Dynamics of low and high density microplastics in the world's largest choked coastal lagoon under contrasting meteoceanographic conditions
The contamination by plastic waste in aquatic environments has become a global issue, scientifically reported since 1970. The size and durability of microplastics (MPs, 1 μm > 5 mm) have made these debris widely distributed in aquatic environments. Despite various ongoing initiatives, there is a need to fill gaps in understanding how MPs are transported from their release sources to their final destinations. Therefore, understanding the distribution and dynamics of MPs in coastal areas, such as lagoons and estuaries, which are considered continental sources of MPs to the oceans, is essential to help fill these gaps and propose alternatives for managing what is the environmental problem of the century. In this context, this study aimed to assess the transport patterns of MPs in Patos Lagoon, the largest choked coastal lagoon in the world, considering contrasting meteoceanographic conditions in the system dynamics, such as wind and discharge. Using the hydrodynamic model TELEMAC-3D and the model for plastics particles TrackMPD, simulations were performed using a type of MP polymer (Polypropylene - PP). The simulations of MP transport considered advection, dispersion and the contribution of biofilm in increasing particle density (representing high-density microplastics). The results indicated a gradient of MPs retention from north to south, with higher concentrations of MPs occurring in the northern part of the system. The central region of the lagoon showed a greater tendency for MP export towards the southern region than retention. Meanwhile, the estuary region of Patos Lagoon exhibited a tendency for export of low-density MPs free of biofilm and retention of higher-density MPs, subject to the action of the Plastisphere. Additionally, based on the results obtained from density occurrence maps, it was possible to suggest potential accumulation areas of MPs throughout the lagoon system, reinforcing that the system can act as a sink in specific regions.
(Continental Shelf Research. vol. 285, n° 0278-4343, pp. 105396, 21/02/2026)
FURG, INRAE, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Reconstructing the Mid- to Late Holocene human-environments interactions in Cape Corsica (Corsica Island, Western Mediterranean) based on sedimentology, pollen analyses and geochemistry
This paper aims to reconstruct the interactions between human populations and their environment over the last 4500 years in Cape Corsica, a rocky peninsula situated on the northern edge of Corsica Island. During the Iron Age and Roman times, this region in the North Tyrrhenian Sea was at the crossroads of maritime trade routes, and was therefore recognized for its geostrategic position. However, little is known about its exact contribution in terms of natural resources exploitation and land use, nor regarding the general Late Holocene landscape evolution of the area. Three boreholes were drilled in three coastal lagoons situated on the eastern shore of Cape Corsica, at Biguglia, Meria and Macinaggio. To reconstruct the coastal landscape configuration together with vegetation history, land use and mineral extraction, laboratory work comprised granulometry, loss on ignition, pollen identification and elemental geochemistry. The chronostratigraphy is based on nine radiocarbon datings for all cores, and complementary 137Cs and 210Pb measurements were performed on the Meria core for recent chronology. For the northern edge of Cape Corsica, pollen results reveal that the highest human impacts on the vegetation composition were recorded during the Late Neolithic/Early Bronze Age, throughout Roman times, and in the Pisan-Genoese period, respectively. For all these periods, forest and maquis opening was observed to be coeval with cereal cultivation, thus revealing development of agriculture at the northern extremity of Cape Corsica. Conversely, the Middle to Final Bronze Age and pre-Christian era were characterized by a major recovery of the maquis and scarce evidence of land use. At Biguglia lagoon in the southern part of the peninsula, the vegetation composition for the last 1100 years reveals forest opening with moderate development of agriculture and, in the 10th Cent. CE., the connection between San Damiano Island and La Marana coastal barrier. In Cape Corsica, local contamination by mineral extraction (antimony in the form of stibine) is attested in the Meria valley during the known period of exploitation and also prior to this activity, possibly dating from the Genoese or the Corsican independence periods.
