Apports rhodaniens et suivi atmosphérique des contaminants organiques persistants (PCB, PBDE, HAP, PCDD/F) dans le Golfe du Lion (2009-2010)
Dans le présent rapport sont exposés les résultats du projet ARC-MED réalisé avec un appui financier de l’Agence de l’Eau Rhône Méditerranée Corse. L’objectif principal de cette étude a été d’estimer quantitativement les charges rhodaniennes en contaminants organiques persistants entrant dans le Golfe du Lion: polychlorobiphényles (PCB), hydrocarbures aromatiques polycycliques (HAP), polybromodiphényléthers (PBDE), polychlorodibenzodioxines et furanes (PCDD/F) ainsi qu’un dérivé des pesticides organochlorés (p,p’-DDE),. Par ailleurs, la variabilité annuelle-saisonnière des teneurs en contaminants dans les diverses masses d’air a été étudiée pendant une année sur deux stations à la Seyne-sur-Mer et au Cap Ferrat. Ce suivi a permis également de caractériser la répartition des contaminants (formes particulaires et gazeuses) dans les masses d’air étudiées. Enfin, deux campagnes en mer ont été effectuées dans le Golfe du Lion. Ces campagnes ont fourni des références marines des teneurs en contaminants dissous et particulaires dans le pro-delta du Rhône et dans le Golfe du Lion.
(28/10/2026)
BE, IFREMER, IFREMER, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LOV, OOVM, UPMC, INSU - CNRS, CNRS, UPMC, INSU - CNRS, CNRS
Impact écotoxicologiques et économiques des phénomènes de sous-oxygénation et de pollution des estuaires sur l'anguille européenne (Anguilla anguilla)?
(pp. 28, 28/10/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, IFREMER, UR EPBX, IRSTEA, GREThA, UB, CNRS
Towards the evaluation of ecological consequences of hydromorphological evolutions of the Gironde estuary: A preliminary approach combining GIS and hydrodynamics modelling
Estuaries are composed of a mosaic of habitat providing various ecological functions for many biological communities and many goods and services to society. At the interface between continents and oceans, estuaries in general, and particularly large estuaries, are also environments which concentrate important ecological issues but also many environmental climatic and anthropogenic pressures. The Gironde estuary, one of the largest European estuaries, is thus an emblematic case. Historically, it has undergone major evolutions of its hydromorphosedimentary characteristics due to impacts of climate change and human activities. The aim of this work is to assess the ecological consequences of these changes through the study of the evolution of surfaces of estuarine available habitats and the knowledge of ecological functions associated with these habitats. To do this, we propose to combine two approaches: ecological and hydromorphosedimentary. First, work was undertaken to determine, from scientific literature, tolerances and preferences of representative species of the ecosystem for each of the parameters determining estuarine aquatic habitats (depth, salinity, sedimentary facies ...). Thus, combining available map data and results from a hydrodynamic model implemented in the Gironde, we can map the spatial distribution of these species in the estuary using a geographic information system (GIS). Then, we characterized the ecological functions associated with each habitat (eg. nursery role for sole, migration for eels ...). On the other hand, old maps of the environment have been digitized and analysis was undertaken to characterize the evolution of morphology, hydrological and sedimentary dynamics of the estuary in recent decades. The potential distribution maps we obtained allowed defining a kind of ecological potential that can be used as a reference for assessing effects of development issues, management measures or climate change scenarios. Results highlighted small changes in functional habitats distributions but high vulnerability of some of them (nursery grounds).
(pp. 14, 28/10/2026)
UR EPBX, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
A two-step process for the reflooding of the Mediterranean after the Messinian Salinity Crisis
The Messinian Salinity Crisis is well known to have resulted from a significant drop of the Mediterranean sea level. Considering both onshore and offshore observations, the subsequent reflooding is generally thought to have been very sudden. We present here offshore seismic evidence from the Gulf of Lions and re-visited onshore data from Italy and Turkey that lead to a new concept of a two-step reflooding of the Mediterranean Basin after the Messinian Salinity Crisis. The refilling was first moderate and relatively slow accompanied by transgressive ravinement, and later on very rapid, preserving the subaerial Messinian Erosional Surface. The amplitude of these two successive rises of sea level has been estimated at ≤500 m for the first rise and 600-900 m for the second rise. Evaporites from the central Mediterranean basins appear to have been deposited principally at the beginning of the first step of reflooding. After the second step, which preceeded the Zanclean Global Stratotype Section and Point, successive connections with the Paratethyan Dacic Basin, then the Adriatic foredeep, and finally the Euxinian Basin occurred, as a consequence of the continued global rise in sea level. A complex morphology with sills and sub-basins led to diachronous events such as the so-called 'Lago Mare'.This study helps to distinguish events that were synchronous over the entire Mediterranean realm, such as the two-step reflooding, from those that were more local and diachronous. In addition, the shoreline that marks the transition between these two steps of reflooding in the Provence Basin provides a remarkable palaeogeographical marker for subsidence studies.
(Basin Research. vol. 24, n° 0950-091X, pp. 125-153, 28/10/2026)
iSTeP, UPMC, CNRS, IPGP, INSU - CNRS, UPD7, UR, IPG Paris, CNRS, LDO, INSU - CNRS, UBO EPE, CNRS, CEREGE, IRD, INRA, AMU, CdF (institution), INSU - CNRS, CNRS, GM, IFREMER, IDES, UP11, INSU - CNRS, CNRS, GeoEcoMar, ICM, CSIC, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, ISTO, INSU - CNRS, UO, UT, NEOLAiA, CNRS, UERJ, LGENS, INSU - CNRS, CNRS, ENS-PSL, PSL, UKIM, BAS, GEOLOGY AND MINING DEPARTMENT, ITÜ, VU, ITÜ, GR, UR, INSU - CNRS, CNRS
Morphological anomalies in estuarine shrimp larvae
For several years, major exoskeletal anomalies in two species of European estuarine shrimp of the genus Palaemon have been observed. The phenomenon has been described for P. longirostris and P. macrodactylus in the Gironde estuary (France) and affects all stages of the species’ life cycles: from juvenile to adult and in both wild and laboratory-reared individuals. In the present follow-up study, the effects of these anomalies in larval stages of the two species were investigated. Regular sampling across most of the saline estuary confirmed that the post-larval stages of both species were affected. The morphological anomalies (MA) observed in the larvae were of the same type as those described for the adult stages, although more limited and primarily affecting the rostrum and cephalothorax. Larvae were reared from hatching to the post-larval stage, and the appearance of the aforementioned anomalies was observed as early as in Zoea I. This was the case even in larvae whose mothers did not exhibit anomalies. For both species, the most advanced stage was the one most affected. Also, in the rearing experiment, a greater proportion of the P. macrodactylus larvae was affected than those of P. longirostris. No significant effects ofMA on size or growth rate were demonstrated for larvae of either species in this study. Nevertheless, it provides data on larval growth that were not previously available. Further rearing experiments should be considered in order to explore any demonstrable effects of these morphological anomalies.
(Crustaceana. vol. 85, n° 0011-216X, pp. 11-25, 28/10/2026)
UR EPBX, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Factors influencing the stable carbon isotopic composition of suspended and sinking organic matter in the coastal Antarctic sea ice environment
A high resolution time-series analysis of stable carbon isotopic signatures in particulate organic carbon (δ 13 C POC) and associated biogeochemical parameters in sea ice and surface waters provides an insight into the factors affecting δ 13 C POC in the coastal western Antarctic Peninsula sea ice environment. The study covers two austral summer seasons in Ryder Bay, northern Marguerite Bay between 2004 and 2006. A shift in diatom species composition during the 2005/06 summer bloom to near-complete biomass dominance of Proboscia inermis is strongly correlated with a large ∼10 ‰ negative isotopic shift in δ 13 C POC that cannot be explained by a concurrent change in concentration or isotopic signature of CO 2. We hypothesise that the δ 13 C POC shift may be driven by the contrasting biochemical mechanisms and utilisation of carbon-concentrating mechanisms (CCMs) in different diatom species. Specifically, very low δ 13 C POC in P. inermis may be caused by the lack of a CCM, whilst some diatom species abundant at times of higher δ 13 C POC may employ CCMs. These short-lived yet pronounced negative δ 13 C POC excursions drive a 4 ‰ decrease in the seasonal average δ 13 C POC signal, which is transferred to sediment traps and core-top sediments and consequently has the potential for preservation in the sedimentary record. This 4 ‰ difference between seasons of contrasting sea ice conditions and upper water column stratification matches the full amplitude of glacial-interglacial Southern Ocean δ 13 C POC variability and, as such, we invoke phytoplankton species changes as a potentially important factor influencing sedi-mentary δ 13 C POC. We also find significantly higher δ 13 C POC in sea ice than surface waters, consistent with autotrophic carbon fixation in a semi-closed environment and possible contributions from post-production degradation, biological utilisation of HCO − 3 and production of exopolymeric substances. This study demonstrates the importance of surface water diatom speciation effects and isotopically heavy sea ice-derived material for δ 13 C POC in Antarctic coastal environments and underlying sediments, with consequences for the utility of diatom-based δ 13 C POC in the sedimentary record.
(Biogeosciences. vol. 9, n° 1726-4170, pp. 1137-1157, 28/10/2026)
UEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, BAS, NERC
Comment on "Productivity Is a Poor Predictor of Plant Species Richness
Adler et al. (Reports, 23 September 2011, p. 1750) reported "weak and variable" relationships between productivity and species richness and dispute the "humped-back" model (HBM) of plant diversity. We show that their analysis lacks sufficient high-productivity sites, ignores litter, and excludes anthropogenic sites. If corrected, the data set of Adler et al. would apparently yield strong HBM support.
(Science. vol. 335, n° 0036-8075, pp. 1441-b, 28/10/2026)
University of Milan, UNIMI, CEBC, INRA, CNRS, Uninsubria, University of Pennsylvania, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
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
A new insight for micropollutants in activated sludge: variability of influent concentrations and effects of operating parameters on removal performances
We investigated how variable were concentrations in raw wastewater for 6 beta-blockers and 10 metals. Measured concentrations suggested a different consumption of 4 beta-blockers according to the season. We observed the same variability for metals. During a day, influent concentrations were not constant. However, daily concentrations seemed to be similar for consecutive days. So a robust understanding of a treatment process implied the knowledge of influent concentrations. We studied also the influence of operating conditions on micropollutant removal. We observed that a higher temperature, a lower MLSS concentration and a higher ammonium oxidation promoted micropollutant removal.
(pp. 5, 28/10/2026)
UR MALY, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UMR Qualisud, Cirad, UM1, UM2, Montpellier SupAgro, AU, UR, UM, Montpellier SupAgro
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