Answer: decreased primary consumers
Explanation:
A food chain is a linear sequence of transfer of food and energy when one organism is consumed by the other organism in an ecosystem. The energy among the organisms in a food chain is transferred from lower to higher trophic levels.
In the given food chain, the algae is the producer which is consumed by the populations of aquatic insects and water flies, these are the primary consumers. These primary consumers are consumed by the small fish therefore, the small fish is the secondary consumer.
The increase in the population of the small fish will limit the populations of aquatic insects and water flies which are primary consumers.
On the basis of the above description, decreased primary consumers is the correct option.
