Figure 5.

Photophysiological responses by Ward Hunt Lake mats to osmotic stress. The mats were incubated at a range of increasing salinities, and the quantum yield ratio (F_v/F_m) was measured immediately (T₀), and after 8 and 24 h in 2010 and immediately (T₀) and after 4, 6, 24, and 48 h in 2011. The 2010 data are for the surface black layer (A) and the bottom green layer (B), and the 2011 data are for the surface black layer only (C). The horizontal dashed lines are for the mean F_v/F_m values calculated for all time intervals at salinity up to 10 mS cm⁻¹ (vertical dashed lines).