It is highly probable that long before man arrived on earth natural petroleum seeps, both onshore (littoral) and offshore, were polluting the beaches and the oceans. This is still going on. The best known example today is in the Santa Barbara (California) Channel where on an average day from 50 to 70 bbl of oil seeps into the ocean off Coal Oil Point. Some years ago Pitch Lake on Trinidad supplied a stream of asphalt that poured continuously into the Gulf of Paria. This flow has ceased, because mining of the asphalt has lowered the lake below its outlet.

Smaller seeps are worldwide in their occurrence, and no doubt many offshore seepages remain to be discovered. Therefore, man should not be given all the blame for beach and ocean pollution. However, the important point is that oil spills and many seeps are reducible. Man-made pollution already is being diminished by voluntary and mandatory controls, and by the development of sophisticated techniques and equipment to clean up the oil. Natural seepages on land have diminished as wells have drawn down the hydrocarbons in the reservoir. This has occurred at such famous seeps as Kirkuk in Iraq and Mene Grande in Venezuela. No doubt, at least some offshore seepages can be reduced in the same way.