Picophytoplankton Diversity and Photoacclimation in the Strait of Sicily (Mediterranean Sea) in Summer. I. Mesoscale Variations

Phytoplankton dynamics were investigated at the mesoscale in the northern part of the Strait of Sicily in July-August 1997 on fractionated samples (<3 µm and >3 µm) using high performance liquid chromatography (HPLC) pigment analysis and flow cytometry. Distribution, diversity and photoacclimation varied within the different water masses and features present at the time of sampling, including a surface filament of deep, cold water. Picophytoplankton (<3 µm) accounted for 80% of total chlorophyll on average and was numerically dominated by cyanobacteria of the genus Prochlorococcus, with an average concentration of 5.2 x 104 cell ml-1. The biomass and pigment diversity of the picophytoplankton was higher in the deep chlorophyll maximum (DCM) and was related to hydrological and biological features, while larger phytoplankton (>3 µm) appeared to respond to different cues. Chlorophyll pigment content per cell of Synechococcus, Prochlorococcus or picoeukaryotes was estimated by coupling pigment data with flow cytometric counts.

BRUNET Christophe;  CASOTTI Raffaella;  VANTREPOTTE Vincent;  CORATO F;  CONVERSANO F.; 

2006-11-21

INTER-RESEARCH

JRC35191

https://publications.jrc.ec.europa.eu/repository/handle/JRC35191,