The Agia Zoni II oil spill: Short-term fate and imprint on the marine ecosystem of the Saronikos Gulf, Greece

Herein we examine the spatial and temporal imprint of the September 2017 Agia Zoni II tanker heavy fuel oil spill on the marine ecosystem of the Saronikos Gulf, Greece. Based on the chemical fingerprinting approach, by means of gas chromatography - flame ionization detector and gas chromatography–mass spectrometry and the use of various diagnostic ratios, we characterize changes in the composition of the spilled oil across sampling sites and evaluate major mechanisms affecting its fate i.e. dissolution/dispersion, evaporation, biodegradation, photo-oxidation and sediment accumulation during the first six months from the spill. Overall, the main effects of the incident were confined to the coastal zone during the first three months after the spill, where an extended petroleum imprint was recorded in many cases with determined total petroleum hydrocarbons and polycyclic aromatic hydrocarbons concentrations falling within the highest range of concentrations previously reported in similar oil spill incidents worldwide. In the first three months following the spill the oil was affected by a combination of rapid biodegradation, volatilization processes and photodegradation, the later playing a role in its early days weathering. Regarding sediments, an imprint related to the incident was recorded in some cases but mild in respect to the high chronic petroleum-associated anthropogenic background of the affected area.