Continental Shelf Research最新文献

{"title":"Early Pleistocene fossil seagrass assemblages on Rhodes Island – a proof of allochthonous origin","authors":"Katarína Holcová ,&nbsp;Martina Havelcová ,&nbsp;Sanah Shaikh ,&nbsp;Markéta Chroustová ,&nbsp;Katarína Šarinová ,&nbsp;Filip Scheiner ,&nbsp;Petr Kraft ,&nbsp;Ivana Sýkorová ,&nbsp;Rastislav Milovský","doi":"10.1016/j.csr.2025.105594","DOIUrl":"10.1016/j.csr.2025.105594","url":null,"abstract":"<div><div>This study investigates fossil seagrass accumulations in the Pliocene–Pleistocene Kritika Formation on Rhodes Island using geochemical, organic petrology and palaeobiological proxies. The studied section can be correlated with the lower Calabrian (1.7–1.6 Ma). Inorganic geochemistry revealed fluctuations between freshwater and marine environments, suggesting a dynamic estuarine environment, as supported by the analysed δ¹³C_org values, which varied from −25.0 to −23.5 ‰. High concentrations of terrestrial organic matter indicate significant riverine input to the coastal area under warm and humid climatic conditions. Further, elevated Ni (720–1100 ppm) and Co (41–60 ppm) concentrations in the sediments indicate a basic/ultrabasic (ophiolitic) sediment source in the catchment area. The absence of marine organisms in these accumulations and reduced estuarine salinity suggest that <em>Posidonia</em> leaves were transported within the estuary rather than deposited <em>in situ</em>. Organic geochemical analyses revealed minor peaks of submerged plant-specific <em>n</em>-alkanes (C₂₁, C₂₃, C₂₅) similar to modern dead <em>Posidonia</em> accumulations. Abundant short even <em>n</em>-alkanes (C₁₆, C₁₈) associated with heterotrophic bacteria and fungi are also present, indicating microbial decomposition. Identical geochemical signatures in samples without <em>Posidonia</em> body fossils confirmed the presence of amorphous organic matter of seagrass origin, further demonstrating that organic geochemical proxies can identify ancient seagrass meadows even in the absence of body fossils.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"296 ","pages":"Article 105594"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145418562","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":"Lithological and geochemical differentiations in an urbanized, shallow marine cold-seep environment. The case of Patras Gulf active pockmark field","authors":"Spyros Sergiou,&nbsp;Dimitra Ntrouva,&nbsp;Maria Geraga,&nbsp;Dimitris Christodoulou,&nbsp;George Papatheodorou","doi":"10.1016/j.csr.2025.105583","DOIUrl":"10.1016/j.csr.2025.105583","url":null,"abstract":"<div><div>The Patras Gulf Pockmark Field (PGPF), located in a shallow, tectonically active marine basin in western Greece, offers a unique setting for studying lithological and geochemical variability in an urban-influenced cold-seep environment. Here we examine nine short sediment cores (∼30 cm) collected from both within pockmarks and the surrounding seafloor to assess sediment texture, elemental composition, and anthropogenic impacts. We find that pockmark sediments are finer-grained, better-sorted, less bioclastic, more organic-rich, and higher in trace metals loads compared to the surrounding seafloor. The sedimentary, geochemical, and hydrodynamic processes within the pockmarks follow the pockmark morphology; the larger the pockmark is, the more terrigenous, fine-grained, and metal-enriched the sediment is, and less oxygenation characterizes the bottom waters. Multivariate factor analysis identified five dominant geochemical processes. Factors 1 and 2, prevailing outside the pockmarks, reflect clay–metal sorption processes and the anticorrelation between bioclastic material and fine-grained terrigenous inputs. Within pockmarks, Factor 3 indicates anthropogenic sources of Ag, Hg, and Zn through organic carbon–metal sequestration, especially in the southern sector of PGPF, influenced by Glafkos River discharges. Factor 4 reflects localized contamination by Zr, Ta, and Nb, while Factor 5 captures sulfidic, low-oxygen conditions linked to redox dynamics. Despite documented fluid escape activity, no clear imprints of active seepage were observed in the studied pockmark sediments. These findings emphasize the dual control of geomorphology and anthropogenic forcing on geochemical processes in shallow marine cold-seep environments, with implications for trace metal mobility, sediment trapping efficiency, and environmental monitoring in similar settings.