The two pie charts compare the percentages of contaminants that entered a specific area of the ocean between 1997 and 2007.
Overall, while the amount of air pollution, offshore oil and domestic sewage showed an upward trend, the remaining pollutants decreased. Additionally, air pollution was the most prevalent impurity in both years. In 1997, litter and farm waste were the least significant pollutants; however, after that, litter did not appear in this area in 2007.
Looking at the proportion of pollutants from air, its percentage accounted for 30% initially, then this figure dropped slightly to 29% in 2007. At the same time, the rate of domestic sewage increased the most sharply over 10 years, from 18% to 29% (which was the same as air pollution in 2007), and it became the major source of pollution. Furthermore, offshore oil accounted for 5% in 1997, and after 10 years, its percentage nearly tripled.
Moving on to the contaminants that lost their appeal, both farm waste and litter accounted for 4% in 1997, but the share of farm waste fell slightly to 2%, while litter was not recorded in this area in 2007. In the first year, industrial waste stood at 17% and it nearly halved by the end of the period. Besides that, the figure for marine pollution was the second highest, at about 22%, and it experienced a slight downward trend to 17% later.