Combined effects of temperature and copper and S-metolachlor on embryo-larval development of the Pacific oyster, Crassostrea gigas
This study evaluates the combined effects of two contaminants (copper and a herbicide S-metolachlor) and temperature on the early life stages of the Pacific oyster Crasssotrea gigas,which is native to Arcachon Bay (southwest France). The responses of D-larvae, obtained fromwild and cultivated oysters,were investigated for one year during the oyster breeding period at different sampling sites and compared with the response of D-larvae from a commercial hatchery. Embryotoxicity was measured by considering the percentage of abnormal D-shaped larvae. Normal development of embryos occurred only from 22 °C to 26 °C. There were synergistic effects of copper at low and high temperatures. Native oysters appear particularly sensitive to an increase in water temperature, suggesting a future increase in the percentage of larval abnormalities as a result of global climate change. Hatchery oysters represent a good alternative model for studying the effects of both pollutants and climate change stressors.
(Marine Pollution Bulletin. vol. 115, n° 0025-326X, pp. 201-210, 27/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UR EABX, IRSTEA
Lateral variability of subtidal flow at the mid-reaches of a macrotidal estuary
Transverse variations of tidal and subtidal flow were investigated in a macrotidal and convergent estuary. This was accomplished by combining data analysis of current velocities and water density with numerical modeling at the mid-reaches of the Gironde Estuary (France). Nonlinear mechanisms responsible for overtide generation and hence subtidal flows were found to vary across the estuary and from neap to spring tides. Subtidal flows were driven by a combination of internal asymmetry, tidal advective accelerations, nonlinear effects of water level variations, quadratic friction, and river discharge. The quarter-diurnal overtide band (D4) in the flow was generated by internal asymmetry and tidal advective accelerations during neap tide. The ratio of quarter-diurnal to squared semidiurnal bands (D4/D22) was largest (>0.3) in sections of the channel showing subtidal outflow. River discharge increased from neap to spring tides causing a subsequent increase of seaward subtidal currents. During spring tide, D4 was generated by tidal advective accelerations and quadratic friction combined with river discharge, rather than by internal asymmetry. The sixth-diurnal overtide (D6) in the flow was comparable to D4 for both neap and spring tides. Largest D6/D23 ratios were found in the shallowest cross-channel locations during both neap and spring tides.
(Journal of Geophysical Research. Oceans. vol. 122, n° 2169-9275, pp. 7651-7673, 27/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UF, UTC, Cerema
Spatial and temporal distribution of mercury and methylmercury in bivalves from the French coastline
Marine mercury (Hg) concentrations have been monitored in the French coastline for the last half a century using bivalves. The analyses presented in this study concerned 192 samples of bivalves (mussels: Mytilus edulis and Mytilus galloprovincialis and oysters: Crassostrea gigas and Isognomon alatus) from 77 sampling stations along the French coast and in the French Antilles sea. The goals of this study were to assess MeHg levels in various common bivalves from French coastline, and to identify possible geographic, taxonomic or temporal variations of concentrations. We show that the evolution of methylmercury (MeHg) concentrations covary with total mercury (HgT) concentrations. Moreover, in most of the study sites, HgT concentrations have not decreased since 1987, despite regulations to decrease or ban mercury used for anthropic activities.
(Marine Pollution Bulletin. vol. 114, n° 0025-326X, pp. 1096-1102, 27/04/2026)
BE, IFREMER, LERPAC, COAST, IFREMER, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, GET, IRD, UT3, Comue de Toulouse, INSU - CNRS, CNES, CNRS
New records of benthic amphipods, Jassa slatteryi Conlan, 1990 and Ampithoe valida Smith, 1873 (Crustacea: Peracarida: Amphipoda) for the Bay of Biscay, France, with morphological notes
Jassa slatteryi and Ampithoe valida were collected in the Bay of Biscay. Jassa slatteryi, a cosmopolitan species, was signalized before in European waters, in the Mediterranean Sea and in Brittany. Specimens collected in Arcachon Bay represent the second signalization on the European Atlantic coast. Ampithoe valida, a non-native species originally described in North America, was signalised in European waters before, in the Mediterranean Sea, Portugal and the Netherlands. Its presence in Arcachon Bay and Hossegor Lake is a first record on the French Atlantic coast for this species.
(Cahiers de Biologie Marine, n° 0007-9723, 27/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
How Much CO 2 Is Taken Up by the European Terrestrial Biosphere?
(Bulletin of the American Meteorological Society. vol. 98, n° 0003-0007, pp. 665 - 671, 27/04/2026)
UCL, IUP, SRON, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, SATINV, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, ICOS-ATC, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA
Regional seesaw between the North Atlantic and Nordic Seas during the last glacial abrupt climate events
Dansgaard–Oeschger oscillations constitute one of the most enigmatic features of the last glacial cycle. Their cold atmospheric phases have been commonly associated with cold sea-surface temperatures and expansion of sea ice in the North Atlantic and adjacent seas. Here, based on dinocyst analyses from the 48–30 ka interval of four sediment cores from the northern Northeast Atlantic and southern Norwegian Sea, we provide direct and quantitative evidence of a regional paradoxical seesaw pattern: cold Greenland and North Atlantic phases coincide with warmer sea-surface conditions and shorter seasonal sea-ice cover durations in the Norwegian Sea as compared to warm phases. Combined with additional palaeorecords and multi-model hosing simulations , our results suggest that during cold Greenland phases, reduced Atlantic meridional overturning circulation and cold North Atlantic sea-surface conditions were accompanied by the subsurface propagation of warm Atlantic waters that re-emerged in the Nordic Seas and provided moisture towards Greenland summit.
(Climate of the Past. vol. 13, n° 1814-9324, pp. 729-739, 27/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, GLACCIOS, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, AWI, CLIMAG, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA
Grotte de Bruniquel (Tarn-et-Garonne, France) : éléments de datation complémentaires
La grotte de Bruniquel renferme six structures architecturées dont une grande et une plus petite plus ou moins circulaires et quatre accumulations, composées au total de 420 stalagmites entières ou fragmentées, localisées à environ 300 mètres de l’entrée. Leur construction a été datée en 2016 de 176 500 ± 2 100 ans (SIM 6) grâce à la datation uranium-thorium des stalagmites. Les Hommes de Néandertal ne seraient apparemment pas entrés par l’accès actuel, l’éboulis d’entrée étant scellé par plusieurs générations de stalagmites dont certaines très massives. Il reste donc une inconnue quant à l’âge de cet éboulis et l’existence d’un éventuel porche d’entrée contemporain de Néandertal. Dans cet article, la grotte est replacée dans son contexte géologique, karstologique et géomorphologique. Les nouvelles dates sur les structures affinent la limite minimale de l’âge des constructions et les premières dates sur l’éboulis montrent quant à elles un âge relativement ancien sans toutefois pouvoir exclure une ouverture d’une partie de l’éboulis à ~170 ka.
(Karstologia. vol. 52, n° 0751-7688, pp. 1187-1210, 27/04/2026)
IRSNB / RBINS, PACEA, UB, CNRS, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Influence of Environmental Factors on the Fate of Legacy and Emerging Per- and Polyfluoroalkyl Substances along the Salinity/Turbidity Gradient of a Macrotidal Estuary
This study aimed at bridging knowledge gaps regarding the land-sea transport of per- and polyfluoroalkyl substances (PFASs) through riverine discharge into coastal waters. The present survey was conducted in the Gironde estuary (southwestern France) where PFASs were ubiquitously detected albeit at low levels. Emerging PFASs such as fluorotelomer sulfonates or polyfluoroalkyl phosphate diesters accounted for a relatively minor proportion of ∑PFASs, while perfluorooctanesulfonate, perfluorohexanesulfonate, and perfluorohexanoate were the predominant congeners. Multiple linear regressions provided insights into the relative influence of factors controlling PFAS sediment levels. In that respect, the organic carbon fraction (strongly correlated to sediment grain size) appeared as a more important controlling factor than black carbon or distance from upstream sources for long-chain perfluoroalkyl acids. In the maximum turbidity zone (suspended solids up to 2600 mg L–1), the particle-associated fraction was almost consistently >50% for long-chain perfluoroalkyl carboxylates and sulfonates (≥C8 and ≥ C6, respectively). Empirical models of KD partitioning coefficients were derived by integrating, for the first time, both particle-concentration and salting-out effects. These results represent significant progress toward the development of numerical transport models integrating both PFAS partitioning and 3D-hydrosedimentary dynamics, with a view to estimate PFAS mass budgets at the land-sea interface.
(Environmental Science and Technology. vol. 51, n° 0013-936X, pp. 12347-12357, 27/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LPTC, UB, CNRS
First observations of the behaviour of the deep-sea amphipod Dulichiopsis dianae sp. nov. (Senticaudata, Dulichiidae) in the TAG hydrothermal vent field (Mid-Atlantic Ridge)
A “tiny and mysterious creature swinging on a stem”: that was the first observation of the new species Dulichiopsis dianae sp. nov. made during the remotely operated vehicle (ROV) dive devoted to the exploration of the surroundings of the vent site TAG (BICOSE cruise, 3550–3650 m). The viewing and analysis of the high-definition pictures from several dives (PL570, PL573 and PL575) corresponding to five different locations around TAG revealed that these organisms were amphipods, hung on erected and flexible masts (5–7 cm length) attached to the underlying hard substratum. Two specimens were opportunely sampled during dive PL575 (3637 m) with the suction sampler of the ROV and were identified as a new species ascribed to the genus Dulichiopsis (family Dulichiidae). The present study provides the morphological description of this new species, coupled with in situ observations of its behaviour and lifestyle in the vicinity of the TAG vent field. Taxonomic and ecological aspects of the family Dulichiidae are proposed here, as well as a review of the amphipod diversity in hydrothermal environments.
(Marine Biodiversity, n° 1867-1616, 27/04/2026)
ISYEB, MNHN, UPMC, EPHE, PSL, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Understanding the impact of silver as an emerging contaminant in the Ibaizabal and Gironde estuaries
Estuaries have been subjected to a high human pressure which has led to the presence of pollutants in their waters and sediments including trace metals. The estuaries in the Bay of Biscay do not constitute an exception of this situation and the Ibaizabal and Gironde Estuaries are both very well known for having high metal concentrations in different compartments. In this context, environmental health monitoring programmes have relied on the use of mussels and oysters as sentinel organisms because chemical and biological analyses of their tissues allow assessing the general health status of their surrounding environment. The present work aims at acquiring a deeper understanding of the interactions between bioaccumulation and the toxic effects of copper (Cu) and silver (Ag) in oysters Crassostrea gigas, as well as the effects that environmental factors may have on them, For this, one field study and three laboratory experiments have been carried out. Among the most relevant results obtained it can be highlighted that: (I) both oysters and mussels are useful to properly indicate the health status of estuaries of the Bay of Biscay, yet higher accumulation of metals occurs in oysters than in mussels, (II) the intake pathway (watercolumn and/or food) induces different response intensities in oysters (III) the toxicity of Ag is enhanced in the presence of Cu in oysters and (IV) salinity has a low effect on the toxicity of both metals in oysters.
(16/12/2016)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS