Since the heavy fuel could not be dispersed, the only response option at sea was containment and recovery. Agglomerating the pollutant to make it more consistent for recovery with surface trawls would have led to complicated technical problems, such as transporting and spreading products, or loading the filled trawls on board recovery vessels. The decisin was therefore made to pump the oil. The operation was difficult because the product was highly viscous and the sea was rough. On the other hand, it was facilitated by the thickness of the slicks.
The incident of the tanker Sea Empress in Wales, in 1996, showed that European agreements of mutual assistance ensured joint response in the event of a major spillage. The French Navy engaged response at sea with the two ships available, the Alcyon and Ailette, plus the Dutch Arca, the German Neuwerk, the British British Shield and two Spanish ships the Ibaizadal II and the Alonso de Chaves. Unfortunately, the Spanish vessels were not yet equipped for oil recovery.
On 15 December, in fairly rough sea conditions, the Ailette unsuccessfully attempted to operate a Transrec recovery device. Further pumping tests, carried out on 16 December, finally resulted in giving up the Transrec for a Foilex heavy oil, a smaller capacity recovery device. It worked, but harsh sea conditions forced teams to postpone the response attempts, after damages to equipment on 18 December, when an asphalt tanker, provided by TotalFina to receive the pumped oil joined the response fleet. On 20 December, 60 m³ of oil were recovered, confirming the technical feasibility of the operation. On 21 December, the volume recovered at sea reached 500 m³. On 22 December, in spite of the difficult weather conditions, the volume recovered neared 1,000 m³. When meteorological conditions forced operations to stop, on 23 December, the quantity of emulsion recovered at sea had reached 1,200 m³. On 30 December, fair weather conditions allowed short pumping operations off the coast of Vendée. They were carried out by the French Navy vessel the Elan, with a Dacama device and a Foilex pump, and by fishing boats using Seynip oil trawls. 8 m³ of pollutant were recovered.
In total, response at sea recovered 1,200 tonnes of fuel, sparing thousands of sea birds, reducing pollution on the coast, and avoiding the onshore efforts and cost of the recovery and disposal of 12,000 to 15,000 tonnes of oiled algae, sand, pebbles and waste.
From 16 February, a program for spotting oil slicks floating beneath the sea surface or lying on the sea bottom was set up in the vicinity of the wrecks and near the coast. Divers carried out underwater inspections along the coast of Loire Atlantique and Morbihan. From 21 February, two vessels belonging to the marine research institute IFREMER searched for sunken oil with dredges along the 10 m depth line. A French Navy survey vessel searched the 50 m depth line. No oil was detected in the water column. Only small, isolated tar balls were found on the sea bottom.
Since the heavy fuel could not be dispersed, the only response option at sea was containment and recovery.