Forecast of oil slick drift from Ulysse/ CSL Virginia and Grande America accidents

Abstract

Abstract number 1141410 Two recent accidents with a significant oil spill occurred near the French coast. One in the Mediterranean Sea and the other in the Bay of Biscay. On October 7, 2018, the Tunisian ro-ro vessel Ulysses collided with the Cypriot container ship CSL Virginia at anchor off northern Corsica. The spilled bunker oil could not be fully recovered by the French and Italian anti-pollution vessels due to unfavourable weather conditions. Pellets and highly viscous patties arrived on the beaches of the French Riviera on October 16, 2018. The beaching dates and locations of the main slicks were perfectly predicted using the MOTHY drift model combined with the currents of the CMEMS MED-Currents system. On March 12, 2019, the merchant ship Grande America sank at a depth of 4600 m, 350 km off the French coast, in the Bay of Biscay. It caused a spill of bunker oil and loss of containers. The MOTHY drift model is used daily during the aerial surveillance and recovery at sea period. It provides drift forecasts for oil slicks and containers up to 3 days in deterministic mode and up to 10 days in probabilistic mode. Long-term modelling of residual diffused pollution is also carried out, in particular to manage continuous leakage from the wreck. A technical committee of experts meets daily to evaluate drift observations and forecasts. It focuses on the best choices of available ocean models. Drift forecasts did not indicate any oil arrival to the coast. This allowed the authorities to organise the response at sea without mobilising resources ashore. Indeed, no pollution was observed on the coasts.