Pub Date : 2026-01-05DOI: 10.3389/fmars.2025.1705054
Yingbang Huang, Yu Tang, Tianyu Zhang, LiLi Zhou
Introduction Fishing vessel safety is critical for the sustainable development of fisheries in Guangdong Province, China. Methods This study systematically assessed the safety status of fishing vessels based on data from 687 accidents between 2019 and 2023, using a multi-method framework that combines the International Maritime Organization (IMO) taxonomy, Kernel Density Estimation (KDE), grid-based accident location statistics, and Exploratory Data Analysis (EDA). Results Key findings reveal that "Collision" accidents accounted for the highest proportion (47.16%), representing the primary accident type; while "Mechanical Damage/Failure" incidents occurred less frequently (7.28%), 98% resulted in severe casualties, highlighting their high hazard potential. Significant differences in vessel length, tonnage, and power output were observed among fishing vessels of different materials (steel vs. fiberglass). Spatial analysis indicates that the coastal areas from Yangjiang and Maoming to Zhanjiang, along with the Pearl River Estuary, constitute extremely high-risk zones. Accident distribution exhibits pronounced spatiotemporal clustering, such as a peak in August and the highest risk occurring at 9:00 AM. Discussion Based on these findings, the study proposes targeted measures including strengthening technical prevention and precise supervision, establishing a dynamic risk-tiered control mechanism, and constructing a data-driven long-term management system. This study not only deepens systematic understanding of fishing vessel safety risks in Guangdong Province but also provides replicable empirical evidence and decision support for relevant fisheries safety authorities.
{"title":"A multi-method comprehensive analysis of the taxonomy-based risk assessment of fishing vessel safety in Guangdong Province","authors":"Yingbang Huang, Yu Tang, Tianyu Zhang, LiLi Zhou","doi":"10.3389/fmars.2025.1705054","DOIUrl":"https://doi.org/10.3389/fmars.2025.1705054","url":null,"abstract":"Introduction Fishing vessel safety is critical for the sustainable development of fisheries in Guangdong Province, China. Methods This study systematically assessed the safety status of fishing vessels based on data from 687 accidents between 2019 and 2023, using a multi-method framework that combines the International Maritime Organization (IMO) taxonomy, Kernel Density Estimation (KDE), grid-based accident location statistics, and Exploratory Data Analysis (EDA). Results Key findings reveal that \"Collision\" accidents accounted for the highest proportion (47.16%), representing the primary accident type; while \"Mechanical Damage/Failure\" incidents occurred less frequently (7.28%), 98% resulted in severe casualties, highlighting their high hazard potential. Significant differences in vessel length, tonnage, and power output were observed among fishing vessels of different materials (steel vs. fiberglass). Spatial analysis indicates that the coastal areas from Yangjiang and Maoming to Zhanjiang, along with the Pearl River Estuary, constitute extremely high-risk zones. Accident distribution exhibits pronounced spatiotemporal clustering, such as a peak in August and the highest risk occurring at 9:00 AM. Discussion Based on these findings, the study proposes targeted measures including strengthening technical prevention and precise supervision, establishing a dynamic risk-tiered control mechanism, and constructing a data-driven long-term management system. This study not only deepens systematic understanding of fishing vessel safety risks in Guangdong Province but also provides replicable empirical evidence and decision support for relevant fisheries safety authorities.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"25 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145897316","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 : 2026-01-05DOI: 10.3389/fmars.2025.1681544
Graeme Guy, Jessica A. Sameoto, Ryan R. E. Stanley, Karsten N. Economou, Wendy C. Gentleman
Evidence-based decision making as part of marine spatial planning (MSP) requires an understanding of marine ecosystem structure and functioning, including associated spatial-temporal variability. Community spatial structure, such as that derived from larval transport dynamics, should be considered in decision making because it can govern system stability and resilience to perturbation. We utilize a novel network-theoretic approach for evaluating connectivity and identifying statistically persistent connectivity cores in community structure for use as a decision support tool for MSP. Using the Atlantic Sea Scallop as a case study, we simulated scallop larval dispersal for spring and fall spawning periods from 2018 to 2022 using the Finite‐Volume Coastal Ocean Model (FVCOM) particle‐tracking module with explicit temperature dependent development and vertical‐swimming behavior parameterizations. We adapted a novel Recursive Significance Clustering (RSC) scheme to characterize and contrast statistically significant connectivity core structure from dispersal networks at both seasonal and 5-year timescales. Statistically persistent cores emerged within the Bay of Fundy, on Browns Bank, Georges Bank, and Sable Bank at both time scales. Regions of high spatial and temporal variability in community structure included the Great South Channel, Western Gulf of Maine, and in regions bordering communities. We also characterize potential source-sink larval dynamics using degree-based connectivity metrics, which revealed the Bay of Fundy to Browns Bank and the Great South Channel as potential sources and the Northern Gulf of Maine as a potential sink. Our results characterize variable scallop community structure and provide valuable information for MSP decisions surrounding fisheries management and offshore energy development. This framework can be applied to other species and regions for local MSP objectives.
