The synergic effect of nutrients and light intensity affects the dominance of bloom-forming cyanobacteria in natural phytoplankton assemblages

AGUILERA ANABELLA; LUIS AUBRIOT; RICARDO ECHENIQUE; GRACIELA SALERNO; BONILLA SYLVIA

Simposio; 15th International Symposium on Phototrophic Prokaryotes; 2015

Using aquatic microcosms, we performed eleven-day experiments todetermine the effect of light intensity and nutrient enrichment on naturalphytoplankton assemblages, dominated by filamentous cyanobacteria. Toassess the effect of both factors, two nutrient conditions [supplemented withK2HPO4 (+P) or with +P and NaNO3 (+NP)] and two light intensities (40 and80 µmol photon m-2 s-1) were assayed in a fully factorial design.Phytoplankton growth was monitored daily by optical density. Speciesidentification, counting and biovolume determination were performed every 3days.