NEW PHYTOPLANKTON SINKING RATE METHOD SUITABLE FOR FIELD USE

This work describes methodology developed to measure sinking rates of natural phytoplankton assemblages in the field. The technique is based on detection of radioactively (14C) labeled phytoplankton acquired from a productivity-type incubation. Evidence is presented to illustrate the technique's capability, accuracy, sensitivity, correlation with direct microscopic observation of cells, and stability suitable for shipboard use. Data show the sinking rate analyses of laboratory and natural populations, both in the laboratory and aboard ship. The technique circumvents several technical and theoretical problems that previously prohibited accurate sinking rate assessments of natural phytoplankton populations. © 1979.