The role of biomolecules produced by invasive macrophytes in lake ecosystem processes
Egeria densa and Lagarosiphon major are the main invasive hydrophytes in French Atlantic Lakes. These exotic species can modify trophic levels by producing large quantities of biomass in lakes; previous investigations revealed the occurrence of endogenous metabolites in these plants known to be able to affect epiphytic communities, phytoplankton, or other plants, through allelopathic activity. Nevertheless, the actual excretion and environmental occurrence of these metabolites remain poorly documented. In order to gain knowledge of the concrete occurrence and potential ecological impact of E. densa and L. major exometabolome, untargeted metabolomics using high-resolution mass spectrometer and chemometrics approaches is relevant through its ability to depict, as a first step, the exometabolome chemical landscape.
(01/01/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UR EABX, INRAE
Oceanic and climatic dynamics during the MIS 12–11 transition in the Gulf of Cádiz: Insights from coccolithophores
This study reconstructs environmental variability and surface-ocean dynamics across Termination V (MIS 12-11) in the Gulf of Cádiz using coccolithophore assemblages from International Ocean Discovery Program (IODP) Site U1386. Our data, combined with independent palaeoenvironmental proxies, including sea surface temperatures (SST), ice-rafted debris (IRD), benthic δ 18 O, and Mediterranean forest pollen assemblages, reveal a marked increase in coccolithophore productivity during MIS 11 compared to MIS 12. The end of the glacial period is characterised by higher abundances of Gephyrocapsa oceanica and reworked calcareous nannofossils, suggesting intensified Mediterranean Outflow Water (MOW). High abundances of the cold-water species Coccolithus pelagicus subsp. pelagicus, together with low SSTs and reduced Mediterranean forest pollen, reflect cold and dry conditions that were unfavourable for coccolithophore proliferation. These patterns suggest a weak westerly influence over southwestern Iberia, resulting in reduced precipitation and limited upwelling during the end of the MIS 12. In contrast, MIS 11 suggests stronger westerly influence, promoting wetter conditions and higher productivity. A sharp decline in productivity around 430 ka corresponds to a cooling event associated with increased IRD deposition, likely related to Heinrich-type event 4. These findings provide new insights into the coupling between atmospheric circulation, ocean dynamics, and primary productivity during the Mid-Brunhes Event.
(Palaeogeography, Palaeoclimatology, Palaeoecology. vol. 681, n° 0031-0182, 01/01/2026)
CIDIS, UPCH, UC Santa Cruz, UC, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Northernmost record in the Bay of Biscay (northeastern Atlantic) of two leptothecate hydroids (Cnidaria: Hydrozoa) of southern affinity
Two leptothecate hydroids of southern affinity, Sertularella ornata Broch, 1933 and Sertularelloides cylindritheca (Allman, 1888) were collected in the southern sector of the Bay of Biscay off Saint Jean de Luz (France). The latter was also seen during several ROV surveys on rocky communities along the Cantabrian Sea and northwestern Spain. Each of the two species is herein described and illustrated and their worldwide distribution, bathymetric ranges and reproductive periods, revised; additionally, we allocate them in their biocoenological context, providing in situ images. The northern boundary limits are extended for both hydroids, which are new records for the Atlantic coast of France; the latter belongs to a genus previously unrecorded in the French mainland fauna. We also discuss the importance of having inventories of the sessile fauna of the exceptional sites at study, for the sake of their protection and detection of future modifications due to climate change.
(Journal of Marine Systems. vol. 253, n° 0924-7963, pp. 104158 (11p.), 01/01/2026)
INSUB, LERAR, COAST, IFREMER, IEO | CSIC, CSIC, LERPAC, COAST, IFREMER, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
In situ monitoring of LNAPL-contaminated aquifer remediation using ultraviolet light-induced fluorescence imaging
Groundwater contamination by light non-aqueous phase liquids (LNAPLs) represents a major environmental challenge, requiring efficient and adaptive remediation methods. This study proposes and validates an innovative implementation of an in situ monitoring technique for LNAPL remediation treatments, based on ultraviolet lightinduced fluorescence imaging (UVIF), combined with automated image post-treatment, to enable in situ and realtime monitoring of decontamination processes. Specifically, a mini-camera integrated into a set of transparent wells embedded in the subsurface of LNAPL-contaminated zones was used to monitor both a surfactant injection remediation process and a skimming operation involving groundwater drawdown. The technique was first calibrated and validated through laboratory and pilot-scale experiments, then tested on a real site, which was contaminated with diesel. The pilot test revealed differences of less than 5 % between recovery factors obtained via gas chromatography (GC) of soil samples and those measured with the proposed imaging technique. Sitespecific calibration correlated fluorescence intensity from endoscopic images in transparent tubes with GCanalyzed LNAPL content, showing a strong correlation (R² = 0.993) and relative errors below 10 %. This enabled accurate in situ estimation of LNAPL variations: content remained mostly unchanged without treatment (<5 % variation), decreased moderately during pumping and skimming (≈35 %), and dropped substantially during surfactant injection (≈60 %).This capability supports immediate treatment adjustments, thereby optimizing pollutant recovery rates. Beyond simple monitoring, the results demonstrate that UVIF can effectively guide remediation operations by providing rapid feedback (near real-time) on contaminant removal dynamics.
(Journal of Hazardous Materials. vol. 501, n° 0304-3894, 01/01/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, I2M-BX, UB, CNRS, INRAE
First and disturbing records of the bivalve molluscs Potamocorbula amurensis (Schrenck, 1861) and Mulinia lateralis (Say, 1822) in the Bay of Biscay (France)
The bivalve mollusc Potamocorbula amurensis, a Corbulidae from the Asian coasts, was recorded for the first time in France in September 2023 in the Gironde estuary, and subsequently in September 2024 in Aiguillon Cove and Aytré Bay. In Aytré Bay, it was accompanied by another non-native bivalve not previously reported from French coasts, Mulinia lateralis, a Mactridae from the western Atlantic coasts. These two species were first recorded in Europe in 2018 in the Westerschelde (Netherlands, Belgium) and are known to be potentially highly invasive. Particular attention should be paid to monitor the spread and the establishment of these two euryoecious species along European coasts.
(An Aod - Les cahiers naturalistes de l’Observatoire marin, n° 2263-5718, 10/07/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LIENSs, INSU - CNRS, ULR, CNRS, OBIONE, LIENSs, INSU - CNRS, ULR, CNRS, LPO, PatriNat, MNHN, IRD, CNRS, OFB - DSUED, OFB, PatriNat, MNHN, CNRS, OFB, PatriNat, MNHN, CNRS, AFB
Organic carbon composition and preservation in macrotidal coastal wetland sediment: insights from biomarkers and isotopic signatures
Coastal wetlands store high amounts of organic carbon (OC) in their sediments, but long-term preservation of this carbon depends on habitat type, sediment depth, and the molecular characteristics of organic matter (OM). This study explores the dynamics of OC deposition and preservation across vertical profiles (0–30 cm) in two adjacent coastal habitats—mudflat, and salt-marsh—within the macrotidal system of the Aiguillon Bay (France). A multi-tracer approach was applied, combining stable isotopes δ13C, C/N ratios, lignin phenols, and fatty acids. Sediment OC content ranged from 13.4 to 23.2 mgC g−1, with the highest concentrations found in the salt-marsh. δ13C and C/N signatures revealed dominant marine source in the mudflat, with a secondary contribution from microphytobenthos, and mixed marine–C₃ plant inputs in the salt-marsh. Fatty acids and lignin compositions supported this partitioning, with surface mudflat layers enriched in labile microbial and algal-derived compounds, whereas deeper salt-marsh sediments retained more resistant, C3 plant-derived signatures resembling those of terrestrial OM source. OM degradation rates were closely linked to source composition and depth. Degradation was concentrated within the top 5 cm of salt-marsh and the top 10 cm of mudflat. Below these depths, biomarker profiles changed minimally, delineating a transition to longer-term preservation. First-order degradation constants were three times higher in mudflat (0.53 yr−1) than in salt-marsh (0.17 yr−1), despite similarly high sedimentation rates (1.8 and 2.2 cm yr−1, respectively). This reflects differences in OM lability, with even minor contributions from microphytobenthos enhancing reactivity in mudflats. Salt-marshes, with their intermediate OM reactivity and high sedimentation rates, emerged as hotspots of carbon accumulation (366 gC m−2 yr −1), while mudflats also contributed substantially to coastal carbon sequestration (239 gC m−2 yr −1). These results highlight the value of depth-resolved, biomarker-based approaches to identify habitat-specific degradation dynamics; ultimately better understanding carbon accumulation in coastal ecosystems.
(Science of the Total Environment. vol. 1020, n° 0048-9697, pp. 181542, 10/07/2026)
LIENSs, INSU - CNRS, ULR, CNRS, iEES Paris, IRD, SU, UPEC UP12, CNRS, INRAE, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LPG-ANGERS, LPG, UM, UA, INSU - CNRS, CNRS, Nantes univ - UFR ST
Faire face aux polluants éternels
(10/07/2026)
LEESU, UPEC UP12, ENPC, IP Paris, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Migration des dunes côtières et évaluation de l'aléa
Dans un contexte où la remobilisation des systèmes dunaires peut apparaître spontanément où être envisagée comme une solution de gestion fondée sur la nature apportant de multiples avantages écosystémiques (reconnexion écologique, atténuation des effets de l'érosion marine chronique et de l'élévation du niveau de la mer), il est nécessaire d'être en mesure d'évaluer et d'anticiper les impacts de la migration dunaire en termes de risques. En effet, dès lors que la couverture de végétation est fortement déstabilisée (conditions climatiques, ensevelissement ou perturbations anthropiques), la dynamique sédimentaire prend le dessus sur les facteurs de contrôle biotiques et la dune se met à rouler sur ellemême (« rollover » éolien). Sans intervention, ce processus peut perdurer pendant plusieurs décennies voire siècles, sans que la végétation soit en mesure de refixer spontanément ces dunes en migration. Ainsi l'évaluation des taux de migration des dunes en libre évolution soulève inévitablement la question du risque d'ensevelissement des infrastructures, des biens ou plus généralement des espaces situés en arrière. Sur la base de suivis topographiques sur une décennie, cette contribution explore le rôle de divers paramètres externes (forçages) et internes (caractéristiques du système dunaire) influant sur la vitesse de migration de plusieurs secteurs en rollover dans le sud-ouest de la France. Ces exemples comprennent des dunes de formes et dimensions variables, en migration à long terme ou récemment remobilisées. Cette approche, en se basant sur les caractéristiques locales des forçages, de la morphologie dunaire et retro-dunaire, permet de compléter l'approche classique d'évaluation de l'aléa migration dunaire basée uniquement sur l'analyse par photo-interprétation des mouvements passés des dunes et qui s'avère inapplicable sur des dunes en remobilisation récente.
(10/07/2026)
BRGM, ONF, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Sustainability ranking of antifouling coatings for leisure boats – Balancing efficacy and environmental impact
Antifouling coatings are widely used on leisure boats to prevent biofouling, yet their environmental impacts vary significantly depending on formulation. This study systematically evaluated seven commercial antifouling products, including five copper-based coatings (with varying cuprous oxide content), one tralopyril-based coating and one biocide-free silicone foul-release coating. The evaluation included three complementary approaches: field-based efficacy testing, environmental risk assessment (ERA) modeling and ecotoxicological assays. Field trials were conducted over six months at three European coastal sites (Skagerrak, Kattegat and Atlantic) to assess the antifouling performance. Biocide release rates were quantified using X-ray Fluorescence and used to model environmental risks in accordance with EU guidelines. Acute toxicity of leachates was tested on four marine species (Aliivibrio fischeri, Phaeodactylum tricornutum, Artemia salina larvae and Oryzias melastigma larvae). The biocide-free silicone coating ranked highest in sustainability, combining strong antifouling efficacy with minimal acute toxicity. The copper-based coatings typically showed comparable efficacy at all sites despite differences in copper release but some only passed ERA thresholds in one of the sites (Atlantic). Lower copper content formulations generally exhibited reduced environmental impact. The tralopyril-based coating, despite being marketed as “environmentally safe”, demonstrated the highest toxicity and environmental risk. These findings highlight the need for environmental assessment of antifouling products to validate environmental safety claims and to promote lower impact formulations. While ERA modeling is suitable for biocidal products, ecotoxicological testing remains essential for biocide-free alternatives. Improved and standardized leaching protocols are needed to better reflect real-world conditions and support sustainable product development.
(Journal of Hazardous Materials. vol. 506, n° 0304-3894, pp. 141600, 10/07/2026)
OFB, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, GU, DTU, UMR MARBEC, IRD, IFREMER, CNRS, UM
Determinants of residential pesticide contamination in vineyard regions: a structural equation modeling approach
Background Previous studies have associated pesticide exposure among people living near fields with adverse health outcomes. However, the factors influencing residential contamination by agricultural pesticides remain unclear. Objective This study aims to assess the effect of the local environment, home characteristics, and occupant behaviors on residential contamination. Methods In 2021, wipe samples from outdoor and indoor surfaces were collected in 28 homes in Bordeaux vineyard region during peak pesticide spraying. Eight fungicides were analyzed by LC-MS/MS or GC-MS/MS. Environmental, residential, and occupant-related data were gathered through questionnaires and databases. Using multilevel structural equation modeling, we simultaneously examined the effects of multiple factors on pesticide contamination outdoors (Model 1, n = 227 samples) and indoors (Model 2, n = 543 samples), reporting standardized beta coefficients. Results Outdoor pesticide contamination was positively associated with local vineyard areas (beta = 0.79, p = <0.001) and the probability of a recent pesticide application (beta = 0.34, p = 0.09). In contrast, daily wind speed (beta = -0.54, p = 0.001), cumulative rainfall over the past month (beta = -0.32, p = 0.03), and cleaning (beta = -0.37, p < 0.001) were negatively associated with outdoor contamination. Indoor contamination was significantly associated with the annual local purchases of pesticides (beta = 0.79, p < 0.001) and pesticide track-in by occupants (beta = 0.16, p < 0.001). Conversely, households with active adults and children (beta = -0.49, p < 0.01), cleaning (beta = -0.40, p < 0.001), and surface contact frequency (beta = -0.30, p < 0.001) showed significant negative associations. Air exchange exhibited only a weak suggestive association (beta = 0.07, p = 0.09). Both models demonstrated good fit indices. Significance These results improve our understanding of residential pesticide contamination and could help inform the design of strategies to reduce exposure in rural populations.
(Journal of Exposure Science and Environmental Epidemiology, n° 1559-0631, 10/07/2026)
CHU Bordeaux, BPH, UB, INSERM, Irset, UA, UR, EHESP, INSERM, Biosit : Biologie - Santé - Innovation Technologique, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, ECOSYS, INRAE