Pub Date : 2025-10-01Epub Date: 2025-07-17DOI: 10.1016/j.csr.2025.105529
Renato D. Ghisolfi , Natiely Monteiro , Guilherme N. Mill , Ruy K.P. Kikuchi , Rodrigo L. Moura
Accurate estimates of ocean temperatures are needed to assess the consequences and improve predictions of thermal stress over coral reefs, which are declining globally due to mass coral bleaching and mortality episodes caused by maritime heatwaves. Here, we contrasted satellite-derived sea surface temperatures (SSTs) recovered from NOAA Coral Reef Watch (CoralTemp) with in situ temperatures measured between 2012 and 2018 in nine locations within the Southwestern Atlantic's largest coral reefs (Abrolhos Bank, Brazil), at different depths. Our results revealed a strong correlation (over 0.95) between the two datasets for measurements carried out to 10 m depths or within the mixed layer. In the dry period (April to September), when the water column is homogenous and the net heat flux through the air-sea interface is negative, temperature data collected below the mixing layer or at the bottom were consistent with CoralTemp. However, in situ measurements were much lower (up to 4 °C at some sites) during the rainy period (from October to March) due to cold water occurrence in the bottom half of the water column. During the Third Global Bleaching Event (2016–2017) bleaching levels in shallow reefs were more intense than the thermal stress estimated by CoralTemp. Still, they were lower in the deeper reefs that remained with lower in situ temperatures throughout the summer and autumn. While we confirm that CoralTemp data provide a reliable source of sea surface temperatures (SSTs), caution is advised when inferring thermal stress at greater depths, particularly in mesophotic sites deeper than 20 m.
{"title":"Spatial-temporal reliability of satellite-derived temperature and thermal stress in the abrolhos bank, Brazil","authors":"Renato D. Ghisolfi , Natiely Monteiro , Guilherme N. Mill , Ruy K.P. Kikuchi , Rodrigo L. Moura","doi":"10.1016/j.csr.2025.105529","DOIUrl":"10.1016/j.csr.2025.105529","url":null,"abstract":"<div><div>Accurate estimates of ocean temperatures are needed to assess the consequences and improve predictions of thermal stress over coral reefs, which are declining globally due to mass coral bleaching and mortality episodes caused by maritime heatwaves. Here, we contrasted satellite-derived sea surface temperatures (SSTs) recovered from NOAA Coral Reef Watch (CoralTemp) with in situ temperatures measured between 2012 and 2018 in nine locations within the Southwestern Atlantic's largest coral reefs (Abrolhos Bank, Brazil), at different depths. Our results revealed a strong correlation (over 0.95) between the two datasets for measurements carried out to 10 m depths or within the mixed layer. In the dry period (April to September), when the water column is homogenous and the net heat flux through the air-sea interface is negative, temperature data collected below the mixing layer or at the bottom were consistent with CoralTemp. However, in situ measurements were much lower (up to 4 °C at some sites) during the rainy period (from October to March) due to cold water occurrence in the bottom half of the water column. During the Third Global Bleaching Event (2016–2017) bleaching levels in shallow reefs were more intense than the thermal stress estimated by CoralTemp. Still, they were lower in the deeper reefs that remained with lower in situ temperatures throughout the summer and autumn. While we confirm that CoralTemp data provide a reliable source of sea surface temperatures (SSTs), caution is advised when inferring thermal stress at greater depths, particularly in mesophotic sites deeper than 20 m.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"293 ","pages":"Article 105529"},"PeriodicalIF":2.1,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144695470","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}
Coastal upwelling plays a critical role in the marine biogeochemical environment by bringing nutrient-rich deep water to the surface, thereby fostering the development of high-biomass fishing grounds, such as the Zhoushan upwelling system in China. High-resolution Level-2 satellite-derived Sea Surface Temperature (SST) data captured notable upwelling events in the Zhoushan Archipelago, even under persistent northerly upwelling-unfavorable winds lasting over one week. Further analysis revealed that these upwelling-unfavorable winds not only generated onshore Ekman transport but also induced a negative wind stress curl, both of which acted to suppress upwelling. However, the weighted cumulative topographic position index demonstrated a quasi-steady upwelling intensity despite the unfavorable wind forcing. Under upwelling-favorable winds, a northward coastal current dominates the Zhoushan Archipelago offshore region, whereas a southward coastal current prevails under upwelling-unfavorable winds. The Zhoushan Archipelago features two prominent meridional topographic slopes formed by its two island chains. When northward or southward coastal current interacts with these slopes, upslope motion occurs on the stream-facing side, facilitating the upwelling of deeper cold water. Additionally, strong tidal current within the shallow waters surrounding the islands generates intense tidal mixing, further enhancing the upward transport of colder water to the surface. The locally enhanced current-topography interaction, tidal mixing, and leeward upwelling nearby the islands collectively trigger multiple cold upwelling cores around the islands, leading to a heterogeneous spatial distribution of upwelling around Zhoushan Archipelago.
