Question: An increase in phosphate levels in a lake increases the population of algae in the lake. Increased algae blocks sunlight into the lake and results in a decrease in dissolved oxygen in the lake's water. Which of the following should be expected as a result?

  Options: 
 A. Plant populations in the lake increase.
 B. More predatory birds feed on lake animals.
 C. Phosphate levels in the lake decrease.
 D. Fish populations in the lake decline. 
Answer: D