A cyanobacterial bloom on the Klamath River near Copco, California, swirls around the boat of a sport fisherman, who told the photographer, “Anyone who sees this [photo] is gonna say, ‘That guy’s stupid,’ but they ought to come up and try it. The algae provides a cover for the fish.” However good or bad cyanobacterial blooms may be for fishing, they also produce toxins that can irritate eyes, skin, lungs, and the gastrointestinal tract, and may even cause nerve damage or death at high exposures.7
© David McLain/Aurora Photos/Corbis