Consistent patterns of spatial variability between NE Atlantic and Mediterranean rocky shores
(Journal of the Marine Biological Association of the United Kingdom. vol. 97, n° 0025-3154, pp. 539-547, 01/05/2017)
SBR, UPMC, CNRS, HCMR, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, IAMC, CNR, IRSNB / RBINS, LIENSs, INSU - CNRS, ULR, CNRS, IRSNB / RBINS, DIII, UNIPV, LOV, OOVM, UPMC, INSU - CNRS, CNRS, UPMC, INSU - CNRS, CNRS, GPS, UPD7, CNRS, AD2M, SBR, UPMC, CNRS, UPMC, CNRS, BioArch, MNHN, CNRS, NIOO-KNAW
Essence of the patterns of cover and richness of intertidal hard bottom communities: a pan-European study
(Journal of the Marine Biological Association of the United Kingdom. vol. 97, n° 0025-3154, pp. 525-538, 01/05/2017)
NIOO-KNAW, HCMR, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, IAMC, CNR, IRSNB / RBINS, LIENSs, INSU - CNRS, ULR, CNRS, IRSNB / RBINS, SBR, UPMC, CNRS, DIII, UNIPV, LOV, OOVM, UPMC, INSU - CNRS, CNRS, UPMC, INSU - CNRS, CNRS, GPS, UPD7, CNRS, BioArch, MNHN, CNRS
Data Treatment in Environmental Sciences
Data Treatment in Environmental Sciences presents the various methods used in the analysis of databases, obtained in the field or in a laboratory, by focusing on the most commonly used multivariate analyses in different disciplines of environmental sciences – from geochemistry to ecology. The book examines the principles, application conditions and implementation (in R software) of various analyses before interpreting them. The wide variety of analyses presented allows us to treat datasets, both large and small, which are often limited in terms of available processing techniques. The approach taken by the author details (i) the preparation of a dataset prior to analysis, in relation to the scientific strategy and objectives of the study, (ii) the preliminary treatment of datasets, (iii) the establishment of a structure of objects (stations/dates) or relevant variables (e.g. physicochemical, biological), and (iv) how to highlight the explanatory parameters of these structures (e.g. how the physico-chemistry influences the biological structure obtained).
(01/05/2017)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Contrasting sediment records of marine submersion events related to wave exposure, Southwest France
Sediment records of two contrasting backshore coastal marshes, extremely vulnerable to recent and historical marine flooding events, located on the SW coast of France, have been investigated using a multiproxy approach. The studied marshes are 30 km apart and have been flooded by similar storm events (7 marine floods in the last 250 years). One is located in a wave-exposed coast but isolated from the sea by a sediment barrier, whereas the other is located in a sheltered estuarine environment and isolated from the sea by a dike. One core was collected in each marsh and information on grain-size, foraminifera, shell contents and stable carbon isotopes was obtained along with an age model using 210Pb, 137Cs and 14C. Core data combined with historical maps give evidence of a typical estuarine backfilling, part of the Holocene regressive parasequence, including an intertidal mudflat at the base and a backshore environment at the top. Despite the absence of grain size anomalies, marine flood-related sedimentation in the backshore area of both marshes is identified by a mixture of marine and terrestrial features, including marine fauna, vegetation debris and variation in the δ13C signature of the organic fraction. Very low sedimentation rates between flood events and/or bioturbation prevents the identification of individual episodic marine floods in the sediment succession. Comparison of the two sedimentary successions shows that the foraminifera deposited by marine submersions are of two different types. Foraminifera are monospecific and originate from the upper tidal mudflat in the sheltered marsh; whereas in the backshore marsh located in a wave-exposed environment, they show higher diversity and originate from both shallow and deeper water marine environments. This study shows that wave exposure can control the faunal content of marine flood sediment records in coastal marshes.
(Sedimentary Geology. vol. 353, n° 0037-0738, pp. 158 - 170, 01/05/2017)
LIENSs, INSU - CNRS, ULR, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, BIAF, UA
Carbonate slope morphology revealing sediment transfer from bank-to-slope (Little Bahama Bank, Bahamas)
New high-quality multibeam and high-resolution seismic data reveal new observations on sediment transfer and distribution and margin morphometrics in the uppermost slope of Northeastern Little Bahama Bank between 20 and 300 m water depth. The echofacies/backscatter facies show an alongslope sediment distribution forming successive strips. The upper part of the uppermost slope corresponds to the alternation of several submerged coral terraces and escarpments that could be related to Late Quaternary sea-level variations. The terraces could either be related to periods of stagnating sea-level or slow-down in sea-level change and therefore increased erosion by waves, or periods of accelerated sealevel rise since the Last Glacial Maximum. Terraces could therefore be related to coral construction and drowing. The medium part corresponds to the marginal escarpment, a steep cemented area. The lower part of the uppermost slope shows a discontinuous Holocene sediment wedge with varying thickness between 0 and 35 m. It is separated from the upper part by a zone of well-cemented seafloor associated with the marginal escarpment. Passing cold fronts result in sediment export caused by density cascading. The associated sediment fall-out and convective sedimentation can generate density currents that form this wedge and eventually flow through linear structures on the upper slope. The survey reveals the presence of recently active channels that extend over the entire uppermost slope and interrupt the wedge. The channels connect shallow tidal channels to submarine valleys connected to the proximal part of canyons. They directly feed the canyons with platform-derived sediment forming low-density turbidity currents and could supply the deepest part of the system with coarse-grained sediment directly exported from the carbonate platform.
(Marine and Petroleum Geology. vol. 83, n° 0264-8172, pp. 26 - 34, 01/05/2017)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, VU, [Total Energies. Anciennement : Total, TotalFina, TotalFinaElf], IFPEN
From core referencing to data re-use: two French national initiatives to reinforce paleodata stewardship (National Cyber Core Repository and LTER France Retro-Observatory)
Managing paleoscience data is highly challenging to the multiplicity of actors in play, types of sampling, analysis, post-analysis treatments, statistics etc. However, a well-structured curating of data would permit innovative developments based on data and/or sample re-use, such as meta-analysis or the development of new proxies on previously studied cores. In this paper, we will present two recent initiatives that allowed us tackling this objective at a French national level: the “National Cyber Core Repository” (NCCR) and the “LTER-France retro-observatory” (ROZA).NCCR was developed under the umbrella of the French National Center fo Coring and Drilling (C2FN) thanks to the national excellence equipment project CLIMCOR. It aims at gathering on a unique website the locations and metadata of any scientific coring/drilling performed by French teams or using French facilities, whatever the type of archive it is (lake/marine sediment; ice etc.). It uses international standard, notably IGSN (for samples), ORCID (for persons) and DOI (for campaigns). NCC follows the INSPIRE ISO 19115 standard in order to catalogue the data. For continental sediment, NCCR may be fed directly on the field through a specifically developed mobile application.Based on NCCR, further initiatives may be led. In particular, under the umbrella of LTER-France (Long Term Ecological Research), we developed ROZA in order to facilitate the re-use of data and samples. Here the idea is to capitalise the knowledge on a given lake from which several sediment cores can be taken through time. In that aim we selected at least one lake from each of the 13 areas composing the network LTER-France. To enter the database, a set of mandatory data must be provided under a pre-determined format. In that case, the insertion of ROZA within the network LTER will favor to use of paleodata by non-paleodata scientists, in particular ecologists.
(01/05/2017)
EDYTEM, USMB [Université de Savoie] [Université de Chambéry], CNRS, Fédération OSUG, LTSER-ZAA, RZA, INEE-CNRS, CNRS, RZA, INEE-CNRS, CNRS, LGP, UP1, UPEC UP12, CNRS, LTSER-ZABrI, RZA, INEE-CNRS, CNRS, LTSER-ZAS, RZA, INEE-CNRS, CNRS, LTSER-ZABR, RZA, INEE-CNRS, CNRS, LTSER-ZAL, RZA, INEE-CNRS, CNRS, LETG, UNICAEN, NU, UA, EPHE, PSL, UBO EPE, UR2, CNRS, IGARUN, UN, DTI, INSU - CNRS, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Two and three-dimensional shoreline behaviour at a MESO-MACROTIDAL barred beach
(Journal of Coastal Conservation: planning and management. vol. 21, n° 1400-0350, pp. 381-392, 28/04/2017)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Estimating groundwater discharge in the coastal lagoons of La Palme and Salses-Leucate along the French Mediterranean coastline by using radium isotopes
Although submarine groundwater discharge (SGD) has been investigated in many places of the world, very few studies were conducted along the French Mediterranean coastline, despite presence of several well-known karstic springs. Almost no information is available on the fluxes of water and chemical elements associated with these systems and on their potential impact on the geochemical cycling and ecosystems of the coastal zones. In this study, we report airborne thermal infrared (TIR) images that allowed us to locate fresh groundwater inputs in the coastal lagoons of La Palme and Salses-Leucate. The four radium isotopes (223Ra, 224Ra, 226Ra, 228Ra) were analyzed in these coastal lagoons and along transects conducted on board RV NEREIS II between the coast and offshore (between 200 m and 8 km). We also analyzed major elements, nutrients (nitrates, phosphates and silicates), DIC, DOC, DON, DOP, as well as several trace elements in these water samples. A mass balance of radium isotopes was used to quantify SGD fluxes and to determine the fluxes of nutrients and other chemical species associated with SGD. Ra isotopes were also used to estimate the residence time of the waters in the lagoons.
(23/04/2017)
LEGOS, IRD, UT3, Comue de Toulouse, INSU - CNRS, CNES, CNRS, CEREGE, IRD, INRA, AMU, CdF (institution), INSU - CNRS, CNRS, LOMIC, OOB, UPMC, CNRS, UPMC, CNRS, LOMIC, INSU - CNRS, SU, CNRS, OOB, SU, CNRS, GET, IRD, UT3, Comue de Toulouse, INSU - CNRS, CNES, CNRS, HSM, IRD, INSU - CNRS, UM, CNRS, Karst, HSM, IRD, INSU - CNRS, UM, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Recent marine deposits reconstruction of two depositional environments of the French Atlantic coast
This work provides a 300-yr high-resolution record of past storm and/or tsunami events using a multi-proxy analysis (137Cs and 210Pb dating, chemical composition and grain size) of sedimentary deposits from two coastal depositional environments of the French Atlantic coast. We analyse two wetland areas situated just behind a narrow coastal sand strip: 1) the Mer Blanche and 2) the Turballe. Evidence for strong extratropical storms and /or tsunamis events can be identified in this central part of the Bay of Biscay from the XIXth to the XXth century. Nine short sediment cores were collected in August 2016 using gravity type corer of 10 inner diameter and 100 cm length. Each core was longitudinally sliced, each half section photographed and described. High-resolution elemental analyses of split sediment cores were done using an Avaatech XRF core scanner. Then sediment cores were sampled every 0.5 cm. Grain size analysis was done using a Malvern 2600 laser beam grain sizer; organic carbon was measured by Leco induction furnace. 137Cs, 210Pb and 226Ra activities were measured on about 2 g dried sediment using a low background, well-type micro- spectrometer (Canberra). The 210Pb in excess, which is used for dating, was calculated as the difference of measured 210Pb and of its supported activities (226Ra). The history information is performed using historical documents including narrative sources, ancient maps, records of cities repairs, surveys conducted after a disaster, newspaper from different departmental and national archives, and meteorological data. Coastal depositional environments were affected hardest by extreme environmental and climatological events during the last century. In the Mer Blanche core, three extreme episodes can be observed: i) at 36 cm, sediment is characterized by coarser sand and higher Sr/Al ratio, this episode coincides with a high tidal wave in spring 1937; ii) at 55 cm, we observe the presence of many gravels, they dates back to the high tidal wave of 1924 and iii) at 65 cm, the presence of another coarse pebble layer is attributed to a series of severe storms associated with coastal flooding episodes between 1910 and 1913.
(. vol. 19, pp. EGU2017-14341, 23/04/2017)
LETG - Nantes, UNICAEN, NU, EPHE, PSL, UBO EPE, UR2, CNRS, IGARUN, UN, UN, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Rôle de l'espèce ingénieure Upogebia pusilla dans le fonctionnement biogéochimique des écosystèmes intertidaux à herbier (Zostera noltei) du bassin d'Arcachon
Dans le bassin d’Arcachon, le crustacé thalassinidé Upogebia pusilla habite préférentiellement les vasières intertidales colonisées par les zostères naines (Zostera noltei) où il trouve la stabilité sédimentaire indispensable à l’établissement durable de son terrier. Du fait de la profondeur de ce dernier (> 30 cm) et de sa grande mobilité, cette espèce ingénieure a souvent été négligée dans les études antérieures ayant pour objectif de mieux comprendre le rôle des communautés macro-benthiques dans le fonctionnement des herbiers de phanérogames et les conséquences de leur régression rapide. Ce manuscrit présente une étude intégrée du rôle d’U. pusilla dans le fonctionnement de son écosystème en s’attachant particulièrement à caractériser et quantifier les relations entre (1) ses différentes activités (fouissage, ventilation, locomotion, …), (2) les modes de bioturbation qui en résultent et (3)leurs impacts respectifs sur la dynamique biogéochimique sédimentaire. Ce travail montre qu’U. pusilla engendre un remaniement et une bioirrigation intenses de la matrice sédimentaire qui l’entoure. Sa présence stimule ainsi fortement la reminéralisation de la matière organique sédimentée et les échanges de solutés à travers l’interface eau-sédiment.Bien que l’influence d’U. pusilla sur ces processus écologiques et biogéochimiques soit très dépendante des conditions environnementales (e.g., saisonnalité, prévalence parasitaire),l’ensemble de mes résultats suggère que le déclin progressif de ses populations, conséquence directe de la dégradation de son habitat, est susceptible de fortement altérer le fonctionnement global des écosystèmes du bassin d’Arcachon.
(19/04/2017)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS