Pub Date : 2026-03-11DOI: 10.3389/fmars.2026.1768972
Luiza Pasetti Fiorini, Mario Luiz Mascagni, Antonio Henrique da Fontoura Klein
Embayed beaches along rocky coasts exhibit complex shoreline dynamics driven by the interaction between wave climate variability, headland-controlled exposure, and sediment exchange within semi-enclosed cells. This study investigate four decades (1984–2023) of shoreline evolution across 12 embayed beaches along the Santa Catarina coast, southern Brazil, by integrating satellite-derived shorelines, space–time statistical analysis, hybrid wave modeling, and large-scale climate modes. Shoreline positions were extracted from Landsat imagery using the CASSIE-Shoreline algorithm and analyzed through Hovmöller diagrams and transect-based trends to diagnose chronic erosion, dynamic equilibrium, and accretionary behavior. Nearshore wave forcing was reconstructed using the BinWaves hybrid framework, combining CAWCR/CSIRO deep-water hindcasts with SWAN-based nearshore propagation. The resulting reconstruction was validated against available in situ observations. While uncertainties inherent to nearshore wave modeling in complex embayed settings are acknowledged, the approach remains robust for identifying long-term storm-wave patterns. Results reveal a bimodal storm-wave climate dominated by easterly and southerly waves, superimposed on a persistent counterclockwise rotation of the mean storm-wave direction of ~2° over four decades, reaching up to ~5.2° during spring. This directional shift increases wave exposure at northeast- and east-facing embayments, coinciding with a statistically significant increase in storm-wave frequency in these sectors, while south-facing beaches exhibit stable storm occurrence. The Southern Annular Mode (SAM) shows the strongest positive correlation with storm-wave frequency, indicating that SAM-driven variability dominates extreme-wave generation in the South Atlantic. The El Niño–Southern Oscillation (ENSO) exerts a weaker control on storm extremes and likely modulates background hydroclimatic conditions. Decadal reversals in erosion–accretion patterns observed at several south-facing beaches are consistent with large-scale modulation associated with the Atlantic Multidecadal Oscillation (AMO). Together, these results demonstrate that shoreline evolution in embayed systems is primarily governed by climate-driven variability in storm-wave direction, frequency, and clustering, rather than by changes in mean wave conditions. The integrated satellite–modeling approach provides a robust and transferable framework for assessing climate-sensitive coastal morphodynamics everywhere including in data-limited regions.
{"title":"Four decades of embayed coastline evolution assessed through the integration of remote sensing (CASSIE) and hybrid wave modeling (BinWaves) tools","authors":"Luiza Pasetti Fiorini, Mario Luiz Mascagni, Antonio Henrique da Fontoura Klein","doi":"10.3389/fmars.2026.1768972","DOIUrl":"https://doi.org/10.3389/fmars.2026.1768972","url":null,"abstract":"Embayed beaches along rocky coasts exhibit complex shoreline dynamics driven by the interaction between wave climate variability, headland-controlled exposure, and sediment exchange within semi-enclosed cells. This study investigate four decades (1984–2023) of shoreline evolution across 12 embayed beaches along the Santa Catarina coast, southern Brazil, by integrating satellite-derived shorelines, space–time statistical analysis, hybrid wave modeling, and large-scale climate modes. Shoreline positions were extracted from Landsat imagery using the CASSIE-Shoreline algorithm and analyzed through Hovmöller diagrams and transect-based trends to diagnose chronic erosion, dynamic equilibrium, and accretionary behavior. Nearshore wave forcing was reconstructed using the BinWaves hybrid framework, combining CAWCR/CSIRO deep-water hindcasts with SWAN-based nearshore propagation. The resulting reconstruction was validated against available <jats:italic>in situ</jats:italic> observations. While uncertainties inherent to nearshore wave modeling in complex embayed settings are acknowledged, the approach remains robust for identifying long-term storm-wave patterns. Results reveal a bimodal storm-wave climate dominated by easterly and southerly waves, superimposed on a persistent counterclockwise rotation of the mean storm-wave direction of ~2° over four decades, reaching up to ~5.2° during spring. This directional shift increases wave exposure at northeast- and east-facing embayments, coinciding with a statistically significant increase in storm-wave frequency in these sectors, while south-facing beaches exhibit stable storm occurrence. The Southern Annular Mode (SAM) shows the strongest positive correlation with storm-wave frequency, indicating that SAM-driven variability dominates extreme-wave generation in the South Atlantic. The El Niño–Southern Oscillation (ENSO) exerts a weaker control on storm extremes and likely modulates background hydroclimatic conditions. Decadal reversals in erosion–accretion patterns observed at several south-facing beaches are consistent with large-scale modulation associated with the Atlantic Multidecadal Oscillation (AMO). Together, these results demonstrate that shoreline evolution in embayed systems is primarily governed by climate-driven variability in storm-wave direction, frequency, and clustering, rather than by changes in mean wave conditions. The integrated satellite–modeling approach provides a robust and transferable framework for assessing climate-sensitive coastal morphodynamics everywhere including in data-limited regions.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"127 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147393326","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 : 2026-03-11DOI: 10.3389/fmars.2026.1735256
Kuria Ndungu, Caroline Mengeot, Louise Valestrand, Kai Sørensen, Andrew L. King
Seawater samples for total dissolved inorganic carbon ( CT ) and total alkalinity ( AT ) measurements of the seawater carbonate system are typically preserved with mercuric chloride (HgCl 2 ), but mercury use is globally regulated under the Minamata Convention. We tested silver nitrate (AgNO 3 ; 25 and 50 μM) as an alternative preservative for oligotrophic seawater. No significant differences ( p > 0.05) in CT were observed between HgCl 2 -treated samples (2,177 ± 2 μmol kg −1 ) and either 25 μM (2,178 ± 2 μmol kg −1 ) or 50 μM (2,177 ± 1 μmol kg −1 ) AgNO 3 treatments after a 2-day storage. Untreated samples showed a significant CT increase over the same period. After 21 days, both AgNO 3 treatments showed significantly elevated CT compared to HgCl 2 . AT remained stable across all treatments for 3 months. This initial investigation demonstrates that AgNO 3 is suitable for short-term (≤2 days) preservation, enabling shipboard carbonate chemistry analysis with simplified disposal compared to mercury-contaminated samples. Further studies with diverse marine waters are needed to establish broader applicability.
用于测量海水碳酸盐体系的总溶解无机碳（C T）和总碱度（A T）的海水样品通常用氯化汞（HgCl 2）保存，但汞的使用在全球范围内受到《水俣公约》的管制。我们测试了硝酸银（agno3； 25和50 μM）作为低营养海水的替代防腐剂。HgCl 2处理（2177±2 μmol kg - 1）的样品与25 μM（2178±2 μmol kg - 1）或50 μM(2177±1 μmol kg - 1) AgNO 3处理2 d后的C T无显著差异（p > 0.05）。未经处理的样品在同一时期显示出显著的碳水化合物增加。21天后，两种agno3处理均显示与hgcl2相比，C T显著升高。在3个月的治疗中，A - T保持稳定。这项初步研究表明，agno3适合短期（≤2天）保存，与汞污染的样品相比，可以简化处理，从而实现船上碳酸盐化学分析。需要对不同的海水进行进一步的研究，以建立更广泛的适用性。
{"title":"Silver nitrate preserves seawater carbonate chemistry for short-term storage","authors":"Kuria Ndungu, Caroline Mengeot, Louise Valestrand, Kai Sørensen, Andrew L. King","doi":"10.3389/fmars.2026.1735256","DOIUrl":"https://doi.org/10.3389/fmars.2026.1735256","url":null,"abstract":"Seawater samples for total dissolved inorganic carbon ( <jats:italic>C</jats:italic> <jats:sub>T</jats:sub> ) and total alkalinity ( <jats:italic>A</jats:italic> <jats:sub>T</jats:sub> ) measurements of the seawater carbonate system are typically preserved with mercuric chloride (HgCl <jats:sub>2</jats:sub> ), but mercury use is globally regulated under the Minamata Convention. We tested silver nitrate (AgNO <jats:sub>3</jats:sub> ; 25 and 50 μM) as an alternative preservative for oligotrophic seawater. No significant differences ( <jats:italic>p</jats:italic> &gt; 0.05) in <jats:italic>C</jats:italic> <jats:sub>T</jats:sub> were observed between HgCl <jats:sub>2</jats:sub> -treated samples (2,177 ± 2 μmol kg <jats:sup>−1</jats:sup> ) and either 25 μM (2,178 ± 2 μmol kg <jats:sup>−1</jats:sup> ) or 50 μM (2,177 ± 1 μmol kg <jats:sup>−1</jats:sup> ) AgNO <jats:sub>3</jats:sub> treatments after a 2-day storage. Untreated samples showed a significant <jats:italic>C</jats:italic> <jats:sub>T</jats:sub> increase over the same period. After 21 days, both AgNO <jats:sub>3</jats:sub> treatments showed significantly elevated <jats:italic>C</jats:italic> <jats:sub>T</jats:sub> compared to HgCl <jats:sub>2</jats:sub> . <jats:italic>A</jats:italic> <jats:sub>T</jats:sub> remained stable across all treatments for 3 months. This initial investigation demonstrates that AgNO <jats:sub>3</jats:sub> is suitable for short-term (≤2 days) preservation, enabling shipboard carbonate chemistry analysis with simplified disposal compared to mercury-contaminated samples. Further studies with diverse marine waters are needed to establish broader applicability.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"75 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147393663","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}
Coastal aquaculture ponds represent a significant contributor to economic growth and food provision, underscoring the necessity of precise spatial mapping to support sustainable resource management. Current extraction methods often rely on single-source data and are easily confused by spectral heterogeneity in complex coastal environments, leading to blurred boundaries and misclassification. To overcome these challenges, this study proposes an innovative hybrid model that combines multi-source feature stacking with a hierarchical decision-tree architecture for coarse extraction, followed by an ensemble-learning framework for fine-scale classification. Implemented on the Google Earth Engine cloud platform, the model integrates Sentinel-1 and Sentinel-2 data to leverage complementary spectral, microwave, and terrain features. Applied to the Zhoushan Archipelago in China, the approach produced a high-resolution distribution map of aquaculture ponds with clear boundaries and accurate geolocation. Compared with conventional approaches such as random forest (RF), classification regression trees (CART) and support vector machines (SVM), the proposed model achieved an overall accuracy of 87.34%, improving by 2.55% to 5.39%. The model also achieved a Kappa Coefficient of 73.82% and an F1 score of 89.46%, demonstrating its effectiveness and reliability for automated coastal aquaculture pond extraction in complex coastal environments.
{"title":"A novel hybrid model for coastal aquaculture ponds integrating hierarchical decision-tree and ensemble-learning approaches from Sentinel satellites","authors":"Xiaoyan Yang, Jianqiang Wang, Jian Gao, Pingping Liu, Xingbai Hu, Fei Zhang, Chao Chen","doi":"10.3389/fmars.2026.1778967","DOIUrl":"https://doi.org/10.3389/fmars.2026.1778967","url":null,"abstract":"Coastal aquaculture ponds represent a significant contributor to economic growth and food provision, underscoring the necessity of precise spatial mapping to support sustainable resource management. Current extraction methods often rely on single-source data and are easily confused by spectral heterogeneity in complex coastal environments, leading to blurred boundaries and misclassification. To overcome these challenges, this study proposes an innovative hybrid model that combines multi-source feature stacking with a hierarchical decision-tree architecture for coarse extraction, followed by an ensemble-learning framework for fine-scale classification. Implemented on the Google Earth Engine cloud platform, the model integrates Sentinel-1 and Sentinel-2 data to leverage complementary spectral, microwave, and terrain features. Applied to the Zhoushan Archipelago in China, the approach produced a high-resolution distribution map of aquaculture ponds with clear boundaries and accurate geolocation. Compared with conventional approaches such as random forest (RF), classification regression trees (CART) and support vector machines (SVM), the proposed model achieved an overall accuracy of 87.34%, improving by 2.55% to 5.39%. The model also achieved a Kappa Coefficient of 73.82% and an F1 score of 89.46%, demonstrating its effectiveness and reliability for automated coastal aquaculture pond extraction in complex coastal environments.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"77 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147393259","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 : 2026-03-11DOI: 10.3389/fmars.2026.1801883
Jinlei Zhang, Zehui Jiang, Xiaoran Liu
Amid global climate governance and the green and low-carbon transition of the shipping industry, China’s success in regulating shipping carbon emissions is crucial to achieving its carbon peak and carbon neutrality goals, as well as advancing international climate governance. As the world’s largest ship-owning nation and the biggest goods trading country, China plays a key role in this effort. This paper systematically examines the current situation of policy-law synergy governance for green and low-carbon shipping in China, based on the analytical framework of Rechtspolitik (legal policy objectives → legal policy instruments → alignment between objectives and instruments). This study finds that China has preliminarily established the legal policy objectives for green and low-carbon shipping, however, it suffers from insufficient quantitative indicators and lacks effective mechanisms to translate policy goals into binding legal obligations. Regarding legal policy instruments, despite the current hybrid regulatory framework incorporating both command-and-control and market-based approaches, market-based instruments have not yet played the leading role and remain confined to pilot programs or principled provisions. To enhance the effectiveness of policy-law synergy governance, this paper proposes three pathways to achieve a dynamic balance between policy flexibility and legal stability, and to enhance governance effectiveness based on the fundamental paradigm of policy-law synergy governance. Those three pathways are constructing a clearly defined policy system and introducing policies exploring the inclusion of the shipping industry into the carbon emission trading market, enacting specific law on carbon peak and carbon neutrality, and promoting the establishment of dedicated chapters on “green and low-carbon shipping” in local regulations of coastal provinces and municipalities. This paper not only provides theoretical insights and practical guidance for the policy-law synergy in green and low-carbon shipping in China, but also offers a transferable governance model for promoting the green and low-carbon transition of the shipping industry in countries at similar developmental stages and facing similar challenges.
{"title":"Bridging gaps between legal considerations and implementation: synergistic governance for China’s shipping decarbonization","authors":"Jinlei Zhang, Zehui Jiang, Xiaoran Liu","doi":"10.3389/fmars.2026.1801883","DOIUrl":"https://doi.org/10.3389/fmars.2026.1801883","url":null,"abstract":"Amid global climate governance and the green and low-carbon transition of the shipping industry, China’s success in regulating shipping carbon emissions is crucial to achieving its carbon peak and carbon neutrality goals, as well as advancing international climate governance. As the world’s largest ship-owning nation and the biggest goods trading country, China plays a key role in this effort. This paper systematically examines the current situation of policy-law synergy governance for green and low-carbon shipping in China, based on the analytical framework of Rechtspolitik (legal policy objectives → legal policy instruments → alignment between objectives and instruments). This study finds that China has preliminarily established the legal policy objectives for green and low-carbon shipping, however, it suffers from insufficient quantitative indicators and lacks effective mechanisms to translate policy goals into binding legal obligations. Regarding legal policy instruments, despite the current hybrid regulatory framework incorporating both command-and-control and market-based approaches, market-based instruments have not yet played the leading role and remain confined to pilot programs or principled provisions. To enhance the effectiveness of policy-law synergy governance, this paper proposes three pathways to achieve a dynamic balance between policy flexibility and legal stability, and to enhance governance effectiveness based on the fundamental paradigm of policy-law synergy governance. Those three pathways are constructing a clearly defined policy system and introducing policies exploring the inclusion of the shipping industry into the carbon emission trading market, enacting specific law on carbon peak and carbon neutrality, and promoting the establishment of dedicated chapters on “green and low-carbon shipping” in local regulations of coastal provinces and municipalities. This paper not only provides theoretical insights and practical guidance for the policy-law synergy in green and low-carbon shipping in China, but also offers a transferable governance model for promoting the green and low-carbon transition of the shipping industry in countries at similar developmental stages and facing similar challenges.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"8 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147393262","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 : 2026-03-11DOI: 10.3389/fmars.2026.1769593
Andrea Prófumo, Octavio R. Salazar, Carlos Angulo-Preckler, Carlos M. Duarte, Manuel Aranda, Conxita Avila
Antarctic marine invertebrates are sensitive to temperature fluctuations, and therefore vulnerable to ongoing ocean warming. To investigate molecular responses to heat stress, the benthic isopod Spinoserolis beddardi and the asteroid Diplasterias sp., both adapted to ~0 °C conditions, were used. Organisms were exposed to short-term thermal increments of +3 °C and +7 °C in controlled aquarium experiments. After one week, transcriptomes were sequenced, generating a total of 245 Gb (26 libraries) for Diplasterias sp. and 312 Gb (29 libraries) for S. beddardi . sp. De novo assemblies yielded 392,214 and 438,423 protein-coding transcripts, of which 75,983 and 65,497, respectively, had significant matches to metazoan proteins. S. beddardi showed a faster but limited response, with high transcriptional activation at +3 °C (1,140 up- and 733 down-regulated transcripts) but reduced differential expression at +7 ºC, a temperature that induced mortality and phenotypic stress. Contrarily, Diplasterias sp. displayed broader transcriptional changes increasing with temperature, with 1,175 up- and 1,128 down-regulated transcripts at +7 °C and significant differences between treatments. GO and KEGG enrichment analyses indicated that cellular structure, metabolic pathways, protein folding, and reproductive processes underpin thermal stress responses of both species. This study provides the first comparative transcriptomic insight into the heat stress responses in these two Antarctic benthic invertebrates, offering a framework to assess their resilience under projected ocean warming scenarios.
{"title":"Heat stress triggers distinct transcriptomic responses in cold-adapted Antarctic marine invertebrates","authors":"Andrea Prófumo, Octavio R. Salazar, Carlos Angulo-Preckler, Carlos M. Duarte, Manuel Aranda, Conxita Avila","doi":"10.3389/fmars.2026.1769593","DOIUrl":"https://doi.org/10.3389/fmars.2026.1769593","url":null,"abstract":"Antarctic marine invertebrates are sensitive to temperature fluctuations, and therefore vulnerable to ongoing ocean warming. To investigate molecular responses to heat stress, the benthic isopod <jats:italic>Spinoserolis beddardi</jats:italic> and the asteroid <jats:italic>Diplasterias</jats:italic> sp., both adapted to ~0 °C conditions, were used. Organisms were exposed to short-term thermal increments of +3 °C and +7 °C in controlled aquarium experiments. After one week, transcriptomes were sequenced, generating a total of 245 Gb (26 libraries) for <jats:italic>Diplasterias</jats:italic> sp. and 312 Gb (29 libraries) for <jats:italic>S. beddardi</jats:italic> . sp. <jats:italic>De novo</jats:italic> assemblies yielded 392,214 and 438,423 protein-coding transcripts, of which 75,983 and 65,497, respectively, had significant matches to metazoan proteins. <jats:italic>S. beddardi</jats:italic> showed a faster but limited response, with high transcriptional activation at +3 °C (1,140 up- and 733 down-regulated transcripts) but reduced differential expression at +7 ºC, a temperature that induced mortality and phenotypic stress. Contrarily, <jats:italic>Diplasterias</jats:italic> sp. displayed broader transcriptional changes increasing with temperature, with 1,175 up- and 1,128 down-regulated transcripts at +7 °C and significant differences between treatments. GO and KEGG enrichment analyses indicated that cellular structure, metabolic pathways, protein folding, and reproductive processes underpin thermal stress responses of both species. This study provides the first comparative transcriptomic insight into the heat stress responses in these two Antarctic benthic invertebrates, offering a framework to assess their resilience under projected ocean warming scenarios.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"7 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147393264","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 : 2026-03-11DOI: 10.3389/fmars.2026.1749044
Sulastri Arsad, Romain Gastineau, Małgorzata Bąk, Mateusz Rybak, Ewa Górecka, Claude Lemieux, Monique Turmel, Fiddy Semba Prasetiya, Christopher S. Lobban
Introduction Caloneis egena is a species of diatom originally described from Campeche Bay (Mexico) that is regarded as cosmopolitan, with several reports from the Pacific region. Methods A strain of diatom from the genus Caloneis was isolated from the Gulf of Tomini, Sulawesi (Indonesia). It was subjected to an integrated approach combining microscopy, genomic analyses, and phylogeny. Results Although looking similar to C. egena , the strain from Tomini was found to be a new species, hereby described as Caloneis paraegena sp. nov. The complete mitochondrial and plastid genomes were sequenced and annotated and represent the first organellar genomes made available for the genus Caloneis . The multigene phylogeny inferred from these results positions C. paraegena as sister to a clade that associates Caloneis fontinalis , C. silicula , and C. lewisii . Discussion A survey of the literature dedicated to C. egena led to questioning its distribution, suggesting that records from the Pacific region might, in fact, represent C. paraegena based on morphology. Because of the absence of a molecular reference for C. egena , the exact relationship between these two species remains to be verified.
{"title":"Not Caloneis egena: morphological description and complete plastid and mitochondrial genomes of Caloneis paraegena sp. nov. from the Gulf of Tomini, Indonesia","authors":"Sulastri Arsad, Romain Gastineau, Małgorzata Bąk, Mateusz Rybak, Ewa Górecka, Claude Lemieux, Monique Turmel, Fiddy Semba Prasetiya, Christopher S. Lobban","doi":"10.3389/fmars.2026.1749044","DOIUrl":"https://doi.org/10.3389/fmars.2026.1749044","url":null,"abstract":"Introduction <jats:italic>Caloneis egena</jats:italic> is a species of diatom originally described from Campeche Bay (Mexico) that is regarded as cosmopolitan, with several reports from the Pacific region. Methods A strain of diatom from the genus <jats:italic>Caloneis</jats:italic> was isolated from the Gulf of Tomini, Sulawesi (Indonesia). It was subjected to an integrated approach combining microscopy, genomic analyses, and phylogeny. Results Although looking similar to <jats:italic>C. egena</jats:italic> , the strain from Tomini was found to be a new species, hereby described as <jats:italic>Caloneis paraegena</jats:italic> sp. nov. The complete mitochondrial and plastid genomes were sequenced and annotated and represent the first organellar genomes made available for the genus <jats:italic>Caloneis</jats:italic> . The multigene phylogeny inferred from these results positions <jats:italic>C. paraegena</jats:italic> as sister to a clade that associates <jats:italic>Caloneis fontinalis</jats:italic> , <jats:italic>C. silicula</jats:italic> , and <jats:italic>C. lewisii</jats:italic> . Discussion A survey of the literature dedicated to <jats:italic>C. egena</jats:italic> led to questioning its distribution, suggesting that records from the Pacific region might, in fact, represent <jats:italic>C. paraegena</jats:italic> based on morphology. Because of the absence of a molecular reference for <jats:italic>C. egena</jats:italic> , the exact relationship between these two species remains to be verified.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"11 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147393263","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 : 2026-03-11DOI: 10.3389/fmars.2026.1739607
Andrew C. Poje, Takaya Uchida, Quentin Jamet, Luolin Sun, Thierry Penduff, Bruno Deremble, Joseph Schoonover, Megan Trapanese, Nicolas Wienders, William K. Dewar
We address the question of separating the ocean’s deterministic response to time-dependent forcing from its intrinsic chaotic variability. Ideally, one could compute the ensemble mean directly without performing numerous realizations, but this requires knowledge or closure of the second-order statistics — the classical turbulent-closure problem, here recast for a non-equilibrium, geophysical setting. Building on the ideas of nonlinear midlatitude ocean adjustment, we examine this problem using idealized quasi-geostrophic (QG) double-gyre ensembles subjected to episodic temporal variations in wind forcing. Our objective here is not to develop a subgrid parameterization of unresolved eddies, but rather to construct and test prognostic equations for the ensemble mean itself, using the simplest possible closure assumptions. We find that the performance of ensemble mean closures is highly dependent on the spatiotemporal structure of the forcing. Under slowly varying forcing, approximate closures reproduce the mean evolution reasonably well; under rapidly varying, near-zero-mean forcing, the simplest ensemble-mean closures fail, even at the level of basin-averaged total energy and enstrophy. In both regimes, the ensemble-mean response is not simply the accumulated imprint of the applied forcing, but instead appears as a continuing, non-equilibrated dialogue between the mean and eddy fields.
{"title":"Thoughts on prognostically modeling an eddying double-gyre ensemble mean","authors":"Andrew C. Poje, Takaya Uchida, Quentin Jamet, Luolin Sun, Thierry Penduff, Bruno Deremble, Joseph Schoonover, Megan Trapanese, Nicolas Wienders, William K. Dewar","doi":"10.3389/fmars.2026.1739607","DOIUrl":"https://doi.org/10.3389/fmars.2026.1739607","url":null,"abstract":"We address the question of separating the ocean’s deterministic response to time-dependent forcing from its intrinsic chaotic variability. Ideally, one could compute the ensemble mean directly without performing numerous realizations, but this requires knowledge or closure of the second-order statistics — the classical turbulent-closure problem, here recast for a non-equilibrium, geophysical setting. Building on the ideas of nonlinear midlatitude ocean adjustment, we examine this problem using idealized quasi-geostrophic (QG) double-gyre ensembles subjected to episodic temporal variations in wind forcing. Our objective here is not to develop a subgrid parameterization of unresolved eddies, but rather to construct and test prognostic equations for the ensemble mean itself, using the simplest possible closure assumptions. We find that the performance of ensemble mean closures is highly dependent on the spatiotemporal structure of the forcing. Under slowly varying forcing, approximate closures reproduce the mean evolution reasonably well; under rapidly varying, near-zero-mean forcing, the simplest ensemble-mean closures fail, even at the level of basin-averaged total energy and enstrophy. In both regimes, the ensemble-mean response is not simply the accumulated imprint of the applied forcing, but instead appears as a continuing, non-equilibrated dialogue between the mean and eddy fields.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"88 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147393260","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 : 2026-03-11DOI: 10.3389/fmars.2026.1773304
Eric Yong Joong Lee, Juhyun Park, MooYoung Choi, Junghwan Choi
Background Japan's ongoing discharge of treated radioactive wastewater from the Fukushima Daiichi Nuclear Power Plant, approved by the IAEA as consistent with international safety standards, has generated significant scientific and legal controversy. The safety justification relies on assumptions regarding TEPCO's ALPS treatment system effectiveness, monitoring reliability, data transparency, and minimal risks to marine ecosystems and human health. Methods This paper employs an interdisciplinary approach integrating marine science and international law. We categorize Japan and TEPCO's scientific justifications into four core claims and highlight the scientific uncertainties that weaken the strength of such claims. As part of this, we apply fundamental dose-calculation methods to estimate organ-specific absorbed and effective doses for key radionuclides (tritium, cesium-137, strontium-90) and their potential health impacts. We then systematically map identified scientific uncertainties to corresponding structural weaknesses in international legal accountability mechanisms. Results Our analysis reveals substantial uncertainties undermining Japan's safety claims. These empirical gaps systematically expose structural failures in international governance: absence of technology verification standards, lack of binding testing protocols, inadequacies in instantaneous concentration-based compliance frameworks, outdated safety standards, national control preventing independent verification, and weaknesses in the IAEA institutional architecture. Conclusions The systematic pattern where scientific uncertainties map onto legal gaps reflects a fundamental mismatch between current frameworks, which are designed for routine operations, and the unprecedented circumstances of the multi-decade discharges from Fukushima. We provide concrete scientific, legal, and policy recommendations targeting each identified vulnerability to prevent Fukushima from establishing a dangerous precedent for inadequately regulated ocean disposal.
日本正在进行的福岛第一核电站（Fukushima Daiichi Nuclear Power Plant）处理过的放射性废水的排放，已被国际原子能机构（IAEA）批准为符合国际安全标准，这在科学和法律上引发了重大争议。安全理由依赖于关于TEPCO的ALPS处理系统有效性、监测可靠性、数据透明度以及对海洋生态系统和人类健康的最小风险的假设。方法采用跨学科研究方法，将海洋科学与国际法相结合。我们将日本和东京电力公司的科学理由分为四个核心主张，并强调了削弱这些主张力量的科学不确定性。作为这项工作的一部分，我们应用基本剂量计算方法来估计关键放射性核素（氚、铯-137、锶-90）的器官特异性吸收剂量和有效剂量及其潜在的健康影响。然后，我们系统地将已确定的科学不确定性映射到国际法律问责机制中相应的结构性弱点。结果：我们的分析揭示了大量的不确定性，这些不确定性削弱了日本的安全声明。这些经验上的差距系统地暴露了国际治理中的结构性缺陷：缺乏技术核查标准、缺乏具有约束力的测试协议、基于即时集中的合规框架的不足、过时的安全标准、阻碍独立核查的国家控制以及原子能机构机构架构中的弱点。科学上的不确定性映射到法律漏洞的系统模式反映了当前为日常操作设计的框架与福岛数十年排放的前所未有的情况之间的根本不匹配。我们针对每一个已确定的脆弱性提供具体的科学、法律和政策建议，以防止福岛核电站为监管不力的海洋处置建立一个危险的先例。
{"title":"Resisting oblivion: scientific criticism and legal possibilities concerning the discharges of radioactive water from Fukushima","authors":"Eric Yong Joong Lee, Juhyun Park, MooYoung Choi, Junghwan Choi","doi":"10.3389/fmars.2026.1773304","DOIUrl":"https://doi.org/10.3389/fmars.2026.1773304","url":null,"abstract":"Background Japan's ongoing discharge of treated radioactive wastewater from the Fukushima Daiichi Nuclear Power Plant, approved by the IAEA as consistent with international safety standards, has generated significant scientific and legal controversy. The safety justification relies on assumptions regarding TEPCO's ALPS treatment system effectiveness, monitoring reliability, data transparency, and minimal risks to marine ecosystems and human health. Methods This paper employs an interdisciplinary approach integrating marine science and international law. We categorize Japan and TEPCO's scientific justifications into four core claims and highlight the scientific uncertainties that weaken the strength of such claims. As part of this, we apply fundamental dose-calculation methods to estimate organ-specific absorbed and effective doses for key radionuclides (tritium, cesium-137, strontium-90) and their potential health impacts. We then systematically map identified scientific uncertainties to corresponding structural weaknesses in international legal accountability mechanisms. Results Our analysis reveals substantial uncertainties undermining Japan's safety claims. These empirical gaps systematically expose structural failures in international governance: absence of technology verification standards, lack of binding testing protocols, inadequacies in instantaneous concentration-based compliance frameworks, outdated safety standards, national control preventing independent verification, and weaknesses in the IAEA institutional architecture. Conclusions The systematic pattern where scientific uncertainties map onto legal gaps reflects a fundamental mismatch between current frameworks, which are designed for routine operations, and the unprecedented circumstances of the multi-decade discharges from Fukushima. We provide concrete scientific, legal, and policy recommendations targeting each identified vulnerability to prevent Fukushima from establishing a dangerous precedent for inadequately regulated ocean disposal.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"415 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147393261","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 : 2026-03-10DOI: 10.3389/fmars.2026.1762170
Muhammad Rashid, Junfeng Wang, Faheem Ahmed, Naeem Ahmed, Syed Agha Hassnain Mohsan, Eatedal Alabdulkreem, Samih M. Mostafa
Introduction Underwater target detection plays a crucial role in marine environmental monitoring and ocean exploration. However, accurate detection remains challenging due to low illumination, blurred small objects, and complex background interference. Although convolutional neural network-based detectors have improved detection performance, many existing approaches are computationally expensive, limiting their deployment on resource-constrained underwater platforms. Methods To address these challenges, we propose YOLOv8n-PFA, a lightweight and high-precision underwater object detection framework. The proposed method introduces a novel Parallel Fusion Attention (PFA) module that models channel and spatial attention in parallel using residual connections to enhance discriminative features while suppressing background noise. The Wise Intersection over Union (WIoUv3) loss is incorporated to stabilize training and improve localization accuracy. Additionally, depth-wise convolutions (DWConv) are strategically applied to reduce model parameters and computational complexity. To further validate generalization capability, the PFA module is also integrated into YOLOv11n. Results Experimental results show that YOLOv8n-PFA achieves 84.2% mean Average Precision (mAP) on the URPC2020 dataset with 2.68 M parameters and 7.7 GFLOPs, and 84.8% mAP on the RUOD dataset with 2.98 M parameters and 7.9 GFLOPs. When integrated into YOLOv11n, the model achieves 84.7% mAP on URPC2020 and 85.3% on RUOD with only 2.76 M parameters and 6.5 GFLOPs. Across both datasets, the proposed approach improves mAP by 2.8-4.1% over baseline models while maintaining a lightweight architecture. Discussion The results demonstrate that the proposed framework provides an effective and computationally efficient solution for real-time underwater target detection in challenging marine environments. The consistent performance gains across different YOLO generations further confirm the scalability and robustness of the proposed PFA module.
{"title":"YOLOv8n-PFA: a parallel fusion attention network for enhanced target detection in challenging environments","authors":"Muhammad Rashid, Junfeng Wang, Faheem Ahmed, Naeem Ahmed, Syed Agha Hassnain Mohsan, Eatedal Alabdulkreem, Samih M. Mostafa","doi":"10.3389/fmars.2026.1762170","DOIUrl":"https://doi.org/10.3389/fmars.2026.1762170","url":null,"abstract":"Introduction Underwater target detection plays a crucial role in marine environmental monitoring and ocean exploration. However, accurate detection remains challenging due to low illumination, blurred small objects, and complex background interference. Although convolutional neural network-based detectors have improved detection performance, many existing approaches are computationally expensive, limiting their deployment on resource-constrained underwater platforms. Methods To address these challenges, we propose YOLOv8n-PFA, a lightweight and high-precision underwater object detection framework. The proposed method introduces a novel Parallel Fusion Attention (PFA) module that models channel and spatial attention in parallel using residual connections to enhance discriminative features while suppressing background noise. The Wise Intersection over Union (WIoUv3) loss is incorporated to stabilize training and improve localization accuracy. Additionally, depth-wise convolutions (DWConv) are strategically applied to reduce model parameters and computational complexity. To further validate generalization capability, the PFA module is also integrated into YOLOv11n. Results Experimental results show that YOLOv8n-PFA achieves 84.2% mean Average Precision (mAP) on the URPC2020 dataset with 2.68 M parameters and 7.7 GFLOPs, and 84.8% mAP on the RUOD dataset with 2.98 M parameters and 7.9 GFLOPs. When integrated into YOLOv11n, the model achieves 84.7% mAP on URPC2020 and 85.3% on RUOD with only 2.76 M parameters and 6.5 GFLOPs. Across both datasets, the proposed approach improves mAP by 2.8-4.1% over baseline models while maintaining a lightweight architecture. Discussion The results demonstrate that the proposed framework provides an effective and computationally efficient solution for real-time underwater target detection in challenging marine environments. The consistent performance gains across different YOLO generations further confirm the scalability and robustness of the proposed PFA module.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"67 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147383678","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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