Question

The natural process of eutrophication is accelerated when inorganic plant nutrients, such as phosphorus and nitrogen, enter the water from sewage and fertilizer runoff. Eutrophication caused by humans is called artificial eutrophication. Fertilizer from farms, lawns, and gardens is the largest source of nutrients that cause artificial eutrophication.

Phosphates in some laundry and dishwashing detergents are another major cause of eutrophication. Phosphorus is a plant nutrient that can cause the excessive growth of algae. In bodies of water polluted by phosphorus, algae can form large floating mats, called algal blooms. As the algae die and decompose, most of the dissolved oxygen is used and fish and other organisms suffocate in the oxygen-depleted water.

IDENTIFYING MAIN IDEAS:

In the space provided, write the letter of the term or phrase that best completes each statement or best answers each question.

_____ 1. Which of these are examples of inorganic plant nutrients?

a. eutrophication and oxygen

b. phosphorus and nitrogen

c. oxygen and algal bloom

d. farms and lawns

_____ 2. Eutrophication caused by humans is called

a. artificial eutrophication.

b. algal bloom.

c. phosphates.

d. fertilizer.

_____ 3. Which of the following is the best statement of the main idea of this passage?

a. Decomposing algal blooms deplete oxygen from bodies of water.

b. Fertilizer runoff causes artificial eutrophication.

c. Artificial eutrophication damages bodies of water.

d. Phosphates in detergents are the major cause of eutrophication.

VOCABULARY DEVELOPMENT:

Read each question and write the answer in the space provided.

What is an algal bloom



Remember that eutrophication is the natural process by which a body of water gains an abundance of nutrients. Explain the distinction between eutrophication and artificial eutrophication.



RECOGNIZING CAUSE AND EFFECT:

Read each question and write the answer in the space provided.

Artificial eutrophication is caused by:



Artificial eutrophication happens when:

Answer 1

IDENTIFYING MAIN IDEAS

1. b. phosphorus and nitrogen

2. a. artificial eutrophication

3. c. Artificial eutrophication damages bodies of water.

VOCABULARY DEVELOPMENT

What is an algal bloom?
- A large, rapid growth of algae that forms thick floating mats on the surface of a body of water, usually caused by excess nutrients.

Explain the distinction between eutrophication and artificial eutrophication.
- Eutrophication is the natural, gradual enrichment of a body of water with nutrients over time. Artificial eutrophication is the same process accelerated by human activities (e.g., fertilizer and sewage runoff, phosphates in detergents) that add excess nutrients quickly.

RECOGNIZING CAUSE AND EFFECT

Artificial eutrophication is caused by:
- Inorganic plant nutrients (mainly phosphorus and nitrogen) from human sources such as fertilizer runoff (farms, lawns, gardens), sewage, and phosphates in detergents.

Artificial eutrophication happens when:
- Excess nutrients enter a water body, causing algal blooms; when the algae die and decompose, decomposition uses up dissolved oxygen, leading to oxygen depletion and the suffocation of fish and other aquatic organisms.