Evaporation

This is from an article I found today.. "Gasoline is more toxic to wildlife than other types of oil, Knox said. The only positive is that being lighter, it evaporates quickly and breaks up. Crude oil is more persistent and difficult to cleanse from the environment"

Read more: http://www.timescolonist.com/news/Gasoline+spill+likely+killed+thousands+Goldstream+River+salmon/4631777/story.html#ixzz1Ls9CBW8O

I think it would be interesting to find the evaporation rate of the oil, and thus estimate how long it will take to be completely evaporated from the water.
I'm sure I can do something like this in the lab.