Pub Date : 2026-01-14DOI: 10.3389/fmars.2025.1634490
Junhe Mao, Feng Li, Jiaqing Hu
Maritime accidents are lethal threats to lives, economies, and the environment as a result of which there is a need to develop advanced prediction models for early risk identification. In this paper, a novel framework integrated with Capsule Neural Networks (CapsNets) and a Modified Orangutan Optimization (MOO) algorithm is proposed to predict maritime accident hotspots. The CapsNet model captures spatio-temporal dependencies from the Global Maritime Distress and Safety System (GMDSS) dataset, while the MOO fine-tunes hyperparameters toward maximizing model accuracy and generalization. Experimental results suggest that the framework works exceedingly well against the baseline models by achieving an accuracy of 91.2%, while improving precision and recall, and reducing error rates on the contrary. Geospatial heatmaps and decision boundary visualizations strengthen the claim regarding the model’s capacity to identify high-hazard zones and clearly categorize incident types. Compelling case studies illustrate its potential for reducing response time through proactive monitoring and preparedness, which is possible only through integrating information with prediction methods. The study takes maritime safety analytics into a very intelligent and data-driven domain by overcoming shortcomings of existing predictive methods. The framework opens the door to the future integration into rescue resource planning systems, where predicted risk zones will inform strategies for asset deployment.
{"title":"Predictive analysis of maritime accident hotspots using capsule neural network optimized by modified orangutan optimization algorithm","authors":"Junhe Mao, Feng Li, Jiaqing Hu","doi":"10.3389/fmars.2025.1634490","DOIUrl":"https://doi.org/10.3389/fmars.2025.1634490","url":null,"abstract":"Maritime accidents are lethal threats to lives, economies, and the environment as a result of which there is a need to develop advanced prediction models for early risk identification. In this paper, a novel framework integrated with Capsule Neural Networks (CapsNets) and a Modified Orangutan Optimization (MOO) algorithm is proposed to predict maritime accident hotspots. The CapsNet model captures spatio-temporal dependencies from the Global Maritime Distress and Safety System (GMDSS) dataset, while the MOO fine-tunes hyperparameters toward maximizing model accuracy and generalization. Experimental results suggest that the framework works exceedingly well against the baseline models by achieving an accuracy of 91.2%, while improving precision and recall, and reducing error rates on the contrary. Geospatial heatmaps and decision boundary visualizations strengthen the claim regarding the model’s capacity to identify high-hazard zones and clearly categorize incident types. Compelling case studies illustrate its potential for reducing response time through proactive monitoring and preparedness, which is possible only through integrating information with prediction methods. The study takes maritime safety analytics into a very intelligent and data-driven domain by overcoming shortcomings of existing predictive methods. The framework opens the door to the future integration into rescue resource planning systems, where predicted risk zones will inform strategies for asset deployment.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"48 17 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145972152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Introduction The core eastern coastal cities of Qionghai and Wanning on Hainan Island are facing escalating pressures on their ecological integrity and biodiversity due to intensifying human activities. Methods To evaluate the regional ecological environmental quality, this study established a comprehensive assessment framework based on a systematic analysis of local ecological-geological conditions. Multiple factors across topographic, geologic, hydrologic, pedologic, and anthropogenic dimensions—including topography, stratigraphy, water and soil quality, land use, and ecosystem type—were integrated. Using the Delphi method to determine factor weights and ArcGIS for spatial analysis. Results The assessment revealed that human activity is the dominant influence. The area was classified into four ecological quality categories: excellent, good, moderate, and poor. Notably, key coastal aquaculture zones such as Wancheng Town, Dongao Town, and Xiaohai Bay in Wanning were identified as having relatively poor ecological quality. Discussion/conclusion Consequently, future coastal management must prioritize regulating ecological risk in human-disturbed areas, enhancing pollution control in aquaculture, and strengthening land-use policies to foster sustained regional ecological improvement.
{"title":"Integrated assessment of ecological environment quality in the eastern coastal zone of Hainan Island (China) using GIS and the analytic hierarchy process","authors":"Kaizhe Fu, Jiyong Ma, Lin Zhou, Xiaolei Liu, Yue Gou, Mingguang He, Shiyou Zhang, Dayu Bian, Jianhua Guo","doi":"10.3389/fmars.2025.1748630","DOIUrl":"https://doi.org/10.3389/fmars.2025.1748630","url":null,"abstract":"Introduction The core eastern coastal cities of Qionghai and Wanning on Hainan Island are facing escalating pressures on their ecological integrity and biodiversity due to intensifying human activities. Methods To evaluate the regional ecological environmental quality, this study established a comprehensive assessment framework based on a systematic analysis of local ecological-geological conditions. Multiple factors across topographic, geologic, hydrologic, pedologic, and anthropogenic dimensions—including topography, stratigraphy, water and soil quality, land use, and ecosystem type—were integrated. Using the Delphi method to determine factor weights and ArcGIS for spatial analysis. Results The assessment revealed that human activity is the dominant influence. The area was classified into four ecological quality categories: excellent, good, moderate, and poor. Notably, key coastal aquaculture zones such as Wancheng Town, Dongao Town, and Xiaohai Bay in Wanning were identified as having relatively poor ecological quality. Discussion/conclusion Consequently, future coastal management must prioritize regulating ecological risk in human-disturbed areas, enhancing pollution control in aquaculture, and strengthening land-use policies to foster sustained regional ecological improvement.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"29 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145972150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-13DOI: 10.3389/fmars.2025.1706757
Zeddy T. A. Seymour, Francesco Garzon, Ze Luis Monteiro, Rachel T. Graham
Large-bodied sharks, including the tiger shark ( Galeocerdo cuvier ), play crucial roles as top predators in marine ecosystems, regulating lower trophic-level populations and connecting ecosystems across vast distances. However, elasmobranchs, particularly highly migratory species, face significant threats, with over one-third of species threatened with extinction. In the Eastern Central Atlantic (ECA), a data-poor region for sharks and rays, prolific shark fisheries have led to severe declines in elasmobranch populations, highlighting the urgent need for conservation measures. This study presents the first tracking data for tiger sharks from the region and notably Cabo Verde, describing their movements within and outside the archipelago. Fishing surveys conducted between 2016 and 2019 captured and tagged 42 tiger sharks, revealing the presence of both juvenile and adult individuals. Satellite tracking of 12 individuals showed high variability in movement patterns, with some remaining near tagging sites while others undertook long-distance migrations, including a female shark tracked on a complete return migration to Brazil, representing the second-longest recorded movement and the first double trans-Atlantic journey for the species. The study underscores the importance of Cabo Verde as a habitat for tiger sharks throughout their life cycle in the ECA including Cabo Verde and suggests large-scale connectivity of populations across the Atlantic basin. However, the presence of threats such as unregulated small-scale and industrial fishing activities poses conservation challenges. Conservation efforts should focus on implementing effective management measures, notably in critical hotspot habitats, while addressing data deficiencies to ensure the long-term viability of tiger shark populations in the region.
{"title":"Satellite tracking of tiger sharks in the Eastern Central Atlantic reveals varied space-use patterns and ocean-basin connectivity","authors":"Zeddy T. A. Seymour, Francesco Garzon, Ze Luis Monteiro, Rachel T. Graham","doi":"10.3389/fmars.2025.1706757","DOIUrl":"https://doi.org/10.3389/fmars.2025.1706757","url":null,"abstract":"Large-bodied sharks, including the tiger shark ( <jats:italic>Galeocerdo cuvier</jats:italic> ), play crucial roles as top predators in marine ecosystems, regulating lower trophic-level populations and connecting ecosystems across vast distances. However, elasmobranchs, particularly highly migratory species, face significant threats, with over one-third of species threatened with extinction. In the Eastern Central Atlantic (ECA), a data-poor region for sharks and rays, prolific shark fisheries have led to severe declines in elasmobranch populations, highlighting the urgent need for conservation measures. This study presents the first tracking data for tiger sharks from the region and notably Cabo Verde, describing their movements within and outside the archipelago. Fishing surveys conducted between 2016 and 2019 captured and tagged 42 tiger sharks, revealing the presence of both juvenile and adult individuals. Satellite tracking of 12 individuals showed high variability in movement patterns, with some remaining near tagging sites while others undertook long-distance migrations, including a female shark tracked on a complete return migration to Brazil, representing the second-longest recorded movement and the first double trans-Atlantic journey for the species. The study underscores the importance of Cabo Verde as a habitat for tiger sharks throughout their life cycle in the ECA including Cabo Verde and suggests large-scale connectivity of populations across the Atlantic basin. However, the presence of threats such as unregulated small-scale and industrial fishing activities poses conservation challenges. Conservation efforts should focus on implementing effective management measures, notably in critical hotspot habitats, while addressing data deficiencies to ensure the long-term viability of tiger shark populations in the region.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"5 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145962306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-13DOI: 10.3389/fmars.2025.1610100
Hui Wu, Yilin Cao, Yanfen Wang
Based on panel data on Land-Based Marine Pollution from 11 coastal provinces in China spanning 2012 to 2023, this study employs Fixed-Effects, Threshold Regression, and Mediation Models to investigate the impact of Environmental Regulation on Land-Based Marine Pollution. The results show that: (1) there exists an inverted U-shaped relationship between Environmental Regulation and Land-Based Marine Pollution, where regulation beyond a certain threshold continuously reduces pollution levels; (2) threshold regression analysis reveals a single threshold effect in the negative impact of Environmental Regulation on the management of Land-Based Marine Pollution; (3) mediation analysis indicates that Green Technological Innovation and Industrial Structure play a mediating role between Environmental Regulation and pollution management. Specifically, Environmental Regulation reduces Land-Based Marine Pollution by promoting Green Innovation in enterprises and facilitating Industrial upgrading. To improve the management of Land-Based Marine Pollution in China, it is recommended to appropriately strengthen Environmental Regulation intensity and encourage enterprises to engage in Green Technological Innovation and Industrial restructuring, thus balancing environmental management with economic development and providing a scientific basis for pollution control.
{"title":"A study of the impact of environmental regulation on land-based marine pollution—evidence from 11 coastal provinces in China","authors":"Hui Wu, Yilin Cao, Yanfen Wang","doi":"10.3389/fmars.2025.1610100","DOIUrl":"https://doi.org/10.3389/fmars.2025.1610100","url":null,"abstract":"Based on panel data on Land-Based Marine Pollution from 11 coastal provinces in China spanning 2012 to 2023, this study employs Fixed-Effects, Threshold Regression, and Mediation Models to investigate the impact of Environmental Regulation on Land-Based Marine Pollution. The results show that: (1) there exists an inverted U-shaped relationship between Environmental Regulation and Land-Based Marine Pollution, where regulation beyond a certain threshold continuously reduces pollution levels; (2) threshold regression analysis reveals a single threshold effect in the negative impact of Environmental Regulation on the management of Land-Based Marine Pollution; (3) mediation analysis indicates that Green Technological Innovation and Industrial Structure play a mediating role between Environmental Regulation and pollution management. Specifically, Environmental Regulation reduces Land-Based Marine Pollution by promoting Green Innovation in enterprises and facilitating Industrial upgrading. To improve the management of Land-Based Marine Pollution in China, it is recommended to appropriately strengthen Environmental Regulation intensity and encourage enterprises to engage in Green Technological Innovation and Industrial restructuring, thus balancing environmental management with economic development and providing a scientific basis for pollution control.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"48 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145962353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-13DOI: 10.3389/fmars.2025.1739630
Eric P. Chassignet, Xiaobiao Xu
Current feedback affects surface motions and the numerical experiments presented in this paper highlight its importance when modeling the Gulf Stream. This is not a new notion, but its implementation in the high-resolution 1/50° North and Equatorial Atlantic HYCOM model configuration not only allows us to quantify its impact on the Gulf Stream pathway and variability via detailed comparisons to in-situ and altimetry data, but also to evaluate the latest mean dynamic topography derived from combining altimeter and satellite gravity data, drifters, and hydrological profiles. Introduction of the current feedback induces an “eddy-killing” effect that can reduce the level of eddy kinetic energy (EKE) in the model by as much as 30%, but this drop in EKE can also be compensated by decreasing the model’s explicit viscosity accordingly. The current feedback is most effective at damping energy at scales above 50–60 km while the reduction in explicit viscosity leads to an increase in small-scale energy. Addition of the current feedback also does result in a much more realistic distribution of the sea surface height variability and the resulting mean field. The detailed comparison of the model results to altimeter data and in-situ measurements leads us to state that the latest mean dynamic topography from CNES-CLS underestimates the maximum Gulf Stream velocity by approximately 10% and that the representation of the shelf circulation may be underestimated.
{"title":"Impact of wind stress formulation on Gulf Stream pathway and variability","authors":"Eric P. Chassignet, Xiaobiao Xu","doi":"10.3389/fmars.2025.1739630","DOIUrl":"https://doi.org/10.3389/fmars.2025.1739630","url":null,"abstract":"Current feedback affects surface motions and the numerical experiments presented in this paper highlight its importance when modeling the Gulf Stream. This is not a new notion, but its implementation in the high-resolution 1/50° North and Equatorial Atlantic HYCOM model configuration not only allows us to quantify its impact on the Gulf Stream pathway and variability via detailed comparisons to in-situ and altimetry data, but also to evaluate the latest mean dynamic topography derived from combining altimeter and satellite gravity data, drifters, and hydrological profiles. Introduction of the current feedback induces an “eddy-killing” effect that can reduce the level of eddy kinetic energy (EKE) in the model by as much as 30%, but this drop in EKE can also be compensated by decreasing the model’s explicit viscosity accordingly. The current feedback is most effective at damping energy at scales above 50–60 km while the reduction in explicit viscosity leads to an increase in small-scale energy. Addition of the current feedback also does result in a much more realistic distribution of the sea surface height variability and the resulting mean field. The detailed comparison of the model results to altimeter data and <jats:italic>in-situ</jats:italic> measurements leads us to state that the latest mean dynamic topography from CNES-CLS underestimates the maximum Gulf Stream velocity by approximately 10% and that the representation of the shelf circulation may be underestimated.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"86 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145962304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-13DOI: 10.3389/fmars.2025.1718289
Mark Henry F. De Leon, Dinah Grace D. Bienes, Mary Jessa Bell B. Pagapulan, Emelyn Joy G. Mameloco, Vyenge Erre D. Gayosa, Fredson H. Huervana, Carmelo S. del Castillo, Rex Ferdinand M. Traifalgar
The expansion and intensification of aquaculture have been widely adopted to support large-scale production, creating a reliance on high-protein feed ingredients such as soybean meal (SBM) and fish meal (FM). These ingredients, however, are costly and unsustainable, emphasizing the need for alternative plant-based protein sources for aquafeeds. This study assessed the nutritional and feed value of fermented rice bran meal (FRBM) as a substitute for SBM in the diet of tilapia ( Oreochromis niloticus ) fingerlings. Five diets were formulated with FRBM replacing SBM at 0%, 25%, 50%, 75%, and 100%, and were fed to fingerlings over a 60-day period. Results showed that FRBM could fully replace SBM, with growth-promoting effects particularly observed at 25% replacement. Survival, percentage weight gain, feed conversion ratio (FCR), and specific growth rate (SGR) did not differ significantly among the treatments with varying FRBM levels. No significant differences in carcass composition (protein, lipid, and ash) were observed among tilapia fed with diets containing FRBM replacement. The apparent protein and dry matter digestibility coefficients of FRBM are 91.52% and 66.67%, respectively. Histological examination also revealed no intestinal abnormalities, even at the highest level of FRBM inclusion. Overall, the findings suggest that solid-state fermented rice bran can fully replace soybean meal in the diet of O. niloticus . In addition, its use presents a practical option to help meet the growing protein requirements in aquafeeds and to promote the sustainable expansion of tilapia aquaculture.
{"title":"Fermentation of rice milling by-products can completely replace soybean meal in the diet of Oreochromis niloticus fingerlings","authors":"Mark Henry F. De Leon, Dinah Grace D. Bienes, Mary Jessa Bell B. Pagapulan, Emelyn Joy G. Mameloco, Vyenge Erre D. Gayosa, Fredson H. Huervana, Carmelo S. del Castillo, Rex Ferdinand M. Traifalgar","doi":"10.3389/fmars.2025.1718289","DOIUrl":"https://doi.org/10.3389/fmars.2025.1718289","url":null,"abstract":"The expansion and intensification of aquaculture have been widely adopted to support large-scale production, creating a reliance on high-protein feed ingredients such as soybean meal (SBM) and fish meal (FM). These ingredients, however, are costly and unsustainable, emphasizing the need for alternative plant-based protein sources for aquafeeds. This study assessed the nutritional and feed value of fermented rice bran meal (FRBM) as a substitute for SBM in the diet of tilapia ( <jats:italic>Oreochromis niloticus</jats:italic> ) fingerlings. Five diets were formulated with FRBM replacing SBM at 0%, 25%, 50%, 75%, and 100%, and were fed to fingerlings over a 60-day period. Results showed that FRBM could fully replace SBM, with growth-promoting effects particularly observed at 25% replacement. Survival, percentage weight gain, feed conversion ratio (FCR), and specific growth rate (SGR) did not differ significantly among the treatments with varying FRBM levels. No significant differences in carcass composition (protein, lipid, and ash) were observed among tilapia fed with diets containing FRBM replacement. The apparent protein and dry matter digestibility coefficients of FRBM are 91.52% and 66.67%, respectively. Histological examination also revealed no intestinal abnormalities, even at the highest level of FRBM inclusion. Overall, the findings suggest that solid-state fermented rice bran can fully replace soybean meal in the diet of <jats:italic>O. niloticus</jats:italic> . In addition, its use presents a practical option to help meet the growing protein requirements in aquafeeds and to promote the sustainable expansion of tilapia aquaculture.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"26 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145962305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-13DOI: 10.3389/fmars.2025.1674064
Bingjie Xiang, Kai Tang, Chaopeng Li, Xiaochun Cao
Sea surface temperature (SST) serves as a critical indicator for assessing marine ecosystem health. Given the increasing human exploitation of marine resources, accurate SST prediction has garnered significant attention. While existing neural network based approaches effectively capture spatio temporal dependencies within SST data, they often suffer from high computational complexity. To address this, we propose TFLinear, a lightweight SST prediction model that incorporates a novel Residual Temporal Frequency (RTF) module which combines residual linking, depthwise separable convolution, and fast Fourier transform (FFT) into the DLinear framework. The method operates in three key stages: spatial feature extraction via depthwise separable convolution, time frequency decoupling of SST sequences using FFT to isolate trend, seasonal, and transient components, and multi step prediction through dedicated linear channels followed by component wise fusion. We evaluated TFLinear using OSTIA SST data from the East China Sea for 1 to 10 days forecasts, comparing it against state of the art benchmarks. Results show that TFLinear achieves superior performance in MAE, RMSE, and R², with improvements of 7.9% to 23%, while maintaining significantly lower computational cost — demonstrating strong potential for efficient and accurate SST forecasting in practical scenarios.
{"title":"High precision lightweight prediction of short term sea surface temperature in the East China Sea: TFLinear model","authors":"Bingjie Xiang, Kai Tang, Chaopeng Li, Xiaochun Cao","doi":"10.3389/fmars.2025.1674064","DOIUrl":"https://doi.org/10.3389/fmars.2025.1674064","url":null,"abstract":"Sea surface temperature (SST) serves as a critical indicator for assessing marine ecosystem health. Given the increasing human exploitation of marine resources, accurate SST prediction has garnered significant attention. While existing neural network based approaches effectively capture spatio temporal dependencies within SST data, they often suffer from high computational complexity. To address this, we propose TFLinear, a lightweight SST prediction model that incorporates a novel Residual Temporal Frequency (RTF) module which combines residual linking, depthwise separable convolution, and fast Fourier transform (FFT) into the DLinear framework. The method operates in three key stages: spatial feature extraction via depthwise separable convolution, time frequency decoupling of SST sequences using FFT to isolate trend, seasonal, and transient components, and multi step prediction through dedicated linear channels followed by component wise fusion. We evaluated TFLinear using OSTIA SST data from the East China Sea for 1 to 10 days forecasts, comparing it against state of the art benchmarks. Results show that TFLinear achieves superior performance in MAE, RMSE, and R², with improvements of 7.9% to 23%, while maintaining significantly lower computational cost — demonstrating strong potential for efficient and accurate SST forecasting in practical scenarios.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"55 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145962303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-12DOI: 10.3389/fmars.2025.1750639
Siqi Li, Gaoyuan Sun, Jianuo Chen, Kai Liu, Ren Jiang, Xiaohua Zhou, Tianchen He
Due to the complexity of sedimentary evolution since the Last Glacial Maximum (LGM) in the Yangtze River Estuary (YRE), sedimentary responses across different regions have varied significantly, but the sedimentary record on the northern flank of the estuary remains incomplete. Here we integrate analyses of sedimentology, chemical weathering indices (CIA and K/Al), total organic carbon (TOC), and organic carbon isotopes (δ 13 C org ) from the QDQ2 core to reconstruct the regional environmental evolution from 36.1 to 8.4 cal kyr BP. Facies analysis demonstrates that QDQ2 succession documents environmental shift from terrestrial distributary channels to marine delta fronts. Sedimentary evidence of marine transgression during the Last Deglacial Period is identified, and facies shifts were driven by climate events and sea-level variations. Furthermore, the Gehu transgression did not influence the facies succession of study area. Instead, variations in CIA and K/Al ratios indicate modification in the hinterland chemical weathering intensity, likely driven by the warm climate characteristics of Marine Isotopic Stage 3a (MIS 3a).
由于末次盛冰期以来长江口沉积演化的复杂性，不同区域的沉积响应差异较大，但长江口北侧的沉积记录并不完整。结合沉积学、化学风化指标（CIA和K/Al）、总有机碳（TOC）和有机碳同位素（δ 13corg）的分析，重建了QDQ2岩心36.1 ~ 8.4 cal kyr BP的区域环境演化。相分析表明，QDQ2序列记录了从陆地分流河道到海洋三角洲前缘的环境转变。在末次冰期确定了海侵的沉积证据，其相移是由气候事件和海平面变化驱动的。此外，格湖海侵对研究区的相演替没有影响。相反，CIA和K/Al比值的变化表明内陆化学风化强度的改变，可能是由海洋同位素阶段3a （MIS 3a）的温暖气候特征驱动的。
{"title":"Sedimentary evolution and paleoclimate conditions in the Yangtze river estuary across the late Pleistocene to early Holocene","authors":"Siqi Li, Gaoyuan Sun, Jianuo Chen, Kai Liu, Ren Jiang, Xiaohua Zhou, Tianchen He","doi":"10.3389/fmars.2025.1750639","DOIUrl":"https://doi.org/10.3389/fmars.2025.1750639","url":null,"abstract":"Due to the complexity of sedimentary evolution since the Last Glacial Maximum (LGM) in the Yangtze River Estuary (YRE), sedimentary responses across different regions have varied significantly, but the sedimentary record on the northern flank of the estuary remains incomplete. Here we integrate analyses of sedimentology, chemical weathering indices (CIA and K/Al), total organic carbon (TOC), and organic carbon isotopes (δ <jats:sup>13</jats:sup> C <jats:sub>org</jats:sub> ) from the QDQ2 core to reconstruct the regional environmental evolution from 36.1 to 8.4 cal kyr BP. Facies analysis demonstrates that QDQ2 succession documents environmental shift from terrestrial distributary channels to marine delta fronts. Sedimentary evidence of marine transgression during the Last Deglacial Period is identified, and facies shifts were driven by climate events and sea-level variations. Furthermore, the Gehu transgression did not influence the facies succession of study area. Instead, variations in CIA and K/Al ratios indicate modification in the hinterland chemical weathering intensity, likely driven by the warm climate characteristics of Marine Isotopic Stage 3a (MIS 3a).","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"265 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145962334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-12DOI: 10.3389/fmars.2025.1712666
Joseph L. Kowalski, Hudson DeYoe, Kirk Cammarata, Kristina Vatcheva
The study goal was to examine the interactive physiological effects of two freshwater inflow stressors, nitrate pulses coupled with salinity decrease, on the seagrass Halodule wrightii . A microcosm experiment was designed to approximate an observed freshwater inflow event. Over a 13-day period plants were subjected to three sequential salinity drops (S35→ S23→ S15→ S5) with nitrate-nitrogen added simultaneously at 0, 30 or 60 µ M . For comparisons, the Control was no salinity change and no nitrate added denoted by S35/No N. Measurements of H. wrightii shoot production, photosynthesis, respiration, quantum efficiency, %N, C:N ratios and δ 15 N values which were made after each salinity drop revealed differing effects of low versus high N levels under S35 compared to reduced salinity. Compared to the Control at the experimental endpoint, leaf net photosynthesis: respiration (P:R) ratio decreased 3-fold for hyposalinity + High N addition (S5/High N) largely due to increased respiration. Leaf %N increased and C:N ratio decreased concomitantly with both stressors, with S5/High N having the highest %N and lowest C:N ratio. While the magnitude of the effect was related to the amount of added N at S35, there were different effects of Low versus High N at low salinity (S5). The trends of P:R ratio, leaf %N and C:N ratio are consistent with increased respiration, uptake of added N, and depletion of carbon reserves. However, δ 15 N suggested that added NO3- was taken up by leaves at S35, but not at S5. The increased %N at S5 may be due to translocation of amino acid N from rhizomes-roots to leaves. Metabolic networks were hypothesized to be regulated differently at 30 versus 60 µ M NO3- under conditions of hyposalinity. These findings add to the growing evidence that simultaneous stressors typical of substantial freshwater inflow events, hyposalinity and nitrate loading, could adversely affect H. wrightii .
本研究的目的是研究硝酸盐脉冲和盐度降低这两种淡水流入压力源对白盐海草的交互生理效应。设计了一个微观实验来模拟观测到的淡水流入事件。在13天的时间里，植物接受三次连续的盐度下降（S35→S23→S15→S5），同时添加0、30或60µM的硝酸盐氮。对照为不改变盐度，不添加以S35/ no N表示的硝酸盐。对每次降盐后黑穗槐芽部产量、光合作用、呼吸作用、量子效率、%N、C:N比率和δ 15 N值的测量显示，S35下低氮与高氮对降低盐度的影响不同。与对照组相比，低盐度+高氮（S5/高氮）处理的叶片净光合作用：呼吸（P:R）比降低了3倍，主要原因是呼吸作用增加。叶片%N升高，C:N降低，其中S5/高N的%N最高，C:N最低。虽然影响的大小与S35的施氮量有关，但低盐度下低氮与高氮的影响不同（S5）。P:R比、叶片%N和C:N的变化趋势与呼吸增加、添加氮的吸收和碳储量的消耗一致。然而，δ 15 N表明添加的NO3-在S35时被叶片吸收，而在S5时不被吸收。S5时%N的增加可能是由于氨基酸N从根茎-根向叶的转运所致。假设在低盐度条件下，代谢网络在30µM NO3-和60µM NO3-下受到不同的调节。这些发现增加了越来越多的证据，表明大量淡水流入事件的典型同时压力因素，低盐度和硝酸盐负荷，可能对赖特氏螺蛳产生不利影响。
{"title":"Interactive effects of hyposalinity and nitrate loading on growth, physiology, and nitrogen status of the seagrass, Halodule wrightii","authors":"Joseph L. Kowalski, Hudson DeYoe, Kirk Cammarata, Kristina Vatcheva","doi":"10.3389/fmars.2025.1712666","DOIUrl":"https://doi.org/10.3389/fmars.2025.1712666","url":null,"abstract":"The study goal was to examine the interactive physiological effects of two freshwater inflow stressors, nitrate pulses coupled with salinity decrease, on the seagrass <jats:italic>Halodule wrightii</jats:italic> . A microcosm experiment was designed to approximate an observed freshwater inflow event. Over a 13-day period plants were subjected to three sequential salinity drops (S35→ S23→ S15→ S5) with nitrate-nitrogen added simultaneously at 0, 30 or 60 µ <jats:italic>M</jats:italic> . For comparisons, the Control was no salinity change and no nitrate added denoted by S35/No N. Measurements of <jats:italic>H. wrightii</jats:italic> shoot production, photosynthesis, respiration, quantum efficiency, %N, C:N ratios and δ <jats:sup>15</jats:sup> N values which were made after each salinity drop revealed differing effects of low versus high N levels under S35 compared to reduced salinity. Compared to the Control at the experimental endpoint, leaf net photosynthesis: respiration (P:R) ratio decreased 3-fold for hyposalinity + High N addition (S5/High N) largely due to increased respiration. Leaf %N increased and C:N ratio decreased concomitantly with both stressors, with S5/High N having the highest %N and lowest C:N ratio. While the magnitude of the effect was related to the amount of added N at S35, there were different effects of Low versus High N at low salinity (S5). The trends of P:R ratio, leaf %N and C:N ratio are consistent with increased respiration, uptake of added N, and depletion of carbon reserves. However, δ <jats:sup>15</jats:sup> N suggested that added NO3- was taken up by leaves at S35, but not at S5. The increased %N at S5 may be due to translocation of amino acid N from rhizomes-roots to leaves. Metabolic networks were hypothesized to be regulated differently at 30 versus 60 µ <jats:italic>M</jats:italic> NO3- under conditions of hyposalinity. These findings add to the growing evidence that simultaneous stressors typical of substantial freshwater inflow events, hyposalinity and nitrate loading, could adversely affect <jats:italic>H. wrightii</jats:italic> .","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"8 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145962330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-12DOI: 10.3389/fmars.2025.1722774
Yunyun Xiang, Cifang Wu
Introduction Artificial Island social–ecological systems face escalating, compound pressures from global environmental change and intensive human activities, while conventional post-hoc restoration approaches are often insufficient to ensure long-term sustainability. We propose an ecological adaptability assessment framework to support proactive, policy-responsive adaptive management. Methods We develop a potential–constraint framework that couples scenario-based spatial modeling with explicit policy feedback. Using Dongtou District (Zhejiang Province, China) as a representative case, we quantify trade-offs between ecological resilience and development potential under alternative policy trajectories. A multidimensional indicator system—covering habitat structure, ecosystem function, socio-economic conditions, marine utilization, and governance responses—is integrated into a gridded modeling platform to identify adaptive management pathways toward 2030. Results Ecological adaptability exhibits pronounced spatial heterogeneity: high-adaptability zones align with ecological reserves, whereas low-adaptability zones cluster on densely inhabited and industrialized islands. Scenario simulations indicate that policy orientation decisively reshapes adaptability patterns. Among the evaluated pathways, the eco–economic coordination scenario delivers the most balanced configuration, improving spatial connectivity and mitigating landscape fragmentation. Discussion The proposed framework provides a transferable, policy-linked approach that bridges ecological evaluation with spatial governance, offering actionable evidence to design and prioritize island adaptive management strategies.
{"title":"Ecological adaptability assessment for adaptive management of island social–ecological systems: a potential–constraint framework applied to Dongtou District, China","authors":"Yunyun Xiang, Cifang Wu","doi":"10.3389/fmars.2025.1722774","DOIUrl":"https://doi.org/10.3389/fmars.2025.1722774","url":null,"abstract":"Introduction Artificial Island social–ecological systems face escalating, compound pressures from global environmental change and intensive human activities, while conventional post-hoc restoration approaches are often insufficient to ensure long-term sustainability. We propose an ecological adaptability assessment framework to support proactive, policy-responsive adaptive management. Methods We develop a potential–constraint framework that couples scenario-based spatial modeling with explicit policy feedback. Using Dongtou District (Zhejiang Province, China) as a representative case, we quantify trade-offs between ecological resilience and development potential under alternative policy trajectories. A multidimensional indicator system—covering habitat structure, ecosystem function, socio-economic conditions, marine utilization, and governance responses—is integrated into a gridded modeling platform to identify adaptive management pathways toward 2030. Results Ecological adaptability exhibits pronounced spatial heterogeneity: high-adaptability zones align with ecological reserves, whereas low-adaptability zones cluster on densely inhabited and industrialized islands. Scenario simulations indicate that policy orientation decisively reshapes adaptability patterns. Among the evaluated pathways, the eco–economic coordination scenario delivers the most balanced configuration, improving spatial connectivity and mitigating landscape fragmentation. Discussion The proposed framework provides a transferable, policy-linked approach that bridges ecological evaluation with spatial governance, offering actionable evidence to design and prioritize island adaptive management strategies.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"30 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145962331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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