Question

The zebra mussel is a shellfish native to Europe. During the early 1900s, it was accidentally brought to the United States in the ballast of a ship traveling to the Great Lakes. What impact are zebra mussels likely to have on food chains in the Great Lakes?

a) They will be outcompeted by higher trophic levels in the food chain.
b) They will have no real effects on the food chain since they are from Europe.
c) They will allow fish populations to expand because they will be used as food.
d) They will compete with native shellfish and clams and cause a reduction in their populations.

Answer 1

Zebra mussels in the Great Lakes compete with native species, reducing their populations. They have economic impacts and alter lake ecology but can benefit some fish species by improving water clarity.

Step-by-step explanation:

The zebra mussel is a non-native invasive species that is likely to impact food chains in the Great Lakes by competing with native shellfish and clams. This competition can lead to a reduction in native species populations. As filter feeders, zebra mussels improve water clarity, which can enhance plant growth and possibly benefit some fish species. However, their presence has also resulted in significant economic damage due to maintenance costs for water facilities and altered lake ecology.