Benthic macroinvertebrate diversity and function in an agricultural constructed wetland affected by agrochemical pressure (Seine-et-Marne, France)
2025
Michel, Alexandre | Lebrun, Jérémie | Chaumont, Cédric | Girondin, Mathieu | Tournebize, Julien | Archaimbault, Virginie | Jeliazkov, Alienor | Hydrosystèmes continentaux anthropisés : ressources, risques, restauration (UR HYCAR) ; Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | This work was supported by INRAE Metaprogramme BIOSEFAIR. This work was led by the Ministries for Agriculture and Food Sovereignty, for an Ecological Transition and Territorial Cohesion, for Health and Prevention, and of Higher Education and Research, with the financial support of the French Office for Biodiversity, as part of the call for “National research projects Ecophyto 2020 Part 2,” with the fees for diffuse pollution coming from the Ecophyto II + plan. This work was supported by the national Water Agency of Seine-Normandy (Agence de l’Eau Seine-Normandie). The Fédération d’Ile-de-France pour la Recherche en Environnement (FIRE FR-3020) is also greatly acknowledged for its financial support. This work was partly supported by Horizon Europe funding by HORIZON Research and Innovation Actions: Project 101056844 — ALFAwetlands (Wetlands Restoration for the future, https://alfawetlands.eu/).
International audience
显示更多 [+] 显示较少 [-]英语. Constructed wetlands (CWs), originally designed to mitigate chemical water pollution, often host noticeable aquatic fauna. However, little is known about the impact of the contaminants circulating within CWs on this local fauna, questioning the role of CWs as ecological refuges or traps. We aimed to assess the potential of an agricultural CWs in northern France to act as an ecological trap for aquatic fauna and the potential consequences on wetland functioning. We made faunistic inventories of benthic macroinvertebrates, using litterbags, from March to June 2022 in two zones within the CWs with contrasting levels of agrochemical contamination and in one unpolluted comparison pond. We calculated community diversity and sensitivity indices (e.g., species at risk, SPEARpesticides index). We measured wetland functioning by monitoring the leaf-litter breakdown. Results showed that pesticide fluxes were related to community composition changes and had negative effects on taxonomic diversity (Shannon index) and functional traits (shredder/scraper feeding mode). The negative link between pesticides and the leaf-litter breakdown was less clear, mainly because of the high level of integration of this response. This study reveals that CWs under agrochemical pressure may act as potential ecological traps for benthic macroinvertebrates and highlights the relevance of studying this group as an early-warning indicator of chemical risk in nature-based solutions.
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