(Journal of Archaeological Science: Reports. vol. 62, n° 2352-409X, pp. 104985, 21/02/2026)
CEREGE, IRD, AMU, CdF (institution), INSU - CNRS, CNRS, INRAE, IPHES-CERCA, URV, ULiège, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Record of trace organic contaminants in a river sediment core: A fingerprint of regulatory changes?
This study reconstructs the historical deposition of 76 trace organic contaminants (TrOCs), comprising pharmaceuticals, pesticides, and per-and polyfluoroalkyl substances (PFAS), in a dated sediment core taken from a secondary channel of the Seine River downstream of the Paris conurbation. Sediment chronology, established through $^{210}$Pb and $^{137}$Cs radionuclide depth activities, spans the period from 1943 to 2022, providing a long-term record of anthropogenic influence on fluvial contamination. The vertical profiles of pharmaceutical residues reveal temporal patterns closely aligned with their respective dates of market introduction, followed by increasing concentrations and subsequent declines. Maximum TrOC sedimentary concentrations were observed during the 1980s, coinciding with incomplete wastewater collection coverage. A sharp decrease in concentrations post-2000 reflects significant improvements in wastewater collection and treatment infrastructure. For pesticides, sedimentary trends also correlate with usage history and regulatory actions, with detectable declines frequently preceding official bans, suggesting the influence of progressive restrictions or shifts in agricultural practices. In contrast, PFAS profiles display more complex dynamics: legacy compounds such as perfluorooctanesulfonic acid and its precursors peaked in the early 2000s, after which their decline was offset by the increasing presence of alternative substances (e.g., fluorotelomersulfonic acids, betaines), indicative of industrial substitution. Overall, sediment composition had a secondary influence on TrOC profiles, with external factors such as regulatory decisions and technological developments in wastewater treatment playing predominant roles. These findings underscore the utility of collecting and analyzing sedimentary archives for assessing the long-term effectiveness of environmental policies and for identifying persistent and emerging contaminants in riverine systems.
(Journal of Environmental Management. vol. 389, n° 0301-4797, pp. 126276, 21/02/2026)
METIS, EPHE, PSL, INSU - CNRS, SU, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, GEDI, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, LEHNA, UCBL, ENTPE, 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.
(21/02/2026)
Info&Sols, INRAE, LPTC, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Quantitative measurement of benthic foraminifera sediment reworking using a three-dimensional sensor
Despite their worldwide distribution and very high densities, the contribution of benthic meiofaunal species to sediment reworking has largely been neglected in bioturbation research. This is partly due to the challenge in obtaining reliable measurements of these minute size organisms. So far, only a handful of studies have investigated the influence of these microbioturbators on particle transport processes at the sediment surface. These studies most often used the surface image analysis (SIA) method, which indirectly estimates surface sediment reworking rate (SSRR) by tracking the position of individuals at the sediment surface over time. Here, focusing on benthic foraminifera, we demonstrate that successive assessments of sediment microtopography mapping using a three-dimensional (3D) sensor can provide direct and accurate quantifications of meiofaunal SSRR, with high spatial and temporal resolutions. This new method is thus particularly suitable to investigating the as-yet-unknown influence of the meiobenthic fauna, such as foraminifera, on particle transport at the sediment–water interface and more generally on the functioning of benthic soft-bottom ecosystems.
(Journal of Micropalaeontology. vol. 44, n° 0262-821X, pp. 401-413, 21/02/2026)
LOG, INSU - CNRS, ULCO, CNRS, IRD [Ile-de-France], EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Simple physics-based rip current and shore-break wave hazard predictors for beaches in southwest
Sandy beaches are attractive yet potentially dangerous environments due to physical hazards in the surf zone. The most severe natural hazards are rip currents and shore-break waves, which form under varying wave, tide, and morphological conditions. This study introduces two simple, physics-based models to forecast channel rip current flow speed V and shore-break wave energy Esb. These models were applied to La Lette Blanche, a high-energy meso-macro-tidal beach in southwest France, where both hazards coexist. Lifeguard-perceived hazard data collected hourly from July to August 2022 during patrol hours (11 AM–7 PM) were used to calibrate the models. This data also informed a 5-level hazard scale, from 0 (no hazard) to 4 (maximum hazard). The models accurately predict hazard levels, accounting for tidal and wave influences. Requiring only basic beach morphology metrics, this approach offers a promising tool for forecasting surf-zone hazards on beaches with minimal morphological data and available wave forecasts.
(21/02/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UR ETTIS, INRAE, UR EABX, INRAE
Modification des régimes de sédimentation en rade de Brest en réponse aux pressions climatiques et humaines
(21/02/2026)
LUSAC, UNICAEN, NU, INTECHMER, Cnam, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
History of the sedimentary regimes of the Aquitaine margin (Bay of Biscay, France) at the outlet of its main tributaries during the last millennium: a mirror of the North Atlantic and European climates
The present work is based on the analysis of two hemipelagic sequences collected off the two main fluvial tributaries that enter the southern Bay of Biscay along the Aquitaine margin: the Gironde estuary, for core JB7-ST3c retrieved from the West-Gironde mud patch; and the Adour river, for core MD03–2693 retrieved from the Capbreton canyon meanders. Their positioning, at the northern and southern edges of the Aquitaine shelf, not only allows us to obtain a synoptic view of the southern Bay of Biscay past oceanography, but, over the last thousand years covered by these archives, also provides access to key contextual elements related to local as well as global hydroclimatic forcings. This article focuses on the interpretation of the sedimentological signal based on key X-ray fluorescence (XRF) elemental profiles obtained along the cores, within the framework of coherent age models newly built for the two sequences. The consistency of the two records allows us to robustly relate the evolution of the XRF profiles to the hydroclimatic regime of the Bay of Biscay, and to compile and discuss a chronicle of the environmental events that have marked the sites. This is achieved through a regional scale analysis, encompassing synchronous occurrences on the proximate continent, complemented by a broader synoptic perspective within the context of the well-documented European and North Atlantic historical frames. This chronicle is pivotal in comprehending the correlation between continental and oceanic regimes along the Euro-Atlantic margin, in addition to their links to the climatic processes that govern the Northern Hemisphere region. Our results clearly discriminate specific climatic trends, highlighting the Medieval Warm Period, the Little Ice Age and the Current Warm Period as contrasted intervals. The climatic patterns identified during these specific phases are discussed in the light of recent advances in our knowledge of their modes of variability, and raise the question of teleconnections between the North Atlantic Oscillation, Atlantic sea-surface conditions and dynamics, together with atmospheric ones and especially storminess over Europe.
(Global and Planetary Change. vol. 255, n° 0921-8181, pp. 105039, 21/02/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Hourly valve opening data of oysters Crassostrea gigas measured during a one-year semi-controlled experiment
This dataset shows the hourly valve behavioral data of the 32 oysters Crassostrea gigas throughout the year of the experiment as well as the temperature recorded by each HFNI valvometer. The oyster valve behavior is characterized by 3 parameters: the Valve Opening Amplitude (VOA, the percentage of the valve opening relative to maximum opening), the Valve Opening Duration (VOD, the percentage of time that an oyster spends with its valves open), and the VOA/VOD. For each parameter, the data are presented for each oyster and as a group average for each condition. Missing data correspond to the death of oysters or the stopping of recording by a HFNI valvometer.
(21/02/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Hourly valve opening data of oysters Ostrea edulis measured during a one-year semi-controlled experiment
This dataset shows the hourly valve behavioral data of the 32 oysters Ostrea edulis throughout the year of the experiment as well as the temperature recorded by each HFNI valvometer. The oyster valve behavior is characterized by 3 parameters: the Valve Opening Amplitude (VOA, the percentage of the valve opening relative to maximum opening), the Valve Opening Duration (VOD, the percentage of time that an oyster spends with its valves open), and the VOA/VOD. For each parameter, the data are presented for each oyster and as a group average for each condition. Missing data correspond to the death of oysters or the stopping of recording by a HFNI valvometer.
(21/02/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS