On five occasions during the two year incubation of a subantarctic E. huxleyi culture (2015-11-20 to 2017-12-01), triplicate cultures of Now (11°C and pH 8.1) and Future (14°C and pH 7.8) cells, and also the crossover experiments - Future cells inoculated into Now medium and incubated under Now conditions (Future in Now), and Now cells incubated in Future medium under Future conditions (Now in Future) were prepared. Growth rates of each culture were monitored by measuring the in vivo chl-a of subsamples daily with a Turner 10AU fluorometer and calculating the least squares regression of the natural logarithm of in vivo fluorescence, versus time during exponential growth.

The mean growth rate of the first 5 semi-continuous Now and Future batch cultures were included at D30 in the manuscript figure for comparison with growth at the beginning of the experiment.The study was supported by Coasts and Oceans Centre (Strategic Science Investment Fund of the National Institute of Water and Atmospheric Research).