0000000001212135

AUTHOR

Eric Chauvet

Array of microbial indicators, a promise for a better monitoring of pesticide effects on stream biological quality

Visioconférence; National audience; Freshwater contamination by pesticide residues is a major and growing threat to aquatic communities, ecosystem functioning and ultimately human health worldwide. Typical pesticide contamination in agricultural landscapes is characterized by a cocktail of a large number of active compounds and their main transformation products, each of them found at very low and temporally fluctuating concentrations. This makes the quantification of pesticide residues in streams highly challenging and costly by means of grab chemical sampling. Accordingly, it makes also difficult to characterize the chronic exposure of aquatic communities in pesticide-contaminated streams…

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Science Advances

River ecosystems receive and process vast quantities of terrestrial organic carbon, the fate of which depends strongly on microbial activity. Variation in and controls of processing rates, however, are poorly characterized at the global scale. In response, we used a peer-sourced research network and a highly standardized carbon processing assay to conduct a global-scale field experiment in greater than 1000 river and riparian sites. We found that Earth’s biomes have distinct carbon processing signatures. Slow processing is evident across latitudes, whereas rapid rates are restricted to lower latitudes. Both the mean rate and variability decline with latitude, suggesting temperature constrai…

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Development and dissemination to operational stakeholders of integrative tools for chemical and biological measurements in watercourses to monitor the impact of pesticides according to agricultural practices and their evolution

The results of the Impact-CE project highlight the specific contribution of various integrative tools to have a more complete vision of the chemical and biological impact of pesticides on watercourses. In addition to grabe sampling, which gives a quantitative and instantaneous view of contamination, these tools provide more representative information over time, which makes them better tools for prioritising basins that contribute to contamination. They are also more robust for reporting interannual changes in agricultural practices, even if it may remain difficult to dissociate the effect of limited changes in practices from that of significant climatic variations. The results also confirm …

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