Flux estimation, temporal trends and source determination of trace metal contamination in a major tributary of the Seine estuary, France
Anthropogenic impacts on rivers have increased significantly over the past ~150 years, particularly at the beginning of the industrial revolution. Among other signs, this impact is manifested through the addition of trace metals and metalloid elements to rivers. The Eure River watershed in France covers an area of 6017 km2 and is a major tributary of the Seine estuary. It is not exempt from anthropogenic pressures and has been exposed to significant metal discharges over the last 80 years. The average concentrations of metals (i.e., Cr, Co, Ni, Cu, Zn, Ag, Cd, Sb, and Pb), in suspended particulate matter currently transported by the river are high compared to the local geochemical background. Moreover, the lack of correlation between concentration variations and the hydrosedimentary behaviour of the Eure River suggests that the river is currently under anthropogenic pressure. Analysis of sediment cores indicate strong As contamination during the 1940s, Cr, Co, Ni, Cu, Zn, Ag, and Cd contamination during the 1960s and 1970s, and Sb and Pb contamination during the 1990s and 2000s. The enrichment factors calculation suggests that total anthropogenic pressure within the Eure River watershed since the 1940s was comparable or higher than those in many other French watersheds. An estimation of particulate metal flux in 2017 shows that the Eure River watershed contributed to 7, 8, 9, 10 and 16% of total inputs to the Seine estuary in Cr, Cu, Zn, Cd and Pb respectively. Moreover, the estimation of past theoretical flux indicates that during the 1990s the Eure River watershed was the main contributor of particulate Pb to the estuary. The use of Pb isotopes has revealed that this contamination was primarily of industrial origin.
(Science of the Total Environment. vol. 724, n° 0048-9697, pp. 138249, 01/07/2020)
UNICAEN, NU, COBRA, IRCOF, UNIROUEN, NU, INSA Rouen Normandie, INSA, NU, CNRS, UNIROUEN, NU, INSA Rouen Normandie, INSA, NU, INC3M, UNICAEN, NU, ENSICAEN, NU, ULH, NU, UNIROUEN, NU, INSA Rouen Normandie, INSA, NU, INC-CNRS, CNRS, INC-CNRS, CNRS, M2C, UNICAEN, NU, INSU - CNRS, UNIROUEN, NU, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LDO, INSU - CNRS, UBO EPE, CNRS, IFREMER, CEREGE, IRD, AMU, CdF (institution), INSU - CNRS, CNRS, INRAE, EDYTEM, USMB [Université de Savoie] [Université de Chambéry], CNRS, Fédération OSUG, PSL
Model-based adaptive filtering of harmonic perturbations applied to high-frequency noninvasive valvometry
In this paper, a model-based adaptive filter is used to suppress electrical noise in a high-frequency noninvasive valvometry device, which is part of an autonomous biosensor system using bivalve mollusks valve-activity measurements for ecological monitoring purposes. The proposed model-based adaptive filter uses the dynamic regressor extension and mixing method to allow a decoupled estimation of the parameters. Once the desired regression form of the output model is obtained, a fixed-time estimation approach is used to identify its parameters. By applying these two techniques, a flexible filter structure is obtained with the property of retaining the major relevant components of interest of the original valve-activity signals, even in the case when the unwanted signal frequency components are in the same frequency range as the useful variables.
(01/07/2020)
VALSE, Inria, CRIStAL, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Perturbations comportementales, physiologiques et cellulaires chez des mollusques bivalves exposés à un pétrole brut dans un contexte mono ou multistress.
L’utilisation d’outils adaptés, efficaces et fiables est fondamentale pour mesurer et contrôler l’impact environnemental autour des installations industrielles. Robuste, autonome et permettant un suivi à distance et en ligne, la Valvométrie HFNI (Haute Fréquence Non Invasive) est une solution possible pour le biomonitoring des écosystèmes aquatiques. Elle permet l’étude à distance et en temps quasi-réel du comportement et de différents traits de vie de groupes de mollusques bivalves dans le milieu naturel par numérisation de leur activité valvaire. Les animaux sont ainsi utilisés comme des témoins représentatifs de la qualité de l’eau, capables de traduire la survenue d’évènements modifiant leur environnement. Détecter rapidement le début d’une perturbation et identifier sa nature sont des éléments clés du processus de réduction du risque environnemental. A ce titre, le premier objectif de cette thèse était d’analyser la capacité de réponse comportementale face à un pétrole brut de mollusques bivalves instrumentés avec la Valvométrie HFNI en situation multistress, représentative d’un contexte environnemental réaliste. Le second objectif était d’évaluer les perturbations sous-jacentes de leur milieu intérieur lors de l’exposition au pétrole brut et mieux comprendre le mécanisme des changements de comportement. Pour ce faire, des études ont été réalisées chez deux espèces de mollusques bivalves, la palourde d’eau douce Corbicula fluminea et l’huitre marine Magallana gigas, en conditions semi-naturelles ou contrôlées de laboratoire, avec des concentrations de pétrole brut constantes ou variables, environnementales (et dans un cas létales), et en présence de différents facteurs de stress additionnels : la température de l’eau, la turbidité, la présence de baryum, de pollution sonore ou d’hypoxie. La réponse comportementale au pétrole brut s’est avérée (i) claire et discernable dans la majorité des situations créées et (ii) fonction de la concentration, ce qui permet de proposer un schéma global d’évolution d’indices valvométriques dans la gamme 0 – 60 mg·L-1. Les perturbations du milieu intérieur ont été évaluées par une approche de protéomique sur des tissus en relation avec l’activité comportementale (branchies, muscles, ganglions nerveux). Quel que soit le tissu étudié, l’espèce ou les conditions d’exposition, les résultats traduisent une modification des processus métaboliques et cellulaires avec un impact toxicologique fonction de la contamination quantifiée par des dosages de HAP dans les tissus ou des valeurs nominales d’exposition. Ces analyses permettent d’aborder les bases explicatives du comportement chez les bivalves, de corréler comportement et changements du milieu intérieur et ouvrent la voie à des perspectives d’évaluation d’impacts en ligne et à distance.
(18/06/2020)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Reconstruction of long-term water quality trends using sediment databases: insights from a multi-criteria analysis performed on the four main French River Basins (1945 - 2018)
In the current context of increasing anthropogenic pressures on river systems, sediments can provide insightful archives to reconstruct the widespread contaminations that are reported on most large rivers across the world. Identification of the spatio-temporal trends of water quality remains challenging despite the increasing concerns that they have raised in the last several decades. Indeed, multi-criteria data syntheses are scarce at the river basin scale and source-to-estuary approaches are still needed to estimate contaminant loads delivered by rivers to the seas and to monitor the effects of public policies on contamination trends. Here, we present an approach built within the framework of the INTERPOL research program, the objective of which is to assess and compare pollution trends along major rivers of France on a multi-decadal time scale. The current research focused on the example provided by the polychlorinated biphenyls (PCBs) contamination trends that were reconstructed over the last 80 years (1945–2018) along the four main fluvial valleys in France (Rhône, Seine, Loire and Garonne Rivers). PCB analyses results (∑PCBi) conducted in the framework of both research and continuous monitoring programs and measured on different solid matrices (sediment cores, bed and flood deposits, suspended particulate matters, and dredged sediments) were compiled in this study. The relationships with socio-environmental factors were also deciphered by integrating hydrological and human spatio-temporal data (river discharge, population, urban and industrial areas).The quality of the data available varied according to the studied river: the Seine and Rhône Rivers were well documented, whereas a lower proportion of validated PCBs data (> limits of quantification) was available on the Garonne and Loire Rivers. Urban and industrial areas and accidental releases provided the main contributions to the PCB contamination of rivers downstream of Paris and Rouen (Seine River), around Lyon and its industrial corridor (Rhône River), in the Saint-Etienne and Nantes conurbations (Loire River), and probably downstream of Toulouse and Bordeaux (Garonne River). Two major temporal trends were found: (1) highly concentrated ∑PCBi releases (up to 4 mg.kg-1) until 1975, followed by a sharp decrease in ∑PCBi over the period 1975‑today (due to the implementation of environmental regulations) occurred on the Seine and the Loire Rivers. (2) ∑PCBi concentrations on the Rhône and Garonne Rivers are important until the 1990s, then decrease linearly until the 2010s and are stable since then.Calculated ∑PCBi loads since 1977 showed that the Rhône River provides the largest quantity of PCBs to the Mediterranean Sea, followed by the Seine and the Loire Rivers to the Atlantic Ocean and the English Channel, respectively. In contrast, low exports from the Garonne River to the Atlantic Ocean were reported. Through the global evaluation of PCBs fluxes delivered by rivers to the seas, we demonstrate the important role played by French rivers in the PCB contamination of European seas.
(09/06/2020)
LEHNA IAPHY, LEHNA, UCBL, ENTPE, CNRS, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, GEDI, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, M2C, UNICAEN, NU, INSU - CNRS, UNIROUEN, NU, CNRS, GéHCO, UT
Microplastic toxicity for fish : beyond simple vectors for pollutants?
During the last decades, plastics have gained interest from media, public and scientists. Plastics have been categorized as emerging pollutants particularly in the marine environment due to their ubiquity and persistence, particularly microplastics (< 5 mm, MPs). Numerous studies reported the occurrence of MPs in the marine environment (surface water, sediments). However, neither there exist standardized nor harmonized methods to evaluate their potential toxicity and their role as vector of hazardous chemicals into organism. This thesis had three main objectives, (1) the investigation of sorption of chemicals models on MPs, (2) the study of the toxic potential of these sorbed chemicals on zebrafish and (3) the characterization and the study of the toxicity of environmental MPs. The first part of the thesis aimed at the investigation of the sorption processes of three model pollutants - perfluorooctanesulfonic acid (PFOS), benzo[a]pyrene (BaP) and oxybenzone (BP3) - on pristine MPs using different sizes and polymer types. The second part studied the vectorization of the three compounds sorbed on MPs toward zebrafish (Danio rerio) embryos, juveniles and adults through direct or trophic exposures, and their toxicities. The third part investigated the toxicity of environmental samples of MPs from two sandy beaches (Guadeloupe Island, France), using the same procedure as above, as well as the characterization of additives and adsorbed chemicals through a non-target approach. Study of pollutants sorption demonstrated differences in pattern (e.g. kinetics, sorption efficiency), depending on size particles and chemical used. Potential adverse effects of MPs associated with chemicals were investigated in zebrafish embryos using OECD 236 guideline and by using a chronic exposure from larvae or juveniles up to 5-months old adults through trophic exposure. Molecular and individual toxicological endpoints were monitored during exposure. Main findings were the low acute toxicity of MPs on early life stages (embryos and larvae) exposed to particles, organic extracts or leachates. Nevertheless, the ingestion of MPs by juveniles and adults led to a significant long-term toxicity for all tested MPs albeit with different intensity according to the spiked chemicals and to the environmental samples. Deleterious effects included growth alteration, reprotoxicity, behavioral disturbances as well as hyperactivity observed in offspring of exposed fish. In conclusion, the present work revealed that (1) MPs may play a role in the vectorization of pollutants and (2) may induce significant sublethal effects in juveniles of zebrafish chronically fed with pristine MPs or MPs artificially spiked with pollutants. Same conclusions were observed (3) with environmental MPs.
(08/06/2020)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Trophic transfer of micropollutants and their metabolites in an urban riverine food web
(Environmental Science and Technology, n° 0013-936X, 04/06/2020)
METIS, EPHE, PSL, INSU - CNRS, SU, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, HEPIA
Flavonoid pattern inheritance in the allopolyploid Spartina anglica – Comparison with the parental species S. maritima and S. alterniflora
The invasive species Spartina anglica arose in Europe by a cross between the Afro-European species S. maritima (native, paternal ancestor) and the introduced North American S. alterniflora (invasive, maternal ancestor). Aqueous methanolic extracts were prepared from plant tissue for chemotaxonomical comparison between the three species and determination of the phenolic pattern inheritance in S. anglica. A total of 20 phenolic compounds were detected in the aerial tissues of S. anglica and S. alterniflora, but only seven in S. maritima. They were isolated from their respective crude extracts, and their structures were determined according to spectroscopic data analysis and chemical evidence. They all belong to the flavonoid class, with 13 of them identified as C-glycoflavonoid and seven as O-glycoflavonoid. All these products were detected for the first time from S. anglica, fourteen of them for the first time from S. alterniflora, and three of them for the first time from S. maritima. The individual concentrations in the three species were determined by quantitative HPLC. The two parental species were found to differ markedly in their foliar phenolic fingerprint, whereas that of S. anglica showed a clear maternal dominance. Eight of the fourteen major compounds identified were of maternal origin among which, six were over-expressed, only three were from paternal origin but under-regulated, while two originated from the two parents. As far as we know, this work represents the first exhaustive report of the phenolic fingerprints of S. alterniflora and S. anglica and of the phenolic pattern inheritance in S. anglica. The similarity in the phenolic chemistry of the introduced and invasive S. alterniflora to its progeny could play a role in the physiological vigour and invasion success of S. anglica. This work provide a foundation for further studies, considering the reported biological activities of C-glycosidic flavonoids and tricin derivatives, and the lack of knowledge of the ecological chemistry of the genus Spartina.
(Phytochemistry. vol. 174, n° 0031-9422, pp. 112312, 01/06/2020)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Environmental evolution of the Acholla coast (Gulf of Gabes, Tunisia) during the past 2000 years as inferred from palaeontological and sedimentological proxies
A multi-proxy approach to infer the environmental evolution and coastal dynamics was conducted on four sediment cores with the aim to decipher forcing factors shaping the coastline of Acholla (Tunisia) over the last 2000 years. The data recorded from palaeontological and sedimentological studies combined with 14C dating suggest a progression of four successive phases: (1) the first Holocene marine transgression (183 A.D.), overlying Upper Pleistocene marine sandstones, resulted in a brackish shallow-water coastal environment characterized by a mixture of lagoonal/estuarine, marine/brackish and marine/lagoonal ostracod assemblages with high species richness, (2) a high-energy event marked by the deposition of coarse bioclastic sands, rich in molluscs, charcoal particles and Tyrrhenian lithoclasts (towards 417 A.D.), (3) progradation of the coast (between 417 and 1577 A.D.), where longshore current drifts and a period of flooding/detrital input resulted in the build-up of a sandspit and the deposition of coastal sand bars, as indicated by increasing abundances of predominantly lagoonal/estuarine ostracods and molluscs. The natural sedimentation pattern was impacted by the construction of a Roman pier that accelerated the formation of the sandspit from 1577 A.D. onward (4), ultimately resulting in the complete closure of the lagoon as recorded by the expansion of saltmarshes containing a monospecific ostracod fauna (Cyprideis torosa).
(Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen. vol. 296, n° 0077-7749, pp. 217-235, 01/06/2020)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Contamination polymétallique des Lacs AQuitains et impacts Humains (CLAQH)
En 2013, une étude de l'ANSES sur la contamination par le mercure (Hg) de la chair des poissons des quatre plus grands lacs aquitains -Hourtin-Carcans (HC), Lacanau (L), Cazaux-Sanguinet (CS) et Parentis-Biscarrosse (PB)- a montré que des concentrations dépassant les recommandations de consommation (0,5 mg Hg.kg-1 poids frais) des poissons carnivores des lacs HC et L ont été observées chez le sandre (Sander Lucioperca). Cette contamination pouvant constituer un risque pour la santé humaine, un arrêté préfectoral a interdit la consommation de sandres péchés dans ces lacs. Par ailleurs, cette première étude a mis en évidence un gradient de contamination nord-sud, les poissons pêchés dans les lacs médocains (HC et L) étant plus contaminés que ceux pêchés dans les lacs landais (CS et PB). Les résultats du projet CLAQH ont confirmé ce gradient décroissant nord-sud dans la chair des poissons carnivores. Les concentrations en mercure atmosphérique mesurées ponctuellement ou accumulées dans les mousses végétales autour des lacs sont caractéristiques d’environnements dits « éloignés et vierges » de toutes sources significatives de contamination. D'autres facteurs pouvant expliquer ce gradient de contamination chez les poissons ont été étudiés, tels que la structure de la chaîne alimentaire et le rôle potentiel des plantes aquatiques dans la méthylation du Hg, la forme méthylée du mercure étant la forme la plus disponible pour les organismes biologiques et la plus toxique. Aucun des facteurs étudiés ne peut expliquer ces différences nord-sud. En revanche, un important gradient décroissant de concentrations en sulfate nord-sud a été mesuré dans les eaux et les sédiments des 4 lacs. L’enrichissement en sulfate des lacs médocains provient des zones agricoles du bassin versant du lac de Hourtin-Carcans. La présence de ces sulfates favorise le développement de bactéries sulfato-réductrices, localisées principalement au niveau du biofilm des plantes aquatiques et du sédiment, responsables de la production de méthylmercure. Cette production accrue de méthylmercure dans les lacs de Hourtin-Carcans et de Lacanau est responsable de la forte accumulation de ce métal dans les poissons carnivores de ces lacs. Cette étude préconise de ne pas consommer les poissons carnivores issus de ces deux lacs pour les personnes les plus vulnérables (femmes enceintes et enfants). Par ailleurs, douze autres éléments traces métalliques ont été analysés dans les muscles des poissons et aucun risque pour la santé et l'environnement n'a été décelé pour les métaux réglementés (Cd, Pb) et non réglementés (Cu, Zn, As, Ni, Co, V, Cr, Se, Ag, Al) par la Commission européenne.
(01/06/2020)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, ENSC, Bordeaux INP, IMS, UB, CNRS, IMS, UB, CNRS, UR EABX, INRAE, IPREM, UPPA, INC-CNRS, CNRS
Advances in reconstructing the AMOC using sea surface observations of salinity
The Atlantic meridional overturning circulation (AMOC) is one of the main drivers of climate variability at decadal and longer time scales. As there are no direct multi-decadal observations of this key circulation, the reconstruction of past AMOC variations is essential. This work presents a step forward in reconstructing the AMOC using climate models and time-varying surface nudging of salinity and temperature data, for which independent multi-decadal observed series are available. A number of nudging protocols are explored in a perfect model framework to best reproduce the AMOC variability accommodating to the characteristics of SST and SSS available products. As reference SST products with sufficient space and time coverage are available, we here choose to focus on the limitations associated to SSS products with the goal of providing protocols using independent salinity products. We consider a global gridded dataset and, additionally, a coarser SSS dataset restricted to the Atlantic and with a quite low spatial resolution (order of 10 degrees vs. 2 for the model grid). We show how, using the latter, we can improve the efficiency of the nudging on the AMOC reconstruction by adding a high-resolution annual cycle to the coarse resolution SSS product as well as a spatial downscaling to account for SSS gradient. The final protocol retained for the coarse SSS data is able to reconstruct a 100-year long AMOC period (average of 10.18 Sv and a standard deviation of 1.39 Sv), with a correlation of 0.76 to the target and a RMSE of 0.99 Sv. These values can be respectively compared to 0.85 and 0.75 Sv when using the global salinity surface observations. This work provides a first step towards understanding the limitations and prospects of historical AMOC reconstructions using different sea surface salinity datasets for the surface nudging.
(Climate Dynamics. vol. 1, n° 0930-7575, 01/06/2020)
LOCEAN-VARCLIM, LOCEAN, MNHN, IRD, INSU - CNRS, SU, CNRS, IPSL (FR_636), ENS-PSL, UVSQ, CEA, INSU - CNRS, X, CNES, SU, CNRS, UPCité, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LOCEAN-PROTEO, LOCEAN, MNHN, IRD, INSU - CNRS, SU, CNRS, IPSL (FR_636), ENS-PSL, UVSQ, CEA, INSU - CNRS, X, CNES, SU, CNRS, UPCité