Pub Date : 2025-11-21DOI: 10.1016/j.ecss.2025.109626
Abbasali Rahmani , Alessandro Stocchino
Microplastics are a pervasive marine pollutant, threatening coastal ecosystems and biodiversity. Understanding nearshore transport and dispersion is crucial for predicting microplastics’ fate and mitigating impacts. This study employs an Eulerian–Lagrangian model to simulate spherical microplastics, accounting for inertia and buoyancy, under regular and irregular waves in the nearshore region. Using realistic size–density distributions, the simulated particles range from non-buoyant to buoyant and from weakly to highly inertial. The shear layer, formed by Stokes drift and undertow, drives buoyant microplastics shoreward, controlling non-buoyant trajectories. The breaking region acts as a natural barrier, with few low-density, inertial particles passing through and potentially settling above the swash zone, while non-passing particles accumulate in the shoaling zone. Particle–wave characteristics are linked through dimensionless parameters, and we propose applicable dimensionless diffusive coefficients of and . Dispersion regimes transit from initial ballistic to subdiffusive within 10 wave periods. The subsequent superdiffusive regime is governed primarily by wave steepness and weakly by depth, particle density, and size. However, the absence of a sustained diffusive regime indicates diffusion coefficients may misestimate nearshore microplastic concentrations.
{"title":"Eulerian–Lagrangian simulation of wave-induced microplastic dispersion in nearshore zones: Processes and implications","authors":"Abbasali Rahmani , Alessandro Stocchino","doi":"10.1016/j.ecss.2025.109626","DOIUrl":"10.1016/j.ecss.2025.109626","url":null,"abstract":"<div><div>Microplastics are a pervasive marine pollutant, threatening coastal ecosystems and biodiversity. Understanding nearshore transport and dispersion is crucial for predicting microplastics’ fate and mitigating impacts. This study employs an Eulerian–Lagrangian model to simulate spherical microplastics, accounting for inertia and buoyancy, under regular and irregular waves in the nearshore region. Using realistic size–density distributions, the simulated particles range from non-buoyant to buoyant and from weakly to highly inertial. The shear layer, formed by Stokes drift and undertow, drives buoyant microplastics shoreward, controlling non-buoyant trajectories. The breaking region acts as a natural barrier, with few low-density, inertial particles passing through and potentially settling above the swash zone, while non-passing particles accumulate in the shoaling zone. Particle–wave characteristics are linked through dimensionless parameters, and we propose applicable dimensionless diffusive coefficients of <span><math><mrow><msubsup><mrow><mi>K</mi></mrow><mrow><mi>h</mi></mrow><mrow><mrow><mo>(</mo><mn>1</mn><mo>)</mo></mrow></mrow></msubsup><mi>T</mi><mo>/</mo><msubsup><mrow><mi>L</mi></mrow><mrow><mn>0</mn></mrow><mrow><mn>2</mn></mrow></msubsup><mo>≈</mo><mi>O</mi><mrow><mo>(</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>4</mn></mrow></msup><mo>)</mo></mrow></mrow></math></span> and <span><math><mrow><msubsup><mrow><mi>K</mi></mrow><mrow><mi>v</mi></mrow><mrow><mrow><mo>(</mo><mn>1</mn><mo>)</mo></mrow></mrow></msubsup><mi>T</mi><mo>/</mo><msubsup><mrow><mi>L</mi></mrow><mrow><mn>0</mn></mrow><mrow><mn>2</mn></mrow></msubsup><mo>≈</mo><mi>O</mi><mrow><mo>(</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>5</mn></mrow></msup><mo>)</mo></mrow></mrow></math></span>. Dispersion regimes transit from initial ballistic to subdiffusive within 10 wave periods. The subsequent superdiffusive regime is governed primarily by wave steepness and weakly by depth, particle density, and size. However, the absence of a sustained diffusive regime indicates diffusion coefficients may misestimate nearshore microplastic concentrations.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"328 ","pages":"Article 109626"},"PeriodicalIF":2.6,"publicationDate":"2025-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145579988","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}
Pub Date : 2025-11-21DOI: 10.1016/j.ecss.2025.109628
Xuebang Huang , Zengbin Sun , Yuping Luo , Xiujun Guo , Mingbo Li
The Laizhou Bay (LZB) in China, the world's largest coastal underground brine field, faces severe threats to its resource sustainability from intensive mining. Although previous studies have established that salt release from aquitards is a crucial source of brine salinity replenishment, continuous extraction has now triggered a concerning spatial redistribution of this salt reserve within the aquitards. Understanding this heterogeneity is therefore an urgent prerequisite for accurate resource assessment and effective management. To address this, we employed chloride (Cl−) as a conservative tracer to investigate the vertical salinity distribution in aquitards and identify the controlling factors. Cl− profiles from multiple sites across the 1300 km2 mining area were correlated with key parameters reflecting the paleo-depositional environment (hydrodynamic indices, grain-size parameters), sediment physical properties (hydraulic conductivity), and modern hydrodynamic conditions (dynamic water levels under pumping disturbance). Our integrated analysis, combining geochemistry, groundwater dynamics, and sediment dynamics, revealed a systematic spatial pattern: overall higher salinity in the west than in the east, with increasing salinity with depth in the east and the opposite trend in the west. Three primary factors control this heterogeneity: (1) Paleo-depositional environment: High-energy conditions in the east deposited well-sorted, coarse sediments facilitating leaching, unlike the fine-grained, poorly-sorted deposits in the west that restrict it; (2) Sediment permeability: High-permeability layers in the east enable efficient salt flushing, while low-permeability layers in the west hinder groundwater flow and salt transport; (3) Modern groundwater dynamics: Intensive pumping causes large water-level fluctuations (e.g., an amplitude of 11 m at borehole 7# in the eastern cone of depression), creating strong vertical Cl− gradients (up to 4.10 g/L/m) and enhancing leaching, whereas weaker dynamics slow release. This study provides the first systematic analysis of aquitard salinity heterogeneity and its controls in the LZB. The findings offer crucial scientific support for accurately assessing regional brine reserves, optimizing sustainable extraction strategies, and informing ecological conservation efforts.
{"title":"Spatial variability and controlling factors of residual salinity in aquitards of exploited coastal brine aquifers","authors":"Xuebang Huang , Zengbin Sun , Yuping Luo , Xiujun Guo , Mingbo Li","doi":"10.1016/j.ecss.2025.109628","DOIUrl":"10.1016/j.ecss.2025.109628","url":null,"abstract":"<div><div>The Laizhou Bay (LZB) in China, the world's largest coastal underground brine field, faces severe threats to its resource sustainability from intensive mining. Although previous studies have established that salt release from aquitards is a crucial source of brine salinity replenishment, continuous extraction has now triggered a concerning spatial redistribution of this salt reserve within the aquitards. Understanding this heterogeneity is therefore an urgent prerequisite for accurate resource assessment and effective management. To address this, we employed chloride (Cl<sup>−</sup>) as a conservative tracer to investigate the vertical salinity distribution in aquitards and identify the controlling factors. Cl<sup>−</sup> profiles from multiple sites across the 1300 km<sup>2</sup> mining area were correlated with key parameters reflecting the paleo-depositional environment (hydrodynamic indices, grain-size parameters), sediment physical properties (hydraulic conductivity), and modern hydrodynamic conditions (dynamic water levels under pumping disturbance). Our integrated analysis, combining geochemistry, groundwater dynamics, and sediment dynamics, revealed a systematic spatial pattern: overall higher salinity in the west than in the east, with increasing salinity with depth in the east and the opposite trend in the west. Three primary factors control this heterogeneity: (1) Paleo-depositional environment: High-energy conditions in the east deposited well-sorted, coarse sediments facilitating leaching, unlike the fine-grained, poorly-sorted deposits in the west that restrict it; (2) Sediment permeability: High-permeability layers in the east enable efficient salt flushing, while low-permeability layers in the west hinder groundwater flow and salt transport; (3) Modern groundwater dynamics: Intensive pumping causes large water-level fluctuations (e.g., an amplitude of 11 m at borehole 7# in the eastern cone of depression), creating strong vertical Cl<sup>−</sup> gradients (up to 4.10 g/L/m) and enhancing leaching, whereas weaker dynamics slow release. This study provides the first systematic analysis of aquitard salinity heterogeneity and its controls in the LZB. The findings offer crucial scientific support for accurately assessing regional brine reserves, optimizing sustainable extraction strategies, and informing ecological conservation efforts.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"329 ","pages":"Article 109628"},"PeriodicalIF":2.6,"publicationDate":"2025-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145610292","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}
Pub Date : 2025-11-20DOI: 10.1016/j.ecss.2025.109625
Wei Guo , Jie Feng , Haiyan Wang , Zhen Zhang , Shuang Liang , Tao Zhang , Haolin Yu
Marine ranching, which are artificially constructed nearshore ecosystems, increase carbon sequestration efficiency through bioremediation techniques such as stock enhancement and artificial reef deployment. Marine ranching enhances carbon sequestration but lacks robust evaluation methods. This article first develops a transferable framework for evaluating carbon sequestration in marine ranching by integrating ecosystem carbon budgets, dynamic carbon cycling, and the effects of species enhancement and fisheries management, and then applies this framework to the Beibu Gulf to demonstrate its generalisability and to identify the primary drivers. Based on field survey data, were developed Ecopath carbon mass models for a marine ranching and a nearby control area and fitted Ecosim models to simulate 12 stock enhancement-fishing scenarios combined with logarithmic mean Divisia index (LMDI) analysis. The results revealed that current artificial reef deployment increased the carbon flux and total carbon sequestration in the marine ranching area by 2.52 and 3.43 times compared with those in the control area, respectively. The “Mytilus + fishing” scenario (releasing Mytilus while maintaining current fishing) was simulated to achieve a high peak carbon sequestration efficiency of 2.21 times that of the baseline scenario. LMDI analysis revealed that expansion of the biomass scale compared to the community structure was the primary driver of carbon sequestration in all scenarios (>90.99 % contribution). Given the growing need for fisheries management to incorporate carbon sequestration considerations, particularly in marine ranching and other coastal ecosystems, the paper conclude by discussing the strengths and potential limitations of this framework and suggest directions for future development.
{"title":"Evaluating bio-carbon sequestration in Beibu Gulf marine ranching areas via EwE modelling and LMDI analysis","authors":"Wei Guo , Jie Feng , Haiyan Wang , Zhen Zhang , Shuang Liang , Tao Zhang , Haolin Yu","doi":"10.1016/j.ecss.2025.109625","DOIUrl":"10.1016/j.ecss.2025.109625","url":null,"abstract":"<div><div>Marine ranching, which are artificially constructed nearshore ecosystems, increase carbon sequestration efficiency through bioremediation techniques such as stock enhancement and artificial reef deployment. Marine ranching enhances carbon sequestration but lacks robust evaluation methods. This article first develops a transferable framework for evaluating carbon sequestration in marine ranching by integrating ecosystem carbon budgets, dynamic carbon cycling, and the effects of species enhancement and fisheries management, and then applies this framework to the Beibu Gulf to demonstrate its generalisability and to identify the primary drivers. Based on field survey data, were developed Ecopath carbon mass models for a marine ranching and a nearby control area and fitted Ecosim models to simulate 12 stock enhancement-fishing scenarios combined with logarithmic mean Divisia index (LMDI) analysis. The results revealed that current artificial reef deployment increased the carbon flux and total carbon sequestration in the marine ranching area by 2.52 and 3.43 times compared with those in the control area, respectively. The “Mytilus + fishing” scenario (releasing Mytilus while maintaining current fishing) was simulated to achieve a high peak carbon sequestration efficiency of 2.21 times that of the baseline scenario. LMDI analysis revealed that expansion of the biomass scale compared to the community structure was the primary driver of carbon sequestration in all scenarios (>90.99 % contribution). Given the growing need for fisheries management to incorporate carbon sequestration considerations, particularly in marine ranching and other coastal ecosystems, the paper conclude by discussing the strengths and potential limitations of this framework and suggest directions for future development.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"328 ","pages":"Article 109625"},"PeriodicalIF":2.6,"publicationDate":"2025-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145624739","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}
Pub Date : 2025-11-19DOI: 10.1016/j.ecss.2025.109612
D. Escobar-Ortega , L. Couceiro , A. Fernández-Piñeiro , P. Seoane , D. Fernández-Márquez , R. Muíño , N. Fernández
Understanding reproductive cycles is essential for the sustainable management of marine resources, particularly those of exploited yet understudied invertebrates such as the polychaete Scoletoma laurentiana, a key bait species in Galicia (NW Spain). This study provides the first detailed description of its reproductive cycle in temperate Atlantic waters, focusing on seasonal dynamics and environmental drivers. Monthly samples collected during 2021 and 2023 at three coastal sites were analyzed through image-based quantification of oocyte size in relation to seawater temperature and photoperiod. The results revealed synchronous oogenic development at the individual level but asynchronous at the population scale, indicating extended spawning periods. Oogenesis began in late autumn, peaked in spring, and ceased completely during summer. Overall mean oocyte diameter was 172.27 μm ± 22.52, with significant spatial and interannual differences indicating reproductive plasticity. A strong inverse correlation between seawater temperature and the proportion of ovigerous females confirmed temperature as the main driver of spawning initiation, whereas photoperiod showed no significant effect. These findings provide the first comprehensive evidence of temperature-mediated reproductive seasonality in S. laurentiana, offering critical baseline knowledge for the sustainable management of this species in the northeastern Atlantic. Furthermore, the results indicate that the species productivity may be subject to alteration in response to climate change.
{"title":"Reproductive dynamics of Scoletoma laurentiana (Polychaeta: Lumbrineridae) in NW Spain: Temperature-driven seasonal trends","authors":"D. Escobar-Ortega , L. Couceiro , A. Fernández-Piñeiro , P. Seoane , D. Fernández-Márquez , R. Muíño , N. Fernández","doi":"10.1016/j.ecss.2025.109612","DOIUrl":"10.1016/j.ecss.2025.109612","url":null,"abstract":"<div><div>Understanding reproductive cycles is essential for the sustainable management of marine resources, particularly those of exploited yet understudied invertebrates such as the polychaete <em>Scoletoma laurentiana</em>, a key bait species in Galicia (NW Spain). This study provides the first detailed description of its reproductive cycle in temperate Atlantic waters, focusing on seasonal dynamics and environmental drivers. Monthly samples collected during 2021 and 2023 at three coastal sites were analyzed through image-based quantification of oocyte size in relation to seawater temperature and photoperiod. The results revealed synchronous oogenic development at the individual level but asynchronous at the population scale, indicating extended spawning periods. Oogenesis began in late autumn, peaked in spring, and ceased completely during summer. Overall mean oocyte diameter was 172.27 μm ± 22.52, with significant spatial and interannual differences indicating reproductive plasticity. A strong inverse correlation between seawater temperature and the proportion of ovigerous females confirmed temperature as the main driver of spawning initiation, whereas photoperiod showed no significant effect. These findings provide the first comprehensive evidence of temperature-mediated reproductive seasonality in <em>S. laurentiana,</em> offering critical baseline knowledge for the sustainable management of this species in the northeastern Atlantic. Furthermore, the results indicate that the species productivity may be subject to alteration in response to climate change.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"328 ","pages":"Article 109612"},"PeriodicalIF":2.6,"publicationDate":"2025-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145624716","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}
Pub Date : 2025-11-14DOI: 10.1016/j.ecss.2025.109624
Jie Feng , Qian Yu , Shiyi Cao , Zhiyun Du , Hangjie Lin , Ya Ping Wang , Yunwei Wang
Estuarine turbidity maximum zones (ETMs) exhibit significant spring-neap and seasonal variations. Quantifying these dynamics from sparse, long-term remote sensing data is crucial for understanding ETM evolution. Using hourly GOCI satellite imagery (2011–2021) from the Yangtze Estuary, we applied Lomb-Scargle periodogram and phase-folded methods to extract the horizontal movement characteristics (amplitude and phase) of the ETM, tracked via 150, 100, and 50 mg/L SSC isolines. We found that the ETM extent has obvious spring-neap variations that lag the tidal cycle. Notably, high-SSC regions showed heightened sensitivity to tidal forcing: the 150 mg/L isoline had a larger amplitude (5.05 km) and shorter lag (1.42 days) compared to the 50 mg/L isoline (4.29 km amplitude, 1.99-day lag). Both amplitude and phase also exhibited significant seasonality. The phase lag proved highly sensitive to these seasonal changes: it was most pronounced in summer (a 2.44-day lag), decreased in spring (1.32 days) and autumn (0.65 days), and became a slight phase lead in winter (−0.13 days). These seasonal dynamics are linked to variations in sediment supply, waves, and river discharge. This study's approach provides a robust framework for extracting ETM spring-neap characteristics from sparse satellite data, clarifying multi-timescale ETM responses for similar estuarine studies.
{"title":"Seasonal modulation of the spring-neap response of Yangtze Estuary turbidity maximum: Movement, amplitude, and phase lag via remote sensing","authors":"Jie Feng , Qian Yu , Shiyi Cao , Zhiyun Du , Hangjie Lin , Ya Ping Wang , Yunwei Wang","doi":"10.1016/j.ecss.2025.109624","DOIUrl":"10.1016/j.ecss.2025.109624","url":null,"abstract":"<div><div>Estuarine turbidity maximum zones (ETMs) exhibit significant spring-neap and seasonal variations. Quantifying these dynamics from sparse, long-term remote sensing data is crucial for understanding ETM evolution. Using hourly GOCI satellite imagery (2011–2021) from the Yangtze Estuary, we applied Lomb-Scargle periodogram and phase-folded methods to extract the horizontal movement characteristics (amplitude and phase) of the ETM, tracked via 150, 100, and 50 mg/L SSC isolines. We found that the ETM extent has obvious spring-neap variations that lag the tidal cycle. Notably, high-SSC regions showed heightened sensitivity to tidal forcing: the 150 mg/L isoline had a larger amplitude (5.05 km) and shorter lag (1.42 days) compared to the 50 mg/L isoline (4.29 km amplitude, 1.99-day lag). Both amplitude and phase also exhibited significant seasonality. The phase lag proved highly sensitive to these seasonal changes: it was most pronounced in summer (a 2.44-day lag), decreased in spring (1.32 days) and autumn (0.65 days), and became a slight phase lead in winter (−0.13 days). These seasonal dynamics are linked to variations in sediment supply, waves, and river discharge. This study's approach provides a robust framework for extracting ETM spring-neap characteristics from sparse satellite data, clarifying multi-timescale ETM responses for similar estuarine studies.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"328 ","pages":"Article 109624"},"PeriodicalIF":2.6,"publicationDate":"2025-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145579985","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}
Pub Date : 2025-11-14DOI: 10.1016/j.ecss.2025.109597
Ana Beatriz Moreira Ferreira-Ramos , Virág Venekey , Thuareag Monteiro Trindade dos Santos
This study compares, for the first time, the temporal variations in the structure of meiofauna community, with emphasis in nematodes, between areas with or without presence of the Aninga macrophyte (M. linifera) in an urban Amazonian estuary. For this purpose, monthly samplings were carried during one year, divided into four climatic periods (Transition 1, Dry, Transition 2 and Rainy), in areas with and without vegetation in the Guajará River estuary, North Brazil. The two environments showed a similar granulometric composition comparing periods, mainly composed by fine sediments. Organic matter showed similar values throughout periods, with the highest concentration during Transition 1 (T1). Meiofauna was represented by 12 groups, with Nematoda as the most abundant group during all study. Density showed highest values during T1, while richness was highest during the dry and T2 periods. Nematoda was composed by 89 genera belonging to 39 families, with Zygonemella as the most abundant genus, belonging to Xyalidae, the most abundant and richest family. The highest density and richness of genera occurred during the T2 period in the vegetated environment. Overall, this study showed that both meiofauna and nematodes were influenced by the seasonality of rainfall, the amount of nutrients available in the sediment and also by the presence of vegetation.
{"title":"How vegetation of Aninga (Montrichardia linifera) shapes meiofauna and nematoda in an urban Amazonian estuary?","authors":"Ana Beatriz Moreira Ferreira-Ramos , Virág Venekey , Thuareag Monteiro Trindade dos Santos","doi":"10.1016/j.ecss.2025.109597","DOIUrl":"10.1016/j.ecss.2025.109597","url":null,"abstract":"<div><div>This study compares, for the first time, the temporal variations in the structure of meiofauna community, with emphasis in nematodes, between areas with or without presence of the Aninga macrophyte (<em>M. linifera</em>) in an urban Amazonian estuary. For this purpose, monthly samplings were carried during one year, divided into four climatic periods (Transition 1, Dry, Transition 2 and Rainy), in areas with and without vegetation in the Guajará River estuary, North Brazil. The two environments showed a similar granulometric composition comparing periods, mainly composed by fine sediments. Organic matter showed similar values throughout periods, with the highest concentration during Transition 1 (T1). Meiofauna was represented by 12 groups, with Nematoda as the most abundant group during all study. Density showed highest values during T1, while richness was highest during the dry and T2 periods. Nematoda was composed by 89 genera belonging to 39 families, with <em>Zygonemella</em> as the most abundant genus, belonging to Xyalidae, the most abundant and richest family. The highest density and richness of genera occurred during the T2 period in the vegetated environment. Overall, this study showed that both meiofauna and nematodes were influenced by the seasonality of rainfall, the amount of nutrients available in the sediment and also by the presence of vegetation.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"328 ","pages":"Article 109597"},"PeriodicalIF":2.6,"publicationDate":"2025-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145624792","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}
Pub Date : 2025-11-12DOI: 10.1016/j.ecss.2025.109611
E. Ovsyanikova , W.N. Venables , J.W. Udy
Seagrasses are essential for coastal carbon sequestration and the survival of marine fauna worldwide. Regular seagrass monitoring is essential for coastal conservation as such areas are susceptible to rapid decline usually due to anthropogenic influence. We used long-term (2015–2021) supervised citizen science data collected in Moreton Bay (Quandamooka), Australia, to investigate temporal change over a seven-year period and developed a random forest seagrass distribution model, using depth, water quality, and other predictor variables. We used hierarchical clustering to define seagrass groupings, which resulted in five clusters, named after the dominant seagrass species: ‘OS’ (Oceana serrulata), ‘ZM’ (Zostera muelleri), ‘HS’ (Halophila spinulosa), ‘HO’ (Halophila ovalis), and ‘Sparse’, the cluster with little or no seagrass present. To investigate temporal change in seagrass meadows during our study period, we conducted a longitudinal analysis of overall seagrass cover and seagrass cluster dominance using areas that had a sufficient number of samples in at least three consecutive time periods.
The predictive model produced a probability map of seagrass occurrence in Moreton Bay, explaining 86.7 % of the variability. It highlighted areas of the bay that would suffer from continuing water quality decline. Longitudinal analysis showed a decrease in seagrass presence in shallow water areas, of several areas of the bay across the study period (2015–2021), and changes in seagrass community composition across the bay.
Our results demonstrate the effective use of citizen science-collected data and statistical modelling techniques to understand the spatial and temporal variability of seagrass communities.
{"title":"Spatial and temporal modelling of seagrass distribution in Moreton Bay, Australia, based on long-term citizen science data","authors":"E. Ovsyanikova , W.N. Venables , J.W. Udy","doi":"10.1016/j.ecss.2025.109611","DOIUrl":"10.1016/j.ecss.2025.109611","url":null,"abstract":"<div><div>Seagrasses are essential for coastal carbon sequestration and the survival of marine fauna worldwide. Regular seagrass monitoring is essential for coastal conservation as such areas are susceptible to rapid decline usually due to anthropogenic influence. We used long-term (2015–2021) supervised citizen science data collected in Moreton Bay (Quandamooka), Australia, to investigate temporal change over a seven-year period and developed a random forest seagrass distribution model, using depth, water quality, and other predictor variables. We used hierarchical clustering to define seagrass groupings, which resulted in five clusters, named after the dominant seagrass species: ‘OS’ (<em>Oceana serrulata</em>), ‘ZM’ (<em>Zostera muelleri</em>), ‘HS’ (<em>Halophila spinulosa</em>), ‘HO’ (<em>Halophila ovalis</em>), and ‘Sparse’, the cluster with little or no seagrass present. To investigate temporal change in seagrass meadows during our study period, we conducted a longitudinal analysis of overall seagrass cover and seagrass cluster dominance using areas that had a sufficient number of samples in at least three consecutive time periods.</div><div>The predictive model produced a probability map of seagrass occurrence in Moreton Bay, explaining 86.7 % of the variability. It highlighted areas of the bay that would suffer from continuing water quality decline. Longitudinal analysis showed a decrease in seagrass presence in shallow water areas, of several areas of the bay across the study period (2015–2021), and changes in seagrass community composition across the bay.</div><div>Our results demonstrate the effective use of citizen science-collected data and statistical modelling techniques to understand the spatial and temporal variability of seagrass communities.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"328 ","pages":"Article 109611"},"PeriodicalIF":2.6,"publicationDate":"2025-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145579987","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}
Pub Date : 2025-11-12DOI: 10.1016/j.ecss.2025.109606
Hoi-Soo Jung , Keunyong Kim , Junho Lee , Joo-hyung Ryu , Hanjun Woo
Tidal meanders, comprising large-scale channels, medium-sized creeks, and small-sized gullies, serve as critical lifelines supporting tidal flat ecosystems. While extensive research has been conducted on vegetated meanders in terrestrial and coastal environments, the morphodynamics of tidal meanders in non-vegetated tidal flats, particularly those influenced by monsoonal climates, remain poorly explored. This study investigates the migration dynamics of tidal meanders across three distinct non-vegetated tidal flats along the west coast of Korea, each differing in tidal range, embayment geometry, and surrounding topography. Based on over a decade of Google Earth imagery, migration rates were analyzed according to meander size. The results reveal that smaller meanders exhibit faster migration rates when normalized by channel width. Furthermore, the migration rates of tidal meanders in non-vegetated flats were found to be approximately an order of magnitude higher than those reported in the literature for vegetated environments such as salt marshes. The results also highlight significant differences in migration rates among the analyzed tidal flats, driven primarily by variations in tidal range and exposure to the northwesterly East Asian Winter Monsoon. These findings highlight the complex interactions between hydrodynamic, climatic and geomorphological factors in the dynamic evolution of tidal flat meanders.
{"title":"Factors constraining the morphodynamics of tidal meanders in non-vegetated tidal flats under a monsoon climate","authors":"Hoi-Soo Jung , Keunyong Kim , Junho Lee , Joo-hyung Ryu , Hanjun Woo","doi":"10.1016/j.ecss.2025.109606","DOIUrl":"10.1016/j.ecss.2025.109606","url":null,"abstract":"<div><div>Tidal meanders, comprising large-scale channels, medium-sized creeks, and small-sized gullies, serve as critical lifelines supporting tidal flat ecosystems. While extensive research has been conducted on vegetated meanders in terrestrial and coastal environments, the morphodynamics of tidal meanders in non-vegetated tidal flats, particularly those influenced by monsoonal climates, remain poorly explored. This study investigates the migration dynamics of tidal meanders across three distinct non-vegetated tidal flats along the west coast of Korea, each differing in tidal range, embayment geometry, and surrounding topography. Based on over a decade of Google Earth imagery, migration rates were analyzed according to meander size. The results reveal that smaller meanders exhibit faster migration rates when normalized by channel width. Furthermore, the migration rates of tidal meanders in non-vegetated flats were found to be approximately an order of magnitude higher than those reported in the literature for vegetated environments such as salt marshes. The results also highlight significant differences in migration rates among the analyzed tidal flats, driven primarily by variations in tidal range and exposure to the northwesterly East Asian Winter Monsoon. These findings highlight the complex interactions between hydrodynamic, climatic and geomorphological factors in the dynamic evolution of tidal flat meanders.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"328 ","pages":"Article 109606"},"PeriodicalIF":2.6,"publicationDate":"2025-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145529376","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}
Pub Date : 2025-11-11DOI: 10.1016/j.ecss.2025.109594
Jing Han , Lin Sun , Junrong Liang , Yahui Gao , Changping Chen
This study investigated benthic microeukaryotic communities in four intertidal salt marsh habitats (Phragmites australis, Suaeda salsa, Tamarix chinensis, and unvegetated mudflat) in the Yellow River Estuary during summer and winter. High-throughput sequencing of the 18S rRNA gene was employed to profile the communities, with a specific focus on the role of microalgae in sediment carbon sequestration. The results showed that benthic microeukaryotic communities were significantly influenced by seasons, habitats, and various environmental factors. Overall biodiversity was higher in winter, whereas the α-diversity index in summer exhibited a significant positive correlation with sediment carbon and nitrogen contents (p < 0.01). The results also suggested that biodiversity might be negatively correlated with sediment particle size to some extent. Notably, the Phragmites australis habitat exhibited distinct species richness and community composition relative to the other three habitats. Sediment carbon and nitrogen contents displayed distinct seasonal variations, with significantly higher concentrations in summer than in winter (p < 0.05). Furthermore, microalgae (e.g., Bacillariophyta and Chlorophyta) were important components of the benthic microeukaryotic community and were suggested to be key contributors to sediment organic matter. Based on these findings, we suggest that increased microalgal abundance may not only enhance interactions among community members but also facilitate the accumulation of organic carbon and nitrogen in intertidal sediments.
{"title":"Characteristics of benthic microeukaryotic communities in different ecosystems of the Yellow River Estuary salt marshes","authors":"Jing Han , Lin Sun , Junrong Liang , Yahui Gao , Changping Chen","doi":"10.1016/j.ecss.2025.109594","DOIUrl":"10.1016/j.ecss.2025.109594","url":null,"abstract":"<div><div>This study investigated benthic microeukaryotic communities in four intertidal salt marsh habitats (<em>Phragmites australis</em>, <em>Suaeda salsa</em>, <em>Tamarix chinensis</em>, and unvegetated mudflat) in the Yellow River Estuary during summer and winter. High-throughput sequencing of the 18S rRNA gene was employed to profile the communities, with a specific focus on the role of microalgae in sediment carbon sequestration. The results showed that benthic microeukaryotic communities were significantly influenced by seasons, habitats, and various environmental factors. Overall biodiversity was higher in winter, whereas the α-diversity index in summer exhibited a significant positive correlation with sediment carbon and nitrogen contents (p < 0.01). The results also suggested that biodiversity might be negatively correlated with sediment particle size to some extent. Notably, the <em>Phragmites australis</em> habitat exhibited distinct species richness and community composition relative to the other three habitats. Sediment carbon and nitrogen contents displayed distinct seasonal variations, with significantly higher concentrations in summer than in winter (p < 0.05). Furthermore, microalgae (e.g., Bacillariophyta and Chlorophyta) were important components of the benthic microeukaryotic community and were suggested to be key contributors to sediment organic matter. Based on these findings, we suggest that increased microalgal abundance may not only enhance interactions among community members but also facilitate the accumulation of organic carbon and nitrogen in intertidal sediments.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"328 ","pages":"Article 109594"},"PeriodicalIF":2.6,"publicationDate":"2025-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145529377","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}
Pub Date : 2025-11-10DOI: 10.1016/j.ecss.2025.109608
Ligia Salgado Bechara , Rafael Duarte Monteiro , Gustavo Mattos , Arthur Bauer , Pedro Vianna Gatts , Maurício Mussi Molisani , Luciano Gomes Fischer , Carlos Eduardo Rezende , Yasmina Esmaeili , Patrícia Luciano Mancini , Carlos Alberto Barboza
The ghost crab species Ocypode quadrata is a key crustacean inhabitant of sandy beaches along the Western Atlantic coast, playing a crucial role in beach food webs. In this study, we describe and compare the trophic ecology of O. quadrata on beaches with varying levels of urbanization in Rio de Janeiro, Brazil. We utilized a combination of stomach content analysis (frequency of occurrence, FO%) and stable isotope analysis of δ15N and δ13C (isotopic niche and mixing models) in O. quadrata and their primary prey sources. Our results indicated that both marine and terrestrial sources play key roles in the trophic ecology of the ghost crab Ocypode quadrata, highlighting its function in energy transfer across coastal ecosystems. Although no differences were found in assimilated food proportions between urbanized and non-urbanized beaches, broader isotopic niches on less urbanized areas suggest that natural habitat modification may constrain the species’ trophic niche. Isotopic niche breadths indicated similar dietary patterns and habitat use across beaches, though individuals from low urbanized areas exhibited broader niches, suggesting greater resource diversity use. We observed high isotopic niche overlap (>50 %), with a nested pattern where the low urbanized sector encompassed the dietary niches of urbanized ones. Conversely, mixing models highlighted a greater assimilation of Emerita brasiliensis across all beaches, emphasizing a preference for high-calorie food sources when available. Higher δ13C values further supported an association with marine-derived resources. The trophic ecology of O. quadrata offers valuable insights into the connectivity between biological complexes and adjacent ecosystems, contributing to a landscape approach.
{"title":"Linking the trophodynamics of the ghost crab Ocypode quadrata (Fabricius, 1787) to natural habitat modification on sandy beaches","authors":"Ligia Salgado Bechara , Rafael Duarte Monteiro , Gustavo Mattos , Arthur Bauer , Pedro Vianna Gatts , Maurício Mussi Molisani , Luciano Gomes Fischer , Carlos Eduardo Rezende , Yasmina Esmaeili , Patrícia Luciano Mancini , Carlos Alberto Barboza","doi":"10.1016/j.ecss.2025.109608","DOIUrl":"10.1016/j.ecss.2025.109608","url":null,"abstract":"<div><div>The ghost crab species <em>Ocypode quadrata</em> is a key crustacean inhabitant of sandy beaches along the Western Atlantic coast, playing a crucial role in beach food webs. In this study, we describe and compare the trophic ecology of <em>O. quadrata</em> on beaches with varying levels of urbanization in Rio de Janeiro, Brazil. We utilized a combination of stomach content analysis (frequency of occurrence, FO%) and stable isotope analysis of <em>δ</em><sup>15</sup>N and <em>δ</em><sup>13</sup>C (isotopic niche and mixing models) in <em>O. quadrata</em> and their primary prey sources. Our results indicated that both marine and terrestrial sources play key roles in the trophic ecology of the ghost crab <em>Ocypode quadrata</em>, highlighting its function in energy transfer across coastal ecosystems. Although no differences were found in assimilated food proportions between urbanized and non-urbanized beaches, broader isotopic niches on less urbanized areas suggest that natural habitat modification may constrain the species’ trophic niche. Isotopic niche breadths indicated similar dietary patterns and habitat use across beaches, though individuals from low urbanized areas exhibited broader niches, suggesting greater resource diversity use. We observed high isotopic niche overlap (>50 %), with a nested pattern where the low urbanized sector encompassed the dietary niches of urbanized ones. Conversely, mixing models highlighted a greater assimilation of <em>Emerita brasiliensis</em> across all beaches, emphasizing a preference for high-calorie food sources when available. Higher <em>δ</em><sup>13</sup>C values further supported an association with marine-derived resources. The trophic ecology of <em>O. quadrata</em> offers valuable insights into the connectivity between biological complexes and adjacent ecosystems, contributing to a landscape approach.</div></div>","PeriodicalId":50497,"journal":{"name":"Estuarine Coastal and Shelf Science","volume":"328 ","pages":"Article 109608"},"PeriodicalIF":2.6,"publicationDate":"2025-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145579986","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}
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