Moreover, the trout has an indirect interaction with the starfish. Both species compete for the ghost shrimp as food. Any increase in the starfish population will decrease the shared food resource, thus, the trout population will indirectly decrease due to less food. As a result, if the starfish population increases, the trout population
is harmed. If the starfish population decreases, the trout population benefits.
Furthermore, the trout has another indirect interaction will algae. Since the ghost shrimp population relies on algae for food, any decrease in the algae population will cause an indirect decrease in the trout population. For example, if sections of the algae population are destroyed, the ghost shrimps will have less food to feast on, thus, the trout population will be harmed. In addition, if the algae population increases, the ghost shrimp population will increase as well, and the trout population will benefit.