Chemical characterization and stable carbon isotopic composition of particulate Polycyclic Aromatic Hydrocarbons issued from combustion of 10 Mediterranean woods
The objectives of this study were to characterize polycyclic aromatic hydrocarbons from particulate matter emitted during wood combustion and to determine, for the first time, the isotopic signature of PAHs from nine wood species and Moroccan coal from the Mediterranean Basin. In order to differentiate sources of particulate-PAHs, molecular and isotopic measurements of PAHs were performed on the set of wood samples for a large panel of compounds. Molecular profiles and diagnostic ratios were measured by gas chromatography/mass spectrometry (GC/MS) and molecular isotopic compositions (δ13C) of particulate-PAHs were determined by gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS). Wood species present similar molecular profiles with benz(a)anthracene and chrysene as dominant PAHs, whereas levels of concentrations range from 1.8 to 11.4 mg g−1 OC (sum of PAHs). Diagnostic ratios are consistent with reference ratios from literature but are not sufficient to differentiate the species of woods. Concerning isotopic methodology, PAH molecular isotopic compositions are specific for each species and contrary to molecular fingerprints, significant variations of δ13C are observed for the panel of PAHs. This work allows differentiating wood combustion (with δ13CPAH = −28.7 to −26.6‰) from others origins of particulate matter (like vehicular exhaust) using isotopic measurements but also confirms the necessity to investigate source characterisation at the emission in order to help and complete source assessment models. These first results on woodburnings will be useful for the isotopic approach to source tracking.
(Atmospheric Chemistry and Physics. vol. 13, n° 1680-7316, pp. 2703-2719, 19/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LCE, AMU, INC-CNRS, CNRS
Northward advection of Atlantic water in the eastern Nordic Seas over the last 3000 yr
Three marine sediment cores distributed along the Norwegian (MD95-2011), Barents Sea (JM09-KA11-GC), and Svalbard (HH11-134-BC) continental margins have been investigated in order to reconstruct changes in the poleward flow of Atlantic waters (AW) and in the nature of upper surface water masses within the eastern Nordic Seas over the last 3000 yr. These reconstructions are based on a limited set of coccolith proxies: the abundance ratio between Emiliania huxleyi and Coccolithus pelagicus, an index of Atlantic vs. Polar/Arctic surface water masses; and Gephyro-capsa muellerae, a drifted coccolith species from the temperate North Atlantic, whose abundance changes are related to variations in the strength of the North Atlantic Current. The entire investigated area, from 66 to 77 • N, was affected by an overall increase in AW flow from 3000 cal yr BP (before present) to the present. The long-term modulation of westerlies' strength and location, which are essentially driven by the dominant mode of the North Atlantic Oscillation (NAO), is thought to explain the observed dynamics of poleward AW flow. The same mechanism also reconciles the recorded opposite zonal shifts in the location of the Arctic front between the area off western Norway and the western Barents Sea-eastern Fram Strait region. The Little Ice Age (LIA) was governed by deteriorating conditions, with Arctic/Polar waters dominating in the surface off western Svalbard and western Barents Sea, possibly associated with both severe sea ice conditions and a strongly reduced AW strength. A sudden short pulse of resumed high WSC (West Spitsbergen Current) flow interrupted this cold spell in eastern Fram Strait from 330 to 410 cal yr BP. Our dataset not only confirms the high amplitude warming of surface waters at the turn of the 19th century off western Svalbard, it also shows that such a warming was primarily induced by an excess flow of AW which stands as unprecedented over the last 3000 yr.
