Using complete sentences, describe the chain of events that leads to the eutrophication of water systems.

Phosphate detergents and chemical fertilizers that pollute the water provide nutrients for algae growth. The excessive algae growth consumes oxygen and promotes the growth of bacteria that feed on dead algae. The increased bacterial population consumes oxygen needed by plants and animals that normally live in the water system. These plants and animals die. Extreme eutrophication can lead to areas of water systems with no oxygen and no living organisms. These zones are called "dead zones."