The lecturer and the reading passage discuss the zebra mussel, a freshwater shellfish. The professor claims that the invasion of the zebra mussel can be stopped now with advanced knowledge and does not make any harmful effect. This counters the reading passage’s claim that this invasion cannot be stopped and can create a severe threat.
To begin with, the speaker asserts that the invasion by human transportation can be stopped. The zebra mussels can survive in the ballast water of the ship, which needs to take on balance its cargo which the ship carries to balance its cargo. While people filled this ballast water with fresh water in the past, people now fill it up this water with salty water, in which zebra mussels are not able to survive. Because of this, the zebra mussels cannot spread anymore by ballast water. This contradicts one of the reading passage’s claim that the invasion of the zebra mussel could be via ballast water is unstoppable.
On top of that, the speaker claims that the zebra mussels will have a lot of predators soon in their new habitats. Although birds do not eat the zebra mussel in the beginning, they will be able to switch and change their food source into and soon prey on the zebra mussel. Because of this, the population of the zebra mussel will decrease. This is the opposite of the reading passage’s claim that the zebra mussel can dominate in their new habitats because there are no natural predators.
Finally, the speaker argues that the zebra mussels are unlikely to cause a reduction in the all every fish population in their new habitats. Some fish compete for food source with the zebra mussel and their population will be able to possibly decrease. However, other fish, which live in deep lake, will get benefit from the zebra mussel by providing because it provides nutrients. This refutes the reading passage’s claim that the zebra mussels are likely to cause a reduction in the all every fish population in their new habitats.
Writing 0-30 scale
Fair (21-25)
두 passage의 내용을 충실히 요약하고 정리했습니다. lecture가 reading passage를 어떻게 반박하는지도 잘 설명합니다.
다만 표현이 어색하거나, 내용을 충분히 전달하지 못하거나, 의미가 의도한 것과 달라지게 표현한 부분이 있습니다.