First assessment of Atlantic open ocean Sargassum spp. metal and metalloid concentrations
Over the last decade, increasing proliferations of Atlantic Sargassum populations have led to massive beaching with disastrous environmental consequences. This study is a preliminary assessment of open ocean Sargassum spp. element concentration to assess their potential contribution on coastal ecosystems. Sargassum spp. samples from seven sites, collected along a transect from the center of the Atlantic Ocean to near the coast of Martinique (French West Indies), were analyzed to determine their potential metal and metalloid contamination. Mean element concentrations from the Sargassum spp. samples were ranked in the following descending order: As > Fe > Mn > Al > Zn > V > Ni > Cu > Cr > Cd > Hg. Element concentrations are relatively low compared to previous results of beached Sargassum spp. except for As that need to be carefully considered before reusing Sargassum spp.
(Environmental Science and Pollution Research. vol. 29, n° 0944-1344, pp. 17606-17616, 13/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, ISYEB, MNHN, EPHE, PSL, SU, CNRS, UA
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
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 Unpublished results from a field campaign carried out in early 2021 under storm wave conditions are presented and compared with the predictions from a state-of-the-art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
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
Lateglacial and Holocene sedimentary dynamics in northwestern Baffin Bay as recorded in sediment cores from Cape Norton Shaw Inlet (Nunavut, Canada)
The physical, sedimentological, mineralogical and elemental geochemical properties of sediment cores AMD1803-02BC and 01PC from the Cape Norton Shaw Inlet were investigated to reconstruct glacial sediment discharges from southeastern Manson Icefield and document the impact of ice–ocean interactions on the sediment dynamics and opening of the North Water Polynya (NOW) in northwestern Baffin Bay since the last deglaciation. Laminated glaciomarine sediments rich in quartz and feldspar are observed prior to 11 cal. ka BP and were probably deposited by hyperpycnal currents triggered by the local retreat of the southern margin of the Innuitian Ice. Detrital proxies suggest that Early Holocene sediment dynamics were mainly influenced by sea ice and iceberg rafting and meltwater discharges related to the deglaciation of eastern Smith (~11 to 10.65 cal. ka BP) and Jones (~10.7 cal. ka BP) sounds. This also provides an upper limit to the timing of formation of the NOW. The high detrital carbonate contents during 8.8 to 6.6 cal. ka BP confirm that enhanced carbonate-rich sediment export from Nares Strait to northern Baffin Bay occurred during and after the deglaciation of Kennedy Channel (8.8 to 8.2 cal. ka BP). Canadian Shield sediment inputs have dominated since 6.6 cal. ka BP, indicating that sedimentation is mainly influenced by Cape Norton Shaw glacier discharges. The lower level of sedimentation recorded in core 01PC during the Middle to Late Holocene suggests an accelerated landward retreat of the Cape Norton Shaw glaciers in response to warmer marine conditions. During the Neoglacial period, higher sedimentation rates and detrital proxies in the cores suggest increased glacial erosional processes, probably associated with the long-term declines in boreal summer insolation and glacier growth. Finally, mineralogical and grain-size data in core 02BC support the idea that increased Arctic atmospheric temperatures have had an important influence on the glacial dynamics during the industrial period.
(Boreas. vol. 51, n° 0300-9483, pp. 532-552, 13/04/2026)
LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, ISMER, UQAR
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
Experimental Exposure to Tebuconazole Affects Metabolism and Body Condition in a Passerine Bird, the House Sparrow ( Passer domesticus )
Triazole compounds are among the most widely used fungicides in agroecosystems to protect crops from potential fungal diseases. Triazoles are suspected to have an impact on nontarget species due to their interactions with nonfungal sterol synthesis, and wild birds are likely to be contaminated by triazole fungicides because many of them live in agroecosystems. We experimentally tested whether exposure to environmental concentrations of a triazole could alter key integrative traits (metabolic rates and body condition) of an agroecosystem sentinel species, the house sparrow (Passer domesticus). Wild-caught adult sparrows were maintained in captivity and exposed (exposed group) or not (control group) for 7 continuous months to tebuconazole through drinking water. The metabolic rates of exposed and control sparrows were then measured at two different temperatures (12 °C and 25 °C), which correspond, respectively, to the thermoregulation and thermoneutrality temperatures of this species. We found that exposed sparrows had lower resting metabolic rates (i.e., measured at thermoneutrality, 25 °C) than controls. However, the thermoregulatory metabolic rates (i.e., measured at 12 °C) did not differ between exposed and control sparrows. Although the body mass and condition were not measured at the beginning of the exposure, sparrows at the time of the metabolic measurements 7 months after the onset of such exposure had a higher body condition than controls, supporting further the idea that tebuconazole affects metabolic functions. Our study demonstrates for the first time that the use of tebuconazole can alter metabolism and could potentially lead to adverse effects in birds
(Environmental Toxicology and Chemistry. vol. 41, n° 0730-7268, pp. 2500-2511, 13/04/2026)
CEBC, ULR, CNRS, INRAE, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LCE, CNRS, UFC, UBFC
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