In-water reflectance spectra measured on-board a jet-ski across a complex nearshore zone of case-2 waters during the ECORS experiment
In situ reflectance spectra have been measured during the international field experiment ECORS-Truc Vert 2008 (SW France) in the nearshore zone over a complex bathymetry and in moderately turbid waters (SPM <10 mg/l). Measurements of the atmospheric downwelling irradiance (Ed) and in-water upwelling radiance (Lu) were realized on board a jet-ski with TRIOS RAMSES sensors together with water samples to assess the optically significant seawater constituents (SPM, CDOM, Chl-a). Marine reflectance spectra were collected under low-energy swell conditions (Hs=0.5 m) in water depths of 3-25 m and after a long period of very energetic swells (Hs > 7 m). The jet-ski provides a valuable mean to gather optical data in shallow waters and in environments hard to sample with traditional coastal ships. Main results show reflectance spectra are typical of the presence of mineral particles with light absorption at short wavelengths. The shape and magnitude of the spectra are also very representative of the type of waters and bottom depth : the maximum of reflectance is reached around 500 nm in low turbidity waters (SPM<1 mg/l) while moving to the yellow spectral band (570-580 nm) in moderately turbid shallow waters (SPM=4 mg/l) where rip currents drive sediments outside the surf zone. A very original dataset has been obtained considering the synchronization of optical data, bathymetric surveys and Formosat-2 high resolution satellite image all collected the same day (5 April 2008). In the present study, this dataset is tested to inverse optical models for bathymetry retrieval in order to compute diachronic bathymetric maps as the coastline is changing very fast and need frequent updates of the bathymetry.
(pp. 8 p, 01/10/2008)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Cartographie des faciès bio-sédimentaires du Bassin d'Arcachon à partir de l'imagerie FORMOSAT-2
(pp. 10 p, 01/10/2008)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UB, LERAR, COAST, IFREMER
The impact of lateral carbon fluxes on the European carbon balance
To date, little has been written about the important role played by processes transporting carbon laterally over continents, and from continents to oceans. These processes have an impact on the CO2 budgets and on the carbon budgets at local, regional and continental scales. We estimated the impact on the European carbon balance of the transport of carbon by the trade of wood and food products, by the emission and oxidation of reactive reduced carbon species, and by rivers and freshwater systems up to estuaries. The analysis is completed by new estimates of the carbon fluxes of coastal seas. The magnitude of the CO2 and carbon fluxes caused by lateral transport over Europe is comparable to current estimates of carbon gain by European ecosystems. At the continental level, we estimate a CO2 sink over Europe of 140 TgC yr-1 and a carbon sink of 50 TgC yr-1 being caused by lateral transport processes.
(Biogeosciences. vol. 5, n° 1726-4170, pp. 1259-1271, 05/09/2008)
LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, ICOS-ATC, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, SISYPHE, UPMC, EPHE, PSL, PSL, CNRS, SEOS, UVIC, MERMAID, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA
Interglacial variability (MIS 5 and MIS 7) and dinoflagellate cyst assemblages in the Bay of Biscay (North Atlantic)
The interglacial periods of the late Quaternary are frequently investigated as they constitute potential analogues for our modem climate and may shed light on the key questions of natural climate variability and future developments. The aim of this work is to reconstruct the paleoenvironmental history of Marine Isotope Stages (MIS) 5 and 7 in deep-sea sediments of the northern Bay of Biscay (North East Atlantic Ocean). On the basis of a multiproxy compilation, including analysis of dinoflagellate cyst assemblages, we discuss the nature of the paleoenvironmental and paleoclimate changes that took place in this region. Recurrent successions Of Species marking the beginning and the Termination of the Interglacial Complexes (MIS 5 and MIS 7) revealed a coherent scheme of water mass migration during these key transitional periods. Moreover, our data extend knowledge about the ecology of several dinoflagellate taxa. In particular, we discuss the ecology of Spiniferites septentrionalis and note that this species can be used as a biostratigraphical tracer in North Atlantic Quaternary sediments, until a major event of iceberg calving occurred during MIS 6. dated to around 150 ka BP. The dinocyst Spinferites mirabilis appears to be an important proxy for recognizing warm intervals within Interglacial Complexes. During MIS 5e, the Last Interglacial, this species is represented by the highest percentages ever recorded in sediments from the North Atlantic region. Peak occurrence of this species during MIS 7 indicates that substage MIS 7c, the second warm interval of the Penultimate Interglacial, represents the climatic optimum during the MIS 7 Interglacial Complex. (C) 2008 Elsevier B.V. All rights reserved.
