Headland Rip Modelling at a Natural Beach under High-Energy Wave Conditions
A XBeach surfbeat model is used to explore the dynamics of natural headland rip circulation under a broad range of incident wave conditions and tide level. The model was calibrated and extensively validated against measurements collected in the vicinity of a 500-m rocky headland. Modelled bulk hydrodynamic quantities were in good agreement with measurements for two wave events during which deflection rips were captured. In particular, the model was able to reproduce the tidal modulation and very-low-frequency fluctuations (≈1 h period) of the deflection rip during the 4-m wave event. For that event, the synoptic flow behaviour shows the large spatial coverage of the rip which extended 1600 m offshore at low tide, when the surf zone limit extends beyond the headland tip. These results emphasize a deflection mechanism different from conceptualised deflection mechanisms based on the boundary length to surf zone width ratio. Further simulations indicate that the adjacent embayment is responsible for the seaward extent of the rip under energetic wave conditions. The present study shows that the circulation patterns along natural rugged coastlines are strongly controlled by the natural variability of the coastal morphology, including headland shape and adjacent embayments, which has implications on headland bypassing expressions.
(Journal of Marine Science and Engineering. vol. 9, n° 2077-1312, pp. 1161, 02/09/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
The role of physical disturbance for litter decomposition and nutrient cycling in coastal sand dunes
Disturbance increases ecosystem functioning in productive habitats but its effect in stressful conditions is less documented, although this is crucial for understanding the resilience of disturbed systems to natural and anthropogenic disturbances. Our goal is to assess the influence of physical disturbance for ecosystem functioning in coastal sand dunes. We set up an experimental design, including two treatments in four blocks, in a four km-long dune site from South West France. We simulated physical disturbance from marine and wind origin, digging Experimental Notches (EN), in the incipient (West EN treatment) and established foredunes (East EN treatment), respectively and compared the effects of EN to controls along transects including 13 positions from the beach to the transition dune behind ENs. We sampled litter decomposition rate, elevation variation, wind abrasion, sand grain size and vegetation composition. We also used drones to quantify sand deposition sheets during severe winter storms. Litter decomposition rate was the highest where sand accumulated the most, at the ecotone between the established foredune and transition dune and in the East EN treatment. This increase of ecosystem functioning was correlated to wind patterns. However, there was also a strong alongshore variability, with important sand deposition sheets occurring in some blocks depending on dune geomorphology. Vegetation composition was mainly influenced by shoreline distance, but also by the block and EN treatment, with a strong interaction between these three effects. We conclude that physical disturbance increase ecosystem functioning in the stressful conditions of the Atlantic sand dunes, only when sand accumulates, whereas excessive disturbances enhancing sand erosion are not favorable for ecosystem functioning.
(Ecological Engineering. vol. 162, n° 0925-8574, pp. 106181, 02/09/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, ONF
Contaminants of emerging concern in the Seine river basin: Overview of recent research
For over 30 years, the sources and the transfer dynamics of micropollutants have been investigated in the PIREN-Seine programme. Recent works included a wide range of chemicals and biological contaminants of emerging concern (i.e. contaminants whose occurrence, fate and impact are scarcely documented). This chapter presents a brief overview of research recently conducted on contaminants as diverse as macro- and microplastics, poly- and perfluoroalkyl substances (PFASs), pathogenic protozoa, antibiotics and the associated antibiotic resistance. The multiscalar study of plastics and PFASs at a large spatial scale is rare; the results produced in recent years on the Seine River catchment have provided an original contribution to the investigation of the dynamics of these contaminants in urban environments. The results also highlighted that pathogenic protozoa are ubiquitous in the Seine River basin and that the contamination of bivalves such as Dreissena polymorpha could reflect the ambient biological contamination of watercourses. The widespread occurrence of antibiotics in the Seine River was demonstrated, and it was shown that the resistome of biofilms in highly urbanised rivers constitutes a microenvironment where genetic support for antibiotic resistance (clinical integrons) and resistance genes for trace metals are concentrated.
