SETCOL — A Technologically Simple and Reliable Method for Measuring Phytoplankton Sinking Rates

Abstract

A simple and reliable method for measuring the sinking rate of phytoplankton is described. This technique is suitable for both heterogeneous field populations and unialgal in vitro cultures. The procedure involves use of settling columns initially containing a uniformly mixed population of cells, and calculates a sinking rate based upon the change in vertical distribution of cells after a given time. The sinking rate calculation, though simple, is couched within a sound theoretical foundation. The biomass index used is optional and can be selected to focus on various parameters of interest. Sinking rates and flux values for particulate C, N, P, Si, chlorophyll, or pheopigment can be obtained simply by assessment of the biomass variables in those terms.Key words: phytoplankton, sinking, methodology, particulate flux, sedimentation