title: Oil droplets do not affect assimilation and survival probability of first feeding larvae of North-East Arctic cod.
abstract: Oil exploration and production in the Atlantic moves northwards towards spawning and nursery areas of fish species that sustain some of the world's largest fisheries. Models are therefore needed that can simulate the effects of accidental oil spills on early life stages of these fish. In this study, we combined an individual based model and a microcosm approach to infer effects of the water soluble fraction (WSF) and of an oil dispersion (WSF and droplets) on two key endpoints of North East Arctic cod (Gadus morhua) larvae: food assimilation rate and survival probability. Both exposure types (WSF and dispersion) decreased assimilation rate (control: 0.4 d(-1)) and survival probability (control: 0.96) in a concentration-dependent fashion, with EC(50)s of about 2 (feeding) and 40 μg/L ∑PAH in the WSF (survival probability). No consistent differences were found between the ECs from the two exposure types indicating no additional oil droplet effects in the oil dispersion. During post exposure, effects on the two endpoints disappeared, which was confirmed by an image analyses we performed of gut content fluorescence. Our results also show that the larvae model fitted the experimental data from the two exposure types equally well, indicating that the presence of oil droplets did not affect model performance. More complex models that explicitly consider possible mechanisms of oil droplet toxicity - in addition to the toxicity of the WSF - on the two examined endpoints during a 17 day time frame do therefore not have a higher accuracy than simpler models that neglect oil droplet toxicity.
authors: SINTEF Materials and Chemistry, Marine Environmental Technology, Brattørkaia 17B, 7010 Trondheim, Norway. Trond.Nordtug@sintef.no
authors: Trond
authors: T
authors: Nordtug
authors: Anders Johny
authors: AJ
authors: Olsen
authors: Dag
authors: D
authors: Altin
authors: Ingrid
authors: I
authors: Overrein
authors: Werner
authors: W
authors: Storøy
authors: Bjørn Henrik
authors: BH
authors: Hansen
authors: Frederik
authors: F
authors: De Laender
mesh_terms: D000818:Animals; D004784:Environmental Monitoring / Q000379:methods*; D005247:Feeding Behavior; D048389:Gadus morhua / Q000254:growth & development / Q000502:physiology*; D008401:Gas Chromatography-Mass Spectrometry / Q000662:veterinary; D005766:Gastrointestinal Contents / Q000187:drug effects*; D007814:Larva / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D008856:Microscopy, Fluorescence / Q000662:veterinary; D008954:Models, Biological; D010578:Petroleum / Q000378:metabolism / Q000633:toxicity*; D059392:Petroleum Pollution / Q000009:adverse effects; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*
chemical_list: D010578:Petroleum; D014874:Water Pollutants, Chemical