SEA OTTERS TPO 10

The reading passage and lecture are about the declination of sea otters, small mammals live in water. The author presents possible reasons to as what caused sea otters to decline. However, the lecturer casts doubt on each of the explanations presented in the article. She is of the opinion that sea otters decline has been caused by predation.

To begin with, the author argues that one of the reasons of sea otters declination is pollution. He states that increased number of chemicals in water could decline otter's resistance to deadly infections and cause their deaths. The lecturer, however rebuts this by mentioning that pollution theory is weakened mainly by the fact that there was no deaths of sea otters found along the Alaska beaches. Furthermore, she points out that if an otter is killed by a predator, it will not be found on shore.

Secondly, the authors contends that sea and sea lions along with other mammals are declining as well, which is the indication that otters were affecting other mammals too. It is mention in the article that orcas could have the same effect, but they usually prefer large prey. This point is challenged by the professor. He mentions that whales disappear from the place because of human hunters. So, orcas changed their diet and started to feed on smaller mammals instead. She elaborates that orcas causing decline of seals, sea lions and otters.

Finally, the author posits that otters decline due to their uneven pattern. Some experts suggest that environmental factors might have created uneven concentrations of pollutants. The lecturer, on the other hand, feels that it basically depends on the otters location if its convenient for orcas. She puts forth the idea that orcas are so big that they can not reach to shallow locations where sea otter populations have not decline.