{"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}
Valentina Mundaca , Vincent Echevin , Odette A. Vergara , Osvaldo Artal , Héctor H. Sepúlveda
{"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 , Vincent Echevin , Odette A. Vergara , Osvaldo Artal , 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}
Ailin Yao , Yue Ming , Mengyu Wang , Xintong Jiang , Lixin Zhu , Xianye Wang , Lei Gao
{"title":"Stepwise variations of nutrients and organic matter in the fragmented Changjiang River by two big “dams”: One visible and one invisible","authors":"Ailin Yao , Yue Ming , Mengyu Wang , Xintong Jiang , Lixin Zhu , Xianye Wang , Lei Gao","doi":"10.1016/j.csr.2025.105438","DOIUrl":"10.1016/j.csr.2025.105438","url":null,"abstract":"<div><div>The transport flux of biogenic elements from large rivers such as the Changjiang (Yangtze) River, played a critical role in determining the estuarine and coastal environments. However, the combined effects of human activities and natural factors had resulted in complex spatiotemporal variations of biogenic elements along the river. In this study, sampling was conducted on four campaigns through the Changjiang River in different seasons during 2021 and 2022. The results showed that two suspended particulate matter (SPM) Surge Zones with rapidly increased SPM concentrations emerged, one between Yichang and Yueyang, downstream of the Three Gorges Dam (TGD), and the other between Wuhu and Xuliujing, upstream of the estuarine area. The two SPM Surge Zones had acted as the two “dams” or “walls” that separated the Changjiang River mainstream and led to the formation of two SPM Deposition Zones, one in the Three Gorges Reservoir (between Chongqing and Yichang), and the other in the middle and lower reaches (between Wuhan and Wuhu). Within these SPM Deposition Zones, SPM concentrations slowly decreased, and the proportion of particulate organic carbon in SPM increased. This reservoirization of the river water hindered the concentration increase of nutrients with the river flow, despite their continuous supplies from river banks by anthropogenic activities. The different patterns of nutrients and organic matter variations in the SPM Surge Zones and in the SPM Deposition Zones highlighted a “stepwise” characteristic in their distribution. The Changjiang River showed a deeply reservoir-like characteristic at present, which, along with other anthropogenic activities, had also driven significant decadal trends of nutrients and organic matter in the river waters.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"287 ","pages":"Article 105438"},"PeriodicalIF":2.1,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143453694","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":"Why does surface chlorophyll-a bloom in Taiwan Shoal all year round?","authors":"Qi Feng , Rufa’i Isyaku , Yulin Zhu , Ling Hao , An Zhang , Xin Zhou , Haibin Lü","doi":"10.1016/j.csr.2025.105437","DOIUrl":"10.1016/j.csr.2025.105437","url":null,"abstract":"<div><div>Based on 10 years (January 2012–December 2021) of satellite observations, sea surface chlorophyll-a (Chl-a) was found to be present in the Taiwan Shoal throughout the year. The underlying mechanisms were investigated. The seasonal mechanism was investigated based on satellite remote sensing data, reanalysis data, and Argo buoy data. The relationship between the seasonal variation of Chl-a and sea surface temperature (SST), wind speed, photosynthetically active radiation (PAR) and salinity in Taiwan shoals was calculated. The results revealed that a large amount of Chl-a was present in the study area throughout the year, where the Chl-a concentration reached a maximum of 0.88 mg m<sup>−3</sup> in July, which was 1.76 times greater than that (0.50 mg m<sup>−3</sup>) in April. In summer, there was increased upwelling and a thinner mixed layer, which pulled the bottom nutrients to the surface and led to the inflow of South China Sea water (SCSW) with Chl-a in the horizontal direction. In winter, the Kuroshio Branch Water (KBW) intrusion and the inflow of Chinese coastal water into the northern part of the Taiwan Strait (TWS) resulted in a zone of high temperature gradient, whereas the strong northeasterly monsoon strengthened the vertical mixing of the study area, which coincided with the zone of high Chl-a values. The combination of nutrient-rich waters, suitable temperatures in spring, and sufficient photosynthetically active radiation (PAR) in autumn provides favorable conditions for the accumulation of surface Chl-a. This study provides valuable insights into the ecological impacts of seasonal variations in Chl-a blooms in the TWS.