Dissolved oxygen is one of the primary indicators of the quality of an aquatic environment. Oxygen enters water from the surrounding air, as a product of photosynthesis, and as a result of rapid movement of water. A Dissolved Oxygen Probe can be used in a wide variety of tests or experiments to determine dissolved oxygen concentrations (DO) and changes in dissolved oxygen concentrations.


In the Preliminary Activity, you will gain experience using a Dissolved Oxygen Probe as you determine the DO level of a water sample provided by your teacher.

After completing the Preliminary Activity, you will first use reference sources to find out more about dissolved-oxygen issues in the environment before you choose and investigate a researchable question dealing with dissolved oxygen.