Contamination of ivory gulls (Pagophila eburnea) at four colonies in Svalbard in relation to their trophic behaviour
The ivory gull (Pagophila eburnea) is a high-Arctic species considered endangered in most parts of its breeding range. Ivory gulls must cope with not only the reduction in sea ice cover triggered by climate change but also increasing contaminant loads due to changes in global contaminant pathways and the release of previously stored pollutants from melting snow and ice. This top predator may be affected by biomagnification processes of a variety of compounds with concentrations dramatically increasing from water to higher trophic levels. The objective of this study was therefore to assess the contaminant bioaccumulation of this species in four colonies located on Barentsøya, Svalbard, in link with its trophic behaviour. To that end, contaminants, including organochlorines (OCs), brominated flame retardants (BFRs), and perfluorinated alkyl substances (PFASs), were determined in the blood (plasma and whole blood) of ivory gulls sampled over several years. Carbon- and nitrogen-stable isotopes were also determined in different tissues (feathers, plasma and red blood cells, or whole blood) to infer the trophic level (δ15N) and feeding habitat (δ13C) during both the breeding and moulting periods. The most quantitatively abundant contaminants found in the ivory gull were p,p’-DDE (dichlorodiphenyldichloroethylene), RPCB (polychlorobiphenyl), and PFOS (perfluorooctane sulphonate). Several compounds including most of the PFASs, trans-nonachlor, cis-nonachlor, and BDE-28 were correlated with nitrogen values. This study highlighted variability in trophic behaviour among individuals during the breeding and the moulting periods. Overall, similar feeding habitats and strategies were used between breeding sites which was echoed by similar contaminant levels.
(Polar Biology. vol. 40, n° 0722-4060, pp. 917 - 929, 01/04/2017)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LIENSs, INSU - CNRS, ULR, CNRS, NILU
Abrupt cooling over the North Atlantic in modern climate models
Observations over the 20th century evidence no long-term warming in the subpolar North Atlantic (SPG). This region even experienced a rapid cooling around 1970, raising a debate over its potential reoccurrence. Here we assess the risk of future abrupt SPG cooling in 40 climate models from the fifth Coupled Model Intercomparison Project (CMIP5). Contrary to the long-term SPG warming trend evidenced by most of the models, 17.5% of the models (7/40) project a rapid SPG cooling, consistent with a collapse of the local deep-ocean convection. Uncertainty in projections is associated with the models' varying capability in simulating the present-day SPG stratification, whose realistic reproduction appears a necessary condition for the onset of a convection collapse. This event occurs in 45.5% of the 11 models best able to simulate the observed SPG stratification. Thus, due to systematic model biases, the CMIP5 ensemble as a whole underestimates the chance of future abrupt SPG cooling, entailing crucial implications for observation and adaptation policy.
(Nature Communications. vol. 8, n° 2041-1723, pp. 14375, 01/04/2017)
LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, KNMI, I2M-BX, UB, CNRS, INRAE
Simulating wave setup and runup during storm conditions on a complex barred beach
The purpose of this study is to assess the ability of the SWASH model to reproduce wave setup and runup in highly dissipative stormy conditions. To proceed we use data collected during the ECORS Truc Vert’08 Experiment, especially during the Johanna storm in the winter of 2007-008 (wave setup under Hs= 8.2 m and Tp= 18.3 s and runup under 6.4 m and peak period up to 16.4 s). We test different model settings (1D and 2D mode) and model forcing (spectral and parametric) to reproduce sensor measured wave setup at several locations in the nearshore area and video measured runup on two beach profiles. For the whole tested configurations, the wave setup is reproduced accurately. Results considering all the sensor locations in the near shore area in 1D and 2D are significantly correlated to the observations with respectively ρ²=0.66 and 0.81; RMSE=0.13 m and 0.08 m without any significant bias. Observations and simulations of runup are investigated in terms of spectra and statistic component. 1D simulations produces an overall overestimation and no significant improvement is obtained by modifying the breaking parameters. The results for 2D simulations are fairly satisfactory reproducing significant swash height (S ), but are significantly improved with spectral forcing than parametric with respectively ρ²=0.73 and 0.71, RMSE=0.19 m and 0.43 m. Generally, the model reproduces accurately the infragravity component but tends to overestimate the incident component, leading to an overestimation of the energy density for moderate wave conditions and more accurate results for higher-energy wave conditions. Results in 2D with spectral forcing show a saturation of the infragravity component with a threshold around Hs=4 to 5 m, which is comparable to the observations collected at Truc Vert Beach. As regards the conventional statistical parameter for runup estimation (R2%) three methods are applied to derive the 2% exceedence value for runup from observed and simulated shoreline vertical elevation time series. When R2% is based on the sum of wave setup and half of the significant swash height, results provided by the model are close or even better than estimations provided by empirical formulas from the bibliography. Defining R2% as the exceeded 2% values of the time, derived considering the cumulative distribution function of the entire water-level time series also provide fairly good results. Results using only runup maxima time series are less satisfactory. In the two last cases, R2% is slightly underestimated for moderate wave conditions (Hs<4 m; Tp ≈ 14 s) and overestimated for higher-energy wave conditions. Generally results shows that where extreme wave conditions are concerned, the model setting must be considered carefully because the simplification of 1D (rather than 2D), or the use of parametric wave description (rather than spectral), can be a source of significant inaccuracy or overestimation in simulated run-up values.
(Coastal Engineering. vol. 123, n° 0378-3839, pp. 29-41, 31/03/2017)
BRGM, UB, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Do Temporal and Spatial Parameters or Lifestyle of the Pacific Oyster Crasssostrea gigas Affect Pollutant Bioaccumulation, Offspring Development, and Tolerance to Pollutants?
This study evaluated the vulnerability of early life stages of native oysters (Crassostrea gigas) from the Arcachon Bay (SW, France) to pollutants at risk in the lagoon in particular copper and S-metolachlor. Developmental abnormalities in wild and cultivated oyster D-larvae were investigated during 2 breeding-seasons (2013 and 2014) at different sampling sites and dates. In addition, copper, and metolachlor concentrations were determined both in seawater and in mature oysters. Bioaccumulation of Cu was observed at higher levels in wild than in farmed specimens. Metolachlor was accumulated at much lower levels. After 24 h exposure, significant increases of the percentage of abnormal D-larvae were observed when exposed at 1 μg L−1 of copper or 10 ng L−1 of metolachlor in comparison with the controls whatever the date, the site, and rearing conditions of the genitors. The current study demonstrates that environmental concentrations of copper and metolachlor can induce a significant increase of developmental abnormalities in farmed and wild populations of oysters. However, no significant differences of sensitivity were observed according to temporal, spatial parameters, and lifestyle of genitors. In addition, oyster larvae obtained from the hatchery displayed the same sensitivity to pollutants as larvae from the field, demonstrating their suitability for toxicity assays and water quality monitoring.
(Frontiers in Marine Science. vol. 4, n° 2296-7745, 16/03/2017)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Foredune morphological changes and beach recovery from the extreme 2013/2014 winter at a high-energy sandy coast
The beach-dune response at Truc Vert, SW France, is analysed using DGPS topographic surveys sampled every 2–4 weeks covering an alongshore distance of 1.5 km, combined with wave, tide and extreme water level hindcast and beach/dune photographs. During the 2013/2014 winter, which was the most energetic since at least 1948, the beach-dune system at Truc Vert eroded by approximately 180 m3 per beach width divided equally between beach and dune erosion. Beach and dune erosion was strongly variable alongshore, with cuspate-type rhythmic dune erosion scarps stripped of vegetation with a cross-shore amplitude of 25 m. The alongshore-variable scarps were coupled with an alongshore variability in elevation of the beach, with lower beach levels co-located with the megacusp bays. The following 10 months showed modest morphological beach and dune changes with, for instance, destabilisation of the scarped dune by trough blowouts, scarp slumping and filling and seasonal beach berm dynamics. The most profound morphological and vegetation changes occurred during the subsequent 10 months. Only 1.5 years after that winter, the beach-dune system at Truc Vert almost recovered to its pre-winter volume, but not to its pre-winter foredune profile. Most of the sand volume recovery occurred during spring-summer-autumn 2015 when approximately 120 m3/m of sand naturally came back in the system. The beach volume recovery rate was relatively steady and uncorrelated with wave conditions, with rates twice as large across the megacusp bay profile as across the that of the megacusp horns. During that period, the widened and risen dry beach provided large fetch length enhancing onshore windblown transport and a rapid rising of the backshore. The slumped and filled dune scarp, which was providing a high barrier to aeolian transport from the beach to the dune since the 2013/2014 winter, reformed as a dune ramp providing efficient conduit for beach-dune delivery/exchange of sediment by the end of the study. This process favoured both natural revegetation into the scarp and incipient foredune formation. Despite the reinstatement of natural processes between the beach and the dune, the dune foot was still located landward by more than 10 m on average with respect to its pre-2013/2014 winter position. This study shows that even after the most severe winter over the last 68 years in terms of average wave energy arriving at the coast, beach recovery can be a relatively fast process along high-energy sandy beaches backed by large dunes. In contrast foredune recovery, which timing and magnitude can provide a proxy measure for the resilience of the system to climatic variability and change, is a much slower process that can take years to decades.
(Marine Geology. vol. 385, n° 0025-3227, pp. 41-55, 01/03/2017)
CNRS, UB, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, OASU, UB, INSU - CNRS, ULR, CNRS, INRAE, LETG - Brest, LETG, UNICAEN, NU, UA, EPHE, PSL, UBO EPE, UR2, CNRS, IGARUN, UN
Development of a multi-residue method for scrutinizing psychotropic compounds in natural waters
The present work describes a multi-residue SPE-UPLC–MS/MS method aiming at the characterization of 68 compounds in natural waters, including parent compounds as well as their major metabolites and glucuronide conjugates. Development was conducted toward the quantitative determination of a broad range of analytes belonging to different class of psychotropic drugs such as benzodiazepines, antidepressants, stimulants, opiates and opioids, anticonvulsants, anti-dementia drugs, analgesic and anti-inflammatory drugs (as anthropic indicators) in the low ng L−1 range of concentration. Satisfactory extraction recoveries >70% were obtained for the majority of analytes (49 out of 68) allowing low limits of quantification. LOQ ranged between 0.1 and 17.8 ng L−1 and were lower than 5 ng L−1 for 94% of investigated analytes. Furthermore, addition of 25 isotopic labeled standards allowed to ensure reliability of the optimized method. Quantification errors were typically below 15% with relative standard variations <10% in intermediate precision conditions. Finally, the developed method was implemented in natural waters; sampling campaigns were conducted in the Seine River as a demonstration of the applicability and adequation of the method for its purpose. As a result, 48 out of 68 analytes were identified or quantified; some of them like memantine, rivastigmine, zolpidem 4-phenyl-carboxylic acid, zolpidem 6-carboxylic acid for one of the first time in surface waters. Among investigated psychotropic compounds and metabolites, tramadol, codeine, oxazepam, venlafaxine, O-desmethylvenlafaxine, gabapentin, carbamazepine and 10,11-dihydro-10,11-dihydroxycarbamazepine were found to be the most abundant.
(Journal of Chromatography B Biomedical Sciences and Applications. vol. 1047, n° 0378-4347, pp. 160-172, 01/03/2017)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Chaetozone corona (Polychaeta, Cirratulidae) in the Bay of Biscay: a new alien species for the North-east Atlantic waters?
The cirratulid species Chaetozone corona is reported for the first time from the North-east Atlantic waters. Several specimens were collected during oceanographic surveys between 1996 and 2015 from soft bottom habitats along the coasts of Brittany (Western France). This species, originally described from the coast of California, was recently recorded for the first time from the Mediterranean Sea. We hypothesize that this species could have been recently introduced to the Atlantic coasts of Europe and colonized the northern coast of Bay of Biscay from the Loire estuary to the Iroise Sea. We discuss the potential vectors of introduction and the main environmental factors that could explain its current distribution. An identification key to all the known North-east Atlantic species of Chaetozone is given.
(Journal of the Marine Biological Association of the United Kingdom. vol. 97, n° 0025-3154, pp. 433-445, 01/03/2017)
IUEM, IRD, INSU - CNRS, UBO EPE, CNRS, LIENSs, INSU - CNRS, ULR, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LEP, EEP, IFREMER
Epigenetic, histopathological and transcriptomic effects following exposure to depleted uranium in adult zebrafish and their progeny
(Aquatic Toxicology. vol. 184, n° 0166-445X, pp. 14-25, 01/03/2017)
IRSN, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, CIBEST, SYMMES, INC-CNRS, CNRS, UGA [2016-2019], IRIG, DRF (CEA), KIT, C3R, IRSN, CNRS
Toxicity effects of an environmental realistic herbicide mixture on the seagrass Zostera noltei
Worldwide seagrass declines have been observed due to multiple stressors. One of them is the mixture of pesticides used in intensive agriculture and boat antifouling paints in coastal areas. Effects of mixture toxicity are complex and poorly understood. However, consideration of mixture toxicity is more realistic and ecologically relevant for environmental risk assessment (ERA). The first aim of this study was to determine short-term effects of realistic herbicide mixture exposure on physiological endpoints of Zostera noltei. The second aim was to assess the environmental risks of this mixture, by comparing the results to previously published data. Z. noltei was exposed to a mixture of four herbicides: atrazine, diuron, irgarol and S-metolachlor, simulating the composition of typical cocktail of contaminants in the Arcachon bay (Atlantic coast, France). Three stress biomarkers were measured: enzymatic activity of glutathione reductase, effective quantum yield (EQY) and photosynthetic pigment composition after 6, 24 and 96 h. Short term exposure to realistic herbicide mixtures affected EQY, with almost 100% inhibition for the two highest concentrations, and photosynthetic pigments. Effect on pigment composition was detected after 6 h with a no observed effect concentration (NOEC) of 1 μg/L total mixture concentration. The lowest EQY effect concentration at 10% (EC10) (2 μg/L) and pigment composition NOEC with an assessment factor of 10 were above the maximal field concentrations along the French Atlantic coast, suggesting that there are no potential short term adverse effects of this particular mixture on Z. noltei. However, chronic effects on photosynthesis may lead to reduced energy reserves, which could thus lead to effects at whole plant and population level. Understanding the consequences of chemical mixtures could help to improve ERA and enhance management strategies to prevent further declines of seagrass meadows worldwide.
(Environmental Pollution. vol. 222, n° 0269-7491, pp. 393-403, 01/03/2017)
LEFE, INEE-CNRS, CNRS, UT3, Comue de Toulouse, CNRS, Toulouse INP, Comue de Toulouse, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LERAR, COAST, IFREMER
Photodegradation of sulfamethazine, sulfamethoxypiridazine, amitriptyline, and clomipramine drugs in aqueous media
The photochemical transformation of two antibacterial sulfonamides, namely sulfamethazine (SMT) and sulfamethoxypyridazine (SMP), and two tricyclic antidepressants, namely amitriptyline (AMT) and clomipramine (CMP) were investigated. Experiments conducted in river water under artificial sunlight irradiation show an acceleration of the degradation for SMT, SMP, and CMP of a factor 1.6–7.7 by comparison to purified water. This acceleration is, at least partially, due to photosensitized reactions which can occur in river water. The photodegradation of CMP was particularly fast. In addition, no degradation was observed for AMT in purified water while photosensitized reaction occurs. Under ultra-violet (254 nm) irradiation in purified water, the four drugs were degraded. Calculated quantum yields of photodegradation were of 4.3 × 10−3, 5.1 × 10−3, 7.6 × 10−3, and 65.0 × 10−3 respectively for SMT, SMP, AMT, and CMP. UV coupled with hydrogen peroxide (UV/H2O2) was used as an advanced oxidation process for water depollution. The calculated second order rate constants of reaction with hydroxyl radicals were of 5.0 × 109, 5.0 × 109, 8.0 × 109 and 9.5 × 109 L mol−1 s−1 for SMT, SMP, AMT and CMP, respectively. Finally, the structures of photoproducts were proposed according to LC–MS/MS analyses. The elimination of SO2 was the main photochemical process for SMT and SMP. In the case of AMT and CMP, hydration and hydroxylation, respectively, were observed.
(Journal of Photochemistry and Photobiology A: Chemistry. vol. 336, n° 1010-6030, pp. 176-182, 01/03/2017)
LAEC-CNRS, CNRS-L, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS