FLOW CYTOMETRY PATTERNS OF AUTOTROPHIC PICOPLANKTON FROM EUTROPHIC SHALLOW LAKES

HUBER, P.; QUIROGA, V.; KRANEWITTER,V.; TORREMORELL, A.; LAGOMARSINO, L.; LLAMES, M.; UNREIN,F.

Granada

Congreso; Aquatic Sciences Meeting; 2015

ASLO

Picophytoplankton from eutrophic shallow lakes are generally underrepresented in globalmodels. Here we used flow cytometry to map phytoplankton in six eutrophic Pampeanshallow lakes at different spatiotemporal scales. Besides cell number we analysed cytometricdiversity, light scatter and fluorescence. High-frequency sampling in the turbid lakeChascomús revealed that relative side-scatter (SSC) of picocyanobacteria (Pcy) andpicoeukaryotic algae (Peuk) was synchronized with the daily light cycle, and that redchlorophyll fluorescence (FL3) was negatively correlated with turbidity, suggesting a rapidacclimatization to changes in underwater light climate. Long-term study in the same lakeshowed that picophytoplankton was permanently dominated by Pcy (ca. 90%), with a clearseasonality. Contrarily to other temperate lakes, maximum values were observed in winterspringand minimum during summer. At a regional scale, Pcy dominated picophytoplankton inall lakes, excepting some turbid lakes dominated by large filamentous cyanobacteria wherePcy were almost absent. Marked changes in cytometric diversity (sensu Li 1997)were observed between vegetated and phytoplankton-turbid shallow lakes.Presentation Choice: PosterSession Choice 1: 015Session Choice 2: 139Confirmation #: