Journal of Marine Systems最新文献

{"title":"A Bayesian approach to map oceanic structures, with an application to the Gulf Stream","authors":"Alessandro Comunian,&nbsp;Mauro Giudici,&nbsp;Arianna Panzeri","doi":"10.1016/j.jmarsys.2025.104175","DOIUrl":"10.1016/j.jmarsys.2025.104175","url":null,"abstract":"<div><div>A Bayesian approach is proposed to map position and evolution of oceanic structures. In the simplest formulation, the prior probability density function (PDF), i.e., the probability that a given point at a given time belongs to the considered structure, is modulated through the Bayes theorem by the likelihood and the marginal PDF. The likelihood represents the PDF of the observed data, conditioned on the fact that the examined point belongs to the structure at the examined time. The marginal PDF represents the probability of observing the field data, independently of the fact that the point belongs or not to the structure. A procedure to model prior PDF, likelihood and marginal PDF from observed data and to obtain the posterior PDF, namely the probability that a point belongs to the structure at a given time, conditioned on observed data, is proposed. The procedure is tested to map the Gulf Stream, based on observations of physical properties at the sea surface: temperature (SST), velocity (SSV) and salinity (SSS). The results of a single-variable model, based on SST only, are compared with those obtained from double-variable (SST and SSV) and multiple-variable (SST, SSV, SSS) models. The results show the relevance of data resolution and the importance of the proper modeling of the marginal PDF.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"253 ","pages":"Article 104175"},"PeriodicalIF":2.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145884436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Southern Ocean salp diel vertical migration and the significant influence of life cycle stage and body size","authors":"Alexis A. Bahl ,&nbsp;Florian Lüskow ,&nbsp;Moira Décima ,&nbsp;Deborah K. Steinberg ,&nbsp;Evgeny A. Pakhomov","doi":"10.1016/j.jmarsys.2025.104161","DOIUrl":"10.1016/j.jmarsys.2025.104161","url":null,"abstract":"<div><div>Diel vertical migration (DVM) is a widespread behavior among zooplankton and micronekton, playing a crucial role in carbon cycling by transporting organic matter to depth. The Southern Ocean salp, <em>Salpa thompsoni</em>, is an abundant gelatinous zooplankton species recognized for its significant contribution to vertical carbon export. It’s high grazing capacity, production of rapidly sinking fecal pellets, and extensive DVMs make it a key player in biogeochemical cycles. Despite its ecological importance, the influence of the life cycle stage and body size on <em>S. thompsoni</em>’s migratory behavior has been understudied. Utilizing net data from six Southern Ocean locations collected between 1989 and 2018, we provide stage- and size-specific vertical distribution and migration distance estimates, supported by circumpolar predictions using a mixed-effects modeling approach. Our results reveal that small-bodied, early developmental salps migrate amplitudes up to three times greater than their larger, reproductive counterparts, which tend to remain stationary or undergo reverse DVM. Environmental factors, such as salinity and euphotic zone depth strongly influence <em>S. thompsoni</em> DVM patterns, with the potential to impose as primary controls on the main hypothesized driver, reproduction. This first Southern Ocean-wide analysis of <em>S. thompsoni</em> DVM underscores the critical importance of incorporating life cycle stage and body size into assessments of salp behavior. Understanding these dynamics is essential for improving the estimated vertical carbon export via the migrant pump and refining global biogeochemical models.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"253 ","pages":"Article 104161"},"PeriodicalIF":2.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145797907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Frontlines of productivity: A remote sensing view into the seasonal mosaics of the Southwest Atlantic Ocean","authors":"Martín J. Rivarossa ,&nbsp;Valeria A. Guinder ,&nbsp;E. Marcelo Acha","doi":"10.1016/j.jmarsys.2025.104176","DOIUrl":"10.1016/j.jmarsys.2025.104176","url":null,"abstract":"<div><div>Frontal systems associated with continental shelf breaks rank among the most biologically productive marine environments, supporting rich food webs and key fisheries. In the Southwestern Atlantic, the Patagonian Shelf Break Front (PSBF; 35°S–55°S) is a globally significant hotspot of primary production, yet its spatial extent and seasonal variability remain poorly understood. Using a 20-year MODIS-Aqua chlorophyll-a (Chl-a) climatology, we delineated the productive region influenced by the PSBF – termed here the Chlorophyll Front - and analyzed its seasonal dynamics. Unsupervised k-means clustering of annual Chl-a cycles revealed five regions with distinct phytoplankton phenological patterns, organized along a latitudinal gradient. Phenological metrics at both region and pixel scales showed clear patterns in bloom initiation, intensity, and duration. Notably, a bimodal seasonal pattern - with spring and summer peaks - was observed in ∼60 % of the area. In most of the ecosystem, the cumulative duration of phytoplankton blooms throughout the phenological cycle exceeded 160 days per year, placing this ecosystem among those with the longest total bloom durations in the global ocean. Maximum annual Chl-a integration occurred in northern regions, aligning with the most dense benthic beds of the Patagonian scallop, a key fishery resource in the area. The spatial arrangements of key phenological metrics appears to be influenced by canonical environmental drivers such as seasonal light availability and water column stratification, while also reflecting influence of more stochastic forces like upwelling intensity and wind variability. The resulting bioregionalization and phenological metrics parametrization offer a robust framework to monitor change and inform spatially explicit management. By unveiling the structure and functioning of this globally relevant frontal system, our study provides critical baselines for understanding the vulnerability of oceanic fronts to climate change and anthropogenic pressures.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"253 ","pages":"Article 104176"},"PeriodicalIF":2.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145939026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Drastic changes in macrofaunal communities of intertidal boulder fields habitat during the last decade in the south of the Bay of Biscay","authors":"Léa Marmion ,&nbsp;Marie-Noëlle de Casamajor ,&nbsp;Muriel Lissardy ,&nbsp;Florian Ganthy ,&nbsp;Laura Huguenin ,&nbsp;Claire Kermorvant ,&nbsp;Yann Lalanne","doi":"10.1016/j.jmarsys.2025.104171","DOIUrl":"10.1016/j.jmarsys.2025.104171","url":null,"abstract":"<div><div>The cumulative effects of environmental and anthropogenic pressures on marine environments are endangering the biocenoses that inhabit them. Identifying and understanding the impacts of global changes are key challenges for maintaining habitats in a good ecological state and require the use of standardized monitoring and reliable ecological indicators.</div><div>During last decade, as part of various research programs, macrofaunal communities were inventoried in the boulder fields in the Southeastern Bay of Biscay, in an area devoid of fishing pressure. During two time periods, 2015-2016 and 2021-2022, mobile and sessile macrofauna of the upper and lower mediolittoral zones were sampled annually between April and June following a stratified random sampling design. The results reveal significant spatio-temporal changes over the study period, with a transitional year in 2020, that may be associated with the annual appearance of toxic blooms of the microalga <em>Ostreopsis</em>. Shifts in biodiversity, functional structure and the status of indicator species of the habitat were observed, with a marked decline or even local disappearance of several species. From a functional perspective, the decline in grazer abundance was striking particularly in the upper zone. While other guilds in the upper zone showed limited and non-significant changes, the lower zone revealed a broader and significant decline across multiple trophic groups, reflecting a more generalized functional reorganization and supporting the shift toward a new ecosystem state. This ecological shift appears to coincide with long-term changes in environmental parameters (e.g. water temperature, salinity) and may signal a transition toward a novel community state.</div><div>These results underscored the importance of ongoing monitoring for the management and conservation of coastal rocky habitats in the Southeastern Bay of Biscay. The findings highlight the capacity of this monitoring method to detect early signs of ecosystem change and reveal emerging stressors. The effect of the change and the transition to a new state on ecosystem functioning are discussed.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"253 ","pages":"Article 104171"},"PeriodicalIF":2.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145840536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatiotemporal patterns of marine heatwaves in the Southern Ocean and their role in air-sea interaction","authors":"K. Gurumoorthi,&nbsp;Alvarinho J. Luis","doi":"10.1016/j.jmarsys.2025.104141","DOIUrl":"10.1016/j.jmarsys.2025.104141","url":null,"abstract":"<div><div>Marine heatwaves (MHWs) are extended periods of abnormally warm ocean conditions in which temperature exceeds the 90th percentile threshold limit. While prior studies have mainly focused on regional trends, the Southern Ocean, particularly around Antarctica, has been relatively understudied despite experiencing considerable warming in recent decades. This study investigates MHWs in the Southern Ocean from 1982 to 2022, highlighting significant spatial and temporal variations in their frequency, intensity, and days. MHWs were found to be more frequent (0.4 events per decade) and intense north of 65°S, especially during the summer, with a marked rise in occurrence after 2008, coinciding with anthropogenic climate change and increasing sea surface temperatures (SST). The study also identifies the influence of climate patterns such as El Niño and the Indian Ocean Dipole (IOD) on MHWs intensity and frequency, particularly in the Ross Sea during spring and autumn. We analyzed the atmospheric impacts of significant MHWs in 2013. The 2013 MHW event serves as a key example of extreme subsurface warming, where temperatures reached 6.2 °C at 120 m depth, significantly increasing the region's heat content. This highlights how MHWs can transmit heat vertically, impacting both surface and deep ocean layers. The findings emphasize the complex interactions between ocean dynamics, and atmospheric conditions in determining MHWs patterns in the Southern Ocean, offering crucial insights for predicting the region's future responses to climate change.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"252 ","pages":"Article 104141"},"PeriodicalIF":2.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145227505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of winds and river discharge on the transport of microplastics in the world’s largest choked coastal lagoon (Patos Lagoon, Brazil)","authors":"Thais Teixeira Gava ,&nbsp;Pablo Dias da Silva ,&nbsp;Rémi Bouyssou ,&nbsp;Grasiela Pinho ,&nbsp;Elisa Fernandes","doi":"10.1016/j.jmarsys.2025.104154","DOIUrl":"10.1016/j.jmarsys.2025.104154","url":null,"abstract":"<div><div>Microplastics (MPs) contamination poses a significant environmental challenge in aquatic ecosystems, including coastal lagoons. This study investigates how variations in wind patterns and river discharge influence MP distribution in Patos Lagoon, the world’s largest coastal choked lagoon, located in southern Brazil. We employed the TELEMAC-3D hydrodynamic model and the TrackMPD particle tracking model to simulate MPs trajectories during high and low river discharge periods in the southern springs of 2009 and 2010. Results reveal notable differences in MP distribution between high and low discharge periods. During high discharge, prevailing northeasterly winds facilitated MP transport towards the ocean, whereas low discharge and southerly winds led to the concentrations of MPs near the release points. Most MPs (approximately 60%) were concentrated between the surface and 3 meters depth in both scenarios. In low discharge periods, 82.5% of MPs remained within the lagoon compared to 63.7% during high discharge. Accumulation areas varied significantly, with a predominance in ports, estuarine areas, and the northern and central cells during high discharge, and in the southern regions of the lagoon, near the release points, as well as in port and estuarine areas during low discharge. These findings are critical for understanding MPs dynamics in Patos Lagoon and for guiding tailored management and mitigation strategies. They underscore the importance of considering wind patterns and river discharge variations in defining effective management strategies.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"252 ","pages":"Article 104154"},"PeriodicalIF":2.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145578849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Physical and biogeochemical variability in the Gulf of La Spezia (Eastern Ligurian Sea, Italy): insights from a new high-resolution coastal observatory","authors":"Tiziana Ciuffardi ,&nbsp;Silvia Becagli ,&nbsp;Giancarlo Raiteri ,&nbsp;Andrea Bordone ,&nbsp;Erica Gabrielli ,&nbsp;Marcello G. Magaldi ,&nbsp;Andrea Peirano ,&nbsp;Fabio Piccolin ,&nbsp;Petrika Gjanci ,&nbsp;Chiara Petrioli ,&nbsp;Daniele Spaccini ,&nbsp;Marinella Abbate ,&nbsp;Ivo Rossetti ,&nbsp;Paolo Varrella ,&nbsp;Chiara Lombardi","doi":"10.1016/j.jmarsys.2025.104156","DOIUrl":"10.1016/j.jmarsys.2025.104156","url":null,"abstract":"<div><div>Coastal marine shallow sites exhibit high biological richness and diversity while experiencing substantial fluctuations in seawater physical and chemical variables. The complexity of coastal processes and dynamics, exacerbated by the climate change effects, are making difficult to predict the fate of marine coastal systems.</div><div>High-resolution observatories enable big data acquisition through continuous monitoring, improve the real-time detection of oceanic changes, especially at local scale, and provide essential data for marine system predictions and early warning capabilities for maritime activities. However, comprehensive long-term, high-resolution datasets in coastal areas are still limited.</div><div>Smart Bay Santa Teresa underwater observatory, a new high-resolution system located in the Eastern Ligurian Sea, provided physical and biogeochemical data continuously from 2021 to 2024. Physical data confirmed a warming trend of 0.045 °C per year in the study area, consistent with global climate change patterns, and increased frequency and intensity of Marine Heatwaves, especially in 2022–2023. Biogeochemical data revealed an enriched carbonate environment, despite the short-term perturbations, and a shift of biogenic and thermal control of the carbonate system through seasons favoring biogenic carbonate development (i.e. mussels' reefs). Interestingly, the balance between CO₂ stock and release, derived from biogenic calcification, revealed that the area as an active carbon sink, especially in winter and spring.</div><div>The ecological value and biodiversity of the coastal marine ecosystems coexisting with highly anthropogenic areas make the site ideal to monitor the interacting effects of global warming, local hydrodynamics, and seasonal biogeochemical processes through integrated monitoring approaches.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"252 ","pages":"Article 104156"},"PeriodicalIF":2.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145528518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamics of Total organic carbon: Partitioning, distribution and controlling processes in the Indian sector of the Southern Ocean during austral summer","authors":"Melena A. Soares,&nbsp;V. Venkataramana,&nbsp;R.K. Mishra,&nbsp;P. Sabu,&nbsp;R.K. Naik,&nbsp;Manish Tiwari,&nbsp;N. Anilkumar,&nbsp;R. Mohan,&nbsp;K. Mahalinganathan","doi":"10.1016/j.jmarsys.2025.104137","DOIUrl":"10.1016/j.jmarsys.2025.104137","url":null,"abstract":"<div><div>The Southern Ocean (SO) is a globally important region connecting the Pacific, Atlantic and Indian Oceans, having extreme seasonal changes and is crucial with regard to the carbon dynamics. Organic carbon plays a vital role in various biogeochemical processes and the carbon biological pump in the ocean. This study discusses the variability of total organic carbon (TOC) and its partitioning into particulate and dissolved fractions across the different fronts of the Indian sector of the Southern Ocean during two austral summers. A considerable interannual variation in the TOC distribution was noted, TOC concentration ranged from 84.4 to 127.8 μM in 2013 and from 76.3 to 121.2 μM in 2015, with considerable interannual variation in the TOC distribution. This study implied that the dominant phytoplankton community substantially contributed to the changes in composition and partitioning of organic carbon in the epipelagic waters and microbial respiration in the mesopelagic waters. Besides, the zooplankton community and its grazing effect influenced the organic carbon dynamics within the water column. Also, a significant correlation of total organic carbon with temperature, apparent oxygen utilisation and dissolved inorganic carbon, suggests the interplay of physical mixing processes like water mass intrusion and eddies. With biochemical responses altering the TOC distribution. Importantly, even small climate changes like warming in the SO can stimulate alterations in hydrographic processes, the food web structure and carbon pathways, impacting the fate of organic carbon in the oceanic ecosystem.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"252 ","pages":"Article 104137"},"PeriodicalIF":2.