

Pink Lake is regarded as a local phenomena in Western Australia - at certain times of the year the left side of the lake is a distinctive pink color. Summer evaporation causes the water level to drop and salt builds up. When the water returns, the salt causes the pink color.
(Source: viage, via thesleepless-sunday)
Sounds like there might be some sneaky little halophiles living in that there lake hence the pink colour. :)