Pub Date : 2025-12-06DOI: 10.1016/j.csr.2025.105622
Paula Birocchi , Marcelo Dottori , Leticia Fabre-Lima , Carine de Godoi Rezende Costa , José Roberto Bairão Leite , Dalton Kei Sasaki , Robert James Chant
<div><div>Climate change has the potential to alter the rainfall regimes in South America (SA), which can affect the local river discharge and disturb estuarine environments. Thus, understanding the water flux variability under climate change and the influence of extreme events in a complex estuary is relevant to prevent and mitigate future negative impacts. Here we quantified the water flux to understand potential changes in estuaries and focus on investigating the variability of river discharge under both present and future climate projections, while also considering the effects of extreme events such as storm tides and atmospheric blocking. The Cananéia-Iguape estuarine-lagoon complex (CIELC), situated in the South Brazil Bight (SBB), was chosen as an example to apply the method. It has two inlets, a dominant source of river discharge (Valo Grande Channel, VGC), and smaller tributaries. The water flux was calculated with numerical simulations for three estuarine cross-sections by integrating the fluxes through them. The experiments were performed using a hydrodynamic numerical model and its results were validated. Validation parameter values ranged from 0.80 to 0.94 for salinity, 0.57 to 0.84 for currents, and 0.93 for total sea level. The modeled sea level was used to classify the area of study as hypersynchronous, with tidal amplitudes increasing upstream. For the climate change scenarios, we found that a decrease in precipitation of 5% (September SSP126) and 25% (September SSP585), and an increase of 5% (June SSP126) and 15% (June SSP585) in the rainfall, and consequently, in the river discharge, caused statistically significant changes in the water flux. Higher water fluxes were found during periods of stronger river discharge, particularly during the anomalous storm tide of August 2016, when intense rainfall was present. Since this estuary dynamics is dominated by tides, we compared the future scenarios of water fluxes considering neap and spring, and between ebb and flood tides. Water flow increased during the spring in comparison to the neap tide by approximately 7%, 5%, and 1%, in the northern, southern inlets, and the VGC cross-sections, respectively. The ebb tidal fluxes, with a mean value of approximately 163 m<span><math><msup><mrow></mrow><mrow><mn>3</mn></mrow></msup></math></span> s<span><math><msup><mrow></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></math></span> were 24% significantly stronger (<span><math><mi>p</mi></math></span>-value <span><math><mo><</mo></math></span>0.05) than the flood, which presented a mean value of 124 m<span><math><msup><mrow></mrow><mrow><mn>3</mn></mrow></msup></math></span> s<span><math><msup><mrow></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></math></span>. Both inlets showed faster ebb periods, with mean values of 6.14 and 5.98 h, in comparison to the flood of 6.25 and 6.41 h, respectively. We quantified the water flux percentage in each tributary connected to the main estuarine channel,
气候变化有可能改变南美洲（SA）的降雨制度，这可能影响当地河流流量并扰乱河口环境。因此，了解气候变化和极端事件对复杂河口水通量的影响对预防和减轻未来的负面影响具有重要意义。在这里，我们量化了水通量以了解河口的潜在变化，并重点研究了当前和未来气候预测下河流流量的变异性，同时也考虑了极端事件（如风暴潮和大气阻塞）的影响。位于南巴西湾（SBB）的canan - iguape河口-泻湖综合体（CIELC）被选为应用该方法的例子。它有两个入口，一个主要的河流排放源（Valo Grande Channel， VGC）和较小的支流。对三个河口断面的水流通量进行了数值模拟，计算了水流通量。利用水动力数值模型进行了实验，并对实验结果进行了验证。盐度验证参数值为0.80 ~ 0.94，海流验证参数值为0.57 ~ 0.84，总海平面验证参数值为0.93。利用模拟的海平面将研究区域划分为超同步，潮汐振幅在上游增加。在气候变化情景下，降水量减少5%（9月SSP126）和25%(9月SSP585)，降雨量增加5%（6月SSP126）和15%(6月SSP585)，从而引起河流量的显著变化。在河流流量较强的时期，特别是2016年8月异常风暴潮期间，发现了较高的水通量，当时出现了强降雨。由于该河口动态受潮汐控制，我们比较了考虑小潮和大潮以及退潮和涨潮的未来水通量情景。与小潮相比，春季北部、南部入海口和VGC断面的水流量分别增加了约7%、5%和1%。退潮通量均值约为163 m3 s - 1，比洪潮通量均值124 m3 s - 1强24% （p值<；0.05）。两个进水口的平均退潮时间分别为6.14和5.98 h，而洪水的平均退潮时间分别为6.25和6.41 h。考虑到所有研究情景，我们量化了与主要河口通道相连的每条支流的水通量百分比。总体而言，北部入口被确定为主要的水运通道，约占整个河口的总流量的68.2%。该研究揭示了亚热带河口-泻湖综合体水通量动态的未来和极端条件，对气候变化条件下的可持续水管理战略至关重要。
{"title":"Water flux quantification in a subtropical estuary through numerical modeling","authors":"Paula Birocchi , Marcelo Dottori , Leticia Fabre-Lima , Carine de Godoi Rezende Costa , José Roberto Bairão Leite , Dalton Kei Sasaki , Robert James Chant","doi":"10.1016/j.csr.2025.105622","DOIUrl":"10.1016/j.csr.2025.105622","url":null,"abstract":"<div><div>Climate change has the potential to alter the rainfall regimes in South America (SA), which can affect the local river discharge and disturb estuarine environments. Thus, understanding the water flux variability under climate change and the influence of extreme events in a complex estuary is relevant to prevent and mitigate future negative impacts. Here we quantified the water flux to understand potential changes in estuaries and focus on investigating the variability of river discharge under both present and future climate projections, while also considering the effects of extreme events such as storm tides and atmospheric blocking. The Cananéia-Iguape estuarine-lagoon complex (CIELC), situated in the South Brazil Bight (SBB), was chosen as an example to apply the method. It has two inlets, a dominant source of river discharge (Valo Grande Channel, VGC), and smaller tributaries. The water flux was calculated with numerical simulations for three estuarine cross-sections by integrating the fluxes through them. The experiments were performed using a hydrodynamic numerical model and its results were validated. Validation parameter values ranged from 0.80 to 0.94 for salinity, 0.57 to 0.84 for currents, and 0.93 for total sea level. The modeled sea level was used to classify the area of study as hypersynchronous, with tidal amplitudes increasing upstream. For the climate change scenarios, we found that a decrease in precipitation of 5% (September SSP126) and 25% (September SSP585), and an increase of 5% (June SSP126) and 15% (June SSP585) in the rainfall, and consequently, in the river discharge, caused statistically significant changes in the water flux. Higher water fluxes were found during periods of stronger river discharge, particularly during the anomalous storm tide of August 2016, when intense rainfall was present. Since this estuary dynamics is dominated by tides, we compared the future scenarios of water fluxes considering neap and spring, and between ebb and flood tides. Water flow increased during the spring in comparison to the neap tide by approximately 7%, 5%, and 1%, in the northern, southern inlets, and the VGC cross-sections, respectively. The ebb tidal fluxes, with a mean value of approximately 163 m<span><math><msup><mrow></mrow><mrow><mn>3</mn></mrow></msup></math></span> s<span><math><msup><mrow></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></math></span> were 24% significantly stronger (<span><math><mi>p</mi></math></span>-value <span><math><mo><</mo></math></span>0.05) than the flood, which presented a mean value of 124 m<span><math><msup><mrow></mrow><mrow><mn>3</mn></mrow></msup></math></span> s<span><math><msup><mrow></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></math></span>. Both inlets showed faster ebb periods, with mean values of 6.14 and 5.98 h, in comparison to the flood of 6.25 and 6.41 h, respectively. We quantified the water flux percentage in each tributary connected to the main estuarine channel,","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"297 ","pages":"Article 105622"},"PeriodicalIF":2.2,"publicationDate":"2025-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145790240","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 : 2025-12-05DOI: 10.1016/j.csr.2025.105623
Maciej Chelchowski, Piotr Balazy, Piotr Kuklinski
The incessantly disturbed Antarctic intertidal zone is currently facing additional challenges associated with climate change, such as warming and increased meltwater runoff. However, long-term biological data that would enable quantification of how these environmental changes affect the intertidal zone and its ecosystem functioning are still lacking. Therefore, the main goal of this study was to evaluate the interannual variability in the structure of an intertidal macrobenthos assemblage in maritime Antarctica (Admiralty Bay, King George Island 62° S). Sampling was carried out in 2011, 2017 and 2019, in early January, at three intertidal levels: low, mid and high. The results clearly show that the intertidal zone remained relatively rich and abundant over the investigated period. The interannual pattern of diversity and species richness was as follows: 2019 > 2017 > 2011. Each studied year was dominated, to varying degrees, by the bivalve Altenaeum charcoti, the gastropods Laevilacunaria antarctica, Laevilitorina caliginosa and Onoba sp., along with the amphipod Paramoera edouardi. The primary driver of interannual variability seems to be random physical disturbances, such as temperature anomalies, ice activity, and wind force. In addition, year-to-year temperature changes may further affect the state and development of intertidal assemblages in a given year. The interannual variation documented here provides a stronger basis for assessing how Antarctic intertidal assemblages may respond to the rapid environmental changes projected for this region.
不断受到干扰的南极潮间带目前正面临着与气候变化有关的额外挑战，例如变暖和融水径流增加。然而，能够量化这些环境变化如何影响潮间带及其生态系统功能的长期生物学数据仍然缺乏。因此，本研究的主要目的是评估南极海洋（Admiralty Bay, King George Island 62°S）潮间带大型底栖动物群落结构的年际变化。在2011年、2017年和2019年1月初，在低、中、高三个潮间带进行了采样。结果清楚地表明，在调查期间，潮间带保持相对丰富和丰富。多样性和物种丰富度的年际格局为：2019 >； 2017 > 2011。在每一年的研究中，双壳类动物Altenaeum charcoti、腹足类动物Laevilacunaria antarctica、Laevilitorina caliginosa和Onoba sp.以及片足类动物paroera edouardi都在不同程度上占主导地位。年际变化的主要驱动因素似乎是随机的物理干扰，如温度异常、冰活动和风力。此外，温度的年际变化可能进一步影响某一年潮间带组合的状态和发展。这里记录的年际变化为评估南极潮间带组合如何响应该地区预计的快速环境变化提供了更有力的基础。
{"title":"Interannual variability in the structure of macrobenthic assemblages in the maritime Antarctic intertidal zone","authors":"Maciej Chelchowski, Piotr Balazy, Piotr Kuklinski","doi":"10.1016/j.csr.2025.105623","DOIUrl":"10.1016/j.csr.2025.105623","url":null,"abstract":"<div><div>The incessantly disturbed Antarctic intertidal zone is currently facing additional challenges associated with climate change, such as warming and increased meltwater runoff. However, long-term biological data that would enable quantification of how these environmental changes affect the intertidal zone and its ecosystem functioning are still lacking. Therefore, the main goal of this study was to evaluate the interannual variability in the structure of an intertidal macrobenthos assemblage in maritime Antarctica (Admiralty Bay, King George Island 62° S). Sampling was carried out in 2011, 2017 and 2019, in early January, at three intertidal levels: low, mid and high. The results clearly show that the intertidal zone remained relatively rich and abundant over the investigated period. The interannual pattern of diversity and species richness was as follows: 2019 > 2017 > 2011. Each studied year was dominated, to varying degrees, by the bivalve <em>Altenaeum charcoti</em>, the gastropods <em>Laevilacunaria antarctica</em>, <em>Laevilitorina caliginosa</em> and <em>Onoba</em> sp., along with the amphipod <em>Paramoera edouardi</em>. The primary driver of interannual variability seems to be random physical disturbances, such as temperature anomalies, ice activity, and wind force. In addition, year-to-year temperature changes may further affect the state and development of intertidal assemblages in a given year. The interannual variation documented here provides a stronger basis for assessing how Antarctic intertidal assemblages may respond to the rapid environmental changes projected for this region.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"297 ","pages":"Article 105623"},"PeriodicalIF":2.2,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145737342","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 : 2025-11-27DOI: 10.1016/j.csr.2025.105620
A. Prajith , Reji Srinivas , M.K. Sreeraj , N. Sreejith , S. Suja , A.V. Sijinkumar
Seamounts and bathymetric highs are prominent features of the southwestern continental margin of India, yet their influence on sediment transport and deposition remains poorly understood. This study investigates the Alleppey Terrace (AT) and adjacent shelf using sediment texture, clay mineralogy, microfossil assemblages, suspended particulate matter fluxes, and regional circulation data to elucidate depositional dynamics and environmental controls. Grain-size analysis reveals a clear contrast between the sand-dominated outer shelf and the clay-rich AT sediments, indicating distinct depositional settings. Clay mineralogy signatures suggest that shelf sediments are primarily riverine in origin, whereas AT sediments derive largely from in situ weathering of local basaltic basement rocks. Microfossil assemblages indicate low surface productivity and minimal sediment reworking over the AT. Seasonal suspended particulate matter flux measurements using a submersible particle-size analyzer (LISST) confirm that land-derived material does not reach the AT regions. Overall, the interplay between limited sediment sources, bathymetric controls, and hydrodynamic processes has created a unique low-energy depositional environment in the AT, contrasting with the more dynamic adjacent shelf. These findings highlight the critical role of bathymetric highs in modulating sediment flux, preserving relic deposits, and influencing paleoenvironmental conditions along the continental margin.
{"title":"The role of bathymetry in shaping sediment deposition: a case study from the Alleppey Terrace and adjacent shelf, southwestern India","authors":"A. Prajith , Reji Srinivas , M.K. Sreeraj , N. Sreejith , S. Suja , A.V. Sijinkumar","doi":"10.1016/j.csr.2025.105620","DOIUrl":"10.1016/j.csr.2025.105620","url":null,"abstract":"<div><div>Seamounts and bathymetric highs are prominent features of the southwestern continental margin of India, yet their influence on sediment transport and deposition remains poorly understood. This study investigates the Alleppey Terrace (AT) and adjacent shelf using sediment texture, clay mineralogy, microfossil assemblages, suspended particulate matter fluxes, and regional circulation data to elucidate depositional dynamics and environmental controls. Grain-size analysis reveals a clear contrast between the sand-dominated outer shelf and the clay-rich AT sediments, indicating distinct depositional settings. Clay mineralogy signatures suggest that shelf sediments are primarily riverine in origin, whereas AT sediments derive largely from in situ weathering of local basaltic basement rocks. Microfossil assemblages indicate low surface productivity and minimal sediment reworking over the AT. Seasonal suspended particulate matter flux measurements using a submersible particle-size analyzer (LISST) confirm that land-derived material does not reach the AT regions. Overall, the interplay between limited sediment sources, bathymetric controls, and hydrodynamic processes has created a unique low-energy depositional environment in the AT, contrasting with the more dynamic adjacent shelf. These findings highlight the critical role of bathymetric highs in modulating sediment flux, preserving relic deposits, and influencing paleoenvironmental conditions along the continental margin.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"297 ","pages":"Article 105620"},"PeriodicalIF":2.2,"publicationDate":"2025-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145685335","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 : 2025-11-25DOI: 10.1016/j.csr.2025.105621
Zhicheng Zhu , Chengqing Ruan , Qinrong Liu , Zhifeng Wang , Jinsheng Qi
Storm surges pose persistent threats to coastal communities, endangering both human lives and infrastructure. While numerical models remain computationally intensive, artificial intelligence (AI) approaches have emerged as efficient alternatives for storm surge forecasting through their superior accuracy and computational efficiency. However, most existing site-specific forecasting models rely on single-point wind and pressure measurements, neglecting the role of regional wind fields that limit the precision of extratropical storm surge forecasts. To address this gap, we developed a novel end-to-end multi-station forecasting framework designed to establish mapping relationships between wind-pressure fields and observational stations. We employ a 3D UNet for spatiotemporal feature extraction from atmospheric fields, followed by Multilayer perceptrons (MLPs) to project these features onto multiple monitoring sites, with integrated Long Short-Term Memory (LSTM) networks for temporal sequence modeling. Validation experiments in the Bohai Sea demonstrate the model's dual capability in multiscale feature abstraction and temporal dynamics capturing, enabling comprehensive storm surge process forecasting. The proposed model achieves significant reductions across multiple error metrics in 48- and 72-h prediction tasks compared to baseline models. This study provides theoretical and practical insights for advancing multi-step storm surge forecasting systems and hybrid models for coastal disaster prevention, particularly for extratropical storm surge.
{"title":"Developing a novel hybrid deep learning model for extratropical storm surge forecasting: A case in the Bohai Sea","authors":"Zhicheng Zhu , Chengqing Ruan , Qinrong Liu , Zhifeng Wang , Jinsheng Qi","doi":"10.1016/j.csr.2025.105621","DOIUrl":"10.1016/j.csr.2025.105621","url":null,"abstract":"<div><div>Storm surges pose persistent threats to coastal communities, endangering both human lives and infrastructure. While numerical models remain computationally intensive, artificial intelligence (AI) approaches have emerged as efficient alternatives for storm surge forecasting through their superior accuracy and computational efficiency. However, most existing site-specific forecasting models rely on single-point wind and pressure measurements, neglecting the role of regional wind fields that limit the precision of extratropical storm surge forecasts. To address this gap, we developed a novel end-to-end multi-station forecasting framework designed to establish mapping relationships between wind-pressure fields and observational stations. We employ a 3D UNet for spatiotemporal feature extraction from atmospheric fields, followed by Multilayer perceptrons (MLPs) to project these features onto multiple monitoring sites, with integrated Long Short-Term Memory (LSTM) networks for temporal sequence modeling. Validation experiments in the Bohai Sea demonstrate the model's dual capability in multiscale feature abstraction and temporal dynamics capturing, enabling comprehensive storm surge process forecasting. The proposed model achieves significant reductions across multiple error metrics in 48- and 72-h prediction tasks compared to baseline models. This study provides theoretical and practical insights for advancing multi-step storm surge forecasting systems and hybrid models for coastal disaster prevention, particularly for extratropical storm surge.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"297 ","pages":"Article 105621"},"PeriodicalIF":2.2,"publicationDate":"2025-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145685334","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 : 2025-11-24DOI: 10.1016/j.csr.2025.105618
Lizhu Tian , Wei Guo , Rafaela Paulo Teixeira , Mingzheng Wen , Yunzhuang Hu , Fu Wang
In time defined by environmental transformation and anthropogenic pressure, understanding the natural geochemical evolution of coastal zones has never been more urgent. The Western Bohai Sea Coast (WBSC) offers a natural archive of significant land-sea evolution, comprising extensive subsurface deposits formed under marine influence during the progradation of the mid-to-late Holocene Yellow River delta. Over time, natural processes such as meteoric water infiltration and groundwater movement have altered the geochemical characteristics of these sediments. This study uses Electrical conductivity (EC) and pH measurements, combined with environmental indicators such as foraminiferal analysis, to explore the desalination of marine-affected subsurface sediments and its impact on pH along the WBSC. Under long-term percolation of meteoric water and groundwater, a spatially continuous low EC zone, or “desalination corridor”, has developed in marine-affected sediments. It narrows seaward from a broad range of active leaching to a restricted depth around the coastal groundwater table, and eventually to in the upper intertidal zone. Along with desalination, marine-affected sediments commonly develop high pH values, with the underlying mechanisms varying depending on distance from the coastline. In the central areas, the alkalinity increase is likely driven by the leaching of the Ca2+ in the sediments, whereas near the coast, the pronounced alkalization around the groundwater table is probably induced by geochemical reactions under high-Na+, low-flux groundwater conditions. These findings highlight a critical environmental dynamic between desalination and pH increase, with implications for soil health, agricultural viability, and ecosystem functioning in coastal regions.
{"title":"Natural desalination of marine-affected subsurface sediments and its impact on pH along the Western Bohai Sea coast","authors":"Lizhu Tian , Wei Guo , Rafaela Paulo Teixeira , Mingzheng Wen , Yunzhuang Hu , Fu Wang","doi":"10.1016/j.csr.2025.105618","DOIUrl":"10.1016/j.csr.2025.105618","url":null,"abstract":"<div><div>In time defined by environmental transformation and anthropogenic pressure, understanding the natural geochemical evolution of coastal zones has never been more urgent. The Western Bohai Sea Coast (WBSC) offers a natural archive of significant land-sea evolution, comprising extensive subsurface deposits formed under marine influence during the progradation of the mid-to-late Holocene Yellow River delta. Over time, natural processes such as meteoric water infiltration and groundwater movement have altered the geochemical characteristics of these sediments. This study uses Electrical conductivity (EC) and pH measurements, combined with environmental indicators such as foraminiferal analysis, to explore the desalination of marine-affected subsurface sediments and its impact on pH along the WBSC. Under long-term percolation of meteoric water and groundwater, a spatially continuous low EC zone, or “desalination corridor”, has developed in marine-affected sediments. It narrows seaward from a broad range of active leaching to a restricted depth around the coastal groundwater table, and eventually to in the upper intertidal zone. Along with desalination, marine-affected sediments commonly develop high pH values, with the underlying mechanisms varying depending on distance from the coastline. In the central areas, the alkalinity increase is likely driven by the leaching of the Ca<sup>2+</sup> in the sediments, whereas near the coast, the pronounced alkalization around the groundwater table is probably induced by geochemical reactions under high-Na<sup>+</sup>, low-flux groundwater conditions. These findings highlight a critical environmental dynamic between desalination and pH increase, with implications for soil health, agricultural viability, and ecosystem functioning in coastal regions.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"297 ","pages":"Article 105618"},"PeriodicalIF":2.2,"publicationDate":"2025-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145618511","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 : 2025-11-24DOI: 10.1016/j.csr.2025.105619
Maria Isabel Aguilar Pérez , Paula Andrea Zapata Ramirez , Aaron Micallef
Cold seeps in the offshore Sinú Basin, Colombian Caribbean, sustain macrofaunal communities in soft sediments, driven by chemosynthetic energy from methane and sulfide. This study investigated macroinfaunal assemblages at 19 stations within a seepage field off the Gulf of Morrosquillo, at depths of 47–166 m. Sampling utilized a Box Corer and ROV assessments, with stations categorized by seepage signal intensity (High, Medium, Low, Blank) and sediment type (Mud, Sandy Mud, Muddy Sand, Sand). A total of 1414 individuals from 115 taxa across four phyla (Annelida, Arthropoda, Mollusca, Echinodermata) were recorded, with Annelida (33 %) and Crustacea (39 %) dominating. Key families, including Ampeliscidae (9.3 %), Syllidae (5.1 %), and Maldanidae (4.5 %), exhibited patchy distributions influenced by sediment grain size and geological features such as mud volcanoes and faults. Ecological indices revealed high richness (Margalef: 5.8), diversity (Shannon-Weaver: 4.1), and uniformity (Pielou: 0.9), indicating a resilient ecosystem. Cluster and ordination analyses identified two main station groups based on mud content (Group 1: 93–99 %; Group 2: 40–55 %), with significant dissimilarities driven by families like Syllidae and Caridea (ANOSIM R = 0.849, p = 0.1 %). BIO-ENV analysis highlighted mud percentage as the primary environmental driver (Rho = 0.747), with salinity, temperature, and depth as secondary factors. Methane concentration showed a moderate influence (Rho = 0.517). These findings underscore the role of sediment texture and local geomorphology in structuring macrofaunal communities, with implications for understanding cold seep biodiversity in the Caribbean.
在哥伦比亚加勒比海地区Sinú离岸盆地的冷渗漏，在甲烷和硫化物的化学合成能量的驱动下，维持着软沉积物中的大型动物群落。本研究调查了Morrosquillo湾外47-166米深度的渗漏场内19个站点的大型动物群落。采样使用了Box cover和ROV评估，并根据渗漏信号强度（高、中、低、空白）和沉积物类型（泥、砂泥、泥沙、砂）对站点进行了分类。共记录到4门（环节动物、节肢动物、软体动物、棘皮动物）115个类群1414只，其中环节动物占33%，甲壳动物占39%。主要科（包括Ampeliscidae（9.3%）、Syllidae（5.1%）和Maldanidae(4.5%)）受沉积物粒度和泥火山、断层等地质特征的影响，呈斑块状分布。生态指数显示丰富度（Margalef: 5.8）、多样性（Shannon-Weaver: 4.1）和均匀度（Pielou: 0.9）较高，表明生态系统具有弹性。聚类和排序分析根据泥含量确定了两个主要的站点组（组1:93 - 99%；组2:40 - 55%），其中Syllidae和Caridea等科的差异显著（ANOSIM R = 0.849, p = 0.1%）。BIO-ENV分析强调，泥浆含量是主要的环境驱动因素（Rho = 0.747），盐度、温度和深度是次要因素。甲烷浓度的影响中等（Rho = 0.517）。这些发现强调了沉积物质地和当地地貌在构建大型动物群落中的作用，对理解加勒比地区的冷渗生物多样性具有重要意义。
{"title":"Macrofauna of soft sediments associated with cold seeps from the offshore Sinú basin, Colombian Caribbean","authors":"Maria Isabel Aguilar Pérez , Paula Andrea Zapata Ramirez , Aaron Micallef","doi":"10.1016/j.csr.2025.105619","DOIUrl":"10.1016/j.csr.2025.105619","url":null,"abstract":"<div><div>Cold seeps in the offshore Sinú Basin, Colombian Caribbean, sustain macrofaunal communities in soft sediments, driven by chemosynthetic energy from methane and sulfide. This study investigated macroinfaunal assemblages at 19 stations within a seepage field off the Gulf of Morrosquillo, at depths of 47–166 m. Sampling utilized a Box Corer and ROV assessments, with stations categorized by seepage signal intensity (High, Medium, Low, Blank) and sediment type (Mud, Sandy Mud, Muddy Sand, Sand). A total of 1414 individuals from 115 taxa across four phyla (Annelida, Arthropoda, Mollusca, Echinodermata) were recorded, with Annelida (33 %) and Crustacea (39 %) dominating. Key families, including Ampeliscidae (9.3 %), Syllidae (5.1 %), and Maldanidae (4.5 %), exhibited patchy distributions influenced by sediment grain size and geological features such as mud volcanoes and faults. Ecological indices revealed high richness (Margalef: 5.8), diversity (Shannon-Weaver: 4.1), and uniformity (Pielou: 0.9), indicating a resilient ecosystem. Cluster and ordination analyses identified two main station groups based on mud content (Group 1: 93–99 %; Group 2: 40–55 %), with significant dissimilarities driven by families like Syllidae and Caridea (ANOSIM R = 0.849, p = 0.1 %). BIO-ENV analysis highlighted mud percentage as the primary environmental driver (Rho = 0.747), with salinity, temperature, and depth as secondary factors. Methane concentration showed a moderate influence (Rho = 0.517). These findings underscore the role of sediment texture and local geomorphology in structuring macrofaunal communities, with implications for understanding cold seep biodiversity in the Caribbean.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"297 ","pages":"Article 105619"},"PeriodicalIF":2.2,"publicationDate":"2025-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145790319","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.csr.2025.105615
Fernando A. Oreiro , Mónica M.E. Fiore , María F. de Azkue , María F. Canero , Luciano Banegas , Mariana C. Mora
This study presents a comprehensive analysis of relative mean sea level (MSL) variations along the Argentine coast, based on tide gauge data from 12 stations. Hourly water level records—collected by the Argentine Naval Hydrographic Service and other institutions—were quality-checked and processed to generate monthly MSL series. These series were corrected for seasonality by subtracting historical monthly means, and annual averages were used to estimate MSL trends. These trends were calculated over the full period of available data at each station, with values ranging from 0.79 mm yr−1 to 3.84 mm yr−1across time spans between 18 and 119 years. Trend analyses conducted over multiple time periods revealed consistent results among geographically close stations when the same periods were compared. For Buenos Aires and Puerto Quequén—both with over a century of observations—a marked acceleration in MSL rise since the 1960s was observed, with post-1965 trends nearly double those of the earlier period. At these stations, trends were estimated over 20-year windows, advanced in one-year increments throughout the entire series, yielding values ranging from −3 mm yr−1 to +9 mm yr−1. This highlights that such short intervals are insufficient for reliable long-term assessments for this stations. In contrast, variability decreased significantly when 40-year and 60-year periods were used. Overall, the findings confirm a consistent upward trend in sea level rise along the Argentine coast and provide critical baseline information for coastal risk management and climate change adaptation strategies.
本研究基于12个站点的潮汐计数据，对阿根廷海岸的相对平均海平面（MSL）变化进行了全面分析。每小时的水位记录——由阿根廷海军水文测绘局和其他机构收集——经过质量检查和处理，生成每月的MSL系列。这些序列通过减去历史月平均值来校正季节性，并使用年平均值来估计MSL趋势。这些趋势是在每个站点的整个可用数据期内计算的，在18至119年的时间跨度内，其值从0.79 mm yr - 1到3.84 mm yr - 1不等。在多个时期进行的趋势分析表明，在同一时期进行比较时，地理位置接近的站点的结果是一致的。对于布宜诺斯艾利斯和Puerto quequ - - -两者都有超过一个世纪的观测- - -自20世纪60年代以来，观测到MSL的显著加速上升，1965年后的趋势几乎是早期的两倍。在这些站点，估计了20年窗口的趋势，在整个系列中以一年为增量推进，得到的值从−3毫米/年−1到+9毫米/年−1。这突出表明，如此短的时间间隔不足以对这些台站进行可靠的长期评估。相比之下，当使用40年和60年的周期时，变异性显著降低。总体而言，这些发现证实了阿根廷沿海海平面上升的持续上升趋势，并为沿海风险管理和气候变化适应战略提供了关键的基线信息。
{"title":"Relative sea level trends along the Argentine coast: A multi-decadal analysis from tide gauge records","authors":"Fernando A. Oreiro , Mónica M.E. Fiore , María F. de Azkue , María F. Canero , Luciano Banegas , Mariana C. Mora","doi":"10.1016/j.csr.2025.105615","DOIUrl":"10.1016/j.csr.2025.105615","url":null,"abstract":"<div><div>This study presents a comprehensive analysis of relative mean sea level (MSL) variations along the Argentine coast, based on tide gauge data from 12 stations. Hourly water level records—collected by the Argentine Naval Hydrographic Service and other institutions—were quality-checked and processed to generate monthly MSL series. These series were corrected for seasonality by subtracting historical monthly means, and annual averages were used to estimate MSL trends. These trends were calculated over the full period of available data at each station, with values ranging from 0.79 mm yr<sup>−1</sup> to 3.84 mm yr<sup>−1</sup>across time spans between 18 and 119 years. Trend analyses conducted over multiple time periods revealed consistent results among geographically close stations when the same periods were compared. For Buenos Aires and Puerto Quequén—both with over a century of observations—a marked acceleration in MSL rise since the 1960s was observed, with post-1965 trends nearly double those of the earlier period. At these stations, trends were estimated over 20-year windows, advanced in one-year increments throughout the entire series, yielding values ranging from −3 mm yr<sup>−1</sup> to +9 mm yr<sup>−1</sup>. This highlights that such short intervals are insufficient for reliable long-term assessments for this stations. In contrast, variability decreased significantly when 40-year and 60-year periods were used. Overall, the findings confirm a consistent upward trend in sea level rise along the Argentine coast and provide critical baseline information for coastal risk management and climate change adaptation strategies.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"297 ","pages":"Article 105615"},"PeriodicalIF":2.2,"publicationDate":"2025-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145555161","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.csr.2025.105607
Aishwarya Purushothaman , Sanu V. Francis , Lathika Cicily Thomas , K.B. Padmakumar
Ciliate-zooplankton associations in marine ecosystems remain largely understudied, despite their ecological significance within the planktonic community. In this study, copepods and ostracods were identified as the primary hosts for various ciliate epibionts, Lecanophryella satyanandani, Paracineta karunakarani, Acineta karamani, Acineta euchaetae, Ephelota coronata and Ephelota crustaceorum, along the coastal and offshore waters of the southeastern Arabian Sea. Detailed observations on the morphology, distribution, host specificity, sex preference, and attachment sites of the ciliate epibionts enhance existing knowledge. Female zooplankton were more frequently colonised than males, and epibiotic associations were more pronounced in offshore regions, except for ostracod-ciliate interactions, which were more prevalent in coastal waters. Temperature, salinity, and nutrients were found to be the key physicochemical factors influencing the epibiotic associations. The relationship between ciliate colonisation and chlorophyll a concentrations revealed that oligotrophic offshore waters of the southeastern Arabian Sea supported higher incidences of epibiotic associations. The study provides the first comprehensive dataset on the zooplankton-ciliate association across the entire southeastern Arabian Sea, contributing valuable insights into animal interactions in marine systems.
{"title":"Prevalence of epibiotic ciliates on crustacean zooplankton in the Southeastern Arabian Sea","authors":"Aishwarya Purushothaman , Sanu V. Francis , Lathika Cicily Thomas , K.B. Padmakumar","doi":"10.1016/j.csr.2025.105607","DOIUrl":"10.1016/j.csr.2025.105607","url":null,"abstract":"<div><div>Ciliate-zooplankton associations in marine ecosystems remain largely understudied, despite their ecological significance within the planktonic community. In this study, copepods and ostracods were identified as the primary hosts for various ciliate epibionts, <em>Lecanophryella satyanandani, Paracineta karunakarani, Acineta karamani, Acineta euchaetae, Ephelota coronata</em> and <em>Ephelota crustaceorum,</em> along the coastal and offshore waters of the southeastern Arabian Sea. Detailed observations on the morphology, distribution, host specificity, sex preference, and attachment sites of the ciliate epibionts enhance existing knowledge. Female zooplankton were more frequently colonised than males, and epibiotic associations were more pronounced in offshore regions, except for ostracod-ciliate interactions, which were more prevalent in coastal waters. Temperature, salinity, and nutrients were found to be the key physicochemical factors influencing the epibiotic associations. The relationship between ciliate colonisation and chlorophyll <em>a</em> concentrations revealed that oligotrophic offshore waters of the southeastern Arabian Sea supported higher incidences of epibiotic associations. The study provides the first comprehensive dataset on the zooplankton-ciliate association across the entire southeastern Arabian Sea, contributing valuable insights into animal interactions in marine systems.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"297 ","pages":"Article 105607"},"PeriodicalIF":2.2,"publicationDate":"2025-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145618510","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}
Interactions between oceanic mesoscale currents and inertia-gravity waves (IGWs) are thought to facilitate the energy transition toward submesoscale regimes. Such mesoscale–submesoscale transition processes involve unbalanced motions, such as the IGWs, making it difficult to distinguish between them in observational data. Using across-shelf scale-selective filters, we separated the IGWs from a quasi-geostrophic (QG) current, the Coastal Oyashio (CO), based on a CTD-measured hydrographic section with ∼2-km resolution across the Pacific shelf off southeast Hokkaido, Japan, and clarified the mesoscale–submesoscale transition processes in this IGW–QG coupled system. To determine the optimum smoothing scale , we formulated indices based on non-dimensional numbers such as the Rossby number and the Richardson number , calculated from the CTD-derived along-shelf baroclinic velocity. Applying a low-pass filter with to the in-situ density section, where and were of magnitude O(1), resulted in a smoothed section where both and were reduced to ∼O(0.1), with . The smoothed isopycnals were sloped over the Rossby radius of deformation , consistent with the geostrophic adjustment theory. More quantitatively, the diagnosis yielded an optimal smoothing scale of = 6 km. The IGWs propagating along the subsurface pycnocline, characterized by 1 km (i.e., a wavelength around 6 km, ), were successfully separated from the baroclinic jet structure of the CO, which had 10 km. As a result, our observations revealed a hybrid of symmetric and gravitational instability associated with IGW-breaking near the core of the CO baroclinic jet.
{"title":"Across-shelf scale-selective separation of a quasi-geostrophic current and internal gravity waves off southeastern Hokkaido, Japan","authors":"Tatsuro Karaki , Yukiko Taniuchi, Hiromi Kasai, Hiroshi Kuroda","doi":"10.1016/j.csr.2025.105606","DOIUrl":"10.1016/j.csr.2025.105606","url":null,"abstract":"<div><div>Interactions between oceanic mesoscale currents and inertia-gravity waves (IGWs) are thought to facilitate the energy transition toward submesoscale regimes. Such mesoscale–submesoscale transition processes involve unbalanced motions, such as the IGWs, making it difficult to distinguish between them in observational data. Using across-shelf scale-selective filters, we separated the IGWs from a quasi-geostrophic (QG) current, the Coastal Oyashio (CO), based on a CTD-measured hydrographic section with ∼2-km resolution across the Pacific shelf off southeast Hokkaido, Japan, and clarified the mesoscale–submesoscale transition processes in this IGW–QG coupled system. To determine the optimum smoothing scale <span><math><mrow><msub><mrow><mo>Δ</mo><mi>Y</mi></mrow><mi>o</mi></msub></mrow></math></span>, we formulated indices based on non-dimensional numbers such as the Rossby number <span><math><mrow><msub><mi>R</mi><mi>o</mi></msub></mrow></math></span> and the Richardson number <span><math><mrow><msub><mi>R</mi><mi>i</mi></msub></mrow></math></span>, calculated from the CTD-derived along-shelf baroclinic velocity. Applying a low-pass filter with <span><math><mrow><msub><mrow><mo>Δ</mo><mi>Y</mi></mrow><mi>o</mi></msub></mrow></math></span> to the in-situ density section, where <span><math><mrow><msub><mi>R</mi><mi>o</mi></msub></mrow></math></span> and <span><math><mrow><msubsup><mrow><mspace></mspace><mi>R</mi></mrow><mi>i</mi><mrow><mo>−</mo><mn>1</mn></mrow></msubsup></mrow></math></span> were of magnitude <em>O</em>(1), resulted in a smoothed section where both <span><math><mrow><msub><mi>R</mi><mi>o</mi></msub></mrow></math></span> and <span><math><mrow><msubsup><mi>R</mi><mi>i</mi><mrow><mo>−</mo><mn>1</mn></mrow></msubsup></mrow></math></span> were reduced to ∼<em>O</em>(0.1), with <span><math><mrow><msub><mi>R</mi><mi>o</mi></msub><mo>≈</mo><msubsup><mi>R</mi><mi>i</mi><mrow><mo>−</mo><mn>1</mn></mrow></msubsup></mrow></math></span>. The smoothed isopycnals were sloped over the Rossby radius of deformation <span><math><mrow><msub><mi>L</mi><mi>d</mi></msub></mrow></math></span>, consistent with the geostrophic adjustment theory. More quantitatively, the diagnosis yielded an optimal smoothing scale of <span><math><mrow><msub><mrow><mo>Δ</mo><mi>Y</mi></mrow><mi>o</mi></msub></mrow></math></span> = 6 km. The IGWs propagating along the subsurface pycnocline, characterized by <span><math><mrow><msub><mi>L</mi><mi>d</mi></msub><mo>≈</mo></mrow></math></span> 1 km (i.e., a wavelength around 6 km, <span><math><mrow><mn>2</mn><mi>π</mi><msub><mi>L</mi><mi>d</mi></msub></mrow></math></span>), were successfully separated from the baroclinic jet structure of the CO, which had <span><math><mrow><msub><mi>L</mi><mi>d</mi></msub><mo>≈</mo></mrow></math></span> 10 km. As a result, our observations revealed a hybrid of symmetric and gravitational instability associated with IGW-breaking near the core of the CO baroclinic jet.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"296 ","pages":"Article 105606"},"PeriodicalIF":2.2,"publicationDate":"2025-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145520169","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.csr.2025.105605
J. Kämpf
A three-dimensional hydrodynamic model is applied to study the flushing of two large neighboring inverse estuaries, Spencer Gulf and Gulf St. Vincent, South Australia, with and without tides. A density-driven overturning circulation, peaking in austral late winter and spring, controls the flushing of both gulfs. Tidal effects significantly affect the flushing of both estuaries with seawater from the ambient continental shelf. Tidally enhanced friction slows the mean flow and significantly reduces the flushing of the Upper Spencer Gulf by ∼9 months. Here, the tidal effect indirectly creates a more hypersaline, dynamically sheltered environment that ecologically supports the world's only mass aggregation of the Giant Australian Cuttlefish (Sepia apama). On the other hand, tidal mixing prevents the accumulation of dense water in a seafloor depression in the lower Gulf St. Vincent which increases the flushing of this region by ∼6 months. Findings of this study reveal the significance and opposite roles that tides play in the unique marine environment of South Australian gulfs.
{"title":"How tides significantly alter the flushing of two large neighboring inverse estuaries","authors":"J. Kämpf","doi":"10.1016/j.csr.2025.105605","DOIUrl":"10.1016/j.csr.2025.105605","url":null,"abstract":"<div><div>A three-dimensional hydrodynamic model is applied to study the flushing of two large neighboring inverse estuaries, Spencer Gulf and Gulf St. Vincent, South Australia, with and without tides. A density-driven overturning circulation, peaking in austral late winter and spring, controls the flushing of both gulfs. Tidal effects significantly affect the flushing of both estuaries with seawater from the ambient continental shelf. Tidally enhanced friction slows the mean flow and significantly reduces the flushing of the Upper Spencer Gulf by ∼9 months. Here, the tidal effect indirectly creates a more hypersaline, dynamically sheltered environment that ecologically supports the world's only mass aggregation of the Giant Australian Cuttlefish (<em>Sepia apama</em>). On the other hand, tidal mixing prevents the accumulation of dense water in a seafloor depression in the lower Gulf St. Vincent which increases the flushing of this region by ∼6 months. Findings of this study reveal the significance and opposite roles that tides play in the unique marine environment of South Australian gulfs.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"296 ","pages":"Article 105605"},"PeriodicalIF":2.2,"publicationDate":"2025-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145520171","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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