Continental Shelf Research最新文献

{"title":"Assessment of inorganic water quality in marine areas affected by an artificial beach nourishment: A case study in northeastern Brazil","authors":"Luiz Carlos Nunes da Silva ,&nbsp;Ravena Santiago Alves ,&nbsp;Isabelle de Oliveira Lima ,&nbsp;Francisco Pereira Marques Neto ,&nbsp;Guilherme Ribeiro de Melo ,&nbsp;Francisca Cintia Silva do Nascimento ,&nbsp;Bárbara Pereira Paiva ,&nbsp;Kamila Vieira de Mendonça ,&nbsp;Rivelino Martins Cavalcante ,&nbsp;Maria Ozilea Bezerra Menezes ,&nbsp;Michael Barbosa Viana","doi":"10.1016/j.csr.2025.105488","DOIUrl":"10.1016/j.csr.2025.105488","url":null,"abstract":"<div><div>This study examines the impact of an artificial beach nourishment project on seawater quality at two beaches in Fortaleza, Ceará, Brazil. The research was conducted between October 2019 and May 2022. Twenty-seven inorganic water quality parameters were analyzed in five phases: at the beginning, during execution and in three phases after completion of the works. The distribution of chemicals in the marine sediment was also analyzed. The water analysis showed that the average concentrations of four parameters were above the maximum permissible values (MPV) established by the Brazilian standard in at least one phase of the study. The fluoride concentration reached 2.4 mg/L, exceeding the MPV of 1.4 mg/L. Polyphosphates recorded a maximum value of 0.085 mg/L, exceeding the MPV of 0.031 mg/L, while hydrogen sulfide reached 0.0023 mg/L, exceeding the MPV of 0.0020 mg/L. Total residual chlorine showed average concentrations above the MPV of 0.01 mg/L in all phases of the study, with a maximum value of 0.64 mg/L. On the basis of this study, there is no concrete evidence that the concentrations above the MPV are due to the artificial beach nourishment, as these concentration peaks were not only observed in the samples taken during the execution phase of the work. Furthermore, no significant permanent changes in the physical and chemical properties of the water were detected after the end of the work. The statistical differences observed in the inorganic water quality parameters can be attributed to the marine dynamics in the region, such as strong currents, mixing of water masses and the tidal regime. In addition, the study area is influenced by various anthropogenic activities that can contribute significantly to these changes. The analysis of metals and nutrients in the sediment revealed concentrations below the limits established by the Brazilian standard.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"291 ","pages":"Article 105488"},"PeriodicalIF":2.1,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143934768","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":"Modelling intensity and frequency of seabed shear stress and sediment mobilization on the Canadian Pacific Shelf","authors":"M.Z. Li ,&nbsp;Y. Wu ,&nbsp;I. Fine ,&nbsp;P.F. Cummins","doi":"10.1016/j.csr.2025.105480","DOIUrl":"10.1016/j.csr.2025.105480","url":null,"abstract":"<div><div>Ocean surface waves and currents can interact to produce strong seabed shear stress and sediments mobilization affecting infrastructure safety and benthic habitat distribution. An accurate understanding of these processes is important to inform decisions taken to ensure sustainable development of the oceans. Modelled waves, tidal current and circulation current data for a 3-year period were used in a combined-flow sediment transport model to simulate the seabed shear stresses and the mobilization of observed sediments on the Pacific Shelf of Canada. The modelling results are presented and analyzed to update the framework of seabed disturbance and sediment mobility on the Pacific Shelf. The shelf is affected by strong waves and tidal currents. Maximum mean significant wave height over the modelled period can reach 3 m and mean near-bottom tidal currents reach up to 0.6 m s⁻¹. Our modelling results indicate that the mean wave and tidal current shear velocities reach the maximum values of 4 and 3 cm s⁻¹ respectively. Observed sediments on the Pacific Shelf can be mobilized by tidal currents at least once during the modelled 3-year period over 46 % of the shelf area while waves can mobilize sediments over 47 % of the shelf area suggesting nearly equal tidal and wave effects. Furthermore, waves and currents interact to cause enhanced combined wave-current shear velocities &gt;5 cm s⁻¹ that are capable of mobilizing sediments over 80 % of the shelf area, nearly double that due to tides or waves alone. Regionalization of disturbance types based on the spatial variation of the relative importance of component processes in mobilizing sediments, however, demonstrates that tide-dominant disturbance type accounts for 43 % of the shelf area while wave-dominant disturbance