International audience | The Telesphore project aims to identify and to quantify the transfers of pharmaceuticals residues and biocides and their related processes from biosolids and manure spread on grassland as fertilizers. Real land-spreading conditions were reproduced on six in-situ lysimeters and the pathway of pharmaceuticals and biocides was tracked by sampling infiltrated water and soil over one year. The study has focused on 32 pharmaceuticals, biocides and their transformation products, selected from their previous detection in several organic fertilizers. Six months after biosolids and manure spreading, the soil concentrations were in the range of nanograms per gram of soil and only few compounds were detected in infiltrated water. Ketoprofen was found to be the most mobile and persistent pharmaceutical compound after biosolids application whereas thiabendazole was the most frequently detected substance in infiltrated water after manure amendment.

International audience | We used the Ecopath with Ecosim ecosystem model to assess the future effects of multiple stressors on sardine and the Portuguese continental shelf ecosystem. We assessed individual and combined impacts of changes insardine fishing pressure, biomass of sardine competitors and predators and sea surface temperature (SST). This study demonstrated that the greatest impact on sardine stock is caused by projected SST rise whose effect isdominant and detrimental to sardine stock regardless of other conditions, including sardine fishing at maximum sustainable yield (FMSY). The largest impact on ecosystem stability, maturity and diversity of flows was observedunder the forced-biomass scenarios that simulate changes in biomass of sardine predators and competitors. Moreover, these stressors alongside FMSY are projected to play an important role in the future evolution of thesardine stock. Results presented in this study can assist long-term and strategic management of the Iberian sardine stock

International audience | A novel heavy metal resistant actinobacterial strain was isolated from an old lead and zinc mine in north-eastern Algeria. This strain was shown to resist high concentrations of heavy metals, including up to 500 ppm arsenic, 700 ppm cadmium, 1750 ppm chromium, 1250 ppm cobalt, 1000 ppm copper, 2750 ppm iron, 2750 ppm lead, 800 ppm mercury, 1750 ppm nickel, and 2750 ppm zinc. In addition, it was able to degrade dyes of the most used families, i.e., triphenylmethane (Malachite Green), azo (Ponceau S), and anthraquinone (Remazol Brilliant Blue R) dyes at 97.79%, 62.93%, and 39.41%, respectively. This bacterium was identified by sequencing the 16S rRNA encoding gene and affiliated to the genus Streptomyces by the RDP Naive Bayesian rDNA Classifier Version 2.11. The genome of Streptomyces sp. KY75 was sequenced using Illumina MiSeq and Oxford Nanopore. It was annotated by the MicroScope platform, and gene codings for resistance to heavy metals and dye biodecolorization were identified. It has a single linear chromosome with 7,837,660 bp and a GC content of 71.58%, 7509 of coding sequences (CDS), 66 tRNA genes, 18 rRNA genes, and 11 pseudogenes. The effect of hexavalent chromium on the dye biodegradation in liquid medium was also tested. Surprisingly, the dye biodegradation was not affected by the addition of hexavalent chromium. These observations make the actinobacterial strain Streptomyces sp. KY75 a good candidate for the bioremediation of textile dyeing industry effluents.

International audience | The effect of wastewater irrigation on the diversity and composition of bacterial communities of soil mesocosms planted with lettuces was studied over an experiment made of five cultivation campaigns. A limited effect of irrigation with either raw or treated wastewater was observed in both alpha-diversity and beta-diversity of soil bacterial communities. However, the irrigation with wastewater fortified with a complex mixture of fourteen relevant chemicals at 10 mu g/L each, including pharmaceutical, biocide, and pesticide active substances, led to a drift in the composition of soil bacterial community. One hundred operational taxonomic units (OTUs) were identified as responsible for changes between treated and fortified wastewater irrigation treatments. Our findings indicate that under a realistic agronomical scenario, the irrigation of vegetables with domestic (treated or raw) wastewater has no effect on soil bacterial communities. Nevertheless, under the worst-case scenario tested here (i.e., wastewater fortified with a mixture of chemicals), non-resilient changes were observed suggesting that continuous/repeated irrigation with wastewater could lead to the accumulation of contaminants in soil and induce changes in bacterial communities with unknown functional consequences.

International audience

International audience | The implementation of Nature-based Solutions (NBS) in cities has shifted to an integrated approach paradigm, raising the need for a shared, explicit and formal representation of knowledge on NBS in urban water management. A solution is building an ontology: it is a representation that merges data and expert knowledge, prevents miscommunication, handles heterogeneous data types and formats, and can draw inferences. The ontology we present here was focused on describing a water treatment chain (core ontology), classifying NBS (notably Treatment Wetlands (TW)) and treatment mechanisms. Its construction has mobilized expert knowledge, existing ontologies and explicitation of relations between concepts, sometimes from different knowledge domains: technical, geographical, socio-environmental. The ontology is not only for description of NBS in urban water management, but also for better future database structuration and modelling purposes (for predictions in a decision-making support tool). The ontology will improve from iterative expert feedback.

International audience | In 2020 two main French research institutes, INRA and IRSTEA, merged to form INRAE the French National Research Institute for Agriculture, Food and Environment. This was a timely opportunity to update the ecotoxicology delineations and to identify new key issues to be developedat INRAE, notably by including aquatic ecosystems biodiversity and public policies as new research priorities, and for the French ECOTOX Network of terrestrial and aquatic ecotoxicology supported by INRAE (https://www6.inrae.fr/ecotox/) to address new research and development topics.Within this context, the ecotoxicology of the soil:water continuum (SWC) was chosen as the theme of the 7th seminar of the ECOTOX Network held as a 2-day webinar in November 2020. This special issue proposes a selection of some of the presented studies, covering subjects from terrestrial to aquatic ecotoxicology, including experimental and modelling approaches, to finally tentatively describe what could stand for SWC ecotoxicology in the Anthropocene context.

The impact of microplastics (MP) has attracted much attention from the scientific community and many laboratory assessments have been made of their effects on aquatic organisms. To produce MP from real environmental plastic waste, which would enable more realistic experiments, we used plastic pearl farming equipment from French Polynesian lagoons. Here, the pearl oyster Pinctada margaritifera could encounter MP coming from their breakdown in its surrounding environment. We tested an established method based on mechanical cryogenic grinding and liquid sieving. Our desired size range was 20–60 μm, corresponding to the optimal particle size ingested by P. margaritifera. The protocol was effective, generating MP particles of 20–60 μm (∼17,000–28,000 MP μg−1), but also produced too many smaller particles. The peak in the desired size range was thus flattened by the many small particles <3 μm (∼82,000–333,000 MP μg−1; 53–70% of total analysed particles), visible at the limit of Coulter counter analysis (cut-off point: 2 μm). Laser diffraction analysis (cut-off point: 0.4 μm) provided greater detail, showing that ∼80–90% of the total analysed particles were <1 μm. Diverging particle size distributions between those expected based on sieving range and those really observed, highlight the need to perform fine-scaled particle size distribution analyses to avoid underestimating the number of small micro- and nanoplastics (MNP) and to obtain an exact estimation of the fractions produced. Size and microstructure characterization by scanning electron microscopy suggested spontaneous particle self-assembly into crystal superstructures, which is the supposed cause of the divergence we observed. Overall, our results emphasize that particle self-assembly is a technical hurdle requiring further work and highlight the specific need to finely characterize the size distribution of MNP used in ecotoxicological experiments to avoid overestimating effects.