International audience | Pesticides are often found at high concentrations in small ponds near agricultural field where amphibians are used to live and reproduce. Even if there are many studies on the impacts of phytopharmaceutical active ingredients in amphibian toxicology, only a few are interested in the earlier steps of their life cycle. While their populations are highly threatened with extinction. The aim of this work is to characterize the effects of glyphosate and its commercial formulation Roundup® GT Max on the Xenopus laevis oocyte maturation which is an essential preparation for the laying and the fertilization. Glyphosate is an extensively used herbicide, not only known for its effectiveness but also for its indirect impacts on non-target organisms. Our results showed that exposures to both forms of glyphosate delayed this hormone-dependent process and were responsible for spontaneous maturation. Severe and particular morphogenesis abnormalities of the meiotic spindle were also observed. The MAPK pathway and the MPF did not seem to be affected by exposures. The xenopus oocyte is particularly affected by the exposures and appears as a relevant model for assessing the effects of environmental contamination.

International audience | Amphibians are now recognized as the most endangered group. One of this decline causes is the degradation of their habitat through direct contamination of water, soil leaching, or runoff from surrounding contaminated soils and environments. In the North of France, the extensive industrial activities resulted in massive soil contamination by metal compounds. Mineral amendments were added to soils to decrease trace metal mobility. Because of the large areas to be treated, the use of inexpensive industrial by-products was favored. Two types of fly ashes were both tested in an experimental site with the plantation of trees in 2000. Aim of the present work was to investigate the effects of extracts from metal-contaminated soils treated or not for 10 years with fly ashes on Xenopus laevis oocyte using cell biology approaches. Indeed, our previous studies have shown that the Xenopus oocyte is a relevant model to study the metal ion toxicity. Survival and maturation of oocyte exposed to the soil extracts were evaluated by phenotypic approaches and electrophysiological recordings. An extract derived from a metal-contaminated soil treated for 10 years with sulfo-calcic ashes induced the largest effects. Membrane integrity appeared affected and ion fluxes in exposed oocytes were changed. Thus, it appeared that extracted elements from certain mineral amendments used to prevent the mobility of metals in the case of highly metal-contaminated soils could have a negative impact on X. laevis oocytes.

International audience | Pesticides are often found at high concentrations in small ponds near agricultural field where amphibians are used to live and reproduce. Even if there are many studies on the impacts of phytopharmaceutical active ingredients in amphibian toxicology, only a few are interested in the earlier steps of their life cycle. While their populations are highly threatened with extinction. The aim of this work is to characterize the effects of glyphosate and its commercial formulation Roundup® GT Max on the Xenopus laevis oocyte maturation which is an essential preparation for the laying and the fertilization. Glyphosate is an extensively used herbicide, not only known for its effectiveness but also for its indirect impacts on non-target organisms. Our results showed that exposures to both forms of glyphosate delayed this hormone-dependent process and were responsible for spontaneous maturation. Severe and particular morphogenesis abnormalities of the meiotic spindle were also observed. The MAPK pathway and the MPF did not seem to be affected by exposures. The xenopus oocyte is particularly affected by the exposures and appears as a relevant model for assessing the effects of environmental contamination.

International audience | Because they are widely used, copper oxide nanoparticles (CuO NPs) are likely to enter the aquatic environment and then reach the sediment. We have examined the effect of CuO NPs in the freshwater endobenthic bivalve Corbicula fluminea. Some previous studies have investigated effects at biochemical and physiological levels, but molecular endpoints are still poorly studied despite they are sensitive in early detection of NPs effect. In the present study, we have investigated short-term effects (96 h) of CuO NP (12, 30 nm; 0, 20 and 100 mg/L) using molecular endpoints as well as more conventional biochemical and physiological markers. The expression of antioxidant (CuZnSOD, MnSOD, Cat, Se-GPx, Trxr) and antitoxic (GST-Pi, HSP70, MT, Pgp, MRP1) related genes was measured at the mRNA level while anti-oxidant (SOD, TAC) and antitoxic (GST, ACP) defenses, energetic reserves and metabolism (ETS, Tri, LDH), and cellular damages (LPO) were assessed using a biochemical approach. The filtration rate measured at 96 h provided information at the physiological scale. Gene expression and filtration rate were responsive to CuO NPs but the effects differed according to the NP size. The results suggest that defense mechanisms may have been set up following 30 nm-NP exposure. The response to 12 nm-NP was lower but still showed that exposure to 12 nm-NP led to activation of cellular elimination mechanisms. The lowering of the filtration rate may have protected the organisms from the contamination. However, this raised the question of further repercussions on organism biology. Together, the results (i) indicate that CuO NP may exert effects at different levels even after a short-term exposure and (ii) point out the precocity of molecular response.

International audience | Four perfluoroalkyl substances (PFAS) were analyzed in 62 duplicate surface water samples from the Rhône River and Marseille Bay (France; NW Mediterranean Sea). Perfluorooctane sulfonate (PFOS) was detected in all samples and exceeded the European Environmental Quality Standard (EQS) values in over 80% of the cases. The most contaminated samples were from the Rhône River (up to 200 ng L-1 ∑ 4 PFAS), as well as those collected near a wastewater treatment plant outlet in Marseille Bay (up to 9 ng L −1 ∑ 4 PFAS). While PFOS was the predominant PFAS in Marseille Bay, remarkably high concentrations of perfluorohexanoic acid (PFHxA) were measured in the Rhône River (8-193 ng L −1). The relative abundances of individual compounds differed thus significantly between the Rhône River and Marseille Bay, indicating different sources. A simulation made with the MARS3D model showed that PFOS inputs from the Rhône River can enter Marseille Bay at levels > EQS.

The Ephemare project was supported in the period 2015–2018 by JPI Oceans, as one of 4 sister projects in the joint action on ecological aspects of microplastics. Ephemare investigated several issues concerning the ecotoxicological effects of microplastics (MPs) in marine organisms. Ephemare included 16 European Institutions from 10 Countries and was organized into seven, highly complementary Work Packages (WPs) with the aim to elucidate adsorption and release of chemicals to/from MPs, coupled with MP ingestion rates, translocation in different tissues, trophic transfer and egestion, potential toxicological effects and mechanisms of action, as well as real distributions of MPs in marine organisms from several European areas.

International audience | Aquatic wildlife is exposed through trophic transfer of hazardous substances to several threats inducing physiological impairments. We aimed at assessing the impact of contamination in one of the hot spots of pollution along Mediterranean coasts, the gulf of Gabes in Tunisia, on Common tern Sterna hirundo, a piscivorous top predator bird. Firstly, we compared the reproductive effort of breeding adults through clutch size distribution in three sites with different levels of pollution. Then, a battery of genotoxicity and oxidative stress biomarkers was carried out to assess physiological impairments in chicks. While defense mechanisms showed a depletion, lipid peroxidation and genotoxicity increased significantly according to pollution level. The multi-biomarker approach used here, discriminated chicks according to contamination degree of their nesting sites. Increases in genotoxicity and oxidative stress were correlated to a decrease in chick body mass known to lead to long-term impacts on juvenile survival and recruitment in birds.

International audience | Aquatic wildlife is exposed through trophic transfer of hazardous substances to several threats inducing physiological impairments. We aimed at assessing the impact of contamination in one of the hot spots of pollution along Mediterranean coasts, the gulf of Gabes in Tunisia, on Common tern Sterna hirundo, a piscivorous top predator bird. Firstly, we compared the reproductive effort of breeding adults through clutch size distribution in three sites with different levels of pollution. Then, a battery of genotoxicity and oxidative stress biomarkers was carried out to assess physiological impairments in chicks. While defense mechanisms showed a depletion, lipid peroxidation and genotoxicity increased significantly according to pollution level. The multi-biomarker approach used here, discriminated chicks according to contamination degree of their nesting sites. Increases in genotoxicity and oxidative stress were correlated to a decrease in chick body mass known to lead to long-term impacts on juvenile survival and recruitment in birds.

Today, the environmental awareness is leading to the recovery of the solid organic waste and the use of fossil fuels. Methanisation, or anaerobic digestion, is a solution. This process is the transformation of organic matter by bacteria in the absence of oxygen. It allows both the treatment of organic waste and provides two main products biogas and digestate. Digestate is an improved fertilizer that can be used by spreading or composting. Biogas can be used to produce heat or electricity. Biogas production is currently supported by governments of developed countries. In France, the number of installations is gradually increasing (Club Biogaz ATEE, 2011). However, waste used as raw material can potentially be rich in microorganisms. Currently, some questions arise about the potential spread of micro-organisms by this type of process. Among the among the dispersal pathways, the airborne mode of spread is often poorly explored. During the anaerobic process, a few phases seem to be able to cause the aerosolization of microorganisms, for example, the stock of raw materials or digestate handling. In this context, the EMAMET project was realised to provide data on atmospheric emissions from these processes (Bayle et al, 2016). The objectives of this study are to enumerate and describe the airborne microbial community on anaerobic digestor site caracterized by molecular approach. On a quarterly basis, over a one-year period, of the anaerobic digestion of waste water activated sludge has been monitored. For each campaign, four sampling locations have been investigated; the storage area for raw materials, the raw material preparation area, the digestion reactor and the phase separation zone of the digestate. A fifth simple, an outdoor control sampling point was also included.