NASA Earth Observatory

Algae is turning this Iranian lake from dark green to blood red

For years, Iran’s Lake Urmia has been vanishing, thanks to droughts, rising temperatures, and poor water management. Now, NASA’s Aqua satellite has fingered another source of the saltwater lake’s woes: algae and bacterial blooms. National Geographic reports that recent satellite images of the lake have shown it turning from a dark green color to a dark red, indicative of a microalgae called Dunaliella salina. As the lake reduces in size, it also grows saltier, making it a great breeding ground for the algae, which turns the water blood-red. Usually, rain and melting snow in the spring return freshwater to Lake Urmia, stabilizing the salinity. But as a drought and agricultural use continues in the region, it is likely that such algal blooms may become more common.