Invertebrate communities in soft sediments along a pollution gradient in a Mediterranean river (Llobregat, NE Spain) - López-Doval, Julio César (Universitat de Barcelona. Departament d'Ecologia) ; Grossschartner, Monika (Consulting Engineers of Hydro-Ecology and Landscaping. Dws Hydro-Ökologie GmbH) ; Höss, Sebastian (Giselastr. Ecossa) ; Orendt, Claus (Brandvorwerkstr. WaterBioAssessment) ; Traunspurger, Walte (University of Bielefeld. Department of Animal Ecology) ; Wolfram, Georg (Consulting Engineers of Hydro-Ecology and Landscaping. Dws Hydro-Ökologie GmbH) ; Muñoz, I. (Universitat de Barcelona. Departament d'Ecologia)