How does a lack of dissolvable oxygen in waterways affect aquatic biodiversity?

I think ‘there will be less oxygen available for the aquatic life due to the microbial activity’. Too much microbial activity utilizes the oxygen dissolved in the water hence making the waters anoxic. This occurs especially after algae blooms. When the algae grow exponentially and later die, microbes that oxidize the organic matter for energy utilize the oxygen and cause dissolved oxygen in the water to deplete. This hence suffocates other aquatic life.

(This is what my sister sayed so I put it down)

Explanation:

answers: When dissolved oxygen becomes too low, fish and other aquatic organisms cannot survive.

explanation: The colder water is, the more oxygen it can hold. As the water becomes warmer, less oxygen can be dissolved in the water.

the answer is d (apex) good luck : ))

i think the answer is gold im not entirely sure