Impact of a SPG convection collapse on the European viticulture
(08/04/2018)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UMR EGFV, INRA, UB, Bordeaux Sciences Agro
Late frost risk for gravine in France
(08/04/2018)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UMR EGFV, INRA, UB, Bordeaux Sciences Agro
Noise pollution limits metal bioaccumulation and growth rate in a filter feeder, the Pacific oyster Magallana gigas
Shipping has increased dramatically in recent decades and oysters can hear them. We studied the interaction between noise pollution and trace metal contamination in the oyster Magallana gigas. Four oyster-groups were studied during a 14-day exposure period. Two were exposed to cadmium in the presence of cargo ship-noise ([Cd++]w ≈ 0.5 μg∙L-1; maximum sound pressure level 150 dBrms re 1 μPa), and 2 were exposed only to cadmium. The Cd concentration in the gills ([Cd]g) and the digestive gland ([Cd]dg), the valve closure duration, number of valve closures and circadian distribution of opening and closure, the daily shell growth-rate and the expression of 19 genes in the gills were studied. Oysters exposed to Cd in the presence of cargo ship-noise accumulated 2.5 times less Cd in their gills than did the controls without ship noise and their growth rate was 2.6 times slower. In the presence of ship noise, oysters were closed more during the daytime, and their daily valve activity was reduced. Changes in gene activity in the gills were observed in 7 genes when the Cd was associated with the ship noise. In the absence of ship noise, a change in expression was measured in 4 genes. We conclude that chronic exposure to cargo ship noise has a depressant effect on the activity in oysters, including on the volume of the water flowing over their gills (Vw). In turn, a decrease in the Vw and valve-opening duration limited metal exposure and uptake by the gills but also limited food uptake. This latter conclusion would explain the slowing observed in the fat metabolism and growth rate. Thus, we propose that cargo ship noise exposure could protect against metal bioaccumulation and affect the growth rate. This latter conclusion points towards a potential risk in terms of ecosystem productivity.
(PLoS ONE. vol. 13, n° 1932-6203, pp. e0194174, 04/04/2018)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, SoMAS, SBU, SUNY
In Situ Detection of Macronutrients and Chloride in Seawater by Submersible Electrochemical Sensors
(Analytical Chemistry. vol. 90, n° 0003-2700, pp. 4702-4710, 03/04/2018)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Comparison of living and dead benthic foraminifera on the Portuguese margin: Understanding the taphonomical processes
Dead benthic foraminifera (> 150 μm) were studied in 23 sediment cores from the Portuguese Margin at water depths between 20 and 2000 m and located on 4 transects off the Douro, Mondego, Tagus and Sado river mouths and 1 transect in the Estremadura. For 10 stations, the dead faunal vertical distribution (0–8 cm) was first investigated in 4 different sediment horizons per core to evaluate the sampling effort necessary to have a representation of the dead fauna deposited under different environmental areas. As a result, it appears that the faunal vertical distribution is constant, except for the deepest environments where fragile taxa were identified in the top layers only. Dead foraminiferal assemblages in the 4–5 cm layer for all stations were then compared to previously published living foraminiferal assemblages (of March 2011) from the same cores to evaluate the taphonomical processes affecting major species. This improves the knowledge of the faunal distribution for a better benthic foraminiferal proxy for paleostudies. There was a considerable loss of some species in the dead fauna. Firstly, this concerns the fragile organic-cemented agglutinated taxa such as Reophax spp., Glomospira charoides, or Bathysiphon spp. Secondly, some calcitic species such as Nonion scaphum, Cancris auriculus, Ammonia beccarii or Bulimina aculeata that were particularly abundant in the living fauna on the inner shelf under the late winter high river discharge conditions, were also far less dominant in the dead fauna. Lastly, other species like Cassidulina carinata, Valvulineria bradyana, and Bulimina marginata systematically showed higher abundance in the dead fauna at the mid shelf. These species, related to eutrophic conditions occurring in summer during the upwelling activity, were therefore not well represented in the living fauna, collected in March. Transport of allochthonous specimens may also account for higher contribution in the dead community of some species like Cibicides lobatulus, Asterigerinata mamilla or Haynesina depressula, especially in coastal environments where hydrodynamic processes (river flood, winter storm, coastal drift) are more vigorous. Several species (U. mediterranea, U. bifurcata, T. agglutinans, H. balthica or B. costata), however, show little or no difference in both abundance and spatial occurrence between the living and dead faunas and provide a stable signal for paleoclimatic investigations.
(Marine Micropaleontology. vol. 140, n° 0377-8398, pp. 1-16, 01/04/2018)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Current opinion: What is a nanoplastic?
With the large amount of attention being given to microplastics in the environment, several researchers have begun to consider the fragmentation of plastics down to lower scales (i.e., the sub-micrometer scale). The term “nanoplastics” is still under debate, and different studies have set the upper size limit at either 1000 nm or 100 nm. The aim of the present work is to propose a definition of nanoplastics, based on our recently published and unpublished research definition of nanoplastics. We define nanoplastics as particles unintentionally produced (i.e. from the degradation and the manufacturing of the plastic objects) and presenting a colloidal behavior, within the size range from 1 to 1000 nm.
(Environmental Pollution. vol. 235, n° 0269-7491, pp. 1030-1034, 01/04/2018)
GR, UR, INSU - CNRS, CNRS, Softmat, ICT, IRD, UT3, Comue de Toulouse, INC-CNRS, CNRS, Toulouse INP, Comue de Toulouse, UT3, Comue de Toulouse, INC-CNRS, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UPMC, CNRS, ISCR, UR, INSA Rennes, INSA, ENSCR, INC-CNRS, CNRS, IPREM, UPPA, INC-CNRS, CNRS
Usefulness of RTL-W1 and OLCAB-e3 fish cell lines and multiple endpoint measurements for toxicity evaluation of unknown or complex mixture of chemicals
Fish are currently used for the assessment of chemical toxicity. The REACh regulation and the European directive on the protection of animals used for scientific purposes both recommend the use of methods other than animal testing. In view of this, fish cell lines are increasingly used to provide fast and reliable toxic and ecotoxic data on new chemicals. The sensitivity of the Rainbow trout liver cell line RTL-W1 and Japanese medaka embryos cell line OLCAB-e3 were used with different toxicity endpoints, namely cytotoxicity, EROD activity, ROS production and DNA damage for various classes of pollutants displaying different modes of action but also with complex environmental mixtures. Toxicity tests were coupled with chemical analysis to quantify the chemical concentrations in cell cultures. Differences in sensitivity were found between fish cell lines. MTT reduction assay revealed that OLCAB-e3 cells were more sensitive than RTL-W1 cells. On the contrary, RTL-W1 gave higher response levels for the Fpg-modified comet assay and ROS assay. The OLCAB-e3 cell line did not express EROD activity unlike RTL-W1. This study highlights the capacity of the two different fish cell lines to measure the toxicity of individual toxicants but also environmental mixtures. Then, results obtained here illustrate the interest of using different cell lines and toxicity endpoints to assess the toxicity of complex or unknown mixture of chemicals.
(Ecotoxicology and Environmental Safety. vol. 150, n° 0147-6513, pp. 40-48, 01/04/2018)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Trophic transfer and effects of gold nanoparticles (AuNPs) in Gammarus fossarum from contaminated periphytic biofilm
This work addressed the trophic transfer and effects of functionalized gold nanoparticles (AuNPs) from periphytic biofilms to the crustacean Gammarus fossarum. Biofilms were exposed for 48 h to 10 nm positively charged functionalized AuNPs at two concentrations, 4.6 and 46 mg/L, and crustaceans G. fossarum grazed on these for 7 days, with daily biofilm renewal. Gold bioaccumulation in biofilm and crustacean were measured to estimate the trophic transfer ratio of these AuNP, and, for the first time, a transcriptomic approach and transmission electron microscopy observations in the crustacean were made. These two approaches showed cellular damage caused by oxidative stress and, in particular, an impact of these AuNPs on mitochondrial respiration. Modulation of digestive enzyme activity was also observed, suggesting modifications of digestive functions. The damage due to these nanoparticles could then have vital consequences for the organisms during chronic exposure.
