Pub Date : 2026-01-14DOI: 10.1016/j.rsma.2026.104779
Funda Üstün , Orçin Uygun , Levent Bat , Murat Dağtekin
This study examined the zooplankton composition, abundance, and biomass distribution, as well as their relationship with environmental variables at 17 stations between Sinop (Türkeli) and Samsun (Yakakent) in the Turkish Black Sea in June 2023. The mean zooplankton abundance and biomass were 705.85 ± 556.02 individuals (ind.)/m3 and 39.53 ± 37.33 mg/m3, respectively. The copepods were the most dominant taxa in terms of abundance and biomass, followed by Noctiluca scintillans. Coastal shallow stations were mainly characterised by higher abundances of Paracalanus parvus and Acartia clausi, whereas offshore deeper stations were associated with Pseudocalanus elongatus, Oithona similis and Parasagitta setosa. Zooplankton abundance and biomass exhibited marked spatial variability along the transect. The abundances of Pleopis polyphemoides and meroplankton groups were affected by temperature and salinity changes. These findings indicate that the zooplankton community structure exhibits spatial variation and is sensitive to environmental variables.
{"title":"Spatial patterns of zooplankton communities along the Sinop-Samsun transect","authors":"Funda Üstün , Orçin Uygun , Levent Bat , Murat Dağtekin","doi":"10.1016/j.rsma.2026.104779","DOIUrl":"10.1016/j.rsma.2026.104779","url":null,"abstract":"<div><div>This study examined the zooplankton composition, abundance, and biomass distribution, as well as their relationship with environmental variables at 17 stations between Sinop (Türkeli) and Samsun (Yakakent) in the Turkish Black Sea in June 2023. The mean zooplankton abundance and biomass were 705.85 ± 556.02 individuals (ind.)/m<sup>3</sup> and 39.53 ± 37.33 mg/m<sup>3</sup>, respectively. The copepods were the most dominant taxa in terms of abundance and biomass, followed by <em>Noctiluca scintillans</em>. Coastal shallow stations were mainly characterised by higher abundances of <em>Paracalanus parvus</em> and <em>Acartia clausi</em>, whereas offshore deeper stations were associated with <em>Pseudocalanus elongatus</em>, <em>Oithona similis</em> and <em>Parasagitta setosa</em>. Zooplankton abundance and biomass exhibited marked spatial variability along the transect. The abundances of <em>Pleopis polyphemoides</em> and meroplankton groups were affected by temperature and salinity changes. These findings indicate that the zooplankton community structure exhibits spatial variation and is sensitive to environmental variables.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"94 ","pages":"Article 104779"},"PeriodicalIF":2.4,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145981063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-13DOI: 10.1016/j.rsma.2026.104771
Sheng-Ping Wang , Wen-Qi Xu , Chih-Yu Lin , Toshihide Kitakado , Wei-Chuan Chiang
This study presents an integrated framework that combines age-structured stock assessment with management strategy evaluation (MSE) to support the sustainable management of dolphinfish (Coryphaena hippurus) in the Northwest Pacific Ocean. Using fishery-dependent data from Taiwan, including catch, standardised CPUE, and length composition, the assessment indicated that the stock is currently above SSBMSY and that fishing mortality remains below FMSY. To evaluate candidate management procedures (MPs) for setting future total allowable catches (TACs) under several uncertainties, a simulation-based MSE was implemented using a precautionary operating model with multiple stochastic replicates. Four different harvest control rules (HCRs) as main components of MPs were tested to assess trade-offs between biological safety and catch performance. Among these, a precautionary HCR demonstrated strong performance across conservation indicators, providing a practical example of how the framework can inform precautionary decision-making. Despite regional data constraints, the study demonstrates how MSE can be applied under data-limited conditions to evaluate strategies transparently and systematically. The modular design allows for future integration of environmental drivers, socio-economic considerations, and broader regional data inputs, offering a foundation for science-based, cooperative management of transboundary pelagic species in the region.
