Dietary bioaccumulation of persistent organic pollutants in the common sole Solea solea in the context of global change. Part 2: Sensitivity of juvenile growth and contamination to toxicokinetic parameters uncertainty and environmental conditions variability in estuaries
The amount of potentially toxic chemicals in a fish depends on various environmental factors, such as temperature and feeding ecology, which can be affected by Global Changes (GC). The main objective of the present work was to study the relative influence of temperature, food quality and food availability on the growth and contamination of juveniles of common sole (Solea solea), a marine flatfish species known to be a relevant indicator of the nursery quality. It focuses on two Persistent Organic Pollutants (CB153 and L-PFOS) of legacy and emerging concern, respectively. To achieve this, we used a toxicokinetic (TK) model in which toxicant flows are mechanistically predicted using a bioenergetic model based on the Dynamic Energy Budget (DEB) theory. This modelling framework was applied to juvenile sole from the Gironde estuary (SW France) and allows accounting for the influence of environmental conditions on fish biological processes involved in toxicant fluxes. To compare their respective influence on model predictions of age, length, and contamination at puberty, we included in a global sensitivity analysis: (1) environmental variability gathered from literature for this particular estuary and (2) TK parameters (i.e. assimilation efficiency AE and elimination rate ) variability and uncertainty gathered from literature about each contaminant but for different fish species and experimental conditions. Then, model predictions were confronted to fish contamination measurements from the Gironde Estuary with different combinations of TK parameter values from literature. Results highlighted a key role of diet composition on fish contamination and growth while water temperature only affected growth. It stressed the need to focus on GC impact on benthic communities and their consequences on juvenile fish diet for future work on GC scenarios. Furthermore, for both chemical, the range of variability of TK parameters from experiments led to underestimated fish contaminations. The best model fits were obtained using TK parameter values from model applications: from Mounier et al. (n.d.) for CB153 (Solea solea, experiment, AE=0.8 and =0 d−1) and from de Vos et al. (2008) for PFOS (food chain of the Western Scheldt estuary, The Netherlands, AE=0.8 and =0.8 10−2.d−1).
(Ecological Modelling. vol. 431, n° 0304-3800, pp. 109196, 01/09/2020)
UR EABX, INRAE, BE, IFREMER, IFREMER, LEMAR, IRD, IFREMER, UBO EPE, CNRS, IRD, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Exploring Offshore Sediment Evidence of the 1755 CE Tsunami (Faro, Portugal): Implications for the Study of Outer Shelf Tsunami Deposits
Outer shelf sedimentary records are promising for determining the recurrence intervals of tsunamis. However, compared to onshore deposits, offshore deposits are more difficult to access, and so far, studies of outer shelf tsunami deposits are scarce. Here, an example of studying these deposits is presented to infer implications for tsunami-related signatures in similar environments and potentially contribute to pre-historic tsunami event detections. A multidisciplinary approach was performed to detect the sedimentary imprints left by the 1755 CE tsunami in two cores, located in the southern Portuguese continental shelf at water depths of 58 and 91 m. Age models based on 14C and 210Pbxs allowed a probable correspondence with the 1755 CE tsunami event. A multi-proxy approach, including sand composition, grain-size, inorganic geochemistry, magnetic susceptibility, and microtextural features on quartz grain surfaces, yielded evidence for a tsunami depositional signature, although only a subtle terrestrial signal is present. A low contribution of terrestrial material to outer shelf tsunami deposits calls for methodologies that reveal sedimentary structures linked to tsunami event hydrodynamics. Finally, a change in general sedimentation after the tsunami event might have influenced the signature of the 1755 CE tsunami in the outer shelf environment.
(Minerals. vol. 10, n° 2075-163X, pp. 731, 01/09/2020)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Antarctic sea-ice and palaeoproductivity variation over the last 156,000 years in the Indian sector of Southern Ocean
(Marine Micropaleontology. vol. 160, n° 0377-8398, pp. 101894, 01/09/2020)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Impacts of land reclamation on sediment transport and sedimentary environment in a macro-tidal estuary
During the past decades, extensive coastal areas have been reclaimed along the coastline of China, while the physical mechanisms of human pressures on estuarine-sedimentation are largely unknown. This study investigates the impacts of a land reclamation activity on estuarine sedimentation in the Yalu River Estuary (YE), China. For this purpose, we perform a multidisciplinary approach that combines rare earth element (REE) sediment records and numerical simulations. REE pattern of two sediment core samples from the main estuarine branch changed from diverse to homogenous after the early 1970s, which indicates that the estuarine sedimentary environment experienced dramatic change after the land reclamation activity completed in 1975. In order to explore physical drivers behind this change, hydro-sedimentary dynamics were simulated using Finite Volume Coastal Ocean Model (FVCOM) and an improved Track Marine Plastic Debris (TrackMPD) models. After the land reclamation, model results show that: (1) the degree of flood dominance decreased, and the tidal-choking effect was enhanced in the main branch. (2) The estuary became more well-mixed due to the stronger tidal current; (3) Suspended-sediment concentration (SSC), especially SSC in the bottom layer was increased. (4) The landward sediment flux caused by tidal pumping decreased significantly and the YE may turn into a sediment source instead of a sink if more land is reclaimed in the future. Furthermore, sediments in the main branch were likely from different sources before reclamation but became a homogenous mixture afterwards. This study qualitatively demonstrates the human-induced impacts on estuarine sedimentation using a multidisciplinary method.
(Estuarine, Coastal and Shelf Science. vol. 242, n° 0272-7714, pp. 106861, 01/09/2020)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Satellite and in situ monitoring of Chl-a, Turbidity, and Total Suspended Matter in coastal waters: experience of the year 2017 along the French Coasts
The consistency of satellite and in situ time series of Chlorophyll-a (Chl-a), Turbidity and Total Suspended Matters (TSM) was investigated at 17 coastal stations throughout the year 2017. These stations covered different water types, from relatively clear waters in the Mediterranean Sea to moderately turbid regions in the Bay of Biscay and the southern bight of the North-Sea. Satellite retrievals were derived from MODIS/AQUA, VIIRS/NPP and OLCI-A/Sentinel-3 spectral reflectance. In situ data were obtained from the coastal phytoplankton networks SOMLIT (CNRS), REPHY (Ifremer) and associated networks. Satellite and in situ retrievals of the year 2017 were compared to the historical seasonal cycles and percentiles, 10 and 90, observed in situ. Regarding the sampling frequency in the Mediterranean Sea, a weekly in situ sampling allowed all major peaks in Chl-a caught from space to be recorded at sea, and, conversely, all in situ peaks were observed from space in a frequently cloud-free atmosphere. In waters of the Eastern English Channel, lower levels of Chl-a were observed, both in situ and from space, compared to the historical averages. However, despite a good overall agreement for low to moderate biomass, the satellite method, based on blue and green wavelengths, tends to provide elevated and variable Chl-a in a high biomass environment. Satellite-derived TSM and Turbidity were quite consistent with in situ measurements. Moreover, satellite retrievals of the water clarity parameters often showed a lower range of variability than their in situ counterparts did, being less scattered above and under the seasonal curves of percentiles 10 and 90.
(Journal of Marine Science and Engineering. vol. 8, n° 2077-1312, pp. 665, 28/08/2020)
IFREMER, LERBL, COAST, IFREMER, LIENSs, INSU - CNRS, ULR, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LOG, INSU - CNRS, ULCO, CNRS, IRD [Ile-de-France], SBR, SU, CNRS, FR2424, SBR, SU, CNRS, LOMIC, INSU - CNRS, SU, CNRS, OOB, SU, CNRS, LERPAC, COAST, IFREMER, IHPE, UPVD, IFREMER, CNRS, UM, MIO, IRD, AMU, INSU - CNRS, UTLN, CNRS
Flash Rips in Voodoo Land
(Journal of Coastal Research. vol. 101, n° 0749-0208, 26/08/2020)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Linking carbonate sediment transfer to seafloor morphology: Insights from Exuma Valley, the Bahamas
The depositional record of carbonate slopes provides a valuable archive of past environmental and climatic changes. Modern carbonate slopes reveal morphological variabilities (for example, gullies and canyons) shaped by episodic slope collapses and turbidity currents. Furthermore, climate-induced fluctuations in sea level regulate sediment availability and delivery to the deep-sea. Morphological and climatic controls on calciclastic sediment transfer are often complex to decipher. The aim of this study is to link seafloor morphology and depositional processes in an active carbonate submarine channel (Exuma Valley, the Bahamas) over the last 40 kyr. The dataset includes multibeam and seismic surveys, and two sediment cores retrieved from the valley axis. A series of abrupt slope-breaks, called knickpoints, occurs along Exuma Valley, and plays a key role in sediment transport and accumulation. Initiation processes proposed for knickpoint formation include bank-collapse, side gully erosion and loss of confinement. Slope collapses detected on the bathymetry prevail in the upstream muddy section of the submarine valley, as attested to by a planktic-rich debrite–turbidite couplet in the first core. In contrast, the second core collected downstream of the knickpoints train, includes 32 bioclastic sandy event-beds (i.e. turbidites). Hydrodynamic sorting generates grain segregation (for example, Halimeda-rich base versus planktic-rich top) and geochemical contrasts (Sr/Ca) in turbidites. Turbidite frequency and grain composition within beds reflect the variation of carbonate sources during glacial–interglacial periods. This research allows to link slope morphology with deposits of a modern large-scale carbonate factory, and to deduce sea-level changes over that last 40 kyr in the Bahamas. These results can provide new perspectives on the understanding of ‘source to sink’ mechanisms in carbonate systems.
(Sedimentology. vol. 68, n° 0037-0746, pp. 609-638, 26/08/2020)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Assessment of the Environmental Significance of Heavy Metals Pollution in Surficial Sediments of South Brittany Waters, France: An Ecological Risk Assessment Approach
Distribution patterns of selected heavy metals content in sediments from the Bay of Quiberon and Gulf of Morbihan were studied to understand the current heavy metals contamination due to urbanization and mariculture activities in the coastal area. Therefore, a survey was conducted and 196 sediments collected were characterized for heavy metals content using Inductively Coupled Plasma -Mass Spectrometry (ICP-MS) after mix acid digestion process.
The distribution maps of the concentrations of the heavy metals studied were produced as an isopleth map based on data interpolation by the ArcGIS software application. The association with the adverse effects on aquatic organisms was determined by the classification of the sediment according to the sediment quality guidelines. Therefore, two approaches were employed namely; direct comparison with Sediment Quality Guidelines (SQGs) by USEPA and comparison with other numerical SQGs, threshold effect level/probable effect level, and effect range low /effect range medium. In order to estimate the effect of multiple contaminations of heavy metals, the mean-ERM-quotient was calculated at each sampling point.
(06/08/2020)
NTOU, LGO, UBS, IFREMER, UBO EPE, CNRS, LBCM, UBS, UBO EPE, IUEM, IRD, INSU - CNRS, UBO EPE, CNRS, CNRS, GEO-OCEAN, UBS, IFREMER, INSU - CNRS, UBO EPE, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Corbicula fluminea: A sentinel species for urban Rare Earth Element origin
The increase in the global population, coupled with growing consumption of Rare Earth Elements (REEs), has led to increasing transfer of these emerging contaminants into the environment, particularly through the effluents from wastewater treatment plants (WWTP). The objectives of this study were to determine the geochemical quality of a French river subject to strong urban pressure (the Jalle River in the Bordeaux area) and to examine the bioavailability of natural and anthropogenic REEs in a model species of freshwater bivalve, the Asian clam Corbicula fluminea. To this end, two fractions (dissolved and total) of the water from the Jalle River were sampled and the bivalves were exposed by in situ caging during a three-month monitoring period. The REE patterns obtained showed the presence of Gadolinium (Gd) anomalies in the dissolved and total fractions as well as in Corbicula fluminea. The apparent bioavailability of natural REEs was in the following order for the dissolved fraction: Medium REEs (MREEs) > Light REEs (LREEs) > Heavy REEs (HREEs) and for the particulate fraction: MREEs > LREEs = HREEs. These results highlight the importance of the particulate fraction in the study of the bioavailability of REEs in bivalves. An increase of anthropogenic Gd (Gdanth) was observed in the dissolved fraction between the upstream site (3.4 ng.L−1) and the WWTP Downstream site (48.4 ng.L−1). The Gd anomaly observed in the water was also observed in Corbicula fluminea with a significant increase in the bioaccumulation of Gdanth, from 1.5 ± 1 ng.gDW−1 upstream to 4.1 ± 0.7 ng.gDW−1 downstream of the WWTP effluents, thus confirming the enhanced bioavailability of medical-origin Gd to freshwater bivalves. This study strongly suggests that Corbicula fluminea can be used as a sentinel species in the monitoring of Gd contamination of medical origin. It would thus appear important to consider the potential entry of this contaminant into the human food chain via other, commercially exploited bivalve species.
(Science of the Total Environment. vol. 732, n° 0048-9697, pp. 138552, 01/08/2020)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
An overview and brief description of common marine organic-walled dinoflagellate cyst taxa occurring in surface sediments of the Northern Hemisphere
Organic-walled resting cysts of planktonic dinoflagellates occur commonly in modern marine sediment where they represent, with rare exceptions, the only geologically preservable part of the life cycle. Although many species do not produce fossilizable resting cysts, upper Quaternary sediments contain a diverse cyst record that is used frequently for paleoenvironmental reconstruction and stratigraphic analysis. Reconstructions of past sea-surface conditions rely on an understanding of the distributions of dinoflagellate cysts in modern sediments linked to their respective environmental parameters, underpinned by sound taxonomy and standardized nomenclature. Stratigraphic studies additionally require knowledge of morphological details to distinguish extant from similar extinct taxa. Here, 51 dinoflagellate cyst species and two informal cyst morphotypes that are commonly encountered during routine palynological analysis of upper Quaternary marine sediments from the Northern Hemisphere are briefly described taxonomically and illustrated. In addition, their lowest stratigraphic occurrences are provided.
(Marine Micropaleontology. vol. 159, n° 0377-8398, pp. 101814 (46p.), 01/08/2020)
UNB, SEOS, UVIC, LERBO, COAST, IFREMER, AWI, GEOTOP, EPM, UdeM, UQAT, UQAR, UQAM, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LGO, UBS, IFREMER, UBO EPE, CNRS, UQAM, ISMER, UQAR