PAHs and fish-exposure monitoring and adverse effects-from molecular to individual level
Polycyclic aromatic hydrocarbons (PAHs) are a diverse family of more than one hundred compounds, containing at least two aromatic rings. In addition to parent compounds, the PAH family also includes substituted derivatives, bearing one or several alkyl groups, sulfur, or oxygen. In the environment, PAHs are ubiquitous and present as very complex mixtures. They can also be associated with metallic and/or other organic compounds. The composition of PAH mixtures depends on their origin. There are two major types of such PAH mixtures, petrogenic and pyrogenic, which enter the environment through different routes. Petrogenic mixtures originate from oils, including natural oil seeps. They enter the aquatic environment due to harbor activity or soil runoff or as a consequence of oil spills. Pyrolytic mixtures result from the incomplete combustion of organic matter, including fossil fuel, entering aquatic environments through deposits of atmospheric emissions directly into water or soil, followed by soil erosion and runoff. Directly linked to human activity, the release of PAHs into the environment has increased over the last few decades. As an example, the amount of PAHs released into the atmosphere has dramatically increased from under 50,000 tons in 1987 (Eisler 1987) to over 500,000 tons in 2004 (Zhang and Tao 2009)
(Environmental Science and Pollution Research. vol. 21, n° 0944-1344, pp. 13685-13688, 23/04/2026)
LPGP, INRA, Biosit : Biologie - Santé - Innovation Technologique, BE, IFREMER, UB, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Flash rip dynamics on a high-energy low-tide-terraced beach (Grand Popo, Benin, West Africa)
Rip currents are wave-driven intense seaward-flowing jets of water that are important to both beach morphodynamics and the overall ecosystem. Rip currents are also the leading deadly hazard to recreational beach users worldwide. More specifically, the African region is reported to have the highest rates of drowning in the world, yet both the occurrence and the type of rips developing along the African beaches are unknown. In February 2013, a 12-day field experiment was performed at the high-energy low-tide-terraced sandy beach of Grand Popo beach (Benin, West Africa). Human drifter data and video imagery are combined to address wave-driven circulation and rip current activity. Results show two prevailing rip current types. (1) Low-energy (~0.2-0.4 m/s) swash rips, with short life-spans of about 1 minute, extend about 5-10 m offshore and occur preferably at mid to high tide at fixed locations in the center of beach cusps. (2) Higher-energy (0.2 - 0.8 m/s) surfzone flash rips become active with the onset of intense wave breaking across the low-tide terrace. They tend to migrate downdrift with alonger time-span of about 2-5 minutes. The relatively weak longshore current (0.2 - 0.55 m/s) measured during the experiment suggests that flash rips were driven by vorticity generated by wave breaking rather than shear instabilities of the longshore current. Swash rips and flash rips are common at Grand Popo and often co-exist. We propose a conceptual model of both flash and swash rip activity on this stretch of the West African coast.
(Journal of Coastal Research. vol. SI 70, n° 0749-0208, pp. 633-638, 23/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, ECOLA, LEGOS, IRD, UT3, Comue de Toulouse, INSU - CNRS, CNES, CNRS, CEREGE, IRD, INRA, AMU, CdF (institution), INSU - CNRS, CNRS, IRD [France-Ouest]
Living (stained) deep-sea Foraminifera off Hachinohe (NE Japan, Western Pacific): environmental interplay in oxygen-depleted ecosystems
Live (Rose-Bengal stained) deep-sea foraminiferal faunas have been studied at five stations between 500–2000-m depth along the NE Japanese margin (western Pacific) to understand how complex environmental conditions (e.g., oxygen depletion, organic matter) control their structure (i.e., diversity, standing stocks, and microhabitats). All stations are characterized by silty sediments with no evidence of recent physical disturbances. The three stations located between 760–1250 m are bathed by dysoxic bottom waters (<45 μmol/L). Although high organic-carbon contents are recorded at all stations (>2.2% DW), only the oxygen-depleted sites are characterized by higher concentrations of sugars, lipids, and enzymatically hydrolysable amino acids (EHAA). Sedimentary contents in chlorophyllic pigments decrease with water depth without any major change in their freshness (i.e., [Chl a/(Chl a + Pheo a)] ratios). Both Uvigerina akitaensis and Bolivina spissa are restricted to the stations bathed by dysoxic waters, proving their oxygen-depletion tolerance. In such conditions, both phytophagous taxa are obviously able to take advantage of labile organic compounds (e.g., lipids and EHAA) contained in phytodetritus. Nonionella stella and Rutherfordoides cornuta survive in oxygen-depleted environments probably via alternative metabolic pathways (e.g., denitrification ability) and a large flexibility in trophic requirements. At stations where oxygen availability is higher (i.e., >70 μmol/L in bottom water) and where bioavailable organic compounds are slightly less abundant, diversity indices remain low, and more competitive species (e.g., Uvigerina curticosta, U. cf. U. graciliformis, Nonionella globosa, Nonionellina labradorica, and Elphidium batialis) are dominant.
(Journal of Foraminiferal Research. vol. 44, n° 0096-1191, pp. p. 281-299, 23/04/2026)
GM, IFREMER, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, JAMSTEC, CEFREM, UPVD, INSU - CNRS, CNRS, CEREGE, IRD, INRA, AMU, CdF (institution), INSU - CNRS, CNRS, NIOZ
Multi-agent modelling of the trajectory of the LBK Neolithic: a study in progress
(23/04/2026)
EVS, ENS de Lyon, Mines Saint-Étienne MSE, IMT, UL2, UJML, INSA Lyon, INSA, UJM, ENTPE, ENSAL, CNRS, ALLHiS, UJM, ArScAn, UP1, UP8, UPN, MCC, CNRS, UMR LISAH, IRD, INRA, Montpellier SupAgro, Montpellier SupAgro, BioArch, MNHN, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, Inrap, CEPAM, UNS, CNRS, REEDS, UVSQ
Geochemical composition of Trondheimsfjord surface sediments: Sources and spatial variability of marine and terrigenous components
High sedimentation rates in fjords provide excellent possibilities for high resolution sedimentary and geochemical records over the Holocene. As a baseline for an improved interpretation of geochemical data from fjord sediment cores, this study aims to investigate the inorganic/organic geochemistry of surface sediments and to identify geochemical proxies for terrestrial input and river discharge in the Trondheimsfjord, central Norway. Sixty evenly distributed surface sediment samples were analysed for their elemental composition, total organic carbon (C org), nitrogen (N org) and organic carbon stable isotopes (δ 13 C org), bulk mineral composition and grain size distribution. Our results indicate carbonate marine productivity to be the main CaCO 3 source. Also, a strong decreasing gradient of marine-derived organic matter from the entrance towards the fjord inner part is consistent with modern primary production data. We show that the origin of the organic matter as well as the distribution of CaCO 3 in Trondheimsfjord sediments can be used as a proxy for the variable inflow of Atlantic water and changes in river runoff. Furthermore, the comparison of grain size independent Al-based trace element ratios with geochemical analysis from terrigenous sediments and bedrocks provides evidence that the distribution of K/Al, Ni/Al and K/Ni in the fjord sediments reflect regional sources of K and Ni in the northern and southern drainage basin of the Trondheimsfjord. Applying these findings to temporally well-constrained sediment records will provide important insights into both the palaeoenvironmental changes of the hinterland and the palaeoceanographic modifications in the Norwegian Sea as response to rapid climate changes and associated feedback mechanisms.
(Continental Shelf Research. vol. 88, n° 0278-4343, pp. 61-71, 23/04/2026)
UiT, NGU, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Effets de la qualité des sédiments de frayère sur le développement embryo-larvaire de l'esturgeon européen (Acipenser sturio)
Les embryons et larves d'esturgeon européen ont été exposés aux substrats de 2 frayères situées sur la Dordogne et la Garonne. Les individus exposés au substrat de La Réole (Garonne) présentent une augmentation du taux de malformation, une altération des capacités physiologique et natatoire.
(pp. 15, 23/04/2026)
UR EABX, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Echantillonneurs passifs : évaluation de l’exposition des biofilms aux mélanges de pesticides, et du risque écotoxique dans les cours d’eau
La contamination généralisée des cours d’eau par les pesticides, généralement en mélanges et à concentrations relativement faibles, requiert la prise en compte dans le diagnostic de la complexité de l’exposition. Le développement récent de l’échantillonnage passif des contaminants a permis d’une part de mieux considérer la diversité des contaminants présents dans l’environnement, et d’abaisser leurs limites de détection, fournissant ainsi un panorama plus exhaustif de la contamination réelle. Le biofilm est une communauté complexe, composée de microalgues, de bactéries, de champignons, de protozoaires, etc. enchâssés dans une matrice polysaccharidique. Son utilisation en écotoxicologie revêt un haut degré de pertinence environnementale, comparé aux espèces modèles utilisées traditionnellement. Elle permet de mieux comprendre et prédire les impacts réels de contaminants pour l’écosystème, bien mieux que l’extrapolation de résultats déconnectés de la complexité des conditions de milieu (diversité des organismes, et de leurs relations). Le modèle biofilm a ainsi été utilisé avec succès dans de nombreuses études écotoxicologiques au laboratoire, utilisant des contaminants seuls ou en combinaisons simples (binaires, ternaires) de substances. Cependant, la qualification du risque écotoxique associé aux mélanges de contaminants est difficilement envisageable par ce biais, la multiplicité des mixtures possibles (en termes de composition et de concentrations) empêchant de tester toutes les combinaisons susceptibles d’être rencontrées in situ. Nous proposons ici de présenter les avancées récentes permises par le couplage entre échantillonnage passif et écotoxicologie, pour la mesure du potentiel toxique dans les milieux aquatique, et pour la mise en ½uvre d’expérimentations plus réalistes environnementalement.
(pp. 2, 23/04/2026)
UR EABX, IRSTEA, UR MALY, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Persistent Organic Pollutants in a marine bivalve on the Marennes-Oléron Bay and the Gironde Estuary (French Atlantic coast) -Part 1: Bioaccumulation
The aim of this study was to determine 1) the relevance of using the Pacific oyster Crassostrea gigas as a sentinel organism, at a juvenile stage, for polycyclic aromatic hydrocarbon (PAH) and persistent organic pollutant (polychlorobiphenyls, PCBs, polybromodimethylethers, PBDEs, and organochlorine pesticides, OCPs) contamination, 2) the potential levels of chemical organic contamination in the Marennes-Oleron Bay, and their potential sources 3) the potential influence of physiological or environmental factors on contaminant body burdens in oysters. To this end, juvenile oysters purchased from a oyster hatchery were transplanted to a reference site, in Bouin, and to different transplantation sites in the Marennes-Oléron Bay, the first oyster production area in France, and in the Gironde Estuary, the biggest estuary in Occidental Europe. Transplantations were done during summer and winter. Whole oyster soft tissues from each site were analyzed for PAHs, PCBs, PBDEs and OCPs. Results obtained with a transplantation period of 3 months suggest that the C. gigas, at the juvenile stage, is a relevant sentinel organism for short-term contamination for these contaminants. In addition, no significant effects of physiological factors on contaminant body burdens were observed. A principal component analysis performed with chemical body burdens allowed them to be separated into three groups: 1) the reference site, 2) Les Palles (LP) and Boyard (BOY) in winter and 3) all the other sites. The group of LP and BOY was clearly defined by the levels of PAHs and OCPs, suggesting higher levels of contamination of these chemical compounds on these sites, potentially due to local contamination sources. In addition, no relevant effects of physiological or environmental factors on contaminant body burdens were observed. Results suggest also a predominance of contaminants related to agricultural activities along the Marennes-Oléron Bay, and therefore, further studies on the presence of pesticides in this region should be considered.
(Science of the Total Environment. vol. 514, n° 0048-9697, pp. 500-510, 23/04/2026)
PUJ, LIENSs, INSU - CNRS, ULR, CNRS, UB, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Vulnérabilité et résilience des estuaires à la contamination en antibiotiques et en bactéries antibiorésistantes
(pp. 105-130, 23/04/2026)
M2C, UNICAEN, NU, INSU - CNRS, UNIROUEN, NU, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UNICAEN, NU, AP-HP, AP-HP, UPD7, ECOBIO, UR, INEE-CNRS, CNRS, CNRS, IAME (UMR_S_1137 / U1137), UP13, UPD7, USPC, INSERM
Competition, facilitation and environmental severity shape the relationship between local and regional species richness in plant communities
Understanding the relative contribution of local and regional processes to local species richness is an important ecological question and a subject of controversy between macroecologists and community ecologists. We test the hypothesis that the contribution of local and regional processes is dependent on environmental conditions and that the eff ect of regional processes should be the highest in communities from intermediate positions along environmental severity gradients due to the importance of facilitation. We used the recently developed log-ratio method to analyze the relationship between local species richness (LSR) and regional species richness (RSR) for 13 plant communities from 4 habitat types of France (coastal sand dunes, oceanic heathlands, alpine grasslands, lowland calcareous grasslands). Each habitat type wassplit in 3 – 4 communities using multivariate analyses to identify the relative importance of stress, disturbance, competition, and facilitation functioning within the 13 communities. We found that the LSR/RSR relationship was highly dependent on environmental conditions with saturated communities occurring more frequently than unsaturated communities highlighting the relative importance of local drivers on species richness. We argued that competition was most likely the main source of community saturation whilst facilitation likely contributed to enhancing the importance of the regional species pool for all habitat types. However, the eff ect of facilitation might be stronger in the disturbed than in the stressed systems because unsaturated curves were only observed in the former conditions. In extreme conditions of disturbance LSR was only controlled by the intensity of disturbance. Th is eff ect was not observed in extreme stress conditions. Our study provides support for the emerging balance theory that both local and regional processes are important in nature with their relative contribution depending on environmental conditions. Additionally, this synthesis strongly suggests that facilitation contributes to an important process – the influence of regional species pool on local species richness.
(Ecography. vol. 37, pp. 1-11, 23/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LECA, UJF, USMB [Université de Savoie] [Université de Chambéry], CNRS, SAJF, UJF, CNRS, ECOBIO, UR, INEE-CNRS, CNRS, CNRS, ONF, IEU, UZH