Three years after bulk carrier ran aground on a coral reef off Mauritius, spilling 1000 tonnes of a new type of marine fuel oil, 麻豆直播-led research has confirmed the oil is still present in an environmentally sensitive mangrove forest close to important conservation sites.
Lead researcher , from Curtin鈥檚 WA Organic and Isotope Geochemistry Centre in the School of Earth and Planetary Sciences, said the chemical 鈥榝ingerprint鈥� of the oil found in the mangrove sediments was a near-perfect match for the Very Low Sulphur Fuel Oil (VLSFO) spilled by the Wakashio in 2020 – the first recorded spill involving this type of fuel.
鈥淟ocal communities in Mauritius have been aware of oil contamination in the mangrove wetlands since the Wakashio spill, but no official confirmation had been made regarding the source,鈥� Dr Scarlett said.
鈥淚dentifying and acknowledging this contamination is crucial, both for the people of Mauritius and for global understanding, as little is known about how this new marine fuel behaves once spilled.鈥�
Dr Scarlett said samples from the mangrove wetlands, including a reference site thought to be unaffected by the spill, were analysed using advanced chemical techniques.
鈥淲e confirmed the reference site was free of oil contamination, while another site contained oil originating from the Wakashio鈥檚 fuel tanks,鈥� Dr Scarlett said.
鈥淲e found the spilled oil had undergone substantial weathering and biodegradation in the three years since the accident and this had removed or reduced the levels of many of its toxic compounds.
鈥淗owever, the ongoing presence of the oil could still pose an unknown risk to the sensitive mangrove ecosystem.鈥�
In a previous collaboration with the Woods Hole Oceanographic Institution, the Curtin research team obtained a unique chemical 鈥榝ingerprint鈥� of the spilled oil, which enabled them to confirm its presence in the mangrove sediments.
The study also compared the behaviour of the Wakashio‘s VLSFO with traditional marine heavy fuel oils using models developed from the National Oceanic and Atmospheric Administration鈥檚 oil spill scenario tool, .
鈥淥ur modelling suggested more of the Wakashio鈥檚 fuel would evaporate, naturally disperse or sink compared to traditional fuels, but assessing the impact on organisms remains challenging,鈥� Dr Scarlett said.
The research, titled 鈥�Very Low Sulfur Fuel Oil spilled from the MV Wakashio in 2020 remains in sediments in a Mauritius mangrove ecosystem nearly three years after the grounding鈥�, was published in .
