Regional Studies in Marine Science最新文献

{"title":"Deciphering the mechanisms of polystyrene microplastic-induced toxicity in Litopenaeus vannamei: An integrated transcriptomic and microbiomic investigation","authors":"Miao Zhu ,&nbsp;Xuejie Wang ,&nbsp;Danqing Hou ,&nbsp;Shan Gao ,&nbsp;Jianbo Yu ,&nbsp;Jichen Zhao ,&nbsp;Chengbo Sun","doi":"10.1016/j.rsma.2026.105010","DOIUrl":"10.1016/j.rsma.2026.105010","url":null,"abstract":"<div><div>Polystyrene microplastics (PS-MPs) pose a significant threat to marine organisms and aquaculture safety; PS-MPs pose a significant threat to marine organisms and aquaculture safety; however, the mechanisms underlying their sublethal toxicity in shrimp remain incompletely understood.This study investigated the effects of subacute exposure (21 days) to different concentrations of PS-MPs (0, 0.1, 1, and 5 mg·L⁻¹) on <em>Litopenaeus vannamei</em> using integrated approaches, including histopathology, enzyme activity assays, transcriptomics, and 16S rRNA sequencing. Results demonstrated that PS-MPs induced intestinal damage in a concentration-dependent manner, manifested by epithelial cell detachment, basement membrane thinning, and villi reduction. High-concentration exposure (5 mg·L⁻¹) significantly suppressed antioxidant enzyme activities (SOD and CAT) and increased malondialdehyde (MDA) levels, indicating oxidative damage. Transcriptomic analysis revealed significant enrichment of immune- and metabolism-related pathways, such as complement and coagulation cascades, lysosome, antigen processing and presentation, and carbon metabolism. PS-MPs exposure triggered intestinal oxidative stress and inflammatory responses in <em>L. vannamei</em>, disrupting the integrity of the intestinal mucosal barrier, which in turn induced significant changes in the intestinal microbial community structure，The microbiome results also confirm this finding，characterized by shifted relative abundances of dominant phyla, increased abundance of conditional pathogens such as Vibrio, and decreased microbial community diversity. These findings collectively demonstrate that PS-MPs impair intestinal integrity, disrupt antioxidant capacity, alter metabolic functions, and induce microbial dysbiosis, These findings indicate that PS-MPs impair intestinal integrity, disturb antioxidant defense, alter metabolic processes, and induce gut microbial dysbiosis in <em>L. vannamei.</em></div><div>This study provides critical insights into the toxic mechanisms of PS-MPs in <em>L. vannamei</em> and establishes a theoretical foundation for mitigating microplastic-related risks in sustainable aquaculture.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"97 ","pages":"Article 105010"},"PeriodicalIF":2.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147850395","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":"Disrupted sediment pathways and coastal erosion governance: Integrating riverine dynamics and livelihood-dependent community perception along Sri Lanka’s southwestern coast","authors":"Dilshan Vithanage ,&nbsp;R.S.M. Samarasekara ,&nbsp;Charmalie Nahallage ,&nbsp;Hasitha Siriwardana ,&nbsp;J.K.V. Karunathilaka ,&nbsp;S.M.L.M.B. Samarakoon ,&nbsp;T.S.B. Wedagedara ,&nbsp;D.M.S. Murage ,&nbsp;N. Pathinayake","doi":"10.1016/j.rsma.2026.105038","DOIUrl":"10.1016/j.rsma.2026.105038","url":null,"abstract":"<div><div>Coastal erosion along river-influenced shorelines results from complex interactions between altered sediment dynamics and human interventions, yet management strategies often rely on fragmented physical or social assessments. This study investigates coastal erosion along the Bentota-Colombo Port City coastline in Southwest Sri Lanka by integrating empirical sediment transport analysis of the Kalu River system with an assessment of coastal stakeholder perceptions. Sediment transport patterns were analysed to quantify changes in river-coast connectivity, particularly following the 2017 estuarine modification, while community perceptions were evaluated using structured surveys and stakeholder engagement across multiple coastal user groups. Results indicate that riverine and estuarine modifications have altered sediment flux pathways, contributing to sediment deficits along adjacent beaches and exacerbating shoreline instability. Conversely, stakeholder perceptions of erosion drivers are primarily shaped by visible coastal interventions, such as hard engineering structures and large-scale developments, while upstream sediment processes remain underrecognized. This mismatch between measured sediment dynamics and public understanding influences management preferences, often favouring reactive, site-specific engineering solutions over holistic strategies. By linking physical sediment evidence with community perceptions, the study demonstrates how gaps between scientific knowledge and social interpretation can undermine the effectiveness and legitimacy of coastal management interventions. The findings emphasize the need for integrated, source-to-sink governance approaches that align sediment management strategies with stakeholder awareness and participation. This framework provides actionable insights for erosion management in monsoon-dominated, data-limited coastal systems undergoing rapid development.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"97 ","pages":"Article 105038"},"PeriodicalIF":2.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147850396","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":"Under the radar: A contemporary assessment of Bahamian batoids","authors":"Natascha Wosnick ,&nbsp;Ariana Hamilton-Bakke ,&nbsp;Tamara Dörfer ,&nbsp;Patricia Charvet ,&nbsp;Diana K. Mongare ,&nbsp;Eric VC Schneider ,&nbsp;Owen R. O’Shea","doi":"10.1016/j.rsma.2026.105023","DOIUrl":"10.1016/j.rsma.2026.105023","url":null,"abstract":"<div><div>Batoids comprise a diverse group of elasmobranchs that remain comparatively understudied despite increasing global conservation concern. This study evaluates the completeness of current knowledge on batoid diversity, distribution, and research coverage in The Bahamas, a region internationally recognized for shark conservation but where batoids receive comparatively little attention. Species inventories were compiled from taxonomic references and global biodiversity databases, while research effort was assessed through a systematic review of peer-reviewed literature. In addition, records from the citizen science platform iNaturalist were analyzed to evaluate their contribution to documenting batoid occurrence. Twenty-eight species were identified as potentially occurring in Bahamian waters; however, only six species have been the subject of published research in the region. Research effort is strongly concentrated on shallow coastal habitats and a small number of accessible species, while deep-sea and pelagic batoids remain largely undocumented. Citizen science observations provided supplementary spatial information but did not substantially expand species representation. The analysis also revealed major thematic gaps, including limited information on fisheries interactions, tourism impacts, habitat degradation, and climate-related environmental change. Addressing these gaps through targeted surveys, collaborative monitoring frameworks, and integration of diverse data sources will be essential to support evidence-based conservation and management of batoid populations in The Bahamas.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"97 ","pages":"Article 105023"},"PeriodicalIF":2.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147850474","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":"Two islands, one ray: Age and growth pattern of the common eagle ray (Myliobatis aquila) in the Central Mediterranean (Sicily and Sardinia)","authors":"Andrea Bellodi ,&nbsp;Manfredi Madia ,&nbsp;Blondine Agus ,&nbsp;Pierluigi Carbonara ,&nbsp;Massimiliano Bottaro ,&nbsp;Mauro Sinopoli ,&nbsp;Maria Cristina Follesa","doi":"10.1016/j.rsma.2026.105029","DOIUrl":"10.1016/j.rsma.2026.105029","url":null,"abstract":"<div><div>The common eagle ray represents one of the most threatened batoid species inhabiting the Mediterranean Sea. Despite its low commercial value, the species is frequently encountered in both commercial and artisanal fishery bycatch. Nonetheless, the information available on its life history, especially its growth pattern, are rather scarce. Given the importance of growth data for accurately assessing the status of a species' population and informing its management, this study aims to provide new insights into the growth patterns of the common eagle ray in the western-central Mediterranean Sea. Between 2014 and 2024 a total of 200 vertebral centra were analysed from specimens caught along the coast of the two major Mediterranean islands (Sicily and Sardinia). Vertebrae were only extracted from specimens that were found to be already dead at the time of the capture, while live individuals have been released. To accurately describe the species' growth, different models were fitted to age-at-length data in a multi-model inference analysis. The von Bertalanffy growth function was indicated by the corrected Akaike’s Information Criterion as the most accurate in describing the species' growth. Results indicated that females reaching larger sizes (in disk width, DW) and greater longevity (DW: 189–737 mm; age range: 0–10 years) but growing at a slower rate (DW∞ = 872.9 mm; k = 0.11 y⁻¹; t₀ = −2.36) compared to males, which showed smaller maximum sizes and shorter lifespans (DW: 250–567 mm; age range: 0–7 years; DW∞ = 511.1 mm; k = 0.36 y⁻¹; t₀ = −1.36).</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"97 ","pages":"Article 105029"},"PeriodicalIF":2.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147850475","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":"CO2 fluxes in a recently restored salt marsh","authors":"Paula Warren-Jiménez ,&nbsp;Sofía Rodríguez-Gómez ,&nbsp;Jorge Juan Montes-Pérez ,&nbsp;Miriam Ruiz-Nieto ,&nbsp;Guillermo Ledesma-Hernández ,&nbsp;Teresa Gil-Gil ,&nbsp;Enrique Moreno-Ostos","doi":"10.1016/j.rsma.2026.105008","DOIUrl":"10.1016/j.rsma.2026.105008","url":null,"abstract":"<div><div>Blue carbon ecosystems are not only known to be one of the most important carbon sinks, but also their restoration is considered a nature-based tool for mitigating climate change impacts. Further research on restored salt marshes is essential to understand the recuperation of natural carbon dynamics and provide insights into short-term effects and a basis for long-term monitoring. In this study, we assess the net CO₂ exchange with the atmosphere over a year in a recently restored salt marsh in Trebujena, southern Spain. We measured CO₂ fluxes every two months from bare and vegetated sediments that were terrestrialised, under both dark and light conditions, and examined their relationships with the environmental variables measured <em>in situ</em> (i.e. sediment temperature, moisture, salinity, pH, organic carbon, and inorganic carbon). Additionally, CO₂ flux measurements were taken on the flooded area at the water-air interface. Our results indicate that CO₂ fluxes were significantly influenced by sediment temperature, moisture, and salinity. Bare and vegetated sediments were CO₂ sources because the meadow's uptake was insufficient to offset emissions from terrestrialised sediments, suggesting a degraded physiological state of the vegetation. In contrast, the flooded area was a net CO₂ sink, suggesting that the recovery of the natural hydrological regime would be advisable to promote the restoration of the carbon dynamics.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"97 ","pages":"Article 105008"},"PeriodicalIF":2.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147798239","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":"Accumulation and ecological risk of microplastics in sediments and mollusks in coastal areas along the Northern Vietnam","authors":"Do Thi Hien ,&nbsp;Trinh Thi Tham ,&nbsp;Tran Manh Tri ,&nbsp;Le Thanh Huyen ,&nbsp;Le Thi Trinh ,&nbsp;Pham Ba Viet Anh ,&nbsp;Trinh Thi Thuy ,&nbsp;Le Ngoc Thuan ,&nbsp;Vu Duc Nam ,&nbsp;Nguyen Cao Van ,&nbsp;Tu Binh Minh","doi":"10.1016/j.rsma.2026.105009","DOIUrl":"10.1016/j.rsma.2026.105009","url":null,"abstract":"<div><div>Microplastics (MPs) are a newly emerging persistent pollutant that requires attention to research regarding their distribution and accumulation in sediments, and especially in aquatic animals. Studies on MPs accumulation in sediments and benthic mollusks in the same area are limited. This study was conducted to investigate the abundance and characteristics of MPs in sediments and benthic mollusks in the Northern coastal region of Vietnam. The abundance of MPs in sediment and benthic mollusks was 1328 ± 404 items/kg d.w. and 4097 ± 2188 items/kg w.w., respectively. In both sediment and biota samples, MPs sizes of less than 1 mm were dominant, with more than 65%. The predominant shapes of MPs that were found in both sediment and mollusk samples were fragment (42% in sediment, 49% in mollusks), fiber (28% in sediment, 41% in mollusks), film, and bead. Black and blue-sky colored particles were mainly observed, while other colors were identified, for example, transparent, red, and yellow. Additionally, the Pollution Load Index (PLI) and the Polymer Hazard Index (PHI) also helped describe the pollution loading and potential hazards. The PLI calculated above is greater than 1, and PHI values ranging from 3.33 to 8.13 indicate a medium hazard at the study regions. The findings have highlighted the absolute necessity of creating effective plans for the control and reduction of pollutants originating from marine activities, as well as from inland areas discharged into the river.