Micrometeorite mass flux measurement at Dome C, Antarctica
(18/03/2019)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, CSNSM, UP11, IN2P3, CNRS, IAS, UP11, INSU - CNRS, CNRS, CNES
Contour current imprints and contourite drifts in the Bahamian archipelago
(Sedimentology. vol. 66, n° 0037-0746, pp. 1192-1221, 18/03/2019)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, KFUPM, CEREGE, IRD, INRA, AMU, CdF (institution), INSU - CNRS, CNRS
Export Balance of Polybrominated Diphenyl Ethers at the Scale of the Charmoise Watershed (France)
Fire sources in indoor spaces keep increasing, especially because of the growing number of electrical and electronic equipment uses. To reduce the risks of fire, several chemicals, called flame retardants (FRs), are used particularly in brominated compounds (BFRs). Polybrominated biphenylethers (PBDEs) are widely used in industry to prevent fires. These compounds are part of the composition in many consumer products (textiles, electronics, plastics…) in order to reduce their flammability. They have a pronounced structural similarity with thyroid hormones and they are strongly suspected for being responsible of endocrine disruption processes. The pathways of PBDEs to surface waters are multiple: atmospheric inputs, releases of Waste Water Treatment Plant (WWTP), urban storm-water discharge (USD), leaching or erosion of contaminated soils (atmospheric route or following urban sludge amendments). To identify the relative importance of each source of inputs in PBDE at the level of a peri-urban elemental catchment area, a flow assessment was carried out at the level of the basin of the Charmoise, France.
(Advances in Science, Technology & Innovation, n° 2522-8714, pp. 117-120, 15/03/2019)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, METIS, EPHE, PSL, INSU - CNRS, SU, CNRS
Evaluating ice‐rafted debris as a proxy for glacier calving in Upernavik Isfjord, NW Greenland
Records of ice‐rafted debris (IRD) in sediments are commonly used as a proxy for iceberg production and to reconstruct past changes of glacier stability. However, the interpretation of IRD is complex as multiple processes modulate its variability. This study investigates the relationship between IRD variability and glaciological change by measuring IRD records from Upernavik Fjord and comparing these to frontal positions of Upernavik Isstrøm during the past century. Results show that the spatial variability of IRD deposition throughout the fjord is high, indicating that randomness inherent to IRD distorts the calving signal. However, we investigate whether IRD records can be combined to improve the reconstruction, as previously suggested, and show the importance of core site selection and number of cores on this approach. The outer‐fjord core compares relatively well to the observed front positions and this is reflected in the composite record: increased IRD deposition in 1937–1946, 1968–1980, and 1996–1999 occurred during periods of faster retreat. Comparison with climatic records shows that the calving episodes in the late ‘30 s/early ‘40 s and late ‘90 s are related to warm ocean and air temperatures, whereas intensified retreat and calving during the ‘70 s reflects partly an internal glacier response to the fjord geometry.
(Journal of Quaternary Science. vol. 34, n° 0267-8179, pp. 258-267, 12/03/2019)
GEUS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Dietary exposure of mussels to PVP/PEI coated Ag nanoparticles causes Ag accumulation in adults and abnormal embryo development in their offspring.
Toxicity of silver nanoparticles (Ag NPs) to aquatic organisms has been widely studied. However, the potential toxic effects of Ag NPs ingested through the food web, especially at environmentally relevant concentrations, as well as the potential effects on the offspring remain unknown. The aims of this work were to screen the cytotoxicity of Poly N‑vinyl‑2‑pirrolidone/Polyethyleneimine (PVP/PEI) coated 5 nm Ag NPs in hemocytes exposed in vitro and to assess the effects of dietary exposure to Ag NPs on mussels growth, immune status, gonad condition, reproductive success and offspring embryo development. For this, mussels Mytilus galloprovincialis were fed daily with microalgae Isochrysis galbana previously exposed for 24 h to a dose close to environmentally relevant concentrations (1 μg Ag/L Ag NPs) and to a high dose of 10 μg Ag/L Ag NPs. After 24 h of in vitro exposure, Ag NPs were cytotoxic to mussel hemocytes starting at 1 mg Ag/L (LC50: 2.05 mg Ag/L). Microalgae significantly accumulated Ag after the exposure to both doses and mussels fed for 21 days with microalgae exposed to 10 μg Ag/L Ag NPs significantly accumulated Ag in the digestive gland and gills. Sperm motility and fertilization success were not affected but exposed females released less eggs than non-exposed ones. The percentage of abnormal embryos was significantly higher than in control individuals after parental exposure to both doses. Overall, results indicate that Ag NPs taken up through the diet can significantly affect ecologically relevant endpoints such as reproduction success and embryo development in marine mussels.
(Science of the Total Environment. vol. 655, n° 0048-9697, pp. 48-60, 10/03/2019)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Rare Earth Element fluxes over 15 years into a major European Estuary (Garonne-Gironde, SW France): Hospital effluents as a source of increasing gadolinium anomalies
New and rapidly developing technologies imply the emission of emerging potentially toxic contaminants such as Rare Earth Elements (REEs). Yet, the lithology-derived quantities and anthropogenic contributions, especially from urban areas, to annual REE fluxes into fluvial-estuarine systems remain widely unknown. The Garonne River drains water from ~20% of the French land surface hosting about 5,200,000 inhabitants and two large cities. Based on long-term monitoring (2003–2017) of water discharges and dissolved REEs concentrations at the outlet of the Garonne Watershed upstream from Bordeaux, this study aims at assessing REE anomalies and evaluating temporal evolution of annual dissolved REE fluxes into the Gironde Estuary. Additionally, potential urban sources (e.g. domestic, medical) in the urban area of Bordeaux (1,190,000 inhab.) were analyzed to evaluate respective signatures and contributions. Gadolinium (Gd) showed clear anomalies in all samples, with annual average anthropogenic concentrations ranging from 1.8 to 7.2 ng·L−1 (0.011 to 0.046 nmol·L−1) in the Garonne River. If variations in annual Gd fluxes depend on hydrology, anthropogenic Gd fluxes have shown an overall increasing trend from 32 kg·year−1 (204 mol·year−1) in 2003 to 75 kg·year−1 (475 mol·year−1) in 2017. Sewer waters from the third largest hospital complex of France, the hospital group Pellegrin, contributed 25% to the incoming daily Gd flux into Bordeaux major Waste Water Treatment Plant (WWTP), owed to Gd use as contrast agent for Magnetic Resonance Imaging (MRI). Due to weak removal efficiency in the WWTP, the Bordeaux Metropole significantly contributes (>27 kg·year−1; 172 mol·year−1) to Gd fluxes in the Gironde Estuary. The temporal evolution of anthropogenic Gd fluxes in the Garonne River may be related with the growing regional population and the increasing number of MRI instruments, highlighting the importance of new high-tech applications in urban areas on contaminant fluxes and their potential harmful effects in fluvial-estuarine systems in the future.
(Science of the Total Environment. vol. 656, n° 0048-9697, pp. 409-420, 01/03/2019)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Intraspecific facilitation explains the spread of the invasive engineer Spartina anglica in Atlantic salt marshes
Questions Invasiveness depends in part on the ability of exotic species to either exclude native dominants or to fill an empty niche. Comparisons of niches and effects of closely related native and invasive species enable the investigation of this topic. Does Spartina anglica invade European salt marshes through competitive exclusion of the native Spartina maritima or due to the occurrence of an empty ecological niche in highly anoxic conditions? Study Site The Arcachon Bay (France). Methods At three intertidal levels, we quantified competitive response and effect abilities of the two species through a cross-transplantation removal experiment. We also compared the biomass, root/shoot ratio, productivity and environmental conditions (elevation, salinity, redox potential and soil moisture) of salt marsh communities dominated by the exotic Spartina anglica or the native Spartina maritima at three intertidal levels. Results Both established species showed similar biotic resistance to the invasion of the other species, but the exotic showed important intraspecific facilitation for growth. Species had similar niches and total biomass along a gradient of anoxic conditions, but the exotic had a much higher root/shoot ratio and productivity than the native. Owing to its rhizome density, the exotic showed high ability to increase sediment oxygenation, likely to explain its important intraspecific facilitation. Conclusions Our results showed that the invasion success of S. anglica cannot be explained by the competitive exclusion of the native or by its ability to fill an empty niche along a gradient of anoxia. Its behaviour as a self-facilitator invasive engineer very likely explains its rapid spread in the Bay and biotic resistance to the colonization of other congeneric species when established in dense patches. Additionally, we suggest that physical disturbance in marsh communities dominated by the native S. maritima may disrupt its biotic resistance against the invasion of S. anglica.
(Journal of Vegetation Science. vol. 30, n° 1100-9233, pp. 212-223, 01/03/2019)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Typologie des habitats marins benthiques de la Manche, de la Mer du Nord et de l'Atlantique - VERSION 3
Ce rapport présente la version actualisée de la partie « Atlantique » du référentiel national des habitats marins benthiques en expliquant les modifications opérées. La mise à jour de la partie marine du référentiel européen EUNIS ainsi que les échanges avec les benthologues ont conduit à revoir les principes généraux de la typologie. La structure hiérarchique a été modifiée en débutant au premier niveau par des combinaisons de l’étagement et des types de substrat et ce, de manière à être le plus proche possible de la nouvelle version d’EUNIS. A la suite de ce premier niveau, révisé intégralement, les habitats listés dans la précédente version de la typologie ont été replacés au sein de la combinaison étage/substrat pertinente. Un effort particulier a été réalisé pour définir et homogénéiser la terminologie utilisée. La typologie a été complétée par de nouveaux habitats émanant de la bibliographie et de propositions directes d’experts. Enfin, les points nécessitant l’acquisition de nouvelles connaissances scientifiques sont également mentionnés.
(pp. 52 pages, 01/03/2019)
PatriNat, MNHN, CNRS, AFB, AD2M, SU, CNRS, SBR, SU, CNRS, DYNECO, IFREMER, ISYEB, MNHN, EPHE, PSL, SU, CNRS, UA, M2C, UNICAEN, NU, INSU - CNRS, UNIROUEN, NU, CNRS, ABICE, AD2M, SU, CNRS, SBR, SU, CNRS, IFREMER, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LERAR, COAST, IFREMER, DGD.REVE, MNHN, SBR, SU, CNRS, FR2424, SBR, SU, CNRS, LEP, EEP, IFREMER, LIENSs, INSU - CNRS, ULR, CNRS, ECOMAP, AD2M, SU, CNRS, SBR, SU, CNRS
Feeding ethology and surface sediment reworking by the ampharetid polychaete Melinna palmata Grube, 1870: Effects on sediment characteristics and aerobic bacterial community composition
(Journal of Experimental Marine Biology and Ecology. vol. 512, n° 0022-0981, pp. 63-77, 01/03/2019)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, NutriNeuro, INRA, UB, LOBB, OOB, UPMC, CNRS, UPMC, INSU - CNRS, CNRS
Transcriptome-wide analysis of wild Asari (=Manila) clams affected by the Brown Muscle Disease: Etiology and impacts of the disease
Recently, we reported an emerging pathology named Brown Muscle Disease (BMD) affecting Asari clams inhabiting the most productive area for this species in France, the Arcachon Bay. The main macroscopic feature of the pathology relies on the atrophy of the posterior adductor muscle, affecting the ability of clams to burry. The research of the etiological agent of BMD privileged a viral infection. Contrary to healthy clams, infected animals are always found at the surface of the sediment and exhibit 30 nm virus-like particles in muscle, granulocytic and rectal cells. In order to get more insights on the etiology and impacts of the BMD on clams, we took advantage in the present study of next generation sequencing technologies. An RNA-Seq approach was used (i) to test whether viral RNA sequences can be specifically found in the transcriptome of diseased animals and (ii) to identify the genes that are differentially regulated between diseased and healthy clams. Contrary to healthy buried animals, in diseased clams one sequence showing extensive homologies with retroviridae-related genes was detected. Among the biological processes that were affected in diseased clams, the synaptic transmission process was the most represented. To deepen this result, a new sampling was carried out and the transcription level of genes involved in synaptic transmission was determined in healthy and diseased clams but also in clams with no visible sign of pathology but located at the surface of the sediment. Our findings suggest that muscle atrophy is a latter sign of the pathology and that nervous system could be instead a primary target of the BMD agent.
(Fish and Shellfish Immunology. vol. 86, n° 1050-4648, pp. 179-185, 01/03/2019)
µVIS X-ray Imaging Centre, VIM (UR 0892), INRA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS