Lake Hillier is a lake on Middle Island, the largest of
the islands and islets that make up the Recherche
Archipelago, Western Australia. The
notable feature of the lake is its pink colour. In fact these pink lakes are a
natural phenomenon and not only draw visitors from far and wide but also
provide livelihoods to local people. It is such a significant distinguishing
feature of the archipelago that air passengers often crane their necks to take
a glimpse of it.
Pink lakes tend to have a striking colour due to the
presence of algae that produces carotenoids, such as Dunaliella Salina, a type
of halophile green micro algae especially found in sea salt fields. Once the
lake water reaches a salinity level greater than that of sea water, the
temperature is high enough and adequate light conditions are provided, the alga
begins to accumulate the red pigment beta carotene.
The lake is about 600m long and width is 250m, and is surrounded by a rim of sand and dense woodland of paper bark and eucalyptus trees. Unlike other pink lakes in the world like the one in Retba and the salt ponds at San Francisco Bay, the pink color of Lake Hillier has not been decisively proved, although it is speculated that the color could arise from a dye created by the organisms Dunaliella salina and Halo bacteria. Another hypothesis is that the pink color is due to red halophilic bacteria in the salt crusts. That the color is not a trick of light can be proved by taking water from the lake in a container the pink color can be found to be permanent.
One of the first evidence of Middle Island's pink lake
dates back to the journals of Matthew Flinders, a British navigator and hydrographer
in 1802. He climbed Middle Island's highest peak to survey the surrounding
waters when he came across this remarkable pink lake. Except for a few years
when salt extraction was being carried out here, the island and its pink lake
has been almost untouched and has since then provide visitors with one of the
most amazing view of the world's natural wonder.
Pink lakes tend to have a striking colour due to the
presence of algae that produces carotenoids, such as Dunaliella Salina, a type
of halophile green micro algae especially found in sea salt fields. Once the
lake water reaches a salinity level greater than that of sea water, the
temperature is high enough and adequate light conditions are provided, the alga
begins to accumulate the red pigment beta carotene.
Lake Hillier pictures
