The applicability of grain density autoradiography to the quantitative determination of algal species production: A critique

Abstract

Grain density autoradiography can be utilized to quantitatively determine the productivity of individual species in mixed phytoplankton assemblages but only after grain counts have been corrected for the effects of source geometry on efficiency as well as for the effects of spurious grain formation and erasure. The common simplifying assumption made by all workers to date, that the grain count over a cell is directly proportional to the cell’s radioactivity, is never realized with mixed species assemblages and such attempts at quantification are invalid. The procedure of apportioning total filterable radioactivity to the cells counted in autoradiographic preparations is also suspect. A method of data correction is presented which makes quantification feasible.