title: The effects of zinc on the structure and functioning of a freshwater community: A microcosm experiment.
abstract: A major problem with risk assessment of chemicals is the extrapolation of laboratory single-species toxicity tests, which oversimplify the actual field situation by ignoring species interactions, to natural communities. The authors tested if the bioavailability-normalized 5% hazardous concentration (HC5) estimated from chronic planktonic single-species toxicity data (HC5plankton) for zinc (Zn) is protective for a plankton community and investigated the direct and indirect effects of Zn (at HC5 and HC50) on a freshwater community's structure and function. Microcosms were exposed to 3 different Zn concentrations (background, HC5plankton= 75 μg Zn/L and HC50plankton= 300 μg Zn/L) for 5 wk. The planktonic groups revealed a consistent no-observed-effect concentration for the community of 75 μg Zn/L, similar to or higher than the HC5plankton, thus suggesting its protectiveness in the present study. At 300 μg Zn/L a significant reduction in cladocerans resulted in increases of rotifer, ciliate, and phytoplankton abundance. In addition, the phytoplankton community shifted in dominance from grazing-resistant to edible species. Contrary to the species sensitivity distribution (SSD) prediction, which identified phytoplankton as the most sensitive group, only the total chlorophyll and the abundance of 2 phytoplankton species were adversely affected at 300 μg Zn/L. Thus, although the HC5 estimated from the bioavailability-normalized SSD was overall protective for the plankton community, the SSD was not able to correctly predict the species sensitivity ranking within their community context at the HC50. Environ Toxicol Chem 2016;35:2698-2712. © 2016 SETAC.
authors.affiliation: Laboratory of Environmental Toxicology and Aquatic Ecology, Environmental Toxicology Unit (GhEnToxLab), Ghent University, Gent, Belgium. Dimitri.VandePerre@Ugent.be.
authors.forename: Dimitri
authors.initials: D
authors.lastname: Van de Perre
authors.affiliation: Alterra, Wageningen University and Research Centre, Wageningen, The Netherlands.
authors.forename: Ivo
authors.initials: I
authors.lastname: Roessink
authors.affiliation: Laboratory of Environmental Toxicology and Aquatic Ecology, Environmental Toxicology Unit (GhEnToxLab), Ghent University, Gent, Belgium.
authors.forename: Colin R
authors.initials: CR
authors.lastname: Janssen
authors.affiliation: Division of Soil and Water Management, Katholieke Universiteit Leuven, Heverlee, Belgium.
authors.forename: Erik
authors.initials: E
authors.lastname: Smolders
authors.affiliation: Laboratory of Environmental Toxicology and Aquatic Ecology, Environmental Toxicology Unit (GhEnToxLab), Ghent University, Gent, Belgium.
authors.forename: Tina
authors.initials: T
authors.lastname: Van Regenmortel
authors.affiliation: Laboratory of Protistology and Aquatic Ecology, Ghent University, Ghent, Belgium.
authors.forename: Jeroen
authors.initials: J
authors.lastname: Van Wichelen
authors.affiliation: Laboratory of Protistology and Aquatic Ecology, Ghent University, Ghent, Belgium.
authors.forename: Wim
authors.initials: W
authors.lastname: Vyverman
authors.affiliation: Alterra, Wageningen University and Research Centre, Wageningen, The Netherlands.|Aquatic Ecology and Water Quality Management Group, Wageningen University and Research Centre, Wageningen University, Wageningen, The Netherlands.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Van den Brink
authors.affiliation: Laboratory of Environmental Toxicology and Aquatic Ecology, Environmental Toxicology Unit (GhEnToxLab), Ghent University, Gent, Belgium.
authors.forename: Karel A C
authors.initials: KA
authors.lastname: De Schamphelaere
mesh_terms: D000818:Animals; D005618:Fresh Water / Q000737:chemistry*; D010839:Phytoplankton / Q000187:drug effects / Q000254:growth & development; D010933:Plankton / Q000187:drug effects* / Q000254:growth & development; D018570:Risk Assessment; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000633:toxicity*; D015032:Zinc / Q000737:chemistry / Q000633:toxicity*; D015048:Zooplankton / Q000187:drug effects / Q000254:growth & development
chemical_list: D014874:Water Pollutants, Chemical; D015032:Zinc
keywords: Biotic ligand model; Community-level effect; Microcosm; Plankton; Zinc