Bluegills in a pond prefer to feed on large zooplankton, such as copepods.The zooplankton in turn feed on algae.The pond has a few bass, which feed on the bluegills.A farmer introduces a large number of additional bass, which decimate the bluegill population.Quickly, algal blooms threaten to overwhelm the pond.The control of algae in this pond is an illustration of a(n)
A) direct interaction, because it forms a straight line from bass to bluegills to copepods to algae.
B) direct interaction, because bluegills are directly controlled by bass.
C) indirect interaction, because no species directly controls any other.
D) indirect interaction, because algae are indirectly controlled by bass.
E) indirect interaction, because action by the farmer is required to control all populations.

Question

Quizplus · Accepted Answer

The introduction of additional bass caused a decrease in the bluegill population, which leads to an increase in the zooplankton population, which in turn feeds on more algae, causing algal blooms. This is an example of an indirect interaction, where the bass indirectly controls the algal population through their effect on the bluegill population. The option A is incorrect as it does not reflect the feeding relationships correctly, while option B is also incorrect as bass do not directly control the bluegills. Option C is not correct as there are interactions between the species. Option E is not correct as the farmer's action is not relevant to the question of the type of ecological interaction.

Bluegills in a Pond Prefer to Feed on Large Zooplankton