Progress in Oceanography最新文献

{"title":"Massive occurrence of a new soft-walled monothalamous foraminifer, Bathyallogromia brandtae n.sp., in the hadal Aleutian trench","authors":"Jan Pawlowski ,&nbsp;Andrew J. Gooday ,&nbsp;Maria Holzmann","doi":"10.1016/j.pocean.2025.103493","DOIUrl":"10.1016/j.pocean.2025.103493","url":null,"abstract":"<div><div>Large numbers of spherical, organic-walled, monothalamous foraminifera were observed and isolated from the fine-sized sediment fraction collected at hadal depths in the Aleutian trench. The foraminifer was one of the few living species found among diatom frustules that make up most of this sediment fraction. Morphologically, the species resembles the genus <em>Bathyallogromia</em> described from the Weddell Sea and subsequently found in the abyssal Arctic Ocean, and other high latitude areas but never in such massive abundance. Molecular phylogenetic analyses based on partial 18S rRNA gene sequences confirmed its generic identification as a new species within the <em>Bathyallogromia</em> clade that is described here as <em>Bathyallogromia brandtae</em> sp.nov. Our study offers new evidence that deep-sea monothalamous foraminifera can proliferate in extreme hadal settings and have biogeographic distributions that are more restricted than is commonly assumed.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"235 ","pages":"Article 103493"},"PeriodicalIF":3.8,"publicationDate":"2025-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143947165","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-wide morphology and metabarcoding-based comparison of ichthyoplankton diversity and community structure in the Gulf of Mexico","authors":"Miguel A. Martínez-Mercado ,&nbsp;Jesus C. Compaire ,&nbsp;Frank J. Hernández ,&nbsp;Glenn Zapfe ,&nbsp;Sylvia P.A. Jiménez-Rosenberg ,&nbsp;Anaid Saavedra-Flores ,&nbsp;Clara E. Galindo-Sánchez ,&nbsp;Leticia Barbero ,&nbsp;Sharon Z. Herzka","doi":"10.1016/j.pocean.2025.103482","DOIUrl":"10.1016/j.pocean.2025.103482","url":null,"abstract":"<div><div>Comprehensive surveys of marine fish egg and larval assemblages provide insight into spawning distribution, dispersal, transport processes, connectivity, and recruitment. We report on a rare basin-wide synoptic survey of fish eggs and larvae sampled throughout the Gulf of Mexico (GoM), including the Loop Current (LC) and Bahamas Channel in the Atlantic. Based on paired sample collections, we identified fish larvae through morphology-based identification at the family level and with cytochrome oxidase I metabarcoding to genera or species; eggs were identified by metabarcoding. Sampling within one-month during summer 2017 included on-shelf (&lt;200 m depth) and off-shelf stations (depths &gt;1000 m). We found general agreement between identification approaches at the family level, but the higher taxonomic resolution achieved with metabarcoding and the inclusion of ecological information such as adult habitat indicated three predominant assemblages: oceanic, shelf, and LC-associated. In larval samples, 72 and 77 families were identified based on morphology and metabarcoding, respectively and 62 families (70 %) were identified with both methods. Thirty-nine families were identified in fish egg samples, likely due to their shorter stage duration. The greater taxonomic resolution of metabarcoding yielded 265 and 75 species in larvae and egg samples, respectively. While family-level diversity indices did not differ between on and off-shelf assemblages, species-level analysis indicated significantly higher egg and larval diversity at on-shelf stations. Hence, family-level analyses may be too coarse to elucidate patterns in alpha diversity. Family-level cluster analysis indicated on– and off-shelf stations grouped separately, except for an off-shelf station off the Mississippi River that reflected local offshore transport of neritic taxa. Metabarcoding detected an additional cluster within the LC’s path of travel that included Caribbean reef taxa. All off-shelf stations included larvae of neritic families, reflecting offshore transport throughout the GoM. In contrast, only some on-shelf stations included oceanic families, indicating less prevalent oceanic-to-shelf transport. Amplicon sequence variants, roughly indicative of abundance, showed a positive association with mean water column temperature and dissolved oxygen, known to influence spawning and larval growth and development, as well as surface chlorophyll, a proxy for larval food availability. Off-shelf stations were positively correlated with indicators of water masses and mesoscale eddies. Similar results were found for the egg stage, but the correlation with chlorophyll <em>a</em> was insignificant, consistent with endogenous feeding during the embryonic stage. Our synoptic view of the GoM’s early life stages of fishes can serve as a reference for examining the impacts of climate change and other anthropogenic disturbances.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"235 ","pages":"Article 103482"},"PeriodicalIF":3.8,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143937640","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":"Variability and forcings of high turbidity events in the northern Adriatic sea from analysis of in-situ long-term data: A methodological approach","authors":"Francesco Riminucci ,&nbsp;Davide Bonaldo ,&nbsp;Lucilla Capotondi ,&nbsp;Mariangela Ravaioli ,&nbsp;Caterina Bergami","doi":"10.1016/j.pocean.2025.103483","DOIUrl":"10.1016/j.pocean.2025.103483","url":null,"abstract":"<div><div>Long-term data series (2012–2021) of physical and oceanographic parameters at the LTER-Italy research site “Delta del Po and Costa Romagnola’’, encompassing the Po river delta and the surrounding coastal areas, were analyzed to investigate the variability of surface turbidity in the North-Western Adriatic shelf. This shallow coastal environment is characterized by high river runoff, strong variability in wind regimes (direction and speed) and sea state (wave height). Both meteorological and oceanographic factors drive the local pattern of surface turbidity. This study focuses on an in-situ data analysis to recognize the main forcing responsible for high surface turbidity events (HTEs) along the coastal area. The dataset analyzed combines surface optical turbidity and salinity data, along with meteorological, hydrographic, and wave data from fixed point observing systems. While the main and most intense turbidity events (NTU &gt; 10) in the Po Delta area are primarily caused by suspended sediments from river floods and wind-driven resuspension events, the high correlation between turbidity and wave height indicates that waves are primary driving factors along the Emilia-Romagna coast southward. The results from this study provide a methodological approach based on thresholds and proxies of physical parameters for quantifying variations of HTEs and identifying their main forcing in coastal areas.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"235 ","pages":"Article 103483"},"PeriodicalIF":3.8,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143885926","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":"Connection of central South China Sea current variability with tropical Rossby waves in the western North Pacific","authors":"Mac Euan D. Malugao ,&nbsp;Sen Jan ,&nbsp;Ming-Huei Chang ,&nbsp;Tung-Yuan Ho ,&nbsp;Yiing Jang Yang","doi":"10.1016/j.pocean.2025.103481","DOIUrl":"10.1016/j.pocean.2025.103481","url":null,"abstract":"<div><div>This study investigates the connection between the current velocity variations in the central South China Sea (SCS) and westward-propagating tropical Rossby waves in the western North Pacific, using satellite altimeter observations and coastal tide-gauge data supplemented by numerical modeling. This work is focused on the dynamic link between the intraseasonal velocity oscillations observed in the central-eastern SCS in summer 2017 and the Rossby waves that impinge on the east coast of the Philippine Archipelago. Low-pass-filtered satellite sea level anomaly (SLA) data and coastal sea level records suggest that Rossby waves can propagate into the Celebes Sea and Sulu Sea, eventually reaching the central SCS. A three-dimensional, primitive equation model shows that Rossby wave-associated SLA signals transmit through the Philippine Archipelago to the central SCS via the Celebes Sea-Sibutu Passage-Sulu Sea-Mindoro Strait route, with modeled SLA propagation timings that are consistent with the observations. As the Rossby wave reaches the eastern Philippines, approximately one-third of the incident wave energy from a meridional section east of the Philippines (132°E, between 2°N and 15°N) is transmitted into the Celebes Sea and Luzon Strait, whereas approximately two-thirds of the energy is dissipated, transformed, or reflected along the Philippine coast. Approximately 15 % of the energy entering the Celebes Sea passes through the Sibutu Passage into the Sulu Sea, and ∼10 % exits the Mindoro Strait into the central SCS. These suggest that 2−5 % of the incident energy from the western North Pacific transmitted into the central SCS and influences sea level and velocity variations there.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"235 ","pages":"Article 103481"},"PeriodicalIF":3.8,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143885925","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":"Linking physical processes to biological responses: Interdisciplinary observational insights into the enhanced biological productivity of the Cape Verde Archipelago","authors":"Florian Schütte ,&nbsp;Anna Christina Hans ,&nbsp;Marco Schulz ,&nbsp;Rebecca Hummels ,&nbsp;Olivier Assokpa ,&nbsp;Peter Brandt ,&nbsp;Rainer Kiko ,&nbsp;Arne Körtzinger ,&nbsp;Björn Fiedler ,&nbsp;Tim Fischer ,&nbsp;Elizandro Rodrigues ,&nbsp;Henk-Jan Hoving ,&nbsp;Helena Hauss","doi":"10.1016/j.pocean.2025.103479","DOIUrl":"10.1016/j.pocean.2025.103479","url":null,"abstract":"<div><div>The Cape Verde Archipelago (CVA) is a hotspot of biological productivity in the oligotrophic central North Atlantic, supporting a highly diverse ecosystem. Twenty years of interdisciplinary observational data are used to investigate the primary physical processes driving this productivity and their impacts on the composition of biological life across the food web of the CVA. Three dominant physical processes are identified: <strong><em>I.