Effects of Nitrates and Phosphates on Aquatic Ecosystems


Liliette Guzman

East Side Middle School

Summer Research Program for Science Teachers

August 2012

Subject: General Science, Biology

Grade Level: 6-8

Unit: Ecology

Time required: 1, 45 minute class period


Activity Overview:  Students now know that plants produce the food that fuels the rest of life on Earth. Plants need multiple inputs to undergo photosynthesis, like Nitrates and Phosphates, for nutrients.


Objectives: (With correlation to NSE 5–8 Content Standards)

1.                  Students think critically and logically to relate evidence to explanations. (Inquiry: 1)

2.                  An organism regulates its internal environment by sensing the external environment and changing its physiological activities to keep conditions within a survival range. (Life Science: 3)

3.                  Populations of organisms can be classified by the function they perform in an ecosystem. Plants are producers, which produce food for their own energy needs. (Life Science: 4)

Key Vocabulary:

Nitrates, phosphates, photosynthesis, producer



For class

Effects of Nitrates and Phosphates video


For each student

Student Sheet, “Nitrates and Phosphates”



1.  Give students each a copy of the Student Sheet.

2.  Have students complete Part 1 as a, “Think, Pair, Share”.

3.  Read the directions for Part 2.  Show video, “Effects of Nitrates and Phosphates”.  Stop video after each section to allow students to write down their response.  You may have to replay video for students.

4.  Share out responses as a class and discuss how aquatic ecosystems may respond to increased amounts of Nitrates and Phosphates.

5.  Have students complete Part 3 for homework and review next day.