Fish gut and skin microbiota dysbiosis induced by exposure to commercial sunscreen formulations
UV filters (organic or mineral) present in sunscreen products are emerging contaminants of coastal aquatic environments. There is an urgent need to understand marine organisms responses to these compounds. In this study, we investigated the effect of exposure to dilutions of commercial sunscreen formulations on bacterial communities of mullet (Chelon sp.). The gut and skin mucus microbial communities were characterized using a metabarcoding approach targeting the 16S rRNA gene. Our results revealed that mullets had its own bacterial communities that differ from their surrounding habitats and specific to tissue. The dilutions of commercial sunscreens modified the relative abundance of Actinobacteroita, Bacteriodota and Proteobacteria for both gut and skin microbiota. They also allowed to bacteria affiliated to Mycobacterium, Nocardia and Tenacibaculum genera, known to house pathogenic species, to colonize the epithelium which may have implications for fish host health.
(Aquatic Toxicology. vol. 266, n° 0166-445X, pp. 106799, 23/02/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LIENSs, INSU - CNRS, ULR, CNRS, LEMAR, IRD, IFREMER, UBO EPE, CNRS
Caractérisation de l’hydrodynamisme des plages et des petits fonds du littoral au sud de l’estuaire de la Gironde à partir de mesures in situ
Le littoral Nord-Médoc, situé au sud de l'estuaire de la Gironde, est soumis à des conditions hydrodynamiques complexes, résultant de l'interaction entre des houles énergétiques et des courants tidaux intenses au sein d'un environnement alternant platiers rocheux, bancs de sables et chenaux de marée. La résultante est un gradient hydrodynamique latitudinal influençant fortement l'évolution morphologique de la côte. Une campagne de mesures de deux semaines a été menée en automne 2022 pour caractériser pour le première fois in situ cette dynamique. Les données ont été collectées le long de trois profils cross-shore s'étendant des petits fonds à l'estran. Les résultats issus de courantomètres profileurs (i.e. ADCP, Aquadopp) et de capteurs de pression ont pu montrer la prédominance des courants tidaux sur l'ensemble du site d'étude (i.e. courant longitudinaux), avec une intensification notable du nord vers le sud. Cette tendance se caractérise par une dominance des courants de flot au Nord, tandis que le jusant domine au sud et au centre du domaine d'étude. Les observations sur les vagues et les courants, en plus d'apporter des éléments de compréhension inédits sur les dynamiques hydrosédimentaires, constituent une base de données indispensable à la validation des modèles de circulation et les prévisions d'évolution du trait de côte dans cette région soumise à l'érosion chronique
(pp. 215-223, 23/02/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, BRGM, LIENSs, INSU - CNRS, ULR, CNRS
Environmental controls on lifeguard-estimated surf-zone hazards, beach crowds, and resulting life risk at a high-energy sandy beach in southwest France
Understanding and predicting surf zone risks is of paramount importance to prevent drowning incidents and severe spine injuries on beaches globally. This study holistically addressed life risk at La Lette Blanche beach, southwest France, during the lifeguard-patrolled summer period (July-August) 2022, where intense rip currents and shore-break waves co-exist at different times and locations along the beach. Beach crowds and the levels of rip current and shore-break wave hazards were estimated hourly by lifeguards during patrolling hours. Wave, tide and weather conditions were also continuously recorded, providing comprehensive insights into the primary environmental controls on surf zone hazards and beach attendance. Results show that the daily average rip current hazard increases with large, long-period and near shore-normal waves, while the shore-break wave hazard is increased for long-period, near shore-normal waves and large tide ranges. Beachgoer crowd numbers increase on warm, sunny and light wind days although a severe heat wave occurring in July 2022 significantly decreased daily average beach crowd and deeply affected beach use. Days characterized by strong hazards and large beach attendance were associated with the largest amount of lifeguard rescues and drowning incidents, although correlations decreased by the end of the summer. This is hypothesized 1 to be the signature of evolving lifeguard strategies (e.g. preferred locations of the supervised bathing zone, prevention measures) as they progressively increase their understanding of the surf zone hazards variability in both time and space at their beach as a function of tidal stage and incident wave conditions. Warm, sunny and light-wind sunny days (maximizing beach crowds), with large, longperiod shore-normally incident waves and large tide range (maximizing surf zone hazards) were the most risky days, with shore-break waves and rip current hazards notably peaking at different times of the day. This study shows that lifeguards can be a valuable source of data to improve understanding of the environmental controls on beach crowd, surf zone hazards and life risk at the beach, which provides critical information to the development of holistic beach risk predictors.
(Natural Hazards. vol. 120, n° 0921-030X, pp. 1557–1576, 23/02/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UR ETTIS, INRAE
Concurrent Asian monsoon strengthening and early modern human dispersal to East Asia during the last interglacial
The relationship between initial Homo sapiens dispersal from Africa to East Asia and the orbitally paced evolution of the Asian summer monsoon (ASM)—currently the largest monsoon system—remains underexplored due to lack of coordinated synthesis of both Asian paleoanthropological and paleoclimatic data. Here, we investigate orbital-scale ASM dynamics during the last 280 thousand years (kyr) and their likely influences on early H. sapiens dispersal to East Asia, through a unique integration of i) new centennial-resolution ASM records from the Chinese Loess Plateau, ii) model-based East Asian hydroclimatic reconstructions, iii) paleoanthropological data compilations, and iv) global H. sapiens habitat suitability simulations. Our combined proxy- and model-based reconstructions suggest that ASM precipitation responded to a combination of Northern Hemisphere ice volume, greenhouse gas, and regional summer insolation forcing, with cooccurring primary orbital cycles of ~100-kyr, 41-kyr, and ~20-kyr. Between ~125 and 70 kyr ago, summer monsoon rains and temperatures increased in vast areas across Asia. This episode coincides with the earliest H. sapiens fossil occurrence at multiple localities in East Asia. Following the transcontinental increase in simulated habitat suitability, we suggest that ASM strengthening together with Southeast African climate deterioration may have promoted the initial H. sapiens dispersal from their African homeland to remote East Asia during the last interglacial.
(Proceedings of the National Academy of Sciences of the United States of America. vol. 121, n° 0027-8424, pp. e2308994121, 23/02/2026)
IEE, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, CUG
Observations of Tide- and Wave-Driven Groundwater Dynamics in Meso-Tidal Sandy Beach
This study focuses on the non-hydrostatic groundwater dynamics of a meso-tidal sandy beach under the influence of tides and waves. A field campaign was conducted at Lacanau Beach, France, during four consecutive tide cycles in March 2022. Groundwater dynamics was monitored based on a network of buried pressure sensors. The data analysis revealed the combined influences of waves and tides on the groundwater circulation. Tidal-scale groundwater flows are predominantly seaward, primarily controlled by the head gradient resulting from a high coastal aquifer. A circulation cell develops under the swash zone and moves across the beachface following the tidal oscillations. On a daily scale per alongshore and vertical units, the observed flow is 2.5 m$^3$ .m$^{-2}$ .day$^{-1}$, i.e., 912.5 m$^3$.m$^{-2}$.year$^{-1}$. Extrapolating the present dataset, it may be expected that combined events, such as drought-induced aquifer depletion with high tides, could lead to beach-scale gradient reversal, potentially causing salinisation of the continental aquifer.
(Water. vol. 16, n° 2073-4441, 23/02/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, MIO, IRD, AMU, INSU - CNRS, UTLN, CNRS, SIAME, UPPA
Millennial‐Scale Climate Variability Potentially Shaped the Early Interglacial Optimum in Southern Europe
The seasonal and latitudinal distribution of insolation is considered the main factor controlling the magnitude and timing of interglacial periods. However, despite small differences in insolation forcing, vegetation and hydrology in southern Europe during past interglacials are variable and the gradual change in insolation cannot explain the observed short‐lived forest optimum. Here we focus on vegetation and hydroclimatic changes at orbital‐ and suborbital‐scales in southwestern Europe during two past warm interglacial periods with reduced ice‐sheets, namely Marine Isotope Stages (MIS) 9e and 5e. We provide new pollen and sea surface temperatures records for MIS 9e from IODP Site U1385. This pollen record shows a forest expansion in southern Iberia over a 14 ky interval, bracketed by the millennial‐scale cooling events of Termination IV and MIS 9d. Between 334.5 and 332.5 ka, forest expansion reached a maximum, suggesting increased winter moisture during early MIS 9e. Model‐data comparison for MIS 9e and 5e shows that insolation is the main driver of the orbital‐scale vegetation and precipitation changes in Iberia, atmospheric CO2 forcing playing a secondary role. The high‐frequency component of the MIS 9e and 5e forest timeseries highlights the early interglacial forest and precipitation maxima as prominent suborbital events lasting ∼2 ky. We propose that the primarily insolation‐driven forest and precipitation optima were fostered by the non‐equilibrium conditions generated by the millennial‐scale deglacial variability during the early interglacials. Additionally, the early end of these optima may have been favored by a cooling and drying event that is part of the persistent intra‐interglacial variability.
(Paleoceanography and Paleoclimatology. vol. 39, n° 2572-4525, pp. e2024PA004846, 23/02/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, CCMAR, UAlg, IPMA, IDAEA, CSIC
Influence of a hydroelectric dam on fish mercury contamination along the Sinnamary River (French Guiana)
The Petit Saut hydroelectric dam and the upstream and downstream areas of the Sinnamary River in French Guiana (Amazon basin) have been studied from 1993 to 2020. The nearly thirty-years-long study of the monitoring of total mercury concentration in fish and the physicochemical survey of the environment made it possible to demonstrate the impact of the flooding of the forest and the role of the hydroelectric dam on the methylation of mercury. Results show that the physicochemical modifications generated by the construction of the dam led to a significant production of methylmercury (MeHg) in the anoxic part of the reservoir and downstream of the river leading to a strong spatio-temporal impact of the dam. Seven species of fishes are studied and their mercury concentrations vary according to many parameters: fish diet, position in the water column, site, lake oxycline level and time.
