The lecturer and author, both discuss about the reasons of declining population of sea otters in the Western Cost of North America, from California to Alaska. The lecturer talks about the predation theory. She thinks that it is the main cause of declining population of sea otters. However, the author of the reading disagrees with the lecture. He thinks that, environmental pollution is the main reason of declining sea otters. Lecturer has also explained the reasons how predation theory seemed more likely to be the reason of declining sea otters.
First, According to the lecturer, predators are the cause of reducing population of sea otters. She mentions that, if otters are killed by the infections, then they can’t suddenly wash up. They could have found any dead sea otters or it could have created some odor off shore too. But, according to author, pollution is the only cause, as high level of chemicals is observed in the water sample of that area.
Second cause of reducing other sea mammals like whales is human hunter and not the pollution, lecturer says. She explains that, if whales are no more available, then orcas have to change their diet from larger mammals to smaller ones. However, author thinks that environmental pollution is the only reason of reducing population of other sea mammals too.
Third reason of declining population of sea otters is the accessibility of predators to the locations. Lecturer explained, Orca, because of their size cannot reach to the shallow and rocky areas where populations of sea otters haven’t declined. On the other hand, author mentioned uneven pattern of pollution hypothesis.
To sum up, lecturer doubts the reasons which author provided for declining of population of sea otters. As stated above, she thinks predation theory is the main reason of reducing population of sea otters.