The bar chart compares the number of seals, whales and dolphins in body of salt water from 2006 to 2018 in order to illustrates how the marine life changed.
It is clear that the population of dolphins grew over the period shown but there is a fall for seals and whales in 2010 and 2014, respectively. Although seals had the most inhabitant in sea in 2006 but the dolphins caught this position in 2018.
To comparison between the first year of period and the last, the figure for seals did not change dramatically just increased nearly 2 units that was 42 million. As same as seals, the population of whales rise by similar amount from around 22 to 24 million. In the other hand the number of dolphins rose significantly to peak of about 49 million, which was almost 16 million in 2006.
In 2010 the number of three kinds of the animals almost remain close to each other between 20 and 23 million. Seals and dolphins saw approximately 10 units rise in number of population in 2014, whereas whales’ crowd declined from almost 23 to 20.