title: Consequence of a sudden wind event on the dynamics of a coastal phytoplankton community: an insight into specific population growth rates using a single cell high frequency approach.
abstract: Phytoplankton is a key component in marine ecosystems. It is responsible for most of the marine primary production, particularly in eutrophic lagoons, where it frequently blooms. Because they are very sensitive to their environment, the dynamics of these microbial communities has to be observed over different time scales, however, assessment of short term variability is often out of reach of traditional monitoring methods. To overcome these limitations, we set up a Cytosense automated flow cytometer (Cytobuoy b.v.), designed for high frequency monitoring of phytoplankton composition, abundance, cell size, and pigment content, in one of the largest Mediterranean lagoons, the Berre lagoon (South-Eastern France). During October 2011, it recorded the cell optical properties of 12 groups of pico-, nano-, and microphytoplankton. Daily variations in the cluster optical properties were consistent with individual changes observed using microscopic imaging, during the cell cycle. We therefore used an adaptation of the size-structured matrix population model, developed by Sosik et al. (2003) to process the single cell analysis of the clusters and estimate the division rates of 2 dinoflagellate populations before, during, and after a strong wind event. The increase in the estimated in situ daily cluster growth rates suggest that physiological changes in the cells can prevail over the response of abundance.
authors.affiliation: Aix Marseille Université, Université de Toulon, CNRS/INSU, IRD, Mediterranean Institute of Oceanography, UM 110 Marseille, France.
authors.forename: Mathilde
authors.initials: M
authors.lastname: Dugenne
authors.affiliation: Aix Marseille Université, Université de Toulon, CNRS/INSU, IRD, Mediterranean Institute of Oceanography, UM 110 Marseille, France.
authors.forename: Melilotus
authors.initials: M
authors.lastname: Thyssen
authors.affiliation: Aix Marseille Université, Université de Toulon, CNRS/INSU, IRD, Mediterranean Institute of Oceanography, UM 110 Marseille, France.
authors.forename: David
authors.initials: D
authors.lastname: Nerini
authors.affiliation: Aix Marseille Université, Université de Toulon, CNRS/INSU, IRD, Mediterranean Institute of Oceanography, UM 110 Marseille, France.
authors.forename: Claude
authors.initials: C
authors.lastname: Mante
authors.affiliation: Aix Marseille Université, Université de Toulon, CNRS/INSU, IRD, Mediterranean Institute of Oceanography, UM 110 Marseille, France.
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Poggiale
authors.affiliation: Aix Marseille Université, Université de Toulon, CNRS/INSU, IRD, Mediterranean Institute of Oceanography, UM 110 Marseille, France.
authors.forename: Nicole
authors.initials: N
authors.lastname: Garcia
authors.affiliation: Aix Marseille Université, Université de Toulon, CNRS/INSU, IRD, Mediterranean Institute of Oceanography, UM 110 Marseille, France.
authors.forename: Fabrice
authors.initials: F
authors.lastname: Garcia
authors.affiliation: Aix Marseille Université, Université de Toulon, CNRS/INSU, IRD, Mediterranean Institute of Oceanography, UM 110 Marseille, France.
authors.forename: Gérald J
authors.initials: GJ
authors.lastname: Grégori
keywords: Berre lagoon; flow cytometry; high frequency; in situ growth rates; phytoplankton; wind