Question

What is the most likely explanation for the smaller size of the hypoxic zone in the year 2000? Select one: a. An increase in fertilizer dumping in rivers b. Decrease in the amount of sediments carried into the Gulf c. Decreased amounts of phosphorus and nitrogen in the Gulf d. Increased growth of phytoplankton

Answer 1

Ok, I'm sick and tired of incorrect verified answers and Yes the verified answer here is incorrect. The correct answer is "B." and here is why:

hypoxia: a condition of oxygen depletion in water

Now know this, oxygen depletion mainly occurs when dirt and soil that have been sprayed with agriculture fertilizers are introduced or enter a body of water.

Fertilizers are actually amazing on land and they improve the soil quality immensely, but in the water they promote the growth of phytoplankton. This in itself isn't so bad, but once the fertilizers wear off the plankton die and decay, which then in turn uses more oxygen.

Answer 2

The correction option is A.
Hypoxic zone refers to low oxygen areas in the oceans and large lakes. Hypoxic zone is always caused by large amount of excessive nutrients pollution that arise from human activities such as dumping of factory wastes and fertilizers in water bodies. These excessive nutrients usually reduce the concentration of oxygen in these water bodies.<span />