Ocean Acidification

Most of the experimental work on the effects of ocean acidification on the photosynthesis of algae has been performed in the laboratory using monospecific cultures. It is frequently assumed that the information obtained from these cultures can be used to predict the acclimation response in the natural environment. CO2 concentration is known to regulate the expression and functioning of the CCMs in the natural communities; however, ambient CO2 can become quite variable in the marine ecosystems even in the short- to mid-term. We propose that the degree of saturation of the photosynthesis for a given algal community should be defined in relation to the particular characteristics of its habitat, and not only in relation to its taxonomic composition. The convenience of high CO2 experiments to infer the degree of photosynthesis saturation by CO2 in the natural algal communities under the present ocean conditions, as well as its trend in a coming future is discussed taking into account other factors such as the availability of light and nutrients, and seasonality.

Mercado J. M., & Gordillo F. J. L., in press. Inorganic carbon acquisition in algal communities: are the laboratory data relevant to the natural ecosystems? Photosynthesis Research doi:10.1007/s11120-011-9646-0. Article (subscription required).