Nutrient availability influences maximum biomass, speciation, cellular composition, and overall phenology ofArctic spring ice algal blooms. However, how ice algae obtain nutrients from their environment is not well understood.Previously documented positive relationships between sea ice nutrient concentrations and algalbiomass implied that ice algae maintain an intracellular nutrient pool. Here, we provide direct evidencethat sea ice diatoms store intracellular nitrate + nitrite and silicic acid well above that available in their ambientenvironment. Differential retention of intracellular pools released during standard melt processing techniquesled to an increase in the apparent dissolved N:Si ratio measured in ice melt samples that likely influenced interpretationsof Si-limitation in some previous studies. It is hypothesized that the ability of ice algae to storeintracellular nutrient reserves represents a beneficial adaptation for ice algae to extend blooms under a periodictidal-pulsed flux of nutrients to the ice bottom environment.