Mesocosms experiment in details

MedSeA Villefranche mesocosm experiment will take place from February 1st to March 24th at the Observatoire d’Océnaographie de Villefranche (CNRS-UPMC) that is located close to Nice (French Riviera). The Bay of Villefranche despite being close to Nice, the seawater is relatively clean. During this period nine mesocosms will be deployed just in front of the marine station.

A mesocosm is like a strong plastic bag which can be filled with the surrounding water and closed at the bottom. We will therefore enclose 50,000 liters of seawater and all the microorganisms that are living at the time of the experiment in the Bay of Villefranche. Then we will be able to study how the plankton communities (phytoplankton, bacteria, viruses), nutrients and other chemical products will respond to future ocean acidification. When all the bags (mesocosms) will be closed, Carbon Dioxide (CO2) level will be increase simulating future levels of CO2. To do so, in three mesocosms, CO2 concentrations with present values (~350 ppm) will be maintained and will be used as controls. The six other mesocosms will receive some CO2 saturated seawater in order to reach different CO2 values as expected for the next century.

The set-up of the mesocosms will take around two weeks and will be done by the Laboratoire d’Océanographie de Villefranche (LOV) team which is in charge of the organization of this experiment in the frame of MedSeA project. For the following 4 weeks, scientists from many disciplines will take samples. The list of the parameters measured during the experiment is available here. In total, for this experiment, scientist from 6 institutes and countries wil be present.