Holocene subsurface temperature variability in the eastern Antarctic continental margin
We reconstructed subsurface ($45-200 m water depth) temperature variability in the eastern Antarctic continental margin during the late Holocene, using an archaeal lipid-based temperature proxy (TEX 86 L). Our results reveal that subsurface temperature changes were probably positively coupled to the variability of warmer, nutrient-rich Modified Circumpolar Deep Water (MCDW, deep water of the Antarctic circumpolar current) intrusion onto the continental shelf. The TEX 86 L record, in combination with previously published climatic records, indicates that this coupling was probably related to the thermohaline circulation, seasonal variability in sea ice extent, sea temperature, and wind associated with high frequency climate dynamics at low-latitudes such as internal El Niño Southern Oscillation (ENSO). This in turn suggests a linkage between centennial ENSO-like variability at low-latitudes and intrusion variability of MCDW into the eastern Antarctic continental shelf, which might have further impact on ice sheet evolution.
(Geophysical Research Letters. vol. 39, n° 0094-8276, pp. L06705, 28/10/2026)
NIOZ, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, AWI, VU, NIOZ
Recovery potential of periphytic biofilms translocated in artificial streams after industrial contamination (Cd and Zn)
Metal wastes can significantly disturb aquatic communities, particularly photosynthetic organisms, the main primary producers in freshwater running ecosystems. In this study, biofilms and diatoms were used as bioindicators to characterize the kinetics of biofilm recovery. An experimental decontamination study was conducted under laboratory conditions, after biofilm colonisation at a site subject to discharge of industrial metals (Zn and Cd) and in parallel at an upstream site, metal-free, considered as a control. After 24 days of colonisation, biofilms were translocated and maintained in the laboratory for 56 days under clean conditions (control and decontamination) or metal contamination. Various tests were conducted from the community level—measures of metal bioaccumulation, cell densities and taxonomic investigations, to the individual level—measures of teratological forms. After 56 days of decontamination, Zn and Cd concentrations in decontaminated biofilms showed a sharp decline, respectively ranging from 6.7 ± 2 to 4 ± 2.5 mg Zn g-1 DW and from 207.6 ± 24.5 to 45.4 ± 9.9 lg Cd g-1 DW. However, at the end of the experiment bioaccumulations remained significantly higher than concentrations in control biofilms. Despite a diatom evolution in biofilm assemblages, taxonomic inventories did not demonstrate a complete restoration of diatom communities in biofilms under decontamination conditions compared with controls, since metal-resistant species initially present after colonisation at the contaminated site, such as Eolimna minima, persisted in high abundance in decontaminated biofilms. Biofilms kept under metal pressure showed very high bioaccumulation capacities and a sharp decline of species diversity which allowed identification of some resistant species. Regarding these first results on the behaviour of diatom biofilms under experimental decontamination conditions, improvement of the natural hydrosystem’s chemical state appears quickly, but an eventual return to good ecological status appears delayed, with the persistence of metal-tolerant species even after 56 days.
(Ecotoxicology. vol. 21, n° 0963-9292, pp. 1403-1414, 28/10/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, CNRS, UR REBX, IRSTEA
Increase of marine juvenile fish abundances in the middle Gironde estuary related to warmer and more saline waters, due to global changes
Estuaries have an essential ecological function for several marine fish species, that use these systems as nurseries. Previous studies in the Gironde estuary have reported an increase in water temperature and an extended seawater intrusion associated to global changes. In this study, we evaluated whether these changes impact the nursery function in the middle part of the system, based on the analyses of long-term data series (1991e2009) collected in that area. Trend analysis, correlations and generalized additive models (GAM) were computed in order to study the influence of water temperature and salinity changes on marine juveniles occurrence/densities. Results showed that densities of all the studied species (i.e. Engraulis encrasicolus, Sprattus sprattus, Dicentrarchus labrax, Solea solea, Argyrosomus regius, Merlangius merlangus) significantly increased over the period considered. Changes in water temperature and seawater intrusion contributed to explain the variability in presence/absence and in densities of the majority of these species. However, the deviance explained by GAM and the relevance of these two explanatory variables differed considerably according to species. For most species, it was suggested that the interaction of these two factors, and their effects on other variables, may explain the increase in abundance in the middle part of the Gironde. The effects of global changes in this estuarine system may favour its nursery function for marine juveniles, but some evidence of effects at a wider scale (community and ecosystem levels) may alter the structure and functioning of this system.
(Estuarine, Coastal and Shelf Science. vol. 104-105, n° 0272-7714, pp. 46-53, 28/10/2026)
UR EPBX, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, ULISBOA
Monitoring and indicators in port. Development of HFNI Valvometry for the online assessment of ecological potential. Portonovo : present and future of port water quality management in the EU Atlantic Area
(28/10/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LMBA, UBS, UBO EPE, CNRS
Mass wasting processes along the Owen Ridge (Northwest Indian Ocean)
The Owen Ridge is a prominent relief that runs parallel to the coast of Oman in the NW Indian Ocean and is closely linked to the Owen Fracture Zone, an 800-km- long active fault system that accommodates today the Arabia-India strike-slip motion. Several types of mass failures mobilizing the pelagic cover have been mapped in details along the ridge using multibeam bathymetry and sediment echosounder. Here we present a synthetic map of the different types of mass wasting features observed along the ridge and we further establish a morphometric analysis of submarine landslides. The spatial variation of failure morphology is strongly related to the topography of the basement. The highest volumes of multi-events generated slides are mobilized along the southern portion of the ridge. There, the estimated volume of evacuated material during a slide is up to 45 km3. Combining these new observations with re-interpreted ODP seismic lines (Leg 117) documents sporadic mass wasting events through time along the southern segment of the ridge since its uplift in the Early Miocene, with a typical recurrence rate of the order of 105-106 years. Although seismicity may still be the final triggering process, mass wasting frequency is mainly controlled by the slow pelagic sedimentation rates and hence, time needed to build up the 40-80 m thick pelagic cover required to return to a mechanically unstable pelagic cover .
(Marine Geology, n° 0025-3227, pp. 1-21, 28/10/2026)
iSTeP, UPMC, CNRS, LGENS, INSU - CNRS, CNRS, ENS-PSL, PSL, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
A new breaking wave height direct estimator from video imagery
Breaker height is a key parameter of nearshore processes and the demand for a continuous remote estimator is pressing. In this paper we present a standalone remote video-based method that estimates wave height at the breakpoint. Individual breaking events are first identified from changes in optical properties and wave height is further derived from the optical signature at the onset of breaking. An extended validation is performed using a dense wave basin dataset. The results show the ability of the method to measure individual breaker heights (9% of mean error, 18% RMS). In addition, the unique combination of in situ and remotely sensed data allows the estimation of two other breaking-related parameters, the height-to-depth ratio and wave front face slope, which show a substantial amount of dispersion. Because nearshore video systems are rapidly spreading over world coasts, this low-cost remote breaker height estimator should encounter large interest in coastal engineering studies.
(Coastal Engineering. vol. 61, n° 0378-3839, pp. 42-48, 28/10/2026)
PUC, LEGOS, IRD, UT3, Comue de Toulouse, INSU - CNRS, CNES, CNRS, UTFSM, LEGI, UJF, Grenoble INP, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Probabilités des évènements rares sur des séries temporelles environnementales
(28/10/2026)
LMBA, UBS, UBO EPE, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LIMATB, UBS, UBO EPE, IBNM, UBO EPE
Comparison of kernel density estimators with assumption on number of modes
(28/10/2026)
LMBA, UBS, UBO EPE, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, CQFD, IMB, UB, Bordeaux INP, CNRS, Inria, IMB, UB, Bordeaux INP, CNRS
Spatial and long-term changes in the functional and structural phytoplankton communities along the French Atlantic coast
Spatial and interannual variations of phytoplankton diversity were characterized along the French Atlantic Coast in relation to physical factors and large-scale climatic indices using phytoplankton surveys conducted from 1993 to 2010 in four geographical areas. This study relates phytoplankton diversity to oyster recruitment success by comparing a 'specific' versus a 'functional' diversity approach. Functional diversity was represented by functional groups of different phytoplanktonic functional traits (size, shape, toxicity), relevant for oyster feeding during growth, reproduction and larval development. Phytoplankton diversity patterns along the French Atlantic coast corresponded to a geographical distribution mainly driven by a latitudinal gradient and hydrodynamic features as confirmed by the functional characteristics of the indicator species recorded for each geographical area (C-S-R strategies of Reynolds, specific habitat). This geographical typology was less clear for functional diversity. Only few functional groups were explained by physical factors: the non-toxic small and solitary cells were in particular related to temperature, with high densities observed in the southern areas. Even if temporal variation was less important in explaining the phytoplankton diversity patterns, the main drivers explaining the interannual pattern were the large-scale climatic indices, mainly the Atlantic Multidecennal Oscillation. Functional groups were readily explained by climatic indices than species even if the relationships cannot be applied generally because of the non-linearity of the correlations (local and temporal variations). However, the potentially toxic, small and linear phytoplankton were anticorrelated to NAO. The functional approach thus brings constructive elements concerning the relationships between the prey assemblage of oysters and their physical drivers. Redundancy and co-inertia analyses appeared as complementary analyses in investigating phytoplankton pattern of variation, being particularly useful in analyzing geographical and temporal diversity fluctuation, respectively. © 2012.
(Estuarine, Coastal and Shelf Science. vol. 108, n° 0272-7714, pp. 37--51, 28/10/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, IFREMER, LIENSs, INSU - CNRS, ULR, CNRS, DYNECO, IFREMER, BOREA, UNICAEN, NU, MNHN, IRD, SU, CNRS, UA, CNRS, UNICAEN, NU, NU
Tracking atmospheric and riverine terrigenous supplies variability during the last glacial and the Holocene in central Mediterranean
The objectives were to retrace the eolian and fluvial terrigenous supplies in a sediment core from the Sicilian-Tunisian Strait by coupling mineralogical, grain-size and geochemical approaches, in order to get informations on the atmospheric versus riverine 5 contributions to sedimentation on the southern side of central Mediterranean since the last glacial. The eolian supply is dominant over the whole interval, excepted during the sapropel S1 when riverine contribution apparently became significant, and particles provenance has been modified since Last Glacial. Saharan contribution increased during the Bølling-Allerød, evidencing the persistence of aridity over North Africa although the northern Mediterranean already experienced moister and warmer conditions. The Younger Dryas is marked by proximal dust inputs highlighting intense regional eolian activity. A southward migration of dust provenance toward Sahel occurred at the onset of the Holocene, likely resulting from a southward position of the Inter Tropical Convergence Zone, probably associated with a large-scale atmospheric reorganization. Finally, a peculiar high terrigenous flux associated with drastic modifications of the mineralogical and geochemical sediment signature occurred during the sapropel S1, suggesting the propagation of fine-particles derived from major floodings of the Nile River – resulting from enhanced rainfall on northeastern Africa – and their transportation across the Sicilian-Tunisian Strait by intermediate water-masses.
(pp. 2921–2968, 28/10/2026)
LOG, INSU - CNRS, ULCO, CNRS, IRD [Ile-de-France], LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, GEOPS, UP11, CNRS