The two pie charts compare percentage the of pollutants that entered a particular part of ocean in 1997 and 2007. Overall, the pollution from domestic sewage and offshore oil increased while there was a drop in the amount of other pollution.
The quantities of domestic sewage entering the ocean increased from 18% to 29% during this decade, becoming equal to the percentage of pollutants from air, which in turn showed only a minor change from 2007. 14 per cent of t of pollution offshore oil, which was about three times the figure a decade ago. was from
By contrast, industrial waste and marine saw a drop of 8% and 5% respectively during this period. The pollution from litter accounted for 4 per cent in 1997. However, it is interesting to note that there was no litter in this part of ocean in 2007. As to the amount of pollutants from air and farm waste, it was roughly unchanged.
To sum up, it is clear that the main pollutant came from the air in 1997, whereas the two major factors in 2007 were atmospheric pollutants from air and domestic sewage, which, if unchecked, can cause greater contamination in the long run.