{"title":"Toward sustainable use of dolphinfish (Coryphaena hippurus) in the Northwest Pacific: A framework for stock assessment and management strategy evaluation","authors":"Sheng-Ping Wang , Wen-Qi Xu , Chih-Yu Lin , Toshihide Kitakado , Wei-Chuan Chiang","doi":"10.1016/j.rsma.2026.104771","DOIUrl":"10.1016/j.rsma.2026.104771","url":null,"abstract":"<div><div>This study presents an integrated framework that combines age-structured stock assessment with management strategy evaluation (MSE) to support the sustainable management of dolphinfish (<em>Coryphaena hippurus</em>) in the Northwest Pacific Ocean. Using fishery-dependent data from Taiwan, including catch, standardised CPUE, and length composition, the assessment indicated that the stock is currently above SSB<sub>MSY</sub> and that fishing mortality remains below F<sub>MSY</sub>. To evaluate candidate management procedures (MPs) for setting future total allowable catches (TACs) under several uncertainties, a simulation-based MSE was implemented using a precautionary operating model with multiple stochastic replicates. Four different harvest control rules (HCRs) as main components of MPs were tested to assess trade-offs between biological safety and catch performance. Among these, a precautionary HCR demonstrated strong performance across conservation indicators, providing a practical example of how the framework can inform precautionary decision-making. Despite regional data constraints, the study demonstrates how MSE can be applied under data-limited conditions to evaluate strategies transparently and systematically. The modular design allows for future integration of environmental drivers, socio-economic considerations, and broader regional data inputs, offering a foundation for science-based, cooperative management of transboundary pelagic species in the region.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"94 ","pages":"Article 104771"},"PeriodicalIF":2.4,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145980973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-12DOI: 10.1016/j.rsma.2026.104775
Zefu Liu , Aiping Huang , Bing Ma , Fei Dong , Xiaobo Liu
As an essential function of the Yinjiang-Jihuai Project, shipping in the Lake Chaohu area faces potential risks of oil spills. In response to the increasing threat of oil spill impacts on the lake, a comprehensive framework for assessing oil spill risks in inland lakes has been proposed. This framework integrates lake fluid dynamics (oil spill modeling), the Environmental Sensitivity Index (ESI). The framework was applied to Chaohu Lake in China, where oil slick migration paths were simulated at multiple oil spill accident points along the Chao shipping segment. A lake oil spill comprehensive risk index method was proposed to assess the severity of oil spill incidents and quantify the impact of single wind directions on oil slick migration. The results indicate that both wind direction and the flow field jointly influence the migration of the oil slick, with wind direction playing the dominant role. The location of the oil spill also affects the accumulation of the oil slick. At the Pai River Estuary, oil spills have the greatest impact on the ecological shoreline of Lake Chaohu, and spills during navigation affect the largest area of water. At the Baishi-Tianhe River Estuary, oil spills under various wind directions may cause pollution to the water intake in the southwest region of Lake Chaohu. Within 24 h, the oil spill comprehensive risk index is highest at the Pai River Estuary; within 72 h, the highest index is observed at the Baishi-Tianhe River Estuary. It is recommended that targeted response measures be implemented for high risk areas based on the oil slick drift characteristics at different spill locations, during different periods, and under the worst case wind conditions.
{"title":"A framework for assessing the pollution risk analysis of oil spill incidents on inland lakes: Oil spill models and case studies of Lake Chaohu, China","authors":"Zefu Liu , Aiping Huang , Bing Ma , Fei Dong , Xiaobo Liu","doi":"10.1016/j.rsma.2026.104775","DOIUrl":"10.1016/j.rsma.2026.104775","url":null,"abstract":"<div><div>As an essential function of the Yinjiang-Jihuai Project, shipping in the Lake Chaohu area faces potential risks of oil spills. In response to the increasing threat of oil spill impacts on the lake, a comprehensive framework for assessing oil spill risks in inland lakes has been proposed. This framework integrates lake fluid dynamics (oil spill modeling), the Environmental Sensitivity Index (ESI). The framework was applied to Chaohu Lake in China, where oil slick migration paths were simulated at multiple oil spill accident points along the Chao shipping segment. A lake oil spill comprehensive risk index method was proposed to assess the severity of oil spill incidents and quantify the impact of single wind directions on oil slick migration. The results indicate that both wind direction and the flow field jointly influence the migration of the oil slick, with wind direction playing the dominant role. The location of the oil spill also affects the accumulation of the oil slick. At the Pai River Estuary, oil spills have the greatest impact on the ecological shoreline of Lake Chaohu, and spills during navigation affect the largest area of water. At the Baishi-Tianhe River Estuary, oil spills under various wind directions may cause pollution to the water intake in the southwest region of Lake Chaohu. Within 24 h, the oil spill comprehensive risk index is highest at the Pai River Estuary; within 72 h, the highest index is observed at the Baishi-Tianhe River Estuary. It is recommended that targeted response measures be implemented for high risk areas based on the oil slick drift characteristics at different spill locations, during different periods, and under the worst case wind conditions.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"94 ","pages":"Article 104775"},"PeriodicalIF":2.4,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145981062","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Synthetic aperture radar (SAR) has emerged as a vital technology for detecting oil spills, even in challenging weather conditions. Deep learning models have demonstrated significant potential in leveraging SAR images for oil spill detection, owing to their robust feature extraction capabilities. However, considering the diversity of oil spill target scales and the extraction of global and local information, there are still particular challenges in accurately extracting oil spill areas from SAR images. Additionally, polarimetric information can significantly enhance the separability of oil films and seawater. To overcome these challenges, a Multi-scale Alignment and Fusion U-Shape Transformer Network (MAF-UFormer) is proposed, which enhances feature representation by integrating multi-scale fusion and agent attention mechanisms. To evaluate the effectiveness of MAF-UFormer, we perform experiments on the publicly available Deep-SAR Oil Spill Detection (SOS) dataset. The results demonstrate that MAF-UFormer achieves F1-Scores of 87.51 % and 83.03 % on the Sentinel-1 and PALSAR subsets of SOS, respectively. To further validate the robustness of MAF-UFormer, we create a new dataset, the Sentinel-1 Oil Spill Detection Dataset Part 1 (S1OSD-1). Experiments on S1OSD-1 demonstrate MAF-UFormer’s superior accuracy in oil spill detection, outperforming existing methods. Given SAR’s capability to extract polarimetric features that aid in distinguishing oil spills from seawater, we enhance S1OSD-1 by incorporating polarimetric data to construct Part 2 (S1OSD-2). On S1OSD-2, MAF-UFormer achieves an additional 1.68 % improvement in F1-Score over S1OSD-1. These results highlight the potential of MAF-UFormer for oil spill detection, offering vital technical support for oil spill emergency response and marine environmental protection.
{"title":"MAF-UFormer: Oil spill detection in SAR images using multi-scale alignment and fusion U-shaped transformer network","authors":"Caiyi Sun, Dawei Wang, Mingming Xu, Shiqing Wei, Shanwei Liu, Zhongwei Li","doi":"10.1016/j.rsma.2026.104773","DOIUrl":"10.1016/j.rsma.2026.104773","url":null,"abstract":"<div><div>Synthetic aperture radar (SAR) has emerged as a vital technology for detecting oil spills, even in challenging weather conditions. Deep learning models have demonstrated significant potential in leveraging SAR images for oil spill detection, owing to their robust feature extraction capabilities. However, considering the diversity of oil spill target scales and the extraction of global and local information, there are still particular challenges in accurately extracting oil spill areas from SAR images. Additionally, polarimetric information can significantly enhance the separability of oil films and seawater. To overcome these challenges, a Multi-scale Alignment and Fusion U-Shape Transformer Network (MAF-UFormer) is proposed, which enhances feature representation by integrating multi-scale fusion and agent attention mechanisms. To evaluate the effectiveness of MAF-UFormer, we perform experiments on the publicly available Deep-SAR Oil Spill Detection (SOS) dataset. The results demonstrate that MAF-UFormer achieves F1-Scores of 87.51 % and 83.03 % on the Sentinel-1 and PALSAR subsets of SOS, respectively. To further validate the robustness of MAF-UFormer, we create a new dataset, the Sentinel-1 Oil Spill Detection Dataset Part 1 (S1OSD-1). Experiments on S1OSD-1 demonstrate MAF-UFormer’s superior accuracy in oil spill detection, outperforming existing methods. Given SAR’s capability to extract polarimetric features that aid in distinguishing oil spills from seawater, we enhance S1OSD-1 by incorporating polarimetric data to construct Part 2 (S1OSD-2). On S1OSD-2, MAF-UFormer achieves an additional 1.68 % improvement in F1-Score over S1OSD-1. These results highlight the potential of MAF-UFormer for oil spill detection, offering vital technical support for oil spill emergency response and marine environmental protection.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"94 ","pages":"Article 104773"},"PeriodicalIF":2.4,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145980840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-12DOI: 10.1016/j.rsma.2026.104765
Olabanji Odunayo Aladejana , Babatunde Joseph Fagbohun , Israel Ropo Orimoloye , Akinola Adesuji Komolafe , Jimoh A. Ibrahim
Mangroves are highly productive intertidal ecosystems that provide vital services, including carbon sequestration, fisheries support, and coastal protection, which are essential for sustainable development in coastal regions. However, these ecosystems face increasing pressures from urban expansion, pollution, deforestation, and climate change. This study presents a continuous seven-year (2017–2023) geospatial analysis of mangrove dynamics across five key coastal regions in Nigeria using Sentinel-2 imagery processed within the Google Earth Engine (GEE) cloud-computing platform. To improve ecological accuracy, imagery was pre-processed using cloud masking and further filtered with the FES2014 tidal model to exclude observations acquired under unsuitable tidal conditions. Annual median NDVI composites were generated, and a decision-tree classification approach was used to map mangrove extent, integrating Global Mangrove Watch (GMW2020) data and field-calibrated spectral thresholds. Pixels were classified into mangrove, non-mangrove, or water based on ecologically meaningful NDVI and NDWI thresholds. Classification accuracy remained consistently high (88.89 %–95.19 %, Kappa: 0.78–0.90). The analysis revealed region-specific trends: slight net growth in Bayelsa, moderate decline in the Calabar–Cameroon region and Port Harcourt, minor but highly variable losses in Lagos, and relative stability in Warri. Notably, transitional and fragmented mangroves declined, indicating ecosystem degradation at the edges. These findings highlight the value of integrating Earth observation data with tidal context and cloud-based geospatial processing to inform targeted conservation, restoration, and coastal resource planning. The study underscores the need for regionally adaptive mangrove management strategies as part of broader sustainable development goals.
