Toxicité des microplastiques et des nanoplastiques vis-à-vis d'organismes aquatiques le long d'un continuum eau douce-eau de mer
(21/06/2026)
BIOSSE, UCO, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, CNRS, GR, UR, INSU - CNRS, CNRS, ULaval, INSU - CNRS, CNRS
Impacts of highway runoff on metal contamination including rare earth elements in a small urban watershed: case study of Bordeaux Metropole (SW France)
High temporal resolution sampling of runoff (15 samples/4 h) and river water (24 samples/24 h) was performed during a major rainstorm (41 mm/4 h) in the Bordeaux Metropole, after a dry and high vehicle-density period. Runoff was sampled at the outlet of one collector draining Northern Bordeaux Highway (NBH; 80,000–93,000 vehicles/day) and river water in the downstream Jalle River. The studied metals, including priority and emergent (Rare Earth Elements [REEs]) contaminants, showed major temporal and spatial variations in the dissolved and particulate concentrations. Hierarchical cluster analyses distinguished metal groups, reflecting different: (i) sources (i.e., automotive traffic: Zn–Cu–Ce and wastewater treatment plant: Cd–Ag–Gd) and/or (ii) processes (i.e., groundwater dilution by rainwater and sorption processes). The contribution of the particulate fraction to total metal fluxes was predominant in the NBH collector (except for Sr and Mo) and highly variable in the Jalle River, where the highest particulate metal loads were due to the export of road dusts exported by the NBH collector. Metal fluxes from the NBH collector represented highly variable fractions of daily fluxes into the Gironde Estuary at the outlet of the Jalle River, depending on elements and partitioning. The resulting relative contributions ranged from: 5% (Sr) to 40% (Cu) for dissolved phases and 30% (As) to 88% (Cu) for particulate phases. The first 40 min of the event accounted for 65% of the suspended particulate matter flux (and associated particulate metals) exported by the NBH collector, whereas the respective water flux contribution was 35%. This finding clearly demonstrates the importance of monitoring the first minutes of rainy events when establishing mass balances in urban systems.
(Archives of Environmental Contamination and Toxicology. vol. 193, n° 0090-4341, pp. 1-21, 21/06/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, I2M-BX, UB, CNRS, INRAE
High-resolution, large-scale laboratory measurements of a sandy beach and dynamic cobble berm revetment
High quality laboratory measurements of nearshore waves and morphology change at, or near prototype-scale are essential to support new understanding of coastal processes and enable the development and validation of predictive models. The DynaRev experiment was completed at the GWK large wave flume over 8 weeks during 2017 to investigate the response of a sandy beach to water level rise and varying wave conditions with and without a dynamic cobble berm revetment, as well as the resilience of the revetment itself. A large array of instrumentation was used throughout the experiment to capture: (1) wave transformation from intermediate water depths to the runup limit at high spatio-temporal resolution, (2) beach profile change including wave-by-wave changes in the swash zone, (3) detailed hydro and morphodynamic measurements around a developing and a translating sandbar.
(Scientific Data. vol. 8, n° 2052-4463, pp. 22, 21/06/2026)
SBMS, LEGOS, IRD, UT3, Comue de Toulouse, INSU - CNRS, CNES, CNRS, UNSW, UQ [All campuses : Brisbane, Dutton Park Gatton, Herston, St Lucia and other locations], UGent, UGent, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, FZK
Inter‐country differences in the cultural ecosystem services provided by cockles
Coastal systems provide many cultural ecosystem services (CES) to humans. Fewer studies have focused solely on CES, while those comparing CES across countries are even rarer. In the case of shellfish, considerable ecosystem services focus has been placed on nutrient remediation, with relatively little on the cultural services provided, despite strong historical, cultural, social and economic links between shellfish and coastal communities. The ecosystem services provided by the common cockle, Cerastoderma edule, have recently been described, yet the cultural benefits from cockles remain mostly unknown. Here, we documented the CES provided by C. edule in five maritime countries along the Atlantic coast of western Europe, classifying evidenced examples of services into an a priori framework. The high-level classes, adapted from the Millennium Assessment and the Common International Classification of Ecosystem Services, were: inspirational, sense of place, spiritual & religious, aesthetic, recreation & ecotourism, cultural heritage and educational. A further 19 sub-classes were defined. We followed a narrative approach to draw out commonalities and differences among countries using a semi-quantitative analysis. Examples of CES provided by cockles were found for all classes in most countries. Cockles supply important and diverse cultural benefits to humans across Atlantic Europe, making it an ideal model species to study CES in coastal areas. Most examples were in cultural heritage, highlighting the importance of this class in comparison with classes which typically receive more attention in the literature like recreation or aesthetics. We also found that the cultural associations with cockles differed among countries, including between neighbouring countries that share a strong maritime heritage. The extent to which cultural associations were linked with the present or past also differed among countries, with stronger association with the present in southern countries and with the past in the north. Understanding the wider benefits of cockles could deepen the recognition of this important coastal resource, and contribute to promoting sustainable management practices, through greater engagement with local communities. This study is an important step towards better integration of CES in coastal environments and could be used as a framework to study the CES of other species or ecosystems.
(People and Nature. vol. 4, n° 2575-8314, pp. 71-87, 21/06/2026)
CEH, NERC, ULISBOA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, ERI, UCC, BOREA, UNICAEN, NU, MNHN, IRD, SU, CNRS, UA, UNICAEN, NU, GEMEL-Normandie
Pesticide mixture toxicity assessment through in situ and laboratory approaches using embryo-larval stages of the pacific oyster (Magallana gigas)
Worsened state of oysters in French Arcachon Bay, demand an investigation of possible causes. This study evaluated the effects of an environmentally relevant mixture of five common pesticides on the early-life stages of the Pacific oyster (Magallana gigas). Laboratory assays with artificial mixture and in situ transplantation were complementarily used to investigate a series of sublethal endpoints. The laboratory exposure revealed developmental toxicity at 0.32 μg/L, which corresponds to mixture concentrations in Arcachon Bay. Downregulation of some gene transcriptions was observed at environmental level. No difference in larvae development was revealed among the three sites in Arcachon Bay. This study was the first to evaluate locomotion of oyster larvae exposed in situ. Suspected poor water quality in the inner part of Arcachon Bay was reflected by impairment at the molecular level. In conclusion, current concentrations of the tested pesticides in Arcachon Bay hinder larval development and affect several biological functions.
(Marine Environmental Research. vol. 169, n° 0141-1136, pp. 105390, 21/06/2026)
MU / MUNI, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Compte rendu de l'atelier national « espèces non indigènes » (ENI), 14.10.2021, MNHN Paris
(pp. 17 pages, 21/06/2026)
PatriNat, MNHN, CNRS, OFB, LERAR, COAST, IFREMER, LOG, INSU - CNRS, ULCO, CNRS, IRD [Ile-de-France], IUEM, IRD, INSU - CNRS, UBO EPE, CNRS, OFB, DYNECO, IFREMER, M2C, UNICAEN, NU, INSU - CNRS, UNIROUEN, NU, CNRS, MTES, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, IFREMER, LIENSs, INSU - CNRS, ULR, CNRS, LERPC, COAST, IFREMER, ECOSEAS, CNRS, UniCA, UICN, CRESCO, MNHN, IFREMER, MIO, IRD, AMU, INSU - CNRS, UTLN, CNRS, UMR ISEM, Cirad, IRD, EPHE, PSL, CNRS, UM
Reinterpreting the Bruun Rule in the Context of Equilibrium Shoreline Models
Long-term (>decades) coastal recession due to sea-level rise (SLR) has been estimated using the Bruun Rule for nearly six decades. Equilibrium-based shoreline models have been shown to skillfully predict short-term wave-driven shoreline change on time scales of hours to decades. Both the Bruun Rule and equilibrium shoreline models rely on the equilibrium beach theory, which states that the beach profile shape equilibrates with its local wave and sea-level conditions. Integrating these two models into a unified framework can improve our understanding and predictive skill of future shoreline behavior. However, given that both models account for wave action, but over different time scales, a critical re-examination of the SLR-driven recession process is needed. We present a novel physical interpretation of the beach response to sea-level rise, identifying two main contributing processes: passive flooding and increased wave-driven erosion efficiency. Using this new concept, we analyze the integration of SLR-driven recession into equilibrium shoreline models and, with an idealized test case, show that the physical mechanisms underpinning the Bruun Rule are explicitly described within our integrated model. Finally, we discuss the possible advantages of integrating SLR-driven recession models within equilibrium-based models with dynamic feedbacks and the broader implications for coupling with hybrid shoreline models
(Journal of Marine Science and Engineering. vol. 9, n° 2077-1312, pp. 974, 21/06/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, BRGM, USGS
Multidecadal Evolution of the Turbidity Maximum Zone in a Macrotidal River Under Climate and Anthropogenic Pressures
Climate and human pressures can influence the evolution of estuarine sediment dynamics concurrently, but the understanding and quantification of their cause–effect relationships are still challenging due to the occurrence of complex hydro-morpho-sedimentary feedbacks. The Garonne Tidal River (GTR, upper Gironde Estuary, France) is a clear example of a system stressed by both anthropogenic and climate change, as it has been subject to decreasing river discharges, natural morphological changes, and gravel extraction. To understand the relative effect of each hydrological and geomorphological pressure on the turbidity maximum zone (TMZ), the sediment dynamics in the GTR over the last six decades was evaluated using the width-averaged idealized iFlow model. Model results show a gradual increase in tidal amplitude and currents over the decades that has led to the upstream shift of the landward sediment-transport capacity components (external M4 tide, spatial settling lag, and tidal return flow). The upstream displacement of the TMZ between the 1950s and the 2010s was estimated to be at least 19 km, of which about three fourth was induced by geomorphological changes and one fourth by hydrological changes. Concerning the geomorphological changes, the natural evolution of the lower Gironde morphology was the main pressure inducing the displacement of the TMZ in the GTR. Anthropogenic and natural changes in morphology and bed roughness in the GTR itself also contributed to this evolution. The natural geomorphological changes were, in turn, probably promoted by the evolution of sediment dynamics, so this study reveals the closed circle that governs the intensification of the TMZ.
