Tellurium behaviour in a major European fluvial–estuarine system (Gironde, France): fluxes, solid/liquid partitioning and bioaccumulation in wild oysters
The environmental behaviour of tellurium is poorly understood. We investigate the transport of tellurium in both dissolved and particulate forms from the river watershed to the Gironde Estuary, where a 30-year historical record provides insight on tellurium bioaccumulation in wild oysters. These results constitute the first comprehensive study on natural tellurium behaviour in a major fluvial-estuarine system, information essential for predictive modelling of tellurium risk assessment. AbstractTellurium (Te) is a technology critical element (TCE) with largely unknown environmental behaviour, especially in continent-ocean interface systems. The unknown behaviour results from the lack of studies in aquatic environments and from analytical challenges limiting the determination of its naturally low (ultra-trace) environmental levels. We performed a comprehensive study of Te in the Lot–Garonne–Gironde fluvial–estuarine system to better understand seasonal variations, solid/liquid partitioning (Kd), gross fluxes, estuarine dynamics, and transfer to wild oysters at the estuary mouth. A temporal record (2014–2017) of dissolved (Ted) and particulate (Tep) Te concentrations at five sites in the Lot–Garonne River system shows little differences between sites, with average ~0.9ngL−1 and ~50µgkg−1 respective concentrations. Watershed Ted and Tep follow parallel seasonal patterns, which result in constant partitioning (log10 Kd ~4.75Lkg−1), with constant annual gross dissolved fluxes (~15.0kgy−1) and variable gross particulate fluxes (from 6.50 to 140kgy−1) entering the Gironde Estuary. Estuarine reactivity in contrasting hydrological conditions (from flood to drought) suggest that grain-size effects and/or estuarine hydrological residence times strongly affect Tep behaviour. Historical records (1984–2017) of Te in wild oysters at the estuary mouth vary from 1.33 to 2.89µgkg−1 dry weight (d.w.), without any clear long-term trend. This study provides rare knowledge on Te environmental dynamics in aquatic systems, and suggests that, although no current anthropogenic sources were identified in the economically developed Lot-Garonne-Gironde fluvial-estuarine system, there is a non-negligible bioaccumulation in wild oysters at the estuary mouth.
(Environmental Chemistry. vol. 16, n° 1448-2517, pp. 229, 28/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
The impact of possible decadal-scale cold waves on viticulture over Europe in a context of global warming
A comprehensive analysis of all the possible impacts of future climate change is crucial for strategic plans of adaptation for viticulture. Assessments of future climate are generally based on the ensemble mean of state-of-the-art climate model projections, which prefigures a gradual warming over Europe for the 21st century. However, a few models project single or multiple O(10) year temperature drops over the North Atlantic due to a collapsing subpolar gyre (SPG) oceanic convection. The occurrence of these decadal-scale "cold waves" may have strong repercussions over the continent, yet their actual impact is ruled out in a multi-model ensemble mean analysis. Here, we investigate these potential implications for viticulture over Europe by coupling dynamical downscaled EUR-CORDEX temperature projections for the representative concentration pathways (RCP)4.5 scenario from seven different climate models-including CSIRO-Mk3-6-0 exhibiting a SPG convection collapse-with three different phenological models simulating the main developmental stages of the grapevine. The 21st century temperature increase projected by all the models leads to an anticipation of all the developmental stages of the grapevine, shifting the optimal region for a given grapevine variety northward, and making climatic conditions suitable for high-quality wine production in some European regions that are currently not. However, in the CSIRO-Mk3-6-0 model, this long-term warming trend is suddenly interrupted by decadal-scale cold waves, abruptly pushing the suitability pattern back to conditions that are very similar to the present. These findings are crucial for winemakers in the evaluation of proper strategies to face climate change, and, overall, provide additional information for long-term plans of adaptation, which, so far, are mainly oriented towards the possibility of continuous warming conditions.
