The good thing these days is that the effort is made to clean up the spills.
Growing up in Bermuda during the later 50s & 60s tar on the shore & beaches was everywhere. Where did it come from? During WW2 hundreds of ships were sunk in the Atlantic. No effort was made to clean up the spilled bunker oil. Nothing could be done about leaking ships sunk in the deep ocean. Cleanup is a very low priority during a time of war.
Over 70 years later nature has all but finished the cleanup job. Very few small areas of tar covered rocks can be found.