A video of Lake Maharlu in Iran's Fars Province, located near Shiraz, is widely shared on social media. The lake is attracting attention with its bright pink, and sometimes red, water.

The unusual hue is due to the activity of Dunaliella salina microalgae. During the hot season, when evaporation increases the water's salinity, these organisms begin actively producing astaxanthin, a pigment belonging to the carotenoid group, which gives the water its characteristic color.

The lake's hue changes depending on the season: in spring and autumn, when the water level rises, it takes on a bluish tint, while during dry periods the surface becomes covered with a white salt crust.

Lake Maharlu is one of the largest salt lakes in Iran. It is an important habitat for migratory birds, including flamingos, who are attracted to the same algae that serve as their food source. The lake is protected as a nature reserve.