What are the effects of elevated CO2 conditions on Dunaliella tertiolecta?

Maira Nieto and Katherina Schoo

Shannon Point Marine Center, Western Washington University


Our oceans are important for reasons ranging from recreational value to predicting weather patterns. Unfortunately, the CO2 that is released into the atmosphere from agricultural and industrial activities increases every year, changing the chemistry of the seawater. These changes have a direct impact on marine phytoplankton that are the primary producers in marine food webs. The carbon to nutrient stoichiometry and fatty acid content of phytoplankton often defines food quality. With increasing CO2 in our oceans, the effects of increased carbon availability on phytoplankton need to be investigated.

We studied the effects of different CO2 levels (400, 800, 1200 ppm) on growth and biochemistry of the marine phytplankton Dunaliella tertiolecta. The 400 ppm level was chosen because that is what we are experiencing today, 800 ppm is an intermediate level expected in the year 2030, and 1200 ppm is expected in the year 2050 if we continue on the business-as-usual path (IPCC 2014).

It is hypothesized that an increase in carbon availability may alter the growth and biochemistry (nutrient content, lipids) of D. tertiolecta and change its food value to higher trophic levels. The result could be larger populations of phytoplankton with higher fatty acid content, but lower nutritional value. It is also hypothesized that higher cell densities and carbon content per cell will be found at 1200 ppm because there is more carbon available for use.


Intergovernmental Panel on Climate Change (IPCC) (2014) Climate Change 2014: Synthesis Report.

Page Updated 05.20.2015