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"287 ","pages":"Article 105437"},"PeriodicalIF":2.1,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143436757","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":"Bibliometric analysis of microplastics research: Advances and future directions (2020–2024)","authors":"Zhilin Xing , Wenting Fu , Liangjie Li , Shan Wu","doi":"10.1016/j.csr.2024.105371","DOIUrl":"10.1016/j.csr.2024.105371","url":null,"abstract":"<div><div>Microplastics are a critical environmental concern due to their pervasive distribution and hazards. This study used Citespace software for a bibliometric analysis of microplastics research from 2020 to 2024, based on Web of Science papers. It covered sources, distribution, ecotoxicity, human health impacts, and mitigation measures. Findings showed a rapid increase in the number of related publications, with research focus gradually becoming more specialized, including advances in specific areas such as pollution status, ecotoxicology, detection technologies, and pollution control methods. Research focused on high plastic consumption regions like Europe, North America, and Asia, using innovative methods like high-throughput sequencing and nanotechnology. Keywords clustering identified primary research hotspots: microplastic pollution, ecotoxicity, pollution control, and human health impacts. Despite progress, challenges such as incomplete detection methods, the need for better risk assessment models, and improved pollution control technologies remain. This study offers insights and future research directions for microplastics pollution prevention and environmental protection.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"285 ","pages":"Article 105371"},"PeriodicalIF":2.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145103","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}
Eleonora Carol , Rosario Acosta , Guido Borzi , María Paula Leal , Mattia Gaiolini
{"title":"Hydrogeochemical evaluation of Caleta de Los Loros Patagonian salt marsh in response to the geomorphological evolution of the coast during the Holocene","authors":"Eleonora Carol , Rosario Acosta , Guido Borzi , María Paula Leal , Mattia Gaiolini","doi":"10.1016/j.csr.2025.105403","DOIUrl":"10.1016/j.csr.2025.105403","url":null,"abstract":"<div><div>Sea level oscillations occurred during the Quaternary conditioned the marsh landscape by limiting the factors that regulate water salinity in this environment. The aim of this work was to evaluate geochemical processes that condition groundwater salinity in Caleta de Los Loros marsh considering geomorphological – climatic factors associated with the Holocene evolution of this Argentinean Patagonia coastal area. In this sense, a mapping and a geomorphological characterization was performed based on satellite images, digital elevation models and field surveys. A monitoring network including both surface and groundwater was made in order to measure <em>in situ</em> pH and electrical conductivity and to take samples to determine major ions and stable isotopes in the laboratory. The set of results obtained highlights that variations in salinity, major ions composition and isotopic signal recorded in the groundwater of Caleta de Los Loros marsh vary in the different sectors of the intertidal plains resulting from geomorphological evolution from the middle Holocene to the present day. The older intertidal deposits (2100 years B.P.) currently located in the more continental sector host high salinity environments with high marshes vegetated with <em>Salicornia</em> sp. The hydrochemical and isotopic signal indicates that in them salinity responds primarily to evaporitic salt dissolution – precipitation cycles. Meanwhile, more coastal intertidal deposits have less than 500 years and they host low marsh environments vegetated with <em>Spartina</em> sp. Hydrochemistry and isotopic composition in them reflect that tidal water flooding is the main water contribution to the system, being marsh groundwater hydrogeochemichally similar to surface water. Locally, contributions from adjacent beach ridges and hydrochemical variations associated with CO<sub>2(g)</sub> dissolution were also recognized. Understanding environmental changes that occur in marshes as a product of their geomorphological quaternary evolution allows to understand the distribution of salinity patterns that develop in them and to give an idea of the time scale on which the salinization of these environments occurs.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"285 ","pages":"Article 105403"},"PeriodicalIF":2.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145282","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}
Jin-Yun Li , Ye-Yang Hou , Wan-Jun Liao , Ying Guo , Yong He , Liang-Ying Liu
{"title":"Polycyclic aromatic hydrocarbons and their derivatives in sediments from the Okinawa Trough and South China Sea: Occurrence, sources, profiles, and implications for anthropogenic activities","authors":"Jin-Yun Li , Ye-Yang Hou , Wan-Jun Liao , Ying Guo , Yong He , Liang-Ying Liu","doi":"10.1016/j.csr.2025.105406","DOIUrl":"10.1016/j.csr.2025.105406","url":null,"abstract":"<div><div>Sediments from the Middle Okinawa Trough (MOT) and Southwest Basin were analyzed for polycyclic aromatic hydrocarbons (PAHs) and their halogenated and nitrated derivatives. No halogenated PAHs were detected, whereas 6 nitrated PAHs were observed in three samples from the MOT (0.960−6.46 ng/g). The concentrations of Σ<sub>18</sub>PAH in the sediment of the MOT (average124 ng/g) were statistically higher than those of the Southwest Basin (39.7 ng/g). The MOT sediments were dominated by 4−5-ring PAHs, whereas the Southwest Basin sediments were dominated by 3-ring PAHs. The regional differences in concentrations and composition profiles were likely due to the different patterns of regional environmental and/or anthropogenic factors, e.g., climate and energy consumption. Sedimentary PAHs in the MOT were primarily derived from petroleum and/or petroleum combustion, while those in the Southwest Basin were mainly from petroleum. The findings suggest that environmental management and pollution control strategies should consider the specific pollution source in different regions.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"285 ","pages":"Article 105406"},"PeriodicalIF":2.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145288","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":"Macrofauna community structure and population dynamics in the Flemish bank region: Assessing long-term change in the Anthropocene","authors":"Sarah Broos , Gert Van Hoey , Carl Van Colen","doi":"10.1016/j.csr.2024.105387","DOIUrl":"10.1016/j.csr.2024.105387","url":null,"abstract":"<div><div>Benthic communities in continental shelf seas are influenced by human activities, yet assessing long-term change remains impeded by the scarcity of baseline data predating the proliferation of human activities. In this study, we considered the oldest macrofauna data from Van Veen samples collected in autumn 1970–1971 in a shallow soft-sediment seabed south of the Nieuwpoort Bank in the Belgian Part of the North Sea (BPNS). Both archived data in notebooks and hitherto unprocessed samples were considered. The community structure and biodiversity of these samples were compared with samples from autumn 2016. Furthermore, we compared (bi)monthly dynamics of indicator taxa for muddy sands (<em>Abra</em> spp.) and fine-medium sands (<em>Nephtys</em> spp.) present in the area with a time series collected in 2002–2003. Our findings reveal that both habitat types became richer in macrofauna species number and diversity. The invasive species that colonized the area between sampling periods explained <1 % of observed community structure changes. Overall, most taxa had higher population densities in 2016 compared to 1970–1971. Population densities varied seasonally, peaking in August 2016, and with less distinct recruitment dynamics in 1970–1971, confirming lower overall population densities in that period, especially for Abra. We discuss these results in relation to datasets discrepancies, climate variability, and sediment fining, acknowledging limitations in sampling design and processing methods. Nevertheless, this data rescue exercise proved valuable for understanding marine ecosystem changes, highlighting the potential of ‘old’ archived data and samples from the early Anthropocene.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"285 ","pages":"Article 105387"},"PeriodicalIF":2.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145143","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}
Ernesto Villarino , Anders Lanzén , Naiara Rodriguez-Ezpeleta , Iñaki Mendibil , Angel Borja , Iñigo Muxika , Xabier Irigoien , Joxe Mikel Garmendia , Guillem Chust
{"title":"Contrasting diversity patterns using Autonomous Reef Monitoring Structures deployed in pelagic vs. benthic environments","authors":"Ernesto Villarino , Anders Lanzén , Naiara Rodriguez-Ezpeleta , Iñaki Mendibil , Angel Borja , Iñigo Muxika , Xabier Irigoien , Joxe Mikel Garmendia , Guillem Chust","doi":"10.1016/j.csr.2024.105358","DOIUrl":"10.1016/j.csr.2024.105358","url":null,"abstract":"<div><div>Recent developments of data-driven standardized sampling tools have reduced knowledge gaps on benthic biodiversity and larval dispersal patterns. Here, we present a new application to estimate benthic spatial biodiversity patterns and evaluate potential larval dispersal from nearshore coast to the pelagic environment. To do so, we combined DNA metabarcoding and imagery on Autonomous Reef Monitoring Structures (ARMS) deployed in pelagic and nearshore benthic systems across the Bay of Biscay's Basque Coast. Results reveal a remarkably lower biodiversity in pelagic relative to benthic ARMS as well as strong spatial patterns in community composition with the pelagic ARMS greatly differing to the benthic ones according to both metabarcoding (ANOSIM R = 0.82; <em>p</em> = 0.002) and image analysis (ANOSIM R = 0.87; <em>p</em> = 0.001). We also show that a large portion of the larvae inhabiting the pelagic domain (83.5%) probably originates from benthic habitats, while the benthic community shared across pelagic and benthic habitats is considerably lower (24.9%). Further, we also analyzed which benthic species successfully use the pelagic environment to disperse across the ocean from nearshore coast, and found that the unique benthic taxa inhabiting the pelagic ARMS consist of organisms with typically larger dispersal distances relative to strictly sessile taxa with direct larvae development found only in rock-attached benthic ARMS. Overall, these findings suggest that the benthic system acts as population source delivering species towards a less diverse pelagic domain. Taken together, this novel application of ARMS deployed in pelagic systems has the potential to identify the often overlooked yet critically important benthic community structure, as well as to unveil how dispersal pathways across benthic and pelagic habitats can shape biodiversity patterns of coastal ecosystems.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"285 ","pages":"Article 105358"},"PeriodicalIF":2.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145144","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}