Steelhead fish are predators of predatory insects, which in turn feed on midge larvae. The midge larvae feed on algae. By indirect effects, a reduction in the number of steelhead fish should lead to a(n) _______ in midges and a(n) _______ in algae.
A) increase; increase
B) increase; decrease
C) decrease; increase
D) decrease; decrease

Question

Quizplus · Accepted Answer

Steelhead fish are predators of predatory insects, which in turn feed on midge larvae. The midge larvae feed on algae. By indirect effects, a reduction in the number of steelhead fish should lead to a decrease in the number of predatory insects, which would lead to an increase in the number of midge larvae. This would then lead to a decrease in the number of algae, as the midge larvae would consume more of it.

Steelhead Fish Are Predators of Predatory Insects, Which in Turn