The pie charts illustrate the percentages of six different sources of pollution affected a particular part of ocean from 1997 to 2007.
As an overall overview, the percentage of air pollution was the highest affecting the ocean over the whole period, whereas the proportion of litter was the lowest among the remaining pollutants. Regarding the remaining sources of pollution, they had distinct percetanges of effect on the ocean.
According to the pie charts, pollutants from air showed significant proportions in both years (1997 and 2007), at 30% and 29%, respectively. In contrast, the percentage of litter which polluted the ocean was 4% in 1997, decreasing to 0% by 2007. As for the figure of polllution of domestic sewage, it was 18% in 1997; however it increased considerably, reaching 29% by 2007. With regard to offshore oil, it polluted the ocean with a percentage at 5% in 1997, yet it surged to 14% in 2007.
Turning to the marine pollution that polluted the ocean, it experienced a proportion at 22% in 1997, declining to 17% by 2007. Meanwhile industrial waste started at a figure of 17% and dipped to 9% by 2007. In the case of the pollution of farm waste, it polluted the ocean with a percentage at 4% in 1997, decreasing to 2% by 2007.