Purpose: To relate the physical and chemical properties of water to a water pollution issue.
Summary: In this exercise, students will measure the temperature and dissolved oxygen of a stream and discuss what this information can tell us about possible pollution problems.
Background: During this activity students will investigate two properties of water in a stream – the temperature and the concentration of dissolved oxygen in the water. Students will explore how natural influences, human activities and pollution may cause these parameters to change.
Temperature and oxygen were chosen for this activity because they are easy to measure, the causes of change are both varied and easy to understand, and also the two properties are related to each other. Fish and other animals living in water can be harmed by high temperatures and low oxygen concentrations.
As water gets warmer the “saturation concentration” for oxygen gets lower – in other words the warmer the water, the less oxygen it can hold. Therefore, when water temperatures increase, fish are often hit with a double whammy of low oxygen as well.
Materials:
Documents:
Stream side Science Manual
When Things Heat Up Student
Presentations: None
