tpo 26 Integrated task

The article provides three reasons to explain why the invasion of zebra mussel, a freshwater shellfish native to Eastern Europe, cannot be stopped and it has serious threat to freshwater fish population I the North America. The professor opposes this concept and says that there are ways to control the spreading of zebra mussel and it does not pose any threat on fish population.

first, the reading states that the history of the zebra mussel' spread from Eastern Europe to the whole of Europe by the ships suggests that the invasion to America would probably be unstoppable. The professor counters this point and explains that they could not stop the invasion on the past because they did not have enough knowledge but not there are effective ways to prevent its invasion. He mentions that travelling ships cross the ocean take fresh water that are full of mussels, they can be required to discharge the fresh water and replace it with salt water which disable mussel to survive in.

Second, the author points out that zebra mussel can dominate the area after invasion because they have a high rate of reproduction and they do not have natural predators. The professor casts doubt this point and demonstrates that birds will discover quickly that there is a new source of food and they will switch to eat zebra mussel and they are perfect in eating them. Therefore, it is not likely to dominate a new place.

The reading claims that zebra mussels might lead to decline in fish population because they eat their food which is plankton. Although the professor illustrates that they can provide nutrients for fish on the bottom of the ocean so that many fish can grow. As a result, even thouth they may affect some fish population on the surface, they can flourish other fish on the deep ocean and the fish population may increase.