accounts for 32 % of the shelf area suggesting tidal disturbance is more important than waves on the Pacific Shelf. Mixed disturbance only occurs over a small 11 % of the shelf area. Universal indices of Seabed Disturbance (SDI) and Sediment Mobility (SMI) were applied to better quantify the exposure of the seabed to oceanographic processes and sediment mobility, incorporating both the magnitude and frequency of these processes. Strong casual correlation between modelled shear stress and observed grain sizes for a range of values and over widely distributed areas on the shelf suggests that sediments are largely in equilibrium with the present-day hydrodynamics on the Pacific Shelf of Canada. The spatial variation of modelled bed shear stress, its correlation with the observed grain size, and patterns of modelled sediment mobilization and disturbance types from our study support and potentially improve the surficial geology, morphology, and sedimentary process knowledge for several regions of the Pacific Shelf.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"291 ","pages":"Article 105480"},"PeriodicalIF":2.1,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144068083","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":"Escalating variability of daily sea temperature decreases phytoplankton spring blooms","authors":"Zixuan Sun ,&nbsp;Yan Du ,&nbsp;Dongdong Xiang","doi":"10.1016/j.csr.2025.105479","DOIUrl":"10.1016/j.csr.2025.105479","url":null,"abstract":"<div><div>Increases in sea surface temperature (SST) and its variability (SSTV) in the context of climate change have a great impact on marine phytoplankton productivity, but their combined effects on phytoplankton biomass, especially at a daily scale, have been poorly assessed. Here, we used an extended autoregressive (EAR) model to assess the different roles of SST and SSTV on phytoplankton spring blooms (PSB) in the Yellow Sea, based on 25 years (1998–2022) of daily-scale high-resolution chlorophyll-a (Chl-a) data from satellites. The annual patterns of PSB indices (start, peak, and duration) clearly exhibited years which were weak (low peak: Chl-a &lt;0.80 mg/m³; short duration: &lt;15 days) and strong (high peak: Chl-a &gt;1.0 mg/m³; long duration: &gt;60 days). The EAR model detected the significant effects of SST and SSTV on PSB indices, with SSTV being the more important determinant. SST is highly related to the timing of PSB start and end, with the average SST of 9.5 ± 0.7 °C at the start and 13.2 ± 1.95 °C at the end. The amplitude of SSTV was negatively correlated with the daily increase in Chl-a, highlighting the role of SSTV in modulating the magnitude of PSB. At low SST, the deepening of the mixed layer prolonged the time for phytoplankton to equilibrate nutrient and light requirements, whereas at low SSTV, the rate of environmental change within the mixed layer was reduced, allowing phytoplankton to adapt to the environment more quickly. Since the accumulation of phytoplankton biomass depends largely on daily acclimated growth, our results suggest that increasing daily temperature anomalies and warming in future are detrimental to phytoplankton biomass accumulation, and may reduce the magnitude of PSB in mid-to high-latitude seas.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"290 ","pages":"Article 105479"},"PeriodicalIF":2.1,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143890790","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":"Vertical circulation and heat flux of coastal ocean fronts in the northwestern South China Sea","authors":"Keyi Tan ,&nbsp;Lingling Xie ,&nbsp;Junyi Li ,&nbsp;Mingming Li ,&nbsp;Qiang Li ,&nbsp;Quanan Zheng","doi":"10.1016/j.csr.2025.105478","DOIUrl":"10.1016/j.csr.2025.105478","url":null,"abstract":"<div><div>This study investigates the 3D structure and vertical circulation of the coastal ocean fronts in the northwestern South China Sea (NWSCS) by applying the generalized Omega equation to cruise observations in late August and early September 2018. The results reveal three summer density front zones (SUF1∼3) in the surface and subsurface layers. SUF1 is distributed along the coast with water depths shallower than 20 m and a density gradient larger than 0.2 × 10⁻³ kg m⁻⁴. It extends vertically from surface to bottom and is dominated by salinity gradient. In contrast, SUF2 and SUF3 are temperature-dominated frontal zones appearing in the offshore subsurface layer. SUF2 is in the cross-shelf direction between the 20-m and 40-m isobaths associated with upwelling waters originating from the south. The observed submesoscale fronts have a Rossby number of <em>O</em>(1). The diagnosed vertical velocities indicate that an upwelling peak of 4.2 × 10⁻⁵ m s⁻¹ is located near the coast in SUF1, while, in contrast, a maximum vertical velocity of −5.1 × 10⁻⁵ m s⁻¹ in the cross-shelf SUF2. Dynamic analysis results indicate that ageostrophic advection is the dominant term. The vertical heat fluxes derived from the vertical velocity and temperature anomaly are mainly positive both in SUF1 and SUF2, with a maximum value of 279.5 W m⁻² and 418.8 W m⁻², respectively, which are one order larger than the sea surface heat flux during the observation.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"290 ","pages":"Article 105478"},"PeriodicalIF":2.1,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143870034","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":"On the wind-driven European shelf sea-level variability and the associated oceanic circulation","authors":"Sam T. Diabaté ,&nbsp;Neil J. Fraser ,&nbsp;Martin White ,&nbsp;Barbara Berx ,&nbsp;Louis Marié ,&nbsp;Gerard D. McCarthy","doi":"10.1016/j.csr.2025.105466","DOIUrl":"10.1016/j.csr.2025.105466","url":null,"abstract":"<div><div>The shelf to the west of Ireland, France and the United Kingdom is a region where currents and sea level respond to the wind activity in a remarkable manner throughout a range of timescales. Using altimetry-obtained measurements and a wind reanalysis, we demonstrate in the present contribution how the sub-annual sea-level variability can be understood as a response to the wind action. The winds drive water towards (away from) the coastline through Ekman transport, yielding sea-level changes coherent along and across the shelf and with maximum amplitude at the coast. The alignment of the winds with the isobaths determines the magnitude of sea-level changes. To investigate the impacts of these changes on the circulation variability, we bring together a comprehensive dataset of 30+ in-situ observations of recent current changes. Using these measurements, we show that sub-annual changes in the shelf-edge circulation from the Goban Spur to the Faroe-Shetland Channel arise from the geostrophic adjustment to shelf sea-level variations induced by the Ekman-driven accumulation of water towards the coastline. Our analysis suggests that the along-isobath current generated through this mechanism are primarily found over the shelf, only <em>impinge</em> on the upper slope, and do not affect the circulation above greater depth (<span><math><mo>&gt;</mo></math></span>500 m). Nonetheless, important slope circulations such as the Rockall Slope Current are substantially influenced on their shoreward side by this simple geostrophic adjustment process. Because sea-level changes co-vary over large distances on the shelf, there also is remarkable along-isobath coherence in the associated current changes but we warn against concluding this is evidence for the continuity of an ‘European Slope Current’ circumnavigating the European slope from Portugal to Norway.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"291 ","pages":"Article 105466"},"PeriodicalIF":2.1,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143895008","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":"Reproduction features of ocean quahog, Arctica islandica (Linnaeus, 1767), in the White Sea","authors":"Alexandra Vladimirovna Gerasimova ,&nbsp;Lyudmila Pavlovna Flyachinskaya ,&nbsp;Lezin Petr Andreevich ,&nbsp;Nadezhda Andreevna Filippova ,&nbsp;Alexandra Sergeevna Kudryashova ,&nbsp;Alexey Ivanovich Starkov ,&nbsp;Nikolai Vladimirovich Maximovich","doi":"10.1016/j.csr.2025.105469","DOIUrl":"10.1016/j.csr.2025.105469","url":null,"abstract":"<div><div>The gametogenic cycle of ocean quahog, <em>Arctica islandica</em>, was investigated using specimens collected from a near-shore bed (10–15 m deep) in the Kandalaksha Bay of the White Sea during five summer seasons (1983, 1984, 2011, 2015, 2017). At present, the White Sea is the eastern distribution boundary of this mollusk. Local environmental conditions there differ considerably from those in other parts of its range, and many characteristics of the quahog populations in the White Sea are still poorly understood. In this study, we examined gonads from 384 ocean quahogs with shell length over 30 mm prepared with the use of standard histological techniques. The results showed that the reproductive cycle features <em>of A. islandica</em> in the White Sea were generally similar to those in other parts of its distribution. Clams in the spawning state were found mainly from the second half of July to October at a near-bottom water temperature of 9–15 °C. Both average (60–70 μm) and maximum (92–95 μm) size of mature oocytes of ocean quahogs from the White Sea were similar to those in North Atlantic populations. At the same time, we noted substantial interannual shifts in the spawning activity of <em>A. islandica</em> and showed that they reflected interannual changes in hydrological characteristics. However, it is unlikely that these shifts may affect the overall recruitment success of the population of this species.