Natural plankton respiration measured by INT reduction method from ice and interfacial samples collected during RRS Sir David Attenborough cruise SD035 in the Southern Ocean in February 2024 as part of the PICCOLO project v.2

Microbial community respiration (MCR) and the apportionment of this respiration to size classes is important for an understanding of the cycling of carbon through the marine foodweb and thus climate mediation. However, the proportion of MCR attributable to different size classes of plankton is not fully known. This dataset includes total and size-fractionated respiration rates determined as the production of formazan by the cellular electron transport system measured by the INT reduction method. Discrete interfacial seawater samples were taken from below floes 8 and 9 and ice samples were taken from free floating brown ice. These samples were taken by scientists from the University of East Anglia in February 2024 during the NERC-funded PICCOLO cruise SD035 in the Southern Ocean. Current version 2 reflects time corrections from previous submitted version.