A disease caused the population of small planktivorous fish in the region to sharply decline. How will this situation affect the competition for food in the region? Consider direct and indirect effects.

This situation would lead to increase in price of this kind of food and increase in demand of other close substitutes.

Explanation:

With the decrease in the small planktivorous fish in the region would definitely affect the situation of food in that region because the demand would be high but the supply would be less. Thus the price of this kind of fish will increase.

The other effects of this situation would be increase in the demand of the other close substitutes of this kind of fish in this region for the consumption of the people.

The zooplankton population may rise because the small planktivorous fish eat them for food. There also may be more phytoplankton for bivalves and small invertebrates because there will be less competition for these food resources from small planktivorous fish. But gulls, terns, large fish, and wading birds will have much more competition for food, both interspecific and intraspecific. This competition can indirectly affect the food supply for large carnivorous birds, such as bald eagles and ospreys. If the large fish don't have enough food to survive, their populations may also decline, which will decrease the food supply for these larger carnivores.

Explanation:

answer from Plato