In Australia, Lake Hillier has a bright pink hue that can be seen from high up in the air on satellite photos. The lake has a dense concentration of salt, but that isn't the only thing that causes the pink hue. The first half of this video reveals why the lake is so pink. Scientists who researched the phenomenon looked beyond just the salt factor for a more accurate reason. Researchers from the eXtreme Microbiome project went all the way to the cellular composition of the water and sediment in the lake. Taking samples from different areas of the lake, they examined algae, bacteria, and archaea and came up with a thorough metagenomic analysis, drilling down to the DNA of the species that make up the lakes microbiome.
They did find D. Salina, an algae that is present in other pink-toned salty lakes, but it wasn't the only component responsible for the color. A bacteria called dechloromonas aromatica, which is often used to break down solvents like benzene, used in manufacturing. As it happens, the lake was used by a leather tanning factory in the 1900s, and benzene likely contaminated the lake and caused the d. aromatica to form. So while the saltiness of the lake contributed, there is more to the science of this pink lake.