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"296 ","pages":"Article 105583"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145247906","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":"Ecosystem function: Trait diversity, bioturbation, and bio-irrigation potentials of macrobenthic invertebrate communities in the Red Sea","authors":"Seerangan Manokaran ,&nbsp;Thadickal V. Joydas ,&nbsp;Paravanparambil Rajakumar Jayachandran ,&nbsp;Jayanath Gopi ,&nbsp;Omer Reshi ,&nbsp;Karuppasamy P. Manikandan ,&nbsp;Mohamed A. Qurban","doi":"10.1016/j.csr.2025.105593","DOIUrl":"10.1016/j.csr.2025.105593","url":null,"abstract":"<div><div>The ecosystem functions of macrobenthic invertebrates were studied in the Red Sea. In total, 193 taxa were recorded. The functional traits of biomass (B) and density (D), such as infauna with internal irrigation (B - 53.4 %), blind-ended burrows, no burrow systems (D - 44.5 %), surface filter (B - 41.5 %), and surface deposit feeders (D - 50.8 %) were dominant attributes with significant regional and depth differences. However, irrigation depth 0 to 2 – 5 cm (B - 50 %, D - 45 %); movements through the sediment matrix mobility pattern (B - 68.3 %, D - 47.2 %), and reworking superficial modifiers (B - 54.2 %, D - 45.2 %) also significantly dominated. The functional individuals, biomass, richness, density, and diversity were 11 ± 1 (Mean ± SE) species m⁻², 1.25 ± 0.26 g m⁻², 1.70 ± 0.13 Fd’, 361 ± 57 ind. m⁻², and 2.76 ± 0.11FH' (log²). These indices decreased with increased depth and were higher in the north compared to the central region. The composition of bioturbation potential community index (BPc) and bio-irrigation potential community index (IPc) values was significantly <em>(P &lt; 0.05)</em> higher in the north (29.46 ± 5.48, and 42.12 ± 10.33) and shallower (55.32 ± 12.79, and 83.76 ± 26.93) depth zones. The taxa <em>Aglaophamus dibranchis,</em> holothuria, sand dollar, and <em>Glycinde</em> sp.1 were responsible for higher BPc, and the taxa sand dollar, Spionidae indet. <em>Notomastus latericeus</em>, <em>Glycinde</em> sp.1, and <em>Prionospio</em> spp. contributed higher to IPc. The environmental variables MGS, silt/clay, depth, latitude (region), As, and Fe influenced functional density (<em>P = 0.191</em>) and biomass (<em>P = 0.182</em>), and MGS, depth, latitude, As, Mn, and Pb also influenced bioturbation (<em>P = 0.224</em>) and bio-irrigation (<em>P = 0.218</em>) of the macrobenthic community. Generally, the functional attributes influence deep-sea nutrient cycling by enhancing benthic and pelagic coupling processes on the Red Sea coast, particularly in relation to coastal developmental activities.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"296 ","pages":"Article 105593"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145467271","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":"Elevated meroplankton abundance in surface slicks during internal wave forcing at three coastal sites in Mexico","authors":"Lydia B. Ladah ,&nbsp;Andrea Lievana Mactavish ,&nbsp;María del Refugio Barba López ,&nbsp;James J. Leichter ,&nbsp;Fabian J. Tapia ,&nbsp;Anatoliy Filonov","doi":"10.1016/j.csr.2025.105599","DOIUrl":"10.1016/j.csr.2025.105599","url":null,"abstract":"<div><div>The supply of meroplanktonic larvae to coastal habitats by physical transport mechanisms is important for the persistence of benthic marine invertebrate populations. Larvae can accumulate in convergent bands that are often visible as smooth surface slicks in areas where surfactants reduce capillary waves. Slicks can form above passing troughs of internal waves, which occur on most coasts during stratified periods. In this study, during periods of strong internal wave forcing under spring tide conditions in three bays along the Mexican coastline, we sampled high-frequency (f ≥ 1 cycle h⁻¹) changes in the abundance of marine meroplankton. Concurrently, we recorded visual observations of surface slicks and measured physical conditions in the water column (i.e., temperature and currents). Surface slicks were observed at all three sites, with over 70% occurring at times theoretically predicted from current flows. The slick periods showed warmer temperatures or lower strain values, suggesting slicks may be associated with warm convergence zones. Chthamaloid cyprids and mussel veligers were the dominant meroplankton found, with their abundance being significantly greater (2–6 times) within slicks at all sites and a significant positive relationship with temperature found at 2 of the 3 sites. These results support the hypothesis that plankton accumulation does occur in visible surface slicks. We propose that the slicks measured in this study were related to internal wave convergence zones, meriting further exploration as important mechanisms of plankton accumulation.