TPO-10

The article states that the sea otters population of the Alaskan Coast declined because of the pollution hypothesis and provides three reasons of support. However, the professor says that the predation hypothesis is most likely caused the population of the sea otters have been declined and refutes each of the author’s reasons.

First, the reading states that the pollution seemed the more likely caused because along the Alaskan coast there was a lot of industrial chemical pollution sources, such as oil rings. The professor refutes this point by explaining that the pollution theory is weakened because no one can really find any dead’s sea otters washing off on Alaskan beaches. However, the predation theory well explain this point, if an otters are killed by a predators, its eaten immediately and can not be wash up on the shore.

Second, the article claims that the pollution affects the entire ecosystem by declining other sea mammals such as seals and sea lions along the Alaskan coast. In contrast, the professor stating that the sea mammals that mentioned in the reading declined because of the large predator such as Orcas. Orcas prefer to hunt whales but the whales have essentially disappeared from the area because whales have been hunted from people. So, the Orcas have had to change their diet to survive and hunt other types of sea mammals.

Third, the author posits that the pollution theory also explains the uneven pattern of otter decline; some Alaskan locations the otter population declined greatly and while at others they remained stable. The professor contrasts this point by saying that the uneven pattern of otter decline better explained by predation theory. Otter’s population in areas where Orcas are predominant is lower than their population in shallow rocky areas that Orcas cannot reach.