and another one recently - https://en.wikipedia.org/wiki/Refugio_oil_spill
A fair bit of that tar wound up there because of human activity.
100 to 150 barrels worth of liquid petroleum per day. 36,500 to 54,750 per year. It leaks about as much as the 1969 oil spill every 2 years. Or about as much as the Refugio oil spill every month.
I would assume the sudden influx of oil has a hugely adverse affect on wildlife, which still makes them problematic. And 2 years worth of leaks in 10 days sounds catastrophic to the local wildlife. But long term it doesn't seem like either of these spills would be a major contributor to the tar you find on beaches in the region today.
Also, if you need to get tar off your feet after a walk on the beach, baby oil works well :)
An oil company even has a cap over one of the bigger natural leaks to capture the oil that would otherwise be entering the ocean.