Monoculture experiments iodate-to-iodide conversion in phytoplankton between November 2016-October 2017.

The published dataset that is presented here includes 10 experiments on the conversion of iodate (IO3-) to iodide (I-) with monocultures of phytoplankton species obtained from the Roscoff culture collection (RCC) and the Bigelow National Center for Marine Algae and Microbiota (CCMP) including diatoms (<em>Chaetoceros gelidus</em> (RCC 4521), <em>Chaetoceros</em> sp. (RCC 4208), <em>Chaetoceros</em> sp. (CCMP 1690), prymnesiophytes (<em>Emiliana huxleyi</em> (RCC 1210 and RCC 4560), <em>Calcidiscus leptoporus</em> (RCC 1164), <em>Geophyrocapsa oceanica</em> (RCC 1318), <em>Phaeocystis</em> sp. (RCC 1725), <em>Phaeocystis anarctica</em> (RCC 4024)), and cyanobacteria (<em>Synechococcus</em> sp. (RCC 2366)). These species represent species from diverse types of climate zones (polar to tropical). All experiments were carried out in triplicate in 1L or 2L-glass flasks under ideal conditions regarding light, media, and temperature in controlled environments in culture rooms. All cultures were spiked with initial ambient IO3- concentrations as can be found in the marine environment (between 300 and 400 nM). We aimed at investigating all growth stages of each species, thus experiments were carried out until the senescence stage was reached. The cultures were samples semi-weekly to bi-weekly for fluorescence and total cell counts to evaluate their growth stage, and for iodine species to calculate rates of IO3- incorporation and I- production. The dataset that is presented here includes fluorescence, cell counts, IO3- and I- at each sampling day for each culture replicate. The data presented here were generated by Dr Helmke Hepach (University of York, now at GEOMAR Helmholtz Centre for Ocean Research, Kiel) under the supervision of Dr Claire Hughes (University of York). These experiments were part of the NERC project "Iodide in the ocean: distribution and impact on iodine flux and ozone loss" (NE/N009983/1, PI: Prof Lucy Carpenter, University of York).