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"296 ","pages":"Article 105599"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145418561","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":"Corrigendum to “A three-year survey of hatched elasmobranch egg capsules on Santa Catarina Island, Southern Brazil” [Cont. Shelf Res. 293 (2025) 105528]","authors":"Carlos Alberto da Silva Junior ,&nbsp;Guilherme Burg Mayer ,&nbsp;Áthila Andrade Bertoncini ,&nbsp;Rafael de Lima ,&nbsp;Renato Hajenius Aché de Freitas","doi":"10.1016/j.csr.2025.105568","DOIUrl":"10.1016/j.csr.2025.105568","url":null,"abstract":"","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"296 ","pages":"Article 105568"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145617807","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":"Tidal and wind-driven spatiotemporal variability in the residual displacement and dispersion of Lagrangian particles in a system of intertidal basins","authors":"Jeancarlo M. Fajardo-Urbina ,&nbsp;Ulf Gräwe ,&nbsp;Herman J.H. Clercx ,&nbsp;Theo Gerkema ,&nbsp;Matias Duran-Matute","doi":"10.1016/j.csr.2025.105602","DOIUrl":"10.1016/j.csr.2025.105602","url":null,"abstract":"<div><div>This study identifies and quantifies the distinct contributions of wind and tides to the variability of Lagrangian residual transport in the Dutch Wadden Sea (DWS), a mesotidal system of interconnected tidal basins of high ecological relevance. A three-dimensional hydrodynamic model and offline particle tracking were used to simulate the transport of particle patches over individual tidal periods of the record 1980-2015 using depth-averaged currents. This transport was decomposed into the net displacement of their center of mass (advection) and the tidally averaged rate of change of dispersion from their center of mass (the dispersion coefficient). The results reveal that advection is predominantly wind-driven on the temporal scale of events. Strong winds from the North Sea aligned with the topographical orientation of the system trigger advection comparable to the width of the basins. Although the role of tides in advection is secondary, they induce residual circulation cells near the inlets, particularly evident during weak wind conditions. In contrast, dispersion is controlled by the tides and exhibits filamentous structures with large values around all the DWS inlets. The strength of these structures has a linear correlation with the tidal amplitude, which is mainly modulated by the spring-neap cycle. However, the location of these structures changes predominantly from shallow areas surrounding the channels when particles are released at high tide to within the channels when released at low tide. These findings underscore the distinct separable roles of wind and tides in Lagrangian residual transport within event-driven, multi-inlet coastal systems such as the DWS.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"296 ","pages":"Article 105602"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145520172","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":"Carbon stocks on the intertidal seagrass meadow of the Indonesian Islands: Spatial and anthropogenic activities variability","authors":"Fery Kurniawan ,&nbsp;Agustin Rustam ,&nbsp;Robba Fahrisy Darus ,&nbsp;Fauziyah ,&nbsp;Almira Nadia Kusuma ,&nbsp;Muhammad Noval Alghifari ,&nbsp;Luky Adrianto ,&nbsp;Yonvitner","doi":"10.1016/j.csr.2025.105604","DOIUrl":"10.1016/j.csr.2025.105604","url":null,"abstract":"<div><div>Human activities significantly influence carbon sequestration and carbon stock in seagrass ecosystems; however, their impacts on small islands remain understudied. Based on this gap, this study quantified seagrass carbon stocks across Indonesian islands, examining spatial variability and anthropogenic pressures. Carbon stocks were measured using the Loss on Ignition (LOI) method. Results showed relatively high values, with biomass ranging from 0.65 to 11.25 tC ha⁻¹ (4.01 ± 2.84 tC ha⁻¹), sediment from 22.46 to 98.53 tC ha⁻¹ (52.77 ± 