Declining Sea Otter Summary

The professor talks about the real reason behind the declining of the sea otter,which is predation. He mentions three points that are the lack of dead sea otter in the beach, some animal chasing their diet , and location of sea otter makes them easy to hunt. The information he discusses is opposite the points in the reading.
First, the lecturer mentions that there is no dead sea otter body on the beach, that means the sea otter gets killed and eaten by a predator, not because of pollution , ON the other hand, the reading points out that the main reason is pollution, also, some experts test the water and find a high levels of chemicals that affect the sea otter.
Second, the professor explains that due to the lack of whales, some of the animals
that eat whales changed their diets, and he gives an example the orcas. However, according to the reading, the predator in that area is just to hunt large prey like whales not small one like the sea otter.
Third, the speaker makes the point that the pattern of sea otter decline according to the location. the populations of sea otter that located in shallow rocky are stable while the others which located in an area that easy to orcas to hunt them are declined. While in the reading, states that some locations are more contaminated than other, which explains the different in the sea otter population.