Changes in copper toxicity towards diatom communities with experimental warming
Variations de la toxicité du cuivre en fonction d'une hausse expérimentale de température, vis-à-vis des communautés de diatomées
Morin, S. ; Lambert, A.S. ; Planes Rodriguez, E. ; Dabrin, A. ; Coquery, M. ; Pesce, S.
Type de document
Article de revue scientifique à comité de lecture
Affiliation de l'auteur
IRSTEA BORDEAUX UR EABX FRA ; IRSTEA LYON UR MALY FRA ; IRSTEA BORDEAUX UR EABX FRA ; IRSTEA LYON UR MALY FRA ; IRSTEA LYON UR MALY FRA ; IRSTEA LYON UR MALY FRA
Résumé / Abstract
Biological communities in aquatic environments most commonly face multiple stress, where natural andanthropogenic stressors often act jointly. Their interactions are most easily assessed using short cycleorganisms such as periphytic diatoms.In this experiment, we analyzed the combined effects of copper exposure and warming on diatomsuccessions over 6 weeks. Natural biofilm collected in winter was left to grow in mesocosms exposed orunexposed to realistic Cu concentrations at four different temperatures. Separate and joint impacts ofthe two stressors were determined through structural and functional endpoints.Both temperature and copper influenced the biological responses; their interaction, when significant,was always antagonistic. Diatom communities gradually changed with rising temperature. Under copperexposure, the dominant Planothidium lanceolatum was superseded by Achnanthidium exiguum, whichaccounted for about 70% relative abundance in the warmest conditions (18–23◦C). Tolerance to copperwas derived from dose-response curves based on photosynthesis inhibition. Cu-induced communitytolerance was always found, but it decreased with warming and time.Biodiversity loss associated with lower Cu tolerance under combined Cu exposure and increasing tem-peratures evidences the major influence of cumulative stressors on aquatic health. These results highlightthe crucial interplay between environmental stressors, which are expected to intensify with climatechange.
Journal of Hazardous Materials, vol. 334, p. 223 - 232