Nationwide monitoring of seabirds reveals species- and site-specific legacy PFAS contamination in French coastal areas
Per-and poly-fluoroalkyl substances (hereafter PFAS) are widespread and persistent compounds that pose a threat to human and wildlife health. Wildlife monitoring is essential to understand the extent of PFAS contamination and its ecological drivers. Seabirds are good bioindicators of PFAS contamination of the marine environment, yet some areas, including the French coastlines, remain poorly covered. Here, we quantified 11 legacy PFAS in the plasma of 9 seabird species (n = 340 chicks) from 30 sites along the French Atlantic and Mediterranean coasts. Linear perfluorooctanesulfonic acid was by far the most abundant PFAS. Oceanic piscivorous species (Northern gannets Morus bassanus, black-legged kittiwakes Rissa tridactyla and Scopoli's shearwaters Calonectris diomedea) had the highest PFAS concentrations compared to Larus sp. gulls and shags Gulosus aristotelis. Overall, Mediterranean seabirds had lower perfluoroalkyl sulfonic acid and higher perfluoroalkyl carboxylic acid concentrations compared to Atlantic seabirds. At a finer spatial scale, chicks sampled near estuaries had a slightly higher PFAS burden, suggesting local riverine inputs. This first large-scale survey of PFAS in French seabirds reveals substantial heterogeneity in PFAS contamination across French coastal environments. Future work should address the sources of this PFAS contamination and quantify its toxicological consequences, given that sampled chicks may be at risk based on previous avian studies reporting PFAS-related health effects.
(Environment International. vol. 214, n° 0160-4120, pp. 110386, 01/08/2026)
CEBC, ULR, CNRS, INRAE, LIENSs, INSU - CNRS, ULR, CNRS, LPO, PatriNat, MNHN, IRD, CNRS, OFB - DSUED, OFB, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, CCEM, IFREMER, MIVEGEC, CNRS, IRD [Occitanie], IRD, UM, CEN Corse, BEEP, IFREMER, UBO EPE, CNRS, LPTC, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
µFTIR detection of tyre wear particles: A new analytical process using neural network modeling to attempt their identification
Tyre wear particles (TWPs) are a major source of microplastic contamination. Detection and quantification of TWPs in the environment is a major challenge. However, several methods are currently used, with their own advantages, disadvantages and limitations. In this study, a new method based on infrared micro spectroscopy was developed. In contrast to more conventional approaches based on spectral matching of characteristic peaks, a multi-criteria designation using a heatmap was chosen. This method was developed using absorbance and average spectral variation. These criteria were chosen due to their high potential for distinguishing carbon black filled. A neural network deep learning model was trained using spectral data from various microplastics and sediments. To test the detection performance of the model, the model was tested on some samples containing a known number of tyre particles. The method demonstrated high detection efficiency without false positives. However, the few particles omitted were associated with the use of a filter not perfectly flat. Analyses testing the method on a filter containing sediment from a stormwater pond revealed the presence of numerous particles corresponding to TWPs. This method is an innovative and promising approach for further studies on TWPs. Repeated application and continuous model training should improve its reliability, including more complex environmental matrices.
(Talanta Open. vol. 13, n° 2666-8319, pp. 100656, 01/08/2026)
ULR, LIENSs, INSU - CNRS, ULR, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Chronic exposure to sodium fluoride or to tebuconazole disrupts the thyroid hormone and immune systems during early development of rainbow trout (Oncorhynchus mykiss)
Over the past 20 years, there has been a growing interest in endocrine-disrupting chemicals (EDCs) found in both terrestrial and aquatic environments. These substances have garnered attention from scientists, the public and regulatory bodies, with many being classified as substances of very high health concern. Only recently, disruption of the thyroid hormone system (THS) by EDCs has also attracted significant attention: In vertebrates, the THS interacts with various physiological systems, including the immune system (IS), and plays a crucial role in development. It can also influence the microbial diversity in certain tissues. The main objective of this study was to investigate the potential impact of sodium fluoride (NaF) on the THS and IS in rainbow trout ( Oncorhynchus mykiss ), a species of both economic and environmental importance. For this end, trout were exposed from the embryonic stage (48 h post-fertilisation) to the juvenile stage for 7 months. Fish were subjected to 1.5 mg F-/L or 5 mg F-/L and 20 µg/L tebuconazole (TBZ; positive control) monitored daily and sampled after 3 and 7 months of exposure to assess potential disruption to the thyroid hormone and immune systems. Results document that chronic exposure to NaF or TBZ during early life stages of rainbow trout induces a broad range of sublethal effects, including physiological condition, immune competence, endocrine regulation and organ morphology. Although mortality was reduced, most probably due to the antifungal activity of TBZ, the consistent alterations observed in thyroid hormone dynamics and immune parameters clearly indicate a deterioration of overall health.
(Aquatic Toxicology. vol. 297, n° 0166-445X, pp. 107867, 01/08/2026)
VIMEP, ANSES, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, ANSES, VU, COS, UB
Geological and Geomorphological Controls on Rocky Shore Platforms: Insights from the Basque Coast, France
Rocky shore platforms are critical coastal landforms whose morphology reflects the interplay between geological inheritance, sea-level history, and erosional processes. While Sunamura’s (1992) classification distinguishes three main platform types (A, B, C), the detailed morphology of these features—especially their submerged components—remains poorly understood due to limited access. Here, we investigate the geological and geomorphological controls on shore platform development along the Basque Coast (France), using high-resolution bathymetric data acquired during the SPLASHALIOT-1 cruise (R/V Haliotis, 2014). Our study focuses on two sites near Saint-Jean-de-Luz: Socoa (a long-term monitoring site of the Dynalit national observatory) and Kokotia, both underlain by Cretaceous–Paleogene turbidites deformed during the Pyrenean orogeny. By integrating bathymetric mapping, and geological observations, we reveal that both sites exhibit the characteristics of a Type A platform (sensu Sunamura, 1992): a planar, gently sloping surface (1–2°) extending 100–500 m offshore. The platform morphology is strongly influenced by lithological layering, with resistant turbidite beds shaping roughness and structural features. Notably, we observe no seaward cliff, challenging the hypothesis of ubiquity of low-tide cliffs in models of rocky coast evolution. Geological mapping extends onshore stratigraphy offshore, highlighting thrusts and normal faults (e.g., the Bidart–Pointe Sainte Anne Fault) that compartmentalize the platform. Our results suggest that platform morphology primarily records Holocene sea-level stabilization, with limited evidence of deeper terraces from the Last Interglacial (MIS5). The absence of prominent scarps or stepped features implies that cliff retreat rates (4–20 cm/a) have been insufficient to preserve older morphologies. We further discuss how structural roughness and lithological contrasts modulate wave energy dissipation, with implications for future cliff retreat under sea-level rise. This study underscores the need to account for geological heterogeneity in predictive models of rocky coast evolution.
(Bulletin de la Société Géologique de France, n° 0037-9409, 28/07/2026)
GET, IRD, INSU - CNRS, CNES, CNRS, EPE UT, Comue de Toulouse, Comue de Toulouse, LPG, UM, UA, INSU - CNRS, CNRS, Nantes univ - UFR ST, Nantes Univ, LPG-ANGERS, LPG, UM, UA, INSU - CNRS, CNRS, Nantes univ - UFR ST, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, BRGM, GEO-OCEAN, UBS, IFREMER, INSU - CNRS, UBO EPE, CNRS, LOMC, ULH, NU, CNRS, ULH, NU, NU, OMP, IRD, INSU - CNRS, CNES, CNRS, EPE UT, Comue de Toulouse
Spatiotemporal Trends in Nutrient-Related Pollution Along the Adour River-Estuary Continuum, a Mesotidal System in the Bay of Biscay
(17/07/2026)
IPREM, UPPA, INC-CNRS, CNRS, iEES Paris, INRA, SU, UPEC UP12, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, SIAME, UPPA, MIO, IRD, AMU, INSU - CNRS, UTLN, CNRS
Contamination des sols français par les résidus de pesticides
La contamination de l’environnement par les résidus de pesticides est une préoccupation croissante par les acteurs publics au vu de leur omniprésence dans tous les milieux et leurs impacts directs et indirects sur la biodiversité et la santé humaine. Cependant, les études traitant de la contamination des sols par les résidus de pesticides sont très peu nombreuses, témoignant du manque de connaissance sur l’état de la contamination des sols et les impacts potentiels sur la biodiversité. Le projet Phytosol, financé entre 2018 et 2022 par l’Anses et coordonné par INRAE a permis d’acquérir des données inédites de 111 substances sur 47 sols prélevés dans le cadre du Réseau de mesures de la qualité des sols (RMQS). Les résultats de cette étude, détaillés dans le rapport suivant et publiés en 2023 dans la revue Environmental Science Technology, démontrent ainsi que 98% des sols prélevés contiennent au moins un résidu de pesticides, y compris des sites sans traitements phytosanitaires tels que les prairies permanentes, les sols forestiers ou encore des sols de parcelles en agriculture biologique. L’évaluation des risques indique également un risque modéré à fort pour les vers de terre notamment dans les sols de grandes cultures. Enfin, la confrontation avec les applications de produits phytosanitaires a mis en évidence la présence de certaines substances bien au-delà de leur temps de dégradation théorique et à des concentrations supérieures à celles attendues. Le déroulement de l’étude (mise en place, méthodologie) ainsi que les résultats détaillés sont présentés dans ce rapport.
(15/07/2026)
Info&Sols, INRAE, LPTC, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Evaluating migration hazard for recently remobilized managed coastal dunes
Sparsely vegetated or unvegetated coastal dunes are inherently dynamic, regardless of their size (Hesp et al., 2022). A salient characteristic of these dunes is their landward migration, driven by prevailing onshore winds, at rates that can exceed several meters per year. The rapid evolution of freely evolving coastal dunes inevitably raises concerns about the burial of infrastructure and more generally, the back dune areas. In a context where dune system remobilization is emerging as a nature-based management solution with multiple benefits (ecological reconnection, chronic marine erosion and sea-level rise effects mitigation), precise, spatially explicit quantitative assessments of dune migration hazards are essential. This is more critical given the trends of increasing urbanization and the concentration of socio-economic interests in coastal zones. Along the 230 km of the Aquitaine coast (southwest France), coastal dunes, which landscape is largely inherited from nearly two centuries of management, stabilization, and episodic mechanical re-profiling, have undergone spontaneous remobilization over the past decade (Nicolae Lerma et al., accepted). Across extensive sectors, dunes have transitioned from geometrically fixed, vegetated forms to aerodynamic, transgressive dunes (Figure 1a). This shift presents both opportunities and challenges for short- and long-term management strategies but also raises critical questions about accommodating rapid migration rates and evolving dune morphology. Current approaches to assessing burial hazards often overlook key parameters, such as interannual wind variability, climate change-induced trends in forcing, dune and back-dune morphology, and sediment budgets. Furthermore, methods relying on historical migration rates are inapplicable in regions where dunes were artificially stabilized during the 20th century through management interventions. Using annual airborne LiDAR data (Figure 1b.) and simulations with the morphodynamic model DUNA (Kombiadou et al., 2023, Figure 1c.), we analyze the factors influencing the migration speed of recently unvegetated dunes. We also investigate the impact of hybrid management strategies (designed to either accelerate or mitigate dune remobilization) at large spatial scales (hundreds of meters to tens of kilometers).
