title: Temperature modulates phototrophic periphyton response to chronic copper exposure.
abstract: Streams located in vineyard areas are highly prone to metal pollution. In a context of global change, aquatic systems are generally subjected to multi-stress conditions due to multiple chemical and/or physical pressures. Among various environmental factors that modulate the ecological effects of toxicants, special attention should be paid to climate change, which is driving an increase in extreme climate events such as sharp temperature rises. In lotic ecosystems, periphyton ensures key ecological functions such as primary production and nutrient cycling. However, although the effects of metals on microbial communities are relatively well known, there is scant data on possible interactions between temperature increase and metal pollution. Here we led a study to evaluate the influence of temperature on the response of phototrophic periphyton to copper (Cu) exposure. Winter communities, collected in a 8 °C river water, were subjected for six weeks to four thermal conditions in microcosms in presence or not of Cu (nominal concentration of 15 μg L(-1)). At the initial river temperature (8 °C), our results confirmed the chronic impact of Cu on periphyton, both in terms of structure (biomass, distribution of algal groups, diatomic composition) and function (photosynthetic efficiency). At higher temperatures (13, 18 and 23 °C), Cu effects were modulated. Indeed, temperature increase reduced Cu effects on algal biomass, algal class proportions, diatom assemblage composition and photosynthetic efficiency. This reduction of Cu effects on periphyton may be related to lower bioaccumulation of Cu and/or to selection of more Cu-tolerant species at higher temperatures.
authors.affiliation: Irstea, UR MALY, Centre de Lyon-Villeurbanne, 5 rue de la Doua, CS 70077, 69626 Villeurbanne Cedex, France. Electronic address: annesophielambert@orange.fr.
authors.forename: Anne Sophie
authors.initials: AS
authors.lastname: Lambert
authors.affiliation: Irstea, UR MALY, Centre de Lyon-Villeurbanne, 5 rue de la Doua, CS 70077, 69626 Villeurbanne Cedex, France. Electronic address: aymeric.dabrin@irstea.fr.
authors.forename: Aymeric
authors.initials: A
authors.lastname: Dabrin
authors.affiliation: Irstea, UR EABX, Centre de Bordeaux, 33612 Cestas, France. Electronic address: soizic.morin@irstea.fr.
authors.forename: Soizic
authors.initials: S
authors.lastname: Morin
authors.affiliation: Irstea, UR MALY, Centre de Lyon-Villeurbanne, 5 rue de la Doua, CS 70077, 69626 Villeurbanne Cedex, France. Electronic address: josiane.gahou@irstea.fr.
authors.forename: Josiane
authors.initials: J
authors.lastname: Gahou
authors.affiliation: Irstea, UR MALY, Centre de Lyon-Villeurbanne, 5 rue de la Doua, CS 70077, 69626 Villeurbanne Cedex, France; Laboratoire d'Écologie Alpine, UMR CNRS 5553, Université Grenoble Alpes, BP 53, 38041 Grenoble Cedex 9, France. Electronic address: arnaud.foulquier@ujf-grenoble.fr.
authors.forename: Arnaud
authors.initials: A
authors.lastname: Foulquier
authors.affiliation: Irstea, UR MALY, Centre de Lyon-Villeurbanne, 5 rue de la Doua, CS 70077, 69626 Villeurbanne Cedex, France. Electronic address: marina.coquery@irstea.fr.
authors.forename: Marina
authors.initials: M
authors.lastname: Coquery
authors.affiliation: Irstea, UR MALY, Centre de Lyon-Villeurbanne, 5 rue de la Doua, CS 70077, 69626 Villeurbanne Cedex, France. Electronic address: stephane.pesce@irstea.fr.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Pesce
mesh_terms: D018533:Biomass; D002734:Chlorophyll / Q000378:metabolism; D000077194:Chlorophyll A; D057231:Climate Change; D003300:Copper / Q000032:analysis* / Q000378:metabolism / Q000494:pharmacology; D000458:Cyanobacteria / Q000378:metabolism / Q000502:physiology; D017377:Diatoms / Q000378:metabolism / Q000502:physiology; D017753:Ecosystem; D045483:Rivers / Q000737:chemistry*; D013696:Temperature; D014871:Water Microbiology; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000378:metabolism / Q000494:pharmacology
chemical_list: D014874:Water Pollutants, Chemical; D002734:Chlorophyll; D003300:Copper; D000077194:Chlorophyll A
keywords: Bioaccumulation; Biofilms; Freshwater; Global change; Microbial ecotoxicology; Multi-stress