</em></strong> <em>Atmospheric forced island wakes:</em> Wind interactions with the topography of Santo Antão and Fogo generate local wind shear, creating surface-intensified, productive eddy fields that extend several island diameters downstream. <strong><em>II.</em></strong> <em>Interaction of remotely generated mesoscale eddies with the CVA:</em> Nitrate-rich eddies generated off the coast of West Africa interact with the CVA by colliding with the eastern islands, or by passing near shallow bathymetry. This interaction enhances submesoscale activity, likely driven by unbalanced mesoscale flow, leading to hotspots of vertical advection and mixing. Our observations indicate, in addition, interactions between passing eddies and island-induced processes, such as an elevated internal wave field and wind curl in lee of the islands. This results in up to a tenfold increase in mixing within near-island eddies. <strong><em>III.</em></strong> <em>Interactions of tidal flows and internal waves with the CVA:</em> Internal wave breaking at specific hotspots, such as south of Santo Antão, leads to elevated vertical mixing rates, up to 1000 times higher than at reference points. The mean internal wave field in the CVA is over twice as energetic as in the open ocean, and even stronger at distinct hotspots. These three physical processes, although different in nature, all enhance upward nitrate flux, thereby promoting significantly higher chlorophyll concentrations. This, in turn, forms the foundation of the local pelagic food web, including mesozooplankton and micronekton, such as mesopelagic fishes, whose abundance increase three- to tenfold at these local hotspots. The composition of the biological communities is highly diverse and varies across different regions and physical processes. Annual landings of mackerel and tuna on the CVA, as well as the abundance of humpback whales, are positively correlated with annual mean chlorophyll concentrations. Overall, our study reveals a strong correlation between nitrate supply to the euphotic zone, driven by various physical processes, and species abundance throughout the food web, extending to large predators. These findings underscore the crucial role of local physical processes in shaping the structure of marine communities from lower to higher trophic levels, explaining biological diversity in the marine environment of the CVA and beyond.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"235 ","pages":"Article 103479"},"PeriodicalIF":3.8,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143947166","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":"Mapping internal lee wave generation and dissipation in the deep South China sea","authors":"Zhenhua Xu ,&nbsp;Ji Li ,&nbsp;Peiwen Zhang ,&nbsp;Jia You ,&nbsp;Jianping Gan","doi":"10.1016/j.pocean.2025.103474","DOIUrl":"10.1016/j.pocean.2025.103474","url":null,"abstract":"<div><div>Abyssal mixing induced by internal wave breaking has been proposed as an essential process that maintains and modulates the deep cyclonic circulation and meridional overturning circulation in the South China Sea (SCS). Previous studies have primarily focused on internal tides, leaving limited exploration on internal lee waves and their roles in mixing the SCS. This study represents the first basin-scale estimation of the lee-wave energy flux from the geostrophic flow and exploration of lee-wave-induced mixing in the SCS. Utilizing an improved spectra method with the synthetic full-scaled bathymetry, lee wave generation is estimated employing Bell theory with the outputs from the China Sea Multi-Scale Ocean Modeling System. The Luzon Strait (LS) features the strongest lee wave generation, reaching up to 19.7 GW. In the SCS interior, the total energy flux is estimated at 1.3 GW, with 70% occurring in the deep basin. In the basin area, energy flux from the mean flow surpasses that from eddy flow, whereas in the marginal area, the dominant energy flux is from eddy flow. This study reveals seasonal variation in lee wave generation, closely related to the seasonality of the deep-water overflow from the LS. The mixing driven by lee waves is found comparable with that driven by internal tides in the deep SCS basin. This study emphasizes the potentially significant lee wave energy and induced mixing in the deep SCS basin, which should be well-mapped and parameterized in ocean models for a better characterization of multiscale dynamics and energetics in the SCS.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"235 ","pages":"Article 103474"},"PeriodicalIF":3.8,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143879489","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":"Kinorhyncha community in the Aleutian Trench (North Pacific Ocean) with the description of a new Cristaphyes species (Allomalorhagida, Pycnophyidae)","authors":"Nuria Sánchez ,&nbsp;Frederic Bonk ,&nbsp;Alberto González-Casarrubios","doi":"10.1016/j.pocean.2025.103475","DOIUrl":"10.1016/j.pocean.2025.103475","url":null,"abstract":"<div><div>Several species of trench-dwelling meiofaunal animals, including Kinorhyncha, have been described in recent years; however, our knowledge on kinorhynchs inhabiting abyssal and even hadal depths is still extremely scarce. In the present study, we explore the Kinorhyncha community of the Aleutian Trench, North Pacific Ocean, an under-sampled region in terms of meiofauna. As a result, a new species of <em>Cristaphyes</em> inhabiting abyssal and hadal depths of the trench is described. <em>Cristaphyes unangax</em> sp. nov. is characterized by the presence of middorsal processes on segments 1 – 10, with the last one extending well-beyond the posterior margin of the trunk. <em>Cristaphyes unangax</em> sp. nov. thus becomes the fourth hadal species described within the phylum Kinorhyncha. In terms of biodiversity, abundance of adult kinorhynchs remains relatively low along the trench’s depth gradient (c.a. 3.500 – 7.200 m), except at two sites: one at the axis and another at the slope. The higher abundance at the axis aligns with patterns in other trenches, where organic matter accumulation enhances microbial activity, supporting meiofaunal communities. The elevated specimens at the slope station, located at abyssal depth, may result from Aleutian upwelling currents or trench terraces that facilitate food deposition. The Kinorhyncha community in the Aleutian Trench is dominated by <em>Echinoderes ultraabyssalis</em> and includes another nine species, many shared with the North Pacific and Arctic. These findings suggest that meiofauna in the North Pacific can disperse across bathymetric barriers, potentially linking the Aleutian and Kuril-Kamchatka trenches. Additionally, the Aleutian Trench may serve as a migration corridor for meiofauna between the North Pacific and Arctic, aided by strong bottom currents.</div><div><strong>Zoobank</strong>: urn:lsid:zoobank.org:pub:56D1BA0B-3D9F-4547-84BC-C9BAFCA1D220</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"236 ","pages":"Article 103475"},"PeriodicalIF":3.8,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144084481","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":"Presence of two eddies in close proximity drives large spatial and temporal heterogeneity in the euphotic zone","authors":"Simon Ramondenc ,&nbsp;Richard S. Lampitt ,&nbsp;Maria Fredrika Norrbin ,&nbsp;Anna Belcher ,&nbsp;Wilken-Jon von Appen ,&nbsp;Morten H. Iversen","doi":"10.1016/j.pocean.2025.103476","DOIUrl":"10.1016/j.pocean.2025.103476","url":null,"abstract":"<div><div>Oceanic mesoscale structures, such as eddies, play a fundamental role in ocean circulation, ocean biogeochemical cycles and plankton ecology. They cause lateral and vertical advection, as well as interact with vertical mixing, which is predicted to promote episodic fluxes of macronutrients to the surface ocean. However, the interactions between mesoscale eddies can generate submesoscale fronts and filaments occurring over short temporal and spatial scales and thus their impact on ocean biogeochemistry has been difficult to characterize. During an expedition to the Porcupine Abyssal Plain (PAP) site in the Northeast Atlantic in June 2013, we studied the interface between a cyclonic and an anticyclonic eddy, measuring nutrient and chlorophyll-a concentrations, zooplankton abundance and community structure, and marine snow aggregate abundance and sinking velocities. We observed that eddy rotation and a storm event induced, respectively, lateral stirring and vertical mixing of the two distinct water masses, driving spatial and temporal biogeochemical heterogeneity at the PAP site. Furthermore, we observe that diel and vertical variations in aggregate type and abundance were closely linked to the vertical distribution and abundance of zooplankton, suggesting that zooplankton were the main gatekeepers of carbon flux. Our findings suggest that the interactions between mesoscale structures could significantly modify organic carbon export, as well as provide sustenance for higher trophic levels, processes that have implications for fisheries and global climate.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"235 ","pages":"Article 103476"},"PeriodicalIF":3.8,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143868956","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":"Significance of temperature and salinity in the dynamics of diatoms and dinoflagellates along the coastal Yellow Sea","authors":"Chenshi Weng ,&nbsp;Dongsheng Ding ,&nbsp;Qian Yang ,&nbsp;Lin Zhu ,&nbsp;Jun Sun ,&nbsp;Keming Qu ,&nbsp;Zhengguo Cui ,&nbsp;Yuqiu Wei","doi":"10.1016/j.pocean.2025.103478","DOIUrl":"10.1016/j.pocean.2025.103478","url":null,"abstract":"<div><div>Diatoms and dinoflagellates are two typical functional groups of phytoplankton, which account for a major part of global primary production and play an important role in ecosystem processes and biogeochemical cycles. It is well known that the dynamics of diatoms and dinoflagellates in the ocean are mainly driven by changes in hydrological conditions related to climate change and human activities. However, little is known about their ability to adapt to changing ocean environments, making it difficult to predict whether and how they will adapt. Analysis of field data from the coastal Yellow Sea (2021–2023) showed that temperature and salinity changes, driven by seasonal variations, notably affected the dynamics of diatoms and dinoflagellates. Moreover, the seasonal dynamics of these two groups exhibited distinct responses to temperature, salinity, and their interactions. Specifically, diatoms exhibited greater heat resistance than dinoflagellates, but were more sensitive to salinity changes, often dominating during the warmer, less saline summer and autumn seasons. In contrast, dinoflagellates, due to their nutritional strategies, showed greater tolerance to salinity changes and often co-dominated with diatoms under high salinity conditions. Overall, changes in temperature and salinity had a large impact on diatoms and dinoflagellates in coastal Yellow Sea, albeit with different relationships. Therefore, future research should focus on the long-term effects of combined temperature and salinity changes, as well as the potential influence of other environmental variables such as nutrient availability.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"234 ","pages":"Article 103478"},"PeriodicalIF":3.8,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143854840","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 stable-carbon-isotope-based constraint of bulk particulate organic carbon dynamics and budgets in the Yellow Sea: Combining field surveys and isotope fractionation modeling","authors":"Cong-cong Guo ,&nbsp;Shu Yang ,&nbsp;Qing-shan Luan ,&nbsp;Qian-qian Liu ,&nbsp;Zi-chen Liu ,&nbsp;Wei-dong Zhai","doi":"10.1016/j.pocean.2025.103477","DOIUrl":"10.1016/j.pocean.2025.103477","url":null,"abstract":"<div><div>The isotopic composition of POC (δ¹³C_POC) serves as a critical tracer for marine carbon dynamics. Its traditional applications usually assume a fixed δ¹³C value for marine phytoplankton (δ¹³C_phyto) of − 20 ± 1 ‰, overlooking spatiotemporal variabilities in phytoplankton carbon isotope fractionation (<em>ε</em>_P). This study quantifies <em>ε</em>_P-mediated δ¹³C_POC variations in the Yellow Sea – a temperate shelf sea characterized by seasonal stratification, intense diatom blooms, and terrestrial inputs – by coupling isotope fractionation models (passive CO₂aq diffusion vs. active HCO₃^– transport) with multi-season δ¹³C measurements of Dissolved Inorganic Carbon (DIC) and δ¹³C_POC. During algal bloom periods, δ¹³C_POC values were relatively heavier (−20 ± 1 ‰), driven by active HCO₃^– uptake under low CO₂aq concentrations ([CO₂aq]). Strong agreement between δ¹³C_POC and modeled δ¹³C_phyto values confirmed compositional similarity between POC and algal biomass, with <span><math><mrow><msub><mrow><mi>ε</mi></mrow><mrow><mi>P</mi></mrow></msub></mrow></math></span> exhibiting significant covariation with [CO₂aq]. In non-bloom periods, lighter δ¹³C_POC values (from − 26 to − 24 ‰) dominated surface layers, with even more depleted signatures (&lt;−26 ‰) occurred in the Deep Chlorophyll Maximum (DCM) and middle layers. Although detritus inputs caused deviations of δ¹³C_POC from modeled δ¹³C_phyto values, temperature-dependent correlations still revealed <span><math><mrow><msub><mrow><mi>ε</mi></mrow><mrow><mi>P</mi></mrow></msub></mrow></math></span>-related isotopic dynamics in POC. This research underscores the necessity of using environment-specific δ¹³C_phyto values to refine POC budget estimates, reducing flux uncertainties by 20–30 % and minimizing isotopic errors to &lt; 1 ‰ across different timescales. This work establishes a framework for incorporating δ¹³C_phyto plasticity into coastal carbon models, resolving long-standing paradoxes of isotopically light POC (&lt;−26 ‰) in marine-dominated systems and advancing high-resolution carbon flux estimates in marginal seas.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"236 ","pages":"Article 103477"},"PeriodicalIF":3.8,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144071858","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}