Ocean Pollution Bulletin on the Wakashio oil spill accident - Mauritius (24 Aug 2020)


DISCLAIMER - The information and views set out in this Bulletin are those of the authors (CMCC Foundation and cmcc srl) and do not necessarily reflect the official opinion of the governments of the area. CMCC Foundation and cmcc srl do not guarantee the accuracy of the data included in this study. Neither the CMCC Foundation, cmcc srl nor any person acting on the author's behalf may be held responsible for the use which may be made of the information contained therein.

Contact point: Giovanni Coppini; email; phone: +39 3923857919


MEDSLIK-II model, forced with ECMWF and CMEMS products, was used to reproduce the Wakashio spill event and predict its development in the coming hours (30/08/2020 12:00 UTC).

Spill evolution forecast to the 30th of August 2020

Field information, combined with satellite observations, indicate that the Wakashio spill came to a halt on the 16/08. The following spill evolution forecast assumes that further leakages did not take place at the wreck. The analysis is therefore focused on potential oil detachments from impacted areas and movements within and outside the reef.

For the next 24h (24/08 12:00 to 25/08 12:00), dominant meteo-oceanographic conditions will transport part of the oil beached at the northern portion of the reef entrance towards Vieux Grand Port East.

Between the 25/08 12:00 and the 27/08 12:00, part of the beached oil found at the northern portion of the reef entrance could detach and travel south towards Mahebourg. Oil found at the southern part of Ile aux Aigrettes could be transported to Ponte D’Esny. Part of the oil beached at the reef, in the surroundings of the Wakashio wreck, is expected to detach and travel SW following the SE Mauritius coastline. Similar pattern is observed in the following 24h (27th 12:00 to 28th 12:00) with more oil detaching from Ile aux Aigrettes and moving towards Ponte D’Esny, and more oil detaching from the Wakashio surrounding and flowing SW. However, dominant meteooceanographic conditions also pushed the offshore SW flow of oil closer to the shore impacting the SE Mauritius coastline including the beaches of Bassin Carangue and Le Souffleur, Pont Naturel and the Saint Armand river mouth. Similar pattern is observed between the 28th 12:00 and 29th 12:00 and oil beaching is observed at the Le Bouchon and Seneville areas.

Beached oil release from the reef surrounding the Wakashio wreck is expected to persist until the 30th 12:00 moving SW and away from the shore. Part of the beached oil found along the open Mauritius SE coast is expected to return to the sea and travel southwards.

Uncertainties in the present report are expected as deployed booms are not taken into consideration and meteo-oceanographic models might not be capable to fully resolve the coastal dynamics.