title: Effects of copper on invertebrate-sediment interactions.
abstract: Toxicants potentially decouple links between biodiversity and ecosystem processes. This study aimed to evaluate how toxicants affect invertebrate bioturbation and decomposition. Effects of copper on functionally distinct macrofaunal species (Asellus aquaticus and Tubifex spp.), decomposition (release of dissolved organic carbon, DOC) and Average Metabolic Response (AMR) and Community Metabolic Diversity (CMD) of bacteria were determined in 5-day microcosm experiments. Bioturbation was assessed as sediment redox potential (Eh) profiles. Concentration-response curves of the functional parameters DOC, and the faunal mediated AMR and CMD in the presence of Tubifex spp. depended on Tubifex spp. survival, i.e. similar EC50 values for both endpoints. In contrast, functional parameters in the presence of A. aquaticus were more sensitive than survival. Sediment Eh-profiles showed that reduced decomposition was caused by reduced sediment reworking by A. aquaticus at sub-lethal copper concentrations. These observations hint at a decoupling of invertebrate community structure and ecosystem functioning upon stress.
authors.affiliation: Aquatic Ecology and Ecotoxicology, Institute for Biodiversity and Ecosystem Dynamics (IBED-AEE), University of Amsterdam, Science Park 904, NL-1098 XH Amsterdam, The Netherlands. E.R.Hunting@uva.nl
authors.forename: E R
authors.initials: ER
authors.lastname: Hunting
authors.forename: C
authors.initials: C
authors.lastname: Mulder
authors.forename: M H S
authors.initials: MH
authors.lastname: Kraak
authors.forename: A M
authors.initials: AM
authors.lastname: Breure
authors.forename: W
authors.initials: W
authors.lastname: Admiraal
mesh_terms: D000818:Animals; D044822:Biodiversity; D003300:Copper / Q000633:toxicity*; D017753:Ecosystem; D019015:Geologic Sediments / Q000737:chemistry; D007448:Invertebrates / Q000502:physiology*; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D014874:Water Pollutants, Chemical; D003300:Copper
keywords: Bioturbation; Copper; Decomposition; Ecosystem functioning; Invertebrates; Sediment