Climatically-controlled siliceous productivity in the eastern Gulf of Guinea during the last 40 000 yr
Opal content and diatom assemblages were analysed in core GeoB4905-4 to reconstruct siliceous productivity changes in the eastern Gulf of Guinea during the last 40 000 yr. Opal and total diatom accumulation rates presented low values over the considered period, except during the Last Glacial Maximum and between 15 000 calendar years Before Present (15 cal. ka BP) and 5.5 cal. ka BP, the so-called African Humid Period, when accumulation rates of brackish and freshwater diatoms at the core site were highest. Conversely, accumulation rates of windblown diatoms exhibited an opposite pattern with higher values before and after the African Humid Period and greatest values during Heinrich Events, the Younger Dryas and since 5.5 cal. ka BP. Our results demonstrate that siliceous productivity in the eastern Gulf of Guinea was directly driven by the nutrient load from local rivers, whose discharges were forced by precipitation changes over western Equatorial Africa and/or modification of the fluvio-deltaic systems forced by sea level changes. Precipitation in this region is controlled by the West African monsoon which is, in turn, partly dependent on the presence and intensity of the Atlantic Cold Tongue (ACT). Our results therefore suggest that the ACT was weakened, warmer trade winds were less vigorous, and cloud convec-tion and precipitation were greater during the AHP though centennial-to-millennial timescale dry events were observed at ∼10 cal. ka BP, ∼8.5 cal. ka BP and ∼6 cal. ka BP. Conversely , the ACT was more intense, trade winds were more vigorous and African climate was more arid during H1, the Younger Dryas and after 5.5 cal. ka BP into the present.
(Climate of the Past. vol. 8, n° 1814-9324, pp. 415-431, 28/10/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, IACT, CSIC, UGR, CAU
Remediation of a watershed contaminated by heavy metals: A 2-year field biomonitoring of periphytic biofilms
This study focuses on an industrial contamination site subjected to remediation processes since 2007 in the Riou-Mort watershed (southw st France). The purpose was to assess the first impacts of remediation on periphytic biofilms, and was performed during two years of biomonitoring. Periphytic biofilms were collected on glass slides immersed 24 days at different sites along the contamination gradient for 12 colonisation cycles. Metal contaminations (Cd and Zn) were analysed in biofilms and the evolution of diatom communities was assessed, integrating teratology quantifications. Despite remediation work initiated at the industrial site, this study demonstrated the persistence of metal contamination in water, as well as in biofilms. In addition, our data, showed that the remediation process was initially marked by an increase in metal contamination in the river, with increasing diatom community shifts. Metal-contaminated biofilms presented decreasing species diversities and were dominated by metal-resistant species such as Eolimna minima, whom abundances increased in 2010 reaching 57.2 ± 10%. No significant decrease in metal accumulation was observed and total Cd content in biofilms collected downstream the industrial site ranged from 772.7 ± 88 in July 2009 to 636.9 ± 20 μg/gDW in July 2 010. Results obtained on artificial substrates were compared with those of natural substrates and showed similar diatom communities and abundances of deformed diatoms but lower diversities. This ensured that glass slide subtrates gave a good representation of periphytic biofilm health . Finally, results were compared to studies performed before the remediation process and this did not reveal a decrease of metal accumulation in biofilms nor shifts in taxonomic composition of the communities, rather the remaining dominance of metal-resistant species such as E. minima was confirmed.
