Estimating the Organic Carbon Content of Phytoplankton From Cell Volume or Plasma Volume1

Equations for estimating the organic carbon in phytoplankton from cell volume or plasma volume are derived from original data on five species of diatoms and from data in the literature. Differences among species are important sources of error in such estimates. Plasma volume provides a more precise estimate of cell carbon in diatoms than does cell volume. Diatoms, because of their lower carbon per cell volume, should probably be treated separately from other phytoplankton in such computations.