(Climate of the Past. vol. 9, n° 1814-9324, pp. 1505-1518, 19/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UiT, GEOTOP, UQAM
Caged Gammarus fossarum (crustacea) as a robust tool for the characterization of bioavailable contamination levels in continental waters. Toward the determination of threshold values
We investigated the suitability of an active biomonitoring approach, using the ecologically relevant species Gammarus fossarum, to assess trends of bioavailable contamination in continental waters. Gammarids were translocated into cages at 27 sites, in the Rhône-Alpes region (France) during early autumn 2009. Study sites were chosen to represent different physico-chemical characteristics and various anthropic pressures. Biotic factors such as sex, weight and food availability were controlled in order to provide robust and comparable results. After one week of exposure, concentrations of 11 metals/metalloids (Cd, Pb, Hg, Ni, Zn, Cr, Co, Cu, As, Se and Ag) and 38 hydrophobic organic substances including polycyclic aromatic hydrocarbons (PAHs), polychlorobiphenyles (PCBs), pentabromodiphenylethers (PBDEs) and organochlorine pesticides, were measured in gammarids. All metals except Ag, and 33 organic substances among 38 were quantified in G. fossarum, showing that this species is relevant for chemical biomonitoring. The control of biotic factors allowed a robust and direct inter-site comparison of the bioavailable contamination levels. Overall, our results show the interest and robustness of the proposed methodological approach for assessing trends of bioavailable contamination, notably for metals and hydrophobic organic contaminants, in continental waters. Furthermore, we built threshold values of bioavailable contamination in gammarids, above which measured concentrations are expected to reveal a bioavailable contamination at the sampling site. Two ways to define such values were investigated, a statistical approach and a model fit. Threshold values were determined for almost all the substances investigated in this study and similar values were generally derived from the two approaches. Then, levels of contaminants measured in G. fossarum at the 27 study were compared to the threshold values obtained using the model fit. These threshold values could serve as a basis for further implementation of quality grids to rank sites according to the extent of the bioavailable contamination, with regard to the applied methodology.
(Water Research. vol. 47, n° 0043-1354, pp. p. 650 - p. 660, 19/04/2026)
UR MALY, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
On the use of the radon transform in studying wave dynamics
In nearshore studies, there is an increasing interest for describing wave-by-wave dynamics. Most existing methods compute bulk parameters for celerity and the separation of incoming and outgoing waves. In this paper we address the use of the Radon Transform for studying wave dynamics. The Radon Transform is a projection of a bidimensional field (e.g. spatiotemporal wave signal) into polar coordinates which can be back projected at given angles. The method is applied to laboratory low-sloping beach and non-linear waves GLOBEX dataset. The separation of incoming from outgoing long waves using Radon is tested and compared to the method described in Guza et al., (1984). Components are retrieved, even at standing long wave nodes. Individual short wave celerity derived from Radon is found in agreement with celerity derived from tracked individual crest.
(pp. 73-82, 19/04/2026)
LEGOS, IRD, UT3, Comue de Toulouse, INSU - CNRS, CNES, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LEGI, UJF, Grenoble INP, CNRS, PUC, IMAU
Fate of micropollutants through various types of biofilm reactors
The present work details the results of a comprehensive study dealing with 127 priority and emerging micropollutants through various attached-growth biomass processes: rotating biodiscs, trickling filter, submerged biofilters. The research work involved powerful and sensitive analytical techniques to measure micropollutants concentrations in wastewaters in order to calculate robust removals by the various types of treatment and evaluate released micropollutant fluxes. This work also allowed pointing out the micropollutants that would require further treatment or source control.
(pp. 4, 19/04/2026)
UR MALY, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Comparative effects of three PAH fractions from light and heavy crude oils and from a PAH-contaminated sediment on Oryzias latipes Japanese medaka early life stages
(19/04/2026)
UB, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, BE, IFREMER
Climatic facilitation of the colonization of an estuary by Acartia tonsa
Global change has become a major driving force of both terrestrial and marine systems. Located at the interface between these two realms, estuarine ecosystems are probably the place where both direct and indirect effects of human activities conspire together to affect biodiversity from phytoplankton to top predators. Among European estuarine systems, the Gironde is the largest estuary of Western Europe and many studies have provided evidence that it has been affected by a variety of anthropogenic stressors such as thermal and chemical pollution, physical alterations and exploitation, especially for maritime traffic. In such a context, species introduction is also a current major issue with the establishment of strong competitive species that could lead to ecosystem reorganization with potential decrease or even disappearance of native species. In the Gironde estuary, this hypothesis was proposed for the invasive shrimp species Palaemon macrodactylus as a decrease in the native species abundance was observed at the same time. Although species introduction often takes place via ballast water, the influence of climate-driven changes on the establishment of new species remains a key issue. The calanoid copepod Acartia tonsa, observed in the Gironde estuary for the first time in 1983, have since colonized most part of the estuary, reaching a level of abundance comparable to the dominant native species Eurytemora affinis. In this study, using both the concept of the ecological niche sensu Hutchinson (fundamental and realized niches) and statistical models, we reveal that the dynamics of the colonization of A. tonsa was facilitated by environmental conditions that have become closer to its environmental optimum with respect to temperature and salinity.
(PLoS ONE. vol. 8, n° 1932-6203, pp. e74531, 19/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LOG, INSU - CNRS, ULCO, CNRS, IRD [Ile-de-France]
Observations of waves' impact on currents in a mixed-energy tidal inlet : Arcachon on the southern French Atlantic coast
Coastal morphodynamic processes around tidal inlets in mixed-energy environments are particularly complex due to severe tide and wave conditions. Collecting data in this area is generally very challenging . Here we present the first hydrodynamic data collected in the outer inlet of the Arcachon lagoon, a mixed-energy inlet situated on the southern part of the French Atlantic coast. Data consist in vertical current profiles and sea surface elevations collected on the offshore edge of the ebb delta under various tidal and wave conditions. In particular data were collected during the severe Joachim storm associated to wave heights up to 8 m. Preliminary results indicate that current profiles, intensities and direction are very sensitive to wave conditions. Under energetic conditions, the vertical profile of currents become uniform and the longshore drift is enhanced (up to 1.5 m/s). Nevertheless data show that under severe wave conditions (Hm0> 6.0m) and despite high incidence of waves, the longshore drift is weaker (l< 1 m/s) than under ‘usual’ storm conditions associated to Hm 0= 4–5m. More surprisingly, directions of the longshore drift are not always consistent with wave incidence under those severe storm conditions and the cross-shore components are very weak while under less energetic conditions we observe intense offshore currents(upto 0.8 m/s).
(Journal of Coastal Research, n° 0749-0208, pp. p. 2053-2058, 19/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, PRODIG, UP1, IRD, EPHE, PSL, UP4, UPD7, CNRS, SHOM
North-south palaeohydrological contrasts in the central Mediterranean during the Holocene: tentative synthesis and working hypotheses
On the basis of a multi-proxy approach and a strategy combining lacustrine and marine records along a north- south transect, data collected in the central Mediterranean within the framework of a collaborative project have led to reconstruction of high-resolution and well-dated palaeohydrological records and to assessment of their spatial and temporal coherency. Contrasting patterns of palaeohydrological changes have been evidenced in the central Mediterranean: south (north) of around 40 N of latitude, the middle part of the Holocene was characterised by lake-level maxima (minima), during an interval dated to ca. 10 300-4500 cal BP to the south and 9000-4500 cal BP to the north. Available data suggest that these contrasting palaeohydrological patterns operated throughout the Holocene, both on millennial and centennial scales. Regarding precipitation seasonality, maximum humidity in the central Mediterranean during the middle part of the Holocene was characterised by humid winters and dry summers north of ca. 40 N, and humid winters and summers south of ca. 40 N. This may explain an apparent conflict between palaeoclimatic records depending on the proxies used for reconstruction as well as the synchronous expansion of tree species taxa with contrasting climatic requirements. In addition, south of ca. 40 N, the first millennium of the Holocene was characterised by very dry climatic conditions not only in the eastern, but also in the central- and the western Mediterranean zones as reflected by low lake levels and delayed reforestation. These results suggest that, in addition to the influence of the Nile discharge reinforced by the African monsoon, the deposition of Sapropel 1 has been favoured (1) by an increase in winter precipitation in the northern Mediterranean borderlands, and (2) by an increase in winter and summer precipitation in the southern Mediterranean area. The climate reversal following the Holocene climate optimum appears to have been punctuated by two major climate changes around 7500 and 4500 cal BP. In the central Mediterranean, the Holocene palaeohydrological changes developed in response to a combination of orbital, ice-sheet and solar forcing factors. The maximum humidity interval in the south-central Mediterranean started ca. 10 300 cal BP, in correlation with the decline (1) of the possible blocking effects of the North Atlantic anticyclone linked to maximum insolation, and/or (2) of the influence of the remnant ice sheets and fresh water forcing in the North Atlantic Ocean. In the north-central Mediterranean, the lake-level minimum interval began only around 9000 cal BP when the Fennoscandian ice sheet disappeared and a prevailing positive NAO-(North Atlantic Oscillation) type circulation developed in the North Atlantic area. The major palaeohydrological oscillation around 4500- 4000 cal BP may be a non-linear response to the gradual decrease in insolation, with additional key seasonal and interhemispheric changes. On a centennial scale, the successive climatic events which punctuated the entire Holocene in the central Mediterranean coincided with cooling events associated with deglacial outbursts in the North Atlantic area and decreases in solar activity during the interval 11 700-7000 cal BP, and to a possible combination of NAO-type circulation and solar forcing since ca. 7000 cal BP onwards. Thus, regarding the centennial-scale climatic oscillations, the Mediterranean Basin appears to have been strongly linked to the North Atlantic area and affected by solar activity over the entire Holocene. In addition to model experiments, a better understanding of forcing factors and past atmospheric circulation patterns behind the Holocene palaeohydrological changes in the Mediterranean area will require further investigation to establish additional high-resolution and well-dated records in selected locations around the Mediterranean Basin and in adjacent regions. Special attention should be paid to greater precision in the reconstruction, on millennial and centennial timescales, of changes in the latitudinal location of the limit between the northern and southern laeohydrological Mediterranean sectors, depending on (1) the intensity and/or characteristics of climatic periods/oscillations (e.g. Holocene thermal maximum versus Neoglacial, as well as, for instance, the 8.2 ka event versus the 4 ka event or the Little Ice Age); and (2) on varying geographical conditions from the western to the eastern Mediterranean areas (longitudinal gradients). Finally, on the basis of projects using strategically located study sites, there is a need to explore possible influences of other general atmospheric circulation patterns than NAO, such as the East Atlantic-West Russian or North Sea-Caspian patterns, in explaining the apparent complexity of palaeoclimatic (palaeohydrological) Holocene records from the Mediterranean area.
(Climate of the Past. vol. 9, n° 1814-9324, pp. 2043-2071, 19/04/2026)
LCE, CNRS, UFC, UBFC, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, PALEOCEAN, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, IMBE, AU, AMU, CNRS, CNRS, OCCR, UNIBE, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, MSHE, CNRS, UFC, UBFC, GEOAZUR 6526, IRD, UPMC, UNS, INSU - CNRS, UniCA, CNRS, UNIROMA, GEOPS, UP11, CNRS, ISTO, BRGM, INSU - CNRS, UO, CNRS, UniPi, EAWAG, UNIMOL, M2C, UNICAEN, NU, INSU - CNRS, UNIROUEN, NU, CNRS, GEODE, UT2J, Comue de Toulouse, CNRS, D-ERDW, ETH Zürich, FSS
Benthic foraminifera from Capbreton Canyon revisited; faunal evolution after repetitive sediment disturbance
At a 650 m deep site in the axis of Capbreton Canyon an 18-cm-thick turbidite was deposited in December 1999. During subsequent campaigns, an almost monospecific fauna of the benthic foraminifer Technitella melo, considered as a pioneer species, was found in May 2000. In 2001 this fauna had disappeared and was replaced by an exceptionally rich fauna strongly dominated by the opportunistic species Bolivina subaenariensis. We present sedimentological, radionuclide and foraminiferal data of new cores, sampled in 2005 and 2011, taken with the aim to study the further evolution of the benthic ecosystem. Cores sampled in 2005 show that in the canyon axis a new, ca. 5 cm thick, turbidite has been deposited. The live benthic foraminiferal faunas were much poorer than in 2001, but still had a high dominance and low diversity, although less extreme than in 2001. We conclude that in the canyon axis, benthic foraminiferal faunas remain in an early stage of ecosystem colonization. It appears that the very thick 1999 turbidite marks an exceptional event. The uncommonly rich faunas observed in 2001 could be a response to the concentration of organic-rich material in the fine-grained top of this deposit. In 2011, cores were sampled at a slightly different site, on the lower canyon flank. The sedimentary sequence here is marked by the absence of coarse turbidite layers, although some levels show slightly increased grain size, and lower 210Pbxs activities, indicative of an admixture with advected older sediments. Live foraminiferal faunas are much more equilibrated, as shown by their higher diversity, lower dominance, and deeper penetration into the sediment. All these characteristics are indicative of a much more stable ecosystem. Dead faunas are present throughout the core, indicating that the levels with slightly elevated grain size are not typical turbidites resulting from hyperpycnal currents (which are characterized by levels barren of foraminifera) but denote other, more long-term sedimentary processes leading to the advection of older material, such as bottom nepheloid layers, or repetitive fine-grained turbidite deposits due to small-scale slumping. The comparison of live and dead fauna shows that at both sites, the foraminiferal turnover rates are fairly low. At the lower canyon flank site sampled in 2011, the foraminiferal faunas are renewed every 1.5–2 years. Such a fairly long foraminiferal lifespan corresponds to earlier estimates, but is surprisingly high for the opportunistic taxa that dominate the faunal assemblages in these unstable and food-enriched submarine canyon settings.
(Deep Sea Research Part II: Topical Studies in Oceanography. vol. 104, n° 0967-0645, pp. 319 - 334, 19/04/2026)
LPG-ANGERS, LPG, UA, UN UFR ST, UN, INSU - CNRS, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS