title: The impact of sediment bioturbation by secondary organisms on metal bioavailability, bioaccumulation and toxicity to target organisms in benthic bioassays: Implications for sediment quality assessment.
abstract: Bioturbation alters the properties of sediments and modifies contaminant bioavailability to benthic organisms. These naturally occurring disturbances are seldom considered during the assessment of sediment quality. We investigated how the presence (High bioturbation) and absence (Low bioturbation) of a strongly bioturbating amphipod within three different sediments influenced metal bioavailability, survival and bioaccumulation of metals to the bivalve Tellina deltoidalis. The concentrations of dissolved copper decreased and manganese increased with increased bioturbation. For copper a strong correlation was observed between increased bivalve survival (53-100%) and dissolved concentrations in the overlying water. Increased bioturbation intensity resulted in greater tissue concentrations for chromium and zinc in some test sediments. Overall, the results highlight the strong influence that the natural bioturbation activities from one organism may have on the risk contaminants pose to other organisms within the local environment. The characterisation of field-based exposure conditions concerning the biotic or abiotic resuspension of sediments and the rate of attenuation of released contaminants through dilution or readsorption may enable laboratory-based bioassay designs to be adapted to better match those of the assessed environment.
authors.affiliation: School of Chemistry, University of Wollongong, NSW 2522, Australia; Centre for Environmental Contaminants Research, CSIRO Land and Water, Lucas Heights, NSW 2234, Australia.
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Remaili
authors.affiliation: Centre for Environmental Contaminants Research, CSIRO Land and Water, Lucas Heights, NSW 2234, Australia. Electronic address: Stuart.simpson@csiro.au.
authors.forename: Stuart L
authors.initials: SL
authors.lastname: Simpson
authors.affiliation: School of Chemistry, University of Wollongong, NSW 2522, Australia; Centre for Environmental Contaminants Research, CSIRO Land and Water, Lucas Heights, NSW 2234, Australia.
authors.forename: Elvio D
authors.initials: ED
authors.lastname: Amato
authors.affiliation: Centre for Environmental Contaminants Research, CSIRO Land and Water, Lucas Heights, NSW 2234, Australia.
authors.forename: David A
authors.initials: DA
authors.lastname: Spadaro
authors.affiliation: Centre for Environmental Contaminants Research, CSIRO Land and Water, Lucas Heights, NSW 2234, Australia.
authors.forename: Chad V
authors.initials: CV
authors.lastname: Jarolimek
authors.affiliation: School of Chemistry, University of Wollongong, NSW 2522, Australia. Electronic address: djolley@uow.edu.au.
authors.forename: Dianne F
authors.initials: DF
authors.lastname: Jolley
mesh_terms: D033304:Amphipoda; D000818:Animals; D059001:Aquatic Organisms / Q000502:physiology; D001681:Biological Assay; D049872:Bivalvia; D003300:Copper / Q000633:toxicity; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry; D008670:Metals / Q000032:analysis* / Q000633:toxicity; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000633:toxicity; D015032:Zinc / Q000633:toxicity
chemical_list: D008670:Metals; D014874:Water Pollutants, Chemical; D003300:Copper; D015032:Zinc
keywords: Benthic invertebrates; Bioassays; Contaminants; Sediment quality guidelines; Speciation