(Marine Micropaleontology. vol. 68, n° 0377-8398, pp. 136-155, 01/07/2008)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Use of Biotic Indices in semi-enclosed coastal ecosystems and transitional waters habitats - Implications for the implementation of the European Water Framework Directive
This study deals with the application of macrozoobenthos-based biotic indices (BI) within the frame of the implementation of the European Water Framework Directive. More precisely, this study aimed at assessing the performance of five recently developed methodologies (BI) for the assessment of ecological quality status (EcoQ) in two semi-enclosed, sheltered coastal ecosystems and in one transitional water body situated along the Western French coast, namely Marennes-Oléron Bay, Arcachon Bay, and the Seine Estuary. This study showed that these five indices rarely agreed with each other, describing very different pictures of the overall EcoQ of the three study sites. This work also clearly underlined the limitations of these approaches, notably the dependency of most of these BI and the resulting EcoQ classifications on habitat characteristics, more particularly to natural levels of sediment silt–clay content and the location of stations in the subtidal or the intertidal. The implication of our observations concerning the use of these BI for implementation of the WFD is discussed in terms of definition of habitat-specific reference conditions and necessity to adjust thresholds to the particular habitat occurring in semi-enclosed ecosystems. Meanwhile, the unmodified use of these BI severely impaired accurate assessment of EcoQ and decision-making on the managers’ point of view.
(Ecological Indicators, n° 1470-160X, pp. 360-372, 01/07/2008)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LOG, INSU - CNRS, ULCO, CNRS, IRD [Ile-de-France], GIP-Seine-Aval, LIENSs, INSU - CNRS, ULR, CNRS, CRELA, IFREMER, ULR, CNRS, IFREMER
In vitro study of the effects of cadmium on the activation of the estrogen response element using the YES screen
(Marine Environmental Research. vol. 66, n° 0141-1136, pp. 108, 11/06/2008)
ULH, NU, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Longshore transport estimation and inter-annual variability at a high-energy dissipative beach: St. Trojan beach, SW Oléron Island, France
(Continental Shelf Research. vol. 28, n° 0278-4343, pp. 1316-1332, 01/06/2008)
LNEC, CLDG, ULR, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, IMB, UB, Bordeaux INP, CNRS
Robust Statistical Approaches for Sib-Pair Linkage Analysis of Quantitative Trait Loci
(25/05/2008)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, MSH, LMBA, UBS, UBO EPE, CNRS
Effects of dietary methylmercury on zebrafish skeletal muscle fibres
Mercury and more specifically methylmercury have been reported as hazardous environmental pollutants able to accumulate along the aquatic food chain with severe risk for animal and human health. Adult male zebrafish (Danio rerio) were distributed in two groups: a control group (fed with uncontaminated food) and a MeHg-contaminated group (fed with food containing 13.5μgHgg(-1) (dry wt)). Five fish per condition were removed after 7, 21 and 63 days. Bioaccumulation of mercury was determined and muscle samples from control and exposed groups were fixed for histological and ultrastructural studies. In contaminated muscles were observed a decrease of the inter-bundle surface, mitochondria with variable shapes, sizes and cristae disorganization, also decreasing the surface area and inter-bundle surfaces. Indeed, damage in the endoplasmic reticulum cisternae was observed. For statistical evaluation the damages in mitochondria was quantified by image. According to the current results, methylmercury affects the structure of fibre cells of D. rerio after trophic and low dose exposure.
(Environmental Toxicology and Pharmacology. vol. 25, n° 1382-6689, pp. 304-309, 01/05/2008)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Cadmium uptake by the European eel: Trophic transfer in field and experimental investigations
(Ecotoxicology and Environmental Safety. vol. 70, n° 0147-6513, pp. 10-19, 01/05/2008)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LMBA, UBS, UBO EPE, CNRS