Comparison of Very Low Sulphur Fuel Oil With Spilled Oil Following Grounding of Mv Wakashio in Mauritius, 2020

Summary The bulk carrier MV Wakashio ran aground on a coral reef offshore of Pointe d’Esny, Southeast Mauritius releasing an estimated 1000 t of fuel oil into the Indian Ocean threatening internationally important wetlands. It was reported to be carrying approximately 3,800 t of Very Low Sulphur Fuel Oil (VLSFO, defined as <0.5 %). A sample of oil was collected from close to shore and subsequently shipped to laboratories of (WA-OIGC), Perth, Australia and Woods Hole Oceanographic Institution (WHOI), USA for analysis. Together with a sample of Wakashio fuel oil, multi-spectroscopic techniques, including high resolution gas chromatography mass spectrometry, compound specific isotopic analysis and elemental analysis, were used to characterise and compare the oils. Initial results were consistent with the spilled oil being a type of VLSFO. Although somewhat weathered, key biomarker profiles of the spilled oil matched the Wakashio fuel oil. This is to our knowledge the first reported spill of VLSFO.