The New York Daily News reports that the river delta Camargue in southern France (where the Rhone meets the ocean) has turned a shade of deep red.
Responsible for the red water are halophiles: extremophile organisms that thrive in areas with highly concentrated levels of salt.
Halophiles inhabit the Great Salt Lake in Utah, Owens Lake in California, the Dead Sea—not so dead after all—the Camargue and Lake Retba in Senegal. They excrete a photosynthetic red pigment that turns the water.
Fun Fact: salty foods like soy sauce, cod and herring are fermented using halobacteria.