{"title":"The vital role of current-topography interaction and tidal mixing in the upwelling around Zhoushan Archipelago","authors":"Jianshe Mu, Juncheng Xie, Peng Bai, Bo Li, Jingling Yang, Ying Gao","doi":"10.1016/j.csr.2025.105514","DOIUrl":"10.1016/j.csr.2025.105514","url":null,"abstract":"<div><div>Coastal upwelling plays a critical role in the marine biogeochemical environment by bringing nutrient-rich deep water to the surface, thereby fostering the development of high-biomass fishing grounds, such as the Zhoushan upwelling system in China. High-resolution Level-2 satellite-derived Sea Surface Temperature (SST) data captured notable upwelling events in the Zhoushan Archipelago, even under persistent northerly upwelling-unfavorable winds lasting over one week. Further analysis revealed that these upwelling-unfavorable winds not only generated onshore Ekman transport but also induced a negative wind stress curl, both of which acted to suppress upwelling. However, the weighted cumulative topographic position index demonstrated a quasi-steady upwelling intensity despite the unfavorable wind forcing. Under upwelling-favorable winds, a northward coastal current dominates the Zhoushan Archipelago offshore region, whereas a southward coastal current prevails under upwelling-unfavorable winds. The Zhoushan Archipelago features two prominent meridional topographic slopes formed by its two island chains. When northward or southward coastal current interacts with these slopes, upslope motion occurs on the stream-facing side, facilitating the upwelling of deeper cold water. Additionally, strong tidal current within the shallow waters surrounding the islands generates intense tidal mixing, further enhancing the upward transport of colder water to the surface. The locally enhanced current-topography interaction, tidal mixing, and leeward upwelling nearby the islands collectively trigger multiple cold upwelling cores around the islands, leading to a heterogeneous spatial distribution of upwelling around Zhoushan Archipelago.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"293 ","pages":"Article 105514"},"PeriodicalIF":2.1,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144570749","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 : 2025-10-01Epub Date: 2025-07-11DOI: 10.1016/j.csr.2025.105524
Yu Yao , Yuting Song , Long Chen , Changshen Li
Most existing studies reports that many low-lying reef atoll islands are vulnerable to the sea level rise and increased storminess in the context of global climate change. The positive adjustment of these reef islands to such extreme oceanographic conditions still needs to be further verified. In this study, the open-source XBeach numerical model using its phase-resolving nonhydrostatic module (XB-NH) combined with its morphodynamic module is adopted to investigate the morphodynamic response of reef islands under spectral waves. The model is firstly validated by two published datasets with and without the presence of sandy island located on the reef flat. The model is then applied to examine the effects of a series of incident wave forcing conditions (significant wave height, peak wave period, reef flat water depth) and island initial morphological features (island height, island top width, island beach slope, island location) on the morphodynamic evolution of reef island. Model applications show that two main morphodynamic responses: the elevated reef island crest and the lagoonward migration of the whole island are identified with larger waves and increased water level. One or two of such morphodynamic self-adjustment can be also found for smaller island with steeper beach slope located more closer to the reef edge. These insights highlight the necessity to consider the island morphological features in the coastal management of low-lying reef atoll nations to better resolve their future stability and persistence.
