Progress in Oceanography最新文献

{"title":"Black coral and gorgonian assemblages of Santo Antão (Cabo Verde): diversity, distribution, and demographic structure","authors":"Teresa Amaro ,&nbsp;Daniel Gómez-Gras ,&nbsp;Tristan Ornelas ,&nbsp;Andrea Gori ,&nbsp;Núria Viladrich ,&nbsp;Jean-Baptiste Ledoux ,&nbsp;Cristina Linares","doi":"10.1016/j.pocean.2025.103527","DOIUrl":"10.1016/j.pocean.2025.103527","url":null,"abstract":"<div><div>Black coral and gorgonian assemblages are vital components of marine ecosytems, providing complex habitats that support high biodiversity. Despite their importance, these coral communities remain underexplored in the Cabo Verde Archipelago, a region of significant ecological value. This study provides the first systematic assessment of black coral and gorgonian assemblages in Santo Antão, examining their distribution, density, size structure, and morpho-functional traits through <em>in situ</em> surveys.</div><div>Our findings identified 11 species of black corals and gorgonians,and three key patterns: (1) Coral assemblages in Santo Antão are divided into black coral-dominated, gorgonian-dominated, and mixed assemblages with high diversity, particularly in the Northeast (NE) and Southeast (SE) regions. (2) Large, bushy and/or unbranched erect black corals thrived in high-current environments, whereas large, planar gorgonians flourished in gentler hydrodynamic conditions. Notably, mean (± SD) densities of black corals, such as<!--> <em>Stichopathes luetkeni</em> <!-->Brook, 1889 (46.0 ± 50.5 colonies/m²) and<!--> <em>Tanacetipathes spinescens</em> <!-->Gray, 1857 (23.2 ± 15.5 colonies/m²), were among the highest reported globally. Gates of Eden (SE) emerged as the most coral-abundant location. (3) Functional richness (FRic) varied across locations, with distinct spatial patterns observed at Hanging Garden Flat (SE) and Cruzinha hotel (NW).Overall, the observed patterns in taxonomic (species richness, evenness, and Shannon-Wiener) and functional diversity (FRic) reinforce the presence of distinct assemblages across Santo Antão: high-diversity hotspots in the NE and SE regions, low-diversity communities dominated by a few species and traits in the NW, and variable patterns in the SW and S regions.</div><div>This study establishes a crucial baseline for the diversity and ecological role of blackcoral and gorgonians in Santo AntãoOur findings underscorethe need for target conservation strategies, including the establishment of marine protected areas (MPAs)regulatory measures and community-based conservation initiatives to safeguard these vital ecosystems.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"237 ","pages":"Article 103527"},"PeriodicalIF":3.8,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144503689","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":"Basin-scale zooplankton composition in the Eastern Subarctic Pacific in the winter-spring","authors":"Joanne K. Breckenridge ,&nbsp;Evgeny A. Pakhomov ,&nbsp;Brian P.V. Hunt ,&nbsp;Alexei I. Pinchuk ,&nbsp;Moira Galbraith","doi":"10.1016/j.pocean.2025.103526","DOIUrl":"10.1016/j.pocean.2025.103526","url":null,"abstract":"<div><div>Knowledge of zooplankton distributions in the Eastern Subarctic Pacific (ESP) is limited and hinders our ability to assess ecosystem level change. To provide baseline information and increase our understanding of zooplankton ecology in the ESP, large-scale winter to early spring epipelagic zooplankton dynamics were investigated as part of three expeditions. Bongo tows (0.6-m mouth diameter, 250 µm mesh) were collected in 2019 (19 February – 15 March) and 2020 (12 March – 4 April) north of 47.5°N and east of 147.5°W and during a third survey in 2022 (6 February – 17 April), which expanded coverage westward to 172°W. General Additive Models identified a region of low zooplankton abundance and low biomass of small zooplankton in the Alaska Gyre. Cluster analysis of genus abundances separated samples largely along a temperature gradient. Clusters were broadly grouped into cool (&lt;7 °C) and warm (&gt;7 °C) assemblages. Cool assemblage clusters were dominated by subarctic taxa and their composition suggested a broad coherence in zooplankton structure north of the bifurcation of the North Pacific Current (NPC), with variation driven by the circulation of the gyre and inputs from neighbouring current systems. Warm assemblage clusters were primarily associated with the NPC bifurcation and were characterized by a mix of Subarctic, California Current, and Transition Zone taxa. Differences in species composition and biomass across the Alaska Gyre and between the northern ESP and the NPC bifurcation, including increased biomass of small zooplankton associated with the bifurcation, give insight into the foraging landscape that supports planktivores in the ESP.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"237 ","pages":"Article 103526"},"PeriodicalIF":3.8,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144501273","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":"Evaluating the performance of an ensemble forecast system in predicting Loop Current Eddy separation in the Gulf of Mexico","authors":"Prasad G. Thoppil ,&nbsp;Clark D. Rowley ,&nbsp;Patrick J. Hogan ,&nbsp;James Stear","doi":"10.1016/j.pocean.2025.103529","DOIUrl":"10.1016/j.pocean.2025.103529","url":null,"abstract":"<div><div>Forecasting mesoscale variability, such as the Loop Current (LC) growth and Loop Current Eddy (LCE) shedding in the Gulf of Mexico, poses challenges due to the large uncertainty in initial conditions and the development of non-linear instabilities from LC-cyclone interactions, which are crucial for LC/LCE separation. An ensemble forecast system may account for this uncertainty and filter out unconstrained scales and thereby extend the predictability of the mesoscale variability. A 32-member ensemble forecast system is employed to investigate the predictability of LC/LCE separation, with a specific focus on the December 2019 – March 2020 period. The forecasts demonstrated predictability of LC/LCE separation out to 7 to 13 weeks. During this period, significant changes occurred in the LC. The LC transitioned from being an extended LC to LCE separation on January 27, 2020. Subsequently, in March 2020, the LCE deformed and nearly split into two separate eddies. Detailed analyses of individual forecasts during this timeframe revealed that these transformations were influenced by two main interactions: (a) the interaction between the LC and a cyclone along its eastern edge, which caused the LC/LCE separation, and (b) the interaction between the LCE and a cyclone along its northern side, leading to the potential splitting of the LCE. These interactions were further intensified by the coupling between surface and deep cyclones. The validity of these findings is supported by a variety of observations, including drifters, current meters, and sea surface height, as well as verifying analysis.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"237 ","pages":"Article 103529"},"PeriodicalIF":3.8,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144503991","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":"Mechanisms controlling the seasonality and formation of subsurface chlorophyll maximum and oxygen-depleted waters in the east-central equatorial Indian Ocean","authors":"R. Prasanth ,&nbsp;Madhusudan Paul ,&nbsp;Trishneeta Bhattacharya ,&nbsp;Kunal Chakraborty ,&nbsp;Sandip Kumar Mukhopadhyay","doi":"10.1016/j.pocean.2025.103524","DOIUrl":"10.1016/j.pocean.2025.103524","url":null,"abstract":"<div><div>The time-series observations of temperature, salinity, chlorophyll-a (chl-a), particle back scattering at 700 nm (b<span><math><msub><mrow></mrow><mrow><mtext>bp</mtext></mrow></msub></math></span>) and dissolved oxygen (DO) obtained from 2029 profiles of eleven autonomous biogeochemical (BGC) Argo profiling floats deployed in the east-central Equatorial Indian Ocean (EEIO) have been used to study the seasonal variability of chl-a and DO across the water column and to identify the mechanisms governing their variability. EEIO experiences surface oligotrophic condition throughout the year and exhibit a strong (<span><math><mo>∼</mo></math></span> 0.8 mg m⁻³) subsurface chlorophyll maximum (SCM) except during summer monsoon when chl-a concentration at SCM is weak (<span><math><mo>∼</mo></math></span> 0.65 mg m⁻³). The SCM is a persistent feature of the EEIO occurring at around 60 m. Similar to chl-a, the concentration of b<span><math><msub><mrow></mrow><mrow><mtext>bp</mtext></mrow></msub></math></span> is low within the mixed layer, while maximum values are associated with the SCM. A coupled ocean-ecosystem model was employed to investigate nitrification, the uptake of nitrate (NO<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>) by phytoplankton (uptake), and the physical processes that maintain the availability of NO<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> in the SCM region. We find that, among the biological processes, uptake dominates over nitrification in the SCM, as nitrification is inhibited by surface light, and the nitrification maximum occurs just below the SCM. The NO<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> budget analysis also revealed that vertical advection from the nitrification maximum facilitates the availability of NO<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> in the SCM region. Further, the vertical distribution of DO shows a narrow DO-depleted region in the upper 200 m of the water column between the depth of 100–200 m, which lies just below the Arabian Sea High Salinity Water and another wider and deep DO-depleted region between the 600–1200 m depth. The upper narrow DO-depleted water, driven by volume transport across 4°N, extends southward from the Bay of Bengal, reaching its maximum extent during January–February and August.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"237 ","pages":"Article 103524"},"PeriodicalIF":3.8,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144480958","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":"Seasonal variability in surface water pCO2 and air-sea CO2 fluxes in the Northwestern Pacific Ocean","authors":"Yi Yang,&nbsp;Xianghui Guo,&nbsp;Dongjian Ci,&nbsp;Yi Xu,&nbsp;Yan Li,&nbsp;Liguo Guo,&nbsp;Minhan Dai","doi":"10.1016/j.pocean.2025.103515","DOIUrl":"10.1016/j.pocean.2025.103515","url":null,"abstract":"<div><div>The Northwestern Pacific Ocean is one of the most important carbon sink regions globally. However, spatial variability and seasonal amplitude of surface water CO₂ partial pressure (<em>p</em>CO₂) and air-sea CO₂ fluxes remain unresolved. Surface seawater <em>p</em>CO₂ and auxiliary parameters were investigated in the Northwestern Pacific (10–33°N, 120–158°E) during spring, summer and winter in 2019 and 2020. The air-sea CO₂ fluxes exhibited pronounced seasonal variability, acting as a CO₂ sink of 5.0 ± 4.1 mmol m⁻² d⁻¹ in winter and a CO₂ source of 1.7 ± 1.6 mmol m⁻² d⁻¹ in summer. In summer, the CO₂ source increased with latitude, with the 10–14°N sub-region near equilibrium with the atmosphere (0.6 ± 0.6 mmol m⁻² d⁻¹) and the 27–33°N sub-region displaying the strongest source (3.6 ± 2.1 mmol m⁻² d⁻¹). The air-sea CO₂ flux is primarily driven by variability in surface water <em>p</em>CO₂. During summer, surface water <em>p</em>CO₂ increases with latitude (408.4 ± 5.1, 418.2 ± 9.0 and 455.5 ± 12.4 μatm in 10–14°N, 14–27°N and 27–33°N, respectively), showing a “strange” pattern inverse with sea surface temperature. Temperature normalized <em>p</em>CO₂ (N<em>p</em>CO₂) also increases with latitude. In winter, surface water <em>p</em>CO₂ generally decreases with latitude (379.4 ± 3.8, 372.9 ± 9.1 and 354.5 ± 3.6 μatm in 10–14°N, 14–27°N and 27–33°N, respectively), but N<em>p</em>CO₂ increased with latitude (356.7 ± 7.7, 387.2 ± 13.1 and 434.4 ± 4.4 μatm in 10–14°N, 14–27°N and 27–33°N, respectively). In addition to the dominating temperature effect, different sub-regions have their own unique processes that affect the <em>p</em>CO₂ behavior which in turn influences the air-sea CO₂ fluxes. In the western zone (west of 130°E) of the 10-14°N sub-region, precipitation reduces <em>p</em>CO₂ by 12.4 ± 5.2 μatm in summer and 14.8 ± 4.4 μatm in winter. In the 14-27°N sub-region, the relatively high N<em>p</em>CO₂ is primarily driven by evaporation, with elevated salinity increasing surface water N<em>p</em>CO₂ by 11.1 ± 12.7 μatm in summer and 7.7 ± 15.3 μatm in winter. The 27–33°N sub-region is located in the Subtropical Mode Water and atmospheric CO₂ intrusion (increasing <em>p</em>CO₂ by 44.2 μatm) also have important contributions to the high N<em>p</em>CO₂. Under the context of global warming, the regional changes, such as variations in evaporation and precipitation, have the potential to significantly alter global ocean CO₂ sink/source patterns and weaken the surface ocean’s CO₂ sequestration ability.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"237 ","pages":"Article 103515"},"PeriodicalIF":3.8,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144331274","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":"Effects of the Kuroshio Extension jet and pinch-off ring on epipelagic mesozooplankton","authors":"Ruping Ge ,&nbsp;Hongju Chen ,&nbsp;Yueqi Zhang ,&nbsp;Zhaohui Chen ,&nbsp;Facan Lei ,&nbsp;Weimin Wang ,&nbsp;Yunyun Zhuang ,&nbsp;Guangxing Liu","doi":"10.1016/j.pocean.2025.103523","DOIUrl":"10.1016/j.pocean.2025.103523","url":null,"abstract":"<div><div>The eastward flow of the Kuroshio Extension (KE) is accompanied by intense eddy activities at both the mesoscale and submesoscale levels, exerting a substantial effect on biogeochemical processes in the upper ocean. The present study focused on how the KE jet and pinch-off cyclonic eddy influenced mesozooplankton community structure and functional traits in the northwestern Pacific. The zooplankton communities in the investigated regions formed a four-segment pattern from north to south, with significant differences in the species and functional trait compositions of each group. The KE stream acted as a barrier that prevented water exchange between the Kuroshio-Oyashio mixed water (KOMW) and North Pacific Subtropical Gyre (NPSG) regions. A comparatively higher proportion of current–feeding omnivore–herbivore zooplankton was recorded in the NPSG region when compared to the KOMW and KE regions, which can be attributed to the influence of the pinch-off cyclonic eddy. Red <em>Noctiluca scintillans</em> was carried from the coast of Japan to open water by the KE’s eastward advection, and it bloomed (1.2 × 10⁴ ind·m⁻³) in the KOMW under favorable hydrological and nutritional environments, changing the community structure of zooplankton. The pinch-off cyclonic eddy could increase zooplankton abundance but had no significant impact on species composition and functional traits. In addition, the divergence effect of the eddy resulted in greater zooplankton abundance at its edges than in the center. This study enhanced our knowledge of the impacts of the KE on zooplankton communities and has significant implications for understanding pelagic plankton and nutrient responses to pinch-off mesoscale eddies.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"237 ","pages":"Article 103523"},"PeriodicalIF":3.8,"publicationDate":"2025-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144289809","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 time series of water mass transports through the Balearic Channels using an ocean circulation inverse method: 1996–2022","authors":"Manuel Vargas-Yáñez ,&nbsp;Maxandre Ouradou ,&nbsp;Francina Moya ,&nbsp;Enrique Ballesteros ,&nbsp;Cristina Alonso ,&nbsp;Mariano Serra ,&nbsp;Safo Piñeiro ,&nbsp;Vicenç Moltó ,&nbsp;Rocío Santiago ,&nbsp;Rosa Balbín ,&nbsp;Silvia Sánchez-Aguado ,&nbsp;Mª Carmen García-Martínez ,&nbsp;Gabriel Jordà ,&nbsp;Alonso Hernández-Guerra","doi":"10.1016/j.pocean.2025.103525","DOIUrl":"10.1016/j.pocean.2025.103525","url":null,"abstract":"<div><div>Time series of temperature and salinity from CTD (Conductivity Temperature Depth) sections in the Ibiza and Mallorca Channels from 1996 to 2022 are used to calculate a time series of transports of Atlantic Water (AW), Western Intermediate Water (WIW), Levantine Intermediate Water (LIW) and Western Mediterranean Deep Water (WMDW). The oceanographic stations were distributed on two triangular closed boxes for the application of inverse circulation modelling. A data set of 80 oceanographic campaigns was initially considered. After examination and interpolation of the data, only 23 campaigns contained the complete sections forming the two boxes and were suitable for the calculation of transports using the inverse method. Over the course of 42 oceanographic cruises, only the southern sections of the Ibiza and Mallorca Channels were completed. In these cases, transports were derived from geostrophic velocities, using the sea