Journal of Marine Systems最新文献

{"title":"Long-term changes in the deep chlorophyll maximum and primary production in the deep-water basin of the Black Sea","authors":"Sergey A. Mosharov ,&nbsp;Alexander S. Mikaelyan ,&nbsp;Alexandra V. Sergeeva ,&nbsp;Vladimir I. Gagarin","doi":"10.1016/j.jmarsys.2025.104169","DOIUrl":"10.1016/j.jmarsys.2025.104169","url":null,"abstract":"<div><div>Long-term changes in the deep chlorophyll maximum (DCM) and the depth-integrated primary production (PP) in the Black Sea deep basin from 1953 to 2021 were analysed. The changes were compared with alterations in water transparency, nitrate concentration in the deep maximum (NO₃-max), its depth and the intensity of winter convection affecting the nutrient supply in the upper layer through the year. A regression between the light attenuation coefficient and the Secchi disk depth was constructed based on field data obtained over the past two decades. The regression differed from that constructed using data before 1989. Both regressions were used to reconstruct long-term changes in the euphotic zone depth. Over 68 years, in the stratified period from April to October, it varied from 21 to 43 m. The annual mean DCM depth ranged from 18 to 55 m and was, in most cases, confined to a depth of 1–2 % of the surface photosynthetically available radiation. The long-term dynamics of annual means of DCM and PP DCM and PP generally corresponded to the change in NO₃-max. These variables were significantly correlated with NO₃-max, supporting the hypothesis that NO₃-max variations altered the nitrate gradient and, consequently, its upward flux into the photic zone, primarily consumed by DCM. At the same time, long-term changes in DCM and PP were also influenced by winter convection, affecting the nutrient supply in the upper layer and the macro-hydrodynamics of the Black Sea throughout the year. After a peak in eutrophication in the mid-1980s and a decline after the mid-1990s, NO₃-max began to rise again in the last decade, indicating a new increase in eutrophication. The increasing trends in NO₃-max and DCM and an increase in phytoplankton biomass, primarily due to diatoms, support this assumption.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"253 ","pages":"Article 104169"},"PeriodicalIF":2.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145797909","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":"Local wind and remote forcing effects on exchange flows at the entrance to a subtropical estuary","authors":"Juan Torres-Córdoba ,&nbsp;Jorge Armando Laurel-Castillo ,&nbsp;Arnoldo Valle-Levinson ,&nbsp;Maria F. Gastelu-Barcena","doi":"10.1016/j.jmarsys.2025.104170","DOIUrl":"10.1016/j.jmarsys.2025.104170","url":null,"abstract":"<div><div>This study investigates how local wind and remote forcing influence subtidal exchange flows at the entrance to a subtropical estuary, the Peace River estuary, Florida, being a case study. Moored acoustic Doppler current profiler (ADCP) measurements were analyzed in combination with Empirical Orthogonal Function (EOF) and wavelet coherence analysis to identify distinct circulation responses to these forcings. Local wind forcing produced bidirectional circulation characterized by surface flows aligned with the wind and bottom flows opposing it. In contrast, remote forcing, representing large-scale barotropic disturbances propagating from the coastal ocean, produced predominantly unidirectional flows. The first two EOF modes captured these responses, explaining over half of the subtidal flow variance (65 %). Wavelet coherence analysis revealed a temporal coupling between Mode 1 and local wind stress, and between Mode 2 and remotely driven volume transport. These findings are among the few observational efforts that support theoretical results for local wind and remote forcing on estuarine exchange flows. As such, they enhance our understanding of wind-driven flow processes in estuarine systems and the connectivity between estuarine and shelf circulation.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"253 ","pages":"Article 104170"},"PeriodicalIF":2.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145798346","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":"Impact of extreme weather events on pelagic cyanobacterial communities: an in situ mesocosm study in the Gulf of Finland","authors":"Mariano Santoro ,&nbsp;Mari Vanharanta ,&nbsp;Cristian Villena-Alemany ,&nbsp;Christiane Hassenrück ,&nbsp;Martin Hagemann ,&nbsp;Hans-Peter Grossart ,&nbsp;Kasia Piwosz ,&nbsp;Kristian Spilling ,&nbsp;Matthias Labrenz","doi":"10.1016/j.jmarsys.2025.104174","DOIUrl":"10.1016/j.jmarsys.2025.104174","url":null,"abstract":"<div><div>Cyanobacteria play a critical role in regulating carbon, nitrogen, and phosphorus cycles in the Baltic Sea, seasonally forming extensive blooms under nitrogen-limited conditions in summer. Understanding their responses to environmental disturbances is crucial in the Baltic Sea where increasing and persistent surface water temperature anomalies were observed over the past two decades. During a 17-day mesocosm experiment in the southwestern Finnish archipelago (Gulf of Finland) designed to investigate microbial community dynamics under varying nutrient conditions, the unexpected occurrence of a natural disturbance event created a unique opportunity to assess the effects of pronounced physical changes on cyanobacterial dynamics. The natural disturbance overshadowed the expected effects of the nutrient treatments, which was especially evident for cyanobacteria. The picocyanobacterium <em>Cyanobium</em> spp. emerged as the dominant species throughout the study, particularly following the occurrence of the near gale wind-driven rainfall, likely due to its adaptability to rapid environmental changes. Conversely, the filamentous cyanobacteria <em>Aphanizomenon</em> spp. and <em>Pseudoanabaena</em> spp. thrived under stable conditions. These findings highlight the resilience of picocyanobacteria to environmental fluctuations and their primary role in driving cyanobacterial community dynamics during summer in the Baltic Sea, where natural perturbations are expected to occur with increasing frequency due to climate change.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"253 ","pages":"Article 104174"},"PeriodicalIF":2.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145798345","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 cumulative pressures analysis approach to Good Environmental Status assessment at Central Cantabrian Sea","authors":"Ángela María Márquez-Reyes ,&nbsp;Ulla Fernandez-Arcaya ,&nbsp;Antonio Punzón","doi":"10.1016/j.jmarsys.2026.104179","DOIUrl":"10.1016/j.jmarsys.2026.104179","url":null,"abstract":"<div><div>One of the objectives of the Marine Strategy Framework Directive (MSFD) is to identify, assess, and reduce the cumulative physical pressures on the seafloor to achieve Good Environmental Status (GES). This study aims to characterise the human activities that physically affect seabed integrity and to provide a first integrated assessment of the pressure accumulation in the Central Cantabrian Sea. To this end, spatial data on human activities, their associated seabed pressures, areas of influence, and interactions with benthic habitats were integrated into a unified 0.01° x 0.01° grid to enable cumulative pressure analysis. The results indicate that the Central Cantabrian Sea is intensively pressured: 8.4% of the assessed grid cells are classified as physically lost, while 40.8% are physically disturbed. Activity accumulation occurred mostly along infralittoral habitats, where rocky habitats present experience a high degree of spatial overlap with multiple stressors.</div><div>The main source of pressure accumulation arises from the interaction of different bottom contact fishing gears operating along deeper continental shelf and slope (113–644 m depth). In shallower infralittoral zones additional activities such as aquaculture and dredging contribute to the cumulative impact. The Site of Community Importance (SCI) Avilés Canyon System area also showed a high accumulation with up to 3–4 activities per grid cell, mostly related to fisheries. This work provides a methodological basis for assessing cumulative seabed activities causing disturbance and supports the development of spatial management strategies aligned with the objectives of the MSFD.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"253 ","pages":"Article 104179"},"PeriodicalIF":2.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145976650","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":"Identifying potential spawning sites and factors underlying the habitat selection of Indian Scad, Decapterus russelli, in the south eastern Arabian Sea during non-summer monsoon periods","authors":"Kusum Komal Karati ,&nbsp;G. Sreerenjima ,&nbsp;Sonal Rajendra Kalbande ,&nbsp;Ajit Antony","doi":"10.1016/j.jmarsys.2026.104186","DOIUrl":"10.1016/j.jmarsys.2026.104186","url":null,"abstract":"<div><div>The spawning period and the environment in which the eggs are released are critical in the reproductive success of fishes, and hence studies pertaining to these aspects have garnered wide research interest. The Indian scad, (<em>Decapterus russelli</em>) is one major carangid species that contributes significantly to the marine capture fishery of India. However, limited knowledge of their spawning period and habitat selection constrains formulation of management policies aimed at their sustainable fishery in this region. In the northern Indian Ocean, information on spawning grounds and the peak spawning period of this important species are mostly limited to the summer monsoon period. Thus, the present study specifically aimed to identify their potential spawning sites in the southeastern Arabian Sea during three non-summer monsoon periods (fall, winter and spring seasons). Continuous Underway Fish Egg Sampler (CUFES), an instrument specifically designed for fish egg sampling, was deployed for the first time in this region for effective sampling of fish eggs. Though <em>D. russelli</em> were observed to spawn during all three sampling periods, egg abundance was highest in the winter monsoon period when compared to the other non-summer monsoon periods in the southeastern Arabian Sea. Seasonal variation in abiotic and biotic factors in SEAS had a prominent influence on the spawning habitat selection of <em>D. russelli</em>. The abiotic and biotic variables, which were found to have an important role in the spawning habitat selection, had varying effects along different seasons depending on the closeness of their existing values towards the optimal condition.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"253 ","pages":"Article 104186"},"PeriodicalIF":2.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146090251","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 case study on tropical cyclone Oma-induced phytoplankton bloom in eastern Australia","authors":"Yuxia Liu ,&nbsp;Ye Wan ,&nbsp;Ziqiong Cheng ,&nbsp;Rufa'i Isyaku ,&nbsp;Haibin Lü","doi":"10.1016/j.jmarsys.2025.104178","DOIUrl":"10.1016/j.jmarsys.2025.104178","url":null,"abstract":"<div><div>In February 2019, a significant phytoplankton bloom occurred in the eastern Australian waters following Tropical Cyclone (TC) Oma. This study presents a comprehensive analysis of the upper ocean's ecological response to the TC, utilizing remote sensing data, reanalysis data, and Argo float observations. The results revealed that a clockwise-rotating eddy with a vorticity of up to 0.25 s⁻¹ formed in the area impacted by the TC. At the center of the eddy, the Chl-a concentration rose significantly to 0.2 mg·m⁻³.This highlights the eddy's key role in facilitating phytoplankton growth. Observations after the cyclone showed a deepening of the mixed layer, weakening of the thermocline, and thinning of the barrier layer. These changes collectively enhance the transport of deep-layer nutrients to the surface layer for phytoplankton growth. Furthermore, photosynthetically active radiation (PAR) in the eddy's region rose significantly to 60 Einstein·m⁻²·day⁻¹ after February 21, remaining high and creating optimal light conditions for the Chl-a bloom in the study region. The study can improve our understanding of the interactions between TCs and marine ecosystems in Eastern Australia.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"253 ","pages":"Article 104178"},"PeriodicalIF":2.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145939028","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":"Modelling the accumulation of 137Cs by Atlantic bluefin tuna (Thunnus thynnus) after a hypothetical nuclear accident in the Northwest Atlantic Ocean","authors":"Carmen Cortés ,&nbsp;Raúl Periáñez ,&nbsp;Barbara A. Block ,&nbsp;Michael R. Castleton ,&nbsp;Pablo Cermeño ,&nbsp;Simon Dedman","doi":"10.1016/j.jmarsys.2026.104180","DOIUrl":"10.1016/j.jmarsys.2026.104180","url":null,"abstract":"<div><div>The potential accumulation of radionuclides in migratory fish following nuclear accidents is a concern for marine ecology and human consumption. We developed and applied a Lagrangian numerical model coupled with a four-level food web uptake module to simulate the transport and bioaccumulation of ¹³⁷Cs in Atlantic bluefin tuna (<em>Thunnus thynnus</em>) in the Northwest Atlantic Ocean, following hypothetical Fukushima-like releases from three coastal nuclear power plants in eastern North America. Tuna trajectories were obtained from electronic tagging data, and ¹³⁷Cs transfers from water and prey were modelled daily at each tuna location. Simulations show that even when tuna pass through contaminated water and food patches, the resulting ¹³⁷Cs concentrations in their flesh remain low, with maximum values around 1 Bq/kg wet weight. These concentrations are well below international safety limits and often below typical background levels. The study confirms that the rapid movement of migratory species limits radionuclide uptake, suggesting that tuna consumption would remain safe even in the event of such accidents.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"253 ","pages":"Article 104180"},"PeriodicalIF":2.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038077","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":"Northernmost record in the Bay of Biscay (northeastern Atlantic) of two leptothecate hydroids (Cnidaria: Hydrozoa) of southern affinity","authors":"Álvaro Altuna ,&nbsp;Marie-Noëlle de Casamajor ,&nbsp;Ana de la Torriente ,&nbsp;Stephane Sartoretto ,&nbsp;Benoit Gouillieux ,&nbsp;Alberto Serrano","doi":"10.1016/j.jmarsys.2025.104158","DOIUrl":"10.1016/j.jmarsys.2025.104158","url":null,"abstract":"<div><div>Two leptothecate hydroids of southern affinity, <em>Sertularella ornata</em> <span><span>Broch, 1933</span></span> and <em>Sertularelloides cylindritheca</em> (<span><span>Allman, 1888</span></span>) were collected in the southern sector of the Bay of Biscay off Saint Jean de Luz (France). The latter was also seen during several ROV surveys on rocky communities along the Cantabrian Sea and northwestern Spain. Each of the two species is herein described and illustrated and their worldwide distribution, bathymetric ranges and reproductive periods, revised; additionally, we allocate them in their biocoenological context, providing in situ images. The northern boundary limits are extended for both hydroids, which are new records for the Atlantic coast of France; the latter belongs to a genus previously unrecorded in the French mainland fauna. We also discuss the importance of having inventories of the sessile fauna of the exceptional sites at study, for the sake of their protection and detection of future modifications due to climate change.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"253 ","pages":"Article 104158"},"PeriodicalIF":2.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145658443","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":"Water mass influence on the distribution of larval mesopelagic fish (Sternoptychidae) in the South Brazil Bight (23°S-28°S)","authors":"Gabriel Vilanova,&nbsp;Maria de Lourdes Zani-Teixeira,&nbsp;Mario Katsuragawa,&nbsp;Ulisses Cavalcante dos Santos,&nbsp;Marcelo Dottori,&nbsp;Danilo Augusto Silva,&nbsp;Ilson Carlos Almeida da Silveira,&nbsp;João Pedro Mancio de Amorim,&nbsp;Frederico Pereira Brandini,&nbsp;Cláudia Namiki","doi":"10.1016/j.jmarsys.2026.104185","DOIUrl":"10.1016/j.jmarsys.2026.104185","url":null,"abstract":"<div><div>Sternoptychidae (hatchetfishes and relatives) are among the most abundant mesopelagic fishes, playing important ecological roles in oceanic ecosystems. Their larvae are a frequent component of ichthyoplankton assemblages, although little is known about their early life stages in the South Brazil Bight (SBB). The present study aimed to analyze the distribution patterns of Sternoptychidae larvae in relation to water mass dynamics in the SBB, a region of intense mesoscale activity. Ichthyoplankton was collected during 2019 austral winter-spring and 2021–2022 summer, using a Multi Plankton Sampler from the surface to 2300 m. <em>Maurolicus stehmanni</em> (pearlside) was the most abundant among the six taxa identified. Most taxa were restricted to slope waters and larvae were recorded on the shelf in association with South Atlantic Central Water (SACW) intrusion. This cross-shelf interaction enables pearlside larvae to be transported onshore and use the shelf as nursery areas. SACW intrusion also broadened <em>Argyropelecus</em> spp. and <em>Valenciennellus tripunctulatus</em> known distributions to include the shelf. Larvae displayed vertical habitat partitioning of the water column, although taxa were mostly associated with SACW. Pearlside larvae presented a preferential vertical position in the Tropical Water-South Atlantic Central Water mixture, suggesting possible feeding areas and retention processes. This study was the first to describe vertical distribution patterns of sternoptychid larvae off the SBB and showed the significance of ichthyoplankton collection in deep waters, which allowed the sampling of rare species, including the first occurrence of larval <em>V. tripunctulatus</em> in the SBB. Stratified sampling was of utmost importance to understand species distribution in relation to the water masses and fronts.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"253 ","pages":"Article 104185"},"PeriodicalIF":2.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146090248","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":"Response of ocean surface currents to the summer monsoon onset in the northern Indian Ocean","authors":"Yue Yin ,&nbsp;Kuiping Li","doi":"10.1016/j.jmarsys.2025.104172","DOIUrl":"10.1016/j.jmarsys.2025.104172","url":null,"abstract":"<div><div>The surface currents in the northern Indian Ocean (IO) are profoundly influenced by the monsoon cycle. However, the systematic response of these currents to the abrupt onset of the summer monsoon remains insufficiently understood. Based on a surface current model, this study examines the evolution and dynamics of surface currents in relation to the climatological two-step monsoon onset in the northern IO. During the Bay of Bengal (BoB) monsoon onset, strong equatorial westerlies trigger downwelling equatorial Kelvin waves, which drive the spring Wyrtki Jet (WJ) to its peak phase. Simultaneously, intensified southwest winds south of Sri Lanka establish the Southwest Monsoon Current (SMC). As the equatorial Kelvin waves reach the eastern boundary, they give rise to westward-propagating Rossby waves, which further strengthen the current when traveling across the SMC region. Part of the equatorial Kelvin wave energy is converted into coastal Kelvin waves that propagate along the inner boundary of the BoB, leading to the weakening of the East Indian Coastal Current (EICC). The poleward Somali Current (SC) strengthens quickly during the BoB monsoon onset and intensifies further with the Arabian Sea (AS) monsoon onset, which is primarily driven by local wind forcing associated with both onset processes. The Great Whirl (GW) forms during the AS monsoon onset, coinciding with the second intensification of the SC. Local wind forcing also plays a crucial role in strengthening the GW after the AS monsoon onset. Understanding the response patterns and physical mechanisms of surface currents during the summer monsoon onset enhances our knowledge of monsoon-ocean interactions in the IO.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"253 ","pages":"Article 104172"},"PeriodicalIF":2.5,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145797908","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}