(Ecotoxicology and Environmental Safety. vol. 269, n° 0147-6513, pp. 115771, 23/02/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Temporal distribution of microplastics and other anthropogenic particles in four marine species from the Atlantic coast (France).
The characterization of microplastic (MP) contamination in marine species is increasing as concerns about environmental and food safety are more and more discussed. Here, we reported a quantitative and qualitative assessment of the contamination by anthropogenic particles (from visual sorting; AP) and MP (plastic-made) in the whole soft body or digestive tract of marine species. Four commercial species were studied, namely the Pacific oyster (Magallana gigas), the spiny spider crab (Maja sp.), the common sole (Solea solea) and seabass (Dicentrarchus labrax or punctatus). AP and MP uptake were studied over three to four seasons depending on the species. After tissues digestion, particles were extracted under a stereomicroscope and morphometric characteristics were reported. Then, polymers were identified by ATR-FTIR spectroscopy. Seasonal variations were mainly described in the Pacific oyster as AP uptake was lower in autumn and MP uptake was higher in spring. These variations may be linked to the reproduction and growth cycles of this species. Moreover, seabass ingestion was lower in autumn compared to winter. Contamination in spider crabs and soles showed either weak or no seasonal trends, both quantitatively and qualitatively. Overall, AP contamination in all studied species ranged from 1.17 ± 1.89 AP.ind (in sole) to 4.07 ± 6.69 AP.ind (in seabass) while MP contamination ranged from 0.10 ± 0.37 MP.ind (in sole) to 1.09 ± 3.06 MP.ind (in spider crab). Fibers were mostly reported in all species (at least 77.7%), along with cellulosic polymers (at least 43.7%). AP and MP uptake were detected in all species and at almost all seasons, with the only exception of the common sole during autumn. Therefore, this study emphasizes the ubiquity of AP and MP contamination in marine species and provides new knowledges about seasonal uptake by commercial species.
(Environmental Pollution. vol. 357, n° 0269-7491, pp. 124440, 23/02/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, CBMN, UB, ENITAB, INC-CNRS, CNRS
Cardiac and neurobehavioral impairments in three phylogenetically distant aquatic model organisms exposed to environmentally relevant concentrations of boscalid.
Boscalid (2-Chloro-N-(4′-chlorobiphenyl-2-yl) nicotinamide), a pyridine carboxamide fungicide, is an inhibitor of the complex II of the respiration chain in fungal mitochondria. As boscalid is only moderately toxic for aquatic organisms (LC$_{50}$ > 1–10 mg/L), current environmental levels of this compound in aquatic ecosystems, in the range of ng/L-μg/L, are considered safe for aquatic organisms. In this study, we have exposed zebrafish (Danio rerio), Japanese medaka (Oryzias latipes) and Daphnia magna to a range of concentrations of boscalid (1–1000 μg/L) for 24 h, and the effects on heart rate (HR), basal locomotor activity (BLA), visual motor response (VMR), startle response (SR), and habituation (HB) to a series of vibrational or light stimuli have been evaluated. Moreover, changes in the profile of the main neurotransmitters have been determined. Boscalid altered HR in a concentration-dependent manner, leading to a positive or negative chronotropic effect in fish and D. magna, respectively. While boscalid decreased BLA and increased VMR in Daphnia, these behaviors were not altered in fish. For SR and HB, the response was more species- and concentration-specific, with Daphnia exhibiting the highest sensitivity. At the neurotransmission level, boscalid exposure decreased the levels of L-aspartic acid in fish larvae and increased the levels of dopaminergic metabolites in D. magna. Our study demonstrates that exposure to environmental levels of boscalid alters cardiac activity, impairs ecologically relevant behaviors, and leads to changes in different neurotransmitter systems in phylogenetically distinct vertebrate and invertebrate models. Thus, the results presented emphasize the need to review the current regulation of this fungicide.
(Environmental Pollution. vol. 347, n° 0269-7491, pp. 123685, 23/02/2026)
IDAEA, CSIC, URL, CID-CSIC, CSIC, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Pseudopolydora kempi japonica Imajima & Hartman, 1964 (Polychaeta: Spionidae): a controversial subspecies long overlooked in European waters
Recently, using morphological and molecular analyses, several Pseudopolydora specimens (Polychaeta: Spionidae) from French coastal waters were identified as Pseudopolydora kempi ssp. japonica Imajima and Hartman, 1964. According to the samples examined, P. kempi ssp. japonica has been present in European waters since 2004. Previous misidentifications in France are likely due to its resemblance to the indigenous species Pseudopolydora pulchra (Carazzi, 1893), and to the status of P. kempi ssp. japonica which is still controversial. Material was collected from Arcachon Bay, Morbihan Bay, Aiguillon Bay, and in the Gironde estuary (Bay of Biscay, France). All these areas have extensive shellfish industries, especially the farming of the Japanese oyster Magallana gigas (Thunberg, 1793). The importation of these live oysters from Japan has often included other species including polychaete worms, indicating a major vector of exotic species.
(BioInvasions Records. vol. 32, n° 2242-1300, pp. 403-418, 23/02/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UMS POREA, INSU - CNRS, CNRS, INRAE, LIENSs, INSU - CNRS, ULR, CNRS