title: Review on the effects of toxicants on freshwater ecosystem functions.
abstract: We reviewed 122 peer-reviewed studies on the effects of organic toxicants and heavy metals on three fundamental ecosystem functions in freshwater ecosystems, i.e. leaf litter breakdown, primary production and community respiration. From each study meeting the inclusion criteria, the concentration resulting in a reduction of at least 20% in an ecosystem function was standardized based on median effect concentrations of standard test organisms (i.e. algae and daphnids). For pesticides, more than one third of observations indicated reductions in ecosystem functions at concentrations that are assumed being protective in regulation. Moreover, the reduction in leaf litter breakdown was more pronounced in the presence of invertebrate decomposers compared to studies where only microorganisms were involved in this function. High variability within and between studies hampered the derivation of a concentration-effect relationship. Hence, if ecosystem functions are to be included as protection goal in chemical risk assessment standardized methods are required.
authors.affiliation: Quantitative Landscape Ecology, Institute for Environmental Science, University of Koblenz-Landau, Fortstraße 7, D-76829 Landau, Germany. peters@uni-landau.de
authors.forename: K
authors.initials: K
authors.lastname: Peters
authors.forename: M
authors.initials: M
authors.lastname: Bundschuh
authors.forename: R B
authors.initials: RB
authors.lastname: Schäfer
mesh_terms: D000818:Animals; D017753:Ecosystem; D004784:Environmental Monitoring; D005618:Fresh Water / Q000737:chemistry*; D007448:Invertebrates; D010575:Pesticides / Q000633:toxicity; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D014877:Water Pollution, Chemical / Q000706:statistics & numerical data
chemical_list: D010575:Pesticides; D014874:Water Pollutants, Chemical
keywords: Aquatic; Community respiration; Decomposition; Primary production; Toxic units