title: Biomass estimation across the benthic community in polluted freshwater sediment--a promising endpoint in microcosm studies?
abstract: With respect to the ecological relevance of endpoints, biomass as an endpoint might be promising regarding ecotoxicological assessments of benthic communities. In a freshwater microcosm study the effect of two cadmium (Cd) concentrations (50 and 400 mg Cd kg(-1) dw) on biomass and abundance of a benthic community were investigated over a period of seven months. Specifically, the sensitivity of both endpoints in distinguishing differential effects was compared. While bacteria were found to be unaffected by Cd, abundance and biomass of protozoans and metazoans decreased. In a short-term comparison, differences between control and Cd treatments were, overall, more pronounced for flagellate biomass and for metazoan abundance with strong differences between the taxonomic groups; furthermore, over the long-term, the differences among organisms and endpoints changed. Based on toxicant sensitivity, the reasonably low variance of the data and the workload involved, biomass can provide a useful additional endpoint in microcosm studies.
authors.affiliation: Department of Animal Ecology, University of Bielefeld, Morgenbreede 45, 33615 Bielefeld, Germany. michael.faupel@uni-bielefeld.de
authors.forename: Michael
authors.initials: M
authors.lastname: Faupel
authors.forename: Kai
authors.initials: K
authors.lastname: Ristau
authors.forename: Walter
authors.initials: W
authors.lastname: Traunspurger
mesh_terms: D000818:Animals; D001419:Bacteria / Q000187:drug effects; D018533:Biomass; D058448:Biota; D002104:Cadmium / Q000633:toxicity*; D016798:Ciliophora / Q000187:drug effects; D054750:Ecotoxicology / Q000379:methods; D004784:Environmental Monitoring / Q000379:methods; D005618:Fresh Water / Q000737:chemistry*; D019015:Geologic Sediments / Q000737:chemistry*; D007448:Invertebrates / Q000187:drug effects; D012680:Sensitivity and Specificity
chemical_list: D002104:Cadmium