title: Influence of sample manipulation on contaminant flux and toxicity at the sediment-water interface.
abstract: Toxicities of sediments from San Diego and San Francisco Bays were compared in laboratory experiments using sea urchin (Strongylocentrotus purpuratus) embryos exposed to pore water and at the sediment-water interface (SWI). Toxicity was consistently greater to embryos exposed at the SWI to intact (unhomogenized) sediment samples relative to homogenized samples. Measurement of selected trace metals indicated considerably greater fluxes of copper, zinc, and cadmium into overlying waters of intact sediment samples. Inhibition of sea urchin embryo development was generally greater in sediment pore waters relative to SWI exposures. Pore water toxicity may have been due to elevated unionized ammonia concentrations in some samples. The results indicate that invertebrate embryos are amenable to SWI exposures, a more ecologically relevant exposure system, and that sediment homogenization may create artifacts in laboratory toxicity experiments.
authors.affiliation: Environmental Toxicology Department, University of California, Davis, CA 95616, USA. anderson@ucdavis.edu
authors.forename: B S
authors.initials: BS
authors.lastname: Anderson
authors.forename: J W
authors.initials: JW
authors.lastname: Hunt
authors.forename: B M
authors.initials: BM
authors.lastname: Phillips
authors.forename: R
authors.initials: R
authors.lastname: Fairey
authors.forename: H M
authors.initials: HM
authors.lastname: Puckett
authors.forename: M
authors.initials: M
authors.lastname: Stephenson
authors.forename: K
authors.initials: K
authors.lastname: Taberski
authors.forename: J
authors.initials: J
authors.lastname: Newman
authors.forename: R S
authors.initials: RS
authors.lastname: Tjeerdema
mesh_terms: D000641:Ammonia / Q000009:adverse effects / Q000032:analysis; D000818:Animals; D004625:Embryo, Nonmammalian / Q000187:drug effects; D047108:Embryonic Development; D019015:Geologic Sediments / Q000737:chemistry*; D019216:Metals, Heavy / Q000633:toxicity*; D015203:Reproducibility of Results; D012617:Sea Urchins; D018675:Toxicity Tests
chemical_list: D019216:Metals, Heavy; D000641:Ammonia