Lake Hillier is a saline lake on the edge of Middle Island, the largest of the islands and islets that make up the Recherche Archipelago off the south coast of Western Australia. It is particularly notable for its pink colour. A long and thin shore divides the Southern Ocean from the lake.
Lake Hillier is about 600 metres (2,000 ft) in length by about 250 metres (820 ft) in width. The lake is surrounded by a rim of sand and a dense woodland of paperbark and eucalyptus trees with a narrow strip of sand dunes covered by vegetation separating its northern edge from the northern coast of Middle Island. The most notable feature of the lake is its pink colour. The vibrant colour is permanent, and does not alter when the water is taken in a container. The source of the pink colour is considered to be due to the presence of the organism Dunaliella salina. Air is the best mode of transportation for viewing the lake.
Forms of Life:
The only living organism in Lake Hillier is Dunaliella salina, the microorganism that causes the salt content in the lake to create a red dye, hence the colour. Another hypothesis is that the pink colour is due to red halophilic bacteria in the salt crusts. Despite the unusual hue, the lake exhibits no known adverse effects upon humans. From above, the lake appears a solid bubble gum pink, but from the shoreline it appears more of a clear pink hue. The shoreline is also covered in salt crust deposits.
Safety and Accessibility:
Despite the high salt content levels (comparable to those of the Dead Sea), Lake Hillier is safe to swim in. However, there are very few ways to reach Lake Hillier. Helicopter is one of the most common methods of travel. Cruises are also an option for passengers wanting to visit the isolated lake, and surrounding forest area.
Protected Area Status:
As recently as 2012, Lake Hillier has been located within the boundaries of the Recherche Archipelago Nature Reserve. Since 2002, the lake itself has been considered to be a wetland of “subregional significance”.