Climate Change and Risks for the Coastline: Scientific Contributions for a Sustainable and Just Adaptation
This contribution aims to be a summary and a presentation of knowledge from research conducted by the laboratories of Nouvelle-Aquitaine on the physical risks of coastal areas, their developments as a result of climate change and socio-economic and political dynamics at work with regard to the measures and strategies for adaptation. It is the result of collaboration between approximately 30 researchers from the following laboratories: BRGM, Criham (Université de Poitiers), EPOC (UMR Université de Bordeaux - CNRS), ETBX (Irstea), GREThA (UMR Université de Bordeaux - CNRS), LIENSs (UMR Université de La Rochelle - CNRS), ONF, SIAME (Université de Pau et des Pays de l'Adour).
(pp. 36, 20/06/2026)
UR ETBX, IRSTEA, BRGM, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LIENSs, INSU - CNRS, ULR, CNRS
Microplastics FTIR characterisation and distribution in the water column and digestive tracts of small pelagic fish in the Gulf of Lions
(Marine Pollution Bulletin. vol. 142, n° 0025-326X, pp. 510--519, 20/06/2026)
UMR MARBEC, IRD, IFREMER, UM, CNRS, UM, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
A Late Quaternary record of highstand shedding from an isolated carbonate platform (Juan de Nova, southern Indian Ocean)
A 27 m core collected on the sea floor near Juan de Nova island at 1,909 m depth in the SW Indian Ocean preserves a high-resolution record of carbonate sediment export to the deep sea over the past 1 Myr. Core chronology was established using calcareous nannofossil biostratigraphy and benthic foraminiferal δ 18 O. Throughout the core, preserved highstand intervals (MIS 1, 5, 7, 9, 11, 13, 15, 23 and 25) are marked by an increase in the aragonite content within the sediment. Aragonite is likely sourced from the nearby Juan de Nova carbonate platform ca 10 km to the south, and is interpreted as resulting from flooding of the platform top. Platform inundation allows carbonate muds to be winnowed from their original shallow-water environment of deposition, suspended in the water column, and redeposited onto the proximal slopes and within the basin. Sharp increases in aragonite content at the beginning of each highstand interval can be used to estimate the approximate sea-level range when platform flooding occurred; results show that the depth of the platform top has likely changed little over the past 1 Myr due to balanced aggradation and subsidence. Previously hypothesized large-scale aragonite dissolution cycles are evidenced by a disproportionally low aragonite increase during MIS 11. This study provides a new, exceptionally long record of highstand shedding, expanding the known occurrences of the process to the southern Indian Ocean and supporting its importance as a globally significant depositional mechanism that impacts deep-sea stratigraphic records.
(Depositional Record. vol. 5, n° 2055-4877, pp. 540-557, 20/06/2026)
UCD, GM, IFREMER, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LGO, UBS, IFREMER, UBO EPE, CNRS
Adverse effects induced by chronic gamma irradiation in progeny of adult fish not affecting parental reproductive performance
Multigenerational studies became of great interest in ecotoxicology since the consequence of parental exposure on offspring generations has been established in situ or in laboratory conditions. This study mainly examined chronic effects of external Cs-137 gamma irradiation exposure at 4 dose rates (control, 0.5, 5 and 50 mGy h-1) on adult zebrafish (F0) exposed for 10 days and its progeny (F1) exposed for 4 days. The main investigated endpoints included parental reproductive performance, embryo-larval survival, DNA alterations and ROS production in F0 and F1. No effects on reproductive success, fecundity or egg fertilization rate were observed. However, drastic effects were observed on F1 at the highest dose rate, resulting in a mortality of 100%. The drastic effects were also observed when the progeny was not irradiated. We demonstrate that the sensitivity of the embryos was mainly due to parental irradiation. Moreover, these drastic effects induced by adult irradiation disappeared over time when 10 d- irradiated adults were placed in a non-irradiated condition. DNA alterations in larvae were observed for the three dose rates, with an increase of ROS production was also shown for the two lowest dose rates. This study improves our understanding of the consequences of multigenerational exposure conditions. Furthermore, it incentivizes us to take into account transmitted generational effects in ecological risk assessments.
