TOEFL integrated writing: The sea otter

Both the reading and the lecture discuss whether ''Sea otters'' population have dropped due to environmental factors like chemical pollution or it has been due to predators' attack. The reading explains this based on two theories and provides three reasons, notwithstanding the listener disregards this point provided in the reading, and develops other explanations.

In the first place, the reading says that sea otters have been affected due to chemical contamination around the Alaska's coast, this include oil rigs. Nevertheless, the listener doesn't agree with this idea, he thinks that there is not evidence to support the point that contamination has been the problem. He considers that in order to proclaim this theory as a valid, we should have observed a large numbers of sea otters dying at the same time, and this was not the fact.

The second, the reading posits that other mammals that share the region with sea otters have also been affected and died, this might be assessed as an effect evoked by pollution. Contrary to this point, the listener explains that this appears to be the consequence of hunting by whales, in other words whales have switched their diet and now prefer to eat small animals like sea lions. This change has been due to human intervention producing that their main source of food migrate to other places.

The third, the reading states that this drop in otters population have been uneven, meaning that some places have been more affected than others. With this in mind, the listener explains this and says that it clearly shows that it is the effect of whales predation, due to the fact that the places where otters were less affected are those where whales cannot have access.