Ammonium and sulfate assimilation is widespread in benthic foraminifera
(Frontiers in Marine Science, n° 2296-7745, 13/04/2026)
LPG, UM, UA, INSU - CNRS, CNRS, Nantes univ - UFR ST, Nantes Univ, EPFL, ENTROPIE [Réunion], IRD, UR, CNRS, WHOI, CAGE, UiT, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UNIL
Impacts des produits phytopharmaceutiques sur la biodiversité et les services écosystémiques. Synthèse de l’expertise scientifique collective
Impacts des produits phytopharmaceutiques sur la biodiversité et les services écosystémiques Synthèse de l'expertise scientifique collective-Mai 2022 Direction de l'expertise scientifique collective, de la prospective et des études (DEPE)
(pp. 136 p., 13/04/2026)
DEPE, INRAE, ECOSYS, INRAE, RiverLy, INRAE, IFREMER, AQUA, INRAE, ISA, UNS, CNRS, INRAE, UniCA, LMGE, CNRS, UCA, UMR BAGAP, ESA, INRAE, Institut Agro, LPED, IRD, AMU, SEBIO, INERIS, URCA, ULH, NU, URCA, CNRS, INERIS, EMMAH, AU, INRAE, MET, ENVL, INRAE, CRIOBE, UPVD, EPHE, PSL, CNRS, CNELIAS, ENS de Lyon, EHESS, AU, AMU, CNRS, LBBE, UCBL, VAS, CNRS, UB, UBFC, INRAE, Institut Agro, LCE, CNRS, UFC, UBFC, UMR SAVE, UB, Bordeaux Sciences Agro, INRAE, DECOD, IFREMER, INRAE, Institut Agro, Institut Agro, OFB, GREDEG, UNS, CNRS, UniCA, LEREPS, UT Capitole, Comue de Toulouse, UT2J, Comue de Toulouse, ENSFEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UMR Eco&Sols, Cirad, IRD, INRAE, Institut Agro, IODE, UR, CNRS, UPR HORTSYS, Cirad, Cirad-PERSYST, Cirad, UMR MARBEC, IRD, IFREMER, CNRS, UM, DipSO, INRAE, AMURE, IRD, IFREMER, UBO EPE, CNRS, UR EABX, INRAE, IMBE, AU, AMU, CNRS, ICRA, UdG, BRM, IFREMER, URAFPA, UL, INRAE, UR HYCAR, INRAE
Freshwater influx to the Eastern Mediterranean Sea from the melting of the Fennoscandian ice sheet during the last deglaciation
Between the Last Glacial Maximum and the mid-Holocene, the Mediterranean Sea experienced major hydrological changes. The deposition of the last sapropel, S1, during the Early Holocene is a consequence of these changes. In order to cause anoxia in the Eastern Mediterranean Sea (EMS) bottom water, a long preconditioning period of a few thousand years would need to occur throughout the deglaciation prior to S1. It is generally believed that this freshwater was of North Atlantic origin, later supplemented by the African Humid period (AHP). Here, we investigate another potentially important source of freshwater to the EMS: the Fennoscandian ice sheet (FIS) meltwater, running into the Caspian and Black Seas. A few scenarios of continental hydrologic perturbation have been developed to drive a high-resolution Mediterranean Sea general circulation model. We demonstrate that, during the last deglaciation, FIS meltwater flowing into the Black Sea reduced surface salinity and ventilation over the main convection areas in the EMS. By including continental hydrological changes, a more consistent framework is produced to characterize the hydrology of the Mediterranean Sea during the last deglaciation and the Early Holocene.
(Scientific Reports. vol. 12, n° 2045-2322, pp. 8466, 13/04/2026)
LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LMD, INSU - CNRS, X, IP Paris, ENPC, SU, CNRS, ENS-PSL, PSL, GEOPS, INSU - CNRS, CNRS, GEOAZUR 7329, INSU - CNRS, UniCA, CNRS, IRD [Occitanie], UniCA, UTokyo
Modelling the contribution of wind waves to Cap Ferret's updrift erosion
Wind waves breaking at an angle with the shoreline force the drifting of littoral sediments, which is known for contributing to the formation and growth of barrier spits. Intriguingly, increased rates of longshore wave power have also been associated with the erosion of some barrier spits on the updrift margin of tidal inlets. Therefore, a numerical experiment was designed and is presented here, which investigates the possible links between the longshore wave power and the shortening of these elongated coastal barriers. Based on a process-based model, the experiment provides new insights into the forces at play in the redistribution of sediments between a sandspit and its adjacent inlet, respectively the Cap Ferret and the Bay of Arcachon's tidal inlet, in SW France. More particularly, model scenarios were defined that show how combined waves and tide create gradients of residual sediment transport responsible for a sediment deficit at the spit – inlet boundary. The deficit was also found to deepen with increasing longshore wave energy, as if the transfer of sediment from the spit to inlet shoals was accelerated. This physically explains the previously observed retreat of the spit's distal end during periods dominated by the positive phase of North Atlantic Oscillation (NAO) in winter. Indeed, according to model results, higher and/or more oblique waves associated with the positive phase of the NAO are expected to increase the transfer and storage of the drifting sediments to and by the inlet shoals, and this at the expense of the spit. While these conclusions remain valid, we noticed that the sensitivity of model results to the bottom friction enhanced the importance of accurately representing the spatio-temporal distribution of bed roughness when investigating the morphodynamic interactions between real-world tidal inlets and their margins.
