People take photographs of the pink lake at Westgate Park on Wednesday in Melbourne, Australia. A natural phenomenon caused the salt lake to turn pink. /VCG Photo

When salt levels in the lake are higher than usual, the pink color appears. Other factors, like the amount of sunlight and lack of rainfall, reinforce the phenomenon. /VCG Photo

Lake algae that grow in the salt crust at the bottom of the lake produce a red pigment as part of their photosynthesis process under before-mentioned conditions. /VCG Photo

The authorities said the algae do not cause harm to the local wildlife, but warned people not to come into contact with the water. /VCG Photo