(. vol. 90, pp. 355-380, 02/09/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LEESU, ENPC, UPEC UP12, M2C, UNICAEN, NU, INSU - CNRS, UNIROUEN, NU, CNRS, SEBIO, INERIS, URCA, ULH, NU, URCA, CNRS, GERS-LEE, METIS, EPHE, PSL, INSU - CNRS, SU, CNRS, SIAAP
Control Mechanisms of Primary Productivity Revealed by Calcareous Nannoplankton From Marine Isotope Stages 12 to 9 at the Shackleton Site (IODP Site U1385)
Nowadays, primary productivity variations at the SW Iberian Margin (IbM) are primarily controlled by wind-driven upwelling. Thus, major changes in atmospheric circulation and wind regimes between the Marine Isotope Stages (MIS) 12 and 9 could have driven substantial changes in phytoplankton productivity which remains poorly understood. We present a high-resolution calcareous nannofossil record from the Shackleton Site Integrated Ocean Discovery Program Site U1385 that allow the assessment of primary productivity and changing surface conditions on orbital and suborbital timescales over the SW IbM. These records are directly compared and integrated with terrestrial – Mediterranean forest pollen – and marine – benthic and planktic oxygen stable isotopes (δ18O), alkenone concentration [C37], Uk´37-Sea Surface Temperature and % C37:4 – proxy records from Site U1385. Our results indicate intra-interglacial increase in primary productivity together with intensification of the Azores anticyclonic high-pressure cell beyond the summer that suggests a two-phase upwelling behavior during the full interglacial MIS 11c (∼420–397 ka), potentially drived by atmospheric NAO-like variability. Primary productivity is largely enhanced during the inception of glacial MIS 10 and the early MIS 10 (∼392–356 ka), linked to intensified upwelling and associated processes during a period of strengthened atmospheric circulation. In agreement with the conditions observed during Heinrich events of the last glacial cycle, primary productivity reductions during abrupt cold episodes, including the Heinrich-type (Ht) events 4 to 1 (∼436, 392, 384 and 339 ka) and the Terminations V and IV, seems to be the result of halocline formation induced by meltwater arrival, reducing the regional upward nutrient transference.
(Paleoceanography and Paleoclimatology. vol. 36, n° 2572-4525, pp. e2021PA004246, 02/09/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, CCMAR, UAlg, IPMA, UNIBO, AU, UC Santa Cruz, UC
Geomorphology of a modern carbonate slope system and associated sedimentary processes: Example of the giant Great Abaco Canyon, Bahamas
The large acoustic data set acquired during the Carambar cruises is composed of high resolution bathymetry, backscatter data and very-high resolution seismic lines which allow for an overview of the morphology and sediment transfer processes from the shallow upper slope to the abyssal plain of a modern carbonate system: the north-eastern slope of the Little Bahama Bank. Surficial distribution of the acoustic facies and echofacies reflects a wide variety of sedimentary processes along and across the slope. The western sector of the Little Bahama Bank is dominated by depositional processes whereas its eastern sector, which is incised in the lower slope by giant canyons, is affected by erosion and bypass processes. Datasets suggest that currents play an important role both in along-slope sedimentary processes and in the abyssal plain. The Antilles Current appears to affect a large part of the middle and lower slopes. The absence of sizeable present-day channel/levee complexes or lobes at the mouth of the canyon - revealed by the bathymetric map - indicates that the southward flowing Deep Western Boundary Current influences modern abyssal sediment deposition. Based on depositional processes and indicators of canyon maturity observed in facies distribution, the current study proposes that differential subsidence affects the eastern versus western part of the bank. The morphology of the Great Abaco Canyon and Little Abaco Canyon, which extend parallel to the platform, and the Little Bahama Bank slope appears to be related to the Great Abaco Fracture Zone.
(Sedimentology. vol. 68, n° 0037-0746, pp. 266-293, 02/09/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Response of water-exchange capacity to human interventions in Jiaozhou Bay, China
Intensive anthropogenic activities, land reclamation, a cross-bay bridge construction, and the correction of Red Island have significantly changed the topography of Jiaozhou Bay (JZB) in northern China over the last decades. To quantify the effects of these modifications on the water-exchange capacity of the bay, the Finite Volume Community Ocean Model was used to calculate basin, regional and local residence time (RT) in the years 1935, 1966, 1986, 2000, 2008, and 2013, covering the periods of significant land reclamation. The bridge construction and a government plan to restore Red Island were also included in additional modelling scenarios. The regional RT increased significantly between 1935 and 1986, by 77% in the northeast, 40% in the west and 56% in the north-bridge regions, concurrent with the largest land reclamation. The regional RT continued to increase from 1986 to 2000 in the northeast and north-bridge regions but decreased slightly from 2000. These patterns can be explained by the general decreasing trend of the tidal prism from 1935 to 2000, up to 66% in the northeast region. A significant decrease in residual currents from 1935 to 1966 probably also contributed to explain this trend. The bridge construction had only a limited effect on regional RT. The restoration of Red Island would have reduced the regional RT in the northeast region from 83 to 60 days. The simulation of tracer transport, and therefore calculation of local RT, was found to be sensitive to the scheme used to formulate the horizontal diffusion coefficient, which should be taking into account when comparing results from different model configurations.
(Estuarine, Coastal and Shelf Science. vol. 249, n° 0272-7714, pp. 107088, 02/09/2026)
UNSW, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Fluorescence analysis allows to predict the oxidative capacity of humic quinones in dissolved organic matter: implication for pollutant degradation
Dissolved organic matter (DOM) controls the degradation and sequestration of aquatic pollutants and, in turn, water quality. In particular, pollutant degradation is performed by oxidant species that are generated by exposure of DOM to solar light, yet, since DOM is a very complex mixture of poorly known substances, the relationships between potential oxidant precursors in DOM and their oxydative capacity is poorly known. Here, we hypothesized that production of oxidant species could be predicted using fluorescence analysis. We analysed water samples from an alluvial plain by fluorescence spectroscopy; the three-dimensional spectra were then decomposed into seven individual components using a multi-way algorithm. Components include a protein-like fluorophore, e.g. tryptophan-like and tyrosine-like, three humic fluorophores, 2-naphthoxyacetic acid, and a by-product. We compared component levels with the ability of water samples to generate reactive species under solar light. The results show a strong correlation between reactive species production and the intensity of two humic-like fluorophores assigned to reduced quinones. Monitoring these fluorophores should thus allow to predict the ability of DOM degradation of pollutants in surface waters.
(Environmental Chemistry Letters. vol. 19, n° 1610-3653, pp. 1857-1863, 02/09/2026)
ICCF, SIGMA Clermont, INC-CNRS, UCA [2017-2020], CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, GEOLAB, UBP, IR SHS UNILIM, UNILIM, UCA [2017-2020], CNRS, UCA
Impact of Southern Ocean surface conditions on deep ocean circulation during the LGM: a model analysis
Changes in water mass distribution are considered to be a significant contributor to the atmospheric CO2 concentration drop to around 186 ppm recorded during the Last Glacial Maximum (LGM). Yet simulating a glacial Atlantic Meridional Overturning Circulation (AMOC) in agreement with paleotracer data remains a challenge, with most models from previous Paleoclimate Modelling Intercomparison Project (PMIP) phases showing a tendency to simulate a strong and deep North Atlantic Deep Water (NADW) instead of the shoaling inferred from proxy records of water mass distribution. Conversely, the simulated Antarctic Bottom Water (AABW) is often reduced compared to its pre-industrial volume, and the Atlantic Ocean stratification is underestimated with respect to paleoproxy data. Inadequate representation of surface conditions, driving deep convection around Antarctica, may explain inaccurately simulated bottom water properties in the Southern Ocean. We investigate here the impact of a range of surface conditions in the Southern Ocean in the iLOVECLIM model using nine simulations obtained with different LGM boundary conditions associated with the ice sheet reconstruction (e.g., changes of elevation, bathymetry, and land–sea mask) and/or modeling choices related to sea-ice export, formation of salty brines, and freshwater input. Based on model–data comparison of sea-surface temperatures and sea ice, we find that only simulations with a cold Southern Ocean and a quite extensive sea-ice cover show an improved agreement with proxy records of sea ice, despite systematic model biases in the seasonal and regional patterns. We then show that the only simulation which does not display a much deeper NADW is obtained by parameterizing the sinking of brines along Antarctica, a modeling choice reducing the open-ocean convection in the Southern Ocean. These results highlight the importance of the representation of convection processes, which have a large impact on the water mass properties, while the choice of boundary conditions appears secondary for the model resolution and variables considered in this study.
