Phytoplankton Abundance and Biomass Measured during the JGOFS Equatorial Pacific Process Study

During the fourth cruise (TT012), data were collected at 5 stations along 140 deg W longitude from 17 deg S latitude to the equator. Samples in a vertical profile were collected using the CTD rosette water sampler for the measurement of phytoplankton abundance and biomass. Dinoflagellates, diatoms, diatom tests (organism dead, containing no protoplasm), coccolithophores, and "other" phytoplankton were enumerated.

Abundances and biomasses of each of the above groups (in addition to total phytoplankton) were measured. Abundance was measured in cells/liter, and biomass was measured in picograms carbon/liter. In addition, the relative abundance of diatom cells was reported as the percent cell numbers of taxa in total visible diatoms under a light microscope (~2 microns).

The diatom relative abundance was reported for bicapitate Nitzschia, other Nitzschia and Pseudoeunoita. The data is public domain and can be retrieved on-line at "usjgofs.whoi.edu/jg/dir/jgofs/" [The information in this summary was derived from the JGOFS World Wide Web pages.]