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"290 ","pages":"Article 105469"},"PeriodicalIF":2.1,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143821569","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":"Specific oceanographic conditions reflect meiofaunal communities: the case of a semi-enclosed gulf (Pagasitikos Gulf, Eastern Mediterranean)","authors":"K. Voulgaris,&nbsp;D. Vafidis","doi":"10.1016/j.csr.2025.105470","DOIUrl":"10.1016/j.csr.2025.105470","url":null,"abstract":"<div><div>Semi-enclosed gulfs exhibit distinct oceanographic conditions, influencing the inhabiting organisms and communities. Analyzing samples from 55 stations taken at 10 cm sediment depth in spring 2023 and belonging to three zones with different nutrient profiles, the meiofaunal communities in Pagasitikos gulf were examined, while their relationship with sediment properties, water chemistry and oceanographic conditions were investigated. Highest meiofaunal densities were observed in the internal gulf (458–1538 ind/10 cm²) near the main urban area, with lowest reported for the upper external gulf (36–594 ind/10 cm²). Two stations showed unusually high ciliate densities (454 and 598 ind/10 cm²) that could not be explained by any of the examined parameters. Highest richness but lowest evenness, Shannon and Simpson indices were reported for the internal gulf, followed by the lower external gulf, while the upper external zone showed lowest values. Multivariate analyses showed that all three nutrient zones are associated with distinct meiofaunal communities, with depth and sand content being the most important factors influencing the meiofaunal communities, while also discussing the potential effect of anthropogenic activities. Total organic carbon did not explain differences in meiofaunal composition, stressing the need for more precise measurements. This study showcases that gulf-specific oceanographic conditions such as water and nutrient stratification and hydrodynamics can play a key role in shaping meiofaunal communities.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"289 ","pages":"Article 105470"},"PeriodicalIF":2.1,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143808248","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 amplification and shallow water tides in a mixed semidiurnal coastal lagoon","authors":"Braulio Juarez ,&nbsp;Amaia Ruiz de Alegría-Arzaburu ,&nbsp;Julian Garcia Walther","doi":"10.1016/j.csr.2025.105468","DOIUrl":"10.1016/j.csr.2025.105468","url":null,"abstract":"<div><div>Tidal amplification of the semidiurnal M₂ component and the generation of shallow water tides were studied along a mixed semidiurnal system. Month-long water level and current velocity data were collected using three acoustic Doppler current profilers. These profilers were moored at depths of around 15 m in three locations: 10 km inland from the mouth of the lagoon, within the central region, and near the head of the lagoon. Harmonic and spectral analysis applied to observations showed landward amplification of a semidiurnal tidal wave and the generation of high frequency tides. A wavelet analysis also depicted the temporal variability of each frequency band showing the generation of shallow water tides that coincided with the spring tidal cycle. The observed tidal amplification and generation of shallow water tides were reproduced using a numerical model to explore the mechanisms involved in the generation of high frequency harmonics and to determine their spatial distribution. An analytical model replicated the amplification of M₂ in an idealized elongated channel under high frictional forces. The four nonlinear mechanisms that led to shallow water tides generation were computed and a relationship with velocities was established using wavelet coherence. The even quadratic frictional term showed the highest coherence with the third diurnal (i.e. MK3), and seventh diurnal (i.e. 4MO₇) frequency band. The fourth diurnal (i.e. M₄) band was consistently related with advection and the odd frictional term. The contribution of this research is twofold: firstly, it provides new observational evidence on tidal amplification due to friction and channel geometry; and it explores the mechanisms that can generate shallow water tides. These results enhance our understanding of tidal dynamics in coastal semi-enclosed bodies, such as coastal lagoons or estuaries.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"289 ","pages":"Article 105468"},"PeriodicalIF":2.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143769338","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 dynamics of the inner-shelf suspended sediments based on ADCP records and Rouse theory","authors":"Guilherme O. Cruz,&nbsp;Carlos A.F. Schettini","doi":"10.1016/j.csr.2025.105467","DOIUrl":"10.1016/j.csr.2025.105467","url":null,"abstract":"<div><div>The present study investigates the suspended sediment dynamics on the southern Brazilian continental shelf in the fluvial influence region of the Rio de la Plata and Patos Lagoon. Estimates of suspended sediment concentration (SSC) in the water column were obtained using data from a Doppler-effect acoustic Doppler current profiler (ADCP) and were compared with theoretical profiles obtained using Rouse's theory. To construct the theoretical profile, sediment settling velocity and shear velocity are necessary. The former was iteratively estimated to minimize the error between observed and modeled profiles. The latter was obtained from ADCP measurements. The comparison between observed and modeled profiles underwent a validation process considering the shape of the observed profile and environmental energy conditions. For the period of analyzed data, there was agreement between observed and modeled profiles 56 % of the time. When energy conditions were low (39 % of the time), and the gradient profile of SSC had higher concentrations near the surface than bottom (5 %), Rouse's theory did not apply. These results indicate that the main source of sediment in the water column is due to exchanges with the bottom. Although the study area is near the mouth of Patos Lagoon, the role of horizontal advection was negligible. By indirect inference, it was obtained that the median sediment size was 25 μm, with maximum values around 60 μm, which coincides with values suggested in the literature for coastal waters, with a median settling velocity of 0.14 cm/s. During periods of more energetic hydrodynamic conditions, downwelling events were associated with northward longitudinal currents, while upwelling occurred with southward currents. When the flow was directed northward, more material was transported near the bottom compared to southward flow.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"289 ","pages":"Article 105467"},"PeriodicalIF":2.1,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143759451","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":"Water masses distribution over the continental shelf off the Doce River (19.65°S), Southeastern Brazil: A fuzzy cluster analysis","authors":"Tayná Rosa Martins Paiva,&nbsp;Gabriela Corrêa Brasileiro,&nbsp;Guilherme Nogueira Mill,&nbsp;Eduarda Sousa Rangel,&nbsp;Renato David Ghisolfi","doi":"10.1016/j.csr.2025.105462","DOIUrl":"10.1016/j.csr.2025.105462","url":null,"abstract":"<div><div>This study investigates the seasonal variability of water masses across three sectors of the Espírito Santo Continental Shelf (ESCS): the North Sector, River Sector, and Environmental Protected Area (EPA) Sector. Utilizing a comprehensive dataset collected between November 2018 and July 2023, we applied fuzzy clustering methods to outline three water masses — Coastal Water (CW), Tropical Water (TW), and South Atlantic Central Water (SACW) — and analyze their distribution across the sectors. Our findings reveal distinct seasonal patterns in these water masses’ distribution and properties, influenced by factors like river discharge, coastal upwelling, and net heat flux. Absolute salinity distribution showed less saline river runoff water constrained to the coastal region around the Doce River mouth and eventually in the coastal North Sector due to increased continental discharge associated with reversal southerly winds. Winter is an exception to the conservative temperature and absolute salinity distribution due to the homogeneity of cold column water and the lower input of freshwater. Particularly noteworthy is the seasonal variability observed in the River Sector, where the influence of freshwater discharge from the Doce River significantly impacts water masses distribution. CW occurrence follows the distribution of absolute salinity and the area affected by the river plume, TW is associated with the Brazil Current, and SACW occurs over the continental shelf throughout the year (despite the weak thermal gradient during the winter). At the surface, TW prevails at all sectors beyond the river influence during the autumn and past the 30 m-isobath in the remaining seasons due to upwelled waters. This study provides valuable insights into the complex interactions shaping the oceanographic characteristics of the ESCS, highlighting the importance of considering seasonal variability in understanding coastal marine ecosystems.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"289 ","pages":"Article 105462"},"PeriodicalIF":2.1,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143714592","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}