{"title":"Continuous annual monitoring of mangrove forest dynamics and sustainability implications in Nigeria: A seven-year remote sensing analysis using Sentinel-2, global mangrove watch, and tidal filtering","authors":"Olabanji Odunayo Aladejana , Babatunde Joseph Fagbohun , Israel Ropo Orimoloye , Akinola Adesuji Komolafe , Jimoh A. Ibrahim","doi":"10.1016/j.rsma.2026.104765","DOIUrl":"10.1016/j.rsma.2026.104765","url":null,"abstract":"<div><div>Mangroves are highly productive intertidal ecosystems that provide vital services, including carbon sequestration, fisheries support, and coastal protection, which are essential for sustainable development in coastal regions. However, these ecosystems face increasing pressures from urban expansion, pollution, deforestation, and climate change. This study presents a continuous seven-year (2017–2023) geospatial analysis of mangrove dynamics across five key coastal regions in Nigeria using Sentinel-2 imagery processed within the Google Earth Engine (GEE) cloud-computing platform. To improve ecological accuracy, imagery was pre-processed using cloud masking and further filtered with the FES2014 tidal model to exclude observations acquired under unsuitable tidal conditions. Annual median NDVI composites were generated, and a decision-tree classification approach was used to map mangrove extent, integrating Global Mangrove Watch (GMW2020) data and field-calibrated spectral thresholds. Pixels were classified into mangrove, non-mangrove, or water based on ecologically meaningful NDVI and NDWI thresholds. Classification accuracy remained consistently high (88.89 %–95.19 %, Kappa: 0.78–0.90). The analysis revealed region-specific trends: slight net growth in Bayelsa, moderate decline in the Calabar–Cameroon region and Port Harcourt, minor but highly variable losses in Lagos, and relative stability in Warri. Notably, transitional and fragmented mangroves declined, indicating ecosystem degradation at the edges. These findings highlight the value of integrating Earth observation data with tidal context and cloud-based geospatial processing to inform targeted conservation, restoration, and coastal resource planning. The study underscores the need for regionally adaptive mangrove management strategies as part of broader sustainable development goals.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"94 ","pages":"Article 104765"},"PeriodicalIF":2.4,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145981064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Microplastics (MPs) have emerged as a prevailing contaminant in aquatic environments, posing ecological risks and potential threats to human health due to their persistence and toxicity. Conventional remediation approaches are often constrained by high costs, limited efficiency and risk of secondary pollution. Recently, microalgae-derived (MD) biochar has gained attention as a sustainable and effective adsorbent for MP removal, with studies reporting removal efficiencies ranging from 60 % to 99 %, depending on MP type, size, surface chemistry, and operational conditions. Its high surface reactivity, cost-effectiveness and environmental compatibility make MD-biochar a promising alternative to conventional adsorbents. This review evaluates the potential of MD biochar in MP remediation, emphasizing how physicochemical properties such as porosity, functional groups and surface charge govern adsorption performance. Various microalgal species, such as Chlorella and Spirulina, have been explored as biochar precursors, offering unique structural and chemical properties that enhance MP removal. Production conditions, particularly pyrolysis temperature (450–750℃) and activation strategies, strongly influence biochar functionality. The mechanisms of MP adsorption, involving electrostatic attraction, hydrophobic partitioning and π-π interactions, are thoroughly discussed. Additionally, the review emphasizes the benefits of utilizing MD-biochar compared to conventional adsorbents, its ability to be regenerated and its ecological sustainability. Issues such as scalability, variations in MP composition are also discussed. Further studies should concentrate on defining common parameters, run pilot trials in diverse water matrices, integrating emerging tools such as AI-ML, carry out cost-benefit studies and stakeholder engagement.
{"title":"Microalgae-derived biochar for microplastic removal from aquatic systems: A comprehensive review and future perspectives","authors":"Ashrita Mohanty , Madhusmita Behera , Aditya Kishore Dash , Akshaya Kumar Verma","doi":"10.1016/j.rsma.2026.104767","DOIUrl":"10.1016/j.rsma.2026.104767","url":null,"abstract":"<div><div>Microplastics (MPs) have emerged as a prevailing contaminant in aquatic environments, posing ecological risks and potential threats to human health due to their persistence and toxicity. Conventional remediation approaches are often constrained by high costs, limited efficiency and risk of secondary pollution. Recently, microalgae-derived (MD) biochar has gained attention as a sustainable and effective adsorbent for MP removal, with studies reporting removal efficiencies ranging from 60 % to 99 %, depending on MP type, size, surface chemistry, and operational conditions. Its high surface reactivity, cost-effectiveness and environmental compatibility make MD-biochar a promising alternative to conventional adsorbents. This review evaluates the potential of MD biochar in MP remediation, emphasizing how physicochemical properties such as porosity, functional groups and surface charge govern adsorption performance. Various microalgal species, such as <em>Chlorella</em> and <em>Spirulina</em>, have been explored as biochar precursors, offering unique structural and chemical properties that enhance MP removal. Production conditions, particularly pyrolysis temperature (450–750℃) and activation strategies, strongly influence biochar functionality. The mechanisms of MP adsorption, involving electrostatic attraction, hydrophobic partitioning and π-π interactions, are thoroughly discussed. Additionally, the review emphasizes the benefits of utilizing MD-biochar compared to conventional adsorbents, its ability to be regenerated and its ecological sustainability. Issues such as scalability, variations in MP composition are also discussed. Further studies should concentrate on defining common parameters, run pilot trials in diverse water matrices, integrating emerging tools such as AI-ML, carry out cost-benefit studies and stakeholder engagement.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"94 ","pages":"Article 104767"},"PeriodicalIF":2.4,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-10DOI: 10.1016/j.rsma.2026.104770
Venkatesan Shiva Shankar , Neelam Purti , Pradip Panda , Kalyan De
Abandoned, lost, or otherwise discarded fishing gear (ALDFG) poses a significant threat to marine biodiversity globally, yet its impacts in remote island ecosystems remain poorly documented. This study provides the first baseline assessment of ALDFG interactions with threatened marine megafauna in the Andaman Islands, Bay of Bengal, using observations collected between 2020 and 2025. A total of 147 interactions were documented, of which sea turtles accounted for 88.4 % (n = 130). Olive Ridley turtles represented 69.2 % of turtle cases (n = 90) and Green turtles 28.5 % (n = 37), while Hawksbill and Leatherback turtles constituted the remaining 2.3 % (n = 3). Overall, 82.3 % of entangled turtles (n = 107) were rescued alive. Other affected taxa included the Andaman water monitor lizard (5.4 %, n = 8), Saltwater Crocodile (4.8 %, n = 7), and Dugong (1.4 %, n = 2). Fishing nets were responsible for 96.6 % of all interactions, with ropes accounting for the remaining 3.4 %. While many animals were successfully rescued (76.2 %, n = 112), several were found dead (23.8 %, n = 35) due to entanglement. These findings highlight the pervasive and under-reported threat of ALDFG to vulnerable marine fauna in the Andaman Islands. Mitigating ALDFG impacts requires a combination of improved gear reporting and retrieval systems, strengthened regulatory enforcement, capacity building of local fishing communities, and community-based monitoring to prevent gear loss and enhance conservation outcomes. Therefore, immediate policy interventions, coupled with awareness and engagement of local fishing communities, are essential to conserve marine wildlife in this ecologically sensitive region.
{"title":"Under-recognized impacts of abandoned, lost, and discarded fishing gear on threatened marine wildlife in the remote Andaman Islands, Bay of Bengal: A baseline study","authors":"Venkatesan Shiva Shankar , Neelam Purti , Pradip Panda , Kalyan De","doi":"10.1016/j.rsma.2026.104770","DOIUrl":"10.1016/j.rsma.2026.104770","url":null,"abstract":"<div><div>Abandoned, lost, or otherwise discarded fishing gear (ALDFG) poses a significant threat to marine biodiversity globally, yet its impacts in remote island ecosystems remain poorly documented. This study provides the first baseline assessment of ALDFG interactions with threatened marine megafauna in the Andaman Islands, Bay of Bengal, using observations collected between 2020 and 2025. A total of 147 interactions were documented, of which sea turtles accounted for 88.4 % (n = 130). Olive Ridley turtles represented 69.2 % of turtle cases (n = 90) and Green turtles 28.5 % (n = 37), while Hawksbill and Leatherback turtles constituted the remaining 2.3 % (n = 3). Overall, 82.3 % of entangled turtles (n = 107) were rescued alive. Other affected taxa included the Andaman water monitor lizard (5.4 %, n = 8), Saltwater Crocodile (4.8 %, n = 7), and Dugong (1.4 %, n = 2). Fishing nets were responsible for 96.6 % of all interactions, with ropes accounting for the remaining 3.4 %. While many animals were successfully rescued (76.2 %, n = 112), several were found dead (23.8 %, n = 35) due to entanglement. These findings highlight the pervasive and under-reported threat of ALDFG to vulnerable marine fauna in the Andaman Islands. Mitigating ALDFG impacts requires a combination of improved gear reporting and retrieval systems, strengthened regulatory enforcement, capacity building of local fishing communities, and community-based monitoring to prevent gear loss and enhance conservation outcomes. Therefore, immediate policy interventions, coupled with awareness and engagement of local fishing communities, are essential to conserve marine wildlife in this ecologically sensitive region.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"94 ","pages":"Article 104770"},"PeriodicalIF":2.4,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145980972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-10DOI: 10.1016/j.rsma.2026.104768
Claudinei José Rodrigues , Paulo Roberto Pagliosa , Aichely Rodrigues da Silva , Luis Carlos Pinto de Macedo Soares , João Alexandre Saviolo Osti , Cacilda Thais Janson Mercante , Alice Nunes Carvalho , Nei Kavaguichi Leite
The impacts of urban expansion on coastal regions can be mitigated through territorial governance instruments, particularly in Brazil, where master plans and the protection of coastal wetlands (e.g., estuaries and mangroves) play a critical role. These ecosystems provide essential regulatory and provisioning services but face increasing pressure from urbanization. To evaluate the effectiveness of Protected Areas (PAs) in conserving mangrove ecosystems, we analyzed a 28-year dataset (1992–2020; n = 552 samples). Additionally, we assessed whether mangroves mitigate urbanization-driven eutrophication in adjacent waters using the Trophic Index (TRIX). Our findings demonstrate that the establishment of the PA in 1992 significantly reduced mangrove loss. Long-term monitoring revealed that the waters within the mangrove ecosystem remained oligotrophic (TRIX < 4.0), whereas adjacent unprotected areas shifted to mesotrophic conditions (TRIX ≥ 4.0), underscoring the wetland’s role in buffering eutrophication. A generalized additive model (GAM) explained over 67 % of the observed variability in trophic state, highlighting the strong influence of land-use change. Simulations based on the current master plan project that a 100 % increase in the urbanized area, could elevate the system to hypereutrophic status (TRIX > 8.0), triggering cascade effects such as: toxic algal blooms, increased hypoxia, shifts in aquatic community structure, biodiversity loss, altered environmental metabolism and, disruption of biogeochemical cycles. These outcomes would compromise the ecosystem services provided by mangroves, emphasizing the need for policy interventions that integrate coastal wetland protection into urban planning.
{"title":"Urbanization, water quality and mangrove protection: A 28‑year assessment in the Tavares River watershed, southern Brazil","authors":"Claudinei José Rodrigues , Paulo Roberto Pagliosa , Aichely Rodrigues da Silva , Luis Carlos Pinto de Macedo Soares , João Alexandre Saviolo Osti , Cacilda Thais Janson Mercante , Alice Nunes Carvalho , Nei Kavaguichi Leite","doi":"10.1016/j.rsma.2026.104768","DOIUrl":"10.1016/j.rsma.2026.104768","url":null,"abstract":"<div><div>The impacts of urban expansion on coastal regions can be mitigated through territorial governance instruments, particularly in Brazil, where master plans and the protection of coastal wetlands (e.g., estuaries and mangroves) play a critical role. These ecosystems provide essential regulatory and provisioning services but face increasing pressure from urbanization. To evaluate the effectiveness of Protected Areas (PAs) in conserving mangrove ecosystems, we analyzed a 28-year dataset (1992–2020; n = 552 samples). Additionally, we assessed whether mangroves mitigate urbanization-driven eutrophication in adjacent waters using the Trophic Index (TRIX). Our findings demonstrate that the establishment of the PA in 1992 significantly reduced mangrove loss. Long-term monitoring revealed that the waters within the mangrove ecosystem remained oligotrophic (TRIX < 4.0), whereas adjacent unprotected areas shifted to mesotrophic conditions (TRIX ≥ 4.0), underscoring the wetland’s role in buffering eutrophication. A generalized additive model (GAM) explained over 67 % of the observed variability in trophic state, highlighting the strong influence of land-use change. Simulations based on the current master plan project that a 100 % increase in the urbanized area, could elevate the system to hypereutrophic status (TRIX > 8.0), triggering cascade effects such as: toxic algal blooms, increased hypoxia, shifts in aquatic community structure, biodiversity loss, altered environmental metabolism and, disruption of biogeochemical cycles. These outcomes would compromise the ecosystem services provided by mangroves, emphasizing the need for policy interventions that integrate coastal wetland protection into urban planning.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"94 ","pages":"Article 104768"},"PeriodicalIF":2.4,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145980843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-09DOI: 10.1016/j.rsma.2026.104756
Md. Rashedal Islam , Sukree Hajisamae , Siriporn Pradit , Muhammad Abdur Rouf , Sofiyudin Maae , Husneya Rensep
This study was conducted to determine the population structure, growth pattern, growth parameters, mortality, exploitation level, recruitment patterns, yield per-recruit (Y’/R), optimum catchable length (CWopt), and progression cohort of three sympatric mud crab species (Scylla olivacea, S. paramamosain, and S. tranquebarica) from the coastal areas of the Gulf of Thailand. Monthly sampling was conducted from May 2022 to June 2023 using traditional traps. Carapace width (CW) and body weight (BW) were digitally measured and analyzed with FiSAT-II software. CWopt was estimated using an empirical model based on maximum carapace length. The CW–BW relationship revealed significant deviations from isometry, showing positive allometric growth (b > 3, p < 0.001) for all three species. The estimated asymptotic parameters (CW∞, W∞, K) were 144.38 mm, 645.66 g, and 0.44 year−1 for S. olivacea; 160.13 mm, 1007.32 g, and 0.43 year−1 for S. paramamosain; and 160.13 mm, 914.99 g, and 0.15 year−1 for S. tranquebarica. The estimated natural mortality (M), fishing mortality (F), and exploitation (E) indicate overexploitation of S. olivacea (M = 0.69 year−1, F = 0.86 year−1, E = 0.56), whereas S. paramamosain (0.66, 0.37, 0.36) and S. tranquebarica (0.33, 0.11, 0.25) were underexploited. The peak recruitment occurred from December to February in S. olivacea, while S. paramamosain and S. tranquebarica exhibited similar peaks between October to December. These findings are crucial for developing science-based management strategies and conservation policies that ensure the sustainable use of these ecologically and economically valuable resources in the coastal ecosystems of the Gulf of Thailand.
研究了泰国湾沿岸3种同域泥蟹（Scylla olivacea、S. paramamosain和S. tranquebarica）的种群结构、生长模式、生长参数、死亡率、捕捞水平、捕蟹模式、每捕蟹产量（Y′/R）、最佳可捕长度（CWopt）和进展队列。2022年5月至2023年6月，采用传统诱捕器每月抽样。采用FiSAT-II软件对甲壳宽度（CW）和体重（BW）进行数字化测量和分析。使用基于最大甲壳长度的经验模型估计CWopt。CW-BW关系显示出与等距的显著偏差，所有三个物种均表现出正异速生长（b > 3, p <； 0.001）。估计的渐近参数（CW∞,W∞，K）分别为144.38 mm， 645.66 g和0.44 year−1；S. paramamosain为160.13 mm, 1007.32 g, 0.43 year−1；为160.13 mm, 914.99 g, 0.15 year−1。估计的自然死亡率(M)、捕捞死亡率(F)和开发利用(E)表明橄榄石棘鱼被过度开发（M = 0.69 year - 1, F = 0.86 year - 1, E = 0.56），而paramamosain棘鱼（0.66,0.37,0.36）和tranquebarica棘鱼（0.33,0.11,0.25）被过度开发。橄榄山棘虫的招募高峰出现在12 - 2月，而paramamosain和tranquebarica的招募高峰出现在10 - 12月。这些发现对于制定基于科学的管理战略和保护政策至关重要，这些战略和保护政策可确保泰国湾沿海生态系统中这些具有生态和经济价值的资源的可持续利用。
{"title":"Comparative population parameters and stock assessment of three symmetric Scylla species in coastal waters of the Gulf of Thailand","authors":"Md. Rashedal Islam , Sukree Hajisamae , Siriporn Pradit , Muhammad Abdur Rouf , Sofiyudin Maae , Husneya Rensep","doi":"10.1016/j.rsma.2026.104756","DOIUrl":"10.1016/j.rsma.2026.104756","url":null,"abstract":"<div><div>This study was conducted to determine the population structure, growth pattern, growth parameters, mortality, exploitation level, recruitment patterns, yield per-recruit (<em>Y’/R</em>), optimum catchable length (<em>CW</em><sub><em>opt</em></sub>), and progression cohort of three sympatric mud crab species (<em>Scylla olivacea, S. paramamosain,</em> and <em>S. tranquebarica</em>) from the coastal areas of the Gulf of Thailand. Monthly sampling was conducted from May 2022 to June 2023 using traditional traps. Carapace width (<em>CW</em>) and body weight (<em>BW</em>) were digitally measured and analyzed with FiSAT-II software. <em>CW</em><sub><em>opt</em></sub> was estimated using an empirical model based on maximum carapace length. The <em>CW–BW</em> relationship revealed significant deviations from isometry, showing positive allometric growth (<em>b > 3, p < 0.001</em>) for all three species. The estimated asymptotic parameters (<em>CW</em><sub><em>∞</em></sub>, <em>W</em><sub><em>∞</em></sub>, <em>K</em>) were 144.38 mm, 645.66 g, and 0.44 year<sup>−1</sup> for <em>S. olivacea</em>; 160<sup>.1</sup>3 mm, 1007.32 g, and 0.43 year<sup>−1</sup> for <em>S. paramamosain</em>; and 160.13 mm, 914.99 g, and 0.15 year<sup>−1</sup> for <em>S. tranquebarica</em>. The estimated natural mortality (<em>M</em>), fishing mortality (<em>F</em>), and exploitation (<em>E</em>) indicate overexploitation of <em>S. olivacea</em> (<em>M</em> = 0.69 year<sup>−1</sup>, <em>F</em> = 0.86 year<sup>−1</sup>, <em>E</em> = 0.56), whereas <em>S. paramamosain</em> (0.66, 0.37, 0.36) and <em>S. tranquebarica</em> (0.33, 0.11, 0.25) were underexploited. The peak recruitment occurred from December to February in <em>S. olivacea</em>, while <em>S. paramamosain</em> and <em>S. tranquebarica</em> exhibited similar peaks between October to December. These findings are crucial for developing science-based management strategies and conservation policies that ensure the sustainable use of these ecologically and economically valuable resources in the coastal ecosystems of the Gulf of Thailand.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"94 ","pages":"Article 104756"},"PeriodicalIF":2.4,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145980844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-09DOI: 10.1016/j.rsma.2026.104764
Cecilia Oyuga Olima , Chima Jude Iheaturu , Robert Marchant , Jessica P.R. Thorn , Claudia Capitani , Markus Fischer , Margaret Awuor Owuor
Land use and land cover change (LULCC) disrupts ecosystem structure and function, threatening ecosystem services and human well-being. Anticipating future trajectories is especially urgent in coastal regions, where mangrove ecosystems face anthropogenic and climatic pressures. In Lamu County, ongoing large-scale developments are expected to attract new settlements along the coastline and increase competition over land and natural resources, further intensifying pressures on mangroves. Here, we combine participatory scenario development with spatial modelling and ecosystem service valuation to explore plausible futures in Lamu County, Kenya. Using the Kesho, a diverse group of stakeholders co-produced four development scenarios to 2063, which were translated into spatially explicit LULCC maps using Landsat derived datasets and stakeholder-informed driver assumptions. A benefit transfer method was applied in two ways to estimate the value of mangroves’ provisioning, regulating and cultural services. Based on land-cover change alone, all scenarios show slight declines in value of ecosystem services. However, when scenario-specific changes in unit values were incorporated, the annual value diverged sharply, rising to USD 10.5 billion under the New Dawn scenario and falling to USD 7.6 billion under the Growth Trap. This study presents the first participatory scenario assessment in Lamu County, providing policy-relevant insights into how development pathways may shape mangrove ecosystems and the services they provide. Beyond Lamu, Kesho offers an adaptable tool for application in other mangrove-rich regions globally, supporting efforts to align local decision-making with continental and global sustainability agendas, including the African Union’s Agenda 2063 and the Sustainable Development Goals.
{"title":"Participatory scenarios and spatial modelling to explore mangrove ecosystem services futures in Lamu, Kenya","authors":"Cecilia Oyuga Olima , Chima Jude Iheaturu , Robert Marchant , Jessica P.R. Thorn , Claudia Capitani , Markus Fischer , Margaret Awuor Owuor","doi":"10.1016/j.rsma.2026.104764","DOIUrl":"10.1016/j.rsma.2026.104764","url":null,"abstract":"<div><div>Land use and land cover change (LULCC) disrupts ecosystem structure and function, threatening ecosystem services and human well-being. Anticipating future trajectories is especially urgent in coastal regions, where mangrove ecosystems face anthropogenic and climatic pressures. In Lamu County, ongoing large-scale developments are expected to attract new settlements along the coastline and increase competition over land and natural resources, further intensifying pressures on mangroves. Here, we combine participatory scenario development with spatial modelling and ecosystem service valuation to explore plausible futures in Lamu County, Kenya. Using the <em>Kesho</em>, a diverse group of stakeholders co-produced four development scenarios to 2063, which were translated into spatially explicit LULCC maps using Landsat derived datasets and stakeholder-informed driver assumptions. A benefit transfer method was applied in two ways to estimate the value of mangroves’ provisioning, regulating and cultural services. Based on land-cover change alone, all scenarios show slight declines in value of ecosystem services. However, when scenario-specific changes in unit values were incorporated, the annual value diverged sharply, rising to USD 10.5 billion under the New Dawn scenario and falling to USD 7.6 billion under the Growth Trap. This study presents the first participatory scenario assessment in Lamu County, providing policy-relevant insights into how development pathways may shape mangrove ecosystems and the services they provide. Beyond Lamu, <em>Kesho</em> offers an adaptable tool for application in other mangrove-rich regions globally, supporting efforts to align local decision-making with continental and global sustainability agendas, including the African Union’s Agenda 2063 and the Sustainable Development Goals.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"94 ","pages":"Article 104764"},"PeriodicalIF":2.4,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145981061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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