New insights into eDNA sorption onto environmental carbonaceous materials
A recommendation – based on reviews by Jérôme Duval and one anonymous reviewer – of the article: Jelavic S, Thygesen LG, Magnin V, Findling N, Müller S, Meklesh V, Sand KK (2022) Soot and charcoal as reservoirs of extracellular DNA. ChemRxiv, ver. 5 peer-reviewed and recommended by Peer Community in Ecotoxicology and Environmental Chemistry. https://doi.org/10.26434/chemrxiv-2021-9pz8c-v5
(Peer Community In Ecotoxicology and Environmental Chemistry, n° 2779-9948, pp. 100003, 09/12/2022)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
High sensitivity detection of nanoparticles permeation through polymer membranes: A physico-chemical and nuclear imaging measurement approach
Diffusion cells are devices made of donor and acceptor compartments (DC and AC), separated by a membrane. They are widely used in pharmaceutical, cosmetic, toxicology, and protective equipment tests (e.g., gloves) to measure the kinetics of permeants (molecules and nanoparticles) across biological membranes as the skin. However, rarely is the concentration of permeants in the AC measured in continuous or in real-time, and this limitation leads to significant discrepancies in the calculations of kinetic parameters that define the permeation mechanisms. In this study, a diffusion cell compatible with positron emission tomography was used to measure the permeation kinetics of nanoparticles across glove membranes. The technology allows for the measurement of nanoparticle concentration in real-time in the two compartments (DC and AC) and at a detection sensitivity several orders of magnitude higher compared with conventional spectroscopies, thus allowing a much more precise extraction of kinetic parameters. Ultra-small (<10 nm) gold nanoparticles were used as a model nanoparticle contaminant. They were radiolabeled, and their diffusion kinetics was measured in continuous through latex and nitrile polymer membranes. Permeation profiles were recorded at sub-nanomolar sensitivity and in real-time, thus allowing the high precision extraction of kinetic permeation parameters. The technology, methodology, and data extraction process developed in this work could be applied to measure in real-time the kinetics of diffusion of a whole range of potentially toxic molecules and nanoparticles across polymer membranes, including glove membranes.
(Review of Scientific Instruments. vol. 93, n° 0034-6748, 06/12/2022)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Clarifying the Role of ENSO on Easter Island Precipitation Changes: Potential Environmental Implications for the Last Millennium
El Niño Southern Oscillation (ENSO) events yield precipitation deficits and ensuing droughts, often damaging regional forests, in many parts of the world. The relative roles of ENSO, other natural climate changes, and anthropogenic factors on the forest clearing of Easter Island over the last millennium are still debated. Here, we analyze Easter Island precipitation changes using in situ, satellite-derived and reanalysis products spanning the last 4–7 decades, and 46 monthly 156-year-long (1850–2014) simulations derived from 25 CMIP5 and 21 CMIP6 (Coupled Model Intercomparison Project phases 5 and 6) General Circulation Models. Our analysis shows that La Niña events, the cold phases of ENSO, cause precipitation deficits of −0.2 to −0.3 standard deviation (relative to long-term mean) in all analyzed data types. ENSO-like events are further examined over the last millennium (850–1981). A new multiproxy reconstruction of the NINO3.4 index based on proxy records from the Past Global Changes 2k database and Random Forest method is produced. Our reconstruction reveals unusual high recurrences of La Niña-like situations during the fifteenth to seventeenth centuries, which likely induced significant precipitation deficits on the island. These situations are compared to published vegetation reconstructions based on pollen analyses derived from sedimentary cores collected in three island sites. We conclude the environmental consequences of cumulative precipitation deficits over long-lasting La Niña-like situations reconstructed here over the fifteenth to seventeenth centuries were likely favoring drought and forest flammability. La Niña events should be better accounted for among the causes of forest clearing on Easter Island.
(Paleoceanography and Paleoclimatology. vol. 37, n° 2572-4525, 05/12/2022)
LEGOS, IRD, UT3, Comue de Toulouse, INSU - CNRS, CNES, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UdeC, HNHP, MNHN, UPVD, CNRS
The Rance tidal power station: Toward a better understanding of sediment dynamics in response to power generation
A three-dimensional coupled hydrodynamic and morphodynamic numerical model was developed to analyze sediment dynamics in the Rance estuary, in response to the tidal power station (TPS) built near the mouth in the 1960s. The Rance estuary is a relatively small low-discharge steep-sided ria, located along the Brittany coast in northern France, with a maximum spring tidal range of 13.5m. Taking advantage of this significant tidal regime, the first and currently the second largest operational tidal power station in the world was built at the estuary’s mouth, with peak output capacity of 240MW. After calibration and validation of the model for present-day conditions, suspended sediment concentration (SSC) and bed level evolution were evaluated at tidal and fortnightly scales for different scenarios, with and without TPS. Peak SSC are reached during spring tides and specifically during the estuary’s infilling (flood) stage where both turbines and sluice gates are open. Unbalanced with sediment transport during ebb, sediments are accumulated in the main channel of the upper estuary. Under natural tidal forcing (i.e., without TPS), simulations show that an estuarine turbidity maximum forms in the upper estuary, and sediment deposition is significant. However, sedimentation rates are two times lower than those observed in the presence of the TPS. A possible alternative for reducing sediment accumulation in the upper estuary would be the opening of sluice gates simultaneously with the turbines during falling tide, to enhance ebb currents that would allow particles transport towards the estuary’s downstream.
(Renewable Energy. vol. 201, n° 0960-1481, pp. 323-343, 01/12/2022)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Coastal plumes contribution to the suspended sediment transport in the Southwest Atlantic inner continental shelf
Global coastal zones are constantly changing due to the actions of various physical forces. Recent studies show that the supply of suspended sediment of continental origin plays an important role in these changes. Once in the coastal region, this sediment significantly influences the sedimentation process on the inner shelf. Thus, understanding the transport and destination of these suspended sediments is crucial to interpret the morphodynamic evolution of the seabed and biogeochemical processes in the ocean. The Southwest Atlantic Shelf is the largest continental shelf in the Southern Hemisphere and one of the most important in biological production, because of the great continental contribution exercised by both Río de la Plata and Patos Lagoon. Studies in the region showed that these effluents are significantly affected by the El Niño–Southern Oscillation (ENSO) effect, which can interfere with the availability of suspended material inserted into the coastal region. Despite the great efforts of several authors to understand these changes and their interactions with the environment, some questions remain unanswered. Thus, this work aims to fill this gap by answering questions related to the contribution of suspended sediment of continental origin and its behaviour on the Southwest Atlantic Inner Shelf. The behaviour of suspended sediment was investigated in two distinct periods using the hydro-morphodynamic model TELEMAC-3D: one representing normal years, that is, without the effect of ENSO (2005–2006) and the other experiencing the effect of ENSO (2008–2009).The model was calibrated and validated using field data for both studied periods. R esults were based on statistical analysis, such as wavelet and empirical orthogonal function (EOF) analysis, in addition to time series analysis. Results showed that the Southwest Atlantic Inner Shelf is mainly influenced by the fluvial discharge of Río de la Plata and Patos Lagoon, and by the local wind. Río de la Plata is the largest exporter of suspended sediment in the region, with an approximate rate of 1.2 × 108 tons.year-1 in neutral (normal) years and 3.0 × 108 tons.year-1 in years under the influence of ENSO. The Patos Lagoon, on the other hand, exports approximately 1.25 × 107 tons.year-1 in the period without the ENSO effect and 1.35 × 107 tons.year-1 in the period influenced by ENSO. Results also showed that the fluvial discharge interacts with the suspended sediment in seasonal to interannual scales, while the wind contributes to the concentration of suspended sediment on synoptic scales. Still on the wind regime, results show that the local wind regime gains importance particularly when the suspended sediment reaches the coastal region.
(Journal of Marine Systems. vol. 236, n° 0924-7963, 01/12/2022)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Inferring volumetric changes at a shallow lake from subpixel satellite-derived shorelines
(Applied Geography. vol. 149, n° 0143-6228, 01/12/2022)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Fiches descriptives des habitats marins benthiques de la Manche, de la Mer du Nord et de l’Atlantique
Ce catalogue présente l’ensemble des fiches descriptives des 108 unités de niveau 2 de la troisième version de la typologie NatHab-Atl (habitats marins benthiques de la Manche, de la Mer du Nord et de l’Atlantique), pour servir d’outil d’aide à l’identification et la conservation des habitats. Les habitats ont été décrits sur la base des descriptions existantes dans d’autres typologies complétées par les connaissances disponibles. Ce travail a permis de mettre à jour la typologie en modifiant le libellé de 10 unités pour clarifier leur contenu ou suivre les évolutions taxonomiques de leurs espèces caractéristiques, en supprimant une unité de niveau 3 et déplaçant les unités de niveau 4 qu’elle contenait. Ce travail a également permis d’identifier que le statut de présence en France de 22 unités était à confirmer. Toutes les fiches descriptives ainsi que des photos illustratives supplémentaires sont disponibles en ligne sur les pages habitats de l’INPN.
(pp. 578 pages, 01/12/2022)
PatriNat, MNHN, CNRS, OFB, LEFE, INEE-CNRS, CNRS, UT3, Comue de Toulouse, CNRS, Toulouse INP, Comue de Toulouse, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, DGD.REVE, MNHN, LEMAR, IRD, IFREMER, UBO EPE, CNRS, FR2424, SBR, SU, CNRS, SBR, SU, CNRS, IFREMER, IUEM, IRD, INSU - CNRS, UBO EPE, CNRS
Early warning signal for a tipping point suggested by a millennial Atlantic Multidecadal Variability reconstruction
Abstract Atlantic multidecadal variability is a coherent mode of natural climate variability occurring in the North Atlantic Ocean, with strong impacts on human societies and ecosystems worldwide. However, its periodicity and drivers are widely debated due to the short temporal extent of instrumental observations and competing effects of both internal and external climate factors acting on North Atlantic surface temperature variability. Here, we use a paleoclimate database and an advanced statistical framework to generate, evaluate, and compare 312 reconstructions of the Atlantic multidecadal variability over the past millennium, based on different indices and regression methods. From this process, the best reconstruction is obtained with the random forest method, and its robustness is checked using climate model outputs and independent oceanic paleoclimate data. This reconstruction shows that memory in variations of Atlantic multidecadal variability have strongly increased recently—a potential early warning signal for the approach of a North Atlantic tipping point.
(Nature Communications. vol. 13, n° 2041-1723, pp. 5176, 01/12/2022)
IMAU, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, BSC-CNS, LOCEAN-VARCLIM, LOCEAN, MNHN, IRD, INSU - CNRS, SU, CNRS, IPSL (FR_636), ENS-PSL, UVSQ, CEA, INSU - CNRS, X, CNES, SU, CNRS, UPCité, Maynooth University
Evaluation of animal and plant diversity suggests Greenland’s thaw hastens the biodiversity crisis
Abstract Rising temperatures can lead to the occurrence of a large-scale climatic event, such as the melting of Greenland ice sheet, weakening the AMOC and further increasing dissimilarities between current and future climate. The impacts of such an event are still poorly assessed. Here, we evaluate those impacts across megadiverse countries on 21,146 species of tetrapods and vascular plants using the pessimistic climate change scenario (RCP 8.5) and four different scenarios of Greenland’s ice sheet melting. We show that RCP 8.5 emission scenario would lead to a widespread reduction in species’ geographic ranges (28–48%), which is projected to be magnified (58–99%) with any added contribution from the melting of Greenland. Also, declines in the potential geographical extent of species hotspots (12–89%) and alterations of species composition (19–91%) will be intensified. These results imply that the influence of a strong and rapid Greenland ice sheet melting, resulting in a large AMOC weakening, can lead to a faster collapse of biodiversity across the globe.
(Communications Biology. vol. 5, n° 2399-3642, pp. 985, 01/12/2022)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
New insights into detecting alizarin from autofluorescence in marked glass eels
Alizarin detection in fish fins is extensively employed because it is easy to use. However, in eels, the eelGFP fluorescent protein may impede the detection of the fluorescent markers in the eel tissues. The study tests the effectiveness of three of the most up-to-date alizarin-detecting technologies on the living body and fins of European glass eels ( Anguilla anguilla L.). The findings demonstrated that the control group had a high autofluorescence at alizarin and eelGFP maxima bands. With fluorescence reflectance imaging (FRI), the eel living body autofluorescence impeded the detection of the marked eels. In contrast with experimental excitation-emission-matrix (EEM) fluorescence analyses, 99% of the marked eels were correctly assigned to their group from fluorescence analyses of their fin cellular contents. With epifluorometry (EPI), 100% of the marked eels were detected with the caudal fin tips when excited at 450–490 nm wavelengths due to a weaker autofluorescence signal. EEM and FRI assays unveiled an average fluorescence quenching 60% and 44% of the marked group respectively, in the alizarin and eelGFP maxima bands. The fluorescence quenching observed is discussed. Results will benefit experimental design by examining autofluorescence effects on mark detection and the development of non-invasive detection methods in this critically endangered species.
(Scientific Reports. vol. 12, n° 2045-2322, pp. 15985, 01/12/2022)
UR EABX, INRAE, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, IMOTION, UB