In situ biodegradation, photooxidation and dissolution of petroleum compounds in Arctic seawater and sea ice

WATER RESEARCH

卷:148

Article

Vergeynst, Leendert^1,2,3  Christensen, Jan H.⁴  Kjeldsen, Kasper Urup^2,3  Meire, Lorenz^5,6  Boone, Wieter⁷  Malmquist, Linus M. V.⁴  Rysgaard, Soren^1,7 

[1] Aarhus Univ, Arctic Res Ctr, Aarhus, Denmark

[2] Aarhus Univ, Sect Microbiol, Aarhus, Denmark

[3] Aarhus Univ, Dept Biosci, Ctr Geomicrobiol, Aarhus, Denmark

[4] Univ Copenhagen, Fac Sci, Dept Plant & Environm Sci, Copenhagen, Denmark

[5] Greenland Inst Nat Resources, Greenland Climate Res Ctr, Nuuk, Greenland

[6] Univ Utrecht, Royal Netherlands Inst Sea Res, Dept Estuarine & Delta Syst, Yerseke, Netherlands

[7] Univ Manitoba, Ctr Earth Observat Sci, Winnipeg, MB, Canada

关键词: Oil spill;    Biodegradation;    Bacterial community;    Photooxidation;    Arctic;    Sea ice;   

DOI  :  10.1016/j.watres.2018.10.066

来源: Elsevier

【 摘 要 】

In pristine sea ice-covered Arctic waters the potential of natural attenuation of oil spills has yet to be uncovered, but increasing shipping and oil exploitation may bring along unprecedented risks of oil spills. We deployed adsorbents coated with thin oil films for up to 2.5 month in ice-covered seawater and sea ice in Godthaab Fjord, SW Greenland, to simulate and investigate in situ biodegradation and photooxidation of dispersed oil. GC-MS-based chemometric methods for oil fingerprinting were used to identify characteristic signatures for dissolution, biodegradation and photooxidation. In sub-zero temperature seawater, fast degradation of n-alkanes was observed with estimated half-life times of similar to 7 days. PCR amplicon sequencing and qPCR quantification of bacterial genes showed that a biofilm with a diverse microbial community colonised the oil films, yet a population related to the psychrophilic hydrocarbonoclastic gammaproteobacterium Oleispira antarctica seemed to play a key role in n-alkane degradation. Although Oleispira populations were also present in sea ice, we found that biofilms in sea ice had 25 to 100 times lower bacterial densities than in seawater, which explained the non-detectable n-alkane degradation in sea ice. Fingerprinting revealed that photooxidation, but not biodegradation, transformed polycyclic aromatic compounds through 50 cm-thick sea ice and in the upper water column with removal rates up to similar to 1% per day. Overall, our results showed a fast biodegradation of n-alkanes in sea ice-covered seawater, but suggested that oils spills will expose the Arctic ecosystem to bio-recalcitrant PACs over prolonged periods of time. (C) 2018 Elsevier Ltd. All rights reserved.

【 授权许可】

Free