It is unclear why a slight decrease in calcium ion levels occurred during
exposure to 5 °C air. The pH remained stable during emersion and
the recovery phase, yet the calcium ion levels were only regained towards
the end of the recovery period. There was a quite a bit of variation
in calcium ion levels even in the pre-treatment measurements. The
samples were taken from different starfish at each time point, the size
range was constricted to medium stars (Fly et al., 2012), we did not record
the mass of the stars for each sample and it is possible there may
have been variation even within this size range.