title: The relative importance of diet-related and waterborne effects of copper for a leaf-shredding invertebrate.
abstract: Copper (Cu) exposure can increase leaf-associated fungal biomass, an important food component for leaf-shredding macroinvertebrates. To test if this positive nutritional effect supports the physiological fitness of these animals and to assess its importance compared to waterborne toxicity, we performed a 24-day-bioassay in combination with a 2×2 factorial design using the amphipod shredder Gammarus fossarum and a field-relevant Cu concentration of 25 μg/L (n = 65). Waterborne toxicity was negligible, while gammarids fed leaves exposed to Cu during microbial colonization exhibited a near-significant impairment in growth (∼30%) and a significantly reduced lipid content (∼20%). These effects appear to be governed by dietary uptake of Cu, which accumulated in leaves as well as gammarids and likely overrode the positive nutritional effect of the increased fungal biomass. Our results suggest that for adsorptive freshwater contaminants dietary uptake should be evaluated already during the registration process to safeguard the integrity of detritus-based ecosystems.
authors.affiliation: Institute for Environmental Sciences, University of Koblenz-Landau, Fortstraße 7, 76829 Landau/Palatinate, Germany. Electronic address: zubrod@uni-landau.de.
authors.forename: J P
authors.initials: JP
authors.lastname: Zubrod
authors.affiliation: Institute for Environmental Sciences, University of Koblenz-Landau, Fortstraße 7, 76829 Landau/Palatinate, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Englert
authors.affiliation: Institute for Environmental Sciences, University of Koblenz-Landau, Fortstraße 7, 76829 Landau/Palatinate, Germany.
authors.forename: R R
authors.initials: RR
authors.lastname: Rosenfeldt
authors.affiliation: Institute for Environmental Sciences, University of Koblenz-Landau, Fortstraße 7, 76829 Landau/Palatinate, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Wolfram
authors.affiliation: Institute for Environmental Sciences, University of Koblenz-Landau, Fortstraße 7, 76829 Landau/Palatinate, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Lüderwald
authors.affiliation: Institute for Environmental Sciences, University of Koblenz-Landau, Fortstraße 7, 76829 Landau/Palatinate, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Wallace
authors.affiliation: Institute for Environmental Sciences, University of Koblenz-Landau, Fortstraße 7, 76829 Landau/Palatinate, Germany.
authors.forename: N
authors.initials: N
authors.lastname: Schnetzer
authors.affiliation: Institute for Environmental Sciences, University of Koblenz-Landau, Fortstraße 7, 76829 Landau/Palatinate, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Schulz
authors.affiliation: Institute for Environmental Sciences, University of Koblenz-Landau, Fortstraße 7, 76829 Landau/Palatinate, Germany; Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Lennart Hjelms väg 9, 75007 Uppsala, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Bundschuh
mesh_terms: D033304:Amphipoda / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D018533:Biomass; D003300:Copper / Q000032:analysis / Q000378:metabolism* / Q000633:toxicity; D004784:Environmental Monitoring; D005247:Feeding Behavior / Q000187:drug effects; D020387:Food Chain; D005618:Fresh Water / Q000737:chemistry*; D005658:Fungi / Q000254:growth & development* / Q000378:metabolism; D018515:Plant Leaves / Q000187:drug effects / Q000382:microbiology; D018570:Risk Assessment; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000378:metabolism / Q000633:toxicity
chemical_list: D014874:Water Pollutants, Chemical; D003300:Copper
keywords: Dietary exposure; Environmental risk assessment; Leaf litter breakdown; Physiological fitness; Shredder