Following an oil spill, a variety of tools are available to mitigate the damage to aquatic ecosystems. In remote high-latitude regions, chemical herders may be applied to contract and thicken spilled crude oil prior to in-situ burning (ISB). Little information exists on the water-soluble residues stemming from this process, how these residues weather, and how marine biota may be affected by exposure. In this study, controlled bench-scale burns were performed over herded and non-herded ANS crude oil, transferred to aquaria with seawater, and allowed to incubate over 28 days at 4 deg C. Petroleum-derived dissolved organic matter (DOMHC) was characterized using optical (fluorescence EEMs) and Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS). The seawater microbial community was assessed using 16S rRNA next-generation sequencing. ISB, both with and without the addition of herder, had a significant impact on both the DOMHC chemical composition and 16s rRNA seawater microbial community diversity, compared to non-combusted oiled seawater. Oil+ISB selected for Marinomonas and Perlucidibaca, which are known hydrocarbon degraders, and the abundance of these genera were driven primarily by relative aromatic percentage in DOMHC. Herder application and ISB induces a unique molecular signature that is represented in FT-ICR MS and optical measurements. We postulate the composition of DOMHC contains oxidized non-aromatics and/or CRAM (carboxyl rich alicyclic molecules) formed either by combustion and/or physical partitioning associated with enhanced solubility of these fractions.

Herded burned crude oil at high latitudes: Water soluble fraction, weathering, and effects on seawater microbial community diversity

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.