floor as a reference level of no motion, and without employing the inverse method. The results from both methodologies showed a prevailing southward annual transport of the upper layer (AW + WIW) ranging between −0.1 Sv and −0.21 Sv in the Ibiza Channel and a northward transport between 0.07 Sv and 0.09 Sv in the Mallorca Channel (depending on the methodology used). A subjective classification of the circulation patterns for each individual campaign revealed the existence of 5 circulation modes: Northern Current mode, inflow mode, two-way circulation, reversed two-way circulation, and eddy circulation mode. The two-way circulation mode, with a southward flow at the western side of both channels and a northward flow at the eastern sides, was the most frequently observed circulation pattern. However, the inter-annual variability seems to be larger than the seasonal signal and it was very difficult to establish a seasonality in the occurrence of these circulation modes. LIW flows to the south in the Ibiza Channel and to the north in the Mallorca one, but the transports of this water mass were very low, suggesting that the main path of LIW follows the northern slope of the Islands, within the North Balearic Current. These results are used to speculate about the circulation and mass budget in the Northwestern Mediterranean.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"237 ","pages":"Article 103525"},"PeriodicalIF":3.8,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144289810","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":"Iron fertilization from Asian dust drives tertiary-level productivity of Pacific salmon","authors":"Yongsong Qiu","doi":"10.1016/j.pocean.2025.103514","DOIUrl":"10.1016/j.pocean.2025.103514","url":null,"abstract":"<div><div>Iron enrichment in high-macronutrient, low-chlorophyll surface oceans was hypothesized to enhance primary production and carbon sinks that ultimately influence the earth’s climatic system. Although the enhancement of primary production and carbon sinks has been repeatedly verified, the role of iron in upper-level production remained uninvestigated, and thus, our understanding of ecosystem responses is incomplete. In this analysis, paleorecords and modern time series are gleaned to test an extended hypothesis that tertiary-level productivity is also promoted by iron fertilization. Paleoproxies and modern records for the abundance of sockeye salmon returning to an Alaskan lake are related to climatic variables describing the flux of iron-laden Asian dust, its <em>trans</em>-Pacific transport, and its deposition into the iron-limited Gulf of Alaska sockeye salmon feeding ground. The linkage shows that for ∼2,200 years, the productivity of the salmon stock has been driven by this Asian dust supply. Data from modern observations provide more direct support for the linkage between dust-iron input, primary production, and salmon abundance. This analysis indicates that iron from Asian dust drives primary through to sockeye salmon productivity via bottom-up food-web control. This understanding of the role of iron in tertiary-level production provides a basis for the artificial enhancement of ocean living resources, but questions arise regarding the efficiency of iron fertilization in climate mitigation.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"237 ","pages":"Article 103514"},"PeriodicalIF":3.8,"publicationDate":"2025-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144270644","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":"Biogeochemical features along the northern and central Patagonian shelf during a spring cruise: implications for biological productivity","authors":"Valentina Valdés-Castro ,&nbsp;Diego A. Narváez ,&nbsp;Marcelo H. Gutiérrez ,&nbsp;Silvio Pantoja-Gutiérrez ,&nbsp;Camila Fernández","doi":"10.1016/j.pocean.2025.103511","DOIUrl":"10.1016/j.pocean.2025.103511","url":null,"abstract":"<div><div>The Patagonian fjords, channels, and glacial meltwater plays a key role in shaping the hydrography and biogeochemistry of the Southeastern Pacific Ocean, through substantial exchanges with open ocean waters. However, the continental shelf between 46°S and 48°S remains less explored, leaving critical gaps in our understanding of