The relationship between nutrient status and chemical composition of Peridinium cinctum during the bloom in Lake Kinneret

Changes in water chemistry and the major chemical and elementalconstituents of Peridinium cinctum have been followed duringthe 1976 growth season (February-June) in Lake Kinneret. Thedecline of the bloom was not associated with changes in anysingle physical or chemical parameter of the lake water, althoughthe ambient N:P ratio was higher before the peak of Peridinium.Carbon, nitrogen and chlorophyll in the cells were almost constantover the growth season, averaging 48, 4 and 0.9% dry weight,respectively. There was an initial drop in cell phosphorus from0.7% to 0.2% dry weight which then remained stable after April.During the bloom period the carbohydrate and lipid content ofPeridinium decreased, nucleic acid increased, whereas proteinshowed no definite trend. The results suggest that (a) Peridiniumis not severely nutrient limited during most of the growth season;and (b) criteria based upon cellular composition used to definenutrient status in other groups of algae, may not be directlyapplicable to armoured dinoflagellates.