title: Development of a larval bioassay using the calanoid copepod, Eurytemora affinis to assess the toxicity of sediment-bound pollutants.
abstract: Hydrophobic pollutants, in particular sediment-sorbed organic compounds, are widespread in the aquatic environment and could represent a threat to living organisms. Estuarine species, which live in turbulent ecosystems, are particularly exposed to this mode of contamination. For precise evaluation of the toxicity of hydrophobic contaminants desorbed from particles, a new larval assay using nauplii of the estuarine calanoid copepod Eurytemora affinis was developed. It consists of the direct exposure of copepods during naupliar development to elutriates of an unpolluted sediment spiked with different model contaminants. This bioassay measures the toxicity of the bioavailable fraction of particle-sorbed pollutants on the naupliar stage of copepods. Mortality and growth (non-invasive endpoints) in nauplii were analysed after six days of exposure. This approach was validated using six pollutants with different modes of action: benzo[a]pyrene (BaP), dimethylbenzo[a]anthracene (DMBA), phenanthrene (PHE), polychlorinated biphenyls (PCB 126, PCB 153) and 4-nonylphenol (4-NP). All these compounds induced a dose-dependent increase in toxic effects. Lethal effects only occurred at the highest tested concentrations: 58,541 and 6092 ng g(-1) dry weight sediment (dws), for PHE and DMBA, respectively. Sublethal effects (growth inhibition) were observed at lower concentrations for all tested compounds except PCB 153, from 8, 142, 297, 6092 and 8453 ng g(-1) dws for PCB 126, BaP, PHE, DMBA and 4-NP, respectively.
authors.affiliation: Normandie University, ULH, LEMA EA 3222, F-76600 Le Havre, France.
authors.forename: Teddy
authors.initials: T
authors.lastname: Lesueur
authors.forename: Céline
authors.initials: C
authors.lastname: Boulangé-Lecomte
authors.forename: Benoît
authors.initials: B
authors.lastname: Xuereb
authors.forename: Hélène
authors.initials: H
authors.lastname: Budzinski
authors.forename: Jérôme
authors.initials: J
authors.lastname: Cachot
authors.forename: Ludovic
authors.initials: L
authors.lastname: Vicquelin
authors.forename: Nathalie
authors.initials: N
authors.lastname: Giusti-Petrucciani
authors.forename: Sabine
authors.initials: S
authors.lastname: Marie
authors.forename: Fabienne
authors.initials: F
authors.lastname: Petit
authors.forename: Joëlle
authors.initials: J
authors.lastname: Forget-Leray
mesh_terms: D000818:Animals; D001681:Biological Assay / Q000379:methods*; D033342:Copepoda / Q000187:drug effects / Q000502:physiology*; D004784:Environmental Monitoring / Q000379:methods*; D019015:Geologic Sediments / Q000737:chemistry*; D007814:Larva / Q000187:drug effects; D011078:Polychlorinated Biphenyls / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D014874:Water Pollutants, Chemical; D011078:Polychlorinated Biphenyls