities and environmental variables (e.g., salinity, substrate roughness, beach dimensions, and water renewal) influence fish assemblage descriptors (species composition, abundance, richness, taxonomic diversity, and trophic guilds) in two bays, two types of sandy beaches (continental vs. insular), across two seasons (winter and summer) in southeastern Brazil. We hypothesized that (H1) fish assemblage characteristics vary between bays, beach types, and seasons due to differing environmental features, and (H2) ecological and anthropogenic factors have distinct effects on assemblage descriptors. We conducted 312 beach-seine samples and analyzed the data using PERMANOVA and Generalized Additive Mixed Models (GAMMs). Results show that fish assemblages differ significantly by bay, beach type, and season, with significant interactions between bays and beach types, supporting H1. Fish abundance and richness, as well as the abundance of benthivorous and planktivorous species, were higher on continental beaches. Environmental factors differentially influenced assemblage descriptors, supporting H2. For example, human impact (Human Footprint Index) was a major predictor of fish abundance, richness, and specific trophic guilds (e.g., planktivores and opportunists). Species richness peaked at intermediate salinity (∼30), substrate roughness positively affected planktivores but negatively affected benthivorous, beach length was negatively associated with total abundance and opportunistic species, and depth negatively correlated with taxonomic distinctness and benthivore abundance. These findings highlight the role of local environmental conditions in structuring fish assemblages and emphasize the need for conservation strategies that preserve habitat complexity in tropical marine ecosystems.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"329 ","pages":"Article 109683"},"PeriodicalIF":2.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145839946","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":"An invader chronicles: local ecological niche of Mnemiopsis leidyi in the Venice Lagoon","authors":"F. Piccardi ,&nbsp;S. Girardello ,&nbsp;S.M. Bussard ,&nbsp;V. Tirelli ,&nbsp;D. Borme ,&nbsp;A. Barausse ,&nbsp;C. Mazzoldi","doi":"10.1016/j.ecss.2025.109678","DOIUrl":"10.1016/j.ecss.2025.109678","url":null,"abstract":"<div><div>The invasive ctenophore <em>Mnemiopsis leidyi</em> poses ecological threats in invaded coastal ecosystems such as the Venice Lagoon due to its high fecundity and adaptability to various climates. Although its dynamics have been studied in other regions, information from Mediterranean lagoons, which are characterized by strong spatial and seasonal variability in environmental conditions, remains limited. This study provides the first integrated field and laboratory investigation of the species’ ecological niche in the Venice Lagoon, combining two years of spatial distribution monitoring with controlled experiments to define key environmental thresholds for its survival. Our results shows that the species displays a seasonal pattern, blooming in late spring and late summer-early autumn, likely related to warmer temperatures and optimal salinity; indeed, its abundance positively correlated with water temperature and salinity. The controlled laboratory results integrated field observations by showing that <em>M. leidyi</em> can survive across a wide range of temperatures (10–32 °C) and salinities (10–34), but the extreme conditions of this range, such as very high temperatures (32 °C) or low salinity (10), markedly reduced its survival. By integrating <em>in situ</em> observations with experimentally estimated thresholds, this study provides novel insights into the ecological niche of <em>M. leidyi</em> in a Mediterranean lagoon. The results suggest that ongoing climate change may shift the lagoon towards more favorable conditions for this species, potentially intensifying bloom events and their cascading ecological impacts. These findings highlight the need for targeted monitoring and adaptive management to mitigate the ecological and socio-economic consequences of <em>M. leidyi</em> expansion.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"329 ","pages":"Article 109678"},"PeriodicalIF":2.