Modelling analysis of tidal bore formation in convergent estuaries
(23/06/2026)
CARDAMOM, IMB, UB, Bordeaux INP, CNRS, Inria, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
First isolation of a rhabdovirus from perch Perca fluviatilis in Switzerland
Perca fluviatilis is a fish species of increasing interest to the Swiss fish farming industry. In recent years, recirculation systems have been specifically set up to increase production. In one of these farms, abnormal spiral swimming associated with elevated mortalities occurred in repeated batches of imported perch shortly after stocking on several occasions. No bacterial or parasitic etiology was detected, but a virus grown in bluegill fry (BF-2) cells was identified as perch rhabdovirus. Subsequent investigations of other samples suggested a viral tropism for the central nervous system (CNS). Phylogenetic analysis of the partial N and entire G gene sequences positioned this isolate in genogroup C of the species Perch rhabdovirus, with high nucleotide and amino acid (aa) sequence identities with the DK5533 strain isolated in Denmark in 1989. Comparative studies using other closely related isolates allowed the distinction of 2 serological patterns among perch rhabdoviruses and the identification of a proline substitution by a serine in position 147 of the glycoprotein potentially involved in antigenic differentiation. Even if perch imported onto the farm tested negative by virus isolation prior to transport, they may have been the origin of this outbreak since CNS tissue was not included in the samples that were analyzed. Another possibility might be a sub-clinical infection with a viral load in resident fish too low to be detected. This study reports the first isolation of a perch rhabdovirus in Switzerland, and emphasizes the necessity of optimizing diagnostic tools that facilitate better control of the risks associated with fish translocation.
(Diseases of Aquatic Organisms. vol. 116, n° 0177-5103, pp. 93-101, 23/06/2026)
UNIBE, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, ANSES
Rôle des interactions plante-plante dans la réponse des forêts au changement climatique : l’exemple des forêts de chêne sessile et de hêtre dans les Pyrénées Occidentales
Les recherches concernant l’impact du changement climatique sur les forêts, telles que les modèles d’enveloppes climatiques et les modèles phénologiques, ignorent les interactions biotiques. Notre objectif est l’étude du rôle médiateur des interactions chêne-hêtre dans leur réponse au changement climatique dans les Pyrénées Occidentales. Des études préliminaires suggèrent que des différences importantes de sensibilité phénologique à la température entre ces espèces pourraient expliquer leur répartition altitudinale actuelle et l’évolution de leur balance compétitive avec le changement climatique. Nous présentons ici les résultats d’une expérimentation réalisée in situ et ayant pour but de quantifier les variations d’interactions entre des plantules de ces deux espèces et les arbres adultes le long d’un gradient altitudinal. Les résultats pour la survie des plantules montrent une augmentation importante de la compétition en altitude pour le chêne seulement. C’est le manque de chaleur à l’ombre du hêtre à haute altitude qui limite actuellement la longueur de la saison de végétation du chêne et sa progression en altitude. Le réchauffement climatique devrait diminuer la compétition subie par le chêne relativement au hêtre de par sa plus grande sensibilité phénologique à la température et ainsi exacerber les effets du changement climatique sur la migration altitudinale de ces deux espèces.
(Innovations Agronomiques. vol. 47, n° 1958-5853, pp. 97-108, 23/06/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UNINE, BioGeCo, INRA, UB
The ocean sampling day consortium
Ocean Sampling Day was initiated by the EU-funded Micro B3 (Marine Microbial Biodiversity, Bioinformatics, Biotechnology) project to obtain a snapshot of the marine microbial biodiversity and function of the world’s oceans. It is a simultaneous global mega-sequencing campaign aiming to generate the largest standardized microbial data set in a single day. This will be achievable only through the coordinated efforts of an Ocean Sampling Day Consortium, supportive partnerships and networks between sites. This commentary outlines the establishment, function and aims of the Consortium and describes our vision for a sustainable study of marine microbial communities and their embedded functional traits.
(GigaScience. vol. 4, pp. 27, 23/06/2026)
NERC, AD2M, SBR, UPMC, CNRS, UPMC, CNRS, IOLR, AWI, HCMR, DTU, SBR, UPMC, CNRS, UCC, IRB, OFFIS, ULISBOA, ISMAR, CNR, GEOMAR, SYKE, NOAA, UiB, CIIMAR, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, CINVESTAV, USC, LOMIC, OOB, UPMC, CNRS, UPMC, CNRS, UDELAR, CSIRO, SARDI, VLIZ, CEFAS, UAlg, LOV, OOVM, UPMC, INSU - CNRS, CNRS, UPMC, INSU - CNRS, CNRS, UTAS, CRIOBE, UPVD, EPHE, PSL, CNRS, UPV / EHU, UM5, USMBA, UAE, BAS, EMBL-EBI, EMBL, UBO EPE, DEÜ, Unipd, NTU, IPMA, IGS, AMU, CNRS, OGS, RUSL, USM, UiO, ICM, CSIC, MU, SZN, UNIVPM, BAS, NERC, UAF, MBL, ANL, UC Berkeley, UC
Seasonal changes in stable carbon and nitrogen isotope compositions of bat guano (Guadeloupe)
Stable isotope compositions of fossil bat guano have recently been developed as a proxy for reconstructing terrestrial paleoenvironments. However, our understanding of exactly how accurately these isotope compositions reflect seasonal variations remains limited. Here, we present a study of modern guano of phytophagous bats collected monthly over a one-year period at two roosting sites in Guadeloupe. The aim is to assess the degree to which seasonal climate and environmental variations are reflected in carbon and nitrogen isotope compositions from bat guano, as well as to evaluate the potential use of guano from phytophagous bats as a paleoenvironmental record. Our results show that stable isotope compositions vary locally, suggesting that guano of phytophagous bats accurately records local environmental conditions. Additionally, stable isotope compositions reflect seasonal variations influencing bat diet that lead to modifications of up to 2‰ of the carbon isotope compositions from feces. However, these variations are not correlated solely with climate variables as there is no straightforward relationship between climate, vegetation and bat diet over a one-year period. Moreover, these seasonal variations drive one of the bat colonies to occasionally consume insects, which can be traced as a seasonal shift in %N (up to 4.5%) and carbon isotope compositions (up to 5.6‰). Seasonal changes in isotope compositions are still lower than expected variations from fossil feces, confirming the potential use of feces from phytophagous bats as a reliable paleoenvironmental proxy.
(Palaeogeography, Palaeoclimatology, Palaeoecology. vol. 440, n° 0031-0182, pp. 524-532, 23/06/2026)
PACEA, UB, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Occurrence and Removal of Organic Micropollutants in Landfill Leachates Treated by Electrochemical Advanced Oxidation Processes
In recent years, electrochemical advanced oxidation processes have been shown to be an effective alternative for the removal of refractory organic compounds from water. This study is focused on the effective removal of recalcitrant organic matter (micropollutants, humic substances, etc.) present in municipal solid waste landfill leachates. A mixture of eight landfill leachates has been studied by the electro-Fenton process using a Pt or boron-doped diamond (BDD) anode and a carbon felt cathode or by the anodic oxidation process with a BDD anode. These processes exhibit great oxidation ability due to the in situ production of hydroxyl radicals (OH), a highly powerful oxidizing species. Both electrochemical processes were shown to be efficient in the removal of dissolved total organic carbon (TOC) from landfill leachates. Regarding the electro-Fenton process, the replacement of the classical anode Pt by the anode BDD allows better performance in terms of dissolved TOC removal. The occurrence and removal yield of 19 polycyclic aromatic hydrocarbons, 15 volatile organic compounds, 7 alkylphenols, 7 polychlorobiphenyls, 5 organochlorine pesticides, and 2 polybrominated diphenyl ethers in landfill leachate were also investigated. Both electrochemical processes allow one to reach a quasicomplete removal (about 98%) of these organic micropollutants.
(Environmental Science and Technology. vol. 49, n° 0013-936X, pp. 12187-12196, 23/06/2026)
UPEM, IRSTEA, UR HBAN, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Photolysis of natural β-triketonic herbicides in water.
The fate of four natural β-triketones (leptospermone, isoleptospermone, grandiflorone and flavesone, pKa = 4.0–4.5) in aqueous solution, in the dark and upon simulated solar light irradiation was investigated. In anionic form, β-triketones undergo slow dark oxidation and photolysis with polychromatic quantum yields varying from 1.2 × 10−4 to 3.7 × 10−4. Leptospermone and grandiflorone are the most photolabile compounds. In molecular form, β-triketones are rather volatile. Polychromatic quantum yields between 1.2 × 10−3 and 1.8 × 10−3 could be measured for leptospermone and grandiflorone. They are 3–5 times higher than for the anionic forms. Photooxidation on the carbon atom bearing the acidic hydrogen atom is the main oxidation reaction, common to all the β-triketones whatever their ionization state. However, leptospermone shows a special photoreactivity. In molecular form, it mainly undergoes photoisomerization. Based on this work, the half-lives of β-triketones in surface waters should be comprised between 7 and 23 days.
(Water Research. vol. 78, n° 0043-1354, pp. 28-36, 23/06/2026)
ICCF, UBP, SIGMA Clermont, INC-CNRS, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Gonadal transcriptome analysis of wild contaminated female European eels during artificial gonad maturation
Since the early 1980s, the population of European eels (Anguilla anguilla) has dramatically declined. Nowadays, the European eel is listed on the red list of threatened species (IUCN Red List) and is considered as critically endangered of extinction. Pollution is one of the putative causes for the collapse of this species. Among their possible effects, contaminants gradually accumulated in eels during their somatic growth phase (yellow eel stage) would be remobilized during their reproductive migration leading to potential toxic events in gonads. The aim of this study was to investigate the effects of organic and inorganic contaminants on the gonad development of wild female silver eels. Female silver eels from two sites with differing contamination levels were artificially matured. Transcriptomic analyses by means of a 1000 candidate gene cDNA microarray were performed on gonads after 11 weeks of maturation to get insight into the mechanisms of toxicity of contaminants. The transcription levels of several genes, that were associated to the gonadosomatic index (GSI), were involved in mitotic cell division but also in gametogenesis. Genes associated to contaminants were mainly involved in the mechanisms of protection against oxidative stress, in DNA repair, in the purinergic signaling pathway and in steroidogenesis, suggesting an impairment of gonad development in eels from the polluted site. This was in agreement with the fact that eels from the reference site showed a higher gonad growth in comparison to contaminated fish.
(Chemosphere. vol. 139, n° 0045-6535, pp. 303--309, 23/06/2026)
BOREA, UNICAEN, NU, MNHN, IRD, SU, CNRS, UA, IBIS, ULaval, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, µVIS X-ray Imaging Centre, UR EABX, IRSTEA, INRS, LPTC, UB, CNRS, ISM, UB, INC-CNRS, CNRS
Impact de deux antifouling, l’irgarol 1051 et le diuron sur la physiologie de deux souches de la micro-algue marine Tetraselmis suecica
L’irgarol 1051 (I) et le diuron (D) sont deux biocides couramment utilisés dans les peintures antifouling et les antimousses. Ils ciblent directement le photosystème II en inhibant le transfert d'électrons entre les quinones A et B. De par ce mode d’action, de nombreuses cibles indirectes peuvent être affectées en cas de contamination environnementale. Les effets de ces deux composés ont été étudiés, seuls et en mélange, sur deux souches d’une espèce de phytoplancton marin, Tetraselmis suecica : une souche "sauvage" (CCMP 904) (TS) et une souche résistante au diuron (TM) obtenue récemment au Laboratoire d’Ecotoxicologie (Stachowski-Haberkorn et al., 2013). Les effets des molécules ont été étudiés, chez les deux souches, sur la croissance, le rendement photosynthétique, la présence d'espèces réactives de l'oxygène (EROs, par cytométrie en flux) et le contenu relatif en lipides intracellulaires (cytométrie en flux) après une exposition de 6 jours. Les conditions d’exposition étaient les suivantes : I0.05, I0.1 et I0.5 μg.L-1 ; D0.5, D1 et D5 μg.L-1 ; quatre mélanges (en μg.L-1) MixA : D5 + I0.5 ; MixB : D5 + I0.1 ; MixC : D1 + I0.5 ; MixD : D1 + I0.1. En parallèle, le séquençage du gène psbA codant pour la protéine D1 du photosystème II (cible du diuron) a été entrepris sur les deux souches afin de déterminer l’origine de la résistance à la molécule chez la souche TM. Les résultats obtenus ont montré que le diuron avait induit des effets significatifs sur l’ensemble des paramètres étudiés de la souche TS à la concentration de 5 μg.L-1 : augmentation de 125% (± 2.3%) du temps de doublement, augmentation de 43% (± 1.8%) de la fluorescence relative à la présence d’EROs, diminution de 25% (± 1.8%) du rendement photosynthétique et de 38% (± 1.9%) du contenu lipidique relatif. L’irgarol à 0,5 μg.L-1, a également entraîné des effets significatifs sur l’ensemble des paramètres physiologiques : +19% (± 2%) sur le temps de doublement, +45% (± 4.6%) sur la fluorescence relative à la présence d’EROs, -2% (± 0.6%) sur l’efficacité de photosynthèse et -21% (± 1.3%) sur le contenu lipidique relatif. Suite à l’exposition de la souche aux quatre mélanges, les résultats ont montré des effets cumulés et progressifs (MixA> MixB> MixC> MixD) des molécules sur l’ensemble des paramètres. Pour la souche résistante au diuron, le séquençage de l’ARNm codant pour la protéine D1 a montré une mutation de G en A dans le domaine de liaison de la quinone à la position 661 de la séquence cds. Cette mutation correspond à un changement de la valine en isoleucine en position 221 dans la séquence d'acides aminés de la protéine. Cette mutation a permis à la souche de résister au diuron (aucun effet significatif enregistré quelle que soit la concentration d’exposition). Cependant, cette mutation n’a pas permis de résister à un herbicide au mode d’action similaire puisque l’irgarol à la concentration 0.5 μg.L-1 a engendré des effets délétères sur chacun des paramètres physiologiques : +19% (± 3.4%) sur le temps de doublement, +20% (± 5%) sur la fluorescence relative à la présence d’EROs, -8% (± 0.7%) sur l’efficacité de photosynthèse et -15% (± 2.8%) sur le contenu lipidique relatif. D’autre part, les résultats des expositions réalisées avec les mélanges ont montré des effets synergiques entre les deux molécules bien que le diuron seul n’ait pas eu d’effet (MixA> MixC> MixB> MixD). Ainsi, cette étude démontre la toxicité élevée de ces deux biocides pour l’espèce Tetraselmis suecica. Elle démontre également que la mutation mise en évidence, permettant une résistance au diuron, ne permet pas nécessairement une résistance à un autre inhibiteur du photosystème II. Elle souligne donc la nécessité (i) de considérer les mélanges dans l’évaluation de la toxicité des molécules et (ii) de surveiller le devenir dans l'environnement de ces deux composés encore autorisés dans de nombreux pays dont des pays européens (irgarol).
(pp. 34, 23/06/2026)
UR EABX, IRSTEA, IFREMER, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UB
Is the toxicity of pesticide mixtures on river biofilm accounted for solely by the major compounds identified?
Pesticides are present as a cocktail of compounds at low concentrations in water bodies. Nevertheless, studies assessing the toxic effects of pesticide mixtures at realistic environmental concentrations are still scarce. Polar Organic Chemical Integrative Sampler (POCIS) allows the concentration of several organic chemicals from large volumes of natural water [1]. This high pre-concentration of compounds makes POCIS a powerful tool to assess extract toxicity via biological testing and therefore to study the impact of realistic mixtures . PE can be used as a black box with the advantages of dealing with mixtures “as they came”; this approach gives an estimation of an integrative measure of the toxic potential of a group of compounds including unknown toxicants without using an a priori approach. With this protocol, the global toxicity of the extract is assessed although the compounds responsible for the observed toxicity are not identified. The present study aimed to characterize the effects of long-term and low-dose exposure to POCIS extracts in a context of contamination by cereal crops on a natural biofilm community and to evaluate whether the effects observed due to exposure to PE were explained by the major compounds identified in the extracts [2].
(pp. 2, 23/06/2026)
UR EABX, IRSTEA, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS