Regional Studies in Marine Science最新文献

{"title":"First record of Cassiopea xamachana ephyrae from the wild in India, with insights into its life history and development","authors":"L. Ranjith ,&nbsp;Raju Saravanan ,&nbsp;K.S. Sobhana ,&nbsp;I. Jagadis ,&nbsp;S. Ramkumar ,&nbsp;C. Kalidas ,&nbsp;D. Linga Prabu ,&nbsp;M. Kavitha ,&nbsp;P. Nevathitha ,&nbsp;A. Mathan Babu ,&nbsp;D. Sarathapriya ,&nbsp;L. Loveson Edward ,&nbsp;Grinson George","doi":"10.1016/j.rsma.2026.104786","DOIUrl":"10.1016/j.rsma.2026.104786","url":null,"abstract":"<div><div>The upside-down jellyfish <em>Cassiopea</em> spp. (Scyphozoa: Rhizostomeae) displays a metagenetic life cycle comprising medusoid and polyp stages, with the ephyrae as an intermediate stage. This study reports, for the first time, the occurrence of wild <em>Cassiopea</em> ephyrae from Indian waters with different developmental morphologies under a controlled rearing system. Ephyrae was collected from the primary settlement unit of a slow sand filter facility supplied source seawater from Tuticorin Bay on the southeastern coast of India. The molecular results showed a close identity to <em>Cassiopea xamachana</em> (<span><span>Bigelow, 1892</span></span>), with 99.54 % similarity in the COI gene sequence analysis. The distinct characteristics of the newly liberated ephyrae (1.4–2.5 mm) included a long manubrium (more than half of the central disc diameter), 16 spatula-shaped velar lappets, and 32 outwardbent rhopalial lappets with zooxanthellae distributed in the mesoglea. The development of ephyrae into young medusae occurred within 3–4 days under controlled laboratory conditions. This study revealed that ephyrae readily accepted live feed and exhibited substantial growth and morphogenesis in young medusae. This study provides insights into the critical early-life parameters of <em>C. xamachana</em>, which are essential for understanding its swarming behavior in the wild.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"95 ","pages":"Article 104786"},"PeriodicalIF":2.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146191208","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":"The silent drift of PAHs in the East China Sea: Sources, ecological risks, and remediation","authors":"Liberty Chidewe ,&nbsp;Rongrong Zhang ,&nbsp;Lord Famiyeh ,&nbsp;Kalim Ullah ,&nbsp;Qunying Lu ,&nbsp;Zeming Zhang ,&nbsp;Xizhi Shi","doi":"10.1016/j.rsma.2026.104826","DOIUrl":"10.1016/j.rsma.2026.104826","url":null,"abstract":"<div><div>This review synthesizes two decades (2004–2024) of research on polycyclic aromatic hydrocarbons (PAHs) in the East China Sea (ECS), focusing on their occurrence, sources, risks, and remediation. Using a PICO-guided systematic approach, we compiled data across seawater, sediments, biota, and food webs. PAH concentrations in seawater range from non-detectable to 816.9 ng/L, while sediments span 1.7–3047.1 ng/g, with ecological risk quotients generally indicating low to moderate risk (RQ ≤ 1). Biota exhibit PAH levels up to 3500 ng/g, revealing notable bio-accumulation, and benzo[<em>a</em>]pyrene Toxicity Equivalency Quotient (TEQ_BaP) values from 1960 to 2020 sediment cores (0.34–5.4 ng/g) remain far below the 600 ng/g toxicity threshold, suggesting limited carcinogenic pressure at the sediment level. Nevertheless, seafood-based excess cancer risk (ECR) values between 1.10E-7 and 5.08E-5, with some exceeding 1.0E-6, point to potential long-term human health concerns. Source apportionment indicates that oil spills, petroleum and coal combustion, steel production, and other industrial emissions are the dominant contributors, with spatial hotspots linked to high population density and GDP. The review also evaluates remediation options—including bio-remediation, adsorption, advanced oxidation processes, sediment capping, and photo-degradation—and discusses their feasibility under ECS-specific hydrodynamic and ecological conditions. Overall, the ECS currently exhibits low to moderate PAH pollution on both regional and global scales; however, strengthened monitoring, locally adapted risk assessment frameworks, and targeted remediation strategies remain essential.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"95 ","pages":"Article 104826"},"PeriodicalIF":2.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146191217","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":"Spatio-temporal dynamics for dolphinfish (Coryphaena hippurus) in the waters around Taiwan: Implications for stock assessment and fisheries management","authors":"Wen-Qi Xu ,&nbsp;Sheng-Ping Wang ,&nbsp;Chih-Yu Lin ,&nbsp;Wei-Chuan Chiang ,&nbsp;Toshihide Kitakado","doi":"10.1016/j.rsma.2026.104832","DOIUrl":"10.1016/j.rsma.2026.104832","url":null,"abstract":"<div><div>Understanding the spatio-temporal dynamics of dolphinfish (<em>Coryphaena hippurus</em>) is essential for effective stock assessment and fisheries management. Owing to its migratory nature, rapid growth, and short lifespan, the species requires management approaches that account for spatial and temporal