Ambient water temperature was lowest during the 35 C experiment
at 20.9 C while during both the 40 C and 43 C experiment,
ambient water temperature was 22.7 C due to natural increases
in ambient water temperature that unexpectedly occurred over
the experimental period. Light intensity was highly variable on a
day-to-day basis due to changes in cloud cover, making the daily
PAM responses highly variable. Furthermore, PPFD over the full
7 days for each experiment were also variable and on average, PPFD
was 8.8, 9.6, and 13.7 mol photons m2 d1 during the 35 C, 40 C
and 43 C experiments, respectively. Average instantaneous PPFD
during the period of elevated water temperature (and during the
photosynthetic measurements) was 388, 436 and 634 lmol photons
m2 s1 in the 35 C, 40 C and 43 C, respectively.