Comparative toxicity assessment of in situ burn residues to initial and dispersed heavy fuel oil using zebrafish embryos as test organisms

Abstract

In situ burning (ISB) is discussed to be one of the most suitable response strategies to combat oil spills in extreme conditions. After burning, a highly viscous and sticky residue is left and may over time pose a risk of exposing aquatic biota to toxic oil compounds. Scientific information about the impact of burn residues on the environment is scarce. In this context, a comprehensive ISB field experiment with approx. 1000L IFO 180 was conducted in a fjord in Greenland. The present study investigated the toxicity of collected ISB residues to early life stages of zebrafish (Danio rerio) as a model for potentially exposed pelagic organisms. The toxicity of ISB residues on zebrafish embryos was compared with the toxicity of the initial (unweathered) IFO 180 and chemically dispersed IFO 180. Morphological malformations, hatching success, swimming behavior, and biomarkers for exposure (CYP1A activity, AChE inhibition) were evaluated in order to cover the toxic response on different biological organization levels. Across all endpoints, ISB residues did not induce greater toxicity in zebrafish embryos compared with the initial oil. The application of a chemical dispersant increased the acute toxicity most likely due to a higher bioavailability of dissolved and particulate oil components. The results provide insight into the adverse effects of ISB residues on sensitive life stages of fish in comparison with chemical dispersant application.

Chemical and toxicological characterisation of residues from offshore in-situ burning of spilled fuel oils

“…The PAH concentrations were 0.185 mg/L in WAF of initial oil, and 0.052 mg/L in WAF of burned oil which for the same 18 PAHs is in the same range as in our study which was 0.165 mg/L and 0.030 mg/l, respectively. In line with our results Johann et al [ 11 ] observed higher acute mortality for the fresh oil WAF than for the burnt residue WAF. However, based on the sublethal effects they concluded that there were no overt differences in the acute toxicity of the WAFs of IFO180 and burned IFO180 to zebrafish embryos.…”

“…In a recent study, Johann et al [ 11 ] prepared LE-WAFs with IFO180 and ISB residue of IFO180 for exposure experiments using zebrafish in a fish acute embryo toxicity test (120 h post fertilization). The WAF concentrations were quantified by 18 unsubstituted PAHs, but neither TPH nor volatiles were analysed.…”

“…There are relative few studies that have investigated the toxicity of ISB residues according to a review by Fritt-Rasmussen et al [ 10 ], and none of them had studied the effects of residues from ISB of fuel oils. However, in a recent paper by Johann et al [ 11 ], the toxicity of ISB residues of IFO180 to early life stages of zebrafish was investigated. They concluded that ISB residues did not induce greater toxicity in zebrafish embryos compared with the initial oil.…”

Ecotoxicological evaluation of surface waters in Northern Namibia

“…The fish embryo acute toxicity test was applied as a limit test with fertilized eggs of the zebrafish ( Danio rerio) , based on the DIN guideline and the OECD guideline 236 (DIN EN ISO, 2008 ; OECD, 2013a ; Shuliakevich et al, 2022b ). As described in Johann et al ( 2021 ), the experiments were terminated shortly before 120-h post-fertilization (hpf). According to the Directive 2010/63/EU (European Union, 2010 ), testing zebrafish embryos and larvae before 120 hpf does not require animal ethics test approval.…”

Bio‐based polydimethylsiloxane porous sponge materials with programmable hydrophobicity and porosity for efficient separation of hydrophobic liquids from water

“…The species in local vicinity face the death fate with in short duration of the spill accidents 17–19 . Deformities in the embryo of many species of fish 20 and shift in the community composition of species 13 are the reported long term effects 21 . Some of the cleanup methods also pollute the local environment 22 and put serious risk on the survival of the surrounding species 23 …”