Continental Shelf Research最新文献

{"title":"Global marine plastic pollution: Sources, distribution, implications on human health and mitigation strategies","authors":"Abhay B. Fulke ,&nbsp;Shreya Bhanushali ,&nbsp;Harshal S. Jadhav","doi":"10.1016/j.csr.2025.105578","DOIUrl":"10.1016/j.csr.2025.105578","url":null,"abstract":"<div><div>Plastic pollution has emerged as a pressing environmental crisis, with global production surging from 2 million tonnes per year in the 1950s to a staggering 460 million tonnes in 2019. A substantial portion of this plastic waste, over 260,000 tonnes, finds its way into the world's oceans, profoundly impacting marine basins worldwide. Research indicates that an estimated 10 million metric tons of plastic are annually released into aquatic bodies. If current trends continue, an alarming 33 billion tonnes of plastic are projected to accumulate in marine ecosystems by 2050. The pervasive issue of marine litter is dominated by plastic debris, constituting approximately 80 % of all marine waste. Their widespread distribution has raised serious environmental and public health concerns. This comprehensive review identifies the diverse sources of marine plastic whose accumulation results in Global Marine Plastic Pollution (GMPP) and the global distribution of microplastics in the surface waters and sediments across continents and oceans. Moreover, this phenomenon leads to the ingestion of microplastics by various organisms within the marine ecosystem. The alarming nature of this situation calls for immediate action, which has been addressed through the implementation of international policy instruments at the global, regional, and national levels to combat marine plastic pollution. Furthermore, this review discusses the pivotal factors that promote the ingestion of microplastics and assesses their potential implications on marine organisms and human health.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"296 ","pages":"Article 105578"},"PeriodicalIF":2.2,"publicationDate":"2025-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145418560","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 water flow in presence of various obstructions: description and validation of a generic module for 2- and 3-dimensional simulations","authors":"Florian Ganthy ,&nbsp;Romaric Verney ,&nbsp;Arnaud Le Pevedic ,&nbsp;Franck Dumas","doi":"10.1016/j.csr.2025.105580","DOIUrl":"10.1016/j.csr.2025.105580","url":null,"abstract":"<div><div>In coastal areas, various types of biological and anthropogenic structures significantly influence the flow and related sediment dynamics. In this paper, we describe a new generic flow-obstruction module, designed to represent both upward or downward, rigid or flexible structures. This module provides a particularly accurate representation of flow velocities in the presence of flexible obstructions, due to a thorough description of their bending. The obstruction/flow interaction module can operate either in 3D or 2D mode. It also offers the possibility of incorporating multiple types of obstructions within a single mesh, which is invaluable when modeling realistic ecosystem dynamics. Module validation was carried out using flume experiments on seagrasses, as well as using numerical studies involving two anthropogenic structures: mussel long-lines and oyster tables. The coupled hydrodynamic/obstruction model yielded excellent results for 2D/3D velocity fields with minimal calibration efforts. This module can be integrated into any hydrodynamic coastal model and is aimed at being upscaled to a regional scale, offering the potential to explore future trajectories regarding the vulnerability of coastal systems in response to global change, or to identify restoration measures in engineered coastal systems.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"295 ","pages":"Article 105580"},"PeriodicalIF":2.2,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145266903","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":"Plutonium radioisotopes as radiotracers of sedimentation processes in the Black Sea coastal areas","authors":"A.A. Paraskiv,&nbsp;N.N. Tereshchenko,&nbsp;V. Yu Proskurnin","doi":"10.1016/j.csr.2025.105579","DOIUrl":"10.1016/j.csr.2025.105579","url":null,"abstract":"<div><div>The vertical distribution of plutonium radioisotopes (²³⁸Pu and ^239+240Pu) in five bottom sediment cores from the coastal marine area of Sevastopol Bay (the Black Sea) was studied. Based on the analysis of the ²³⁸Pu, ^239+240Pu activity and ²³⁸Pu/^239+240Pu activity ratio profiles, geochronological dating of bottom sediments was carried out and the main parameters of sedimentation processes (SR – sedimentation rate and MAR – mass accumulation rate) were calculated. It was found that each of the studied areas of the Sevastopol Bay has individual sedimentation features, which are reflected in SR and MAR values. SR values ranged from 2.5 to 7.5 mm year⁻¹ while MAR – from 1679 to 4833 g m⁻²·year⁻¹. The obtained results indicate that the intensity of water self-purification via plutonium removal into the sediments varies within the studied areas. It is shown that under the conditions of the spatiotemporal regime of plutonium input into the Black Sea it is possible to determine the SR and MAR for two time periods: 1962–1986 and 1986–2019. It has been established that on a half-century scale the SR and MAR have changed in the Sevastopol Bay. Thus, in the post-Chernobyl period, in the bay mouth, the SR and MAR increased by 2.1 and 1.8 times, respectively, while in the bay headwaters they decreased by 2.0 and 2.3 times, respectively. These changes are apparently a consequence of the construction of hydraulic structures both in the Sevastopol Bay and in its drainage basin.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"295 ","pages":"Article 105579"},"PeriodicalIF":2.2,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145266907","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":"Changes in free-living zooxanthellae abundance during summer in a temperate Japanese coastal sea (Takashima, Japan)","authors":"Hiroyuki Takasu ,&nbsp;Takanobu Yamaguchi ,&nbsp;Maiko Ito ,&nbsp;Kotaro Miyahara ,&nbsp;Rintaro Kiyama ,&nbsp;Manabu Fukumura ,&nbsp;Shuzo Komura","doi":"10.1016/j.csr.2025.105577","DOIUrl":"10.1016/j.csr.2025.105577","url":null,"abstract":"<div><div>Free-living or exogenous zooxanthellae play a crucial role in coral survival; however, their ecological dynamics remain largely unexplored. This study focused on tracking the abundance of free-living zooxanthellae (Clades A to F) in seawater around the temperate coastal sea (Takashima, Japan) from summer to early autumn using quantitative polymerase chain reaction (qPCR). In addition, we examined the influence of temperature, light conditions (photosynthetic photon flux density [PPFD]), dissolved inorganic nitrogen (DIN), and coral health on the abundance of zooxanthellae. Our findings revealed an increase in the abundance of free-living zooxanthellae from late summer to early autumn, irrespective of clade. A significant negative correlation was observed between the ribosomal RNA (rRNA) gene copy number, amplified using a universal primer, and coral health scores. Conversely, there was a positive correlation between the rRNA gene copy number and seawater temperature. The relationship between PPFD and DIN was not significantly correlated with rRNA gene copy number. Notably, the rRNA gene copy number, amplified using the Clade C primer, was the most abundant and exhibited a significant positive correlation with seawater temperature, whereas it was negatively correlated with coral health scores. The increase in the abundance of free-living zooxanthellae, particularly Clade C, in seawater was facilitated by rising seawater temperatures and the release of zooxanthellae cells from host corals, with the latter likely being the predominant factor. To our knowledge, this is the first study to monitor temporal changes in the abundance of free-living zooxanthellae in seawater.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"295 ","pages":"Article 105577"},"PeriodicalIF":2.2,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145220402","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":"Insights into effects of salinity stress on the body-size spectrum of periphytic protozoan fauna in marine ecosystems","authors":"Awais Ali ,&nbsp;Xiaoxiao Zhong ,&nbsp;Guangjian Xu ,&nbsp;Henglong Xu","doi":"10.1016/j.csr.2025.105575","DOIUrl":"10.1016/j.csr.2025.105575","url":null,"abstract":"<div><div>To evaluate the impacts of salinity stress on the community functioning of marine ecosystems, a 1-month bioassay was performed using periphytic protozoan fauna as the test organism community within a gradient of salinity 9, 19, 29 (control), 39, and 49 PSU. The samples of the test organism assemblage were collected from an intertidal zone of the Yellow Sea, northern China. In terms of both the frequency of occurrences and the probability density, the body-size spectrum of the test protozoan fauna was clearly shifted with the test scale of salinity variability. The significant changes occurred in the body-size distinctness measures, which followed a unique trend among salinity gradients. Furthermore, the body-size spectrum showed a significant departure from an expected pattern at 9 PSU. Therefore, it is suggested that the body-size spectrum of periphytic protozoan fauna may be used as a useful tool for evaluating the effects of salinity stress on community functioning in marine environments.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"295 ","pages":"Article 105575"},"PeriodicalIF":2.2,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145158152","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":"Interaction and variability of silicon and carbon associated with particulate matter in the Changjiang and Yellow Rivers","authors":"Xiangbin Ran ,&nbsp;Yingxiao Li ,&nbsp;Xiaosong Zhong ,&nbsp;Xiaotian Liu ,&nbsp;Hao Wang","doi":"10.1016/j.csr.2025.105574","DOIUrl":"10.1016/j.csr.2025.105574","url":null,"abstract":"<div><div>The interrelated biogeochemical cycles of silicon and carbon (Si-C) are essential for the effective functioning of aquatic ecosystems. However, there exists a notable gap in methodological research addressing the quantitative transport dynamics of Si-C within riverine systems. This study examines the spatiotemporal variations, sources, and export mechanisms of Si-C in the Changjiang and Yellow Rivers. Our results reveal that biogenic silica (BSi) concentrations are significantly affected by dam operations, while dissolved silicate (DSi) concentrations exhibit a modest downstream decline. Moreover, BSi associated with suspended particulate matter (SPM) shows an inverse relationship with SPM concentration. Particulate organic carbon (POC) in the Changjiang River predominantly originates from terrestrial C3 plants, whereas in the Yellow River, there is a greater contribution from C4 plants. Variations in the stoichiometric ratios of POC to nitrogen (C/N_bulk) and BSi suggest that carbon degradation during river transport is more pronounced than in estuarine environments. Additionally, the δ¹³C of bulk POC (δ¹³C_bulk) in the river exhibits greater sensitivity to environmental changes compared to the δ¹³C associated with BSi (δ¹³C_BSi). We propose a normalization-based methodology to assess the potential decay rates of POC and organic carbon associated with BSi within river systems. Carbon is more readily mineralized from particulate matter than from that associated with silicon, and the coupled Si-C dynamics can be employed to explore their differential behaviors and the role of silicon in carbon preservation. This study provides valuable insights into Si-C dynamics in river-estuary systems, particularly under the increasing influence of anthropogenic activities.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"295 ","pages":"Article 105574"},"PeriodicalIF":2.2,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145096250","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":"Shift in the phytoplankton composition associated with reversal in east India coastal currents in the Bay of Bengal","authors":"R. Sreevidhya,&nbsp;V.V.S.S. Sarma","doi":"10.1016/j.csr.2025.105566","DOIUrl":"10.1016/j.csr.2025.105566","url":null,"abstract":"<div><div>The alteration of phytoplankton composition due to variations in physical mixing, salinity, nutrient concentrations and their stoichiometric ratios would impact the overall ecosystem, affect the food web and influence the carbon cycle. The seasonal reversal in the East Indian Coastal Currents (EICC) significantly modifies stratification, physical mixing and nutrient levels in the coastal waters. To examine the impact of reversal in EICC on nutrient stoichiometry and phytoplankton composition, coastal waters were measured at a monthly time scale in the inshore and offshore regions of the Bay of Bengal for one year. The EICC flows northward between February and September, bringing saline waters along the coast, associated with winds from the south-west direction, promotes coastal upwelling. Elevated concentrations of nutrients (nitrate, phosphate and silicate) and phytoplankton biomass were observed associated with coastal upwelling dominated by fucoxanthin (Bacillariophyceae), and chlorophyll-b (Chl-b; green algae). CHEMTAX analysis suggests that diatoms contributed significantly (60–70 %) during the upwelling period, with up to 90 % of the contribution coming from microplankton in both coastal and offshore regions. The EICC reverses its flow towards the south between October and January, bringing low saline, nutrient-poor waters along the coast, resulting in a decrease in Chlorophyll-a (Chl-a). During this period, the coastal waters were dominated by zeaxanthin (cyanobacteria). Despite nutrients not being limiting, picoplankton dominance during this period is caused by the transport of cyanobacteria from the river to the coastal region due to their abundance in the river water. The CHEMTAX analysis suggested that diatoms, prochlorophytes, and cyanobacteria contributed significantly in the inshore region, whereas chlorophytes and cyanobacteria contributed to the offshore region. Picoplankton (&gt;50 %) contributed significantly, followed by micro (30 %) and nanoplankton (∼20 %). Fucoxanthin and Chl-b displayed a significant linear relationship with salinity, whereas zeaxanthin displayed an inverse relationship with salinity. The fraction of microplankton linearly correlated with salinity, whereas nano- and picoplankton inversely correlated. This study highlights the effect of temporal variabilities in salinity associated with reversing the EICC modified the phytoplankton composition, and it may have a significant impact on the coastal ecosystem. Understanding intra- and interannual variability in the EICC and associated salinity changes may allow for the prediction of phytoplankton composition in the coastal Bay of Bengal.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"295 ","pages":"Article 105566"},"PeriodicalIF":2.2,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145158153","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":"Association between selenium levels and the distribution of mangrove forests in the brackish water exchange zone of the Pearl river estuary","authors":"Zhenyan Zhang,&nbsp;Dan Su,&nbsp;Shuwen Xue,&nbsp;Jiaxuan Zhang,&nbsp;Jie Wang","doi":"10.1016/j.csr.2025.105573","DOIUrl":"10.1016/j.csr.2025.105573","url":null,"abstract":"<div><div>Mangroves are vital coastal wetland system widely distributed in tropical and subtropical intertidal zones around 30° latitude. In most coastal ecosystems, plant growth is generally inhibited by salinity. However, mangroves thrive in brackish coastal areas. Previous studies have shown that mangrove distribution is strongly influenced by seawater, likely due to its chemical composition and role in global biogeochemical cycles. Seasonal variations in salinity and selenium (Se) levels in coastal regions exhibit similar patterns, and low doses of supplemental Se can protect plants against reactive oxygen species (ROS)-induced oxidative damage. This study focused on the Pearl River Estuary to examine the relationship among Se content, salinity, and mangrove distribution. Clear seasonal fluctuations in Se levels were observed in the estuary. Se concentrations in the estuary were significantly higher than the average level due to runoff. Dissolved inorganic selenium (DISe) decreased with increasing distance from the estuary. Results revealed a significant positive correlation between mangrove distribution and Se content (<em>p</em> &lt; 0.05), whereas no significant relationship with salinity was found. Furthermore, Se application enhanced mangrove tolerance to salt stress-induced oxidative damage by strengthening antioxidant defense systems. These findings provide valuable insights for the conservation and management of mangrove ecosystems.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"295 ","pages":"Article 105573"},"PeriodicalIF":2.2,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145118582","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 fluxes in estuarine wetlands based on a material flow perspective","authors":"Bin Ji ,&nbsp;Huarui Li ,&nbsp;Haozhe Zhang ,&nbsp;Wenwen Li ,&nbsp;Qingjia Meng","doi":"10.1016/j.csr.2025.105571","DOIUrl":"10.1016/j.csr.2025.105571","url":null,"abstract":"<div><div>Estuarine wetland is important component of continental shelf and blue carbon system. The regulation and enhancement of the carbon pool in estuarine wetlands are contingent upon a clear understanding of the carbon cycle. Given that dynamic material flow is a landmark feature of estuarine wetlands, interpreting this process from a vertical and horizontal material flow perspective may offer a potential breakthrough. However, the impacts of the material exchange in estuaries on the key processes of carbon exchange in estuarine wetlands and the mechanism of carbon sink formation are not well understood. To accurately assess and predict the dynamic capacity of carbon pools in estuarine wetlands, this review summarizes the vertical carbon flux processes in estuarine wetlands, which are believed to be dominated by plant and soil material transport, as well as the horizontal carbon flux processes influenced by hydrological conditions. In addition, we discuss the impacts of carbon and nutrient fluxes from submarine groundwater discharge (SGD), which accompany estuarine wetlands, on the systematic carbon cycling. Finally, we offer a series of recommendations to bridge existing knowledge gaps and contribute to the broader scientific discourse on the carbon cycle in estuarine wetlands.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"295 ","pages":"Article 105571"},"PeriodicalIF":2.2,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145096247","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":"Ecological role and productive potential of a ∼30 years artificial reef - Southeastern Brazil","authors":"Igor David da Costa ,&nbsp;Ana Cristina Teixeira Bonecker ,&nbsp;Leonardo Lopes Costa ,&nbsp;Juliano Silva Lima ,&nbsp;Ilana Rosental Zalmon","doi":"10.1016/j.csr.2025.105572","DOIUrl":"10.1016/j.csr.2025.105572","url":null,"abstract":"<div><div>Artificial Reefs (ARs) increase the heterogeneity of areas that previously had homogeneous unconsolidated substrate, favoring the survival of juvenile fish by providing more anti-predation refuges. The efficacy of ARs to increase the abundance of fish and decrease the impacts of fisheries depends on their functionality as either attractors or producers of fish biomass. The present study sought to elucidate on the potential production role of a reef complex installed on the northern coast of Rio de Janeiro in 1996 besides the well-known attraction potential. Specifically, we aimed to compare the structure and composition of the ichthyoplankton community along a distance gradient from the ARs (0–1000 m). A total of 1941 ichthyoplankton specimens were sampled on dry and rainy seasons, including 13 families, 8 genera, and 11 species. During the rainy season, higher abundance of fish larvae was collected near the ARs, while in the dry season, ichthyoplankton was concentrated at greater distances from the reef complex. In both periods, fish eggs were mostly collected &lt;100 m from the ARs. Newly hatched larvae predominated at 1000 m distance, mainly during the rainy season. The number of larvae in the pre-flexion stage was predominant at 0 m, mainly during the rainy season. The presence of eggs and the predominance of pre-flexion larvae in areas closer to the reef modules indicate that this reef is an important spawning site for various fish species. The results reinforce spatial distribution characteristics of fish larvae in the ARs area, also suggesting that these structures initially acted as fish attractors but are now functioning as biomass producers for some species, including commercial ones. The ARs, being no-fishing zones, can be an effective tool both for fisheries management and biodiversity conservation.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"295 ","pages":"Article 105572"},"PeriodicalIF":2.2,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145059911","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}