Phytoplankton dynamics in the Mediterranean Sea: approaches using high frequency measurements, modeling, and Bayesian statistics.

Summary All marine ecosystems rely on phytoplankton to convert atmospheric carbon into organic matter through the process of photosynthesis. Two approaches are presented to measure phytoplankton productivity by taking into account the temporal evolution of cell size. In essence, they reflect the progressive assimilation of inorganic carbon during the life cycle of a cell and its reallocation from one generation to the next at the time of cell division. In the natural environment, this carbon flow depends on phytoplankton communities and their sensitivities. The observation of phytoplankton in a disturbed environment on a small scale of time and/or space is essential to anticipate climate change. The Mediterranean Sea in particular is likely to undergo rapid changes in its climate and the populations it supports. In the Mediterranean Sea as in the global ocean, measurement campaigns are the basis of scenarios that reflect the impact of the environment on the functioning and capacity of phytoplankton to buffer gas emissions from human activity.