Just in Santa Barbara alone 10,000 barrels a day naturally seeps out of the ocean bed rock into the ocean. Natural gas seepage is probably an order of magnitude higher. When I was there studying geology I saw so many ignorant leftists who kept trying to blame all the tar on the beaches on the oil rigs. The reality is the oil rigs decrease the natural seepage by sucking up oil and natural gas thus helping to lower the reservoir pressure so seepage rates go down.
More oil drilling would mean less natural seepage and thus less natural oil contamination but, no, the environmentalists are totally against that in their ignorance.