Pub Date : 2026-02-06DOI: 10.3389/fmars.2026.1754764
Sofia Correia, Inês Ribeiro, Andreia Braga-Henriques, Pedro N. Leão, Ralph Urbatzka, Maria F. Carvalho
The constant need to search for new drugs is a major driver for the discovery of new molecules of pharmaceutical interest. Natural products (NPs) of microbial origin have been recognized for their therapeutic properties, with Actinomycetota being one of the leading groups in terms of their production. Due to the fact that Actinomycetota contain in their genomes a high number of biosynthetic gene clusters that may not be expressed under common cultures conditions, the strategy known as “one strain many compounds” (OSMAC) has emerged as an important approach to expand the chemical diversity of actinobacterial metabolites. In this work, 8 OSMAC conditions were applied to 10 actinobacterial isolates previously obtained from deep-sea samples collected at Madeira and Azores archipelagos, Portugal, in an attempt to activate silent biosynthetic gene clusters capable of producing new NPs. Organic extracts from the isolates grown under the different conditions (80 in total) were tested for their antimicrobial, anticancer and anti-inflammatory activities, revealing 11 extracts that inhibited the growth of Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Salmonella typhimurium or Candida albicans , and 9 extracts that reduced the cellular viability of T-47D or HepG2 cancer cells, while no anti-inflammatory activity was observed. Metabolomic profile of the actinobacterial extracts revealed metabolites matching known NPs, as well as features suggestive of previously unreported compounds (15 in total). This study demonstrated that the OSMAC approach is effective in modulating secondary metabolism in Actinomycetota and is consequently a useful resource for the discovery of new molecules with biotechnological potential.
{"title":"Exploring deep-sea Actinomycetota chemical diversity by using the OSMAC approach","authors":"Sofia Correia, Inês Ribeiro, Andreia Braga-Henriques, Pedro N. Leão, Ralph Urbatzka, Maria F. Carvalho","doi":"10.3389/fmars.2026.1754764","DOIUrl":"https://doi.org/10.3389/fmars.2026.1754764","url":null,"abstract":"The constant need to search for new drugs is a major driver for the discovery of new molecules of pharmaceutical interest. Natural products (NPs) of microbial origin have been recognized for their therapeutic properties, with Actinomycetota being one of the leading groups in terms of their production. Due to the fact that Actinomycetota contain in their genomes a high number of biosynthetic gene clusters that may not be expressed under common cultures conditions, the strategy known as “one strain many compounds” (OSMAC) has emerged as an important approach to expand the chemical diversity of actinobacterial metabolites. In this work, 8 OSMAC conditions were applied to 10 actinobacterial isolates previously obtained from deep-sea samples collected at Madeira and Azores archipelagos, Portugal, in an attempt to activate silent biosynthetic gene clusters capable of producing new NPs. Organic extracts from the isolates grown under the different conditions (80 in total) were tested for their antimicrobial, anticancer and anti-inflammatory activities, revealing 11 extracts that inhibited the growth of <jats:italic>Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Salmonella typhimurium</jats:italic> or <jats:italic>Candida albicans</jats:italic> , and 9 extracts that reduced the cellular viability of T-47D or HepG2 cancer cells, while no anti-inflammatory activity was observed. Metabolomic profile of the actinobacterial extracts revealed metabolites matching known NPs, as well as features suggestive of previously unreported compounds (15 in total). This study demonstrated that the OSMAC approach is effective in modulating secondary metabolism in Actinomycetota and is consequently a useful resource for the discovery of new molecules with biotechnological potential.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"364 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146129431","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 : 2026-02-06DOI: 10.3389/fmars.2026.1765685
Erchun He, HoGeun Jang, Chunfeng Zhang
Marine fisheries play a dual role in global warming as both a “carbon source” and “carbon sink.” This study analyzed carbon emissions from marine fisheries in Shandong Province from 2010 to 2022 by integrating carbon accounting, extended Kaya-LMDI decomposition, and System Dynamics (SD) modeling. The results reveal a distinct temporal trend characterized by an initial increase followed by a gradual decline in net carbon emissions, while marine carbon sinks increased steadily over the study period. Marine capture fisheries consistently remained the dominant source of total carbon emissions. Decomposition analysis reveals that economic scale and population were the primary drivers of carbon emission growth, while carbon intensity exerted a smaller but positive effect, whereas improvements in energy intensity and industrial structure contribute to emission reduction, highlighting the importance of energy efficiency improvement and industrial structural adjustment. Using a validated SD model to project trends from 2023 to 2035, we simulated three scenarios: Baseline (BS), High-Growth (HG), and Low-Carbon Development (LD) scenarios. The results show that the low-carbon development scenario achieves the most pronounced reduction in net carbon emissions, driven by simultaneous declines in capture emissions and a strong enhancement of carbon sink capacity from shellfish and algae aquaculture. In contrast, the baseline and high-growth scenarios exhibit relatively weaker mitigation effects. Overall, this study provides quantitative evidence and a strategic roadmap for advancing the green, sustainable transition of marine fisheries in Shandong Province, China.
