As the algae and other plants begin to die, they cause the bacterial population to explode. the bacteria exhaust the supply of dissolved oxygen needed by animals living in the water. what will happen to the minnow population?

The population of these fish will decrease, because they will end up dying from lack of oxygen.

Explanation:

The low concentration of oxygen in the water is very harmful to fish.

Fish, when exposed to a low concentration of oxygen in the water, even for a short period of time, do not face so many problems as long as other water quality parameters such as pH, ammonia, and nitrite are at acceptable levels. However, a permanent value below 60% saturation is intended to cause problems in fish health. Most survive a few days with a saturation of 40%, but if the oxygen concentration drops quickly, the fish will begin to feel the effects of the lack of oxygen and will eventually die.

more words for this could be abiotic and biotic

abiotic: living organisms within an ecosystem

biotic: non-living organisms within an ecosystem

i would think a oil tanker that has leaked in a bay