The greatest sea disaster ever happened in 1978 when the tanker named Amoco-Cadiz contaminated with 280,000 tonnes of crude oil the coasts off Bretagne (Western France).
Maybe better known is the ecological catastrophe that Exon Valdez produced in 1989 on Alaska's shores.
During the 1991 Gulf War, roughly one million oil tonnes blackened the Persian Gulf.
In 1992, The "Aegean See" got stuck in La Coruna (Northwestern Spain) and to the escape of 80,000 tonnes of oil, a giant cloud provoked by the partial combustion of the oil was added.
Fresher in our memory are two events: The 1999 "Erika" accident, off Bretagne coasts, when, beside the 12,000 tonnes of escape, other 18,000 tonnes of crude oil stored in the reservoirs had to be pumped out.
the infamous "Prestige" incident, in November 2002, off Galicia (Northwestern Spanish coasts), which poured 64,000 tonnes of contaminant material, reaching even the French coasts and being the greatest environmental catastrophe in Spain's history.
Which are the environmental and economic consequences of an oil spill? Hundreds of species of marine mammals (cetaceans, seals, otters), marine birds, marine turtles, fish, crustaceans, and mollusks lose their habitat. Most animals die smeared by the oil or poisoned by the toxic compounds (including carcinogen) of the hydrocarbons. Bottom animals, like mussels, which feed by filtering the water, ingest very quickly the toxins and die.
Fishing and seafood harvesting are banned. Marine flora stops the photosynthesis, by not receiving light, and the oxygen vanishes. After such a disaster, the ecosystems need 6 to 10 years to recover.
So, how do we operate in case of an oil spill? The most important thing is to stop the oil from spreading. To this end floating barriers are used, but they are effective only when the sea is calm. In the areas where crude oil accumulates, it can be sucked out by pumps. If it's very thick, some chemical compounds are added to turn it more fluid.
Oil absorbing skimmers can be used; they cleanse the crude oil while marching through it. When the oil reaches the coast, the only option is to remove the sand or soil impregnated with oil. Sometimes heavy machinery is used.
The workers must operate protected by plastic overall to avoid direct contact with the oil. They use pressured water jets and biodegradable detergents to cleanse small areas. Recovered birds that have the plumage oiled are wrapped in cloths to avoid hypothermy. In the "Erika" event 100,000 birds died.
Marine mammal fur also loses its insulator feature and the mammals must be washed with serum outside and inside, in case of oil ingestion. Currently, satellites are used to track down tankers that escape oil. The specialists analyze the oil samples, check the tankers that passed the area, and the registers link the crude oil type to a specific refinery where the boat was filled.