{"title":"A numerical study of the morphodynamic response of reef islands under spectral waves","authors":"Yu Yao , Yuting Song , Long Chen , Changshen Li","doi":"10.1016/j.csr.2025.105524","DOIUrl":"10.1016/j.csr.2025.105524","url":null,"abstract":"<div><div>Most existing studies reports that many low-lying reef atoll islands are vulnerable to the sea level rise and increased storminess in the context of global climate change. The positive adjustment of these reef islands to such extreme oceanographic conditions still needs to be further verified. In this study, the open-source XBeach numerical model using its phase-resolving nonhydrostatic module (XB-NH) combined with its morphodynamic module is adopted to investigate the morphodynamic response of reef islands under spectral waves. The model is firstly validated by two published datasets with and without the presence of sandy island located on the reef flat. The model is then applied to examine the effects of a series of incident wave forcing conditions (significant wave height, peak wave period, reef flat water depth) and island initial morphological features (island height, island top width, island beach slope, island location) on the morphodynamic evolution of reef island. Model applications show that two main morphodynamic responses: the elevated reef island crest and the lagoonward migration of the whole island are identified with larger waves and increased water level. One or two of such morphodynamic self-adjustment can be also found for smaller island with steeper beach slope located more closer to the reef edge. These insights highlight the necessity to consider the island morphological features in the coastal management of low-lying reef atoll nations to better resolve their future stability and persistence.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"293 ","pages":"Article 105524"},"PeriodicalIF":2.1,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144614653","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 : 2025-10-01Epub Date: 2025-07-28DOI: 10.1016/j.csr.2025.105534
Ziying Zhou , Zhi Yang , Bin Wang , Haiyan Jin , Lihua Ran , Zhibing Jiang , Qianna Chen , Feng Zhou , Hao Zheng , Jianfang Chen
The complex hydrodynamic conditions in the Yangtze River Estuary play a pivotal role in shaping the distribution, transport, and transformation of nutrients, thereby influencing phytoplankton growth and ecosystem stability in the region. This study, based on hydrographic, biological, and chemical data collected during a mid-August 2023 cruise survey in the Yangtze River Estuary and the adjacent East China Sea, integrates nitrate nitrogen (δ15NNO3) and oxygen isotope (δ18ONO3) tracing techniques to investigate the synergistic effects of physical-biogeochemical processes during water mass convergence. The findings reveal that high concentrations of terrestrial nitrate, transported by the Changjiang Diluted Water (CDW), serve as the primary inorganic nitrogen source, driving rapid phytoplankton growth. Meanwhile, the Yellow Sea Coastal Current (YSCC) and Taiwan Warm Current (TWC) regulate nutrient transport and redistribution through mixing and convergence processes. The high phosphate input from the TWC optimizes the regional nutrient structure, alleviating phosphorus limitation caused by excessive nitrogen input from the CDW. However, the intrusion of low-oxygen YSCC waters may worsen bottom-water hypoxia. The frontal systems and water column stratification, induced by the convergence of CDW, YSCC, and TWC, control the spatial distribution of nitrogen and phosphorus nutrients, shape phytoplankton distribution patterns, and foster the formation of localized high-productivity zones. The synergistic effects of physical and biogeochemical processes, driven by water mass interactions, can significantly reduce bottom-water dissolved oxygen concentrations, thereby increasing the risk of localized hypoxia and threatening regional ecosystem stability.
{"title":"Nitrogen cycling and ecological impacts mediated by water mass interactions in the Yangtze river estuary and the adjacent east China Sea: insights from nitrogen and oxygen isotopes","authors":"Ziying Zhou , Zhi Yang , Bin Wang , Haiyan Jin , Lihua Ran , Zhibing Jiang , Qianna Chen , Feng Zhou , Hao Zheng , Jianfang Chen","doi":"10.1016/j.csr.2025.105534","DOIUrl":"10.1016/j.csr.2025.105534","url":null,"abstract":"<div><div>The complex hydrodynamic conditions in the Yangtze River Estuary play a pivotal role in shaping the distribution, transport, and transformation of nutrients, thereby influencing phytoplankton growth and ecosystem stability in the region. This study, based on hydrographic, biological, and chemical data collected during a mid-August 2023 cruise survey in the Yangtze River Estuary and the adjacent East China Sea, integrates nitrate nitrogen (δ<sup>15</sup>N<sub>NO3</sub>) and oxygen isotope (δ<sup>18</sup>O<sub>NO3</sub>) tracing techniques to investigate the synergistic effects of physical-biogeochemical processes during water mass convergence. The findings reveal that high concentrations of terrestrial nitrate, transported by the Changjiang Diluted Water (CDW), serve as the primary inorganic nitrogen source, driving rapid phytoplankton growth. Meanwhile, the Yellow Sea Coastal Current (YSCC) and Taiwan Warm Current (TWC) regulate nutrient transport and redistribution through mixing and convergence processes. The high phosphate input from the TWC optimizes the regional nutrient structure, alleviating phosphorus limitation caused by excessive nitrogen input from the CDW. However, the intrusion of low-oxygen YSCC waters may worsen bottom-water hypoxia. The frontal systems and water column stratification, induced by the convergence of CDW, YSCC, and TWC, control the spatial distribution of nitrogen and phosphorus nutrients, shape phytoplankton distribution patterns, and foster the formation of localized high-productivity zones. The synergistic effects of physical and biogeochemical processes, driven by water mass interactions, can significantly reduce bottom-water dissolved oxygen concentrations, thereby increasing the risk of localized hypoxia and threatening regional ecosystem stability.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"293 ","pages":"Article 105534"},"PeriodicalIF":2.2,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144757596","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 : 2025-10-01Epub Date: 2025-07-07DOI: 10.1016/j.csr.2025.105511
Hongliang Yu , Zheen Zhang , Lan Li , Chunxin Yuan , Zhen Gao , Xueen Chen
The high-resolution Oceanic Regional Circulation and Tide Model (ORCTM) with a compatible Ensemble Adjustment Kalman Filter (EAKF) assimilation module is implemented to investigate the general evolution and long-term trend of the Bohai Sea cold water mass (BHSCWM). Through comparison with multiple observational data, it can be proved that the reliability of model results is significantly improved after the data assimilation. The assimilated results from 2011 to 2020 show that the BHSCWM occurs from May to August, and its formation is closely related to the seasonal thermocline at a depth of about 10 m. There is a vertically uniform high-temperature water column in the central bank, which divides the BHSCWM into the south part (SBHSCWM) and the north part (NBHSCWM). It is noteworthy that there is a remarkable warming trend in the BHSCWM core, the warming rate reaches 0.24 °C/yr and 0.15 °C/yr for the SBHSCWM and the NBHSCWM, respectively. Meanwhile, whether in terms of cold water mass affected area or volume, a significant decreasing trend for both the SBHSCWM and the NBHSCWM is revealed by our assimilated results, suggesting that the Bohai Sea may be dramatically impacted in the context of global warming.
{"title":"Weakening trend of Bohai Sea cold water mass revealed by a ten-year regional ocean simulation with data assimilation","authors":"Hongliang Yu , Zheen Zhang , Lan Li , Chunxin Yuan , Zhen Gao , Xueen Chen","doi":"10.1016/j.csr.2025.105511","DOIUrl":"10.1016/j.csr.2025.105511","url":null,"abstract":"<div><div>The high-resolution Oceanic Regional Circulation and Tide Model (ORCTM) with a compatible Ensemble Adjustment Kalman Filter (EAKF) assimilation module is implemented to investigate the general evolution and long-term trend of the Bohai Sea cold water mass (BHSCWM). Through comparison with multiple observational data, it can be proved that the reliability of model results is significantly improved after the data assimilation. The assimilated results from 2011 to 2020 show that the BHSCWM occurs from May to August, and its formation is closely related to the seasonal thermocline at a depth of about 10 m. There is a vertically uniform high-temperature water column in the central bank, which divides the BHSCWM into the south part (SBHSCWM) and the north part (NBHSCWM). It is noteworthy that there is a remarkable warming trend in the BHSCWM core, the warming rate reaches 0.24 °C/yr and 0.15 °C/yr for the SBHSCWM and the NBHSCWM, respectively. Meanwhile, whether in terms of cold water mass affected area or volume, a significant decreasing trend for both the SBHSCWM and the NBHSCWM is revealed by our assimilated results, suggesting that the Bohai Sea may be dramatically impacted in the context of global warming.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"293 ","pages":"Article 105511"},"PeriodicalIF":2.1,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144579706","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}
Recreational activities are important source of disturbance on sandy beaches and have a negative effect on meiofauna communities as they alter species abundance, diversity, and/or distribution. Here, we report for the first time the effects of recreational activities on the distribution patterns of meiofauna communities and Nematoda assemblages of Amazonian sandy beaches. Sampling was performed during four consecutive months with different beach use intensity in 2017 (June – before vacation, July – vacation month, August and September - after vacation months) on two contrasting beaches regarding disturbance (Urban: Atalaia; and Protected: Corvinas). Physical sediment variables remained constant over time in both beaches, whereas differences were found in sediment compaction over the periods. Sediment compaction was considered the most important factor for the differences observed in meiofauna community and Nematoda assemblage structures in the beaches, and it was related to intensity of recreational activities. Overall, variations in density and changes in richness between periods and sampling stations were observed in Atalaia beach. Before the vacation three faunal zones were distinguished in Atalaia beach (upper intertidal, intermediate intertidal, and low-intertidal), whereas in the vacation period only two faunal zones were distinguished (upper-intertidal and intermediate-low intertidal). On the other hand, Corvinas beach remained the same throughout the study. Thus, the initial hypothesis that recreational activities trigger changes in the structure and composition of meiofauna and Nematoda, reducing richness and abundance of the community, was confirmed. Furthermore, the vulnerability of some taxa studied here, particularly Copepoda and Tardigrada, and the Nematoda genera Chromadorita and Daptonema indicates that they might be potential indicators of recreational activities.
{"title":"Human trampling and vehicle traffic affect meiofauna and Nematoda distribution patterns in Amazonian macrotidal sandy beaches","authors":"Thuareag Monteiro Trindade dos Santos , Marcelo Petracco , Virág Venekey","doi":"10.1016/j.csr.2025.105533","DOIUrl":"10.1016/j.csr.2025.105533","url":null,"abstract":"<div><div>Recreational activities are important source of disturbance on sandy beaches and have a negative effect on meiofauna communities as they alter species abundance, diversity, and/or distribution. Here, we report for the first time the effects of recreational activities on the distribution patterns of meiofauna communities and Nematoda assemblages of Amazonian sandy beaches. Sampling was performed during four consecutive months with different beach use intensity in 2017 (June – before vacation, July – vacation month, August and September - after vacation months) on two contrasting beaches regarding disturbance (Urban: Atalaia; and Protected: Corvinas). Physical sediment variables remained constant over time in both beaches, whereas differences were found in sediment compaction over the periods. Sediment compaction was considered the most important factor for the differences observed in meiofauna community and Nematoda assemblage structures in the beaches, and it was related to intensity of recreational activities. Overall, variations in density and changes in richness between periods and sampling stations were observed in Atalaia beach. Before the vacation three faunal zones were distinguished in Atalaia beach (upper intertidal, intermediate intertidal, and low-intertidal), whereas in the vacation period only two faunal zones were distinguished (upper-intertidal and intermediate-low intertidal). On the other hand, Corvinas beach remained the same throughout the study. Thus, the initial hypothesis that recreational activities trigger changes in the structure and composition of meiofauna and Nematoda, reducing richness and abundance of the community, was confirmed. Furthermore, the vulnerability of some taxa studied here, particularly Copepoda and Tardigrada, and the Nematoda genera <em>Chromadorita</em> and <em>Daptonema</em> indicates that they might be potential indicators of recreational activities.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"293 ","pages":"Article 105533"},"PeriodicalIF":2.2,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144721025","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 : 2025-10-01Epub Date: 2025-07-14DOI: 10.1016/j.csr.2025.105527
Songhua Shang , Jiehao Li , Hailong Tian , Tianfu Xu , Wei Wang , Wei Yuan , Qinghe Niu , Yongxiang Zheng , Jing Li
Marine sediments serve as reservoirs for methane, a potent greenhouse gas and a promising clean energy source. As methane migrates from deep to shallow layers, it undergoes oxidation-reduction reactions with various electron acceptors, such as sulfate, nitrate, and oxygen. Aerobic Oxidation of Methane (AeOM) plays a crucial role where dissolved oxygen is available, particularly in marginal seas with shallow water depths. For now, research on AeOM is not in-depth, especially quantitative works. In the Bohai Sea's petroleum and natural gas basins, methane leakage from sediments is common, and conditions for methane oxidation are present. The sediments play a significant role in oxidizing methane, presenting a highly worthwhile subject for research. Therefore, utilizing laboratory data on AeOM, we employed the TOUGH + HR simulation platform to reproduce the AeOM process by an experimental conceptual model. The calibration of microbial kinetic parameters was conducted using sampling and testing data to analyze the characteristics of methane oxidation. Moreover, relationships between kinetic parameters and temperature were established, facilitating parameter estimation. The maximum oxidation rate (qm) shows an exponential relationship with temperature, whereas the microbial decay constant (b) displays a linear relationship. We quantitatively analyzed the characteristics of methane oxidation under different influencing factors, including temperature, pressure, and gas migration velocity. The results revealed that temperature is a key factor in determining methane consumption rates, with higher temperatures leading to significantly faster methane consumption due to its influence on microbial activity. The average oxidation rate was recorded as 0.35 μmol/day at 4 °C. This rate increased to 3.05 μmol/day at 10 °C and further rose to 3.96 μmol/day at 15 °C. Notably, there was a dramatic jump to 15.13 μmol/day when the temperature reached 28 °C. By enhancing methane supply (solubility), pressure can boost methane oxidation consumption. 1 MPa–5 MPa pressure increase raises average methane oxidation rates by 93 %. Methane migration velocity primarily affects the supply efficiency of methane and a 50 μL/min to 150 μL/min velocity increase raises rates by 10.3 %. Compared with the results across various temperatures, pressures, and methane migration velocities, we believe that temperature and pressure have a significant impact on methane oxidation consumption, while methane migration velocity has no significant impact. The temperature and pressure changes should be focused on to evaluate the effect of sediment on methane oxidation interception. This study enhances the understanding of the quantitative assessment of seabed methane leakage and the marine sediment carbon cycle.
{"title":"Evaluating influencing factors of methane interception in Bohai bay basin's aerobic zone based on experiment coupled with modeling","authors":"Songhua Shang , Jiehao Li , Hailong Tian , Tianfu Xu , Wei Wang , Wei Yuan , Qinghe Niu , Yongxiang Zheng , Jing Li","doi":"10.1016/j.csr.2025.105527","DOIUrl":"10.1016/j.csr.2025.105527","url":null,"abstract":"<div><div>Marine sediments serve as reservoirs for methane, a potent greenhouse gas and a promising clean energy source. As methane migrates from deep to shallow layers, it undergoes oxidation-reduction reactions with various electron acceptors, such as sulfate, nitrate, and oxygen. Aerobic Oxidation of Methane (AeOM) plays a crucial role where dissolved oxygen is available, particularly in marginal seas with shallow water depths. For now, research on AeOM is not in-depth, especially quantitative works. In the Bohai Sea's petroleum and natural gas basins, methane leakage from sediments is common, and conditions for methane oxidation are present. The sediments play a significant role in oxidizing methane, presenting a highly worthwhile subject for research. Therefore, utilizing laboratory data on AeOM, we employed the TOUGH + HR simulation platform to reproduce the AeOM process by an experimental conceptual model. The calibration of microbial kinetic parameters was conducted using sampling and testing data to analyze the characteristics of methane oxidation. Moreover, relationships between kinetic parameters and temperature were established, facilitating parameter estimation. The maximum oxidation rate (q<sub>m</sub>) shows an exponential relationship with temperature, whereas the microbial decay constant (b) displays a linear relationship. We quantitatively analyzed the characteristics of methane oxidation under different influencing factors, including temperature, pressure, and gas migration velocity. The results revealed that temperature is a key factor in determining methane consumption rates, with higher temperatures leading to significantly faster methane consumption due to its influence on microbial activity. The average oxidation rate was recorded as 0.35 μmol/day at 4 °C. This rate increased to 3.05 μmol/day at 10 °C and further rose to 3.96 μmol/day at 15 °C. Notably, there was a dramatic jump to 15.13 μmol/day when the temperature reached 28 °C. By enhancing methane supply (solubility), pressure can boost methane oxidation consumption. 1 MPa–5 MPa pressure increase raises average methane oxidation rates by 93 %. Methane migration velocity primarily affects the supply efficiency of methane and a 50 μL/min to 150 μL/min velocity increase raises rates by 10.3 %. Compared with the results across various temperatures, pressures, and methane migration velocities, we believe that temperature and pressure have a significant impact on methane oxidation consumption, while methane migration velocity has no significant impact. The temperature and pressure changes should be focused on to evaluate the effect of sediment on methane oxidation interception. This study enhances the understanding of the quantitative assessment of seabed methane leakage and the marine sediment carbon cycle.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"293 ","pages":"Article 105527"},"PeriodicalIF":2.1,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144633765","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 : 2025-10-01Epub Date: 2025-07-13DOI: 10.1016/j.csr.2025.105513
Pauline H.P. Overes , Bas W. Borsje , Arjen P. Luijendijk , Johan Reyns , Suzanne J.M.H. Hulscher
Sand waves, large scale dynamic bedforms, which are found on sandy, shallow seabeds worldwide, present an immediate risk to offshore structures, raising a pressing need for predicting related bed level dynamics on decadal timescales. Numerical models can help us understand and predict sand wave dynamics, but have shown difficulties with preserving sand wave shapes. Using the process-based Delft3D Flexible Mesh model, we have found that the choice of sediment transport formulation has a significant effect on the stability of sand wave shapes. The widely used Van Rijn (1993) sediment transport formulation predicts relatively high bed load transport rates, thereby raising a need for more dominant slope-induced transport. The simulations revealed that the Van Rijn (2007) formulation, which predicts relatively lower transport rates, and thus allows for lower bed slope-induced transports, is better capable of preserving the steep slopes of sand waves, while limiting sand wave growth. By considering various shape characteristics in our model assessment, more insight is gained about the improvements as well as adverse effects of changes in the parameterization of physical processes. These characteristics show that only with the less dominant bed slope-induced transport the crest levels are stable, while trough levels still lower slowly over time. This indicates that local processes are responsible for limiting the growth of sand waves and the importance of slope-induced transport has been overstated in previous works. With the adapted, non-upscaled set-up, the evolution of sand waves over multiyear timescales is represented well in the model compared to bathymetric field data for two contrasting sand wave field sites.
{"title":"The role of sediment transport processes in shaping offshore sand waves","authors":"Pauline H.P. Overes , Bas W. Borsje , Arjen P. Luijendijk , Johan Reyns , Suzanne J.M.H. Hulscher","doi":"10.1016/j.csr.2025.105513","DOIUrl":"10.1016/j.csr.2025.105513","url":null,"abstract":"<div><div>Sand waves, large scale dynamic bedforms, which are found on sandy, shallow seabeds worldwide, present an immediate risk to offshore structures, raising a pressing need for predicting related bed level dynamics on decadal timescales. Numerical models can help us understand and predict sand wave dynamics, but have shown difficulties with preserving sand wave shapes. Using the process-based Delft3D Flexible Mesh model, we have found that the choice of sediment transport formulation has a significant effect on the stability of sand wave shapes. The widely used Van Rijn (1993) sediment transport formulation predicts relatively high bed load transport rates, thereby raising a need for more dominant slope-induced transport. The simulations revealed that the Van Rijn (2007) formulation, which predicts relatively lower transport rates, and thus allows for lower bed slope-induced transports, is better capable of preserving the steep slopes of sand waves, while limiting sand wave growth. By considering various shape characteristics in our model assessment, more insight is gained about the improvements as well as adverse effects of changes in the parameterization of physical processes. These characteristics show that only with the less dominant bed slope-induced transport the crest levels are stable, while trough levels still lower slowly over time. This indicates that local processes are responsible for limiting the growth of sand waves and the importance of slope-induced transport has been overstated in previous works. With the adapted, non-upscaled set-up, the evolution of sand waves over multiyear timescales is represented well in the model compared to bathymetric field data for two contrasting sand wave field sites.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"293 ","pages":"Article 105513"},"PeriodicalIF":2.1,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144633764","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 : 2025-10-01Epub Date: 2025-07-18DOI: 10.1016/j.csr.2025.105531
Sheng Wang , Xueen Chen , He Jiang , Peng Zheng
The Bohai Sea is a typical continental shelf region, and its water exchange capacity has long been the focus of research. Wave-current interaction (WCI), as an important physical process for the continental shelf hydrodynamics, is worthy of further investigation due to its impact on water exchange in the Bohai Sea. In this study, based on the FVCOM-UnSWAN wave-current coupling model, the water exchange characteristics of the Bohai Sea under the influence of WCI were discussed using the conservative material tracer method. The effects of WCI on water exchange and hydrodynamics were further analyzed under both seasonal variations and extreme weather events. As the only channel connecting the Yellow Sea and the Bohai Sea, changes in the water exchange capacity of the Bohai Strait can reflect the change of the Bohai Sea. Focusing on this region, our results show that WCI modulates water exchange rates: enhancing exchange by approximately 1.3 % in winter, while exhibiting complex behavior in summer, initially suppressing and subsequently enhancing water exchange. During storm surge events, WCI plays a crucial role in modifying hydrodynamic conditions, increasing water elevation by 20 %–35 %, with changes in water velocity up to an order of magnitude larger compared to seasonal scales. During the water exchange process, WCI modifies the current velocity structure by introducing a non-conservative force Fw, among which the white-capping dissipation term plays a dominant role.
{"title":"Effects of wave-current interaction on water exchange in the Bohai Sea","authors":"Sheng Wang , Xueen Chen , He Jiang , Peng Zheng","doi":"10.1016/j.csr.2025.105531","DOIUrl":"10.1016/j.csr.2025.105531","url":null,"abstract":"<div><div>The Bohai Sea is a typical continental shelf region, and its water exchange capacity has long been the focus of research. Wave-current interaction (WCI), as an important physical process for the continental shelf hydrodynamics, is worthy of further investigation due to its impact on water exchange in the Bohai Sea. In this study, based on the FVCOM-UnSWAN wave-current coupling model, the water exchange characteristics of the Bohai Sea under the influence of WCI were discussed using the conservative material tracer method. The effects of WCI on water exchange and hydrodynamics were further analyzed under both seasonal variations and extreme weather events. As the only channel connecting the Yellow Sea and the Bohai Sea, changes in the water exchange capacity of the Bohai Strait can reflect the change of the Bohai Sea. Focusing on this region, our results show that WCI modulates water exchange rates: enhancing exchange by approximately 1.3 % in winter, while exhibiting complex behavior in summer, initially suppressing and subsequently enhancing water exchange. During storm surge events, WCI plays a crucial role in modifying hydrodynamic conditions, increasing water elevation by 20 %–35 %, with changes in water velocity up to an order of magnitude larger compared to seasonal scales. During the water exchange process, WCI modifies the current velocity structure by introducing a non-conservative force <em>F</em><sub><em>w</em></sub>, among which the white-capping dissipation term plays a dominant role.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"293 ","pages":"Article 105531"},"PeriodicalIF":2.1,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144679260","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 : 2025-10-01Epub Date: 2025-07-12DOI: 10.1016/j.csr.2025.105526
Gammon N. Koval , Jenifer E. Dugan , Scott L. Hamilton
Located at the land-sea interface, the highly dynamic sandy beach and surf zone ecosystem is one of the coastal zones used most intensely by humans (e.g., recreation, fishing, tourism). Surf zones are also important as fish habitat; however, the factors structuring fish assemblages in the surf zone are relatively understudied due to challenges associated with sampling this dynamic environment. To investigate temporal influences on surf zone fish communities, we evaluated seasonal trends in the fish assemblage and associations with environmental conditions using baited remote underwater video stations (BRUVS) at four beaches on the Northeast Pacific coast (California, USA) from July 2020 to June 2021. Our study region is characterized by strong seasonality in productivity (due to spring upwelling) and the wave climate (in response to winter storms), making it an ideal location for evaluating seasonal change in surf zone fish. We found that surf zone fish assemblages exhibited marked seasonality and site-to-site variability. Two species of surfperch (Amphistichus argenteus and A. koelzi) and leopard sharks (Triakis semifasciata) were more common in the winter and spring, corresponding with surfperch spawning, while flatfishes were more abundant in the summer. Fish species composition was most affected by distance from shore (as a proxy for surf zone width), visibility, water temperature, percent cover of combined macroalgae and surfgrass, and breaker wave height, with significant effects detected for distance from shore and breaker height. Fish species that exhibited higher abundance in the winter, including A. argenteus, A. koelzi, and T. semifasciata, were associated with larger waves and wider surf zones. Our results highlight the influence of seasonal variation in environmental conditions on fish communities in the dynamic, coastal surf zone ecosystem, with potential management implications for several highly abundant species targeted by recreational fisheries.
{"title":"Seasonal variation and response of surf zone fish assemblages to environmental variables in the Northeast Pacific","authors":"Gammon N. Koval , Jenifer E. Dugan , Scott L. Hamilton","doi":"10.1016/j.csr.2025.105526","DOIUrl":"10.1016/j.csr.2025.105526","url":null,"abstract":"<div><div>Located at the land-sea interface, the highly dynamic sandy beach and surf zone ecosystem is one of the coastal zones used most intensely by humans (e.g., recreation, fishing, tourism). Surf zones are also important as fish habitat; however, the factors structuring fish assemblages in the surf zone are relatively understudied due to challenges associated with sampling this dynamic environment. To investigate temporal influences on surf zone fish communities, we evaluated seasonal trends in the fish assemblage and associations with environmental conditions using baited remote underwater video stations (BRUVS) at four beaches on the Northeast Pacific coast (California, USA) from July 2020 to June 2021. Our study region is characterized by strong seasonality in productivity (due to spring upwelling) and the wave climate (in response to winter storms), making it an ideal location for evaluating seasonal change in surf zone fish. We found that surf zone fish assemblages exhibited marked seasonality and site-to-site variability. Two species of surfperch (<em>Amphistichus argenteus</em> and <em>A. koelzi</em>) and leopard sharks (<em>Triakis semifasciata</em>) were more common in the winter and spring, corresponding with surfperch spawning, while flatfishes were more abundant in the summer. Fish species composition was most affected by distance from shore (as a proxy for surf zone width), visibility, water temperature, percent cover of combined macroalgae and surfgrass, and breaker wave height, with significant effects detected for distance from shore and breaker height. Fish species that exhibited higher abundance in the winter, including <em>A. argenteus</em>, <em>A. koelzi</em>, and <em>T. semifasciata</em>, were associated with larger waves and wider surf zones. Our results highlight the influence of seasonal variation in environmental conditions on fish communities in the dynamic, coastal surf zone ecosystem, with potential management implications for several highly abundant species targeted by recreational fisheries.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"293 ","pages":"Article 105526"},"PeriodicalIF":2.1,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144695420","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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