(Climate of the Past. vol. 17, n° 1814-9324, pp. 1139-1159, 02/09/2026)
CLIM, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, VU, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LOCEAN-PROTEO, LOCEAN, MNHN, IRD, INSU - CNRS, SU, CNRS, IPSL (FR_636), ENS-PSL, UVSQ, CEA, INSU - CNRS, X, CNES, SU, CNRS, UPCité
A review of the effects of contamination and temperature in Solea solea larvae. Modeling perspectives in the context of climate change
The flatfish species Solea solea has been the subject of research for supporting their management in fisheries, restocking natural populations, domestication in aquaculture, and ecotoxicology research. Soles undergo a metamorphosis with drastic morphological and physiological changes and settlement, processes that make them potentially more vulnerable to pollutants than other fish. Up to date, efforts made to develop its aquaculture production in Europe have been limited. In the context of climate change (CC), this review aims i) to gather research conducted in S. solea larvae that summarizes the effects of increased temperature and contaminant exposures during larval development; and ii) to provide a summarized and synergistic view about its larval development. The review consists of 4 sections. Section 1 justifies the selection of this species from ecological and economic perspectives. Section 2 focuses on larvae ontogenesis, metamorphosis, rearing challenges, and further aquaculture production. Section 3 reviews studies dealing with the effects of temperature change (due to CC) and pollutants on larval development. Finally, section 4 provides a "how to go forward on ecotoxicological research" guideline, in which we highlight the methods that we found promising as tools to study the combined effects of CC and pollution. The section includes a multidisciplinary framework that proposes how existing data coming from different scientific domains can be synthesized to be useful for risk assessors and ecotoxicologists. To benefit from such a framework, it is necessary to reach consensus and nurture team effort from players that operate in different research disciplines.
(Journal of Sea Research (JSR). vol. 176, n° 1385-1101, pp. 102101, 02/09/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LSEA MARBEC, UMR MARBEC, IRD, IFREMER, UM, CNRS, UMR MARBEC, IRD, IFREMER, UM, CNRS, GABI, INRAE, LEMAR, IRD, IFREMER, UBO EPE, CNRS
The Southern Ocean Radiolarian (SO-RAD) dataset: a new compilation of modern radiolarian census data
Abstract. Radiolarians (holoplanktonic protozoa) preserved in marine sediments are commonly used as palaeoclimate proxies for reconstructing past Southern Ocean environments. Generating reconstructions of past climate based on microfossil abundances, such as radiolarians, requires a spatially and environmentally comprehensive reference dataset of modern census counts. The Southern Ocean Radiolarian (SO-RAD) dataset includes census counts for 238 radiolarian taxa from 228 surface sediment samples located in the Atlantic, Indian, and southwest Pacific sectors of the Southern Ocean. This compilation is the largest radiolarian census dataset derived from surface sediment samples in the Southern Ocean. The SO-RAD dataset may be used as a reference dataset for palaeoceanographic reconstructions, or for studying modern radiolarian biogeography and species diversity. As well as describing the data collection and collation, we include recommendations and guidelines for cleaning and subsetting the data for users unfamiliar with the procedures typically used by the radiolarian community. The SO-RAD dataset is available to download from https://doi.org/10.1594/PANGAEA.929903 (Lawler et al., 2021).
(Earth System Science Data. vol. 13, n° 1866-3508, pp. 5441-5453, 02/09/2026)
RSES, ANU, HU, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS