Progress in Oceanography最新文献

{"title":"Northward intermittent pulses of Antarctic Intermediate Water beyond the Brazil/Malvinas Confluence","authors":"Michèle Baqués ,&nbsp;Giuliana Berden ,&nbsp;Marcela Charo ,&nbsp;Paola M. Dávila ,&nbsp;Alberto R. Piola","doi":"10.1016/j.pocean.2026.103726","DOIUrl":"10.1016/j.pocean.2026.103726","url":null,"abstract":"<div><div>Antarctic Intermediate Water (AAIW) contributes to the northward flow required to compensate the export of North Atlantic Deep Water from the North Atlantic Ocean to other basins and therefore plays a crucial role in the Atlantic Meridional Overturning Circulation. Based on observations and outputs from an ocean reanalysis we present evidence of a narrow band of relatively fresh (≤34.20) and oxygen rich (&gt;260 μmol.kg⁻¹) newly formed AAIW which extends northwards, past the Brazil-Malvinas Confluence (BMC) up to 34.5°S. We investigated the probability of occurrence of this phenomenon, the possible driving mechanisms, and its seasonal and inter-annual variability. Our results indicate that this flow is weak and intermittent, confined to the upper continental slope near the 1000 m isobath. The mean travel time between 38 and 39°S, south of the BMC, and 34.5°S is 205–217 days; occasionally, during the development of intense pulses, the travel time reduces to less than 60 days. The mean particle velocity during pulses is 12.60 cm.s⁻¹. A weakening or reversal of the southward flowing Brazil Current (BC) is observed prior to strong pulses; this circulation pattern could facilitate the northward pathway of relatively fresh AAIW. The BC intensifies during February-March and weakens during August-September; thus, the northward AAIW pulses are also observed more frequently in September. The northward extension of the relatively fresh variety of AAIW is also favoured by cyclonic circulations trapped against the slope onshore from the core of the BC.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"244 ","pages":"Article 103726"},"PeriodicalIF":3.6,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147602083","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":"State of deep-sea science and conservation in the Northeast Pacific: implications for policy and management","authors":"Fanny Girard ,&nbsp;Joan M. Alfaro-Lucas ,&nbsp;Amy R. Baco ,&nbsp;James P. Barry ,&nbsp;Katharine T. Bigham ,&nbsp;Lara M. Beckmann ,&nbsp;Angelika Brandt ,&nbsp;Lindsay Clark ,&nbsp;Megan A. Davies ,&nbsp;Jeffrey C. Drazen ,&nbsp;Anya Dunham ,&nbsp;Cherisse Du Preez ,&nbsp;Elva Escobar Briones ,&nbsp;Heidi Gartner ,&nbsp;Moronke K. Harris ,&nbsp;Kristen N. Johannes ,&nbsp;Amanda Kahn ,&nbsp;Stefanie Kaiser ,&nbsp;Brian R.C. Kennedy ,&nbsp;Lisa A. Levin ,&nbsp;Jesse M.A. van der Grient","doi":"10.1016/j.pocean.2026.103718","DOIUrl":"10.1016/j.pocean.2026.103718","url":null,"abstract":"<div><div>Spanning from the North American continent to the Hawaiian Ridge and from the Aleutian Ridge to the tip of the Baja California Peninsula, the deep Northeast Pacific (&gt;200 m depth) hosts a high diversity of species and habitats. While relatively well studied in comparison to other regions, deep-sea ecosystems of the Northeast Pacific still hold many unknowns. This review provides an overview of the current state of knowledge of deep pelagic and benthic ecosystems in the Northeast Pacific in the context of climate change and increasing anthropogenic pressures. Regional trends in biodiversity, area-based management measures and research effort are synthesized to identify gaps in scientific knowledge, management and conservation. Based on the compilation of available literature and data extracted from open access databases, we found that scientific knowledge and research effort were unevenly distributed among habitats, with the most widespread habitats (e.g., abyssopelagic and abyssal plains, areas beyond national jurisdiction – ABNJ) being the most undersampled. Similarly, the distribution and level of protection of marine protected areas varied between countries and deep-sea habitat types, with virtually no protection in ABNJ. This review provides a comprehensive summary for scientists and managers, including recommendations on how to fill remaining scientific knowledge gaps, expand deep-sea observations to ABNJ and poorly known habitats, increase capacity for deep-sea research, improve data sharing and better support conservation and management. These recommendations aim to prioritize future research and improve sustainable management in alignment with the goals of the United Nations Decade of Ocean Science for Sustainable Development.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"244 ","pages":"Article 103718"},"PeriodicalIF":3.6,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147501778","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":"Characterising submesoscale processes, uplift and subduction across diverse fronts in the East Australian Current System","authors":"Marina V.C. Azaneu ,&nbsp;Moninya Roughan ,&nbsp;Shane R. Keating ,&nbsp;Amandine Schaeffer ,&nbsp;Christina Schallenberg","doi":"10.1016/j.pocean.2026.103690","DOIUrl":"10.1016/j.pocean.2026.103690","url":null,"abstract":"<div><div>The highly energetic East Australian Current (EAC) System is characterized by dynamic frontal zones that form between the EAC jet and its eddy field. Submesoscale processes at these fronts are critical for lateral and vertical mixing, heat and nutrient flux, and biomass increase and export, but are poorly characterized because in situ fine-scale observational data are lacking. Here, we quantify and contrast the kinematic properties of 13 fronts observed in different dynamical regions of the EAC System using high-resolution data from a dedicated shipboard experiment. We show evidence of strain-driven frontogenesis at most fronts, leading to subduction of colder surface waters rich in oxygen and Chl-a. However, strong surface strain or temperature gradients do not always lead to strong biomass subduction. EAC fronts are associated with relatively shallow subduction depths, likely due to strong stratification of surface waters, in contrast to deep-reaching fronts observed in dipole jets between counter-rotating eddies. We reveal that mesoscale context and frontal structure critically govern vertical exchange and vertical transport of biogeochemical tracers, with the greatest percentage of depth-integrated Chl-a below the euphotic layer (75%) in fronts at dipole jets, associated with downward transport of biomass due to ageostrophic motion. This work demonstrates the diversity of fronts in a dynamic, oligotrophic Western Boundary Current and highlights the essential role of frontal processes in nutrient cycling and carbon export. These results illustrate the need for high-resolution observations and models to accurately estimate biogeochemical processes and carbon fluxes across fronts in a Western Boundary Current System.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"243 ","pages":"Article 103690"},"PeriodicalIF":3.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146209819","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":"Integrative taxonomy of Mesosignidae Schultz, 1969 (Crustacea, Malacostraca) from North Pacific trenches: new species description and biogeographic insights from morphology, mtDNA, and proteomics","authors":"Andreas Kelch ,&nbsp;Laura Spies ,&nbsp;Davide Di Franco ,&nbsp;Maria A. Nilsson ,&nbsp;Sven Rossel ,&nbsp;Pedro Martinez Arbizu ,&nbsp;Anja Rauh ,&nbsp;Heiko Stuckas ,&nbsp;Stefanie Kaiser ,&nbsp;Angelika Brandt","doi":"10.1016/j.pocean.2026.103682","DOIUrl":"10.1016/j.pocean.2026.103682","url":null,"abstract":"<div><div>Submarine deep-sea topography − comprising trenches, ridges, and abyssal plains − functions as a semi-permeable barrier to dispersal. Brooding isopods represent an ideal model for investigating how such features shape species divergence. Here, we applied an integrative framework − combining detailed morphological analyses, a mitochondrial marker (COI), and proteomic fingerprinting using MALDI-TOF MS − to delimit species and elucidate phylogeographic patterns in the deep-sea isopod family Mesosignidae Schulz, 1969 across the Aleutian Trench (AT) and the Kuril-Kamchatka Trench (KKT). Initial attempts to amplify COI with universal primers consistently failed; in response, we designed and validated <em>Kurilosignum</em>-specific primers, achieving ∼ 81 % sequencing success and markedly expanding our genetic dataset. Proteomic profiles corroborated the molecular species clusters, validating this first application of proteomic fingerprinting in Mesosignidae. Molecular analyses revealed four cryptic species within the material morphologically identified as <em>Kurilosignum</em> sp., three confined to the AT and one to the KKT. Patterns of haplotype sharing of one <em>Kurilosignum</em> lineage across abyssal sites north and south of the AT indicate recent gene flow, while abyssal and hadal populations suggest limited vertical connectivity with a divergence of 4.5 %. The AT seems to act as a semi-permeable barrier: <em>Kurilosignum</em> species traverse abyssal plains, whereas species of <em>Japanosignum</em> remains restricted to the southern slope of the AT; however, the small sample size requires additional collections for confirmation. In addition, we formally describe <em>Kurilosignum cardui</em> Kelch &amp; Spies sp. nov. − the second species to be described from the genus − from abyssal depths of the AT. The discovery highlights hidden diversity within a small, low-abundance taxon and demonstrates the power of an integrative framework for resolving taxonomy and biogeography in elusive deep-sea lineages.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"243 ","pages":"Article 103682"},"PeriodicalIF":3.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146001427","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":"Species dispersal and community assembly facing the Atlantic meridional Overturning circulation","authors":"Everton Giachini Tosetto ,&nbsp;Christophe Lett ,&nbsp;Sigrid Neumann-Leitão ,&nbsp;Ariane Koch-Larrouy ,&nbsp;Nicolas Barrier ,&nbsp;Alex Costa da Silva ,&nbsp;Ramilla Assunção ,&nbsp;Camila Artana ,&nbsp;Alina Nathanael Dossa ,&nbsp;Guillaume Morvan ,&nbsp;Arnaud Bertrand","doi":"10.1016/j.pocean.2026.103705","DOIUrl":"10.1016/j.pocean.2026.103705","url":null,"abstract":"<div><div>The strong advective circulation governing western boundary current systems poses challenges to coastal organism to retain their planktonic larvae and assembly in local communities. However, instabilities around the predominant current, generating features such as eddies, may increase retention and thereby enhance local diversity. Here, we have investigated this hypothesis through high-resolution (1/36°) community-based Lagrangian dispersal modelling experiments conducted along the Pernambuco Plateau and adjacent open ocean off Brazil, which is part of the strong Atlantic Meridional Overturning Circulation. In the highly advective north portion of the plateau, we found that retention is reduced and advection from open ocean is intense. Under such circumstances, the assembly of local communities is likely driven by mass effect, which results in homogeneous communities with reduced biodiversity. In contrast, in the south portion of the plateau, eddies and meanders associated with the interaction of the currents with the plateau topography and the seasonal variability of the South Equatorial Current bifurcation increase local retention and reduce advection from open ocean. In such conditions, both, species sorting and mass effect assembling archetypes, likely drive the distinct and rich biodiversity inhabiting the region to the south of the plateau. The dispersal patterns obtained from the Lagrangian experiments align with the known spatial patterns of biodiversity distribution along the Tropical Southwestern Atlantic and provide important insights for regions and taxa for which knowledge is limited or absent. These results also provide elements for the proper definition of biodiversity conservation and management strategies and for a better understanding of the processes regulating community assembly in highly advective systems around the globe.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"243 ","pages":"Article 103705"},"PeriodicalIF":3.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147360455","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":"Challenging one-way fish modelling: two-way coupling reveals critical marine ecosystem dynamics","authors":"Helen R. Powley ,&nbsp;Rebecca Millington ,&nbsp;Yuri Artioli ,&nbsp;Robert J. Wilson ,&nbsp;Jorn Bruggeman","doi":"10.1016/j.pocean.2026.103701","DOIUrl":"10.1016/j.pocean.2026.103701","url":null,"abstract":"<div><div>Anthropogenic stressors such as climate change and fishing are altering marine ecosystem dynamics. To understand and predict how marine foodwebs are changing, both top-down and bottom-up trophic dynamics need to be included in our model systems. A common simplification employed is a one-way coupled modelling approach, where results of lower trophic level (LTL) (plankton) models are used to drive fish models, but feedbacks due to fish predation are not applied to the LTL model. Thus, fish do not perceive the resulting reduction in prey biomass, limiting the predictive capacity of the models. Here we have implemented innovative two-way coupling between an LTL model, ERSEM, and the community size spectrum fish model configuration of MIZER, to produce a complete model chain from photons to fisheries. The model is used to investigate the impact of two-way coupling on the North West European Shelf ecosystem. Within the two-way coupled model, clearance rates of fish and mortality rates of mesozooplankton had to be reduced, highlighting limitations of parameterisations within one-way coupled models. Mesozooplankton was the most sensitive group to two-way coupling with a 17% decrease in biomass across the shelf in addition to changes in phenology. Furthermore, two-way coupling decreased carbon cycling across the shelf driven by the top-down pressures on mesozooplankton reducing their production of organic matter and weakening the microbial loop. This impacted the ocean’s ability to absorb atmospheric carbon and consequently has climate change implications. Two-way coupled fisheries models should therefore be considered in the next generation of earth system models.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"243 ","pages":"Article 103701"},"PeriodicalIF":3.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147403231","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":"Roles of microzooplankton in the biological carbon pump","authors":"Albert Calbet","doi":"10.1016/j.pocean.2026.103700","DOIUrl":"10.1016/j.pocean.2026.103700","url":null,"abstract":"<div><div>The biological carbon pump (BCP) is a fundamental component of the Earth’s climate system, enabling the transfer of carbon from surface waters to the deep ocean, where it can be sequestered for centuries. While phytoplankton are the primary agents of carbon fixation in the ocean, the fate of that carbon—whether it is remineralized, respired, or exported—hinges critically on the activity of microzooplankton. These small, mostly unicellular heterotrophic protists are key grazers of primary producers and intermediaries in marine planktonic food webs. This review synthesizes recent findings that reveal how microzooplankton influence BCP efficiency through direct and indirect mechanisms: grazing on phytoplankton and detrital particles, respiration and excretion that regenerate nutrients and carbon dioxide in surface waters, and participation in or interaction with diel vertical migration processes. I highlight how their roles vary across environmental gradients and how size-structured trophic cascades and community shifts affect carbon export potential. Depending on the dominant microzooplankton group, grazing activity may reduce export efficiency by retaining carbon in surface waters, whereas vertical migration—although less studied among protists—may actively contribute to deep ocean carbon transport. By examining field observations, mesocosm experiments, and ecosystem models, I attempt to offer a comprehensive understanding of how microzooplankton act as both gatekeepers and facilitators of the ocean’s carbon economy. Recognizing their dualistic nature—retainers of carbon and subtle agents of sequestration—is vital for improving global biogeochemical models and predictions of carbon–climate feedbacks.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"243 ","pages":"Article 103700"},"PeriodicalIF":3.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146160576","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":"Opposite latitudinal biodiversity gradient in the open ocean generated by transition zones: Insights from fish distribution in the Northwest Pacific","authors":"Yuan Lin ,&nbsp;Zeshu Yu ,&nbsp;Sk Istiaque Ahmed ,&nbsp;Xueding Wang ,&nbsp;Tomihiko Higuchi ,&nbsp;Itsuka Yabe ,&nbsp;Marty Kwok-Shing Wong ,&nbsp;Sachihiko Itoh ,&nbsp;Eisuke Tsutsumi ,&nbsp;Hiroaki Saito ,&nbsp;Kosei Komatsu ,&nbsp;Atsushi Tsuda ,&nbsp;Yusuke Kawaguchi ,&nbsp;Eitarou Oka ,&nbsp;Hajime Obata ,&nbsp;Yuki Minegishi ,&nbsp;Hideki Fukuda ,&nbsp;Jun Inoue ,&nbsp;Susumu Hyodo ,&nbsp;Shin-ichi Ito","doi":"10.1016/j.pocean.2026.103685","DOIUrl":"10.1016/j.pocean.2026.103685","url":null,"abstract":"<div><div>In this study, we used five years of environmental DNA (eDNA) data to examine the geographic distribution and community structure of marine fish in the Northwestern Pacific. We identified key environmental drivers influencing fish community composition, focusing on dynamic transition zones such as coastal–offshore interfaces and the Kuroshio–Oyashio transition zone. Using eDNA samples and environmental data from 2018 to 2023, we analyzed fish community structure with high-throughput sequencing. Hierarchical clustering, non-metric multidimensional scaling (NMDS), diversity index estimation, and generalized additive models (GAMs) were employed to evaluate the impact of ecological factors on community composition and diversity patterns. Clustering showed six distinct fish communities based on the presence/absence data. Species accumulation curves indicated highest diversity in the coastal region of the Subtropical Gyre, followed by the East China Sea and the Kuroshio–Oyashio transition zone. NMDS revealed that salinity and seafloor depth strongly influenced community composition, in addition to surface temperature, chlorophyll-a, and dissolved oxygen. GAM results showed that surface temperature, seafloor depth, and vertical temperature gradients primarily drove the spatial variation in species richness, with temperature showing a nonlinear effect. Our findings revealed that fish biodiversity tends to be higher in cooler regions and shallower depths, with biodiversity hotspots occurring in coastal–offshore frontal zones and the Kuroshio–Oyashio transition zone. These hotspots formed bimodal diversity peaks relative to temperature, and a depth-related peak near the continental slope–trench transition. This study supports efforts toward sustainable marine ecosystem development and biodiversity conservation in dynamic oceanic systems.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"243 ","pages":"Article 103685"},"PeriodicalIF":3.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146033594","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":"Diatom community response to high and low iron upwelling plumes in the California current system","authors":"Sveinn V. Einarsson ,&nbsp;Kimberly Powell ,&nbsp;Claire Till ,&nbsp;Tyler Coale ,&nbsp;P. Dreux Chappell","doi":"10.1016/j.pocean.2026.103703","DOIUrl":"10.1016/j.pocean.2026.103703","url":null,"abstract":"<div><div>Diatoms are important primary producers, accounting for most of the oceanic production and carbon export relative to other photosynthetic eukaryotes. There are important differences among diatom species that enable them to proliferate in different environments. Some have nutrient storage capabilities or lower nutrient quotas suited for oligotrophic oceans. Bloom-forming diatoms are typically found in nutrient-rich coastal waters where they respond quickly to nutrient pulses and can influence biogeochemical cycling in the ocean after blooms. As many physiological differences affect biomass and export, it is important to better understand how physical and chemical parameters influence diatom community composition, especially in dynamic upwelling environments. Examining diatom community responses to upwelling can be challenging, as it is difficult to capture and track upwelling waters from initiation. Here, we present the diatom community composition from two physically and chemically distinct upwelling plumes in the California Current System (CCS), determined using 18S rDNA sequencing, to test the hypothesis that iron (Fe) influences upwelling diatom communities. Diatom community composition, dFe, and dFe:nitrate (NO₃^–) were all significantly different in the two upwelling plumes. There was higher fluorescence and higher relative abundance of bloom-forming <em>Chaetoceros</em> at the start of the upwelling transect with higher initial dFe. Interestingly, the complex physics of the CCS appeared to influence the dispersion of upwelling-induced diatom communities, with the same <em>Chaetoceros</em> species abundant after passing through a high velocity jet in the lower initial dFe upwelling transect. We conclude with a discussion of possible implications for future predictions of diatom proliferation, transport, and carbon export in the CCS.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"243 ","pages":"Article 103703"},"PeriodicalIF":3.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146778198","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":"Effect of oceanographic variables and space-time factors on the density of Peruvian anchovy (Engraulis ringens): An approach with GAMLSS","authors":"Oswaldo Flores ,&nbsp;Robert Rigby ,&nbsp;Marceliano Segura ,&nbsp;Jesús Ledesma ,&nbsp;Carlos Paulino ,&nbsp;Germán Chacón ,&nbsp;Juan Valles","doi":"10.1016/j.pocean.2026.103688","DOIUrl":"10.1016/j.pocean.2026.103688","url":null,"abstract":"<div><div>This study examines how environmental and spatiotemporal factors modulate the acoustic density (area backscattering coefficient, s_A) of the Peruvian anchoveta (<em>Engraulis ringens</em>), using data from 25 IMARPE surveys conducted between 2007–2017. Given the semicontinuous nature of s_A (characterized by an excess of zeros and strong positive skewness) GAMLSS models with zero-adjusted Box–Cox t and Generalized Inverse Gaussian distributions (ZABCTo and ZAGIG) were fitted. These models allow s_A to be analyzed in its original scale while jointly estimating the location (<em>μ</em>), scale (<em>σ</em>), skewness (<em>ν</em>), kurtosis (<em>τ</em>), and probability of absence (<em>π</em>_<em>0</em>) parameters, thus providing a complete distributional characterization of aggregation processes.</div><div>The results revealed a consistent spatial structure, with the highest densities occurring within 40 nm of the coast and between 6°–15°S, under salinities of 33.75–35.2 PSU, sea surface temperatures of 14–25 °C, and dissolved oxygen &gt; 5 mL L⁻¹. Modeling s_A on its original scale uncovered nonlinear environmental thresholds, diel variability, and changes in spatial heterogeneity that are not detected when using Gaussian and Tweedie GAMs or GAMLSS models based on logarithmic transformations. Seasonal models further showed that upwelling intensity, ENSO-related anomalies, and short-term fluctuations influence not only the magnitude and dispersion of s_A but also reflect the extreme densities that characterize anchoveta aggregation dynamics.</div><div>By demonstrating that distributional modeling of s_A without transformations preserves ecological information that is lost under traditional approaches, this study provides a robust statistical basis for interpreting aggregation responses in the highly dynamic upwelling system of the Humboldt Current.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"243 ","pages":"Article 103688"},"PeriodicalIF":3.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146134965","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}