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145840008","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":"Wolf Spiders as ecological models and disturbance indicator species on sandy beaches: A case study from southeastern Brazil","authors":"Igor David da Costa ,&nbsp;Vitor Figueira Arueira ,&nbsp;Leticia Arcelino ,&nbsp;Natalia Neto dos Santos Nunes ,&nbsp;Eduardo Bulhões ,&nbsp;Ilana Rosental Zalmon ,&nbsp;Leonardo Lopes Costa","doi":"10.1016/j.ecss.2025.109662","DOIUrl":"10.1016/j.ecss.2025.109662","url":null,"abstract":"<div><div>Spiders are one of the least studied groups in sandy beach ecosystems, despite being an important component of these habitats. As a result, their potential as model species for ecological studies and indicator of human impacts on beaches remains largely underexplored. This study investigated the influence of local and landscape factors on burrow abundance of the wolf spider <em>Allocosa brasiliensis</em> across 30 sandy beach sectors in southeastern Brazil. We tested the Cumulative Harshness Hypothesis (CHH), which predicts that human disturbances amplify the impact of natural beach harshness. We surveyed 10 beach sectors from each morphodynamic type, performing standardized counts of wolf spider burrows in the supralittoral zone near coastal vegetation margin. Simultaneously, we collected sediment samples from the retention zone and supralittoral for granulometric analysis, measured the beach slope, captured potential prey, and georeferenced the coastline to obtain satellite-based data on urbanization levels, vegetation cover, proximity to rivers, and erosion rates. The wolf spider was more abundant on dissipative beaches compared to intermediate and reflective morphodynamic types. Multiple regression analyses revealed that higher burrow abundance was associated with smaller sediment grain size in the supralittoral zone, besides with relatively stable coastal displacement, lower urbanization levels, greater vegetation cover, and also higher abundance of potential prey. The CHH was not supported, as the species responded similarly to urbanization across all morphodynamic types according to generalized linear models. Therefore, our results suggest that the wolf spider can be used as an indicator species of human disturbances across different beach morphodynamic types.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"329 ","pages":"Article 109662"},"PeriodicalIF":2.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145737702","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":"Exchange flow structure at two inlets of a multiple-inlet subtropical estuary","authors":"Maria F. Gastelu-Barcena ,&nbsp;Jorge A. Laurel-Castillo ,&nbsp;Maitane Olabarrieta ,&nbsp;Christine Angelini ,&nbsp;David Fugate ,&nbsp;Arnoldo Valle-Levinson","doi":"10.1016/j.ecss.2025.109649","DOIUrl":"10.1016/j.ecss.2025.109649","url":null,"abstract":"<div><div>This study seeks to advance understanding of residual, or subtidal, exchange flow structures at different inlets of a multiple-inlet estuary. For this purpose, the study used towed Acoustic Doppler Current Profiler (ADCP) measurements and hydrographic profiles during one diurnal tidal cycle. The spatial structure of ocean-estuary exchange was observed at the two main inlets of the Charlotte Harbor estuary, Florida, which is influenced by well-defined subtropical seasons: wet and dry. The &lt;6 m deep San Carlos Bay inlet was sampled in late August during the wet season and the &lt;16 m deep Boca Grande Pass was sampled in March during the dry season. Results revealed distinct subtidal flow distributions at the two inlets: vertically sheared exchange flows in San Carlos Bay, and laterally sheared exchange flows in Boca Grande Pass. Non-dimensional densimetric tidal Froude and Ekman numbers, as well as analytical model results, suggested the main drivers of the contrasting flow patterns. Vertically sheared flows at San Carlos Bay displayed relatively small densimetric tidal Froude and Ekman numbers, associated with density gradients as the main driving agent. Boca Grande Pass showed relatively large tidal Froude number because of the influence of tidal stresses, and relatively large Ekman number caused by friction. These differences were attributed to the contrasting characteristics of the two inlets, including their bathymetry, tidal forcing and river discharge influence. Such differences are explained by the non-dimensional numbers, which should be applicable to other inlets forced by tides and density gradients.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"329 ","pages":"Article 109649"},"PeriodicalIF":2.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145737247","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":"Lipid unsaturation correlates with population dynamics of the copepod Platychelipus littoralis in intertidal mudflats","authors":"Iene Herman ,&nbsp;Bram Martin ,&nbsp;Julieta Vigliano Relva,&nbsp;Anna-Maria Vafeiadou,&nbsp;Marleen De Troch","doi":"10.1016/j.ecss.2025.109691","DOIUrl":"10.1016/j.ecss.2025.109691","url":null,"abstract":"<div><div>This study provides a one-year baseline dataset for the copepod species <em>Platychelipus littoralis</em>, one of the most abundant benthic copepods inhabiting intertidal mudflats in Western Europe. As a key member of the meiofaunal community, <em>P. littoralis</em> plays an essential role in the estuarine and coastal mudflat ecosystems, particularly through its interactions with microphytobenthos at the base of the food web. This study aims to track seasonal dynamics in the intertidal copepod community and identify key drivers of population abundance for this harpacticoid species. Absolute fatty acid concentrations and unsaturation of <em>P. littoralis</em> were maximal in winter and lowest in summer. The copepods’ fatty acids match the homeoviscous thermal adaptation response of diatoms as their main food source. Rather unusual for copepods, <em>P. littoralis</em> primarily reproduced in winter, with the number of egg-carrying females doubling and egg sacs being 50 % larger compared to summer. We hypothesized that this reproductive strategy maximalizes egg production by aligning with the seasonal availability of diatom-derived polyunsaturated fatty acids (PUFAs) during the colder winter months. During winter diatom blooms, <em>P. littoralis</em> reached up to 25 % of total copepod population abundance, with local variability driven by the mudflat patchiness. Its reproductive success appears to be indirectly temperature-dependent, suggesting a high vulnerability to rising seawater temperatures predicted under climate change scenarios. Given its large geographical range, its temperature sensitivity as a winter breeder, and close association with diatom fatty acid unsaturation, the species shows strong potential as an indicator species for climate change monitoring.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"329 ","pages":"Article 109691"},"PeriodicalIF":2.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145884470","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":"Deciphering gametogenic strategies of Perna viridis in a tropical estuarine ecosystem: Mechanistic links between fatty acid allocation and environmental synchrony","authors":"Md Nayeem Hossain ,&nbsp;Afshana Ferdous ,&nbsp;Israt Jahan ,&nbsp;Md Moshiur Rahman ,&nbsp;Md Asaduzzaman","doi":"10.1016/j.ecss.2025.109687","DOIUrl":"10.1016/j.ecss.2025.109687","url":null,"abstract":"<div><div>Understanding how monsoon-driven environmental variability and trophic interactions regulate fatty acid dynamics during gametogenesis is fundamental to linking marine bivalve reproductive strategies with ecosystem processes in coastal systems. This study assessed the gametogenic strategies of the green mussel, <em>Perna viridis</em>, through an integrative analysis of fatty acid dynamics between gonadal and somatic tissues, revealing the critical roles of trophic interactions and environmental factors in shaping its reproductive cycle in the southeastern Bay of Bengal. Fatty acid profiling demonstrated that polyunsaturated fatty acids (PUFAs), particularly eicosapentaenoic acid (C20:5n-3) and docosahexaenoic acid (C22:6n-3), accumulated substantially in body and gonad during developing and mature stages, whereas saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs) predominated in spawning stage. Transitional developmental stages exhibited initiation of lipid mobilization from body to gonad, while the spent stage showed diminished MUFAs and SFAs reserve, indicating expenditure of energy for somatic recovery. Multivariate analyses (PCA, PLS-DA) clearly separated gonadal and body tissues, with VIP scores highlighting C20:5n-3, C22:6n-3, and n-3 PUFAs as key discriminatory markers of reproductive activity. Volcano plots and heatmap analyses further confirmed dynamic shifts in lipid metabolism, with gonads consistently enriched in long-chain PUFAs relative to body tissues. Correlation analyses demonstrated strong synchrony between gonadal and somatic fatty acids, yet trophic linkages indicated that mussels derived essential fatty acids primarily from Bacillariophyceae, Chlorophyceae, Cyanophyceae, Pyrrophyceae, and zooplankton during favorable conditions, rather than depending on somatic reserves. This pattern reflects an opportunistic energy allocation strategy, whereby immediate dietary inputs fuel gamete maturation, contrasting with conservative schemes reported in many other bivalves. Collectively, these results highlight that reproductive success in <em>P. viridis</em> is shaped by a dynamic interplay between food availability, environmental variability, and fatty acids allocation, with opportunistic strategies ensuring reproductive efficiency under fluctuating environmental conditions. Overall, this work deepens mechanistic insights into the remarkable adaptability of reproductive strategies of green mussels to monsoon-driven stress in tropical coastal ecosystems, highlighting their resilience under fluctuating environmental conditions.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"329 ","pages":"Article 109687"},"PeriodicalIF":2.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145884471","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":"Climatic forcing modulates non-stationary environmental synchrony in shellfish production regions","authors":"Carlos Lara ,&nbsp;Richard Muñoz ,&nbsp;Sebastián I. Vásquez ,&nbsp;Felipe I. Torres ,&nbsp;Amalia M.S. Detoni ,&nbsp;Bernardo R. Broitman ,&nbsp;Bernard Cazelles","doi":"10.1016/j.ecss.2025.109605","DOIUrl":"10.1016/j.ecss.2025.109605","url":null,"abstract":"<div><div>Coupled fluctuations between ecological and environmental processes — i.e., synchrony — have been documented in marine ecosystems across multiple spatial and temporal scales. To investigate multiscale synchrony, we applied Wavelet Coherence (WC) and Partial Wavelet Coherence (PWC) analyses to disentangle nonstationary associations between local and regional environmental variables that are critical for shellfish aquaculture along the southeastern Pacific. Specifically, we examined and controlled the effects of local associations between sea surface temperature (<span><math><mrow><mi>S</mi><mi>S</mi><mi>T</mi></mrow></math></span>) and shellfish food supply, represented by normalized fluorescence line height (<span><math><mrow><mi>n</mi><mi>F</mi><mi>L</mi><mi>H</mi></mrow></math></span>), in relation to the regional El Niño–Southern Oscillation (<span><math><mrow><mi>E</mi><mi>N</mi><mi>S</mi><mi>O</mi></mrow></math></span>). Using MODIS-Aqua satellite time series (2003–2022) and the Multivariate ENSO Index (<span><math><mrow><mi>M</mi><mi>E</mi><mi>I</mi></mrow></math></span>), we assessed temporal changes in the coupling between <span><math><mrow><mi>S</mi><mi>S</mi><mi>T</mi></mrow></math></span> and <span><math><mrow><mi>n</mi><mi>F</mi><mi>L</mi><mi>H</mi></mrow></math></span> in two bivalve aquaculture regions: Tongoy Bay (north-central Chile) and northern Chiloé (southern Chile). Our analyses revealed that <span><math><mrow><mi>S</mi><mi>S</mi><mi>T</mi></mrow></math></span> exhibited a stationary annual cycle explaining over 95% of total variance, while <span><math><mrow><mi>n</mi><mi>F</mi><mi>L</mi><mi>H</mi></mrow></math></span> showed a dominant annual mode accounting for more than 60% of variance. However, the second mode of <span><math><mrow><mi>n</mi><mi>F</mi><mi>L</mi><mi>H</mi></mrow></math></span> in both Tongoy Bay and northern Chiloé reflected the influence of local drivers — such as freshwater discharge events — that were not synchronized with the dominant pattern. PWC analyses identified significant intra- and interannual synchrony between <span><math><mrow><mi>n</mi><mi>F</mi><mi>L</mi><mi>H</mi></mrow></math></span> and <span><math><mrow><mi>E</mi><mi>N</mi><mi>S</mi><mi>O</mi></mrow></math></span> within the 1.5–2.5 yr and 3–5 yr bands, after removing the influence of <span><math><mrow><mi>S</mi><mi>S</mi><mi>T</mi></mrow></math></span>. These results demonstrate that large-scale climatic forcing modulates local environmental synchrony through differential regional coupling strengths. Consequently, the predictability of environmental conditions relevant to shellfish aquaculture in both regions appears to be strongly constrained by <span><math><mrow><mi>E</mi><mi>N</mi><mi>S</mi><mi>O</mi></mrow></math></span>-driven variability operating across multiple temporal scales.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"329 ","pages":"Article 109605"},"PeriodicalIF":2.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145685006","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":"Alternate rotating layered circulation in response to extrinsic and intrinsic forcing in the Japan sea","authors":"Junlu Li ,&nbsp;Jianping Gan","doi":"10.1016/j.ecss.2025.109650","DOIUrl":"10.1016/j.ecss.2025.109650","url":null,"abstract":"<div><div>The three-dimensional circulation in the Japan Sea (JS) plays an important role in its water mass and biogeochemical substances exchange with neighboring oceans. However, characterizing the spatiotemporal circulation pattern in the JS, and diagnosing its complex forcing mechanism between intrinsic flow-topography interaction and extrinsic flux through the straits connected with adjacent seas remain challenge. Combined observations with numerical modeling and a novel Stokes-based layer-integrated vorticity equation (LIVE) dynamics, we discovered a three-layer circulation with alternating cyclonic, anti-cyclonic, and cyclonic circulation in the upper (0–150 m), middle (150–250 m), and bottom (&gt;250 m) layers in the JS, respectively. The strong cyclonic and weak anti-cyclonic circulations in the upper and middle layers show similar seasonal phase: the domain-integrated vorticity anomaly is positive during winter and negative from summer to early autumn. In contrast, cyclonic circulation in the bottom layer remains relatively stable throughout the year. We diagnosed that besides vorticity input from wind stress curl in the upper layer, the lateral planetary vorticity fluxes from inflow/outflow through the straits surrounding the JS lead to vortex stretching in all layers and extrinsically control the structure of the layered circulation. The joint effects of baroclinicity and relief (JEBAR) arising from flow–topography interaction is an intrinsic dynamic response to the extrinsic forcing and dynamically shapes the layered circulation. Based on Stokes circulation theorem, this study characterizes the layered circulation pattern, and based on LIVE dynamics, effectively identifies intrinsic and extrinsic forcing mechanisms for the layered circulation in the JS and other marginal seas.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"329 ","pages":"Article 109650"},"PeriodicalIF":2.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145685002","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":"Dual drivers of Ulva blooms in Jeju Island: Submarine groundwater discharge as nutrient source and aquaculture effluent as ammonium trigger","authors":"Yongwon Kim,&nbsp;Tae-Hoon Kim,&nbsp;Min-young Lee","doi":"10.1016/j.ecss.2025.109644","DOIUrl":"10.1016/j.ecss.2025.109644","url":null,"abstract":"<div><div>Green tides caused by <em>Ulva</em> spp. pose a significant threat to coastal ecosystems. This study examined the distinct roles of two nutrient pathways—submarine groundwater discharge (SGD) and onshore aquaculture effluent—in fueling recurrent <em>Ulva</em> blooms in Bangdu Bay, Jeju Island. In winter 2023, a non-bloom period, we analyzed concentrations of nutrients (DIN, DIP, DSi, and NH₄⁺), dissolved organic carbon (DOC), and particulate organic carbon (POC) in SGD, aquaculture-affected seawater, and within the bay. A mass balance model estimated total SGD flux of 3.1 × 10⁵ m³ day⁻¹, confirming SGD as the dominant nutrient source, supplying 93 % of the total DIN. The exceptionally high POC concentration in SGD (mean 426 μM) suggests a potential internal recycling mechanism, where <em>Ulva</em>-derived organic matter is recirculated into the bay. In contrast, although aquaculture contributed a smaller portion of DIN, its NH₄⁺ flux was 2.7 times higher than that from SGD. This identifies aquaculture effluent as a critical “trigger,” supplying bioavailable nitrogen that initiates rapid seasonal growth. The non-conservative behaviors of DIP, NH₄⁺ and organic carbon indicate that the bloom actively drives the bay's biogeochemical cycles. In conclusion, the bloom is sustained by a complex mechanism involving two key drivers: (1) persistent, broad-scale supply of nutrients and recycled POC via SGD, and (2) concentrated, high-flux input of NH₄⁺ from aquaculture. These findings highlight the need for a dual-management strategy targeting both chronic background loading and acute localized triggers.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"329 ","pages":"Article 109644"},"PeriodicalIF":2.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145685000","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}