A pink lake is a lake that has a red or pink colour due to the presence of algae that produces carotenoids, such as Dunaliella salina.
Examples include Pink Lake,[1] near Esperance, Western Australia; Hutt Lagoon in midwest Western Australia; and Lac Rose in Senegal.
http://www.galenfrysinger.com/senegal_pink_lake.htm http://www.aslo.org/photopost/showphoto.php/photo/814/title/pink-lake/cat/502