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Le projet TREMOR est un des projets de l’appel d’offre AMI Au fil de l’eau lancé par le Cresica. Il (2018-2020) a pour objectif de mieux comprendre l’origine, les sources et les puits de la MOD identifiée dans les rivières et d’évaluer l’influence de la matière organique dissoute sur la dissémination et la toxicité des élèments traces métalliques au sein du littoral à l’aval des sites miniers.

International audience

International audience

International audience

Despite low concentrations of trace metals (TM) in natural waters, some of them are listed as priority pollutants - Hg, Cd, Pb, Ni, Cu. One of the major pollution sources to coastal waters are nautical marinas and harbours. Besides characterized by elevated levels of TMs, a high variability in TM concentrations occurs in these regions. Consequently, a classical discrete sampling is not adequate sampling methodology and passive sampling, such is diffusive gradients in thin films (DGT) is preferred. In this study we examined the applicability of DGT technique for short-term and long-term study of TM in marine/estuarine environments. A small marine harbour in Rijeka town was examined for 5-months period, with sequential DGT deployment over 2-weeks period. Two estuarine locations specified as “clean” and “polluted” ones within Šibenik bay were examined during different seasons, applying 5-days deployment period. Discrete samples were also taken: each 2 weeks at Rijeka harbour, and once or twice each day at Šibenik bay resulting in 6 composite samples. In addition, a speciation modelling was performed for comparison purposes, whereas labile Cu was also measured by anodic stripping voltammetry (ASV) for study performed in Šibenik bay. No correlation between dissolved and DGT-labile concentrations was obtained in Rijeka harbour due to rare discrete sampling, indicating high temporal variability of TM. The percentages of DGT-labile metal concentrations varied among metals with the following order: Cu90% for Cd. A linear relationship between ASV-labile and DGT-labile Cu concentrations was obtained, with slightly lower concentrations measured by ASV. Measured and predicted DGT-labile concentrations of TM agreed well if partial accumulation of organic complexes is considered by the model. DGT technique can be successfully used to determine potentially bioavailable TM concentrations in estuarine conditions and is preferable for monitoring purposes. Acknowledgement: This research was realized within MEBTRACE project (IP-2014- 09-7530), financially supported by the Croatian Science Foundation.

International audience; Today, chlordecone (CLD), anorganochlorine pesticide spread on the tocontrol populations theis health, political crisis in the French WestIndies FWI). the health measure simplemented by the authorities to CLD from reaching the consumer's plate, the population continues to be exposed. A definitive solution to the problem would be to destroy the CLD stockin the soil.

The distribution and speciation of selected trace metals (TM) (Cd/Pb/Cu/Ni/Co) were studied in the water column of the highly stratified estuary by using stripping voltammetry and diffusion gradient in thin films (DGT) techniques. A very good agreement between the vertical profiles of DGT-labile and dissolved TM concentrations were obtained. DGT-labile fraction ranged from >90% for Cd, to

International audience; On s’y baigne, on vient y déguster les poissons et les crustacés de la Méditerranée, on y pratique la randonnée, l’escalade, la plongée ou la plaisance et on aimerait parfois y posséder un cabanon pour pouvoir profiter pleinement de la douceur des nuits d’été : à n’en pas douter, les Calanques font rêver… Au-delà de la carte postale, ce site a une histoire complexe qui pèse sur son présent et son avenir. Considéré comme un « bout du monde » aux marges d’une cité portuaire de dimension mondiale avant de devenir, en 2012, la porte d’entrée d’un parc national destiné à accueillir des milliers de touristes, cet espace a longtemps été un lieu de relégation des industries les plus polluantes. C’est cette histoire méconnue, dont l’héritage est aujourd’hui si lourd à porter, que nous avons choisi d’évoquer à travers une approche résolument interdisciplinaire, associant étroitement sciences sociales et sciences de la nature, pour tendre vers une vision globale, base d’une réflexion sur la gestion des sites pollués sur le littoral méditerranéen.

International audience

One of the major pollution sources to coastal waters are harbors and marinas. Despite usually very low concentrations of metals in natural waters (trace metals - TM), some of them are listed as “priority” (Hg, Cd, Pb, Ni) or “other” pollutants (Cu, Zn). Monitoring of their (bioavailable) concentrations should be regularly performed in natural waters. Passive sampling is a promising approach of TM monitoring. The main advantage of diffusive gradient in thin films (DGT) technique is its ability for in-situ pre-concentration of TM, providing time weighted average (TWA) concentration of labile (reactive) TM, which are considered as potentially bioavailable/toxic. For this study representative sites within the Šibenik bay and the Rijeka harbour were selected. These sites were submitted to seasonal or permanent anthropogenic pressure by boat traffic (e.g. antifouling paints, sacrificial anode). In summer periods, a significant increase of TM concentrations (especially Cu) was evidenced in surface (brackish) layer in the Šibenik bay, which is attributed to an increased nautical traffic releasing metals from anti-fouling paints. As expected, highest concentrations of TM were found in nautical marinas and the Šibenik harbor. The fraction of DGT-labile TM, which reflects their chemical speciation (primarily, their binding to natural organic ligands), ranged from > 90% for Cd, to < 20% for Cu. Very good agreement between the vertical profiles of DGT-labile and dissolved TM concentrations suggests that the DGT technique can be successfully used for monitoring of potentially bioavailable TM concentrations. Due to the rare grab sampling (only once in 2 weeks) and inability to have composite sampling over the DGT-deployment period (2 weeks), no correlation between DGT-labile and dissolved concentrations of TM was obtained for study in the Rijeka harbor. This demonstrates the “problem” of grab sampling methodology and shows the dynamics of TM in the Rijeka harbor. In overall, results showed that there is no apparent continuous anthropogenic pollution of seawater in the Rijeka Harbor and that determined concentrations of TM were lower than prescribed by Regulation on water quality standards in Croatia (NN 89/2010).

Raspodjela i specijacija metala u tragovima (TM) (Zn, Cd, Pb, Cu, Ni i Co) i njihovo ponašanje i sudbina istraživani su u estuariju rijeke Krke tijekom ljetnog i zimskog perioda (2009. – 2013). Uzorkovanja su provedena u trima karakterističnim slojevima (bočatom, međusloju i morskom). Dodatno je istražen i utjecaj nautičkog prometa u Šibenskom zaljevu tijekom jednogodišnjeg perioda. Koncentracije TM niže su u rijeci Krki nego u vodi otvorenog dijela Jadrana. Nekonzervativno ponašanje u površinskom sloju estuarija, uočeno kod većine TM, primarno je uzrokovano unosom metala u području Šibenskog zaljeva. Detaljno "mapiranje“ zaljeva pokazalo je da su luka i nautička marina područja s najvišom koncentracijom TM. Znatan porast Cu i Zn u cijelom estuariju tijekom ljetnih mjeseci u izravnoj je vezi s pojačanom nautičkom aktivnošću, odnosno vezan je za otpuštanje metala iz protuobraštajnih boja na plovilima.

A review of the results of the contaminants input from the large Mediterranean city (Marseilles) into the coastal zone is presented.

Transfer of contaminants from the urbanized area and its behaviour upon arriving in coastal zone were investigated

The Krka estuary is linking the unpolluted karstic Krka river to Šibenik bay (Croatia) in the East of the Adriatic Sea. The estuary is oligotrophic with low organic matter and low naturally occurring trace metals content. It is permanently vertically stratified along its total 22 km length, with strong salinity gradient of more than 20 salinity units within 1 meter, usually located at ca. 2 m depth. Hydrological conditions (Krka river flow) are the main factors that controls the thickness and the salinity of the upper brackish layer (at a seasonal scale), while weather (wind, precipitation) has an influence on shorter time scale (days to weeks). To gain insights into the chemical distribution and behavior of trace metals in the estuary, several surveys were undertaken between 2008 and 2012 (winter and summer periods). The distribution of trace metals along estuarine transect was studied at 15 sites (3 depths per site) during 2 contrasted seasons. A high- resolution surface mapping (40 sites) of Šibenik bay was done in summer to identify the main sources of trace metals. Finally, two sites (considered as “clean” and “polluted”, respectively) were selected in Šibenik bay for detailed study of trace metals dynamic using diffusive gradient in thin film (DGT) and anodic (ASV) and cathodic (CSV) stripping voltammetry. DGT devices with open and restrictive pores were deployed at six depths for 5 days (during a total of 5 separate campaigns). Discrete samples were daily collected (once or twice a day) at each depth to make up composite samples in which dissolved and total metal concentrations (Zn, Cd, Pb, Cu, Ni, Co), were determined by voltammetry in addition of Cu complexation parameters (ligand concentration and stability constants). DGT-labile metal concentrations were measured by HR ICP-MS and compared to voltammetric results (Thermo Element 2). In summer periods, a significant increase of metal (especially Cu) concentrations was occurring in surface (brackish) layer which is attributed to an increased nautical traffic releasing metals from anti-fouling paints. In the bottom seawater layer, which has countercurrent comparing to surface layer, an upstream increase of metal content was recorded due to the progressive enrichment of that layer by metals scavenged from the more polluted upper (surface) layer. As expected, highest concentrations of metals were found in nautical marinas and Šibenik harbor. Vertical distribution of DGT labile metals displayed the same decreasing trend with depth as the one observed for total dissolved metals. The percentage of DGT-labile metal was >90% for Cd, ~60% for Ni, ~50% for Pb and >20% for Cu but varied due to the different affinity of metals to dissolved organic matter (DOM), as well as different metal/DOM ratios. Although expected to be markedly lower, DGT-labile metal concentrations measured using restrictive pore devices were only slightly lower (

Distribution of trace metal(oid)s (Zn, Cd, Pb, Cu, Ni, Co and As) along vertically stratified Krka river estuary was studied. The concentrations of trace metals are maintained at low levels across the estuary during winter, because of low input of trace metals by the Krka River and the lack of permanent diffusive sources. Localized anthropogenic influence was identified in the harbor of Šibenik town and in the two nautical marinas. However, due to the intensive nautical traffic during summer periods, a significant increase of metal concentrations (especially of Cu and Zn) in upper brackish layer was evidenced as a consequence of release of metals from the antifouling paints.

An evaluation of Diffusive Gradients in Thin films (DGT) technique for speciation of trace metal(oid)s in relation to their bioavailability was performed in the stratified Krka river estuary (Croatia). Chelex-100 based DGT probes with both open and restrictive pores were used for speciation of Zn, Cd, Pb, Cu, Ni and Co, while iron-hydroxide resin was used for As speciation. The percentage of DGT-labile concentrations varied from >90% for Cd, down to ~20% for Cu. The difference between open- and restrictive-pores was unexpectedly small. An increase of total dissolved and DGT-labile As concentrations was observed with increase of salinity.

Coastal environments are known to be strongly influenced by various continental inputs, leading to potential increase in the different environmental compartments (water column, sediment, biota, …) of inorganic (e.g. metals, metalloids, …) and organic (e.g. PAH, PCB, pharmaceuticals, …) contaminants which are naturally present at trace or ultra-trace levels. Among all these possible sources of marine pollutions, large coastal cities impact is one of the most worrying, especially in the Mediterranean Sea, due to the rapid population increase all around the coasts. These inputs, partly diffusive and strongly linked to weather conditions (e.g. episodic intensive rain events leading to important urban/industrial land weathering) have to be carefully studied to be compared to other contaminant sources as large river or atmospheric inputs. In such context, the evaluation of trace metals dynamic and fate in coastal environments is a complex issue, which needs the use/development of numerous sampling, analytical, experimental and modelling tools. The present talk will be illustrated by recent results obtained in the framework of different research programs (MARSECO, GIRAC-PACA, CARTOCHIM, PHC COGITO, …) in 3 contrasted Mediterranean coastal areas: (1) the Marseille (France) bay, a large agglomeration directly connected to the open sea, (2) the Toulon bay (France), a semi-closed area presenting an important contamination of its sediments and (3) the Krka river estuary (Šibenik bay, Croatia), a stratified and oligotrophic estuary with ultra- trace levels of metals except in summer due to significant inputs from nautical activities (e.g. antifouling paints).

Behaviour and fate of trace metals originating from urban area of large city (Marseilles, France) was investigated.

An impact of the trace metals release from the antifouling paints (from boats) were investigated in a stratified Krka river estuary.