TPO 35 Integrated Writing Task

The article is about three theories explaining the main cause of the extinction of a huge marine mammal known as Steller's sea cow once lived near Bering Island off the coast Siberia. However the professor refutes each of the author's theories.

First, the reading claims that the sea cows may have been overhunted by groups of native Siberian people. The professor refutes this point by saying that sea cows are huge and couple of sea cows could feed entire village for several months. Therefore it is highly unlikely to massive hunting occurred in the past by natives.

Second, the sea cow population may have become extinct because of ecosystems disturbances that caused a decline in their main food source, kelp. However, the professor says that if there was such disturbance happened near Bering Island it should affects other part of the ecosystem, such as whale. But the old reports from fishing ships suggest that they have not observed such scenario. Therefore, this theory of declining of kelp might have issues.

Third, theory suggest that the main cause of extinction of sea cows could have been European fur traders who came to the island after 1741. The professor opposes this theory by pointing to the fact that the sea cow population was already small, or declined when the European fur traders arrived. The sea cow population reached it peak hundreds years before this arrival and professor suggest that the true main cause was something going on before seventeenth century and he exonerate traders from the crime.