title: Quantification of bioavailable nickel in sediments and toxic thresholds to Hyalella azteca.
abstract: Bioaccumulation and chronic toxicity of nickel (Ni) to Hyalella azteca in Ni-spiked sediments was strongly affected by the source of sediment used. The total range in LC50s on a sediment concentration basis ranged over 20 fold. Differences in Ni toxicity generally matched differences in Ni bioaccumulation, and toxicity expressed on a body concentration basis varied less than three fold. Body concentrations, therefore, provide a much more reliable prediction of Ni toxicity in sediments than do concentrations in the sediment. Ni in overlying water was also a reliable predictor of Ni toxicity, but only in tests conducted in Imhoff settling cones with large (67:1) water to sediment ratios. Overlying water LC50s for tests in beakers varied 18 fold. Sediment and body concentrations of Ni tolerated by Hyalella were slightly higher in cones than in beakers. Reproduction was not affected significantly by Ni at concentrations below the LC50 and 10-week EC50s for survival and biomass production (including survival, growth and reproduction) were only marginally lower than 4-week EC50s (survival and growth only).
authors.affiliation: National Water Research Institute, Environment Canada, 867 Lakeshore Road, PO Box 5050, Burlington, Ontario, Canada L7R 4A6. uwe.borgmann@cciw.ca
authors.forename: U
authors.initials: U
authors.lastname: Borgmann
authors.forename: R
authors.initials: R
authors.lastname: Néron
authors.forename: W P
authors.initials: WP
authors.lastname: Norwood
mesh_terms: D000818:Animals; D001682:Biological Availability; D018533:Biomass; D003445:Crustacea / Q000502:physiology*; D019015:Geologic Sediments / Q000737:chemistry; D007928:Lethal Dose 50; D009532:Nickel / Q000009:adverse effects* / Q000493:pharmacokinetics*; D011157:Population Dynamics; D012098:Reproduction; D016019:Survival Analysis; D014874:Water Pollutants, Chemical / Q000009:adverse effects* / Q000493:pharmacokinetics*
chemical_list: D014874:Water Pollutants, Chemical; D009532:Nickel