The zebra mussel is a shellfish native to europe. during the early 1900's, it was accidentally brought to the united states in the ballast of a ship traveling to the great lakes. it has no predators in the great lakes.

what impact are zebra mussels likely to have on food chains in the great lakes?
a) they will have no real effects on the food chain, since they are from europe.
b) they will compete with native shellfish and clams and hurt their populations.
c) they will allow fish populations to expand, because they will be used as food.
d) they will cause the entire food chain to crash, since they do not fit into the original food chain.