Impact of oil spills

Oil spills impact on the surrounding environment, natural populations and economic activities. The quantity of pollutant spilled largely determines these impacts. However the nature of the pollutant, the location and the context also play a major role.

The lighter the product, the more easily it evaporates in the atmosphere, thus reducing the quantity of pollutant remaining in the marine environment. Certain crude oils, such as North Sea oil, are so volatile that the volume spilled can reduce by more than 40% through evaporation alone. At the opposite end of the spectrum, the heavy fuel oils from the Erika and the Prestige did not reduce in volume by even 10% through evaporation.

Impact on the fauna

In the event of a fire, the quantity of spilled oil that will affect the environment can be considerably reduced. However, fire can cause other dangers and air pollution.

The extent and form of the pollution which reaches the shore is influenced by the distance separating the spill location and the coast, the shore morphology and permanent and seasonal winds and currents. The nature of the shore renders it more or less sensitive.

Subsequent arrivals of oil in a previously affected area after a break of several months or years can exacerbate the imbalance in recovering populations and economic activities, with the risk of pushing them into an irremediable situation.

Each case is therefore unique and it is easy to think of the particular oil spill with which we are familiar as far worse than that experienced by others.

Impact on the shore

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Distribution in the air and the water of tonnage of oil spilled

Source: Cedre estimations