variability. In this study, two spatio-temporal modelling frameworks, VAST and sdmTMB, were applied to longline fishery logbook data collected in the waters around Taiwan from 2011 to 2023. Standardised indices of relative abundance were estimated using an area-weighted approach that accounted for both fished and unfished regions. Cluster analysis was conducted to classify fishing strategies based on species composition, revealing a dominant dolphinfish-targeted cluster concentrated in the eastern offshore region. Both spatio-temporal models detected consistent seasonal patterns, with peak abundance in the second quarter and a decline in the third, aligning with known migratory behaviour and oceanographic influences. Spatial hotspots were identified primarily in the northeastern waters influenced by the Kuroshio Current. While general agreement was observed between the models, sdmTMB produced higher spatial contrast and slightly greater abundance estimates in the early years. Differences in model structure, spatial resolution, and data coverage were found to influence predictive outcomes. Limitations regarding logbook data quality, spatial bias, and the absence of environmental covariates were acknowledged. Nevertheless, the results demonstrate the utility of spatio-temporal modelling in deriving robust abundance indices and identifying biologically and operationally significant fishing grounds that represent key habitats and high-effort zones for dolphinfish fisheries in the northwestern Pacific. These findings provide a strong basis for integrating spatial dynamics into stock assessments and support the development of adaptive, spatially explicit management strategies in the western Pacific.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"95 ","pages":"Article 104832"},"PeriodicalIF":2.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146191211","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":"Ecological risk assessment and trace metal distribution in surface water and sediments of the Bay of Bengal, India","authors":"Shanmugasundharam Arumugam ,&nbsp;Sivakumar Karthikeyan ,&nbsp;Ramachandran Annathurai ,&nbsp;Saubhagya Ranjan Mahapatra","doi":"10.1016/j.rsma.2026.104789","DOIUrl":"10.1016/j.rsma.2026.104789","url":null,"abstract":"<div><div>The current study assesses the spatial variability of physicochemical parameters, nutrients, and the distribution of trace metals in surface water and benthic sediments along the offshore Cuddalore region of the Bay of Bengal, India, and evaluates the associated ecological risk. Twenty-five surface water and sediment samples were collected between Cuddalore Harbour and Port Nova, an area impacted by industrial and residential effluents discharged via the Uppanar and Gadilam Rivers. Water analysis revealed a cation abundance order of Na &gt; K &gt; Mg &gt; Ca, with nutrient concentrations ranging from 0.45 to 4.30 mg/l for nitrate and between 0.81 and 2.65 mg/l for phosphate, suggesting localized nutrient enrichment. Ecological risk indices applied to sediments indicated significant contamination: The Contamination Factor (CF) and Enrichment Factor (EF) for Cadmium (Cd) were consistently extreme (EF_mean ̴ 65), classifying the sediments as very severely contaminated and underscoring a non-crustal, anthropogenic source. Nickel (Ni) concentrations in the water column were found to be 4–6 times higher than established regional averages for the Bay of Bengal coast, also pointing to specific anthropogenic input. Principal Component Analysis (PCA) confirmed source differentiation: PC1 ( ̴ 34.25 % variance) showed high positive loadings for Fe, Mn, Cr, Cu, Ni, Pb, and Zn indicating a common lithogenic/anthropogenic source strongly controlled by fine-grained sediment texture. Significant positive correlations were observed between key pollutants (Co-Pb &gt;0.80; Ni-Cd = 0.70), further supporting a common industrial origin. The systematic assessment concludes that anthropogenic activities are the main driver of increased trace metal content, posing a significant ecological threat to the coastal ecosystem.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"95 ","pages":"Article 104789"},"PeriodicalIF":2.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146057414","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":"Source characterisation of the trace metal composition in coastal sediments from Andaman and Nicobar Islands","authors":"V. Sachithanandam ,&nbsp;Kiran Kumar Reddy ,&nbsp;S. Sai Elangovan ,&nbsp;P.M. Mohan ,&nbsp;B.S.K. Kumar ,&nbsp;G. Deviram ,&nbsp;N.V. Vinithkumar","doi":"10.1016/j.rsma.2026.104862","DOIUrl":"10.1016/j.rsma.2026.104862","url":null,"abstract":"<div><div>The Andaman and Nicobar Islands, located at the Indian and Pacific lithospheric plates intersection, host diverse ecosystems such as coral reefs, mangroves, and seagrass beds. In this study an attempt was made to provide baseline data for the selected trace metal concentrations and possible sources in surface sediment samples collected from 35 sites of South Andaman Island. Based on the geochemical classification, the results of trace metal concentrations revealed higher lithophile trace metal concentrations than chalcophile and siderophile metals, indicating a geogenic source. Further, the calculated indices like Enrichment Factor, and Geo-accumulation Index confirmed minimal anthropogenic impact. On the other hand, Pollution Load Index has showed moderate As and Pb enrichment only in urbanized areas like Guptapara and Junglighat. Remote sites such as Jolly Buoy Island showed minimal contamination, which emphasizing the interplay of natural and human influences on sediment quality and the need for detailed and long-term environmental monitoring and management.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"95 ","pages":"Article 104862"},"PeriodicalIF":2.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147422945","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":"First data on the family Dulichiidae (Amphipoda: Senticaudata) from communities of the Piip submarine volcano, the Bering Sea, with the description of a new species of Dulichiopsis","authors":"Pavel A. Kireev,&nbsp;Olga A. Golovan","doi":"10.1016/j.rsma.2026.104877","DOIUrl":"10.1016/j.rsma.2026.104877","url":null,"abstract":"<div><div>During ROV surveys of the communities of the Piip submarine volcano in the Bering Sea, amphipods of the family Dulichiidae were observed in high abundance (up to ∼ 120 masts per 1 m²). Specimens sampled at a depth of 407 m on the northern summit were found to represent a new species, <em>Dulichiopsis ogo</em> sp. nov., which is described here. <em>Dulichiopsis ogo</em> sp. nov. most closely resembles <em>D. barnardi</em> Laubitz, 1977 known from the bathyal zone of the northeastern Pacific by having more developed eyes than in other congeners, and an unusually long urosomite 1 (which is longer than pleonites 1–3 combined). The new species can be distinguished from all known congeners by the presence of a dorsolateral suture between pereonites 6 and 7 and three apical spine teeth on the maxilliped inner plate. The taxonomic composition of the genus Dulichiopsis is discussed</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"95 ","pages":"Article 104877"},"PeriodicalIF":2.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147421809","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":"Sedimentary phosphorus deposits in a southern Caribbean gulf during the last millennium","authors":"Alex Rúa ,&nbsp;Kelis Romaña ,&nbsp;Paula Quiceno ,&nbsp;Juan P. Serna ,&nbsp;Juan Fernando Gómez ,&nbsp;Elisabeth Pohlon ,&nbsp;Heazel Grajales","doi":"10.1016/j.rsma.2026.104857","DOIUrl":"10.1016/j.rsma.2026.104857","url":null,"abstract":"<div><div>This study reconstructs the evolution of sedimentary phosphorus (P) in the Gulf of Urabá using three sediment cores spanning the last millennium. Total (TP), inorganic (IP), and organic phosphorus (OP) were quantified and evaluated in relation to sediment granulometry, estuarine hydrography, and climate periods viz., Medieval Warm Period (MWP), Little Ice Age (LIA), and Current Warm Period (CWP). TP and IP were determined by spectrophotometry after calcination and HCl extraction. OP was calculated as the difference between TP and IP. P deposition was seemingly controlled by fluvial transport and sedimentation rates, with minor contribution from in situ biological assimilation. OP dominated at all sites (67–90 %), particularly in muddy facies associated with lower-energy depositional environments. Distinct TP and IP peaks during MWP–LIA and LIA–CWP transitions are consistent with episodic increases in rainfall intensity and sediment transport. Principal component analysis (PCA) indicated an association between granulometry, P speciation, and fluvial discharge modulated by climate variability. This study provides the first high-resolution sedimentary P record in the gulf, showing that long-term P accumulation is dominated by physical transport and modulated by climate variability and land-use change.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"95 ","pages":"Article 104857"},"PeriodicalIF":2.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147422281","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":"Differential presence of microplastics in the gastrointestinal tract of tropical fish in relation to trophic levels","authors":"Merle M. Borges-Ramírez,&nbsp;Rosa E. Martínez-Cerda,&nbsp;Carlos E. Paz-Ríos,&nbsp;Edgar F. Mendoza-Franco,&nbsp;Atahualpa Sosa-López,&nbsp;Jaime Rendón-von Osten","doi":"10.1016/j.rsma.2026.104836","DOIUrl":"10.1016/j.rsma.2026.104836","url":null,"abstract":"<div><div>Tropical marine fish with different trophic levels were studied to determine the quantity and distribution of microplastics in their intestinal tracts. Eight hundred eighty-eight individual fish representing eleven species used for human consumption in Campeche (southern Gulf of Mexico) were examined. A total of 745 microplastics were found with an average of 0.83 ± 1.83 MPs∙individual⁻¹. Among the microplastics detected, fragments were the most prevalent (54.89 %), and black microplastics were most frequently found in 44.83 % of the fish. The most abundant polymers identified were polyethylene vinyl acetate (PEVA), polybutadiene+naphthenic oil (PB+NO), and polyethylene/propylene/diene (EPDM). Furthermore, a greater abundance of smaller microplastics (0.25–0.5 mm) was found in organisms at low (TL 2.5) and medium (TL 2.9) trophic levels, unlike organisms with high TL. Our results show that microplastics are widespread in the food web of the tropical coastal fish assemblage analyzed.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"95 ","pages":"Article 104836"},"PeriodicalIF":2.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146191160","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":"Harnessing cloud-based SAR earth observation and GNOME numerical simulation for modelling the MSC ELSA III oil spill trajectory: Insight from the Kochi coast in south-eastern Arabian sea","authors":"Binay Bhattacharya ,&nbsp;SK Ariful Hossain ,&nbsp;Moumita Ghosh ,&nbsp;Swapnil Das","doi":"10.1016/j.rsma.2026.104844","DOIUrl":"10.1016/j.rsma.2026.104844","url":null,"abstract":"<div><div>A Liberian container vessel, <em>MSC ELSA III,</em> had capsized 38 nautical miles off Kochi on May 25, 2025, releasing oil and cargo in the southeastern Arabian Sea. This study investigated the trajectory and eventual fate of this oil spill, focusing on the key driving forces. The spill was simulated using GNOME numerical model through a series of control and sensitivity experiments focusing on the diffusion coefficient and the influence of wind and current movers. A control experiment, validated with both winds and currents from Sentinel-1 imagery, showed that a diffusion coefficient of 1000 m²/s accurately replicated the actual slick in terms of lateral spread. The simulated spill at 00:00 UTC on May 28 was positioned near the observed spill at 00:41 UTC on the same date. The combined impact of winds and currents predominantly steered the oil spill in a south-eastward direction while slowly approaching the shore, highlighting their critical role in modulating the spill’s transport and dispersion pathways. Moreover, the sensitivity experiment demonstrated that winds alone transported the spill towards the shore, whereas currents alone induced a south-eastward drift of the spill that kept the oil offshore. This study further indicated that evaporation and beaching were the predominant processes, with evaporation peaking at 48 % within the first 4 h and beaching accounting for 51 % of the spill after 72 h. Therefore, this study provided valuable insights into spill fate and behaviour, supported timely response in mitigation efforts to protect ecologically sensitive coastal environments, and advanced multiple UN SDGs.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"95 ","pages":"Article 104844"},"PeriodicalIF":2.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146191283","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":"Identifying potential investable ports along the Maritime Silk Road from the perspective of supply-demand balance","authors":"Yanbin Yang ,&nbsp;Ling Sun ,&nbsp;Zhong Ning ,&nbsp;Wenjing Zhang ,&nbsp;Kaiyuan Li","doi":"10.1016/j.rsma.2026.104845","DOIUrl":"10.1016/j.rsma.2026.104845","url":null,"abstract":"<div><div>With the advancement of the 21st Century Maritime Silk Road (MSR) initiative, Chinese enterprises have actively participated in the construction and operation of ports along the MSR, significantly enhancing maritime connectivity. As the MSR enters a new phase of high-quality development, overseas port investment faces higher standards. Achieving supply-demand balance of port is critical for sustainable development, as it contributes to improved operational efficiency, resource optimization and financial stability. This study focuses on container ports along the MSR and proposes quantitative methods to evaluate port demand and supply. Port demand is measured by container throughput, while supply is inferred from operational performance indicators. A systematic method to evaluate the supply-demand balance status of global ports is then conducted and 581 global ports are classified into five categories. Results show that 65.58 % of these ports are in a relatively balanced status, while 14.29 % face supply shortages. Focusing on 366 ports along the MSR, the study identifies 19 potential investable ports with significant supply shortages. Additionally, 18 ports are selected as potential alternatives for these 19 ports based on geographic proximity, throughput comparability and supply adequacy. The findings provide theoretical support for optimizing port resource allocation and improving network resilience, offering a data-driven basis for Chinese enterprises to make informed overseas investment decisions.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"95 ","pages":"Article 104845"},"PeriodicalIF":2.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146191209","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}