In this model food web the only feeding links are these: small fish eat algae; larger fish eat small fish; eagles eat larger fish. The larger fish are the only predator of the small fish in this web, and algae remain plentiful, so food is not a limiting factor here. If all the larger fish are removed and nothing else in this web changes, what happens to the small fish population?
Explanation
Removing the only predator the web states for the small fish means far fewer of them are eaten, so their numbers rise in this model. The choice in which the eagles switch to eating small fish fails, because the web states no feeding link between eagles and small fish.