Those who disagree with these comments describing the properties of bitumen are disagreeing with scientific facts.  The waters around the Exon Valdez catastrophe of March 1989 have still not seen the return of the herring fishery. Why? The ocean floor still has that oil lying there. Turn over rocks on the shore and you still see that Exxon Valdez oil. That was refined oil....not tarsands  bitumen of which there is no viable system of recovery.