title: Bacterial communities are sensitive indicators of contaminant stress.
abstract: With many environments worldwide experiencing at least some degree of anthropogenic modification, there is great urgency to identify sensitive indicators of ecosystem stress. Estuarine organisms are particularly vulnerable to anthropogenic contaminants. This study presents bacterial communities as sensitive indicators of contaminant stress. Sediments were collected from multiple sites within inner and outer zones of three heavily modified and three relatively unmodified estuaries. Bacterial communities were censused using Automated Ribosomal Intergenic Spacer Analysis and analysed for a suite of metal and PAH contaminants. Shifts in both bacterial community composition and diversity showed strong associations with sediment contaminant concentrations, particularly with metals. Importantly, these changes are discernable from environmental variation inherent to highly complex estuarine environments. Moreover, variation in bacterial communities within sites was limited. This allowed for differences between sites, zones and estuaries to be explained by variables of interest such as contaminants that vary between, but not within individual sites.
authors.affiliation: Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia. melanie.sun@student.unsw.edu.au
authors.forename: Melanie Y
authors.initials: MY
authors.lastname: Sun
authors.forename: Katherine A
authors.initials: KA
authors.lastname: Dafforn
authors.forename: Mark V
authors.initials: MV
authors.lastname: Brown
authors.forename: Emma L
authors.initials: EL
authors.lastname: Johnston
mesh_terms: D001419:Bacteria / Q000145:classification / Q000187:drug effects* / Q000254:growth & development; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods*; D008670:Metals / Q000032:analysis / Q000633:toxicity; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis / Q000633:toxicity; D012623:Seawater / Q000737:chemistry; D014871:Water Microbiology; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000633:toxicity*
chemical_list: D008670:Metals; D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical