title: Beyond the bed: effects of metal contamination on recruitment to bedded sediments and overlying substrata.
abstract: Metal-contaminated sediments pose a recognised threat to sediment-dwelling fauna. Re-mobilisation of contaminated sediments however, may impact more broadly on benthic ecosystems, including on diverse assemblages living on hard substrata patches immediately above sediments. We used manipulative field experiments to simultaneously test for the effects of metal contamination on recruitment to marine sediments and overlying hard substrata. Recruitment to sediments was strongly and negatively affected by metal contamination. However, while assemblage-level effects on hard-substratum fauna and flora were observed, most functional groups were unaffected or slightly enhanced by exposure to contaminated sediments. Diversity of hard-substratum fauna was also enhanced by metal contamination at one site. Metal-contaminated sediments appear to pose less of a hazard to hard-substratum than sediment-dwelling assemblages, perhaps due to a lower direct contaminant exposure or to indirect effects mediated by contaminant impacts on sediment fauna. Our results indicate that current sediment quality guidelines are protective of hard-substrata organisms.
authors.affiliation: Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Kensington, New South Wales 2052, Australia. Nicole.Hill@utas.edu.au
authors.forename: Nicole A
authors.initials: NA
authors.lastname: Hill
authors.forename: Stuart L
authors.initials: SL
authors.lastname: Simpson
authors.forename: Emma L
authors.initials: EL
authors.lastname: Johnston
mesh_terms: D000818:Animals; D059001:Aquatic Organisms; D044822:Biodiversity; D017753:Ecosystem; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry*; D007448:Invertebrates / Q000145:classification / Q000254:growth & development; D008670:Metals / Q000032:analysis* / Q000633:toxicity; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000633:toxicity
chemical_list: D008670:Metals; D014874:Water Pollutants, Chemical