Here we present data of phytoplankton pigment and flow cytometry (FCM) data from initial (T0) and final (T24) samples obtained from serial dilution grazing experiments set up with surface mixed layer water from subantarctic waters across the Campbell Plateau region southeast of New Zealand. Experiments were incubated onboard of the RV Tangaroa using deck flow-through incubators simulating in situ light and temperature conditions.