Question: As a result of human activity, many lakes in Florida have increased levels of nutrients that support algal growth. These algae grow very rapidly, then die and decompose. What impact does this overgrowth of algae most likely have on the lake ecosystem?

  Options: 
 A. The number of fish species increases.
 B. The volume of lake water increases.
 C. The buildup of bottom sediments decreases.
 D. The amount of dissolved oxygen decreases.
Answer: D