nutrient dynamics and productivity patterns. This study investigates latitudinal gradients in water column biogeochemistry and productivity in northern and central Chilean Patagonia during the austral spring of 2018. We identified three distinct zones: a northern area (41°S and 46°S) with higher temperature, salinity, dissolved oxygen, and chlorophyll-a concentrations; an exchange zone between Guafo entrance and Moraleda Channel, characterized by elevated inorganic nutrient concentrations; and a southern area (46°S and 48°S) with increased ammonium concentrations and the lowest silicic acid levels. Offshore stations in the northern area exhibited the highest integrated primary production rates (up to 6.3 g C m⁻² d⁻¹), primarily sustained by nitrate uptake (<em>ƒ</em> ratios up to 0.98). In contrast, the southern area showed a preference for ammonium assimilation, with lower <em>ƒ</em> ratios (0.1–0.3). These findings suggest that the northern area supports a high proportion of new primary production, which likely enhances organic matter export and the efficiency of the biological pump, whereas regenerated production in the southern area may limit carbon export potential. Our study provides the first large-scale description of the biogeochemical features of the Patagonian continental shelf, particularly around the Taitao Peninsula, offering a critical baseline for understanding biogeochemical processes in this region and its potential responses to climate change and anthropogenic pressure.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"236 ","pages":"Article 103511"},"PeriodicalIF":3.8,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144195131","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":"Census of mesoscale eddies in the Northwestern Japan Sea based on Lagrangian analysis and ship observations","authors":"A.A. Udalov,&nbsp;V.B. Lobanov,&nbsp;S.V. Prants,&nbsp;S.Y. Ladychenko,&nbsp;M.V. Budyansky,&nbsp;A.N. Salyuk","doi":"10.1016/j.pocean.2025.103513","DOIUrl":"10.1016/j.pocean.2025.103513","url":null,"abstract":"<div><div>Mesoscale eddies are intrinsic features in the Japan Sea northwest of the Subpolar Front, some of which have been sampled by the authors in different years. Using an automatic eddy-detection algorithm and altimetry-based Lagrangian maps, we have found two domains with increased occurrence frequency of anticyclones and three domains with increased occurrence frequency of cyclones, where the mesoscale eddies regularly form, circulate and decay. The census of long-lived eddies with a surface signature in 1993 – 2022 has been conducted. The distributions of these eddies over the values of nonlinearity parameter, lifetime, radius, swirl and translational velocities and the months of formation and decay have been calculated and analyzed. Using the shipboard and satellite observations and Lagrangian analysis, a few sampled anticyclones and cyclones have been studied in detail with the focus on the thermohaline properties and vertical structure, the genesis and variability. These properties differ for the eddies in the discovered formation domains. Using the Lagrangian particle-tracking method, the content of waters of subtropical and subarctic origin in the surface cores of the sampled eddies and its temporal variability have been estimated. It has been found that cyclonic eddies are associated with a dome-like lifting of isolines which can be traced down to the bottom, but they do not transport trapped water over a long distance. Anticyclonic eddies contain low-salinity water in their cores. Extremely low saline water is observed in the eddies located in the western domain, northwest of the Subpolar Front. The eddies, located at the front and to the south of it, have warm and high-salinity upper cores formed by modified subtropical water and also contain secondary cores of low-salinity water at an intermediate depth. By trapping and transporting low-salinity water, these eddies contribute to distribution of low-salinity intermediate water in the Japan Sea.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"236 ","pages":"Article 103513"},"PeriodicalIF":3.8,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144205300","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}