(Agronomy. vol. 9, n° 2073-4395, pp. 1-22, 28/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, AGROCLIM, INRA, UMR EGFV, INRA, UB, Bordeaux Sciences Agro
Temporal variability of lagoon–sea water exchange and seawater circulation through a Mediterranean barrier beach
The subterranean flow of water through sand barriers between coastal lagoons and the sea, driven by a positive hydraulic gradient, is a net new pathway for solute transfer to the sea. On the sea side of sand barriers, seawater circulation in the swash‐zone generates a flux of recycled and new solutes. The significance and temporal variability of these vectors to the French Mediterranean Sea is unknown, despite lagoons constituting ~ 50% of the coastline. A one‐dimensional 224Raex/223Ra reactive‐transport model was used to quantify water flow between a coastal lagoon (La Palme) and the sea over a 6‐month period. Horizontal flow between the lagoon and sea decreased from ~ 85 cm d−1 during May 2017 (0.3 m3 d−1 m−1 of shoreline) to ~ 20 cm d−1 in July and was negligible in the summer months thereafter due to a decreasing hydraulic gradient. Seawater circulation in the swash‐zone varied from 10 to 52 cm d−1 (0.4–2.1 m3 d−1 m−1), driven by short‐term changes in the prevailing wind and wave regimes. Both flow paths supply minor dissolved silica fluxes on the order of ~ 3–10 mmol Si d−1 m−1. Lagoon–sea water exchange supplies a net dissolved inorganic carbon (DIC) flux (320–1100 mmol C d−1 m−1) two orders of magnitude greater than seawater circulation and may impact coastal ocean acidification. The subterranean flow of water through sand barriers represents a significant source of new DIC, and potentially other solutes, to the Mediterranean Sea during high lagoon water‐level periods and should be considered in seasonal element budgets.
(Limnology and Oceanography. vol. 64, n° 0024-3590, pp. 2059-2080, 28/04/2026)
LEGOS, IRD, UT3, Comue de Toulouse, INSU - CNRS, CNES, CNRS, CEREGE, IRD, INRA, AMU, CdF (institution), INSU - CNRS, CNRS, GET, IRD, UT3, Comue de Toulouse, INSU - CNRS, CNES, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, TropWATER, JCU, SBU, SUNY, GEOMAR
Introduction: Special Issue on Coastal Evolution under Climate Change along the Tropical Overseas and Temperate Metropolitan France
This paper presents how major French science-oriented public institutions and Ministry of Higher Education, Research, and Innovation (MESRI) have developed and structured coastal observatories along metropolitan and oversea coastlines in order to better understand the metropolitan and oversea French coastal evolution on a wide range of temporal and spatial scales. Scientific results presented in this special Issue have been obtained in the framework of the resulting DYNALIT / ILICO observatory network.
(Journal of Coastal Research. vol. 88, n° 0749-0208, pp. 1-2, 28/04/2026)
IFREMER, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Analyses préliminaires d'une météorite lunaire NWA XXX
Dans le cadre d’un stage de Master 1 de physique, nous avons utilisé plusieurs techniques d’analyse pour caractériser une météorite potentiellement lunaire NWA XXX (non référencée) ainsi qu’un échantillon de la météorite lunaire NWA 5000. Nous avons comparé les résultats que nous avons obtenus pour la météorite non référencée avec ceux de NWA 5000 ainsi qu’avec les résultats d’études précédentes sur d’autres météorites lunaires. L’interprétation de nos analyses semble confirmer l’origine lunaire de cette météorite non référencée. Elle présente cependant une composition un peu différente des autres météorites lunaires avec un excès en potassium et en sodium. Elle pourrait donc provenir d’une région non encore explorée de La Lune.
(28/04/2026)
UB, LAB, UB, INSU - CNRS, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LEESA, UB, CNRS, PACEA, UB, CNRS, ENSAM
The influence of bottom currents on the Zambezi Valley morphology (Mozambique Channel, SW Indian Ocean): In situ current observations and hydrodynamic modelling
Mixed turbidite-contourite systems can be found in oceans where bottom currents and turbidity currents interact. The Zambezi turbidite system, located in the Mozambique Channel (SW Indian Ocean), is one of the largest sedimentary systems in the world in length and area of the related catchments. The oceanic circulation in the Mozambique Channel is intense and complex, dominated by eddies flowing southwards and deep currents flowing northwards along the Mozambican margin. Current measurements obtained from moorings at 3400–4050 m water depth in the Zambezi and Tsiribihina valleys show periods of intense currents at the seafloor with peaks of 40–50 cm s−1 that last up to one month and are not related to turbidity currents. These strong bottom-current events are correlated with a change in current direction and an increase in temperature. The periods of current intensification may be related to eddies, since they present similar frequencies (around 7 per year). Moreover, modelling results show that during periods of intense deep circulation an anticyclonic eddy is present between the Mozambican slope and the centre of the Mozambique Channel, which may block the northward transport of the deep water mass and thus enhance the southward transport along the western slope of Madagascar. According to our hydrodynamic modelling of the circulation near the seafloor, intense currents are often present along the Zambezi Valley, especially along the valley flanks. Multi-channel seismic reflection data show that the Zambezi turbidite system does not show the typical characteristics of turbidite systems, being dominated by erosional processes, which mainly affect the valley flanks. Levees associated with the valley are absent in the main axis of the system. The effect of bottom currents on sedimentation in the basin is evidenced by the low sedimentation rates that witness winnowing in the basin, the presence of contouritic sand in the Zambezi Valley flanks and the abundance of current-related bedforms observed in multibeam bathymetry and seismic data. The intense oceanic processes observed in the Mozambique Channel may transport a large part of the fine sediment out of the basin and erode the seafloor even at great depths. Therefore, the Zambezi turbidite system could at present be considered as a mixed turbidite-contourite system, with important implications for source-to-sink studies.
(Marine Geology. vol. 410, n° 0025-3227, pp. 42-55, 28/04/2026)
LGO, UBS, IFREMER, UBO EPE, CNRS, LOPS, IRD, IFREMER, INSU - CNRS, UBO EPE, CNRS, GM, IFREMER, LEP, EEP, IFREMER, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, [Total Fina ELF]
Investigation of the spatial variability of poly- and perfluoroalkyl substance trophic magnification in selected riverine ecosystems
The occurrence at different trophic levels of 17 poly- and perfluoroalkyl substances (PFASs), including perfluoroalkyl acids (PFAAs) and some of their precursors (e.g., perfluoroalkane sulfonamides, 6:2 fluorotelomer sulfonate), were investigated in riverine freshwater food webs in Southeastern France. Two fish species (Barbus barbus and Squalius cephalus) and various invertebrate taxa were collected at five locations to assess the spatial variability of trophic magnification factors (TMFs). Particular attention was devoted to sample and data processing to minimize potential biases associated with the TMF determination. Fish were significantly more contaminated than invertebrates (ΣPFAS = 7-1811 vs. 0.9-213 ng g-1 wet weight (ww)). Those from the Rhône River presented significantly higher levels due to high concentrations of perfluoroundecanoic acid (406 ng g-1 ww) and perfluorotridecanoic acid (566 ng g 1 ww) ascribed to an industrial point source. Perfluorooctane sulfonate (PFOS) was dominant at the other sites (range concentration = 3.6-134 ng g-1 ww). Two linear regression models were compared (i.e., Kendall regression vs. Generalized Linear Mixed-Effect Model, GLMM). Results showed that TMFs calculated using the non-weighted Kendall regression were higher than those obtained using the GLMM approach. GLMM-based TMFs were consistently > 1 for C9-C14 perfluorocarboxylic acids (PFCAs), PFOS and perfluorodecane sulfonate (PFDS), indicating their apparent biomagnification in the investigated food webs. Comparatively, 6:2 FTSA and N-ethylperfluorooctane sulfonamidoacetic acid (N EtFOSAA) were less often detected and were not significantly biomagnified, probably because of metabolization. TMF estimates were generally consistent across sites although some PFASs (in particular C9, C10 and C13 PFCAs) displayed higher variability, due to a unique extreme value that may have resulted from the contribution of unattributed precursor biotransformation.
(Science of the Total Environment, n° 0048-9697, pp. 393-401, 28/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, IRSTEA, EAWAG
A new species of Pista Malmgren, 1866 (Polychaeta, Terebellidae) from the north-western Mediterranean Sea
A new species of Terebellidae, Pista colini sp. n., has been identified from the harbour of Banyuls-sur-Mer, northwestern Mediterranean Sea. This new species was found in very high densities, exclusively in grav-elly sand deposited manually, and was not found in the original source habitat of the gravel. This species is characterized by the colour of the ventral shields with pinkish anterior part and a blood red posterior part in live specimens, a pair of unequal-sized plumose branchiae inserted on segment II and anterior thoracic neuropodia with long-handled uncini. The presence of long-handled uncini even in the smallest specimens constitutes the major difference between Pista colini sp. n. and other Pista species with a single pair of branchiae such as P. lornensis and P. bansei.
(Zookeys. vol. 838, n° 1313-2989, pp. 71-84, 28/04/2026)
OOB, SU, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, IFREMER, SAM
Attribution of ocean temperature change to anthropogenic and natural forcings using the temporal, vertical and geographical structure
We examine whether significant changes in ocean temperatures can be detected in recent decades and if so whether they can be attributed to anthropogenic or natural factors. We compare ocean temperature changes for 1960-2005 in four observational datasets and in historical simulations by atmosphere-ocean general circulation models (AOGCMs) from the Coupled Model Intercomparison Project phase 5 (CMIP5). Observations and CMIP5 models show that the upper 2000 m has warmed with a signal that has a well-defined geographical pattern that gradually propagates to deeper layers over time. Greenhouse gas forcing has contributed most to increasing the temperature of the ocean, a warming which has been offset by other anthropogenic forcing (mainly aerosols), and volcanic eruptions which cause episodic cooling. By characterizing the ocean temperature change response to these forcings we construct multi-model mean fingerprints of time-depth changes in temperature and carry out two detection and attribution analysis. We consider first a two-signal separation into anthropogenic and natural forcings. Then, for the first time, we consider a three signal separation into greenhouse gas, anthropogenic aerosols and natural forcings. We show that all three signals are simultaneously detectable. Using multiple depth levels decreases the uncertainty of the results. Limiting the observations and model fields to locations where there are observations increases the detectability of the signal.
(Climate Dynamics. vol. 53, n° 0930-7575, pp. 5389 - 5413, 28/04/2026)
UOR, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Dispersive and dispersive-like bores in channels with sloping banks
In this paper, a detailed analysis of undular bore dynamics in channels of variable cross-section is presented. Two undular bore regimes, Low Froude Number (LFN) and High Froude Number (HFN), are simulated with a Serre-Green-Naghdi model, and the results are compared with the experiments by Treske. We show that contrary to Favre waves and HFN bores, which are controlled by dispersive non-hydrostatic mechanisms, LFN bores correspond to a hydrostatic phenomenon. The dispersive-like properties of the LFN bores is related to wave refraction on the banks in a way similar to that of edge waves in the nearshore. A fully hydrostatic asymptotic model for these dispersive-like bores is derived and compared to the observations, confirming our claim
(Journal of Fluid Mechanics. vol. 870, n° 0022-1120, pp. 595-616, 28/04/2026)
UGA [2016-2019], IRSTEA, UR ETGR (ETNA), IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, CARDAMOM, IMB, UB, Bordeaux INP, CNRS, Inria