(Science of the Total Environment. vol. 425, n° 0048-9697, pp. 242-253, 28/10/2026)
UR REBX, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Evidence for a Complex Relationship between Antibiotics and Antibiotic-Resistant Escherichia Coli: From Medical Center Patients to a Receiving Environment
The aim of this study was to investigate the relationship between antibiotics and antibiotic-resistant fecal bacteria (E. coli) in water along a medical center−wastewater treatment plant−river continuum (4 km). A multiresidue chemical analysis methodology, using solid phase extraction coupled with liquid chromatography tandem mass spectrometry, was performed to detect whether low levels of contamination by 34 antibiotics were related to antibiotic resistance of E. coli and antibiotic use. The contamination of water by antibiotics and antibiotic-resistant E. coli decreased along the continuum. Although amoxicillin was predominantly prescribed, only ofloxacin (1 ng*L−1) and sulfamethoxazole (4 ng*L−1) persisted in the river. At the retirement home, in the medical center, even though no tetracycline and sulfamethoxazole were consumed, the highest occurrences of antibiotic resistance were in classes of quinolones (42.0%), sulfonamides (24.0%), tetracyclines (38.0%), and penicillins (38.0%), mainly due to the presenceof multiple antibiotic-resistance genes on class 1 integrons. Along the continuum, the occurrence of E. coli resistant to antibiotics and those carrying class 1 integrons decreased in water samples (p-value <0.001). Interestingly, in the river, only persistent antibiotic compounds (ofloxacin, sulfamethoxazole) were found, but they did not correspond to the major resistances (tetracycline, amoxicillin) of E. coli.
(Environmental Science and Technology. vol. 46, n° 0013-936X, pp. 1859−1868, 28/10/2026)
M2C, UNICAEN, NU, INSU - CNRS, UNIROUEN, NU, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, SCALE, ULH, NU, UNIROUEN, NU, CNRS
La variabilité climatique rapide de la dernière période glaciaire et l’extinction des Néandertaliens
(pp. 107-121, 28/10/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, PACEA, UB, CNRS
Influence of Hydrological Parameters on Organohalogenated Micropollutant (Polybrominated Diphenyl Ethers and Polychlorinated Biphenyls) Behaviour in the Seine (France)
The temporal dynamics of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) were investigated in a heavily urbanized river (Seine River, Paris, France) from November 2009 to May 2010. Pollutant concentrations were in the range of 0.2 to 3.8 ng l(-1) (median 1.1) and 0.4 to 3.6 ng l(-1) (median 1.1) for a tri-deca BDEs and a 7PCBs, respectively. In addition, for both PBDEs and PCBs, the partitioning between the particulate and dissolved phases was investigated. Due to their low water solubility, PBDEs were mainly (> 70%) bound to particles. In contrast, only 54% of a 7PCBs occurred in the particulate phase, and their partitioning was influenced by the degree of chlorination. During the sampling period, PBDE/PCB fluxes were quite similar and ranged from 3 to 128 and from 6 to 125 g day(-1), respectively. The annual mass flow of PBDEs and PCBs was estimated to 10 kg for both. Contrary to PCBs and BDE-209, the temporal evolution of a tri-hepta BDEs was related to particulate organic matter content, which is controlled by river flow variations. This suggests that they exhibit different sources or behavior in the Seine River.
(Archives of Environmental Contamination and Toxicology. vol. 62, n° 0090-4341, pp. 570-578, 28/10/2026)
SISYPHE, UPMC, EPHE, PSL, PSL, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Vegetation dynamics in the Northeastern Mediterranean region during the past 23 000 yr: insights from a new pollen record from the Sea of Marmara
Abstract. High-resolution pollen analysis of core MD01-2430 from the Sea of Marmara (40°47.81' N, 27°43.51' E) allows us to reconstruct the vegetation response to climatic changes during the past 23 cal ka in the Northeastern Mediterranean. Variation in mesic/temperate forest cover indicates major climatic shifts connected to Heinrich Stadial 1, Bölling-Allerød, Younger Dryas and to the onset of the Holocene. Pollen–anthropogenic indicator approach was used to recognize human-induced landscape changes in the Sea of Marmara. The pollen-inferred onset of the Holocene occurs at ca. 11.5 cal ka, indicating that the Northeastern Mediterranean region represents a transitional zone where higher moisture availability supported an earlier forest expansion than the borderlands of the Aegean Sea and Black Sea. Two major forest retreats occurred during the Holocene at ca. 5.5 and 2.1 cal ka. The Holocene forest setbacks are in phase with previously published alkenone-inferred sea-surface temperature decreases in the Sea of Marmara reconstructed from the same core. Our new pollen record testifies the sensitivity of Mediterranean forests to changes in moisture availability, which is driven by changes in high-latitude atmospheric processes (North Atlantic Oscillations and/or Siberian High).
(Climate of the Past. vol. 8, n° 1814-9324, pp. 1941-1956, 28/10/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UMR ISEM, Cirad, IRD, EPHE, PSL, UM, CNRS
Assessing the effect of macrobenthos diversity on the mineralisation of sediment organic matter
(28/10/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LGE, UPD7, IPG Paris, LPG-ANGERS, LPG, UA, UN UFR ST, UN, INSU - CNRS, CNRS, IPGP, INSU - CNRS, UPD7, UR, IPG Paris, CNRS, LOBB, OOB, UPMC, CNRS, UPMC, INSU - CNRS, CNRS, OOB, SU, CNRS, CNRS
Sedimentary processes in the Cap-Ferret canyon (Bay of Biscay, NE Atlantic): from seasonal to century time scales
(28/10/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UCAD, LPG-ANGERS, LPG, UA, UN UFR ST, UN, INSU - CNRS, CNRS, JAMSTEC
Synergie de l’imagerie satellitaire optique et radar pour la cartographie des habitats du Bassin d'Arcachon
L’imagerie satellitaire optique dispose d’un bon potentiel de cartographie des espaces naturels littoraux de par l’emprise spatiale, la haute résolution et le recul temporel qu’offrent les 25 ans d’archives image SPOT. Cet article explore le potentiel des images SAR (Synthetic Aperture Radar) Haute Résolution (HR) pour la cartographie des habitats intertidaux en complément de l’imagerie optique traditionnelle. Dans un premier temps, l’article évalue le potentiel de discrimination des habitats du Bassin d’Arcachon à partir d’une série temporelle constituée de 15 images TerraSAR-X et de 2 images ALOS-PALSAR acquises entre 2007 et 2011. L’étude a permis de caractériser les signatures radar de la couverture sédimentaire intertidale, des herbiers de zostères, des bancs d’huitres et de la végétation du schorre. Les bancs d’huîtres, les structures ostréicoles et le schorre ont des signatures radar très particulières (forte brillance) ce qui permet de les distinguer de la slikke, qu’elle soit végétalisée ou non, et de lever la confusion issue de l’analyse d’une image optique seule. Dans un second temps, l’article développe les résultats issus de la classification des données optiques et radar concaténées sur le secteur de La Hume. Les résultats les plus satisfaisants sont obtenus avec une classification supervisée de Mahalanobis basée sur les 4 bandes SPOT d’une image estivale, la bande XS2 d’une image SPOT d’hiver et une bande radar HH TerraSAR-X. Cette approche cartographique combinant données optiques-radar multi-temporelles permet de lever les principales difficultés ayant motivé cette étude. Des développements sont toutefois encore nécessaires pour parvenir à mieux cartographier les grands ensembles végétaux du schorre et à détecter les biofilms à microphytobenthos ainsi que les dépôts de macro-algues.
(pp. 10, 28/10/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UMR TETIS, Cirad, IRSTEA
Reduction of refractory micropollutants in treated wastewater by advanced tertiary treatments
Some refractory micropollutants remain in treated wastewater after secondary treatments. In order to reduce their concentration in treated water, tertiary treatments can be used such as advanced oxidation processes and activated carbon. The efficiency of granular activated carbon in a long term is not well known and advanced oxidation processes have mostly been studied at laboratory scale. Advanced oxidation processes and granular activated carbon pilots were studied in two different wastewater treatment plants in order to determine their efficiency on numerous micropollutants. Both processes were efficient (>90%) on beta blockers and other drugs. The removal of alkylphenols was not complete with UV and hydrogen peroxide. Activated carbon was still efficient after six months functioning 24/24.
(pp. 4, 28/10/2026)
IRSTEA, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UR MALY, IRSTEA