title: Influence of a dispersant on the bioaccumulation of phenanthrene by topsmelt (Atherinops affinis).
abstract: Chemical dispersants enhance oil spill dispersion by forming water-accommodated micelles with oil droplets. However, how dispersants alter bioavailability and subsequent bioaccumulation of hydrocarbons is not well understood. Thus, the goal was to investigate the influence of a chemical dispersant on the disposition (uptake, biotransformation, and depuration) of a model hydrocarbon, [14C]-phenanthrene ([14C]PHN), by larval topsmelt (Atherinops affinis). Exposure was via aqueous-only or combined dietary and aqueous routes from a water-accommodated fraction (WAF) of Prudhoe Bay Crude Oil (PBCO) or a WAF of Corexit 9527-dispersed PBCO (DO). Trophic transfer was measured by incorporating into exposure media both a rotifer (Brachionus plicatilis) as food for the fish and a phytoplankton (Isochrysis galbana) as food for the rotifers. Short-term (4 h) bioconcentration of PHN was significantly decreased in topsmelt when oil was treated with dispersant (P < 0.05), but differences diminished after 12 h. When trophic transfer was incorporated, PHN accumulation was initially delayed but after 12 h attained similar levels. Dispersant use also significantly decreased the proportion of biotransformed PHN (as 9-phenanthrylsulfate) produced by topsmelt (P < 0.05). However, overall PHN depuration was not affected by dispersant use. Thus, chemical dispersant use in oil spill response may reduce short-term uptake but not long-term accumulation of hydrocarbons such as PHN in pelagic fish.
authors.affiliation: Department of Ocean Sciences, University of California, Santa Cruz, CA 95064, USA.
authors.forename: E E
authors.initials: EE
authors.lastname: Mielbrecht
authors.forename: M F
authors.initials: MF
authors.lastname: Wolfe
authors.forename: R S
authors.initials: RS
authors.lastname: Tjeerdema
authors.forename: M L
authors.initials: ML
authors.lastname: Sowby
mesh_terms: D000465:Algorithms; D000818:Animals; D001711:Biotransformation; D003362:Cost-Benefit Analysis; D004032:Diet; D056890:Eukaryota / Q000378:metabolism; D020387:Food Chain; D006841:Hydrocarbons, Aromatic / Q000378:metabolism; D007814:Larva / Q000378:metabolism; D036441:Osmeriformes / Q000378:metabolism*; D010578:Petroleum; D010616:Phenanthrenes / Q000378:metabolism* / Q000493:pharmacokinetics; D012403:Rotifera / Q000378:metabolism; D017751:Safety Management / Q000191:economics; D012623:Seawater / Q000032:analysis; D013501:Surface-Active Agents / Q000191:economics / Q000494:pharmacology*
chemical_list: D006841:Hydrocarbons, Aromatic; D010578:Petroleum; D010616:Phenanthrenes; D013501:Surface-Active Agents