{"title":"Integrated carbon emissions modelling and scenario analysis of marine fisheries in Shandong Province, China","authors":"Erchun He, HoGeun Jang, Chunfeng Zhang","doi":"10.3389/fmars.2026.1765685","DOIUrl":"https://doi.org/10.3389/fmars.2026.1765685","url":null,"abstract":"Marine fisheries play a dual role in global warming as both a “carbon source” and “carbon sink.” This study analyzed carbon emissions from marine fisheries in Shandong Province from 2010 to 2022 by integrating carbon accounting, extended Kaya-LMDI decomposition, and System Dynamics (SD) modeling. The results reveal a distinct temporal trend characterized by an initial increase followed by a gradual decline in net carbon emissions, while marine carbon sinks increased steadily over the study period. Marine capture fisheries consistently remained the dominant source of total carbon emissions. Decomposition analysis reveals that economic scale and population were the primary drivers of carbon emission growth, while carbon intensity exerted a smaller but positive effect, whereas improvements in energy intensity and industrial structure contribute to emission reduction, highlighting the importance of energy efficiency improvement and industrial structural adjustment. Using a validated SD model to project trends from 2023 to 2035, we simulated three scenarios: Baseline (BS), High-Growth (HG), and Low-Carbon Development (LD) scenarios. The results show that the low-carbon development scenario achieves the most pronounced reduction in net carbon emissions, driven by simultaneous declines in capture emissions and a strong enhancement of carbon sink capacity from shellfish and algae aquaculture. In contrast, the baseline and high-growth scenarios exhibit relatively weaker mitigation effects. Overall, this study provides quantitative evidence and a strategic roadmap for advancing the green, sustainable transition of marine fisheries in Shandong Province, China.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"11 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146129308","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 : 2026-02-06DOI: 10.3389/fmars.2026.1632093
Jiajun Yuan, Yongze Li, Zhaohui Cheng, Xiong Sun, Dazhao Liu
Mangrove forests in southern China’s Gaoqiao Mangrove National Nature Reserve (Guangdong–Guangxi border) have undergone significant decline followed by partial recovery, driven by human activities and conservation efforts. Traditional monitoring methods struggle to capture their complex spatiotemporal dynamics. This study develops a practical two-stage deep learning framework: an enhanced U-Net with Squeeze-and-Excitation (SE) and Convolutional Block Attention Module (CBAM) first extracts high-quality annual mangrove masks from multi-temporal Landsat imagery (1993–2023), achieving IoU = 0.815 and F1-score = 0.928. These masks are then used for spatiotemporal forecasting, with U-Net–ConvLSTM recommended as the primary architecture due to its excellent balance of accuracy, simplicity, and computational efficiency. An optional asymmetric Ecological Constraint Loss (ECOLOSS) can be added to form the ConvLSTM+ECOLOSS variant, providing marginal additional accuracy (IoU = 0.793 vs. 0.787, MAE = 6.70% vs. 6.83%) on the test period (2019–2023) by acting mainly as an ecological safeguard against unrealistic long-term runaway trends. Forecasts for 2024–2026 indicate continued slow recovery under current management. The U-Net–ConvLSTM pipeline offers a transparent and efficient tool for operational mangrove monitoring and conservation planning in subtropical China.
在人类活动和保护努力的推动下，中国南部高桥红树林国家级自然保护区（粤桂交界）的红树林经历了明显的减少和部分恢复。传统的监测方法很难捕捉到它们复杂的时空动态。本研究开发了一个实用的两阶段深度学习框架：首先，采用压缩激励（SE）和卷积块注意模块（CBAM）的增强型U-Net从1993-2023年的多时段Landsat图像中提取高质量的年度红树林掩模，获得IoU = 0.815和F1-score = 0.928。然后将这些掩模用于时空预测，由于U-Net-ConvLSTM在准确性、简单性和计算效率方面取得了良好的平衡，因此推荐将其作为主要架构。可选择的不对称生态约束损失（ECOLOSS）可以加入到ConvLSTM+ECOLOSS变体中，在测试期间（2019-2023年）提供边际额外精度（IoU = 0.793 vs. 0.787, MAE = 6.70% vs. 6.83%），主要作为对不现实的长期失控趋势的生态保障。对2024-2026年的预测表明，在目前的管理下，复苏将继续缓慢。U-Net-ConvLSTM管道为中国亚热带红树林的监测和保护规划提供了一个透明和有效的工具。
{"title":"Deep learning for mangrove change prediction: Gaoqiao Mangrove, China","authors":"Jiajun Yuan, Yongze Li, Zhaohui Cheng, Xiong Sun, Dazhao Liu","doi":"10.3389/fmars.2026.1632093","DOIUrl":"https://doi.org/10.3389/fmars.2026.1632093","url":null,"abstract":"Mangrove forests in southern China’s Gaoqiao Mangrove National Nature Reserve (Guangdong–Guangxi border) have undergone significant decline followed by partial recovery, driven by human activities and conservation efforts. Traditional monitoring methods struggle to capture their complex spatiotemporal dynamics. This study develops a practical two-stage deep learning framework: an enhanced U-Net with Squeeze-and-Excitation (SE) and Convolutional Block Attention Module (CBAM) first extracts high-quality annual mangrove masks from multi-temporal Landsat imagery (1993–2023), achieving IoU = 0.815 and F1-score = 0.928. These masks are then used for spatiotemporal forecasting, with U-Net–ConvLSTM recommended as the primary architecture due to its excellent balance of accuracy, simplicity, and computational efficiency. An optional asymmetric Ecological Constraint Loss (ECOLOSS) can be added to form the ConvLSTM+ECOLOSS variant, providing marginal additional accuracy (IoU = 0.793 vs. 0.787, MAE = 6.70% vs. 6.83%) on the test period (2019–2023) by acting mainly as an ecological safeguard against unrealistic long-term runaway trends. Forecasts for 2024–2026 indicate continued slow recovery under current management. The U-Net–ConvLSTM pipeline offers a transparent and efficient tool for operational mangrove monitoring and conservation planning in subtropical China.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"91 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146129430","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 : 2026-02-06DOI: 10.3389/fmars.2026.1714658
Myounghee Kang, Hyeon Kim, Jung-Hoon Kang, Jihoon Jung, Dongha Kang, Fredrich Simanungkalit, Somang Song, Joohyang Kim, Yeseul Kim, SungHyun Nam, Dong-Jin Kang
Understanding the spatial dynamics of tuna fisheries in relation to prey biomass and environmental variability is crucial for sustainable management in the Indian Ocean; however, the direct links between tuna catches and prey biomass remain insufficiently resolved. This study examined the relationships between prey biomass and catches of skipjack, bigeye, and yellowfin tuna, together with their spatial and environmental drivers in the western Indian Ocean, by integrating acoustic surveys (38 kHz), zooplankton sampling, Indian Ocean Tuna Commission catch records, and satellite- and in situ -derived environmental data. Temperature, salinity, dissolved oxygen, and chlorophyll- a were analyzed at upper (47.4 m) and lower (130.7 m) depths of the thermocline. Tuna catches were highest in equatorial and northwestern regions, coinciding with elevated prey biomass, increased zooplankton density, and favorable environmental conditions. Catch patterns revealed depth-dependent environmental preferences, with warmer and more productive conditions favored at 47.4 m and cooler, high-salinity, and low-productivity conditions at 130.7 m, along with a pronounced spatial structure characterized by persistent high-catch zones in the northern and western regions. Despite limitations in sampling resolution and reliance on fishery-dependent data, this integrated approach provides valuable insights for ecosystem-based management of tropical tuna fisheries under changing oceanographic conditions.
{"title":"First integrated analysis of acoustic, biological, and environmental factors influencing tropical tuna in the western Indian Ocean","authors":"Myounghee Kang, Hyeon Kim, Jung-Hoon Kang, Jihoon Jung, Dongha Kang, Fredrich Simanungkalit, Somang Song, Joohyang Kim, Yeseul Kim, SungHyun Nam, Dong-Jin Kang","doi":"10.3389/fmars.2026.1714658","DOIUrl":"https://doi.org/10.3389/fmars.2026.1714658","url":null,"abstract":"Understanding the spatial dynamics of tuna fisheries in relation to prey biomass and environmental variability is crucial for sustainable management in the Indian Ocean; however, the direct links between tuna catches and prey biomass remain insufficiently resolved. This study examined the relationships between prey biomass and catches of skipjack, bigeye, and yellowfin tuna, together with their spatial and environmental drivers in the western Indian Ocean, by integrating acoustic surveys (38 kHz), zooplankton sampling, Indian Ocean Tuna Commission catch records, and satellite- and <jats:italic>in situ</jats:italic> -derived environmental data. Temperature, salinity, dissolved oxygen, and chlorophyll- <jats:italic>a</jats:italic> were analyzed at upper (47.4 m) and lower (130.7 m) depths of the thermocline. Tuna catches were highest in equatorial and northwestern regions, coinciding with elevated prey biomass, increased zooplankton density, and favorable environmental conditions. Catch patterns revealed depth-dependent environmental preferences, with warmer and more productive conditions favored at 47.4 m and cooler, high-salinity, and low-productivity conditions at 130.7 m, along with a pronounced spatial structure characterized by persistent high-catch zones in the northern and western regions. Despite limitations in sampling resolution and reliance on fishery-dependent data, this integrated approach provides valuable insights for ecosystem-based management of tropical tuna fisheries under changing oceanographic conditions.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"303 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146129309","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 : 2026-02-06DOI: 10.3389/fmars.2026.1714561
Alexander Konik, Alexander Osadchiev
River plumes are important parts of the land–ocean matter fluxes and provide the key stage of transformation of river discharge and river-borne matter in the sea. However, both the plume-sea mixing budget and the ultimate fate of continental discharge in the open sea remain poorly understood. In this study, we analyze the GLORYS12 ocean reanalysis data to assess structure and variability of the 10 largest river plumes in the World Ocean. We quantify the interrelated characteristics of plume-sea interaction, namely, (1) response of a river plume to variability of river discharge, (2) residence time of river water in a river plume, (3) mixing intensity at plume-sea frontal zone. Based on these characteristics, we distinguish three different types of large river plumes in relation to their horizontal advection and vertical mixing with ambient seawater. The opposite ends of this classification are illustrated by the Amazon plume, which is shallow and occupies wide area due to reduced vertical mixing, and the Changjiang and St. Lawrence plumes, which have deep penetration, albeit small area due to strong vertical mixing near the river mouths. Our results aim to contribute to our understanding of how river discharge merges with and alters ambient shelf and ocean waters. It provides new insights into the spreading and mixing patterns of river plumes formed by diverse river systems.
{"title":"Spreading and mixing of large river plumes in the World Ocean","authors":"Alexander Konik, Alexander Osadchiev","doi":"10.3389/fmars.2026.1714561","DOIUrl":"https://doi.org/10.3389/fmars.2026.1714561","url":null,"abstract":"River plumes are important parts of the land–ocean matter fluxes and provide the key stage of transformation of river discharge and river-borne matter in the sea. However, both the plume-sea mixing budget and the ultimate fate of continental discharge in the open sea remain poorly understood. In this study, we analyze the GLORYS12 ocean reanalysis data to assess structure and variability of the 10 largest river plumes in the World Ocean. We quantify the interrelated characteristics of plume-sea interaction, namely, (1) response of a river plume to variability of river discharge, (2) residence time of river water in a river plume, (3) mixing intensity at plume-sea frontal zone. Based on these characteristics, we distinguish three different types of large river plumes in relation to their horizontal advection and vertical mixing with ambient seawater. The opposite ends of this classification are illustrated by the Amazon plume, which is shallow and occupies wide area due to reduced vertical mixing, and the Changjiang and St. Lawrence plumes, which have deep penetration, albeit small area due to strong vertical mixing near the river mouths. Our results aim to contribute to our understanding of how river discharge merges with and alters ambient shelf and ocean waters. It provides new insights into the spreading and mixing patterns of river plumes formed by diverse river systems.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"29 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146129307","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 Coastal zones in bay cities are characterized by high population density, concentrated economic activities, and integrated socio-ecological systems. The dynamic interaction between industrial structural evolution and coastal development in such areas exerts profound impacts on both regional economic growth and ecological sustainability, making it critical to clarify their correlation. Methods By integrating historical marine maps (1958–2020) and remote sensing images (1986–2020) of Xiamen Bay, we extracted the coastline length and utilization data of Xiamen (a typical bay city). Artificial coastlines were categorized into four types based on their functional attributes. The Spearman rank correlation coefficient was then applied to analyze the relationships between coastline length, utilization type, and urbanization indicators, linking these variables to the structure of the primary, secondary, and tertiary industries. Results and Discussion The results indicate that: 1) From 1958 to 2020, the natural coastline length of Xiamen Bay decreased by 283.57 km, accompanied by continuous expansion of artificial coastlines. Specifically, First-type artificial coastline increased by 152.73 km (1958–2002) but decreased by 134.48 km (2002–2020); Second and third type coastlines expanded by 117.07 km and 154.61 km respectively; Fourth-type coastline emerged after 2002 and reached 23.23 km in 2020. 2) At the regional scale, First-type coastline expansion showed a phased positive correlation with the primary industry; Second and third type coastline development was positively correlated with the secondary and tertiary industries (but negatively correlated with the primary industry). 3) The evolution of Xiamen’s coastal zone has shifted from a single economic benefit orientation to a synergistic “economic–ecological–social” model, corresponding to four stages: agricultural reclamation-dominated, initial export-oriented economy, bay-type city construction, and high-quality development transition. Notably, this shift is closely tied to industrial structure adjustments, providing a reference for bay cities to balance economic growth and coastal ecological protection.
{"title":"Coupling relationship of industrial structure and coastal utilization in stage-specific development of urban bay: a case study of Xiamen, China (1958–2020)","authors":"Weida Lin, Fangfang Shu, Fusheng Luo, Yunpeng Lin, Yuting Lin, Zhijie Chen, Yunhai Li","doi":"10.3389/fmars.2026.1767737","DOIUrl":"https://doi.org/10.3389/fmars.2026.1767737","url":null,"abstract":"Introduction Coastal zones in bay cities are characterized by high population density, concentrated economic activities, and integrated socio-ecological systems. The dynamic interaction between industrial structural evolution and coastal development in such areas exerts profound impacts on both regional economic growth and ecological sustainability, making it critical to clarify their correlation. Methods By integrating historical marine maps (1958–2020) and remote sensing images (1986–2020) of Xiamen Bay, we extracted the coastline length and utilization data of Xiamen (a typical bay city). Artificial coastlines were categorized into four types based on their functional attributes. The Spearman rank correlation coefficient was then applied to analyze the relationships between coastline length, utilization type, and urbanization indicators, linking these variables to the structure of the primary, secondary, and tertiary industries. Results and Discussion The results indicate that: 1) From 1958 to 2020, the natural coastline length of Xiamen Bay decreased by 283.57 km, accompanied by continuous expansion of artificial coastlines. Specifically, First-type artificial coastline increased by 152.73 km (1958–2002) but decreased by 134.48 km (2002–2020); Second and third type coastlines expanded by 117.07 km and 154.61 km respectively; Fourth-type coastline emerged after 2002 and reached 23.23 km in 2020. 2) At the regional scale, First-type coastline expansion showed a phased positive correlation with the primary industry; Second and third type coastline development was positively correlated with the secondary and tertiary industries (but negatively correlated with the primary industry). 3) The evolution of Xiamen’s coastal zone has shifted from a single economic benefit orientation to a synergistic “economic–ecological–social” model, corresponding to four stages: agricultural reclamation-dominated, initial export-oriented economy, bay-type city construction, and high-quality development transition. Notably, this shift is closely tied to industrial structure adjustments, providing a reference for bay cities to balance economic growth and coastal ecological protection.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"130 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146129305","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 : 2026-02-06DOI: 10.3389/fmars.2026.1774551
Runfa Xing, Lichuan Zhang, Bing Huang, Guangyao Han, Lu Liu
Underwater docking of autonomous underwater vehicles (AUVs) was typically dependent on the complete visual detection of markers. When markers were only partially visible due to occlusion or departure from the field of view, conventional localization methods based on complete features were rendered ineffective, resulting in the interruption of docking operations. To address this limitation, an enhanced orientation-aware method based on a spatiotemporal attention convolutional neural network (CNN) was proposed in this study. The core of this method was a dual-path feature fusion architecture: discriminative features of visible marker segments were extracted from single frames by the spatial path, while the temporal path was employed to aggregate features across consecutive frames, thereby compensating for the insufficiency of single-frame information. These two pathways were adaptively fused through a spatiotemporal attention module, which was designed to dynamically focus on the most informative cues. Consequently, robust qualitative judgment of the marker’s relative orientation was achieved. Experimental validation conducted in underwater environments demonstrated that stable orientation awareness was maintained by the proposed method even under conditions where the marker was severely off-center or largely obscured. This approach was shown to significantly extend the initial capture range for AUV docking guidance, and the robustness and operational continuity of the system under extreme visual conditions were effectively enhanced.
