where is the maximum fluorescence and is the minimal fluorescence, which is obtained when emitted a low intensity measuring light, which is measured momentarily before the saturation pulse is applied (Figueroa et al., 2017; Houliez et al., 2013; Le Rouzic, 2012). Phycocyanin detection was performed according to Bennet and Bogorad (1973), in which the water sample was concentrated in a centrifuge, the supernatant was removed, and the concentrated sample was frozen and thawed three times to break the cells. Then, sodium azide and distilled water was added and the mixture was again centrifuged. Finally, the sample was read in the spectrophotometer (wavelengths 615 and 652 nm) and the phycocyanin concentration was then calculated.