Skip to main content
. Author manuscript; available in PMC: 2016 Mar 1.
Published in final edited form as: Harmful Algae. 2015 Dec;49:63–74. doi: 10.1016/j.hal.2014.10.002

Fig. 2.

Fig. 2

Alert levels for toxic cyanobacteria in recreational waters compared internationally on basis of microcystins (top panel), cell numbers (middle panel) and biovolume of cyanobacteria (lower panel). White means Surveillance mode, black Alert mode and hatched Action mode. See text for details. The upper end of the scale is “open”, meaning that for instance any level of microcystin exceeding the upper boundary of Alert mode automatically falls into Action mode, but concentrations (in particular in scums) clearly can be higher than the maximum value of 150 μg L 1 on the y-axis of the top panel a (analogous for middle and lower panels).