Seasonal variation in protein: carbohydrate ratios in a subtropical estuarine alga, Gracilaria verrucosa, and the determination of nitrogen limitation status using these ratios

Increasing nitrate concentrations in a growth media led to increased specific growth rates and protein : carbohydrate
ratios in apical segments of Gracilaria verrucosa. The specific growth rates reached a maximum in tips
with protein : carbohydrate ratios of 0.4 1 or greater. The zone of transition, or critical protein : carbohydrate
ratio, appeared to be at 0.38 when specific growth rates reached a maximum. In a field population of Gracilaria verrucosa, the highest protein: carbohydrate ratios were found in the winter months during the time of maximal observed biomass.