Le développement des Energies Marines Renouvelables (EMR) fait partie des priorités mondiales ; il rentre également dans celles de l'Europe et de l'Etat Français.Le Conseil Départementale de la Charente Maritime (CD17), dans cette optique, et vu la situation privilégiée de son littoral, a décidé la mise en oeuvre d'une étude sur la faisabilité d'installation de sites d'essais dédiés aux systèmes hydroliens.La bathymétrie et l'hydrodynamique analysées ont conduit à cibler les systèmes de petites à moyennes puissances.Dans un second temps, un panel de variables complémentaires (usages, règlementation, environnement, etc.) sont croisées afin de nuancer localement les sites réputés favorables par la sélection préalable à l'aide des variables d'altimétrie et de courant.Cette approche multicritère s'appuie sur la compilation de couches SIG pondérées suivant l'intérêt spécifique de la problématique.Les données sont de natures et sources diverses : données maillées continues ou sectorisations vectorielles, provenant de l'IGN, de l'Ifremer, de l'Etat, de l'ULR, du CD17, etc. Les principaux attendus sont : 1) une analyse spatiale complète de la Mer des Pertuis, précisant les zones ayant une dynamique intéressante pour les développeurs, 2) une caractérisation hiérarchisée des sites, base d'élaboration de la rédaction d'un catalogue qualitatif des sites et 3) l'anticipation d'éventuels conflits d'usages entre les acteurs de la zone et le projet.La première phase de développement des outils d'analyse spatiale et de sélection des sites est présentée ici.

Once released in the environment, engineered nanoparticles (NPs) can undergo important transformation resulting in changed properties under natural conditions. This study investigated the fate, the bioavailability and the immunotoxicity of cerium oxide (CeO2) nanoparticles in fish exposed to CeO2 in representative surface waters differing in pH, organic matter content and conductivity (green and brown waters). Following an incubation period of NP CeO2 in different surface waters, particle size distribution and shape were determined by ultrafiltration and ICP-mass spectrometry, electronic microscopy and dynamic light scattering (DSL). Bioaccumulation and effect biomarkers focusing on the immune system responses (viability of immune cells and phagocytic activity) were also determined. Particle size distributions significantly changed under all types of surface waters where aggregation of NPs was commonly observed. Indeed, >90% of NPs CeO2 were found as aggregates (>450 nm) and large colloids (>100 nm). Less than 1% cerium (Ce) was found in the truly dissolved fraction (<1 kDa) suggesting no evidence of degradation for NP CeO2 in the water samples after 96 h. The NPs CeO2 were preferably accumulated in fish gills and accumulation was the highest in green waters which contained less total organic carbon (TOC), higher conductivity (218 μS/cm) and higher pH (7.8-8.0) than brown waters. The toxic properties (induced phagocytosis) of NP CeO2 also differed when dispersed in brown, green and tap waters. NPs CeO2 induced fish mortality at initial concentration of 10 μg/L Ce in both tap and green waters but not in brown waters which have different and high organic matter sources, lower pH and conductivity values. In conclusion, NPs CeO2 tends aggregate in representative freshwater, adsorb on gills and the immunotoxic potential is reduced in the presence of high natural organic matter, mildly acidic pH and low conductivity as found in brown waters.