{"title":"A network-theoretic approach for evaluating connectivity and statistically persistent community structure for marine spatial planning","authors":"Graeme Guy, Jessica A. Sameoto, Ryan R. E. Stanley, Karsten N. Economou, Wendy C. Gentleman","doi":"10.3389/fmars.2025.1681544","DOIUrl":"https://doi.org/10.3389/fmars.2025.1681544","url":null,"abstract":"Evidence-based decision making as part of marine spatial planning (MSP) requires an understanding of marine ecosystem structure and functioning, including associated spatial-temporal variability. Community spatial structure, such as that derived from larval transport dynamics, should be considered in decision making because it can govern system stability and resilience to perturbation. We utilize a novel network-theoretic approach for evaluating connectivity and identifying statistically persistent connectivity cores in community structure for use as a decision support tool for MSP. Using the Atlantic Sea Scallop as a case study, we simulated scallop larval dispersal for spring and fall spawning periods from 2018 to 2022 using the Finite‐Volume Coastal Ocean Model (FVCOM) particle‐tracking module with explicit temperature dependent development and vertical‐swimming behavior parameterizations. We adapted a novel Recursive Significance Clustering (RSC) scheme to characterize and contrast statistically significant connectivity core structure from dispersal networks at both seasonal and 5-year timescales. Statistically persistent cores emerged within the Bay of Fundy, on Browns Bank, Georges Bank, and Sable Bank at both time scales. Regions of high spatial and temporal variability in community structure included the Great South Channel, Western Gulf of Maine, and in regions bordering communities. We also characterize potential source-sink larval dynamics using degree-based connectivity metrics, which revealed the Bay of Fundy to Browns Bank and the Great South Channel as potential sources and the Northern Gulf of Maine as a potential sink. Our results characterize variable scallop community structure and provide valuable information for MSP decisions surrounding fisheries management and offshore energy development. This framework can be applied to other species and regions for local MSP objectives.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"18 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145897318","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 : 2026-01-05DOI: 10.3389/fmars.2025.1720926
Bai Dan, Wang Tao
Marine plastic pollution in Northeast Asian seas exhibits significant transboundary characteristics, yet existing governance regimes—particularly the Northwest Pacific Action Plan (NOWPAP)—lack judicial enforcement mechanisms to hold polluters accountable. The diffuse nature of pollution renders traditional tort law’s causation requirements inoperative. Objective: This study constructs a trilateral judicial cooperation framework among China, Japan, and Korea to address the accountability vacuum in transboundary marine plastic pollution cases. Employing comparative legal analysis of international environmental tort precedents ( Trail Smelter , Pulp Mills cases) and institutional design methodology, this research adapts the U.S. market-share liability doctrine to transboundary pollution contexts and proposes a three-tier cooperation mechanism. The proposed framework comprises: (1) evidence collection and sharing protocols utilizing chemical fingerprinting and oceanographic drift modeling; (2) jurisdictional coordination rules to prevent forum shopping and parallel litigation; and (3) mutual recognition and enforcement mechanisms for environmental judgments. The framework leverages the existing Tripartite Environment Ministers Meeting (TEMM) platform while transforming it into an enforceable judicial architecture. By reconstructing causation requirements through pollution contribution ratios and establishing systematic judicial cooperation, this framework provides a replicable model for regional ocean governance. It directly contributes to ongoing International Plastics Treaty (INC) negotiations on transboundary liability provisions and demonstrates how soft law regimes can evolve into hard enforcement mechanisms. Yet the framework’s practical realization ultimately depends on participating states’ political will, their readiness to accept reciprocal enforcement obligations, and the gradual evolution of existing regional arrangements. Accordingly, the analysis treats the proposed architecture as a normative blueprint and feasibility exploration rather than an immediately operational regime. Given uneven doctrinal development and limited publicly accessible case law in Japan and Korea, the comparative assessment is necessarily selective, highlighting areas where further empirical and diplomatic work will be required.
{"title":"Bridging the accountability gap: designing a China-Japan-Korea judicial cooperation framework for transboundary marine plastic pollution","authors":"Bai Dan, Wang Tao","doi":"10.3389/fmars.2025.1720926","DOIUrl":"https://doi.org/10.3389/fmars.2025.1720926","url":null,"abstract":"Marine plastic pollution in Northeast Asian seas exhibits significant transboundary characteristics, yet existing governance regimes—particularly the Northwest Pacific Action Plan (NOWPAP)—lack judicial enforcement mechanisms to hold polluters accountable. The diffuse nature of pollution renders traditional tort law’s causation requirements inoperative. Objective: This study constructs a trilateral judicial cooperation framework among China, Japan, and Korea to address the accountability vacuum in transboundary marine plastic pollution cases. Employing comparative legal analysis of international environmental tort precedents ( <jats:italic>Trail Smelter</jats:italic> , <jats:italic>Pulp Mills</jats:italic> cases) and institutional design methodology, this research adapts the U.S. market-share liability doctrine to transboundary pollution contexts and proposes a three-tier cooperation mechanism. The proposed framework comprises: (1) evidence collection and sharing protocols utilizing chemical fingerprinting and oceanographic drift modeling; (2) jurisdictional coordination rules to prevent forum shopping and parallel litigation; and (3) mutual recognition and enforcement mechanisms for environmental judgments. The framework leverages the existing Tripartite Environment Ministers Meeting (TEMM) platform while transforming it into an enforceable judicial architecture. By reconstructing causation requirements through pollution contribution ratios and establishing systematic judicial cooperation, this framework provides a replicable model for regional ocean governance. It directly contributes to ongoing International Plastics Treaty (INC) negotiations on transboundary liability provisions and demonstrates how soft law regimes can evolve into hard enforcement mechanisms. Yet the framework’s practical realization ultimately depends on participating states’ political will, their readiness to accept reciprocal enforcement obligations, and the gradual evolution of existing regional arrangements. Accordingly, the analysis treats the proposed architecture as a normative blueprint and feasibility exploration rather than an immediately operational regime. Given uneven doctrinal development and limited publicly accessible case law in Japan and Korea, the comparative assessment is necessarily selective, highlighting areas where further empirical and diplomatic work will be required.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"1 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145897315","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 zones are vital to economies and societies, supporting diverse ecosystems, human settlements, and critical infrastructure. However, these areas face increasing threats from storm surges and coastal flooding. Traditional engineering solutions like seawalls and groins often disrupt natural processes and encourage unsustainable development, leading to a growing interest in Nature-based Solutions (NbS) such as wetlands and coastal vegetation. An assessment of the protective function of these NbS requires improved understanding of their influence on coastal processes, including wave runup. Despite the availability of many empirical equations for predicting wave runup on bare beaches, comparable equations for vegetated beaches remain largely undeveloped. This study develops empirical equations for predicting short wave runup on vegetated beaches through integrated numerical modeling and expression programming techniques. The research investigates four key parameters: significant wave height ( H s ), peak wave period ( T p ), beach slope ( S ) and vegetation density ( N v ) across two vegetation types: rigid and flexible. Orthogonal sampling generates 768 simulation scenarios per vegetation type. The XBeach Non-Hydrostatic is then utilized to simulate wave runup under the generated wave and vegetation scenarios. To develop runup equations, dimensional analysis transforms parameters into three dimensionless variables: Iribarren number, wave steepness, and vegetation characteristics (number of stems). The Artificial Bee Colony Expression Programming ( ABCEP ) algorithm derives vegetation-specific runup empirical equations from the resulting dataset. Results demonstrate acceptable predictive performance with R² values exceeding 0.94 for both vegetation types. Validation against independent numerical data confirms superior performance compared to widely-used wave runup formulations established for non-vegetated beaches. The empirical equations developed in this research provide coastal engineers and practitioners with tools explicitly incorporating vegetation density for short wave runup prediction.
{"title":"Wave runup on vegetated beaches: data-driven empirical equations for rigid and flexible vegetation types","authors":"Erfan Andalibi, Erfan Amini, Seyed Taghi Omid Naeeni, Ali Arjmand, Reza Marsooli","doi":"10.3389/fmars.2025.1711843","DOIUrl":"https://doi.org/10.3389/fmars.2025.1711843","url":null,"abstract":"Coastal zones are vital to economies and societies, supporting diverse ecosystems, human settlements, and critical infrastructure. However, these areas face increasing threats from storm surges and coastal flooding. Traditional engineering solutions like seawalls and groins often disrupt natural processes and encourage unsustainable development, leading to a growing interest in Nature-based Solutions (NbS) such as wetlands and coastal vegetation. An assessment of the protective function of these NbS requires improved understanding of their influence on coastal processes, including wave runup. Despite the availability of many empirical equations for predicting wave runup on bare beaches, comparable equations for vegetated beaches remain largely undeveloped. This study develops empirical equations for predicting short wave runup on vegetated beaches through integrated numerical modeling and expression programming techniques. The research investigates four key parameters: significant wave height ( <jats:italic> H <jats:sub>s</jats:sub> </jats:italic> ), peak wave period ( <jats:italic> T <jats:sub>p</jats:sub> </jats:italic> ), beach slope ( <jats:italic>S</jats:italic> ) and vegetation density ( <jats:italic> N <jats:sub>v</jats:sub> </jats:italic> ) across two vegetation types: rigid and flexible. Orthogonal sampling generates 768 simulation scenarios per vegetation type. The XBeach Non-Hydrostatic is then utilized to simulate wave runup under the generated wave and vegetation scenarios. To develop runup equations, dimensional analysis transforms parameters into three dimensionless variables: Iribarren number, wave steepness, and vegetation characteristics (number of stems). The Artificial Bee Colony Expression Programming ( <jats:italic>ABCEP</jats:italic> ) algorithm derives vegetation-specific runup empirical equations from the resulting dataset. Results demonstrate acceptable predictive performance with R² values exceeding 0.94 for both vegetation types. Validation against independent numerical data confirms superior performance compared to widely-used wave runup formulations established for non-vegetated beaches. The empirical equations developed in this research provide coastal engineers and practitioners with tools explicitly incorporating vegetation density for short wave runup prediction.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"39 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145897317","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}
Underwater image degradation resulting from light absorption and scattering in water significantly affects the visual perception of autonomous underwater vehicles (AUVs), subsea infrastructure inspections, and marine environmental monitoring. We propose a lightweight enhancement algorithm (UIVE) for underwater images and videos through a lightweight design of residual block replacement BN layer. The innovation of this study is reflected in the dynamic combination of downsampling features and upsampling process through multi-scale jump connection, which effectively retains multi-scale detail information. Replacing the batch normalization (BN) layer strategy with residual blocks effectively reduces computational complexity while maintaining model performance and significantly enhances the effectiveness of feature migration. The adaptive brightness correction module is introduced to compensate for the problem of image brightness reduction after the nonlinear mapping model. Experiments show that UIVE achieves a PSNR value of 18.57 dB and a SSIM value of 0.91 on the UIEB dataset, respectively, and especially demonstrates an obvious advantage in removing bias color. In terms of real-time processing, UIVE achieves a frame rate of 36.23 frames per second (FPS) with a video resolution of 640×480 pixels and can be deployed on embedded systems in AUV or ROV. Experimental results demonstrate that UIVE excels in color correction and detail reproduction, making it particularly well-suited for applications in underwater environments within marine engineering.
{"title":"A lightweight underwater image and video enhancement method based on multi-scale feature fusion","authors":"Gaosheng Luo, Haiyang Li, Huanhuan Wang, Hengshou Sui, Xuewen Zhang, Rongjun Zhang, Bocheng Chen, Zhe Jiang","doi":"10.3389/fmars.2025.1725829","DOIUrl":"https://doi.org/10.3389/fmars.2025.1725829","url":null,"abstract":"Underwater image degradation resulting from light absorption and scattering in water significantly affects the visual perception of autonomous underwater vehicles (AUVs), subsea infrastructure inspections, and marine environmental monitoring. We propose a lightweight enhancement algorithm (UIVE) for underwater images and videos through a lightweight design of residual block replacement BN layer. The innovation of this study is reflected in the dynamic combination of downsampling features and upsampling process through multi-scale jump connection, which effectively retains multi-scale detail information. Replacing the batch normalization (BN) layer strategy with residual blocks effectively reduces computational complexity while maintaining model performance and significantly enhances the effectiveness of feature migration. The adaptive brightness correction module is introduced to compensate for the problem of image brightness reduction after the nonlinear mapping model. Experiments show that UIVE achieves a PSNR value of 18.57 dB and a SSIM value of 0.91 on the UIEB dataset, respectively, and especially demonstrates an obvious advantage in removing bias color. In terms of real-time processing, UIVE achieves a frame rate of 36.23 frames per second (FPS) with a video resolution of 640×480 pixels and can be deployed on embedded systems in AUV or ROV. Experimental results demonstrate that UIVE excels in color correction and detail reproduction, making it particularly well-suited for applications in underwater environments within marine engineering.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"38 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145897319","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 : 2026-01-05DOI: 10.3389/fmars.2025.1715156
DongPing Pu, Wei Yan, Guanghui Yuan
Government environmental subsidies and port-shipping enterprise collaboration are common ways to promote carbon emission reduction. To analyze the long-term effects of collaboration and subsidies, game models based on decentralized and centralized decision-making are constructed: Stackelberg games led by either the port or the shipping enterprise, vertical integration, and Nash bargaining game. Then, by comprehensively analyzing government subsidy coefficients, corporate investment costs, and shippers’ low-carbon preferences, the collaborative model that maximizes both emission reduction effectiveness and industry profits is identified. On this basis, the game reaction function and system dynamics are combined to reflect the nonlinear complex feedback, in order to accurately analyze the port-shipping green transformation under dynamic effects of decision delay, technology update and subsidy decline. The findings reveal that the centralized decision-making model yields higher shipping decarbonization benefits than the decentralized model. Excessive subsidies may discourage independent innovation. Therefore, subsidies only play a short-term incentive role, while collaboration can promote the sustainable development of the port and shipping industry.
{"title":"Do collaboration and subsidies sustainably promote port-shipping emission reduction? An analysis of multi-games and system dynamics","authors":"DongPing Pu, Wei Yan, Guanghui Yuan","doi":"10.3389/fmars.2025.1715156","DOIUrl":"https://doi.org/10.3389/fmars.2025.1715156","url":null,"abstract":"Government environmental subsidies and port-shipping enterprise collaboration are common ways to promote carbon emission reduction. To analyze the long-term effects of collaboration and subsidies, game models based on decentralized and centralized decision-making are constructed: Stackelberg games led by either the port or the shipping enterprise, vertical integration, and Nash bargaining game. Then, by comprehensively analyzing government subsidy coefficients, corporate investment costs, and shippers’ low-carbon preferences, the collaborative model that maximizes both emission reduction effectiveness and industry profits is identified. On this basis, the game reaction function and system dynamics are combined to reflect the nonlinear complex feedback, in order to accurately analyze the port-shipping green transformation under dynamic effects of decision delay, technology update and subsidy decline. The findings reveal that the centralized decision-making model yields higher shipping decarbonization benefits than the decentralized model. Excessive subsidies may discourage independent innovation. Therefore, subsidies only play a short-term incentive role, while collaboration can promote the sustainable development of the port and shipping industry.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"39 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145897320","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 : 2026-01-02DOI: 10.3389/fmars.2025.1704819
Deyselana Lima da Costa, Bruno José Corecha Fernandes Eiras, Jean Danilo da Silva Pereira, Adriele Carolina Raiol Rodrigues, Hayanna Lucy Barbosa Barros, Glauber David Almeida Palheta, Nuno Filipe Alves Correia de Melo, Maria de Lourdes Souza Santos, João Felipe Nogueira Matias, Fabio Carneiro Sterzelecki
Introduction The Blue Amazon represents an extensive coastal zone with high biodiversity and wide salinity variation, which poses challenges for marine fish farming, particularly regarding the efficiency of biofilters in recirculating aquaculture systems (RAS). In this context, açaí seeds ( Euterpe oleracea ), previously evaluated in freshwater, emerge as a promising alternative for use as filter media under different salinity conditions. The objective of this study was to evaluate the potential of açaí seeds as substrate in RAS biofilters, analyzing their acute and chronic impact on the physicochemical parameters of water and the removal of ammonia, nitrite and nitrate over 28 days. Methods The experiment was conducted in six independent systems (three aquaria each), subjected to salinities of 0, 7, 14, 21, 28 and 35‰. After Acute (0, 20, 40, 60,80,100 and 120 minutes) and chronic (2,3,4,14,21 and 28 days) salinity change, water samples were collected to measure physicochemical quality and to assess nitrification efficiency and nitrogen compound removal. Results Higher oxygen consumption and ammonia clearance were observed at 0, 7 and 14‰ after 120 minutes of salinity change, while nitrate accumulation was significantly higher in freshwater. In long term, after 28 days, ammonia clearance was significantly lower at 35‰, though nitrate accumulation was not affected by salinity. The highest ammonia removal rates were recorded in the 0‰ and 7‰ treatments. Discussion The results demonstrate that açaí seeds are capable of removing ammonia after a few minutes and can sustain the growth of nitrifying bacteria under different salinity levels, although more efficiently in low salinity waters (seven times).
{"title":"Acute and chronic effects of salinity on nitrification in a recirculating aquaculture system with açaí seeds (Euterpe oleracea) as biological media","authors":"Deyselana Lima da Costa, Bruno José Corecha Fernandes Eiras, Jean Danilo da Silva Pereira, Adriele Carolina Raiol Rodrigues, Hayanna Lucy Barbosa Barros, Glauber David Almeida Palheta, Nuno Filipe Alves Correia de Melo, Maria de Lourdes Souza Santos, João Felipe Nogueira Matias, Fabio Carneiro Sterzelecki","doi":"10.3389/fmars.2025.1704819","DOIUrl":"https://doi.org/10.3389/fmars.2025.1704819","url":null,"abstract":"Introduction The Blue Amazon represents an extensive coastal zone with high biodiversity and wide salinity variation, which poses challenges for marine fish farming, particularly regarding the efficiency of biofilters in recirculating aquaculture systems (RAS). In this context, açaí seeds ( <jats:italic>Euterpe oleracea</jats:italic> ), previously evaluated in freshwater, emerge as a promising alternative for use as filter media under different salinity conditions. The objective of this study was to evaluate the potential of açaí seeds as substrate in RAS biofilters, analyzing their acute and chronic impact on the physicochemical parameters of water and the removal of ammonia, nitrite and nitrate over 28 days. Methods The experiment was conducted in six independent systems (three aquaria each), subjected to salinities of 0, 7, 14, 21, 28 and 35‰. After Acute (0, 20, 40, 60,80,100 and 120 minutes) and chronic (2,3,4,14,21 and 28 days) salinity change, water samples were collected to measure physicochemical quality and to assess nitrification efficiency and nitrogen compound removal. Results Higher oxygen consumption and ammonia clearance were observed at 0, 7 and 14‰ after 120 minutes of salinity change, while nitrate accumulation was significantly higher in freshwater. In long term, after 28 days, ammonia clearance was significantly lower at 35‰, though nitrate accumulation was not affected by salinity. The highest ammonia removal rates were recorded in the 0‰ and 7‰ treatments. Discussion The results demonstrate that açaí seeds are capable of removing ammonia after a few minutes and can sustain the growth of nitrifying bacteria under different salinity levels, although more efficiently in low salinity waters (seven times).","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"8 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145894965","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 : 2026-01-02DOI: 10.3389/fmars.2025.1671057
Suyong Zhang, Xiyan Song
The IMO has taken proactive steps to promote carbon emission reductions in the maritime industry as the severity of global warming increases. As a result, several nations and regions have made developing shore electrical technology a top priority. Through the establishment of a four-party evolutionary game model comprising the government, ports, shipping corporations, and power companies, this article seeks to explore the promotion of shore electricity for sustainable port development. The model’s goal is to investigate how each stakeholder makes decisions and interacts with one another in the process of promoting shore energy. We find multiple stable equilibrium points and their corresponding criteria by doing a stability analysis. We also conduct a sensitivity analysis to evaluate the effects on each participant of the magnitude of government incentives and related expenses. This investigation leads us to three important conclusions: First, all stakeholders’ decision-making processes are greatly influenced by government policies. Second, economic factors limit the adoption of shore electricity technology and have a direct impact on the strategic decisions made by all parties. Finally, incentives and cooperation among the stakeholders are shown to be successful strategies for attaining low-carbon growth in the shipping industry. Ports and shipping businesses are more willing to use shore electrical technology when government support is available, and power corporations are more willing to make investments.
{"title":"Synergies between government, ports, shipping companies, and power companies","authors":"Suyong Zhang, Xiyan Song","doi":"10.3389/fmars.2025.1671057","DOIUrl":"https://doi.org/10.3389/fmars.2025.1671057","url":null,"abstract":"The IMO has taken proactive steps to promote carbon emission reductions in the maritime industry as the severity of global warming increases. As a result, several nations and regions have made developing shore electrical technology a top priority. Through the establishment of a four-party evolutionary game model comprising the government, ports, shipping corporations, and power companies, this article seeks to explore the promotion of shore electricity for sustainable port development. The model’s goal is to investigate how each stakeholder makes decisions and interacts with one another in the process of promoting shore energy. We find multiple stable equilibrium points and their corresponding criteria by doing a stability analysis. We also conduct a sensitivity analysis to evaluate the effects on each participant of the magnitude of government incentives and related expenses. This investigation leads us to three important conclusions: First, all stakeholders’ decision-making processes are greatly influenced by government policies. Second, economic factors limit the adoption of shore electricity technology and have a direct impact on the strategic decisions made by all parties. Finally, incentives and cooperation among the stakeholders are shown to be successful strategies for attaining low-carbon growth in the shipping industry. Ports and shipping businesses are more willing to use shore electrical technology when government support is available, and power corporations are more willing to make investments.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"1 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145894967","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 : 2026-01-02DOI: 10.3389/fmars.2025.1687272
Mochamad Iqbal Herwata Putra, Abdy W. Hasan, Hanggar Prasetio, Ismail Syakurachman, Elle Wibisono, Jimy Kalther, Asri Puji Lestari, Rian Prasetia, Yudi Herdiana, Achmad Sahri, Sekar M.C. Herandarudewi, Budiati Prasetiamartati, Meizani Irmadhiany, Mattie Rodrigue, Juan Pablo Torres-Florez, Victor Nikijuluw
Cetaceans are highly mobile marine species that pose substantial research challenges due to their wide home ranges, migratory behavior, and low detectability across vast and remote oceanic regions. These realities, combined with the high costs of systematic surveys, have created significant gaps in understanding their spatial distribution, habitat use, and vulnerability to human-induced threats, which are critical for effective conservation management. This study presents the first dedicated aerial transect survey of cetacean assemblages off the western coast of Sumatra in the southeastern tropical Indian Ocean, a region previously understudied despite its recognized importance for marine biodiversity. Conducted between May and July 2024, the survey covered 15,043 km of aerial transects and recorded 77 sightings of 10 species, including the first aerial confirmations of killer whales and pygmy killer whales. With these additions, a total of 23 species has now been documented in the region, representing 68% of Indonesia’s known cetaceans. Our non-metric multidimensional scaling revealed seven distinct cetacean assemblage clusters strongly influenced by seafloor geomorphology and productivity gradients. High-density hotspots, dominated by spinner and striped dolphins, were found predominantly in non-protected areas, with 93% located outside existing or proposed MPAs. The overlap of cetacean habitats with intensive fishing activities and maritime traffic highlights potential risks for species such as killer whales, Omura’s whales, and sperm whales. These findings emphasize the need for targeted spatial protection, adaptive marine spatial planning, and species-specific mitigation measures to complement Indonesia’s 30×45 MPA expansion efforts. Given its exceptional biodiversity and the presence of threatened species such as sperm whales, western Sumatra is a strong candidate for designation as an important marine mammal area, consistent with its status as an ecologically or biologically significant marine area. This study establishes a critical ecological baseline, demonstrating the value of large-scale aerial surveys for informing evidence-based cetacean conservation in Indonesia’s offshore habitats.
{"title":"From the air to the ocean: revealing cetacean assemblages in the Southeastern Indian Ocean","authors":"Mochamad Iqbal Herwata Putra, Abdy W. Hasan, Hanggar Prasetio, Ismail Syakurachman, Elle Wibisono, Jimy Kalther, Asri Puji Lestari, Rian Prasetia, Yudi Herdiana, Achmad Sahri, Sekar M.C. Herandarudewi, Budiati Prasetiamartati, Meizani Irmadhiany, Mattie Rodrigue, Juan Pablo Torres-Florez, Victor Nikijuluw","doi":"10.3389/fmars.2025.1687272","DOIUrl":"https://doi.org/10.3389/fmars.2025.1687272","url":null,"abstract":"Cetaceans are highly mobile marine species that pose substantial research challenges due to their wide home ranges, migratory behavior, and low detectability across vast and remote oceanic regions. These realities, combined with the high costs of systematic surveys, have created significant gaps in understanding their spatial distribution, habitat use, and vulnerability to human-induced threats, which are critical for effective conservation management. This study presents the first dedicated aerial transect survey of cetacean assemblages off the western coast of Sumatra in the southeastern tropical Indian Ocean, a region previously understudied despite its recognized importance for marine biodiversity. Conducted between May and July 2024, the survey covered 15,043 km of aerial transects and recorded 77 sightings of 10 species, including the first aerial confirmations of killer whales and pygmy killer whales. With these additions, a total of 23 species has now been documented in the region, representing 68% of Indonesia’s known cetaceans. Our non-metric multidimensional scaling revealed seven distinct cetacean assemblage clusters strongly influenced by seafloor geomorphology and productivity gradients. High-density hotspots, dominated by spinner and striped dolphins, were found predominantly in non-protected areas, with 93% located outside existing or proposed MPAs. The overlap of cetacean habitats with intensive fishing activities and maritime traffic highlights potential risks for species such as killer whales, Omura’s whales, and sperm whales. These findings emphasize the need for targeted spatial protection, adaptive marine spatial planning, and species-specific mitigation measures to complement Indonesia’s 30×45 MPA expansion efforts. Given its exceptional biodiversity and the presence of threatened species such as sperm whales, western Sumatra is a strong candidate for designation as an important marine mammal area, consistent with its status as an ecologically or biologically significant marine area. This study establishes a critical ecological baseline, demonstrating the value of large-scale aerial surveys for informing evidence-based cetacean conservation in Indonesia’s offshore habitats.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"52 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145894964","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 : 2026-01-02DOI: 10.3389/fmars.2025.1718186
Elena Terzić, Ivica Vilibić
Being centrally located within the basin and exhibiting internally driven quasi-decadal variability, the Ionian Sea serves as a pivotal conduit for water-mass exchange between the Western and Eastern Mediterranean. Using 23 years (2001–2024) of Argo float profiles, we quantify recent thermohaline changes across six sub-basins of the Ionian. Throughout the study period, pronounced warming and salinification were observed, occurring at rates much higher than during the 20th century. Between 2022 and 2024, the southern and south-eastern Ionian intermediate waters (300–1200 m) warmed by 0.7–1.8°C and their salinity increased by 0.24–0.40, with maxima near 700–1000 m, reflecting an abrupt shift in water-mass properties. Concurrent ERA5 reanalysis reveals a pronounced negative winter heat-flux anomaly in 2021/2022, intensified wind stress, and elevated evaporation minus precipitation, all of which favored much pronounced convective mixing that transferred warm and saline waters to deeper layers. In parallel, anomalous intermediate-layer properties observed in the southern Adriatic during the same period suggest a broader, interconnected response of the Adriatic–Ionian system. Together, these processes may indicate a transition toward a warmer, more saline deep-Ionian state. If sustained, such a regime could weaken dense-water formation, alter the Mediterranean overturning circulation, and propagate anomalies westward into the Atlantic through the Gibraltar outflow.
{"title":"Twenty-first century thermohaline trends and abrupt shifts in the Ionian Sea","authors":"Elena Terzić, Ivica Vilibić","doi":"10.3389/fmars.2025.1718186","DOIUrl":"https://doi.org/10.3389/fmars.2025.1718186","url":null,"abstract":"Being centrally located within the basin and exhibiting internally driven quasi-decadal variability, the Ionian Sea serves as a pivotal conduit for water-mass exchange between the Western and Eastern Mediterranean. Using 23 years (2001–2024) of Argo float profiles, we quantify recent thermohaline changes across six sub-basins of the Ionian. Throughout the study period, pronounced warming and salinification were observed, occurring at rates much higher than during the 20th century. Between 2022 and 2024, the southern and south-eastern Ionian intermediate waters (300–1200 m) warmed by 0.7–1.8°C and their salinity increased by 0.24–0.40, with maxima near 700–1000 m, reflecting an abrupt shift in water-mass properties. Concurrent ERA5 reanalysis reveals a pronounced negative winter heat-flux anomaly in 2021/2022, intensified wind stress, and elevated evaporation minus precipitation, all of which favored much pronounced convective mixing that transferred warm and saline waters to deeper layers. In parallel, anomalous intermediate-layer properties observed in the southern Adriatic during the same period suggest a broader, interconnected response of the Adriatic–Ionian system. Together, these processes may indicate a transition toward a warmer, more saline deep-Ionian state. If sustained, such a regime could weaken dense-water formation, alter the Mediterranean overturning circulation, and propagate anomalies westward into the Atlantic through the Gibraltar outflow.","PeriodicalId":12479,"journal":{"name":"Frontiers in Marine Science","volume":"33 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145894966","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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