(Journal of Geophysical Research. Oceans. vol. 126, n° 2169-9275, pp. e2020JC016273, 21/06/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, TU Delft
Satellite-derived shoreline detection at a high-energy meso-macrotidal beach
Publicly available satellite imagery can now provide multi-decadal time series of shoreline data from local to global scale, enabling analysis of sandy beach shoreline variability across a spectrum of temporal scales. Such data can, however, be associated with large uncertainties, particularly for beaches experiencing a large tidal range (>2 m) and energetic incident waves. We use a decade of bi-monthly topographic surveys at the high-energy meso-macrotidal beach of Truc Vert, southwest France, and concurrent wave and water-level hindcast to investigate the uncertainties associated with satellite-derived time series of the shoreline position. We show that consideration of the water level and wave runup elevation is critical for accurately estimating waterline position and, in turn, shoreline position. At Truc Vert, including non-tidal water level residuals (e.g. wind-driven surge) and accounting for time- and elevation-varying beach slope for horizontal correction did not improve satellite-derived shoreline position. A new total water level threshold is proposed to maximize the number of usable images while minimizing errors. Accounting for wave runup and the new water level threshold at Truc Vert, the number of usable satellite images is doubled and shoreline position errors are at least halved compared to previous work at this site. Using the 1984–2019 reconstructed shoreline, we also show that the satellite-derived shoreline trends and interannual variability are in better agreement with field measurements. Although the approach proposed here needs to be tested on other sites in different tidal/wave forcing environments with different morphological and sediment characteristics, we anticipate that it will improve the temporal and spatial description of shoreline change on most surf tidal beaches where accurate continuous water level and wave hindcasts and/or observations are available.
(Geomorphology. vol. 383, n° 0169-555X, pp. 107707, 21/06/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, SBMS
Morphological and ecological responses of a managed coastal sand dune to experimental notches
In northern Europe, coastal dune remobilization by restoring natural processes is considered by some to maintain the coastal dune in chronically eroding sectors by migrating landward and to restore dune ecology. In wet climatic contexts, this nature-based solution has been shown to induce an increase in both sand bare areas and vegetation diversity. However, it has never been tested in the coastal dunes of southern Europe with a drier climate and, thus, more stressful conditions, where disturbance may inversely decrease vegetation diversity. An original experiment was set up in 2018 on a 4-km stretch of coastal dune in southwest France where Experimental Notches (EN) were excavated in the incipient foredune, referred to as West Experimental Notch (WEN), and in the established foredune, referred as to East Experimental Notch (EEN). Morphological and ecological responses were monitored using UAV photogrammetry and vegetation sampling along transects during two years with contrasted winter storm conditions. During the first winter characterized by calm wind conditions, a rapid filling of the WENs and the initiation of deposition lobes landward of the EENs were observed. Stronger winds during the second winter led to the development of deposition lobes of the EENs, increasing both their volume, up to 6 times, and their cross-shore elongation. The increase in disturbance induced by the notches had a significant impact on vegetation. New sandy bares were colonized by pioneer species leading to an increase in species richness and rejuvenation, in particular landward of the EENs. Although longer-term monitoring is required to draw conclusions, these results suggest that the excavation of foredune notches are able to re-establish an ecomorphological dynamic in the dunes of southwest France on the time scales of years, promoting landward sand transport and, thus, the foredune landward translation, while not threatening diversity. Such approach may become a relevant adaptation strategy to sea level rise and increased erosion in this region of the world.
(Science of the Total Environment. vol. 782, n° 0048-9697, pp. 146813, 21/06/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, ONF