(13/07/2026)
BRGM, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, ONF
Early development of a restored dune system positioned in front of a dyke on a chronically eroding microtidal urban shoreline
Coastal dunes are globally recognized as natural features that can be important adaptation approaches for climate change along urban and natural coastal system. The aim of the study is to investigate the effects of sand trapping fences installed in front a grey dyke along a 2300-meter stretch of coastline in St. Marie-La-Mer (Southeastern France) in November 2021. This area has been experiencing severe chronic erosion for several decades. The methodology involves analyzing bi-annual topographic Lidar surveys conducted between May 2020 and September 2023, along with an examination of hydro-meteorological conditions. The research indicates several sediment balances within the traps between October 2021 and September 2023, with volumes in stability -0.05 m3/m2 (-14 m3) at the more eroding zone and in exceeding between 0.2 and 0.35 m3/m2 (1200 m3) elsewhere. The erosive trend preceding October 2021 has ceased, with each DEM demonstrating stability or gain. Throughout the study, the beach’s sediment budget remains negative (ranging between -0.12 and -0.27 m3/m2, -6100 m3) except in SA2. Thus, despite adverse conditions for aeolian sediment transport and deposition, such as narrow and steep beach, predominant offshore wind, coarse grain size, limited sediment supply, slow vegetal colonization, along with persistent erosion of the lower beach, initial stages of upper beach restoration are encouraging. Moreover, this soft dune management approach is expected to mitigate the impacts of major storm events. This was observed in 2021 and 2022 where two significant storms (Hs>5m), had minimal impact on the upper beach compared to past incidents where similar conditions led to deterioration of the incipient dune and the dyke. This study provides valuable insights into the implementation of such systems in environments prone to chronic erosion and unfavorable conditions for aeolian sediment transport
(12/07/2026)
BRGM, UniFE, UM, UM, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UB
Plages et baignades : dix conseils pour profiter pleinement de l’océan cet été
Que signifie un drapeau jaune sur une plage ? À quel moment les courants de baïnes sont-ils les plus intenses ? Que faire si un courant nous emporte au large ? Le point sur les choses à savoir pour se baigner en toute sécurité. La plage est un environnement exceptionnel, et notre territoire possède une façade maritime extrêmement étendue. Cet été, il est fort probable que le littoral reste la première destination touristique des Français.
(11/07/2026)
UR ETTIS, INRAE, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Coastal barchanoid dunes differentiation and evolution model: Cap Ferret Spit, Aquitaine Coast France
Barchanoid dunes fields are commonly observed in both desert and coastal areas. However, while they are relatively well known in arid settings, their internal architecture, dune morphology and evolution processes in coastal environments are rarely documented in the literature. This study investigates coastal barchanoid dunes along the Cap Ferret Spit (southwest France) by combining high-resolution LiDAR data (1 m spatial resolution) with an extensive ground-penetrating radar (GPR) survey (>70 km of profiles). Five distinct dune morphotypes are identified along an ocean-spit-lagoon continuum, as modern foredune, embryonic dunes, proto-barchans, barchanoid ridges, and isolated barchans. Morphometric analyses reveal systematic relationships between dune size, elevation, and internal structure, with crest elevations ranging from 5 m in proto-barchans to 40 m in barchanoid ridges and isolated barchans. GPR profiles image lee-side accretion strata, reactivation surfaces, superimposed structures, and dune-dune interaction features, demonstrating that proto-barchans grow through stacking before evolving into barchanoid ridges and subsequently fragmenting into isolated barchans. The Cap Ferret dune system enables observation of preliminary and intermediate developmental stages of barchanoid dunes rarely documented in the literature, from embryonic dunes through proto-barchans and compound forms to isolated barchans. Second-order morphologies, including superimposed bedforms and wavy patterns with transverse orientation, occur systematically across all dune types and record short-term reactivation processes driven by dominant winds and potential vegetation interactions. These findings provide a reference model for coastal dune morphodynamic transitions including interactions between aeolian, hydrologeological and biotic processes. It also contributes to refining conceptual and numerical models of dune-field evolution by incorporating coastal boundary conditions.
(Geomorphology. vol. 511, n° 0169-555X, pp. 110441, 10/07/2026)
BRGM, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS