Percentages of Oil Entering the Ocean About 380 million gallons of oil enter the world's oceans and coastal waterways each year from natural and human sources. This illustration shows the approximate worldwide percentages arriving from each source. The relative inputs of oil can vary significantly in different parts of the world. The percentages for transportation include oil lost specifically in oil/petroleum commerce (tankers, pipelines, etc.), as well as the normal operation of all other sea-going vessels. (Illustration by Jack Cook, WHOI)
