Canyon Heads and River Plumes: How Might They Influence Neritic Planktonic Foraminifera Communities In The SE Bay of Biscay?
The present study discusses the distribution of living planktonic foraminifera (LPF) in a neritic environment from the SE Bay of Biscay. Four sites, located at the head of Capbreton Canyon and near the Adour River mouth, were sampled during four cruises between June 2006 and July 2008. Each site was sampled with a plankton net (>100 μm) to characterize the LPF communities. The four onshore stations are here compared to three offshore stations located along a bathymetric transect on the Plateau des Landes to document the influence of submarine canyon bathymetry and river input on LPF communities. Five major species were observed: Globigerina bulloides, Globigerinella calida-G. bulloides complex, Neogloboquadrina pachyderma dextral, Globorotalia inflata, and Turborotalita quinqueloba. Late spring (mid-June 2006) standing stocks showed a decreasing trend toward the coast, whereas fall (late November 2007) and summer (mid-July 2008) standing stocks showed higher values at the canyon head and onshore stations. High standing stocks dominated by specimens from the G. calida-G. bulloides complex were recovered in late November 2007 at neritic stations and could be related to upwelling and/or strong tidal currents in the submarine Capbreton Canyon. Their distribution and production in the SE Bay of Biscay is affected by the Adour River turbidity discharge and also by mesoscale upwelling events induced around the Capbreton Canyon head.
(Journal of Foraminiferal Research. vol. 42, n° 0096-1191, pp. 257 - 269, 13/04/2026)
BIAF, UA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LPG-ANGERS, LPG, UA, UN UFR ST, UN, INSU - CNRS, 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, 13/04/2026)
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
Evaluation of advanced oxidation processes for the reduction of refractory micropollutants in treated wastewater
Complementary treatments can allow a reduction of concentrations of micropollutants to reach values compatible with a good state of the environment. Processes that seem more efficient to eliminate refractory substances from treated wastewater are advanced technologies similar to the ones used for drinking water production : ozonation, UV light, adsorption on activated carbon, membranes and advanced oxidation processes. Advanced oxidation processes (AOP) rely on the formation of HO° radical witch is less selective than ozone and has higher reaction constants. An advanced oxidation processes pilot was tested in two plants. The AOP pilot is a container with two reactors in parallel (O3/H2O2 and O3/H2O2/UV). Mass balances were performed based on wastewater flow and micropollutants concentration data at the inlet and at the outlet of the studied processes. All advanced oxidation processes tested were efficient on beta blockers and other drugs (>90%). The removal of alkylphenols was not complete with UV and hydrogen peroxide.
(pp. 2, 13/04/2026)
IRSTEA, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UR MALY, IRSTEA
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, 13/04/2026)
iSTeP, UPMC, CNRS, LGENS, INSU - CNRS, CNRS, ENS-PSL, PSL, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
An ocean–ice coupled response during the last glacial: a view from a marine isotopic stage 3 record south of the Faeroe Shetland Gateway
The rapid climatic variability characterising the Marine Isotopic Stage (MIS) 3 (∼ 60-30 cal ka BP) provides key issues to understand the atmosphere-ocean-cryosphere dynamics. Here we investigate the response of sea-surface paleoenvironments to the MIS3 climatic variability through the study of a high resolution oceanic sedimentological archive (core MD99-2281, 60 • 21 N; 09 • 27 W; 1197 m water depth), retrieved during the MD114-IMAGES (Interna-tional Marine Global Change Study) cruise from the southern part of the Faeroe Bank. This sector was under the proximal influence of European ice sheets (Fennoscandian Ice Sheet to the East, British Irish Ice Sheet to the South) during the last glacial and thus probably responded to the MIS3 pulsed climatic changes. We conducted a multi-proxy analysis of core MD99-2281, including magnetic properties, x-ray fluorescence measurements, characterisation of the coarse (> 150 µm) lithic fraction (grain concentration) and the analysis of selected biogenic proxies (assemblages and stable isotope ratio of calcareous planktonic foraminifera, dinoflagellate cyst-e.g. dinocyst-assemblages). Results presented here are focussed on the dinocyst response, this proxy providing the reconstruction of past sea-surface hydrological conditions, qualitatively as well as quantitatively (e.g. transfer function sensu lato). Our study documents a very coherent and sensitive oceanic response to the MIS3 rapid climatic variability: strong fluctuations, matching those of stadial/interstadial climatic oscillations as depicted by Greenland ice cores, are recorded in the MD99-2281 archive. Proxies of terrige-neous and detritical material suggest increases in continental advection during Greenland Stadials (including Heinrich events), the latter corresponding also to southward migrations of polar waters. At the opposite, milder sea-surface conditions seem to develop during Greenland Interstadials. After 30 ka, reconstructed paleohydrological conditions evidence strong shifts in SST: this increasing variability seems consistent with the hypothesised coalescence of the British and Fennoscandian ice sheets at that time, which could have directly influenced sea-surface environments in the vicinity of core MD99-2281.
(Climate of the Past. vol. 8, n° 1814-9324, pp. 1997-2017, 13/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, CLIMAG, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, CLIM, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, PALEOCEAN, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, NIOZ
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
(13/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LMBA, UBS, UBO EPE, CNRS
Probabilités des évènements rares sur des séries temporelles environnementales
(13/04/2026)
LMBA, UBS, UBO EPE, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LIMATB, UBS, UBO EPE, IBNM, UBO EPE
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, 13/04/2026)
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, 13/04/2026)
UR EPBX, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, ULISBOA
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, 13/04/2026)
PUC, LEGOS, IRD, UT3, Comue de Toulouse, INSU - CNRS, CNES, CNRS, UTFSM, LEGI, UJF, Grenoble INP, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS