Many canyons in Zion are closed because of cyanobacteria. An educated guess would say that the cyanobacteria outbreak goes beyond the park borders. It's just monitored in the National Park. It seems that people are doing canyons outside the park to avoid it, but it also seems like other canyons in the vicinity might have it (Misery, Parunaweap, Deep Creek, Kanarra Creek, Benson Creek, Kolob near the MIA [unless it's dry], Ashdown Gorge, etc. Looking at photos of it, it just looks like algae. How do you recognize it? What are you supposed to do if you see some in a canyon? I mean besides trying to keep your head out of the water.