Utilisation des échantillonneurs passifs pour évaluer la contamination des écosystèmes aquatiques par les produits phytosanitaires - Application à un bassin versant viticole
L'échantillonnage passif représente une alternative aux prélèvements ponctuels pour la détermination de la contamination en pesticides. Les échantillonneurs présentent l'avantage d'intégrer la contamination du milieu pendant la période d'exposition de l'outil et permettent un abaissement des limites de détection grâce à l'accumulation des substances. Parmi les outils existants, les échantillonneurs passifs intégratifs pour les contaminants organiques polaires (POCIS : Polar Organic Chemical Integrative Samplers) ont été utilisés avec succès pour évaluer la contamination des hydrosystèmes en contexte agricole [1]. Ces POCIS peuvent être adaptés pour permettre la surveillance de milieux exigus ou de milieux à écoulements épisodiques tels que les fossés agricoles. Ces adaptations consistent à modifier les dimensions de l'outil, la surface membranaire, la quantité de phase ou encore la porosité des membranes pour influencer la quantité de substances accumulées [2]. Le projet de recherche multidisciplinaire PhytoCOTE étudie l'usage des pesticides dans les agrosystèmes, leurs transferts dans les écosystèmes connexes, leur bioaccumulation, et leur toxicité potentielle chez les organismes aquatiques. Le site d'étude est localisé dans une zone d'exploitation viticole sur la rive droite de l'estuaire de la Gironde. Dans ce cadre, un suivi annuel de la variabilité spatio-temporelle des concentrations en pesticides a été mis en place. Le suivi des cours d'eau permanents (ordre 1, 2 et 3) repose sur le déploiement de POCIS classiques à une fréquence mensuelle. Le suivi des fossés repose sur le déploiement de POCIS adaptés (miniPOCIS et POCIS-T) pendant la période d'application des pesticides. Parallèlement, des prélèvements d'eau sont réalisés à une fréquence mensuelle ou bimensuelle. Le suivi de la contamination est basé sur une liste de plus de 200 substances parmi lesquels les pesticides utilisés sur le bassin versant (54 substances). Différentes techniques d'extraction et d'analyse par LC-MS/MS et GC-MS/MS ont été développées pour permettre la quantification de ces composés.
(pp. 2, 21/06/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UR ETBX, IRSTEA
How does climate change make fish late for dinner?
Imagine you are a young and hungry fish looking for food in an estuary (the part of a river where it meets the ocean). You need to grow big and strong before you migrate to the ocean, and depend on tiny floating creatures (plankton) for food. However, the occurrence of these tiny creatures in the estuary varies seasonally. Lucky for you, nature has synchronized both your time in the estuary and that of your prey, and you survive. This synchronization depends on many different factors, among them the temperature of the water. Now imagine someone turning up the heat (like we humans are doing by changing the climate). Could the rising water temperatures mess up the timing for you, the predator, and your prey? To answer this question we looked at climate related changes in the synchronization of predator and prey in the biggest estuary in Western Europe. And indeed, we found signs of temporal mismatches in its aquatic food web. We fear that the observed changes can put this important ecosystem and its role as a big fish nursery at risk.
(Environmental Science Journal for Teens, pp. 5, 21/06/2026)
UR EABX, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Main Ecological Features of Benthic Macrofauna in Mediterranean and Atlantic Intertidal Eelgrass Beds: A Comparative Study
The present study compares the intertidal eelgrass macrofauna in two geographically and ecologically disparate localities (central Mediterranean and eastern Atlantic). Both coastal ecosystems are developed on extensive large mudflats with eelgrass beds, hosting a great diversity of water birds and providing important socioeconomic assets. These two distinct and distant geographical ecosystems are affected by numerous anthropogenic pressures. By reflecting the response of the structure and functioning of benthic communities to climate change, the two eelgrass ecosystems provide a natural laboratory to investigate global warming. The macrobenthic fauna community of Zostera (Zosterella) noltei eelgrass beds was studied by sampling 34 stations in the Kneiss Islands and 48 stations in Arcachon Bay. A total of 148 species are identified in the Kneiss islands and 117 species in Arcachon Bay, but only 23 species are common to both ecosystems. Diversity, abundance and community structure are significantly different between the two study areas, which could be explained by differences between Mediterranean and Atlantic climatic conditions and by anthropic factors (e.g. fishing pressure, pollution, nutrient inputs) affecting each ecosystem. Multidimensional scaling (n-MDS) analysis identifies two distinct geographical station groups on the basis of species and family-level abundance. On the contrary, three assemblages are identified on the basis of trophic groups distributed between the separate ecosystems. In terms of ecological quality status, the Kneiss site appears to have a good ecological condition and hosts a variety of sensitive species. On the other hand, biotic indices indicate that the Arcachon site is moderately perturbed and that the benthic communities are unbalanced. It is expected that the present-day functioning of the Kneiss Islands ecosystem will become typical of the situation in Arcachon Bay in several decades time, with the development of warmer and drier conditions.
(Journal of Marine Biology & Oceanography. vol. 6, pp. 100174, 21/06/2026)
FSS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, M2C, UNICAEN, NU, INSU - CNRS, UNIROUEN, NU, CNRS
Shoreline resilience to individual storms and storm clusters on a meso-macrotidal barred beach
This study investigates the impact of individual storms and storm clusters on shoreline recovery for the meso-to macrotidal, barred Biscarrosse beach in SW France, using 6 years of daily video observations. While the study area experienced 60 storms during the 6-year study period, only 36 storms were analysed due to gaps in the video data. Based on the 36 individual storms and 13 storm clusters analysed, our results show that clustering impact is cumulatively weak and shoreline retreat is governed by the first storms in clusters, while the impact of subsequent events is less pronounced. The average post-storm beach recovery period at this site is 9 days, consistent with observations at other beaches. Apart from the dominant effect of present storm conditions, shoreline dynamics are also significantly affected by previous storm influence, while recovery is strongly modulated by tidal range and the bar location. Our results reveal that not only is the storm energy important but also the frequency of recurrence (storms result in greater retreat when time intervals between them are longer), which suggests an interaction between short storm events and longer-term evolution.
(Geomorphology. vol. 290, n° 0169-555X, pp. 265-276, 21/06/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LEGOS, IRD, UT3, Comue de Toulouse, INSU - CNRS, CNES, CNRS
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, 21/06/2026)
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
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, 21/06/2026)
ISYEB, MNHN, UPMC, EPHE, PSL, CNRS, 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, 21/06/2026)
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
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, 21/06/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UF, UTC, Cerema
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, 21/06/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
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, 21/06/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UR EABX, IRSTEA