International audience | Shipping noise is a threat to marine wildlife. Grey seals are benthic foragers, and thus experience acoustic noise throughout the water column, which makes them a good model species for a case study of the potential impacts of shipping noise. We used ship track data from the Celtic Sea, seal track data and a coupled ocean-acoustic modelling system to assess the noise exposure of grey seals along their tracks. It was found that the animals experience step changes in sound levels up to ~20dB at a frequency of 125Hz, and ~10dB on average over 10 1000Hz when they dive through the thermocline, particularly during summer. Our results showed large seasonal differences in the noise level experienced by the seals. These results reveal the actual noise exposure by the animals and could help in marine spatial planning. 2

International audience | The influence of atmospheric phenanthrene (PHE) exposure (160 mgm 3) during one month on carbon allocation in clover was investigated by integrative (plant growth analysis) and instantaneous 13CO2 pulse-labelling approaches. PHE exposure diminished plant growth parameters (relative growth rate and net assimilation rate) and disturbed photosynthesis (carbon assimilation rate and chlorophyll content), leading to a 25% decrease in clover biomass. The root-shoot ratio was significantly enhanced (from 0.32 to 0.44). Photosynthates were identically allocated to leaves while less allocated to stems and roots. PHE exposure had a significant overall effect on the 13C partitioning among clover organs as more carbon was retained in leaves at the expense of roots and stems. The findings indicate that PHE decreases root exudation or transfer to symbionts and in leaves, retains carbon in a non-structural form diverting photosynthates away from growth and respiration (emergence of an additional C loss process).

International audience | Polycyclic aromatic hydrocarbon (PAH) concentrations and N, C stable isotope signatures were determined in mosses Hypnum cupressiforme Hedw. from 61 sites of 3 European regions: Île-de-France (France); Navarra (Spain); the Swiss Plateau and Basel area (Switzerland). Total PAH concentrations of 100-700 ng g-1, as well as δ13C values of -32 to -29‰ and δ15N values of -11 to -3‰ were measured. Pearson correlation tests revealed opposite trends between high molecular weight PAH (4-6 aromatic rings) content and δ13C values. Partial Least Square regressions explained the very significant correlations (r > 0.91, p < 0.001) between high molecular weight PAH concentrations by local urban land use (<10 km) and environmental factors such as elevation and pluviometry. Finally, specific correlations between heavy metal and PAH concentrations were attributed to industrial emissions in Switzerland and road traffic emissions in Spain.

International audience | Urban streams that receive untreated domestic and hospital waste can transmit infectious diseases and spread drug residues, including antimicrobials, which can then increase the selection of antimicrobial-resistant bacteria. Here, water samples were collected from three different urban streams in the state of São Paulo, Brazil, to relate their range of Water Quality Indices (WQIs) to the diversity and composition of aquatic microbial taxa, virulence genes (virulome), and antimicrobial resistance determinants (resistome), all assessed using untargeted metagenome sequencing. There was a predominance of phyla Proteobacteria, Actinobacteria, and Bacteroidetes in all samples, and Pseudomonas was the most abundant detected genus. Virulence genes associated with motility, adherence, and secretion systems were highly abundant and mainly associated with Pseudomonas aeruginosa. Furthermore, some opportunistic pathogenic genera had negative correlations with WQI. Many clinically relevant antimicrobial resistance genes (ARGs) and efflux pump-encoding genes that confer resistance to critically important antimicrobials were detected. The highest relative abundances of ARGs were β-lactams and macrolide-lincosamide-streptogramin. No statistically supported relationship was detected between the abundance of virulome/resistome and collection type/WQI. On the other hand, total solids were a weak predictor of gene abundance patterns. These results provide insights into various microbial outcomes given urban stream quality and point to its ecological complexity. In addition, this study suggests potential consequences for human health as mediated by aquatic microbial communities responding to typical urban outputs.

International audience | The bioavailability of trace elements (As, Cd, Co, Cr, Cu, Hg, Ni, Pb, Zn) in lowly to moderately contaminated coastal sediments from the Berre lagoon, France, was assessed by comparing their potentially bioavailable concentrations and bioaccumulated concentrations in the polychaete Alitta succinea. No linear correlations were observed contrarily to what is generally observed in similar works in areas with highly contaminated sediment. Correlations between trace and major elements (Fe, Ca, S, Mg, P, Al) in Alitta succinea tissues and their distribution in organism tissues show that, in such lowly to moderately contaminated sediments, biological variabilities should be considered. Normalization procedures allow to take into account these variabilities and to identify that sediment contamination is partly involved in the benthic ecosystem degradation of the Berre lagoon. Alitta succinea cannot be used as relevant bioindicator for Zn and Co bioavailability in sediment, since these elements are regulated by this organism.

International audience | Revegetation of abandoned aquaculture regions should be a priority for any integrated coastal zone management (ICZM). This paper examines the potential of a matchless time series of 20 very high spatial resolution (VHSR) optical satellite images acquired for mapping trends in the evolution of mangrove forests from 2001 to 2015 in an estuary fragmented into aquaculture ponds. Evolution of mangrove extent was quantified through robust multitemporal analysis based on supervised image classification. Results indicated that mangroves are expanding inside and outside ponds and over pond dykes. However, the yearly expansion rate of vegetation cover greatly varied between replanted ponds. Ground truthing showed that only Rhizophora species had been planted, whereas natural mangroves consist of Avicennia and Sonneratia species. In addition, the dense Rhizophora plantations present very low regeneration capabilities compared with natural mangroves. Time series of VHSR images provide comprehensive and intuitive level of information for the support of ICZM.

Intensified treatment wetlands can reduce treatment wetlands footprint, improve efficiencies and deal with unusual influent characteristics. A specific design of 750 p.e. has been implemented for a highway rest area in France.