@article{JRC32910, address = {Duebendorf (Germany)}, year = {2006}, author = {Eker Develi E and Kideys A and Tugrul S}, abstract = {The effects of nitrate, ammonium and phosphate on the abundance, chlorophyll a content (chl a), in vivo fl uorescence, particulate organic carbon, nitrogen, phosphorus and cell morphology of the diatom Skeletonema costatum, the dinofl agellate Prorocentrum micans and the coccolithophore Emiliania huxleyi were investigated in the laboratory. The carbon:chlorophyll a ratio (as weight), a parameter often used in productivity estimates, differed substantially among the three species as well as at different nutrient concentrations at the end of the exponential growth phase. The cell chl a content was higher in the earlier phases of growth in all three species in agreement with previous investigations. Average chl a content per cell during the experiments was higher in P. micans (8 pg) than in S. costatum (0.4 pg) and E. huxleyi (0.2 pg). However, chl a content per unit volume was higher in E. huxleyi (~15 fg μm–3) than in S. costatum (~7 fg μm–3) and P. micans (~1 fg μm–3). Prorocentrum micans cultures reached the highest total biovolume (74 mm3 L–1 and was 3 and 5 times higher than S. costatum and E. huxleyi cultures, respectively) under high nutrient concentrations. Nevertheless, total chl a concentration of S. costatum culture was almost twice higher (122 μg L–1) than that of the other two species at the end of the exponential growth phase. Phosphate consumption by S. costatum occurred at higher rates compared to the other two species during the experimental period, probably showing that this nutrient was more favourable for this species. Our fi ndings from these laboratory experiments emphasize that chl a values in the natural habitat may not accurately indicate actual phytoplankton biomass. }, title = {Effect of Nutrients on Culture Dynamics of Marine Phytoplankton}, type = {}, url = {}, volume = {68}, number = {1}, journal = {AQUATIC SCIENCES}, pages = {28-39}, issn = {}, publisher = {BIRKHAUSER VERLAG AG}, doi = {10.1007/s00027-005-0810-5} }