"Oil is not persistent - it's not that toxic, " said Dr Kingston.

BBC: Oil spills: What is the long-term damage?

Mr. SHORT: That was a bit of a surprise too, that the oil could be persistent and still toxic sitting here 17 years later.

NPR: Valdez: The Damage Persists, 17 Years Later

With global demand for oil growing by 1-2% a year, there are persistent fears of a supply shock.

ECONOMIST: Oil firms you have never heard of are booming