17.61 tC ha⁻¹), and total carbon from 22.70 to 98.53 tC ha⁻¹ (56.78 ± 20.45 tC ha⁻¹). Significant spatial differences were observed among islands and land-use categories, indicating that average or constant values cannot be reliably applied for national carbon estimates. Anthropogenic activities also had a marked effect, underscoring the need to integrate human impacts into management and conservation strategies. These findings provide essential baseline data for national carbon accounting while highlighting the ecological and climate importance of small-island seagrass ecosystems. Protecting and restoring seagrass meadows should be prioritized as a dual strategy for climate adaptation and biodiversity conservation.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"296 ","pages":"Article 105604"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145520170","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":"Assessing the potential of consumer-grade fish finders to improve coastal habitat mapping in data-poor areas","authors":"Pedro T. Gomes ,&nbsp;Renato Henriques ,&nbsp;Marcos Rubal ,&nbsp;Diana Azevedo ,&nbsp;Diego Carreira-Flores","doi":"10.1016/j.csr.2025.105590","DOIUrl":"10.1016/j.csr.2025.105590","url":null,"abstract":"<div><div>Geospatial information is fundamental for understanding marine biodiversity patterns, species distribution, and environmental change. However, traditional methods for obtaining high-resolution bathymetric data are expensive and time-consuming, limiting data availability and creating significant gaps, particularly in coastal zones. This study explores the potential of consumer-grade sonars (fish finders) as cost-effective tools to improve bathymetric maps and support habitat mapping along a coastal area in northern Portugal. We compared bathymetric data collected by consumer-grade devices with publicly available digital elevation models (DEM) from EMODNET and high-resolution, survey-grade multibeam sonar data from the APA COSMO project. Results revealed strong agreement between consumer-grade sonar data and EMODNET DEM, with substantial improvement in local detail and acceptable errors (RMSE and MAE low; Pearson correlation coefficients from 0.957 to 0.963). Comparisons with COSMO DEM also showed good coherence, highlighting a significant increase in detail proportional to sampling density, though still lacking the fine resolution provided by the professional-grade COSMO dataset. Despite inherent limitations in precision and depth range, consumer-grade sonars proved highly valuable, offering practical solutions for low-resource, small-scale projects, environmental monitoring, and ecological habitat mapping. This study supports integrating these affordable devices into marine research workflows, significantly enhancing bathymetric data availability and spatial resolution, especially where detailed professional data are unavailable or economically unfeasible.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"296 ","pages":"Article 105590"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145326452","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":"Across-shelf scale-selective separation of a quasi-geostrophic current and internal gravity waves off southeastern Hokkaido, Japan","authors":"Tatsuro Karaki ,&nbsp;Yukiko Taniuchi,&nbsp;Hiromi Kasai,&nbsp;Hiroshi Kuroda","doi":"10.1016/j.csr.2025.105606","DOIUrl":"10.1016/j.csr.2025.105606","url":null,"abstract":"<div><div>Interactions between oceanic mesoscale currents and inertia-gravity waves (IGWs) are thought to facilitate the energy transition toward submesoscale regimes. Such mesoscale–submesoscale transition processes involve unbalanced motions, such as the IGWs, making it difficult to distinguish between them in observational data. Using across-shelf scale-selective filters, we separated the IGWs from a quasi-geostrophic (QG) current, the Coastal Oyashio (CO), based on a CTD-measured hydrographic section with ∼2-km resolution across the Pacific shelf off southeast Hokkaido, Japan, and clarified the mesoscale–submesoscale transition processes in this IGW–QG coupled system. To determine the optimum smoothing scale <span><math><mrow><msub><mrow><mo>Δ</mo><mi>Y</mi></mrow><mi>o</mi></msub></mrow></math></span>, we formulated indices based on non-dimensional numbers such as the Rossby number <span><math><mrow><msub><mi>R</mi><mi>o</mi></msub></mrow></math></span> and the Richardson number <span><math><mrow><msub><mi>R</mi><mi>i</mi></msub></mrow></math></span>, calculated from the CTD-derived along-shelf baroclinic velocity. Applying a low-pass filter with <span><math><mrow><msub><mrow><mo>Δ</mo><mi>Y</mi></mrow><mi>o</mi></msub></mrow></math></span> to the in-situ density section, where <span><math><mrow><msub><mi>R</mi><mi>o</mi></msub></mrow></math></span> and <span><math><mrow><msubsup><mrow><mspace></mspace><mi>R</mi></mrow><mi>i</mi><mrow><mo>−</mo><mn>1</mn></mrow></msubsup></mrow></math></span> were of magnitude <em>O</em>(1), resulted in a smoothed section where both <span><math><mrow><msub><mi>R</mi><mi>o</mi></msub></mrow></math></span> and <span><math><mrow><msubsup><mi>R</mi><mi>i</mi><mrow><mo>−</mo><mn>1</mn></mrow></msubsup></mrow></math></span> were reduced to ∼<em>O</em>(0.1), with <span><math><mrow><msub><mi>R</mi><mi>o</mi></msub><mo>≈</mo><msubsup><mi>R</mi><mi>i</mi><mrow><mo>−</mo><mn>1</mn></mrow></msubsup></mrow></math></span>. The smoothed isopycnals were sloped over the Rossby radius of deformation <span><math><mrow><msub><mi>L</mi><mi>d</mi></msub></mrow></math></span>, consistent with the geostrophic adjustment theory. More quantitatively, the diagnosis yielded an optimal smoothing scale of <span><math><mrow><msub><mrow><mo>Δ</mo><mi>Y</mi></mrow><mi>o</mi></msub></mrow></math></span> = 6 km. The IGWs propagating along the subsurface pycnocline, characterized by <span><math><mrow><msub><mi>L</mi><mi>d</mi></msub><mo>≈</mo></mrow></math></span> 1 km (i.e., a wavelength around 6 km, <span><math><mrow><mn>2</mn><mi>π</mi><msub><mi>L</mi><mi>d</mi></msub></mrow></math></span>), were successfully separated from the baroclinic jet structure of the CO, which had <span><math><mrow><msub><mi>L</mi><mi>d</mi></msub><mo>≈</mo></mrow></math></span> 10 km. As a result, our observations revealed a hybrid of symmetric and gravitational instability associated with IGW-breaking near the core of the CO baroclinic jet.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"296 ","pages":"Article 105606"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145520169","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":"Impacts of stratified water column on summer phytoplankton community structure and dynamics in the East Sea, Korea","authors":"Bora Lee ,&nbsp;Chung Hyeon Lee ,&nbsp;Yun-Bae Kim ,&nbsp;Chang Hwan Kim ,&nbsp;Chan Hong Park ,&nbsp;Seung Ho Baek","doi":"10.1016/j.csr.2025.105592","DOIUrl":"10.1016/j.csr.2025.105592","url":null,"abstract":"<div><div>Summer stratification strongly regulates nutrient availability and phytoplankton productivity in the East Sea. We examined the combined influences of the East Korea Warm Current (EKWC) and stratification intensity on phytoplankton communities in the Ulleung Basin during four consecutive summers (2021–2024). Years of weak EKWC transport (2021, 2023; 0.1–0.3 m s⁻¹) coincided with restricted offshore dispersal of coastal production and lower surface chlorophyll <em>a</em> (Chl. <em>a</em>; mean 0.34 μg L⁻¹). In contrast, strong EKWC years (2022, 2024; 0.5–0.8 m s⁻¹) exhibited enhanced offshore dispersion and higher Chl. <em>a</em> (mean 0.79 μg L⁻¹). Intensified stratification produced sharp vertical gradients in temperature (24–29 °C at 0–30 m vs. 6–13 °C at 50–100 m), salinity (31.8–32.6 vs. 33.9–34.2), and nitrate (≤5 vs. 6–12 μM), and supported the formation of subsurface chlorophyll maxima (SCM) at 13–47 m, where light and residual nutrients intersected. Community composition displayed strong vertical partitioning: pico-phytoplankton dominated nutrient-depleted surface layers (mean 61 % of biomass), while diatoms prevailed in SCM layers (38–70 %). Dinoflagellates, including <em>Katodinium glaucum</em> and <em>Gyrodinium</em> spp., increased under stratified conditions, and cryptophytes became more abundant at depth. Overall, these results demonstrate that EKWC variability controls horizontal transport of phytoplankton biomass, while stratification governs vertical zonation and taxonomic composition. As sea surface warming intensifies summer stratification, these findings provide critical baseline data for ecosystem models predicting future shifts in nutrient cycling, productivity, and food web dynamics in the East Sea.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"296 ","pages":"Article 105592"},"PeriodicalIF":2.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145364471","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}