Collecting data to calculate the primary productivity of an aquatic sample just got easier with our new Primary Productivity Kit. This kit contains seven bottles and stoppers designed for measuring dissolved oxygen (DO) in dark and light environments. The special shape of the bottles prevents air entrapment and makes it easy to collect data with the Vernier Dissolved Oxygen Probe.

The Primary Productivity Kit also includes four screens of varying length that wrap around the bottles, providing different light exposures for students to sample and compare to a bottle placed in the dark. As shown in the graph below, this makes it easy to conduct the classic primary productivity lab found in our Advanced Biology with Vernier, Biology with Vernier, and Investigating Environmental Science through Inquiry lab books.

The Effect of Light Exposure on Primary Productivity

The Primary productivity Kit also works well for inquiry-based labs; for example, a student can look at the effect of different nutrients on DO levels, or measure the primary productivity of different eutrophic samples. We have developed several inquiry-based labs using the Primary Productivity Kit.

One that you might consider is an investigation of the effect of light of different wavelengths on the primary production of green algae. Students expose separate samples of green algae to white, red, blue, and green 30W compact fluorescent bulbs for 24 hours. The bulbs were used with independent lamps placed strategically such that the samples of algae were only receiving light from one specific bulb. Each sample was placed 18 cm from the lamp source. The dissolved oxygen concentration was measured after this time according to the procedure listed on the Primary Productivity lab instructions.

The Effect of Light Wavelength on Primary Productivity

Students can observe the utilization of blue and red wavelengths over green wavelengths by the green algae and investigate further by mixing different wavelengths together to encourage an increase in primary production.