Response at sea
Since the heavy fuel from the Erika was not dispersible, the only response option at sea was containment and recovery.
Attempts to agglomerate the pollutant to make it thicker to facilitate 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 decision 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 involving the tanker Sea Empress in Wales, in 1996, had already shown that European mutual assistance agreements could ensure a joint response in the event of a major spill. The French Navy engaged response at sea with the two ships available, the Alcyon and Ailette, plus the Dutch vessel Arca, the German Neuwerk, the 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 abandoning recovery attempts with the Transrec, opting instead for a Foilex skimmer, a smaller capacity recovery device. Harsh sea conditions forced teams to postpone the response attempts, after damage to equipment on 18 December. An asphalt tanker, provided by TotalFina to receive the pumped oil joined the response fleet. On 20 December, 60 m³ of oil was recovered, confirming the technical feasibility of the operation. By 21 December, the volume recovered at sea had 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 (8 m³ of pollutant recovered). In total, in harsh sea conditions, 1,200 tonnes of fuel oil was recovered, sparing thousands of sea birds, reducing pollution on the coast, and avoiding the cost of the recovery and disposal of an estimated 11,000 to 12,000 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, equipped with gear to trawl the water column from the surface to the bottom to attempt to detect subsurface slicks.
None of the techniques deployed resulted in the detection of oil in the water column.