(Environmental Science and Pollution Research. vol. 25, n° 0944-1344, pp. 11181-11191, 01/04/2018)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, ICMCB, UB, INC-CNRS, CNRS, SEBIO, INERIS, URCA, ULH, NU, URCA, CNRS, URCA, IRSTEA
Aragonite saturation state in a tropical coastal embayment dominated by phytoplankton blooms (Guanabara Bay – Brazil)
The dynamics of the aragonite saturation state (Ωarag) were investigated in the eutrophic coastal waters of Guanabara Bay (RJ-Brazil). Large phytoplankton blooms stimulated by a high nutrient enrichment promoted the production of organic matter with strong uptake of dissolved inorganic carbon (DIC) in surface waters, lowering the concentrations of dissolved carbon dioxide (CO2aq), and increasing the pH, Ωarag and carbonate ion (CO32 −), especially during summer. The increase of Ωarag related to biological activity was also evident comparing the negative relationship between the Ωarag and the apparent utilization of oxygen (AOU), with a very close behavior between the slopes of the linear regression and the Redfield ratio. The lowest values of Ωarag were found at low-buffered waters in regions that receive direct discharges from domestic effluents and polluted rivers, with episodic evidences of corrosive waters (Ωarag < 1). This study showed that the eutrophication controlled the variations of Ωarag in Guanabara Bay.
(Marine Pollution Bulletin. vol. 129, n° 0025-326X, pp. 729 - 739, 01/04/2018)
UFF, UFRGS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LOCEAN, IPSL, ENS-PSL, PSL, UVSQ, UPMC, CEA, INSU - CNRS, X, IP Paris, CNES, CNRS, MNHN, IRD, UPMC, INSU - CNRS, CNRS
Assessment of Lemna minor (duckweed) and Corbicula fluminea (freshwater clam) as potential indicators of contaminated aquatic ecosystems: responses to presence of psychoactive drug mixtures
The pharmaceutical products are emerging pollutants continuously released into the environment, because they cannot be effectively removed by the wastewater treatment plants. In recent years, questions have been raised concerning the environmental risks related to these pollutants. The goal of this research was to evaluate the responses in Lemna minor after 7 days and in Corbicula fluminea after differing durations (1, 3, 7, and 19 days) of exposure to the psychoactive drug mixture (valproic acid, citalopram, carbamazepine, cyamemazine, hydroxyzine, oxazepam, norfluoxetine, lorazepam, fluoxetine, and sertraline) in different concentrations (0, 0 + ethanol, drug concentration (DC) 1 = river water concentration, DC2 = effluent concentration, and DC3 = 10× effluent concentration). In this aim, growth parameters of L. minor, gluthathione S-transferase (GSTs), catalase (CAT), ethoxyresorufin-O-deethylase (EROD) and/or gene expressions (pi-gst, cat, cytochrome P450 4 (cyp4), multidrug resistant 1 (mdr1), and superoxide dismutase (sod)) were measured. GST activities increased significantly in L. minor exposed to DC3, but no changes were found in CAT activity. In C. fluminea, EROD activity was induced significantly in both gill and digestive gland tissues after 3 days’ exposure to DC3, while a GST increase was observed only in digestive gland tissues, suggesting that these pharmaceuticals induced an oxidative effect. Gene expression analysis revealed transient transcriptomic responses of cyp4, sod, and mdr1 under drug concentrations 2 or 3 and no change of expression for the other genes (cat and pi-gst) or condition (environmental drug concentration) tested. Finally, the data reported in this study represent important ecotoxicological information, confirming that this enzyme family (cyp4, sod, and mdr1) may be considered as a sensible and early indicator of exposure to drugs and emphasizing the involvement of selected genes in detoxification pathways.
(Environmental Science and Pollution Research. vol. 25, n° 0944-1344, pp. 11192-11204, 01/04/2018)
BTSB, INUC, Comue de Toulouse, ENA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LCE, CNRS, UMLP