(Coastal Engineering. vol. 172, n° 0378-3839, pp. 104063, 13/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, BRGM, LIENSs, INSU - CNRS, ULR, CNRS
Biomass partitioning of plants under soil pollution stress
Polluted sites are ubiquitous worldwide but how plant partition their biomass between different organs in this context is unclear. Here, we identified three possible drivers of biomass partitioning in our controlled study along pollution gradients: plant size reduction (pollution effect) combined with allometric scaling between organs; early deficit in root surfaces (pollution effect) inducing a decreased water uptake; increased biomass allocation to roots to compensate for lower soil resource acquisition consistent with the optimal partitioning theory (plant response). A complementary meta-analysis showed variation in biomass partitioning across published studies, with grass and woody species having distinct modifications of their root: shoot ratio. However, the modelling of biomass partitioning drivers showed that single harvest experiments performed in previous studies prevent identifying the main drivers at stake. The proposed distinction between pollution effects and plant response will help to improve our knowledge of plant allocation strategies in the context of pollution.
(Communications Biology. vol. 5, n° 2399-3642, 13/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, EVS, ENS de Lyon, Mines Saint-Étienne MSE, IMT, UL2, UJML, INSA Lyon, INSA, UJM, ENTPE, ENSAL, CNRS, ALLHiS, UJM, BioGeCo, UB, INRAE
Three new deep-sea species of Marphysa (Annelida, Eunicida, Eunicidae) from Papua New Guinea (Bismarck and Solomon seas)
Three new species of Marphysa Quatrefages, 1866, Marphysa banana sp. nov., Marphysa papuaensis sp. nov., and Marphysa zanolae sp. nov. are described from deep-sea sunken vegetation off Papua New Guinea, using both morphology and molecular data (for two species). With the presence of compound spinigers only and the branchiae present over many chaetigers, Marphysa banana sp. nov. belongs to the group B2. This species is characterised by the presence of eyes, the presence of branchiae starting from chaetiger 20, and by the presence of three types of pectinate chaetae and bidentate subacicular hooks starting from chaetigers 13-52. With the presence of compound falcigers only and the branchiae restricted to a short anterior region, Marphysa papuaensis sp. nov. belongs to the group C1. This species has a bilobed prostomium but no eyes, has branchiae from chaetigers 7 to 14-16 with up to 16 filaments. Marphysa papuaensis sp. nov. is also characterised by the presence of bidentate subacicular hooks from chaetiger 20 and by a single type of pectinate chaetae. Finally, Marphysa zanolae sp. nov. belongs to the group C2, with the presence of compound falcigers only and the branchiae present over many chaetigers. This species is characterised by the absence of eyes, by the presence of branchiae with a single long filament starting from chaetiger 31, by unidentate subacicular hooks starting from chaetiger 28 and finally by one type of pectinate chaetae with very long outer teeth.
(Zookeys. vol. 1122, n° 1313-2989, pp. 81-105, 13/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UMS POREA, INSU - CNRS, CNRS, INRAE, AMRI, LECOB, SU, CNRS, OOB, SU, CNRS
Screening of the Toxicity of Polystyrene Nano-and Microplastics Alone and in Combination with Benzo(a)pyrene in Brine Shrimp Larvae and Zebrafish Embryos
The occurrence of nanoplastics (NPs) and microplastics (MPs) in aquatic ecosystems and their capacity to sorb hydrophobic pollutants is nowadays an issue of great concern. This study aimed to assess the potential bioavailability and acute toxicity of polystyrene (PS) NPs (50 and 500 nm) and of MPs (4.5 µm), alone and with sorbed benzo(a)pyrene (B(a)P), in the embryo/larval stages of brine shrimps and zebrafish. Exposure to pristine plastics up to 50.1 mg PS/L did not cause significant impact on brine shrimp survival, while some treatments of plastics-B(a)P and all concentrations of B(a)P (0.1–10 mg/L) resulted acutely toxic. In zebrafish, only the highest concentrations of MPs-B(a)P and B(a)P caused a significant increase of malformation prevalence. Ingestion of NPs was observed by 24–48 h of exposure in the two organisms (from 0.069 to 6.87 mg PS/L). In brine shrimps, NPs were observed over the body surface and within the digestive tract, associated with feces. In zebrafish, NPs were localized in the eyes, yolk sac, and tail at 72 h, showing their capacity to translocate and spread into the embryo. MP ingestion was only demonstrated for brine shrimps. In zebrafish embryos exposed to plastics-B(a)P, B(a)P appeared in the yolk sac of the embryos. The presence of B(a)P was also noticeable in brine shrimps exposed to 500 nm NPs-B(a)P. In conclusion, NPs entered and spread into the zebrafish embryo and PS NPs, and MPs were successful vectors of B(a)P to brine shrimp and zebrafish embryos. Particle size played a significant role in explaining the toxicity of plastics–B(a)P. Our study provides support for the idea that plastics may pose a risk to aquatic organisms when combined with persistent organic pollutants such as B(a)P.
(Nanomaterials. vol. 12, n° 2079-4991, pp. 941, 13/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UPV / EHU
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
Particle tracking as a vulnerability assessment tool for drinking water production
The simulation of concentration values and use of such data for historymatching is often impeded by the computation time of groundwater transport models based on the resolution of the advection-dispersion equation. This is unfortunate because such data are often rich in information and the prediction of concentration values is of great interest for decision making. Particle tracking can be used as an efficient alternative under a series of simplifying assumptions, which are often reasonable at groundwater sinks (wells and drains). Our approach consists of seeding particles around a sink and tracking particles backward, up to the source boundary condition, such as a contaminated stream. This particle tracking approach allows the use of parameter estimation and optimization methods requiring numerous model calls. We present a Python module facilitating the pre-and post-processing operations of a modeling workflow based on the widely used USGS MODFLOW6 and MODPATH7 programs. The module handles particle seeding around the sink and estimation of the mixing ratio of water withdrawn from the sink. This ratio is computed with a mixing law from the particle endpoints, accounting for particle velocities and mixing in the source model cells. We investigate the best practice to obtain robust derivatives with this approach, which is a benefit for the screening methods based on linear analysis. We illustrate the interest of the approach with a real world case study, considering a drinking water well field vulnerable to a contaminated stream. The configuration is typical of many other drinking water production sites. The modeling workflow is fully script-based to make the approach easily reproducible in similar cases.
(Frontiers in Earth Science, n° 2296-6463, 13/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, HSM, IRD, INSU - CNRS, CNRS, UM, INSU - CNRS, CNRS, UA, UM
Higher facilitation for stress‐intolerant ecotypes along a metal pollution gradient are due to a decrease in performance in absence of neighbours
The study of variation in plant-plant interactions along metal-pollution gradient is in its infancy, although this is worth to be assessed for both restoration and theoretical perspectives. Additionally, the mechanisms of facilitation at stake in these particular stressed conditions are poorly known. We aim at understanding the importance of species and ecotypes stress-tolerance in competitive and facilitative responses to neighbours along metal-pollution gradients. We addressed this goal in a field experiment conducted in a former mining area located in a subalpine grassland of the French pyrenees. Two ecotypes of Armeria muelleri (a highly tolerant species to metal stress) and Agrostis capillaris (a less stress-tolerant species) were harvested at the highest and lowest levels of pollution within their distribution range and transplanted with and without neighbours along a strong metal-pollution gradient. The relative interaction index (RII) was used to assess both the effect of neighbours at different stress levels and the effect of metallic stress with and without neighbours. With increasing pollution, plant-plant interactions shifted from negative to positive for Agrostis, but did not vary significantly for Armeria. At high pollution level, the unpolluted Agrostis ecotype was more facilitated than the polluted one, and in benign habitats the polluted Armeria ecotype was more sensitive to competition than the less polluted ecotype. Interestingly, the increase in facilitation with increasing metal stress for the stress-intolerant Agrostis ecotype was primarily due to a decrease in performance without neighbours, whereas the increase in competition with decreasing metal stress for the stress-tolerant Agrostis ecotype was primarily due to an increase in performance with neighbours. More generally, these results suggest that the high size-plasticity of competitive (and stress-intolerant) species or ecotypes may explain both their competitive effects in benign habitats through neighbour-trait effects and facilitative responses in stressed habitats in the context of environmental-severity effects.
(Oikos, n° 0030-1299, 13/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UMR ISPA, Bordeaux Sciences Agro, INRAE