Cross‐Shore Distribution of the Wave‐Induced Circulation Over a Dissipative Beach Under Storm Wave Conditions
This study explores the spatial distribution and the driving mechanisms of the wave-induced cross-shore flow within the shoreface and surf zone of a dissipative beach. Unpublished results from a field campaign carried out in early 2021 under storm wave conditions are presented and compared with the predictions from a state-of-the-art phase-averaged three-dimensional circulation modeling system based on the vortex force formalism. Under storm wave conditions, the cross-shore flow is dominated by a strong seaward-directed current in the lower part of the water column. The largest current velocities of this return current are located in the surf zone, where the dissipation by depth-induced breaking is most intense, but offshore-directed velocities up to 0.25 m/s are observed as far as 4 km from the shoreline (≃12 m-depth). Numerical experiments further highlight the key control exerted by non-conservative wave forces and wave-enhanced mixing on the cross-shore flow across a transition zone, where depth-induced breaking, whitecapping, and bottom friction all significantly contribute to the wave energy dissipation. Under storm conditions, this transition zone extended almost 6 km offshore and the cross-shore Lagrangian circulation shows a strong seaward-directed jet in the lower part of the water column, whose intensity progressively decreases offshore. In contrast, the surf zone edge appears clearly delimited under fair weather conditions and the seaward-directed current is weakened by a near bottom shoreward-directed current associated with wave bottom streaming in the shoaling region, such that the clockwise Lagrangian overturning circulation is constrained by an additional anti-clockwise overturning cell at the surf zone edge
(Journal of Geophysical Research. Oceans. vol. 127, n° 2169-9275, pp. e2021JC018108, 13/04/2026)
LIENSs, INSU - CNRS, ULR, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
The underestimated effects of nanoplastics on living organisms
Scientific Sessions S-31 | Micro- and nanoplastics (MNPs) and human health
(Toxicology Letters. vol. 368, n° 0378-4274, pp. S72-S72, 13/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, GR, UR, INSU - CNRS, CNRS, ULaval, INSU - CNRS, CNRS
Identification of Atlantic water inflow on the north Svalbard shelf during the Holocene
Nordaustlandet is located in the northeastern part of the Svalbard archipelago, within the northernmost reach of the West Spitsbergen Current. This current transports Atlantic water to the Arctic Ocean along the western and northern Svalbard margins. This region is well-suited for reconstructing the history of changing Atlantic water inflow to the Arctic Ocean. We studied the marine sediment core HH12-04-GC from Rijpfjorden. Benthic foraminiferal assemblages and sedimentological data are combined to reconstruct the palaeoenvironment of the fjord from the end of the last local deglaciation to the late Holocene. The local deglaciation, between 11.3 and 10.6 cal ka bp, was dominated by active glacier calving processes, associated with a strong inflow of Atlantic water. This led to the establishment of glaciomarine conditions. The Holocene was initially characterised by a relatively stable and warm environment associated with a strong contribution of Atlantic water. Glaciomarine influence progressively decreases after 9.7 cal ka bp and the Atlantic water contribution increases. The late Holocene displayed a similar environment to today, with the influence of glaciomarine conditions and limited Atlantic water inflow. These results confirm that Atlantic water inflows made a continuous contribution to northern Nordaustlandet throughout the postglacial period.
(Journal of Quaternary Science. vol. 37, n° 0267-8179, pp. 86-99, 13/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UNIS
Evidence of the largest Late Holocene mountain glacier extent insouthern and southeastern Greenland during the middle Neoglacial fromBe-10 moraine dating
(Boreas. vol. 51, n° 0300-9483, pp. 61--77, 13/04/2026)
LGP, UP1, UPEC UP12, CNRS, CEREGE, IRD, AMU, CdF (institution), INSU - CNRS, CNRS, INRAE, UP1, PANGEA Research Centre, BEES, UNSW, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Progress towards an international comparison of river sediment pollution: Key factors influencing metal concentrations along seven Western European Rivers (1945-2020)
Since 60 years, a large amount of data has been acquired to survey river sediment quality, especially concerning regulatory trace metals such as Cd, Cr, Cu, Hg, Ni, Pb, and Zn. Large-scale syntheses are still rare and show some limits to assess the effectiveness of public regulations and the river systems' resilience. Based on a sediment contamination database comprising more than 12,000 samples, we propose a first attempt to decipher spatio-temporal trends of metal contamination along seven major rivers in Western Europe (Garonne-Lot, Loire, Meuse Rhine, Rhone, Scheldt and Seine Rivers). Facing heterogeneous sampling and analytical methods on different sediment matrices (bed and flood deposits – BFD, suspended particulate matter – SPM, dated sediment cores – DSC), this work investigates the effect of analytical protocols, spatial and temporal factors on metal concentration trends. At a large scale, an increase in metal concentrations (especially for Cd, Pb and Zn) is reported along most of the investigated rivers. It appears closely related to major urban-industrial hotspots (Paris-Rouen corridor on the Seine River, Bonn-Duisburg corridor on the Rhine River, etc.) and to the geology of each watershed, both influencing the regional sediment quality. Former mining and metallurgical districts, generally located in crystalline areas, also caused high metal concentrations on the long term (Upper Loire River, Middle Meuse River, Lot River). A global decrease of metal concentrations is observed in all river sections since the 1960s-1970s onwards, in response to European and national regulations, and to socio-economical changes affecting urban-industrial areas. The high influence of the location of the samples along the rivers and the decade of sampling is confirmed by a Factor Analysis of Mixed Data (FAMD). Secondary factors such as the influence of the sediment matrix type (BFD, SPM and DSC) and the different digestion procedures prior to elemental analysis also explained significant differences for Cr, Cd, Cu, Pb, or Zn, although this can also be locally balanced by the substratum (i.e. for alkaline rivers). This approach points out the limitations of the available data, particularly regarding the need of regional geological backgrounds and the more systematic acquisition of ancillary data such as grain-size and TOC. It also provides critical clues to intercompare metal sediment pollution in rivers at large spatial and temporal scales worldwide.
(13/04/2026)
EVS, ENS de Lyon, Mines Saint-Étienne MSE, IMT, UL2, UJML, INSA Lyon, INSA, UJM, ENTPE, ENSAL, CNRS, ALLHiS, UJM, GéHCO, UT, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, M2C, UNICAEN, NU, INSU - CNRS, UNIROUEN, NU, CNRS, LIVE, UNISTRA, CNRS, ITES, ENGEES, UNISTRA, INSU - CNRS, CNRS, LEHNA, UCBL, ENTPE, CNRS, ENTPE, ENTPE
Caractérisation de la contamination métallique des sédiments dans les masses d’eau de la métropole bordelaise et analyses préliminaires de son effet sur la diversité piscicole
Dans un contexte d’une urbanisation croissante et de pressions anthropiques multiples (industrielles, domestique, agricole, trafic routier), les milieux aquatiques sont le réceptacle de grandes quantités de contaminants dont les éléments traces métalliques (ETM), historiques (e.g. Plomb [Pb], Zinc [Zn]) ou émergeants (e.g. Terres Rares REE). L’objectif général du travail s’appuie sur deux postulats : 1) La matrice sédimentaire est un bon intégrateur de la pollution engendrée à l’échelle des bassins versants dont les ETM pourraient être un bon proxy ; 2) Les poissons sont de bons indicateurs des perturbations anthropiques. Couplant deux postulats, cette étude vise à établir les relations potentielles entre la présence d’ETM dans les hydrosystèmes et la richesse et composition spécifique des peuplements de poissons dans les environnements urbains et péri-urbains de Bordeaux Métropole (Nouvelle Aquitaine, SO France). Pour cela, des pêches électriques ont été effectuées en 2018 et 2019, complétées par des prélèvements de sédiments. Une caractérisation physico-chimique des sédiments a été réalisée durant ce stage en déterminant la texture (granulométrie), les teneurs en Carbone Organique Total (COT) et en ETM sur la fraction totale (minéralisation triacide) et la fraction chimiquement disponible (digestion HCl 1M). Les concentrations brutes et normalisées (s’affranchissant de l’effet granulométrique) ont été comparées au bruit de fond géochimique régional et à des indices écotoxicologiques (TEC/PEC, Métox). Les analyses statistiques n’ont pas révélé de différence significative entre les sites, habitats et années. L’analyse préliminaire des relations entre les ETM et la composition spécifique des communautés de poissons n’a pas mis en évidence de lien statistique significatif entre les deux jeux de données. Les raisons possibles de cette absence de corrélation sont discutées, en particulier le rôle d’autres facteurs structurants négligés (e.g. physico-chimique, non intégration des ETM dissous ou de variables d’intégrité physique des cours d’eaux) et seront à investiguer pour de prochaines campagnes.
(pp. 56, 13/04/2026)
UR EABX, INRAE, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Impact of nickel mining in New Caledonia on marbled eels Anguilla marmorata
New Caledonia is particularly affected by nickel open pit mining activities because of the presence of ultramafic soils rich in metal trace elements. The nickel particles dispersed by atmospheric transport and soil erosion during the excavation of nickel will end up by deposition or leaching in aquatic ecosystems where they may be bioaccumulated by living organisms in the rivers downstream the mines. Despite alarming freshwater metals concentrations, no study investigated the level of their bioaccumulation in eels living downstream mining sites, and if high bioaccumulation levels occur, the potential consequences on eel's health. The aim of this study was to determine how eels Anguilla marmorata are impacted in situ by metal concentrations issued from mining activity by measuring: morphometric parameters; metal concentrations in tissues and organs and transcription levels of target genes encoding proteins involved in several metabolic key functions. Among organs, liver was found to be the most affected by mining with average nickel concentrations of 5.14 mg/kg versus 1.63 mg/kg for eel liver away from mines leading to dysregulation of numerous genes involved in oxidative stress, DNA repair, apoptosis, reproduction and both lipid and mitochondrial metabolisms. This study should allow us to define in an integrated way if metals released by mining activities influence metals bioaccumulation in eels and induce biological effects.
(Journal of Hazardous Materials. vol. 436, n° 0304-3894, pp. 129285, 13/04/2026)
CRCTB, UB, CHU Bordeaux, INSERM, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, ISEA, UNC, UMS POREA, INSU - CNRS, CNRS, INRAE
Passive Sampling as a Tool to Assess Atmospheric Pesticide Contamination Related to Vineyard Land Use
The massive use of pesticides in agriculture has led to widespread contamination of the environment, particularly the atmospheric compartment. Thirty-six pesticides, most used in viticul-ture, were monitored in ambient air using polyurethane foams as passive air samplers (PUF-PAS). Spatiotemporal data were collected from the samplers for 10 months (February–December 2013), using two different sampling times (1 and 2 months) at two different sites in a chateau vineyard in Gironde (France). A high-volume active air sampler was also deployed in June. Samples were extracted with dichloromethane using accelerated solvent extraction (ASE) (PUFs from both passive and active) or microwave-assisted extraction (MAE) (filters from active sampling). Extracts were analyzed by both gas and liquid chromatography coupled with tandem mass spectrometry. A total of 23 airborne pesticides were detected at least once. Concentrations in PUF exposed one month ranged from below the limits of quantification (LOQs) to 23,481 ng PUF−1. The highest concentrations were for folpet, boscalid, chlorpyrifos-methyl, and metalaxyl-m—23,481, 17,615, 3931, and 3324 ng PUF−1. Clear seasonal trends were observed for most of the pesticides detected, the highest levels (in the ng m−3 range or the µg PUF−1 range) being measured during their application period. Impregnation levels at both sites were heterogeneous, but the same pesticides were involved. Sampling rates (Rs) were also estimated using a high-volume active air sampler and varied significantly from one pesticide to another. These results provide preliminary information on the seasonality of pesticide concentrations in vineyard areas and evidence for the effectiveness of PUF-PAS to monitor pesticides in ambient air. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.
(Atmosphere. vol. 13, n° 2073-4433, pp. 504, 13/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Atmospheric Nitrous Acid Measurement in the French Landes Forest
(ACS Earth and Space Chemistry. vol. 6, n° 2472-3452, pp. 25-33, 13/04/2026)
IRCELYON-CARE, IRCELYON, UCBL, INC-CNRS, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LVEEM, UCA [2017-2020], CERI EE - IMT Nord Europe, IMT Nord Europe, IMT, IRCELYON, UCBL, INC-CNRS, CNRS
Bi-decadal changes in nutrient concentrations and ratios in marine coastal ecosystems: The case of the Arcachon bay, France
Large amounts of nutrients have been released to the coastal ecosystems during the 20th century. Since then, management policies have been implemented and these amounts decreased in the economically developed countries. We examined the bi-decadal changes in nutrients (nitrate + nitrite, ammonium, orthophosphate and silicic acid) in the Arcachon bay, a semi-enclosed lagoon that hosts one of the largest but declining seagrass meadow in Europe. Seven sites have been sampled for nutrients and biogeochemical parameters during twenty years at low and/or high tide. In addition, continental and climatic data as well as hydro-climatic indices were used. Dynamic linear models were used to assess the bi-decadal changes in nutrient concentrations and ratios, their seasonality, and the bi-decadal changes of their potential drivers. Partial least square path modeling were used to investigate the relationships between potential abiotic drivers and nutrients. During the study period, the concentration of N and Si nutrients increased whereas the concentration of orthophosphate decreased, leading to deep changes in nutrient ratios. Clear relationships between abiotic drivers (local climate, continental inputs and the bay hydrodynamism) and N, P and Si nutrients were highlighted. However, the bi-decadal change in nutrient concentrations and ratios was mainly ascribed to the seagrass meadow decline through direct (less nutrient consumption) and indirect (increase in phytoplankton biomass) processes. Changes in temperature and wind direction may also influenced the nutrients concentrations through processes of remineralisation and flushing time, respectively. This study illustrates (1) the top-down control of seagrass on the nutrients concentrations and stoichiometry, and (2) the competition between primary producers (seagrass vs phytoplankton) for their nutrients resource.
(Progress in Oceanography. vol. 201, n° 0079-6611, 13/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, IFREMER