(Environmental Toxicology and Chemistry. vol. 38, n° 0730-7268, pp. 2556-2567, 20/06/2026)
IRSN/PSE-ENV/SRTE/LECO, IRSN/PSE-ENV/SRTE, IRSN, IRSN/PSE-SANTE/SDOS/LMDN, IRSN/PSE-SANTE/SDOS, IRSN, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Ocean temperature impact on ice shelf extent in the eastern Antarctic Peninsula
The recent thinning and retreat of Antarctic ice shelves has been attributed to both atmosphere and ocean warming. However, the lack of continuous, multi-year direct observations as well as limitations of climate and ice shelf models prevent a precise assessment on how the ocean forcing affects the fluctuations of a grounded and floating ice cap. Here we show that a +0.3–1.5 °C increase in subsurface ocean temperature (50–400 m) in the northeastern Antarctic Peninsula has driven to major collapse and recession of the regional ice shelf during both the instrumental period and the last 9000 years. Our projections following the representative concentration pathway 8.5 emission scenario from the Fifth Assessment Report of the Intergovernmental Panel on Climate Change reveal a +0.3 °C subsurface ocean temperature warming within the coming decades that will undoubtedly accelerate ice shelf melting, including the southernmost sector of the eastern Antarctic Peninsula.
(Nature Communications. vol. 10, n° 2041-1723, pp. 304, 20/06/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, IACT, CSIC, UGR, AWI, UABC, LOCEAN-VOG, LOCEAN, MNHN, IRD, INSU - CNRS, SU, CNRS, IPSL (FR_636), ENS-PSL, UVSQ, CEA, INSU - CNRS, X, CNES, SU, CNRS, UPCité, NIOZ, UCL-ASTR, UCLouvain, ULaval, INSU - CNRS, CNRS, KOPRI
Environmental controls on surf zone injuries on high-energy beaches
The two primary causes of surf zone injuries (SZIs) worldwide, including fatal drowning and severe spinal injuries, are rip currents (rips) and shore-break waves. SZIs also result from surfing and bodyboarding activity. In this paper we address the primary environmental controls on SZIs along the high-energy meso-macro-tidal surf beach coast of southwestern France. A total of 2523 SZIs recorded by lifeguards over 186 sample days during the summers of 2007, 2009 and 2015 were combined with measured and/or hindcast weather, wave, tide, and beach morphology data. All SZIs occurred disproportionately on warm sunny days with low wind, likely because of increased beachgoer numbers and hazard exposure. Relationships were strongest for shore-break- and rip-related SZIs and weakest for surfingrelated SZIs, the latter being also unaffected by tidal stage or range. Therefore, the analysis focused on bathers. More shore-break-related SZIs occur during shore-normal incident waves with average to below-average wave height (significant wave height, Hs = 0.75-1.5 m) and around higher water levels and large tide ranges when waves break on the steepest section of the beach. In contrast, more rip-related drownings occur near neap low tide, coinciding with maximised channel rip flow activity, under shore-normal incident waves with Hs > 1.25 m and mean wave periods longer than 5 s. Addi- tional drowning incidents occurred at spring high tide, presumably due to small-scale swash rips. The composite wave and tide parameters proposed by Scott et al. (2014) are key controlling factors determining SZI occurrence, although the risk ranges are not necessarily transferable to all sites. Summer beach and surf zone morphology is interannually highly variable, which is critical to SZI patterns. The upper beach slope can vary from 0.06 to 0.18 between summers, resulting in low and high shore-break-related SZIs, respectively. Summers with coast-wide highly (weakly) developed rip channels also result in widespread (scarce) rip-related drowning incidents. With life risk defined in terms of the number of people exposed to life threatening hazards at a beach, the ability of morphodynamic models to simulate primary beach morphology characteristics a few weeks or months in advance is therefore of paramount importance for predicting the primary surf zone life risks along this coast.
(Natural Hazards and Earth System Sciences. vol. 19, n° 1561-8633, pp. 2183-2205, 20/06/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, SBMS, BRGM, UB, CHU Bordeaux, BPH, UB, INSERM
Effects of Improved 17 O Correction on Interlaboratory Agreement in Clumped Isotope Calibrations, Estimates of Mineral‐Specific Offsets, and Temperature Dependence of Acid Digestion Fractionation
The clumped isotopic composition of carbonate‐derived CO2 (denoted Δ47) is a function of carbonate formation temperature and in natural samples can act as a recorder of paleoclimate, burial, or diagenetic conditions. The absolute abundance of heavy isotopes in the universal standards VPDB and VSMOW (defined by four parameters: R13VPDB, R17VSMOW, R18VSMOW, and λ) impact calculated Δ47 values. Here, we investigate whether use of updated and more accurate values for these parameters can remove observed interlaboratory differences in the measured T‐Δ47 relationship. Using the updated parameters, we reprocess 14 published calibration data sets measured in 11 different laboratories, representing many mineralogies, bulk compositions, sample types, reaction temperatures, and sample preparation and analysis methods. Exploiting this large composite data set (n = 1,253 sample replicates), we investigate the possibility for a “universal” clumped isotope calibration. We find that applying updated parameters improves the T‐Δ47 relationship (reduces residuals) within most labs and improves overall agreement but does not eliminate all interlaboratory differences. We reaffirm earlier findings that different mineralogies do not require different calibration equations and that cleaning procedures, method of pressure baseline correction, and mass spectrometer type do not affect interlaboratory agreement. We also present new estimates of the temperature dependence of the acid digestion fractionation for Δ47 (Δ*25‐X), based on combining reprocessed data from four studies, and new theoretical equilibrium values to be used in calculation of the empirical transfer function. Overall, we have ruled out a number of possible causes of interlaboratory disagreement in the T‐Δ47 relationship, but many more remain to be investigated.
(Geochemistry, Geophysics, Geosystems. vol. 20, pp. 3495 - 3519, 20/06/2026)
PALEOCEAN, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, IUP, IPGP, INSU - CNRS, UPD7, UR, IPG Paris, CNRS, UF, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, CALTECH
Tellurium behaviour in a major European fluvial–estuarine system (Gironde, France): fluxes, solid/liquid partitioning and bioaccumulation in wild oysters
The environmental behaviour of tellurium is poorly understood. We investigate the transport of tellurium in both dissolved and particulate forms from the river watershed to the Gironde Estuary, where a 30-year historical record provides insight on tellurium bioaccumulation in wild oysters. These results constitute the first comprehensive study on natural tellurium behaviour in a major fluvial-estuarine system, information essential for predictive modelling of tellurium risk assessment. AbstractTellurium (Te) is a technology critical element (TCE) with largely unknown environmental behaviour, especially in continent-ocean interface systems. The unknown behaviour results from the lack of studies in aquatic environments and from analytical challenges limiting the determination of its naturally low (ultra-trace) environmental levels. We performed a comprehensive study of Te in the Lot–Garonne–Gironde fluvial–estuarine system to better understand seasonal variations, solid/liquid partitioning (Kd), gross fluxes, estuarine dynamics, and transfer to wild oysters at the estuary mouth. A temporal record (2014–2017) of dissolved (Ted) and particulate (Tep) Te concentrations at five sites in the Lot–Garonne River system shows little differences between sites, with average ~0.9ngL−1 and ~50µgkg−1 respective concentrations. Watershed Ted and Tep follow parallel seasonal patterns, which result in constant partitioning (log10 Kd ~4.75Lkg−1), with constant annual gross dissolved fluxes (~15.0kgy−1) and variable gross particulate fluxes (from 6.50 to 140kgy−1) entering the Gironde Estuary. Estuarine reactivity in contrasting hydrological conditions (from flood to drought) suggest that grain-size effects and/or estuarine hydrological residence times strongly affect Tep behaviour. Historical records (1984–2017) of Te in wild oysters at the estuary mouth vary from 1.33 to 2.89µgkg−1 dry weight (d.w.), without any clear long-term trend. This study provides rare knowledge on Te environmental dynamics in aquatic systems, and suggests that, although no current anthropogenic sources were identified in the economically developed Lot-Garonne-Gironde fluvial-estuarine system, there is a non-negligible bioaccumulation in wild oysters at the estuary mouth.
(Environmental Chemistry. vol. 16, n° 1448-2517, pp. 229, 20/06/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Introduction: Special Issue on Coastal Evolution under Climate Change along the Tropical Overseas and Temperate Metropolitan France
This paper presents how major French science-oriented public institutions and Ministry of Higher Education, Research, and Innovation (MESRI) have developed and structured coastal observatories along metropolitan and oversea coastlines in order to better understand the metropolitan and oversea French coastal evolution on a wide range of temporal and spatial scales. Scientific results presented in this special Issue have been obtained in the framework of the resulting DYNALIT / ILICO observatory network.
(Journal of Coastal Research. vol. 88, n° 0749-0208, pp. 1-2, 20/06/2026)
IFREMER, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Dispersive and dispersive-like bores in channels with sloping banks
In this paper, a detailed analysis of undular bore dynamics in channels of variable cross-section is presented. Two undular bore regimes, Low Froude Number (LFN) and High Froude Number (HFN), are simulated with a Serre-Green-Naghdi model, and the results are compared with the experiments by Treske. We show that contrary to Favre waves and HFN bores, which are controlled by dispersive non-hydrostatic mechanisms, LFN bores correspond to a hydrostatic phenomenon. The dispersive-like properties of the LFN bores is related to wave refraction on the banks in a way similar to that of edge waves in the nearshore. A fully hydrostatic asymptotic model for these dispersive-like bores is derived and compared to the observations, confirming our claim
(Journal of Fluid Mechanics. vol. 870, n° 0022-1120, pp. 595-616, 20/06/2026)
UGA [2016-2019], IRSTEA, UR ETGR (ETNA), IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, CARDAMOM, IMB, UB, Bordeaux INP, CNRS, Inria