Regional Studies in Marine Science最新文献

{"title":"Mangrove species occurrence in relation to habitat types: Insights from the Maldives","authors":"Federico Cerri ,&nbsp;Yohan Didier Louis ,&nbsp;Eleonora Concari ,&nbsp;Rossella Nicolai ,&nbsp;Giulia Senna ,&nbsp;Shazla Mohamed ,&nbsp;Paolo Galli","doi":"10.1016/j.rsma.2026.105001","DOIUrl":"10.1016/j.rsma.2026.105001","url":null,"abstract":"<div><div>Mangroves are salt-tolerant woody plants forming coastal intertidal ecosystems throughout tropical and subtropical regions. Their distribution is commonly described along estuarine environmental gradients, with salinity and inundation identified as key drivers. However, in the Maldives, an oceanic archipelago lacking river systems, mangroves occur as small, fragmented stands of vegetation within closed or semi-enclosed water bodies, and their distribution patterns remain poorly understood despite the critical ecosystem services they provide. This study investigates species–habitat associations across 40 mangrove habitats, classified into embayment, pond-based, and marsh-based habitats, focusing on the occurrence of five dominant species: <em>Bruguiera cylindrica</em>, <em>B. gymnorrhiza</em>, <em>Lumnitzera racemosa</em>, <em>Ceriops tagal</em>, and <em>Rhizophora mucronata</em>. Water salinity was also measured to support interpretation of species distributions. Pearson’s Chi-square tests detected significant associations between species occurrence and habitat type for the five species (p &lt; 0.05), whereas differences in salinity among species were not statistically significant (Kruskal–Wallis test, p = 0.208). <em>B. cylindrica</em> (χ²=20.000, p &lt; 0.001) was strongly associated with marsh-based habitats, occurring in all surveyed systems of this type, whereas <em>B. gymnorrhiza</em> (χ²=6.578, p = 0.034) was less frequent there; both species was observed across a wide range of salinities. <em>L. racemosa</em> (χ²=8.189, p = 0.020) occurred most frequently in pond-based mangroves and was more often found in low to intermediate salinity conditions. In contrast, <em>R. mucronata</em> (χ²=11.779, p = 0.003) and <em>C. tagal</em> (χ²=23.022, p &lt; 0.001) were predominantly associated with embayment habitats, characterized by high salinity. These findings improve understanding of mangrove spatial distribution and provide guidance for habitat-specific conservation and restoration in the Maldives, where mangroves are critically endangered.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"97 ","pages":"Article 105001"},"PeriodicalIF":2.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147798943","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}

{"title":"Evaluating emission efficiency in container terminals: Indicator design and evidence from a coastal port in East China","authors":"Yifang Xu,&nbsp;Zekun Zhang,&nbsp;Ying Wang","doi":"10.1016/j.rsma.2026.105031","DOIUrl":"10.1016/j.rsma.2026.105031","url":null,"abstract":"<div><div>Improving the emission performance of container terminals is a strategic priority for port authorities pursuing decarbonization. However, the lack of standardized, dynamic assessment tools has hindered effective governance. Most existing energy and emission efficiency indicators are constructed from the perspective of a single entity or equipment type. Although such approaches may improve local carbon efficiency, they may lead to suboptimal performance at the terminal system level, highlighting the need for a comprehensive and unbiased system-wide evaluation framework. Drawing on the principles of the IMO's Energy Efficiency Design Index (EEDI), this study develops a velocity-integrated emission efficiency framework by proposing two novel indicators: the Emission Efficiency Index for Container Terminals (EEI-CT) for system-level performance and the Composite Emission Efficiency (CEE) for equipment-level assessment. This framework explicitly integrates carbon emissions, operational workload, and container handling velocity into a unified performance metric, enabling dynamic and cross-equipment comparability. An empirical analysis using a full year of data from a major electrified terminal in East China reveals significant efficiency heterogeneity across equipment types and generations, with summer temperatures causing notable performance degradation due to cooling demands. The study further quantifies that on-site photovoltaic integration improved the terminal’s EEI-CT by 4.64%, reducing annual CO₂ emissions by 981 tons. The proposed framework equips port managers and policymakers with a robust, scalable tool for strategic planning, enabling data-driven decisions in equipment benchmarking, targeted retrofitting, and low-carbon investment, thereby accelerating the maritime industry's transition to carbon neutrality.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"97 ","pages":"Article 105031"},"PeriodicalIF":2.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147798188","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}

{"title":"Atlantic blue crab (Callinectes sapidus Rathbun, 1896): Microplastic pollution indicator in invaded Mediterranean coastal ecosystems","authors":"S. Villoria-Calvo ,&nbsp;G. Blanco-Heras ,&nbsp;J. Gago ,&nbsp;A.V. Filgueiras ,&nbsp;C. Martínez-Gómez ,&nbsp;L. Viñas","doi":"10.1016/j.rsma.2026.105015","DOIUrl":"10.1016/j.rsma.2026.105015","url":null,"abstract":"<div><div>Plastic pollution has emerged as a pervasive global threat, impacting virtually all planetary ecosystems, from terrestrial to marine habitats. Plastic items smaller than 5 mm are known as microplastics (MPs). It is essential to assess the concentration of microplastics in marine organisms to understand their ecological impact and potential risks to food webs and human health. In this study, the Atlantic blue crab (<em>Callinectes sapidus</em> Rathbun, 1896), an invasive species established in the Mediterranean Sea, was selected as the target organism for analysis. The combined protocol of digestion by KOH 10% and H2O2 30% at 40ºC was employed to eliminate organic matter and maintain the characteristics of the polymers. In blue crabs, the gills, hepatopancreas and muscle were dissected, and the microplastic content was studied using an Agilent Technologies 8700 LDIR instrument (Chemical Imaging System). The average number of MPs was 17.28 ± 2.90 items/individual. The hepatopancreas showed the highest concentration of microplastics, in contrast to the muscle and gills. Fragments were the predominant type found (87.7%) and were mainly composed of polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), and polymethylmethacrylate (PMMA), indicating a close relationship with pollution sources. White was the most frequently observed color and the predominant size range was 100–299 µm. Data from this pilot assessment provide encouraging evidence for the use of <em>C. sapidus</em> as a microplastics sentinel, though extensive multi-site monitoring remains required to substantiate its role throughout the Mediterranean region.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"97 ","pages":"Article 105015"},"PeriodicalIF":2.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147798950","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}

{"title":"Integrated eDNA and conventional surveys of coral reef fishes at submerged banks, shoals, and offshore Islands in Southern Vietnam","authors":"Long Van Nguyen ,&nbsp;Quang Minh Thai ,&nbsp;Dat Xuan Mai ,&nbsp;Thinh Cong Tran ,&nbsp;My Thao Nguyen-Le ,&nbsp;Hong Kim Thi Phan ,&nbsp;Ben Xuan Hoang ,&nbsp;Ha Viet Dao ,&nbsp;Binh Thuy Dang ,&nbsp;Oanh Thi Truong ,&nbsp;Sang Quang Tran","doi":"10.1016/j.rsma.2026.105022","DOIUrl":"10.1016/j.rsma.2026.105022","url":null,"abstract":"<div><div>The integrating environmental DNA (eDNA) metabarcoding with traditional methods, such as underwater visual census (UVC) and piscicide-based specimen collection (SPC), offers enhanced opportunities for biodiversity assessment, particularly in logistically challenging deep-water coral reef environments. This study combined all three methods across 15 reef sites in Southern Vietnam, including eight submerged banks and shoals and two Con Dao offshore islands. A total of 70 UVC transects were completed, along with SPC using natural ichthyocide, and eDNA analysis of 98 filter-feeder samples (50 sponges, 48 bivalves). A total of 248 reef fish species were recorded, spanning 131 genera, 53 families, 27 orders, and 2 classes. Of these, 230 species were found at the submerged banks and shoals, and 99 species were recorded at the offshore islands, with higher diversity observed in southern locations. Species detection varied significantly by method: UVC recorded the most with 167 species (67.3%), followed by SPC with 70 species (28.2%), and eDNA with 58 species (23.4%). Minimal overlap was observed, with only three species (1.2%) detected by all three methods. Pairwise overlaps were also low: 14 species (6.6%) between eDNA and UVC, six species (4.9%) between eDNA and SPC, and 30 species (14.5%) between UVC and SPC. These findings demonstrate that each method provides a unique perspective on the community composition, confirming that the integration of all three is essential for a comprehensive and accurate assessment of reef fish diversity.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"97 ","pages":"Article 105022"},"PeriodicalIF":2.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147850333","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}

{"title":"Effect of thermal shock on the blood physiology and respiratory response in a coastal fish species (Mystus gulio) under hypoxia","authors":"Shaharier Ahmed ,&nbsp;Md. Harun-Ur-Rashid ,&nbsp;Md. Shamim Rahman ,&nbsp;Md. Nayeem Hossain ,&nbsp;Shahinur Akter ,&nbsp;Shifat Ara Noor ,&nbsp;Harunur Rashid ,&nbsp;Md. Mahiuddin Zahangir","doi":"10.1016/j.rsma.2026.105030","DOIUrl":"10.1016/j.rsma.2026.105030","url":null,"abstract":"<div><div>Climate change has emerged as a major driver of environmental stress, altering aquatic ecosystems through rising temperatures, hypoxia, and other stress-inducing factors. These changes significantly affect the physiology, behavior, and survival of aquatic species, particularly in coastal regions. <em>Mystus gulio,</em> a prominent ecologically and economically important coastal species, widely distributed and holds significant potential for coastal aquaculture in South Asian countries. This study evaluates the impact of thermal shock on the physiological and respiratory functions of <em>M. gulio</em> subjected to rapid temperature changes—cold shock at 21°C and heat shock at 33°C—under low oxygen (hypoxic) conditions from control (27°C) for a period of 24 h. The study recorded notable declines in dissolved oxygen levels and oxygen saturation, accompanied by a significant increase in oxygen consumption and opercular movements, indicating heightened respiratory activity under stress. Hematological assessments revealed a marked rise in glucose and white blood cell counts, while hemoglobin, cholesterol, and red blood cell levels were significantly reduced. Additionally, various erythrocytic abnormalities, including spindle-shaped, tear-drop, elongated, twin and triplet cells, along with erythrocytic nuclear irregularities such as micronuclei, notched nuclei, nuclear degeneration, and dead cells, were observed. These physiological disruptions underscore the vulnerability of <em>M. gulio</em> to sudden temperature fluctuations in hypoxic conditions, a challenge amplified by the growing frequency of extreme weather events linked to climate change. The findings emphasize the urgent need for climate-resilient aquaculture practices to minimize thermal stress and ensure the sustainability of coastal fisheries.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"97 ","pages":"Article 105030"},"PeriodicalIF":2.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147850334","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}

{"title":"Updated distribution and temporal insights from baited underwater videos on the invasive Bluespotted Cornetfish Fistularia commersonii in the Mediterranean Sea","authors":"Sara Bonanomi ,&nbsp;Carlo Cattano ,&nbsp;Marina Chiappi ,&nbsp;Marco Milazzo ,&nbsp;Francesco Tiralongo ,&nbsp;Ernesto Azzurro","doi":"10.1016/j.rsma.2026.105035","DOIUrl":"10.1016/j.rsma.2026.105035","url":null,"abstract":"<div><div>The Bluespotted Cornetfish, <em>Fistularia commersonii</em> Rüppell, 1838, is considered one of the most successful and rapidly spreading invaders of the Mediterranean Sea. In this study, building on the ORMEF (Occurrence Records of Mediterranean Exotic Fish) database, we present an updated overview of its non-indigenous distribution by integrating an exhaustive review of the published literature and by new records gathered from professional and recreational fishers, divers, and other citizens. In addition, we present novel occurrence data systematically collected using Baited Remote Underwater Video systems (BRUVs) in the Strait of Sicily between 2019 and 2024. Taken together, these observations support the presence of stable <em>F. commersonii</em> populations in the Central Mediterranean and point to an ongoing westward and northward expansion of its invasion front, evidenced by the rising number of records from southeastern Sicily (Ionian Sea) and the Strait of Sicily. The analysis of the information associated with the records highlights the significant contribution of citizen observations to the detection and monitoring of this species in the Mediterranean. Given its ecological impact and economic value as a fishery resource, both of which warrant careful investigation and proactive assessment, <em>F. commersonii</em> should be integrated into long-term surveillance strategies and adaptation plans.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"97 ","pages":"Article 105035"},"PeriodicalIF":2.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147850470","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}

{"title":"Microzooplankton in the Equatorial Southwestern Atlantic: establishing a baseline for a changing ocean","authors":"Ana Cecília Pinho Costa ,&nbsp;José Pedro Vieira Arruda Júnior ,&nbsp;Letícia Borges Leite ,&nbsp;Tatiane Martins Garcia ,&nbsp;Sigrid Neumann-Leitão ,&nbsp;Marcelo Oliveira Soares","doi":"10.1016/j.rsma.2026.105028","DOIUrl":"10.1016/j.rsma.2026.105028","url":null,"abstract":"<div><div>Assessing the impacts of environmental disturbances in tropical oligotrophic oceans is challenging due to the lack of historical data. Microzooplankton play a key role in these ecosystems, as energy flow is dominated by the microbial loop, yet studies on this group remain scarce, especially for nutrient-poor ocean zones. This research aimed to characterize the biomass, density, species richness, and composition of microzooplankton in the Equatorial Southwestern Atlantic (Brazil) using data collected two decades ago, establishing a historical baseline for future environmental assessments. This large-scale region is targeted for expansion of oil drilling, carbonate mining, and offshore wind farms. Samples were collected during the dry season from 32 stations across four cross-shelf transects (coastal, inner, middle, and outer shelf) using a 65 μm mesh net in an area of 4725 km². Temperature and dissolved oxygen was stable during sampling. Results show that both density and biomass declined from coastal to outer shelf, reflecting the increase of oligotrophic conditions, where coastal waters provide limited nutrients sufficient to sustain microzooplankton growth. However, species richness remained stable across the low-latitude area, indicating a homogeneous assemblage likely composed of taxa adapted to low-nutrient and high sea surface temperature (&gt; 26 ºC) conditions. Dominant taxa (≥75%) included copepods of the genus <em>Oithona</em>, mollusk larvae, and crustacean nauplii, highlighting the importance of small copepods in the microbial loop and the role of the tropical region as a nursery. These novel results provide the first baseline for microzooplankton in this important area, offering reference data for future studies of global environmental change and ecosystem management.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"97 ","pages":"Article 105028"},"PeriodicalIF":2.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147850477","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}

{"title":"Spatiotemporal dynamics of submerged macrophytes in a Black Sea coastal lagoons","authors":"Çağaşan Karacaoğlu ,&nbsp;Yasemin Saygı","doi":"10.1016/j.rsma.2026.105012","DOIUrl":"10.1016/j.rsma.2026.105012","url":null,"abstract":"<div><div>This study highlights the distinct short-term dynamics of submerged macrophytes in the two eutrophic coastal lagoons of Laka Balık and Uzungöl. Despite their proximity, the lakes exhibited notable differences in species composition, colonization patterns, and macrophyte development. Five submerged species were recorded, with <em>Potamogeton pectinatus</em> and <em>Chara vulgaris</em> dominating overall, while <em>Myriophyllum spicatum</em> occurred only in Uzungöl. Low species richness in both systems aligns with patterns typical of eutrophic shallow lakes, where high nutrient levels—particularly phosphorus (annual means &gt; 42 µg L⁻¹) —limit macrophyte diversity.Macrophyte biomass, coverage, and PVI differed significantly between the two lagoons, driven primarily by variations in depth, turbidity, and chlorophyll-a. During the peak summer colonization, the shallower Uzungöl supported substantially higher mean macrophyte biomass (4214 g m⁻²), coverage (73.3%), and PVI (58.1%) compared to Lake Balık (1317 g m⁻², 23.3%, and 9.6%, respectively). High turbidity restricted colonization in deeper zones of Lake Balık whereas clearer, shallower regions, especially in Uzungöl, supported higher macrophyte abundance. Species-specific analyses revealed that salinity and depth further shaped distribution patterns, with <em>C. vulgaris</em> favoring less saline shallows, <em>P. pectinatus</em> thriving in moderately saline clear waters, and <em>Najas graminea</em> showing broad salinity tolerance.NDVI-based remote sensing analysis (validated with field data, r ≥ 0.50, p = 0.01) revealed pronounced interannual changes in Lake Balık, with a steady increase in vegetation cover from 2006 to 2012, followed by a decline, while Uzungöl remained relatively stable. Overall, the findings underscore the combined influence of eutrophication, turbidity, salinity, and depth on submerged macrophyte communities and highlight the importance of these factors in lagoon management and conservation.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"97 ","pages":"Article 105012"},"PeriodicalIF":2.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147850478","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}

{"title":"Retention of floating macroplastics in semi-enclosed coastal systems: Insights from modeling and drifter experiments","authors":"Bruna de Ramos ,&nbsp;Gabriela Escobar-Sánchez ,&nbsp;Daniel González-Fernández ,&nbsp;Ulf Gräwe ,&nbsp;Xaver Lange ,&nbsp;Gerald Schernewski","doi":"10.1016/j.rsma.2026.105014","DOIUrl":"10.1016/j.rsma.2026.105014","url":null,"abstract":"<div><div>Coastal and estuarine systems can retain floating macroplastics before they reach the open sea, yet these environments are often underrepresented in marine litter monitoring and assessments. We investigated floating macroplastic retention under six wind conditions and over a year in two semi-enclosed Baltic Sea systems (the Warnow Estuary and Greifswald Bay). We used high-resolution (20 m and 200 m) 2D hydrodynamic models with Lagrangian particle tracking, adding retention based on entrapment observed in drifter experiments in the reed belts. Model results were compared to in situ surface drifter trajectories in the Warnow Estuary. Drifter trajectories under two contrasting wind conditions closely matched the modeled accumulation patterns and travel times. Annual retention of simulated particles exceeded 80% in both systems, while short-term (72 h) retention reached up to 100% in the Warnow Estuary. Reed belts were the primary retention zones, whereas artificial structures also contributed to retention. Extrapolating our results to the Baltic Sea, macroplastic retention in coastal and estuarine systems may be at least 50% lower than previous estimations (38 million items compared to the 76 million items per year reported from previous studies)</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"97 ","pages":"Article 105014"},"PeriodicalIF":2.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147798187","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}

{"title":"Green turtle foraging patterns revealed by seagrass meadow-centric time-lapse camera and drone surveys","authors":"Hideaki Nishizawa ,&nbsp;Junichi Okuyama ,&nbsp;Haruki Murai ,&nbsp;Naoya Noguchi ,&nbsp;Iwao Tanita","doi":"10.1016/j.rsma.2026.105016","DOIUrl":"10.1016/j.rsma.2026.105016","url":null,"abstract":"<div><div>The recent repression of seagrass meadows threatens multiple ecosystem services. Seagrass overgrazing by herbivorous animals, such as green turtles (<em>Chelonia mydas</em>), may contribute to seagrass repression. Therefore, the foraging ecology of green turtles is important for understanding their interactions with seagrass meadows and assessing the sustainability of seagrass ecosystems. The diel cycle is a major driving factor of green turtle foraging patterns; however, tidal effects remain less well understood. This study aimed to clarify the influence of diel and tidal cycles on green turtle foraging in seagrass meadows by integrating time‑lapse camera and drone surveys. Specifically, the timing and density of green turtle visits to a seagrass meadow on Ishigakijima Island, Yaeyama Islands, Japan, were investigated during 2023–2024. The presence or absence of green turtles in the time-lapse camera data indicated that the bimodal diel foraging activities peaked at 6:00–08:00 and 16:00–18:00. In addition, the green turtle observation probability in the time-lapse camera data and the density estimated from the drone surveys increased as the tide level increased. The results showed that more green turtles aggregated to forage in the seagrass meadow when access to seagrass was available during high tide. Furthermore, green turtle density tended to increase during these two years. The seagrass meadow-centric approach using time-lapse camera and drone surveys is set to complement individual-based biotelemetry and biologging techniques to reveal green turtle foraging ecology. This approach is also important for monitoring herbivores in seagrass meadows and considering their coexistence and conservation management.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"97 ","pages":"Article 105016"},"PeriodicalIF":2.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147798236","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}