LabBench Activity

Measuring Primary Productivity

How can primary productivity be measured in an aquatic ecosystem? To answer this question, you must first recall the equation for photosynthesis. Type the equation here.

The equation for photosynthesis is:

Note: Because this lab focuses on dissolved O2, we don't include CO2 in our discussions. However, don't forget that CO2 plays a major role in both photosynthesis and cellular respiration.

Primary productivity can be measured in three ways:

  1. The amount of carbon dioxide used
  2. The rate of sugar formation
  3. The rate of oxygen production

In this laboratory, we will use the third method, the rate of oxygen production. Do you understand why this measurement will reveal primary productivity? If you aren't sure, look again at the definition of primary productivity and the equation for photosynthesis.