Both the passage and the lecture are concerned with the decrease in sea otter population in areas of the Alaskan coast. The author of the passage claims that the decrease is due to pollution of the otters' environment. The professor refutes this point. He avers that the population decline originated in increased predator activity in these areas.
First of all, the author points out that there are notable sources of pollution in Alaska, such as oil rigs. Tests conducted on water samples from these locations have revealed high levels of chemicals that could affect sea otters. This point is challenged by the lecturer. He notes that
Secondly, the author contends that pollution is a reasonable explanation of the decline of other sea mammals' populations
First of all, the author points out that there are notable sources of pollution in Alaska, such as oil rigs. Tests conducted on water samples from these locations have revealed high levels of chemicals that could affect sea otters. This point is challenged by the lecturer. He notes that
Secondly, the author contends that pollution is a reasonable explanation of the decline of other sea mammals' populations