Increased oil sands (OS) mining activity has raised concerns about impacts on aquatic organisms. This study sought to examine the effects of single representative compounds from OS (benzo(a)pyrene, naphthalene), a mixture of naphthenic acids (NAs), OS-processed water (OSPW) and OS leachate (OSL) extracts on rainbow trout leukocytes. Primary cultures of trout leukocytes were exposed to increasing concentrations of benzo(a)pyrene, naphthalene, NAs, OSPW and OSL for 48h at 18°C. Immunocompetence was followed by measuring changes in lymphocyte and macrophage viability and phagocytosis. Changes in the expression of 10 transcripts were also followed: interleukin 1, 2 and 6 (Il-1, Il-2 and Il-6), calreticulin (CRT), caspase 9 (Cas9), aryl hydrocarbon receptor (AhR), cyclooxygenase-2 (COX2), glutathione S-transferase (GST), catalase (CAT) and p53 tumor suppressor. The results revealed that exposure to OSPW extracts decreased the capacity of macrophages to engulf three beads or more, while the other compounds generally increased phagocytosis activity. Lymphocyte apoptosis was increased by all compounds and mixtures except naphthalene. Both OSPW and OSL induced apoptosis in macrophages. At the gene expression level, Cas9, CRT, Il-1 (inhibition) and Il-2 were specifically influenced by OSPW, while CAT, p53, COX2 and Il-1 (induction) transcripts were specifically expressed by OSL. Leukocyte exposure to OSPW produced characteristic changes in immunocompetence and genes involved in proinflammatory, apoptosis and protein damage (CRT) pathways which could not be explained by OSL, benzo(a)pyrene, naphthalene and NA mixture.

Multi-biological level assessments have become great tools to evaluate the health of aquatic ecosystems. Using this approach, a complementary study was designed to evaluate the health of yellow perch (Perca flavescens) populations in the St. Lawrence River (Quebec, Canada). In the present study, stress responses were compared at the transcriptomic, cellular, and tissue levels in yellow perch collected at six sites along the river: Lake St. François, Lake St. Louis (north and south), Beauregard Island and Lake St. Pierre (north and south). These results complement the physiological and chemical parameters as well as pathogen infection investigated in a companion paper published in the present issue. Thiobarbituric acid reactive substance (TBARS) analyses indicated the presence of oxidative stress in fish collected in the southern part of Lake St. Louis and at the downstream sites of Lake St. Pierre. High lipid peroxidation levels were found in the muscle of yellow perch caught at Beauregard Island, located downstream of the Montreal’s wastewater treatment plant, suggesting an impact of the municipal effluent on redox homeostasis. Transcriptomic results indicated the down-regulation of genes related to lipid, glucose, and retinoid in southern Lake St. Pierre as well as a decrease in retinoid storage. Overall, biochemical and molecular markers indicated that the health status of yellow perch followed a decreasing gradient from upstream to downstream of the St. Lawrence River. This gradient is representative of the cumulative negative impacts of human activities on water and habitat quality along the river.

Silver nanoparticles (AgNPs) are currently used in technology, medicine and consumer products, even though the fate and the ecotoxicological risks on aquatic organisms of these new materials are not well known. The purpose of this study was to investigate the fate, bioavailability of AgNPs and their effects on fish in presence of municipal effluents. Juvenile rainbow trout were exposed for 96 h to 40 μg/L of AgNPs or 4 μg/L of dissolved silver (AgNO3) in diluted (10%) municipal wastewater. Silver (Ag) concentrations were measured both on water samples and fish tissues (liver and gills). Toxicity was investigated by following immunological parameters in the pronephros (viability, phagocytosis) and biomarkers in liver and gills (cyclooxygenase activity, lipid peroxidation, glutathione-S-transferase, metallothioneins, DNA strand breaks and labile zinc). Results indicated that AgNPs appeared as small non-charged aggregates in wastewaters (11.7 ± 1.4 nm). In gills, the exposure to AgNPs induced morphological modifications without visible nanoparticle bioaccumulation. Dissolved Ag+ was bioavailable in diluted effluent and induced oxidative stress (lipid peroxidation), labile zinc and a marginal decrease in superoxide dismutase in fish gills. Ag+ also increased significantly metallothionein levels and inhibited the DNA repair activity in the liver. Finally, the two silver forms were found in liver and induced immunosuppression and inflammation (increase in cyclooxygenase activity). This study demonstrated that both forms of Ag produced harmful effects and AgNPs in wastewater were bioavailable to fish despite of their formation of aggregates.

A multi-disciplinary approach was used to evaluate the health of yellow perch (Perca flavescens) in the St. Lawrence River (Quebec, Canada), which is experiencing a severe population decline in the downstream portion of the river. Physiological parameters, liver alterations, trace metal concentrations, parasite prevalence and abundance, stable isotope composition, and the presence/absence of the viral hemorragic septicemia virus (VHSV) were evaluated in perch collected at six sites along the river: Lake St. François, Lake St. Louis (north and south), Beauregard Island, and Lake St. Pierre (north and south). Trace metal concentrations in surface water were higher in Lake St. Louis and downstream of a major urban wastewater treatment plant discharge, indicating that this effluent was a significant source of Cu, As, Ag, Zn, and Cd. Levels of Pb in surface water exceeded thresholds for the protection of aquatic life in Lake St. Louis and were negatively correlated with body condition index in this lake. In Lake St. Pierre, Cu, Ag, and Cd bioaccumulated significantly in perch liver and lower body condition index and greater liver damage were observed compared to upstream sites. Parasite analyses indicated a higher abundance of metacercariae of the trematodes Apophallus brevis and Diplostomum spp. in Lake St. Louis, and VHSV was not detected in the liver of yellow perch for all studied sites. Overall, results suggested that the global health of yellow perch from Lake St. Pierre is lower compared to upstream studied sites, which could contribute to the documented population collapse at this site.

The increasing use of products derived from nanotechnology has raised concerns about their potential toxicity, especially at the immunocompetence level in organisms. This study compared the immunotoxicity of cadmium sulfate/cadmium telluride (CdS/Cd‐Te) mixture quantum dots (QDs) and their dissolved components, cadmium chloride (CdCl2)/sodium telluride (NaTeO3) salts, and a CdCl2/NaTeO3 mixture on four animal models commonly used in risk assessment studies: one bivalve (Mytilus edulis), one fish (Oncorhynchus mykiss), and two mammals (mice and humans). Our results of viability and phagocytosis biomarkers revealed that QDs were more toxic than dissolved metals for blue mussels. For other species, dissolved metals (Cd, Te, and Cd‐Te mixture) were more toxic than the nanoparticles (NPs). The most sensitive species toward QDs, according to innate immune cells, was humans (inhibitory concentration [IC50] = 217 μg/mL). However, for adaptative immunity, lymphoblastic transformation in mice was decreased for small QD concentrations (EC50 = 4 μg/mL), and was more sensitive than other model species tested. Discriminant function analysis revealed that blue mussel hemocytes were able to discriminate the toxicity of QDs, Cd, Te, and Cd‐Te mixture (Partial Wilk's λ = 0.021 and p < 0.0001). For rainbow trout and human cells, the immunotoxic effects of QDs were similar to those obtained with the dissolved fraction of Cd and Te mixture. For mice, the toxicity of QDs markedly differed from those observed with Cd, Te, and dissolved Cd‐Te mixture. The results also suggest that aquatic species responded more differently than vertebrates to these compounds. The results lead to the recommendation that mussels and mice were most able to discriminate the effects of Cd‐based NPs from the effects of dissolved Cd and Te at the immunocompetence level. © 2013 Wiley Periodicals, Inc. Environ Toxicol 30: 9–25, 2015.

The exploitation of oil sands has raised major environmental concerns, particularly regarding the presence of high concentration in contaminants such as polycyclic aromatic hydrocarbons (PAHs) and naphthenic acids (NAs) in oil sands process-affected water (OSPW). The purpose of this study was, first to evaluate the genotoxic impact of OSPW-related compounds such as NAs and PAHs in a salmonid species and secondly to assess if OSPW exposure leads to genotoxicity. For this purpose, rainbow trout hepatocytes were exposed in vitro to environmentally relevant concentrations of synthetic NAs, naphtalene, benzo(a)pyrene, and extracts of synthetic OSPW (generated by a laboratory bitumen extraction) and of oil sands leaching water (OSLW, mimicking leaching of oil sands in river water). Primary DNA damage was assessed by the formamidopyrimidine-DNA glycolyase (Fpg)-modified comet assay. Genotoxicity was observed in hepatocytes exposed to several NAs, mixture of them, OSPW and OSLW extracts. The chemical structure of NAs influences the genotoxicity potential: among the NAs tested, the most cyclic NA was the most genotoxic. It also appears that genotoxicity was more marked for OSPW than for OSLW. Because exposure to OSPW led to oxidative DNA damage, while after exposure to several NAs, these types of DNA damage were limited, the NAs tested in this study could not be qualified as the only major contaminants responsible for OSPW genotoxicity. Notwithstanding, it should be noteworthy that exposure to NAs resulted in genotoxic impact at concentrations lower than those documented by literature for fresh OSPW. Further research is needed to explore the relationships between the chemical structure of NAs and their genotoxicity in the light of the distribution of NAs in fresh OSPW samples as well as in surface waters.

Many surface waters have been reported to be contaminated whereas the most critical sources remain to be identified. [...]

The purpose of this study was to examine the effects of Ag nanoparticles (nAg) of two different sizes (20 and 80 nm) and Ag+ on the immune system of the freshwater mussel Elliptio complanata. Mussels were exposed to increasing concentrations of nAg and dissolved Ag (AgNO3) for 48 h at 15°C and concentration of 0, 0.8, 4, or 20 μg/L. Immunocompetence was determined by hemocyte viability, phagocytosis, and cell cytotoxicity. Ag tissue loadings and levels of metallothioneins (MT), lipid peroxidation (LPO), and labile zinc (Zn) were also determined. Results revealed first that 20- and 80-nm nAg readily formed aggregates in freshwater. Ag was detected in soft tissues with each form of Ag with bioconcentration factors of 20, 9, and 7 for Ag+, 20-nm nAg, and 80-nm nAg, respectively. Significant induction in phagocytosis and decreased cell cytotoxicity were observed. All forms of Ag were able to induce LPO in gills and digestive glands at concentrations below those from the initial fraction of dissolved Ag. The effects of nAg on MT levels in mussels were not discernible from those of dissolved Ag, but the 80-nm was 25-fold more potent than 20-nm nAg in inducing MT. Multivariate analysis revealed that the global responses of the 20- and 80-nm nAg were generally similar to those of dissolved Ag. Data also demonstrated that nAg are bioavailable for mussels where the immune system is a target during early exposure to nanoparticles.

Effects of simultaneous exposure of Pacific oyster, Crassostrea gigas, to both a harmful dinoflagellate that produces Paralytic Shellfish Toxins (PST), Alexandrium minutum, and cadmium (Cd) and copper (Cu), were assessed. Oysters were exposed to a mix of Cd-Cu with two different diets (i.e. A. minutum or Tisochrysis lutea) and compared to control oysters fed A. minutum or T. lutea, respectively, without metal addition. Metals and PST accumulations, digestive gland lipid composition, and cellular and biochemical hemolymph variables were measured after 4 days of exposure. Oysters exposed to Cd-Cu accumulated about thirty-six times less PSTs than oysters exposed to A. minutum alone. Exposure to Cd-Cu induced significant changes in neutral lipids (increase in diacylglycerol - DAG - and decrease in sterols) and phospholipids (decreases in phosphatidylcholine, phosphatidylethanolamine, cardiolipin and ceramide aminoethylphosphonate) of digestive gland suggesting that lipid metabolism disruptions and/or lipid peroxidation have occurred. Simultaneously, concentrations, percentages of dead cells and phenoloxidase activity of hemocytes increased in oysters exposed to metals while reactive oxygen species production of hemocytes decreased. Feeding on the harmful dinoflagellate A. minutum resulted in significant decreases in monoacylglycerol (MAG) and DAG and ether glycerides (EG), as well as significant increases in hemocyte concentration and phagocytic activity as compared to oysters fed T. lutea. Finally, the present study revealed that short-term, simultaneous exposure to Cd-Cu and A. minutum may induce antagonistic (i.e. hemocyte concentration and phagocytosis) or synergic (i.e. DAG content in digestive gland) effects upon cellular and tissular functions in oysters. (C) 2013 Elsevier B.V. All rights reserved.

The increasing use of products derived from nanotechnology has raised concern about their potential toxicity to aquatic life. This study sought to examine the comparative immunotoxicity of capped cadmium sulphide/cadmium telluride (CdS/CdTe) quantum dots (QDs) and possible impact of particle/aggregate size on two bivalves (Mytilus edulis and Elliptio complanata) and a fish (Oncorhynchus mykiss). The QDs were dispersed in sterile water and fractionated using a series of micro/ultrafiltration membranes of decreasing pore size: 450 nm, 100 nm, 50 nm, 25 nm, 100 kDa (6.8 nm), 30 kDa (4.6 nm), 10 kDa (3.2 nm) and 1 kDa (1.5 nm). The total concentrations of cadmium and tellurium were determined for the filtered material and for that retained on the filters (retentate). The immunotoxicity was determined by measuring cell viability and phagocytosis. Results revealed that nanoparticles retained on the ultrafilters had a higher Cd/Te ratio compared to the permeate fraction (ratio of 5 and 2 respectively) which could indicate that the CdS core was not associated with the permeable fraction of Cd. Our results demonstrate that the toxicity of CdS/CdTe QDs was concentration and size dependent. Large CdS/CdTe QD aggregates (25 nm < size < 100 nm) reduced phagocytosis more than did smaller nanoparticles (<25 nm). Moreover, our results revealed that the different species responded differently to these fractions. Mytilus edulis hemocytes were less sensitive to CdS/CdTe QDs than the Oncorhynchus mykiss macrophage and Elliptio complanata hemocytes.

A l'heure actuelle, l'usage des nanoparticules est de plus en plus mediatise. Elles sont maintenant utilisees a grande echelle et sont presentes dans tous les domaines : biologie, medecine, ingenierie, optique, electronique, mecanique, chimie, pharmacologie, cosmetique. Les nanoparticules sont utilisees en raison de leurs proprietes specifiques. Dans le domaine medical, par exemple, les nanoparticules de Cd/S Cd/Te aussi nommees quantum dots (QDs) sont utilisees comme sondes fluorescentes. Quant aux nanoparticules d'argent (AgNPs), elles sont principalement employees pour leurs proprietes antimicrobiennes. Cependant, de recentes etudes ont demontres que ces nanoparticules induisent une certaine toxicite. Malheureusement, peu de recherches ont ete realisees sur les nanoparticules et le systeme immunitaire. L'objectif principal de cette these etait donc d'evaluer l'immunotoxicite des nanoparticules de Cd/S, Cd/Te et d'Ag sur des especes modeles. Dans le cadre de ces travaux, nous avons defini quatre sous-objectifs: 1) determiner l'impact des nanoparticules sur differentes cellules et systemes immunitaires; 2) evaluer les facteurs influencant la toxicite des nanoparticules; 3) identifier les atteintes mecanistiques de la reponse immunitaire 4) etablir la toxicite des nanoparticules en fonction des stress environnementaux. Afin d'evaluer la toxicite des ces materiaux emergents nous avons choisi d'etudier in vitro les performances du systeme immunitaire de quatre modeles d'animaux: l'humain, la souris (Mus musculus), la truite arc en ciel (Oncorhynchus mykiss) et la moule (Mytilus edulis). Ces especes ont ete definies car elles representent des especes sentinelles de leur milieu de vie. Ainsi, ces especes sont souvent utilisees dans des etudes ecotoxicologiques ou dans les etudes de risques. Dans un premier temps, nous devions determiner l'impact de ces contaminants emergents sur les performances du systeme immunitaire. Les resultats des differents parametres immunitaires ont demontres que les nanoparticules induisent des alterations des performances du systeme immunitaire. Selon les especes, les nanoparticules (QDs et d'AgNPs) induisent une immunostimulation ou une immunosuppression. Le modele mammifere semble etre le plus sensible aux NPs. D'autre part, nos resultats ont mis en evidence le fait que les NPs n'induisent pas toutes la meme toxicite, les AgNPs sont plus toxiques que les QDs. Finalement, nos resultats ont demontre qu'il existait une gradation de la toxicite des nanoparticules en fonction des especes exposees. Dans un deuxieme temps, nous devions determiner si la toxicite des nanoparticules etait influencee par leur chimie, par la nature du metal les composants et par leurs tailles. Nos experiences ont permis de demontrer que les NPs ne sont pas stables dans les differents milieux de cultures utilises pour chacun des modeles d'animaux. Elles sont stables dans l'eau sterile, dans le RPMic et RPMic sans bicarbonate. Toutefois, elles se desagregent dans l'eau de mer. D'autre part, notre etude a demontre que les NPs non transformees (celles qui ne subissent pas de filtration etc.) sont intemalisees entierement dans les cellules. Selon les especes, les metaux dissous contenus dans la particule sont plus toxiques que la NP attestant une certaine stabilite de la particule. De plus, la taille joue un role dans la toxicite des QDs. Les resultats obtenus par ultrafiltration attestent que les particules de grosses tailles sont plus toxiques que celles de petites tailles. Ces dernieres, quant a elles, induisent des phenomenes de stimulation du systeme immunitaire a faible dose plus communement appele phenomene d'hormese. Dans un troisieme temps, nous devions evaluer les mecanismes de defense de la cellule lors d'expositions in vitro au NPs. Les resultats ont montre une production de thiols a faible dose de QDs et une diminution a fortes concentrations. Ceci suggere que les nanoparticules induisent un stress oxydatif, qui a forte dose n'est plus controle par la cellule. De meme, il a ete observe que de fortes concentrations de QDs induisent la production des metallothioneines. Cela pourrait etre attribue au relargage des ions metalliques toxiques contenus dans le noyau de la particule. D'autre part, les resultats obtenus en imagerie electronique et confocale nous ont permis d'affirmer que les QDs et AgNPs induisent des phenomenes d'apoptose et de necrose chez les cellules immunitaires. Dans un quatrieme temps, nous devions determiner si une exposition aux contaminants naturels modulait la toxicite des nanoparticules chez la moule bleue. Ces etudes in vitro ont ete realisees a la fois dans des sites choisis en France et au Quebec. Les resultats obtenus ont demontre que des organismes deja sensibilises par leur milieu de vie sont encore plus sensibles a une exposition aux NPs. Par ailleurs, lors de phenomene « stress on stress » des NPs non toxiques au laboratoire deviennent toxiques a forte dose lors d'experience de terrain. Finalement, ces experiences ont contribue a une meilleure connaissance de la toxicite des NPs selon differents modeles d'etudes. Elles ont apporte beaucoup de renseignements sur les performances des systemes immunitaires de differents modeles d'animaux. Ceci a permis d'evaluer la sensibilite de chaque espece et de classer celles-ci selon les risques d'exposition. D'autre part, l'utilisation de nanoparticules commerciales et le volet de caracterisation chimique de la these ont permis de mieux evaluer les reels enjeux lies aux particules. Les resultats concernant la sensibilite des differents modeles d'animaux pourront etre utilises dans les prochaines etudes de risques. Dans le futur, il serait interessant de mener plus d'etudes sur la genotoxicite des NPs, sur les processus de metabolisations associes et leur impact sur le developpement du systeme immunitaire.