{"title":"A spatio-temporal attention enhanced CNN method for marker localization in AUV docking","authors":"Runfa Xing, Lichuan Zhang, Bing Huang, Guangyao Han, Lu Liu","doi":"10.3389/fmars.2026.1774551","DOIUrl":"https://doi.org/10.3389/fmars.2026.1774551","url":null,"abstract":"Underwater docking of autonomous underwater vehicles (AUVs) was typically dependent on the complete visual detection of markers. When markers were only partially visible due to occlusion or departure from the field of view, conventional localization methods based on complete features were rendered ineffective, resulting in the interruption of docking operations. To address this limitation, an enhanced orientation-aware method based on a spatiotemporal attention convolutional neural network (CNN) was proposed in this study. The core of this method was a dual-path feature fusion architecture: discriminative features of visible marker segments were extracted from single frames by the spatial path, while the temporal path was employed to aggregate features across consecutive frames, thereby compensating for the insufficiency of single-frame information. These two pathways were adaptively fused through a spatiotemporal attention module, which was designed to dynamically focus on the most informative cues. Consequently, robust qualitative judgment of the marker’s relative orientation was achieved. Experimental validation conducted in underwater environments demonstrated that stable orientation awareness was maintained by the proposed method even under conditions where the marker was severely off-center or largely obscured. This approach was shown to significantly extend the initial capture range for AUV docking guidance, and the robustness and operational continuity of the system under extreme visual conditions were effectively enhanced.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"9 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146129304","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 : 2026-02-06DOI: 10.3389/fmars.2026.1748618
Minghao Li, Guifang Xue
This article examines how traditional knowledge (TK) would be effectively incorporated into regulations for the exploitation of mineral resources in the International Seabed Area (Exploitation Regulations). It first synthesizes references to TK within international law and instruments, highlighting its relevance to deep-sea mining (DSM) by defining its four core elements (subject, time, content, context) and demonstrating its value in filling scientific data gaps and informing environmental decision-making. Building on this foundation, the article analyzes the current status of TK in the Exploitation Regulations, revealing its fragmented and non-binding inclusion, and identifies three incorporation challenges: definitional absence, lack of systematic implementation mechanisms and epistemic tensions with scientific paradigms. To address these challenges, it proposes a structured framework of recommendations: 1) establishing a TK identification system; 2) developing implementation mechanisms for TK guided by “use as the priority, with protection as the secondary” principle; 3) establishing a four-step integration model to synergize TK and science. The article contributes by proposing a systematic framework for TK identification and incorporation, elevating it from an ancillary information source to a governance resource on par with science in the Exploitation Regulations, providing a viable way for ecologically resilient DSM governance.
{"title":"Traditional knowledge and its incorporation in the exploitation regulations","authors":"Minghao Li, Guifang Xue","doi":"10.3389/fmars.2026.1748618","DOIUrl":"https://doi.org/10.3389/fmars.2026.1748618","url":null,"abstract":"This article examines how traditional knowledge (TK) would be effectively incorporated into regulations for the exploitation of mineral resources in the International Seabed Area (Exploitation Regulations). It first synthesizes references to TK within international law and instruments, highlighting its relevance to deep-sea mining (DSM) by defining its four core elements (subject, time, content, context) and demonstrating its value in filling scientific data gaps and informing environmental decision-making. Building on this foundation, the article analyzes the current status of TK in the Exploitation Regulations, revealing its fragmented and non-binding inclusion, and identifies three incorporation challenges: definitional absence, lack of systematic implementation mechanisms and epistemic tensions with scientific paradigms. To address these challenges, it proposes a structured framework of recommendations: 1) establishing a TK identification system; 2) developing implementation mechanisms for TK guided by “use as the priority, with protection as the secondary” principle; 3) establishing a four-step integration model to synergize TK and science. The article contributes by proposing a systematic framework for TK identification and incorporation, elevating it from an ancillary information source to a governance resource on par with science in the Exploitation Regulations, providing a viable way for ecologically resilient DSM governance.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"26 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146129306","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 : 2026-02-05DOI: 10.3389/fmars.2026.1743207
Adam Jon Andrews, Steven Brooks
Offshore energy structures introduce hard substrate to soft substrate-dominant habitats and may act as artificial reefs providing shelter and food to aggregating fish. In the Northeast Atlantic, knowledge on these effects is limited to shallow habitats in the southern North Sea. Given that effects may be misinterpreted as ‘nature positive’ contributions, or underestimated and impacting ecosystem services like fisheries, this data-gap hinders management. This is especially problematic for the rapid developments of floating offshore wind farms (OWFs), and decommissioning of floating oil and gas (O&G) platforms in deep (>100 m) habitats of Norway. In this study, we analysed the stable isotopic composition of muscle and liver and the condition of three codfishes of commercial importance (saithe; Pollachius virens , tusk; Brosme brosme and ling; Molva molva ) at a floating OWF and two floating O&G platforms off Norway to evaluate how codfish diet and habitat use may be altered by the structures. We find that differences in carbon, nitrogen and sulphur stable isotopes between offshore energy sites and control sites were lower for liver measurements (weeks prior to capture) than muscle (months prior to capture), indicating that codfish diet and habitat use was less impacted by offshore energy structures than longer-term natural feeding variation. Size explained some isotopic differences between sites in saithe, and condition differences between sites in tusk; suggesting that the diet and habitat use of the three species is not significantly impacted by offshore structures. However, we found evidence of lower condition in ling at Hywind Tampen OWF, corresponding to lower nitrogen isotope liver values in ling; that may indicate trade-offs in shelter and diet provision. Overall we highlight the need for further research on trophic effects of deep offshore energy structures to evaluate implications for management and conservation.
{"title":"Stable isotope insights into artificial reef effects of floating offshore energy structures in Norwegian North Sea codfishes","authors":"Adam Jon Andrews, Steven Brooks","doi":"10.3389/fmars.2026.1743207","DOIUrl":"https://doi.org/10.3389/fmars.2026.1743207","url":null,"abstract":"Offshore energy structures introduce hard substrate to soft substrate-dominant habitats and may act as artificial reefs providing shelter and food to aggregating fish. In the Northeast Atlantic, knowledge on these effects is limited to shallow habitats in the southern North Sea. Given that effects may be misinterpreted as ‘nature positive’ contributions, or underestimated and impacting ecosystem services like fisheries, this data-gap hinders management. This is especially problematic for the rapid developments of floating offshore wind farms (OWFs), and decommissioning of floating oil and gas (O&amp;G) platforms in deep (&gt;100 m) habitats of Norway. In this study, we analysed the stable isotopic composition of muscle and liver and the condition of three codfishes of commercial importance (saithe; <jats:italic>Pollachius virens</jats:italic> , tusk; <jats:italic>Brosme brosme</jats:italic> and ling; <jats:italic>Molva molva</jats:italic> ) at a floating OWF and two floating O&amp;G platforms off Norway to evaluate how codfish diet and habitat use may be altered by the structures. We find that differences in carbon, nitrogen and sulphur stable isotopes between offshore energy sites and control sites were lower for liver measurements (weeks prior to capture) than muscle (months prior to capture), indicating that codfish diet and habitat use was less impacted by offshore energy structures than longer-term natural feeding variation. Size explained some isotopic differences between sites in saithe, and condition differences between sites in tusk; suggesting that the diet and habitat use of the three species is not significantly impacted by offshore structures. However, we found evidence of lower condition in ling at Hywind Tampen OWF, corresponding to lower nitrogen isotope liver values in ling; that may indicate trade-offs in shelter and diet provision. Overall we highlight the need for further research on trophic effects of deep offshore energy structures to evaluate implications for management and conservation.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"12 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122044","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 : 2026-02-04DOI: 10.3389/fmars.2026.1688347
Peixiao Mao, Judith M. Schicks
The dissociation behavior of CH 4 – C 3 H 8 mixed gas hydrates in natural marine sediments is critical to global carbon storage and marine biogeochemical cycles, but the effects of sediment composition and dissociation pathways remain unclear. In this study, dissociation experiments were conducted using marine sediments from the South China Sea, including foraminifera-rich sands, mud-foraminifera sand mixtures, and muds, under controlled heating and depressurization. Hydrate dissociation dynamics and gas release were monitored using in situ and ex situ Raman spectroscopy, supplemented by microscopic observations. Our results show that dissociation of sII hydrate crystals in all sediments begins within the hydrate stability range. The morphological changes in hydrate crystal surfaces correlate with compositional shifts in sediments characterized by high heterogeneity and a broad particle-size distribution. In muddy sediments, dissociation behavior remained uniform regardless of the triggering mechanism, while hydrate crystals in foraminifera-rich sands exhibited distinct behaviors under heating compared to depressurization. Sediment composition influences gas release, although the L (CH 4 )/ S (CH 4 ) ratio remains nearly constant across all sediments. Specifically, coarse quartz particles enhance CH 4 and C 3 H 8 release, while clay minerals have negligible effects. Foraminifera-rich sands preferentially facilitate CH 4 release under heating, whereas they promote CH 4 and C 3 H 8 release under depressurization. These findings provide mechanistic and quantitative insights into sediment-carbon interactions in marine systems, with implications for sustainable carbon management and predicting ocean responses to anthropogenic and climate-driven perturbations.
天然海洋沉积物中ch4 - c3h8混合气体水合物的解离行为对全球碳储量和海洋生物地球化学循环至关重要，但沉积物组成和解离途径的影响尚不清楚。本研究利用南海海相沉积物，包括富有孔虫砂、泥-有孔虫砂混合物和泥浆，在控制加热和减压的条件下进行了解离实验。水合物解离动力学和气体释放监测使用原位和非原位拉曼光谱，辅以微观观察。我们的研究结果表明，所有沉积物中sII水合物晶体的解离开始于水合物稳定范围内。水合物晶体表面的形态变化与沉积物中具有高非均质性和宽粒度分布的成分变化有关。在泥质沉积物中，无论触发机制如何，解离行为都保持一致，而在富含有孔虫的砂中，水合物晶体在加热下的行为与减压下的行为不同。尽管L (ch4)/ S （ch4）比在所有沉积物中几乎保持恒定，但沉积物成分影响气体释放。具体来说，粗粒石英颗粒促进了ch4和c3h8的释放，而粘土矿物的影响可以忽略不计。富有孔虫砂在加热条件下有利于ch4释放，而在减压条件下有利于ch4和c3h8的释放。这些发现提供了海洋系统中沉积物-碳相互作用的机制和定量见解，对可持续碳管理和预测海洋对人为和气候驱动的扰动的反应具有重要意义。
{"title":"CH4–C3H8 mixed gas hydrate behavior in natural marine sediments: influence of sediment type and dissociation pathways","authors":"Peixiao Mao, Judith M. Schicks","doi":"10.3389/fmars.2026.1688347","DOIUrl":"https://doi.org/10.3389/fmars.2026.1688347","url":null,"abstract":"The dissociation behavior of CH <jats:sub>4</jats:sub> – C <jats:sub>3</jats:sub> H <jats:sub>8</jats:sub> mixed gas hydrates in natural marine sediments is critical to global carbon storage and marine biogeochemical cycles, but the effects of sediment composition and dissociation pathways remain unclear. In this study, dissociation experiments were conducted using marine sediments from the South China Sea, including foraminifera-rich sands, mud-foraminifera sand mixtures, and muds, under controlled heating and depressurization. Hydrate dissociation dynamics and gas release were monitored using <jats:italic>in situ</jats:italic> and <jats:italic>ex situ</jats:italic> Raman spectroscopy, supplemented by microscopic observations. Our results show that dissociation of sII hydrate crystals in all sediments begins within the hydrate stability range. The morphological changes in hydrate crystal surfaces correlate with compositional shifts in sediments characterized by high heterogeneity and a broad particle-size distribution. In muddy sediments, dissociation behavior remained uniform regardless of the triggering mechanism, while hydrate crystals in foraminifera-rich sands exhibited distinct behaviors under heating compared to depressurization. Sediment composition influences gas release, although the <jats:italic>L</jats:italic> (CH <jats:sub>4</jats:sub> )/ <jats:italic>S</jats:italic> (CH <jats:sub>4</jats:sub> ) ratio remains nearly constant across all sediments. Specifically, coarse quartz particles enhance CH <jats:sub>4</jats:sub> and C <jats:sub>3</jats:sub> H <jats:sub>8</jats:sub> release, while clay minerals have negligible effects. Foraminifera-rich sands preferentially facilitate CH <jats:sub>4</jats:sub> release under heating, whereas they promote CH <jats:sub>4</jats:sub> and C <jats:sub>3</jats:sub> H <jats:sub>8</jats:sub> release under depressurization. These findings provide mechanistic and quantitative insights into sediment-carbon interactions in marine systems, with implications for sustainable carbon management and predicting ocean responses to anthropogenic and climate-driven perturbations.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"30 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146115943","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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