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"97 ","pages":"Article 105009"},"PeriodicalIF":2.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147798944","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 analysis of high chlorophyll episodes in the Mar Menor lagoon from an ocean color perspective","authors":"Francisco Gómez-Jakobsen ,&nbsp;Lidia Yebra ,&nbsp;Isabel Ferrera ,&nbsp;Juan M. Ruiz ,&nbsp;Jesús M. Mercado","doi":"10.1016/j.rsma.2026.105017","DOIUrl":"10.1016/j.rsma.2026.105017","url":null,"abstract":"<div><div>The <em>BELA</em> algorithm was specifically developed to estimate chlorophyll <em>a</em> concentrations from Ocean Color data in the Mar Menor, a hypersaline Mediterranean coastal lagoon that suffered a severe ecosystem disruptive algal bloom in 2015. Using this algorithm, five episodes of elevated chlorophyll concentrations were detected in the lagoon over the past two decades, with an increased presence since 2015. Analysis of these episodes revealed both similarities and differences in their timing and spatial distribution. Most episodes began in early summer, although their duration varied, lasting from 138 to 348 days. The highest chlorophyll concentrations were observed in the southern part of the lagoon, progressively extending northwestward in subsequent events. The two longest episodes exhibited bimodal patterns with two successive peaks. Spectral analysis revealed variations in phytoplankton communities and/or optical constituents, both across episodes and within individual events, over time and space. Non-hierarchical cluster analysis of satellite-derived reflectance spectra identified three distinct spectral variation modes during high chlorophyll periods, with the most notable differences observed in the blue spectral bands. These findings underscore the value of Ocean Color sensors for monitoring the Mar Menor coastal lagoon, providing a valuable complement to traditional in situ measurements.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"97 ","pages":"Article 105017"},"PeriodicalIF":2.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147850332","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":"Size-specific catch-per-unit-effort standardization and length-composition estimation for Japanese flounder (Paralichthys olivaceus) caught with gillnets off the northern coast of Kagoshima Prefecture","authors":"Takahito Masubuchi ,&nbsp;Naoto Yoshimura ,&nbsp;Yuma Yoshida","doi":"10.1016/j.rsma.2026.105006","DOIUrl":"10.1016/j.rsma.2026.105006","url":null,"abstract":"<div><div>The stock assessment of data-limited fisheries remains a global challenge, particularly in small-scale coastal fisheries. Japanese flounder (<em>Paralichthys olivaceus</em>) is an important species for coastal fisheries and has been caught using various fishing gears. Currently, stock assessments of this species are conducted in Japan using virtual population analysis (VPA). Size-structured abundance indices are fundamental inputs for age-structured stock assessment models, including VPA tuning and integrated models, such as Stock Synthesis. However, obtaining these data requires extensive biological sampling programs. We developed an analytical framework to derive size-structured catch-per-unit-effort (CPUE) indices from commercial market grading records and applied it to a Japanese flounder gill net fishery in Kagoshima Prefecture, Japan. We estimated CPUE indices for four size categories using Bayesian linear mixed models, accounting for temporal, spatial, and individual fisher effects. The framework addresses the challenge of varying grading standards among ports by calibrating port-specific size category–weight relationships. The results revealed divergent trends among size classes: the Small grade (predominantly age-1 fish) showed increasing abundance, whereas the Medium, Medium–Large, and Large grades remained relatively stable. The stable proportion of large fish (11% throughout the study period) suggests that this population maintained its age structure despite ongoing fishing pressure. This approach demonstrates that routinely collected market data can yield essential inputs for modern stock assessment models for data-limited fisheries worldwide.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"97 ","pages":"Article 105006"},"PeriodicalIF":2.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147850393","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":"Genetic connectivity of Uroteuthis sibogae (Cephalopoda: Loliginidae) in the Sulu Sea with notes on morphology and statolith microchemistry","authors":"Jessica M. Legaspi ,&nbsp;Lorenzo C. Halasan ,&nbsp;Kris Angeli Sanchez-DelosReyes ,&nbsp;Tomoyo Okumura ,&nbsp;Hsiu-Chin Lin","doi":"10.1016/j.rsma.2026.105019","DOIUrl":"10.1016/j.rsma.2026.105019","url":null,"abstract":"<div><div><em>Uroteuthis sibogae</em> is a neritic squid widely distributed in the Indo-Pacific and represents an important resource for both large and small-scale fisheries. In Southeast Asia, a region characterized by archipelagic complexity and high nearshore cephalopod diversity, its genetic structure remains poorly understood. This study examined the population connectivity of <em>U. sibogae</em> from the Sulu Sea and adjacent regions using mtDNA COI sequences. Results revealed a dominant single clade with a widely shared haplotype network (Hd = 0.7042 ± 0.0547; π = 0.0019 ± 0.0014), low genetic divergence (pairwise F_ST = 0.0256; %K2P = 0.1780%), high female-mediated gene flow (<em>N</em>_<em>f</em><em>m</em>_<em>f</em> = 14.52), and absence of population sub-structuring (AMOVA: F_ST = 0.0393; <em>p</em> = 0.0186). Historical analyses also indicated demographic expansion near the end of the Last Glacial Maximum, with a present-day effective population size (median <em>Ne</em> = 4.06E6) exceeding that of its sympatric relative <em>U. duvaucelii</em> (median <em>Ne</em> = 1.45E6). Morphometric comparisons showed high consistency with Indian and Taiwanese population records, though subtle differences in tentacle lengths were observed. We recommend combining arm III and tentacular sucker ring teeth characteristics with DNA barcoding to improve species diagnosis. Our subsampled individuals exhibited non-linear growth patterns consistent with power models, while statolith elemental ratios (Mg/Ca, Sr/Ca, Na/Ca) suggested that sub-adults to adults occupy a relatively stable thermal and salinity niche. These findings underscore the importance of integrated approaches to support conservation and sustainable management of the species and other valuable loliginids in the region.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"97 ","pages":"Article 105019"},"PeriodicalIF":2.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147850394","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":"Asymmetric marine heat wave patterns in the two basins of the North Indian Ocean","authors":"Alankita Nag ,&nbsp;Neethu Chacko ,&nbsp;Debadatta Swain ,&nbsp;K.K. Sandeep","doi":"10.1016/j.rsma.2026.105034","DOIUrl":"10.1016/j.rsma.2026.105034","url":null,"abstract":"<div><div>Marine heat waves (MHWs), which are characterized by prolonged periods of anomalously warmer seawater temperature, have been increasingly observed over the global oceans. In this study, we investigate the MHW activity in the Arabian Sea (AS) and Bay of Bengal (BoB) during the period 1982–2024, focusing on their contrasting features. Our results show collateral differences in the MHW activity in the two basins. Seasonal variability was distinctive, with the AS showing peak MHW occurrences in pre-monsoon, in contrast to post-monsoon events dominating the BoB. Most MHW events in the two basins were observed in the recent decades. We show that although MHWs are intensifying across both basins, the AS is experiencing a more pronounced strengthening in their intensity and persistence, whereas the BoB shows a relatively stronger rise in frequency. The trend of frequency and duration of MHW events in the AS (BoB) are 0.92/year (1.12/year) and 7.59 days/decade (5.60 days/decade), respectively, which also emphasizes the marked contrasts between the two basins. Further analysis revealed the MHWs to develop more rapidly in the BoB as compared to the AS. This study provides a comprehensive understanding of the contrasting features of the MHW activity, including the rate of onset and decline of MHW events in the two basins of the North Indian Ocean.</div></div>","PeriodicalId":21070,"journal":{"name":"Regional Studies in Marine Science","volume":"97 ","pages":"Article 105034"},"PeriodicalIF":2.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147850473","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}