Progress in Oceanography最新文献

{"title":"Variability of near-inertial internal wave energy in the Kuroshio extension from CPIES array observations","authors":"Y.R. Mu ,&nbsp;Y.S. Xu ,&nbsp;J.H. Park","doi":"10.1016/j.pocean.2025.103650","DOIUrl":"10.1016/j.pocean.2025.103650","url":null,"abstract":"<div><div>Near-inertial internal waves (NIIWs) play a central role in ocean mixing and energy transfer, and understanding their local variability is essential for quantifying ocean energetics. This study investigates the local drivers of NIIW variability in the Kuroshio Extension System Study (KESS) region using observations from a Current-and Pressure-sensor-equipped Inverted Echo Sounder (CPIES) array deployed over a 600 km by 600 km area, assuming negligible net NIIW flux. We developed an empirical model to quantify the contributions of wind-induced near-inertial energy flux (WNEF), mixed layer depth (MLD), and relative vorticity (<span><math><mrow><mi>ζ</mi></mrow></math></span>), which have dominant influences on NIIW variability, accounting for 39 %, 41 %, and 20 % of the variability, respectively. WNEF and MLD positively correlate with NIIW energy, while <span><math><mrow><mi>ζ</mi></mrow></math></span> shows a negative correlation. These findings highlight the significance of local processes in modulating NIIW energy and improving our understanding of ocean mixing dynamics by transitioning from qualitative to quantitative analysis.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"241 ","pages":"Article 103650"},"PeriodicalIF":3.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145731518","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":"Ecological and spatial factors shaping abyssal and hadal peracarid crustacean communities in the eastern Aleutian Trench (NE Pacific)","authors":"Davide Di Franco ,&nbsp;Stefanie Kaiser ,&nbsp;Andreas Kelch ,&nbsp;Mathis Preikschardt ,&nbsp;Magdalena Błażewicz ,&nbsp;Nils Brenke ,&nbsp;Sarah Gerken ,&nbsp;Kamila Głuchowska ,&nbsp;Karen Jeskulke ,&nbsp;Henry Knauber ,&nbsp;Katharina Kohlenbach ,&nbsp;Anne Helene S. Tandberg ,&nbsp;Anna Jażdżewska ,&nbsp;Angelika Brandt","doi":"10.1016/j.pocean.2025.103651","DOIUrl":"10.1016/j.pocean.2025.103651","url":null,"abstract":"<div><div>The abyssal and hadal deep sea, characterised by high pressures, low temperatures, and limited light availability, hosts a remarkable diversity of organisms that have adapted to these harsh conditions. Despite its vastness, the deep sea remains relatively unexplored, and our understanding of the factors governing its community composition, diversity, and abundance is still limited. In this study, we aim to elucidate the various factors that contribute to shaping deep-sea peracarid communities and provide insights into their ecological dynamics. Benthic material was collected during the AleutBio (SO293) expedition aboard the RV <em>Sonne</em> from July 24th to September 6th, 2022 in the Northeast Pacific Ocean. A total of 19 samples were collected with an epibenthic sledge at depths ranging from 3,517 to 7,254 m. In total, 5,400 peracarid specimens were collected, with amphipods and isopods being the most dominant groups, accounting for 35 % and 36 % (1,546 and 1,591 ind./1,000 m haul) respectively, followed by cumaceans and tanaidaceans, which each contributed 13 % of the total peracarid composition (584 and 556 ind./1,000 m). Hierarchical cluster analysis and non-metric multidimensional scaling (nMDS) revealed dissimilarity in the abundance patterns between hadal and abyssal stations, highlighting significant variation in assemblage structure. Further Redundancy Analysis (RDA), showed that depth was the primary environmental factor driving peracarid abundance across the stations. The results contribute valuable insights into the distribution patterns of peracarids in the Aleutian Trench region and underscores the need for further investigations into the role of environmental variables in structuring deep-sea communities.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"241 ","pages":"Article 103651"},"PeriodicalIF":3.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786139","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":"Controls of sea–air O2 and CO2 exchanges along the Patagonian shelf-break: the role of temperature and phytoplankton communities","authors":"Luísa M. Garcia ,&nbsp;Iole Beatriz M. Orselli ,&nbsp;Virginia Maria Tavano ,&nbsp;Carlos Rafael B. Mendes ,&nbsp;Carlos Alberto E. Garcia ,&nbsp;Rosane G. Ito ,&nbsp;Catherine Goyet ,&nbsp;Rodrigo Kerr","doi":"10.1016/j.pocean.2025.103629","DOIUrl":"10.1016/j.pocean.2025.103629","url":null,"abstract":"<div><div>Considering that oxygen (O₂) and carbon dioxide (CO₂) are subject to many of the same biological and physical drivers, a combined investigation of these gases provides a comprehensive framework to elucidate the mechanisms that govern their sea-air exchanges. To investigate these controls on the Patagonian shelf, we analysed temperature, salinity, dissolved O₂, and continuous CO₂ measurements from springs of 2004, and 2006–2008, and summers of 2007, 2008 and 2009. Phytoplankton biomass was classified by pigment composition via high-performance liquid chromatography and microscopic counts. The findings suggest that in the northern shelf (36°–40°S), despite low phytoplankton biomass (mainly haptophytes, 45 %), photosynthesis modulated fluxes, leading to O₂ outgassing (14 ± 9 mmol m⁻² d⁻¹) and CO₂ uptake (–4 ± 3 mmol m⁻² d⁻¹). Between 40°–51°S, spring diatom blooms (82 % diatom and up to 22.5 mg m^-3 Chl–<em>a</em>) were correlated with the highest O₂ outgassing (91 mmol m⁻² d⁻¹) and CO₂ uptake (–40 mmol m⁻² d⁻¹), driven by the photosynthesis. In contrast, around 50°S, summer fluxes were associated with a predominance of net respiration, thermal processes, and the advection of O₂-undersaturated waters, resulting in an O₂and CO₂ uptake (–41 ± 7 mmol m⁻² d⁻¹ and –9 ± 4 mmol m⁻² d⁻¹, respectively). South of 52°S, summer conditions shifted the region from a CO₂ sink to a source due to warming and lower phytoplankton biomass (0.6 ± 0.5 mg m⁻³).</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"241 ","pages":"Article 103629"},"PeriodicalIF":3.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145583774","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":"Nitrogenous sources for summertime phytoplankton at two contrasting stations in the subarctic and subtropical western North Pacific","authors":"C. Yoshikawa ,&nbsp;H. Yamaguchi ,&nbsp;N.O. Ogawa ,&nbsp;A. Makabe ,&nbsp;M. Sato ,&nbsp;Y. Mino ,&nbsp;K. Matsumoto ,&nbsp;Y. Nakano ,&nbsp;S. Kawagucci ,&nbsp;T. Fujiki ,&nbsp;N. Harada ,&nbsp;M. Kawachi ,&nbsp;N. Ohkouchi","doi":"10.1016/j.pocean.2025.103614","DOIUrl":"10.1016/j.pocean.2025.103614","url":null,"abstract":"<div><div>Nitrogen isotope compositions (<em>δ</em>¹⁵N) of phytoplankton, nitrate, and ammonium can reveal the fraction of nitrate versus ammonium utilization by phytoplankton. The <em>δ</em>¹⁵N values of ammonium in the open ocean has been rarely determined because of its low concentration. However, interpretations of phytoplankton nitrogen sources using <em>δ</em>¹⁵N values has required the ammonium <em>δ</em>¹⁵N values. Here, we determined the <em>δ</em>¹⁵N values of phytoplankton, nitrate, and ammonium in the summertime of 2012–2016 at contrasting stations in the subarctic and subtropical western North Pacific. We also developed a nitrogen isotope model to constrain the nitrogenous sources of the phytoplankton and compensate for the lack of observations. At the subarctic station, the <em>δ</em>¹⁵N values of nitrate and phytoplankton in the surface waters were 8.5 ‰ and − 5.9 ± 0.5 ‰ to − 3.3 ± 0.5 ‰, respectively. At the subtropical station, the <em>δ</em>¹⁵N values of nitrate and phytoplankton were 6.8 ‰ and1.0 ± 0.7 ‰, respectively. The differences in <em>δ</em>¹⁵N values between phytoplankton and nitrate were as large as 11.8 ‰ to 14.4 ‰ at the subarctic station and as small as 5.8 ‰ at the subtropical station. Although the ammonium concentration was below the detection limit at the subtropical station, it was 0.4 μM at the subarctic station and the <em>δ</em>¹⁵N value was 4.5 ± 1.9 ‰, much lower than that of nitrate. A model constrained by the nitrogen isotope measurements revealed that, during summer, the phytoplankton at the subarctic station assimilated more than half of their nitrogen from ammonium. At the subtropical station, ammonium assimilation was dominant.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"240 ","pages":"Article 103614"},"PeriodicalIF":3.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145404690","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":"Population structure study across the North Pacific for representatives of the deep-sea family Neotanaidae (Crustacea: Peracarida) reveals cryptic species separated by depth and geographical distance","authors":"Emma Palacios Theil,&nbsp;Andrea Desiderato,&nbsp;Serena Mucciolo,&nbsp;Magdalena Błażewicz","doi":"10.1016/j.pocean.2025.103595","DOIUrl":"10.1016/j.pocean.2025.103595","url":null,"abstract":"<div><div>Neotanaids are deep-sea benthic peracarids. As such, they lack a planktonic larval stage, what, together with their relatively small sizes and lack of swimming adaptations, confers them a priori low dispersal abilities. Other peracarids with low swimming abilities, for example isopods of the families Nannoniscidae and Desmosomatidae, show generally distribution ranges of about 500 km. Nevertheless, recent population structure analyses based on molecular markers (COI and 16S) have revealed a neotanaid North Pacific species with a distribution range of more than 2500 km. The species was collected in the western North Pacific, in the Sea of Okhotsk in 2015 during the SokhoBio campaign, and in 2022 in the eastern North Pacific, in the Aleutian Basin, during the AleutBio scientific cruise. During this latter campaign, additional neotanaids were recorded from deeper waters south of the Aleutian Islands, specifically at three stations at the northern slope of the Aleutian Trench (4215–4501 m depth), as well as at seven stations in the trench itself and at the southern slope (5100–6954 m depth). Species delimitation analyses have shown that these neotanaids belong to different taxonomic units, sorted not only by geographical location, but also by their depths. Two groups of neotanaids sampled only 50 km apart belong to different species, separated by depth. These findings indicate that previous assumptions about neotanaids having low dispersal abilities might need to be re-evaluated. In addition, further analyses of other neotanaid species with unusually large depth ranges, especially those clearly surpassing the turnover point for depth zonation in marine ecosystems (at a depth of about 4000 m), such as <em>Neotanais affinis</em>, <em>N. hadalis</em>, or <em>N. armiger</em>, will most likely reveal additional cryptic species in the future.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"240 ","pages":"Article 103595"},"PeriodicalIF":3.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145425673","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":"Monthly and seasonal variations in ocean near-surface gradients around Santo Antão Island: A 20-year MODIS-aqua study","authors":"Cassandra Santos-Pacheco ,&nbsp;Issah N. Suleiman ,&nbsp;Tiago Da Rosa Serpa ,&nbsp;Miguel Figueiredo ,&nbsp;Ana Martins","doi":"10.1016/j.pocean.2025.103654","DOIUrl":"10.1016/j.pocean.2025.103654","url":null,"abstract":"<div><div>Understanding the baseline environmental conditions of the Santo Antão marine ecosystems is essential for effective conservation. This study characterised the long-term spatial variability of near-surface biophysical properties of the waters surrounding Santo Antão by utilizing 20 years of MODIS-Aqua Level-2 imagery with 1 km spatial resolution for Ocean Colour and Thermal Infrared parameters, supplemented by altimetry data. Sea Surface Temperature (SST) results revealed a persistent thermal gradient, with warmer waters in the NW-W-SW quadrant and cooler waters in the NE-E-SE quadrant, indicating the influence of regional oceanic currents and interactions between subtropical and tropical gyres. Chlorophyll <em>a</em> (Chl <em>a</em>), Diffuse Attenuation Coefficient (Kd₄₉₀), and Particulate Organic Carbon (POC) exhibited similar spatial gradients and were highly correlated, reflecting the oligotrophic nature of Case-1 waters. Notably, the correlation between Kd₄₉₀ and Chl a was strong (r ≈ 0.92), while POC showed an even higher correlation (r ≈ 0.95), reinforcing their roles as significant indicators of phytoplankton biomass. In contrast, Particulate Inorganic Carbon (PIC) concentrations displayed distinct spatial patterns and demonstrated a weak negative correlation with Chl <em>a</em> (r ≈ -0.27), indicating that PIC operates independently of the bulk phytoplankton community represented by Chl <em>a</em>. This independence emphasises the need to interpret PIC values with caution, as they may not accurately reflect biological productivity in these waters. Photosynthetically Available Radiation (PAR) displayed limited seasonal variation and a weak negative correlation with Chl <em>a</em>, suggesting that light availability is not a primary limiting factor for phytoplankton productivity in the region. The observed spatial patterns and gradients in biophysical parameters are interpreted in the context of various ocean–atmosphere interactions, including the prevailing northeast trade winds, Sea Surface Height (SSH), and surface currents, which are modulated by larger-scale circulation patterns. These mechanisms should influence nutrient availability and ultimately affect productivity distribution around the island. Overall, this study highlights the complex interplay of monthly and seasonal ocean–atmosphere spatial dynamics, along with regional and large-scale oceanographic conditions, in shaping the near-surface gradients around Santo Antão. By integrating these diverse datasets, this study provides new insights into the region’s ocean dynamics, emphasising its significance for conservation efforts in this area.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"241 ","pages":"Article 103654"},"PeriodicalIF":3.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145785688","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":"Ice melt season in the Kara Sea: Size-fractionated primary production and chlorophyll-a, evolution of the subsurface chlorophyll maximum layer and its contribution to total water column values","authors":"Andrey B. Demidov ,&nbsp;Tatiana A. Belevich ,&nbsp;Anna V. Kostyleva ,&nbsp;Valentina M. Sergeeva ,&nbsp;Alexander A. Polukhin ,&nbsp;Vladimir A. Artemiev ,&nbsp;Andrey A. Nedospasov ,&nbsp;Dragosh I. Migali ,&nbsp;Mikhail V. Flint","doi":"10.1016/j.pocean.2025.103652","DOIUrl":"10.1016/j.pocean.2025.103652","url":null,"abstract":"<div><div>The characteristics of phytoplankton variability during spring sea ice retreat are poorly understood at the regional scale. To address this gap, three cruises were conducted in the Kara Sea from late June to early August during sea ice retreat. The present study focused on the variability of primary production (PP), chlorophyll-<em>a</em> (Chl-<em>a</em>) concentration of total and size-fractionated phytoplankton, the evolution of the subsurface Chl-<em>a</em> maximum layer (SCML), and its contribution to the total water column PP (IPP_tot) and integrated photosynthetic layer Chl-<em>a</em> (Chl_ph). During the study period, the ice-edge phytoplankton bloom was characterised by high values of IPP_tot and Chl_ph (up to 1352 mgC m⁻² d^–1 and 151.53 mg m⁻², respectively) and a dominance of microphytoplankton (&gt;20 µm) in the water column (88 % of IPP_tot and 77 % of Chl_ph on average) and in the SCML (52 % of PP and 64 % of Chl-<em>a</em> on average). The role of nano- (3 – 20 µm) and picophytoplankton (&lt;3 µm) increased with sea ice retreat. During the melt season, micro-, nano- and picophytoplankton contributed on average 50, 14 and 36 % to IPP_tot and 60, 15 and 25 % to Chl_ph, respectively. PP and Chl-<em>a</em> associated with the SCML contributed 32 % to IPP_tot and 76 % to Chl_ph. The rapid decline in IPP_tot during sea ice retreat suggests that Arctic warming, sea ice loss, and the significant increase in total PP due to newly exposed open water areas may not be accompanied by an increase in photosynthetic activity in the Arctic Ocean. During the ice melt season in the Kara Sea ∼1/3 of IPP_tot and 3/4 of Chl_ph are concentrated in the SCML, emphasizing its importance in the seasonal trophic balance and in the development of PP algorithms.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"241 ","pages":"Article 103652"},"PeriodicalIF":3.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145785777","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":"Global classification of wave height, period, and direction multivariate distributions using principal component analysis","authors":"Ophélie Choupin ,&nbsp;Joseph Harari ,&nbsp;László Könözsy","doi":"10.1016/j.pocean.2025.103660","DOIUrl":"10.1016/j.pocean.2025.103660","url":null,"abstract":"<div><div>Research on the classification of ocean surface wave patterns uses coarse spatial resolutions and approaches that are less usable for applications such as annual energy estimates for wave energy converters. Consequently, this study investigates the classification of 1–3-dimensional histograms of wave height, period, and direction at a 0.4° spatial resolution. Histograms of global grid-points have been decomposed into their main modes using principal component analysis. Each mode consists of a histogram and a map quantifying its contribution to each local wave pattern. The first mode displayed a meridional gradient of the wave height, a northeast-to-southeast gradient of the wave period, and a mix of both for the wave direction. Dominating wave systems consist of a) 1.9 m, b) 14.5 s in the basins’ southeast, c) 12.5 s north and south, and d) 9.5 s north-west. Generated remotely, c) travel and evolve over long distances to reach coasts, as b) pools, while d) is mainly generated locally or northwards. K-means was used to cluster wave patterns into 15 classes using the 10 dominant modes. Some clusters characterise regions in different basins. 1-parameter-based clusters provide more regions and alternations of clusters nearshore, while clustering the parameters together provides larger regions and less nearshore noise. The wave height and period combined classification showed good correlation and difference between the cluster’s average histogram and those of the grid-points in that cluster, while the direction was lower in regions affected by strong currents or topographic obstacles. Consequently, combining all parameters greatly decreases these two metrics.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"241 ","pages":"Article 103660"},"PeriodicalIF":3.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145844679","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":"Internal tides in the Mediterranean Sea","authors":"Bethany McDonagh ,&nbsp;Jin-Song von Storch ,&nbsp;Emanuela Clementi ,&nbsp;Nadia Pinardi","doi":"10.1016/j.pocean.2025.103647","DOIUrl":"10.1016/j.pocean.2025.103647","url":null,"abstract":"<div><div>The generation and propagation sites of internal tides in the Mediterranean Sea are mapped through a comprehensive high-resolution numerical study. Two ocean general circulation models are used for this: NEMO v3.6, and ICON-O, both hydrostatic ocean models based on primitive equations with Boussinesq approximation, where NEMO is a regional Mediterranean Sea model with an Atlantic box, and ICON a global model. Internal tides are widespread in the Mediterranean Sea. The primary generation sites: the Gibraltar Strait, Sicily Strait/Malta Bank, and Hellenic Arc, are mapped through analysis of the tidal barotropic to baroclinic energy conversion. Semidiurnal internal tides can propagate for hundreds of kilometres from these generation sites into the Algerian Sea, Tyrrhenian Sea, and Ionian Sea respectively. Diurnal internal tides remain trapped along the bathymetry, and are generated in the central Mediterranean Sea and southeastern coasts of the basin. The total energy used for internal tide generation in the Mediterranean Sea is 3.31 GW in NEMO and 1.52 GW in ICON. Wavelengths of the first baroclinic modes of the M2 tide are calculated in various regions of the Mediterranean Sea where internal tides propagate, comparing model outputs to a theory-based calculation. The models are also validated and intercompared to investigate the differences between them in their representation of internal tides.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"241 ","pages":"Article 103647"},"PeriodicalIF":3.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145839870","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":"Environmental DNA of small pelagic fish in the deep ocean","authors":"Zeshu Yu ,&nbsp;Marty Kwok-Shing Wong ,&nbsp;Jun Inoue ,&nbsp;Yuan Lin ,&nbsp;Itsuka Yabe ,&nbsp;Tomihiko Higuchi ,&nbsp;Susumu Hyodo ,&nbsp;Sachihiko Itoh ,&nbsp;Yuichiro Nishibe ,&nbsp;Hajime Obata ,&nbsp;Shin-ichi Ito","doi":"10.1016/j.pocean.2025.103625","DOIUrl":"10.1016/j.pocean.2025.103625","url":null,"abstract":"<div><div>Environmental DNA (eDNA) method has been widely used worldwide for ecological surveys of fish. However, the accuracy of eDNA in deducing fish distribution, especially vertical distribution in the open ocean, is uncertain due to insufficient observation. This paper observed and studied the eDNA vertical distribution in the open ocean, focusing on two economically important small pelagic fishes, <em>Sardinops melanostictus</em> and <em>Engraulis japonicus</em> (here after sardine and anchovy respectively) in the Northwest Pacific. From the uninhabitable deep ocean layers, their eDNA was detected and we referred them as “DP-eDNA”, which suggests eDNA from pelagic fish may exist far below where they live. Higher DP-eDNA ratios were observed for sardine and anchovy when seawater temperature was lower, likely due to slower degradation. The sardine DP-eDNA ratio was higher when chlorophyll-a concentration (and turbidity) was higher, which may suggest that the fish eDNA could be attached to phytoplankton-produced particles that enhanced the eDNA sinking. Meanwhile, for anchovy, the DP-eDNA ratio was lower when dissolved oxygen concentrations were higher, which may be caused by a faster microbial-related degradation. The eDNA sinking velocity was estimated to be 39 − 255 m day⁻¹ (sardine) and 36 − 241 m day⁻¹ (anchovy), values comparable to the observation data in particulate organic matter (POM), although the DP-eDNA formation mechanism could be more complex than simple sinking. This study recorded the downward vertical movement of DNA in open ocean and its environmental-dependent characteristics, and our results deepen the considerations that should be taken when eDNA is used to deduce the vertical distribution of fish in the open ocean.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"241 ","pages":"Article 103625"},"PeriodicalIF":3.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145559765","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}