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145227506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A 125 years (1879–2003 CE) record of seasonal δ18O changes in a Porites lutea coral from the Lakshadweep Archipelago, southeastern Arabian Sea","authors":"Waseem Raza ,&nbsp;Syed Masood Ahmad ,&nbsp;Santosh Kumar Beja ,&nbsp;Chun-Yuan Huang ,&nbsp;Chuan-Chou Shen ,&nbsp;E.V.S.S.K. Babu","doi":"10.1016/j.jmarsys.2025.104142","DOIUrl":"10.1016/j.jmarsys.2025.104142","url":null,"abstract":"<div><div>We present a high-resolution δ¹⁸O record from two cores of living massive <em>Porites lutea</em>, covering a time period from 1879 to 2003 CE in the southeastern Arabian Sea to understand regional climate variability. The age models were established using annual banding counts and U-Th dating technique<em>.</em> Results show δ¹⁸O values range from −5.45 to −4.41 ‰ and feature a monthly-resolved, decreasing δ¹⁸O trend over the entire 125 years, coinciding with a gradual increase in instrumental SST record. A marked decreasing coral-δ¹⁸O pattern was noticed for more recent years, in agreement with published coral-δ¹⁸O records from the Indian Ocean, suggesting a rapid rate of warming. The most negative δ¹⁸O (for any given year) occurs during peak summer and the least negative δ¹⁸O during peak southwest (SW) monsoon times. The seasonal δ¹⁸O amplitude lies mostly ∼0.6–0.7 ‰, indicating a combined effect of decreased sea surface temperature (SST) and increased sea surface salinity (SSS) during the SW monsoon times. Ordinary least squares linear regressions (OLS) analysis performed using the coral-δ¹⁸O and Extended Reconstructed Sea Surface Temperature (ERSST) values for three distinct time periods (1879 to 1924, 1939 to 1958 and 1988 to 2003 CE) yield the following equations: δ¹⁸O = −0.24 (±0.01) × SST (°C) + 1.9 (±0.32), δ¹⁸O = −0.29 (±0.01) × SST (°C) + 3.5 (±0.48) and δ¹⁸O = −0.25 (±0.02) × SST (°C) + 2.4 (±0.63). The coral record is characterized by a stepwise decreasing δ¹⁸O pattern and a dampening of δ¹⁸O signal during strong El-Niño Southern Oscillations years.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"252 ","pages":"Article 104142"},"PeriodicalIF":2.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145332920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Risk analysis of invasive species by ballast water: Case study in the Port of Gijón, Bay of Biscay","authors":"Verónica Soto-López ,&nbsp;Deva Menendez-Teleña ,&nbsp;Eva Garcia-Vazquez ,&nbsp;Marlene Bartolomé","doi":"10.1016/j.jmarsys.2025.104148","DOIUrl":"10.1016/j.jmarsys.2025.104148","url":null,"abstract":"<div><div>Global transportation is increasing significantly, with maritime transport playing a central role in global trade, as approximately 90 % of goods are transported via sea routes. While ballast water is essential for maintaining ship stability and manoeuvrability, it also presents a major environmental risk due to its potential to unintentionally transport invasive species to new environments. If these species survive and establish in the recipient ecosystem, they may disrupt native communities, impact the economy, and pose threats to human health. Ships are therefore recognised as a primary vector for aquatic biological invasions, with the associated risk varying depending on the type and volume of ballast water carried.</div><div>This study aims to assess the risk of invasive species introduction via ballast water by analysing maritime traffic at the Port of Gijón over a 21-year period. Located in the Bay of Biscay, Gijón is particularly vulnerable to the ecological impacts of intensive maritime activity. Based on traffic data, we developed a semi-quantitative procedure to estimate the biological contamination risk posed by each vessel arriving at the port. The analysis identifies countries of origin associated with risk and, through the use of biological databases and an evaluation of environmental conditions for species survival, generates a risk map that categorizes potential invasive species.</div><div>The results suggest that vessels arriving from national ports pose the highest risk (40.59 %), followed by those from Portugal (10.48 %), the United Kingdom (8.89 %), and France (7.05 %). Based on traffic patterns, 23 potential invasive species were identified. Of these, 20 were categorized as high risk on the generated map, and 6 have already been confirmed as present in the study area.</div><div>A simple and easily replicable procedure is proposed, which port authorities can implement using only existing records of port entries and exits.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"252 ","pages":"Article 104148"},"PeriodicalIF":2.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145527967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}