TOEFL integrated writing: The sea otter

The article claims that the pollution hypothesis is the main cause of declining of otter population and provides three reasons to support. However, the professor explains that it is the most likely to be the predator theory is the cause and refutes each of the author's reason.

First, the reading states that there are a lots of industrial chemicals along Alaska cost that cause the dead of the sea otter. In the other hand, the professor says that pollution is a weak point and opposes this by saying if there is any infection by pollution, they must find the dead bodies of the otters. Also, he explains that if otters were attached by hunters, their bodies must be seen on the shore.

Second, the author try to confirm this hypothesis by pointing to the declining of other sea animals like seals and sea lions due to pollution. Conversely, the professor refutes this by saying that the main cause is due to orcas predation. He explains that they have to find their diet to survive.

Third, According to uneven pattern discussed in the reading, the professor states that this is due to localization of the otter. They greatly decrease if they are found in a place easily reached by orcas. As orcas can not reach them in shallow places because of their large size.