I've heard the average daily output from natural seeps in the Coal Oil Point area is about 50,000 gallons. I drove past the spill site yesterday and caught of whiff of tarry Santa Barbara crude. The post-cleanup repairs were in progress. Looks like pretty small potatoes, not a reprise of the Torrey Canyon disaster the Guardian is pitching. You go walking around the beach there and you may step in tar from a natural seep. Despite the closed beaches there were surfers out there north and south.
Updated info. The amount of oil is immense that leaks in just these few places. Imagine the amount in the rest of the 70% of the ocean. Nature manages without our interference in cleaning up the oil.
There is effectively an oil spill every day at Coal Oil Point (COP), the natural seeps off Santa Barbara where 20 to 25 tons of oil have leaked from the seafloor each day for the last several hundred thousand years.
http://www.livescience.com/5422-natural-oil-spills-surprising-amount-seeps-sea.html
In the Gulf of Mexico, there are more than 600 natural oil seeps that leak between one and five million barrels of oil per year
http://en.wikipedia.org/wiki/Petroleum_seep