Continental Shelf Research最新文献

{"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}

{"title":"Wave influence on water circulation and self-purification ability in a semi-enclosed sea","authors":"Fengze Zhao ,&nbsp;Yuanyi Li ,&nbsp;Dekui Yuan ,&nbsp;Kok Weng Tan ,&nbsp;Jian Sun","doi":"10.1016/j.csr.2025.105461","DOIUrl":"10.1016/j.csr.2025.105461","url":null,"abstract":"<div><div>Owing to significant variation in waves, studying the effects of waves on water exchange in semi-enclosed seas is challenging, and current knowledge on this subject is insufficient, which hinders effective management of coastal seas. In this study, wave-current coupled and water age models were established to investigate the influence of waves on water exchange in the Bohai Sea, China. The results show that waves do not affect basin-scale circulation in the Bohai Sea, and their effects on water exchange are restricted to nearshore regions, especially in estuaries with subaqueous deltas. Wave-induced age variation is around 5 %, peaking at 16 % nearshore. The wave effects on basin-scale water exchange are an order of magnitude smaller than those induced by winds, yet they govern the exchange process near the Yellow River Estuary. Analysis of age distributions with and without waves indicates that wind fetch and topographic conditions are important factors in determining the wave influence on currents. Wind and storm statistics suggest that north and northeast winds are dominant. Under these conditions, the nearshore regions in the south of the Bohai Sea and downwind areas experience strong wave forces. Due to drastic depth variations at the edges of subaqueous deltas, waves induce a strong longshore current flowing westward into Laizhou Bay, with the wave influence extending nearly 100 km.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"289 ","pages":"Article 105461"},"PeriodicalIF":2.1,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143705407","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":"Assessment of eutrophication in a Ramsar site (Akyatan Lagoon) in the Northeastern Mediterranean Sea","authors":"Nahit Soner Börekçi,&nbsp;İsmail Akçay,&nbsp;Özgür Özbay,&nbsp;Mehmet Tahir Alp","doi":"10.1016/j.csr.2025.105465","DOIUrl":"10.1016/j.csr.2025.105465","url":null,"abstract":"<div><div>Coastal lagoons are transitional zones between riverine and marine systems where nutrients and contaminants often accumulate in these aquatic environments. In the present study, physical and biochemical data were obtained from the five stations between January and December 2022 for the determination of trophic status in the Akyatan Lagoon. The study results indicated the values of physical and eutrophication-related parameters displayed spatial and temporal variability. The trophic status of Akyatan Lagoon was determined by using two multi-metric classification tools as Trophic index (TRIX) and the Trophic status index (TSI). The calculated TRIX values ranged from 4.88 to 7.90 whilst the TSI values varied between 50.0 and 77.4. The strong and positive correlations between the TRIX and TSI values with their high values strongly suggested hypereutrophic conditions in the ecologically and economically important Akyatan Lagoon caused by contaminated Seyhan River inflows due to terrestrial nutrients and organic matter inputs.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"289 ","pages":"Article 105465"},"PeriodicalIF":2.1,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685262","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":"Distribution of rare earth elements and their signatures from the Mackenzie River delta to the abyssal Arctic Ocean","authors":"Thomas Bossé-Demers ,&nbsp;Charles Gobeil ,&nbsp;Bennet Juhls ,&nbsp;Martine Lizotte ,&nbsp;Michael Fritz ,&nbsp;Lisa Bröder ,&nbsp;Atsushi Matsuoka ,&nbsp;Santiago Mareque ,&nbsp;Raoul-Marie Couture","doi":"10.1016/j.csr.2025.105464","DOIUrl":"10.1016/j.csr.2025.105464","url":null,"abstract":"<div><div>The Mackenzie River is North America's largest contributor of freshwater and sediment to the Arctic Ocean. Here, we evaluate the potential of rare earth elements (REE) as tracers of its sediment sources and fate, from the river mouth to the deep Arctic Ocean. We collected sediment cores from 21 sites, from the delta to the marine shelves, slopes and basins and measured the spatial and down-core distribution of total, leached and residual REE concentrations. Our results show that the proportion of leached REE is highest in the delta. This proportion decreases with distance from the river, suggesting mixing with other sediment sources, REE loss to the residual phase, or REE scavenging via adsorption and complexation in coastal waters. Normalized REE concentrations plotted against their atomic number provide regional signatures. The leached REE signatures indicate medium REE enrichment in the Mackenzie Delta, an enrichment that diminishes with distance from the delta. We then used a similarity index (SI) to investigate the divergence amongst REE signatures, with riverine and deep marine basin values as endmembers for the calculation. Our results highlight the influence of the Mackenzie Region sediments on the Beaufort Sea margin. Overall, our findings demonstrate that REE are relevant tracers for identifying sediment sources and that tracking REE distribution from the delta to the deep Arctic Ocean offers additional insights into sediment transport mechanisms.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"289 ","pages":"Article 105464"},"PeriodicalIF":2.1,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatial variation of marine primary productivity over ridge and trough: A case study in the East China Sea","authors":"Lu Zhang ,&nbsp;Lulu Qiao ,&nbsp;Ze Wang ,&nbsp;Guangxue Li ,&nbsp;Nan Wang ,&nbsp;Yi Zhong ,&nbsp;Yang Zhang","doi":"10.1016/j.csr.2025.105463","DOIUrl":"10.1016/j.csr.2025.105463","url":null,"abstract":"<div><div>Tidal sand ridges are widespread in continental shelves and have attracted much attention due to their effects on ecology, geochemistry, and hydrodynamics. Typical tidal sand ridges are widely distributed throughout the East China Sea (ECS). Previous studies proposed that marine primary productivity (MPP) displays different spatial variations in ridges and troughs. Chlorophyll-a (Chl-a) and total organic carbon (TOC) are effective proxies for MPP. This study examined the influence of topography on MPP. The data analyzed included the Chl-a product from Himawari-9 and TOC and stable organic carbon isotopic compositions from surface samples in the ECS. Our results demonstrate that Chl-a displays an alternating pattern of significant fluctuations in the ECS. Chl-a concentrations in the ridge were higher than those in the trough and exhibited different characteristics at the surface and bottom of the water column. Biogeochemical parameters showed significant differences between ridges and troughs. Suspended particulate matter (SPM) and median particle size (D₅₀) in the ridges were finer than those in the troughs, indicating that fine particulates are beneficial for the enrichment and adsorption of organic carbon, which is consistent with TOC data. The C/N and δ¹³C data indicate that the organic matter in our study area originates from terrestrial and marine sources. According to the N/C calculation results, the proportion of marine organic carbon is higher on the ridge. Moreover, the temperature and nutrients, as the dominant factors affecting MPP, appear to vary in ridges and troughs. Understanding the effects of topography is important for clarifying the distribution of phytoplankton and predicting marine biological disasters.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"289 ","pages":"Article 105463"},"PeriodicalIF":2.1,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685204","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":"Long-term variations in sea ice extent can influence trends in maximum sea level in the northeastern Baltic Sea","authors":"Ülo Suursaar ,&nbsp;Katre Luik ,&nbsp;Martin Mäll ,&nbsp;Jaak Jaagus ,&nbsp;Hannes Tõnisson","doi":"10.1016/j.csr.2025.105451","DOIUrl":"10.1016/j.csr.2025.105451","url":null,"abstract":"<div><div>Compared to the relative mean sea level changes at Estonian tide gauges, the maximum sea levels have increased faster, by 10–40 cm over the past hundred years. It has been argued that the west-facing coast is sensitive to long-term changes in the westerly wind component and storminess. In addition to those, we test the hypothesis that the decrease in Baltic Sea ice cover can also be a reason for higher surges. To study trends, we use long-term sea level and meteorological data from Estonian coastal stations and ice records in the Gulf of Riga. The ERA5 forced WRF-FVCOM modelling suite is used to quantify the effect of the lack of ice cover on sea level patterns in the Gulf of Riga and on the maxima at Pärnu during three storms. According to the linear trend, air temperatures on the Estonian coast have increased by about 2.5 °C between 1950 and 2023, and the number of ice days has decreased by 62 % at Kihnu and by 42 % at Pärnu. The sea level trend-changing mechanism can apply in two ways. Firstly, some mid-winter extremely high storm surges have occurred in ice free conditions, especially in more recent decades. And secondly, when some strong winter storms did not cause remarkably high sea level events in the ice-covered Gulf of Riga, but the FVCOM indicated the potential for storm surges of at least 60 cm higher than took place. Such events could have had a notable impact in the first half of the 20th century, when seasonal ice cover on the Baltic Sea was more extensive than it is nowadays. The combination of a decreasing ice trend and an increasing probability of undamped storm surges can contribute to a steepening of sea level maxima and higher quantile trends in centennial time series.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"289 ","pages":"Article 105451"},"PeriodicalIF":2.1,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685261","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring concentration of chlorophyll-a, SST and salinity variability over the Bay of Bengal: Integrating ROMS model and in-Situ observations","authors":"Yaduvendra Singh,&nbsp;Vivek Kumar Pandey,&nbsp;Prabha Kushwaha","doi":"10.1016/j.csr.2025.105452","DOIUrl":"10.1016/j.csr.2025.105452","url":null,"abstract":"<div><div>This study is to replicate the oceanic circulation pattern in the Bay of Bengal (BoB) spanning from 1998 to 2014 using Regional Ocean Modelling Systems (ROMS). The model's performance in seizing the ocean's most vital features, such as sea-surface temperature (SST), salinity, chlorophyll-a (Chl-a) concentration, and surface currents, has been analyzed. The model represents spatial dynamics, with seasonal change progressing from the northeast to the southwest within the Bay of Bengal. From MAM, the southern BoB and central region of BoB areas demonstrate warming trends, whereas the SST increase in the northern BoB is a result of JJAS. These shifts are a result of changes in sun irradiation, mixed layer depth variations, and freshwater influx. The model shows relative alignment with the observed data, except during JJAS, where higher SSTs were observed. These higher SSTs are likely due to the intricate interactions involving monsoon-driven atmospheric variability, which impacts surface heating and freshwater influx, as well as unresolved model parameters related to vertical mixing and heat flux processes. The research work to be done requires quantification of the model's performance, and the statistical methods yield a moderate correlation for both SST and concentration of Chl-a. A variety of factors, including upwelling, coastal dynamics, and atmospheric processes, can explain these patterns. The paper emphasises the idea of the complex character of coastal processes, and it emphasises the importance of adequate representation of these phenomena in the models. The modelling of concentrations of Chl-a also exhibits a distinct seasonal trend, and the model duplicates essential features but shows biases near the coastal areas, likely due to limitations in the model's horizontal resolution, the treatment of freshwater input, and the representation of coastal upwelling processes. Positive and negative anomalies of the SST and the concentration of Chl-a are connected with the complex interaction of ocean-atmosphere systems, thereby demonstrating the interplay of different factors. Fundamentally, the research points to the significance of faithful simulation of ocean circulation and coupled elements for the proper assessment of the highly complicated BoB dynamics.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"289 ","pages":"Article 105452"},"PeriodicalIF":2.1,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143644304","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":"Impact of anthropogenic activities on bacterial community diversity in a coastal city: A case study from Shantou","authors":"Jiayu Li ,&nbsp;Yue Zheng ,&nbsp;Varenyam Achal","doi":"10.1016/j.csr.2025.105450","DOIUrl":"10.1016/j.csr.2025.105450","url":null,"abstract":"<div><div>Bacterial communities in coastal environments are significantly influenced by human activities, serving as key indicators of ecological health and water quality. This study examines the impacts of anthropogenic activities on the diversity of bacterial communities within the coastal sands of Shantou, China, a rapidly developing tourist destination. We collected sand samples from four beaches with varying levels of human activity and analyzed their physicochemical properties, including pH, salinity, nitrate concentration, and available phosphorus. Bacterial community compositions were assessed using cluster heat maps to identify species distributions across multiple taxonomic levels. The results showed consistent pH levels but varied salinity and nutrient concentrations corresponding to the intensity of human activity. Notably, elevated nitrate levels at tourist-heavy sites suggested a direct link between tourism and coastal nitrogen dynamics. Five bacterial taxa were identified as potential pollution indicators, <em>Woeseia</em> and <em>Pseudomonas</em> were consistently abundant across all studied sites. Comparative analysis revealed distinct contamination patterns, with some sites showing significant microbial community shifts. These findings highlight the need for effective management strategies to mitigate the adverse effects of human activities on coastal bacterial biodiversity and ecosystem health.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"289 ","pages":"Article 105450"},"PeriodicalIF":2.1,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143636603","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":"Mediterranean Sea: An overview of the spatial distribution of surficial sediment in relation to their origin, seabed relief and water circulation patterns","authors":"Serafeim E. Poulos","doi":"10.1016/j.csr.2025.105449","DOIUrl":"10.1016/j.csr.2025.105449","url":null,"abstract":"<div><div>The present paper provides a conclusive picture of the origin and spatial distribution of terrigenous versus biogenic carbonate material in the surficial unconsolidated seafloor sediments of the Mediterranean Sea, considering the different sources of inorganic and organic material, the seafloor relief and water circulation patterns. Terrigenous material dominates about three quarters of the Mediterranean seafloor, mainly in the central Mediterranean and the northern parts of the western and eastern Mediterranean. This dominance is attributed to significant riverine inputs and the generally oligotrophic nature of Mediterranean waters. Conversely, biogenic carbonate-rich sediments are more prevalent in the southern parts of the central and eastern Mediterranean where, despite the oligotrophic conditions, the presence of biogenic carbonate is maintained by minimal terrestrial contributions, mainly from Saharan dust deposition. Surface water circulation, although less important than riverine fluxes and primary production in shelf waters, plays an important role in sedimentation processes beyond the shelf break and is responsible for localized open sea sediment distribution patterns. Finally, anthropogenic interventions and expressions of ongoing climate change are discussed in relation to the production, transfer and deposition of both terrigenous and biogenic sediments.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"290 ","pages":"Article 105449"},"PeriodicalIF":2.1,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143842621","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 subtidal transport through the Guafo Mouth connecting the open ocean and the Chilean Inland Sea in southern Chile","authors":"Valentina Mundaca ,&nbsp;Vincent Echevin ,&nbsp;Odette A. Vergara ,&nbsp;Osvaldo Artal ,&nbsp;Héctor H. Sepúlveda","doi":"10.1016/j.csr.2025.105428","DOIUrl":"10.1016/j.csr.2025.105428","url":null,"abstract":"<div><div>The Chilean Inland Sea (CIS) and the fjords region in Southern Chile host human activities such as salmon aquaculture. During the productive austral summer, the CIS exchanges heat, salt, dissolved oxygen, and nutrients with the Southern Pacific Ocean via the Guafo Mouth, a very shallow strait. Tides influence the productivity of the CIS, a high-frequency forcing typically not considered in circulation models when estimating exchange fluxes. In this work, the inflow, outflow, net, mass, and nutrient fluxes through the Guafo Mouth are evaluated using a high-resolution regional model forced by tides. Model output (temperature, salinity, and currents) is compared to hydrodynamic data. The impact of tidal forcing on summer-mean currents and transports is quantified. These findings are compared with results from a lower-resolution, commonly used, general circulation model. A Lagrangian modeling approach highlights that the water masses transiting from the open ocean through the Guafo Mouth mainly originate from the region south of the mouth.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"288 ","pages":"Article 105428"},"PeriodicalIF":2.1,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143610698","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}