Lake Hillier: A close-up view of the natural wonder

20 January 2016

Located on the edge of Recherché Archipelago’s largest island in Australia, is a natural phenomenon that draws visitors from far and wide. Best known for its striking bubble-gum-pink colour, Lake Hillier is a salt lake located on Middle Island.

Lake Hillier’s most distinguishing feature is its bright pink water colour. It is so striking that airplane passengers passing over Middle Island often get out of their seats just to get a glimpse of it.

No-one fully knows why the lake is pink. The source of the pink colour has not been definitively proven in the case of Lake Hillier (it’s not the only pink lake in the word), however scientists speculate that the colour comes from a dye created by bacteria that lives in the salt crusts. 

The lake is thought to contain a large diversity of halophilic (salt-loving) microorganisms, including algae, bacteria, and archaea. Its striking colour is permanent, and does not alter when the water is taken in a container and despite the high salt content levels (comparable to those of the Dead Sea), Lake Hillier is safe to swim in.

The eXtreme Microbiome Project (XMP)

AGRF is a participant in the eXtreme Microbiome Project (XMP) - a scientific effort to characterize, discover, and develop new pipelines and protocols for extremophiles and novel organisms. It was initiated as part of the Association of Biomolecular Resource Facilities (ABRF) Metagenomics Research Group (MGRG) in 2014 as a consortium of microbiologists, geneticists, oceanographers, and bioinformaticians.

The key goal of the Metagenomic Research Group is to evaluate, study, and refine methodologies related to any aspect of metagenomics and microbiome studies. This includes study designs, controls, detection methods, and bioinformatics pipelines and software. The overall intent of ABRF MGRG is to assist in the advancement of the science of metagenomics with the result of generating more accurate results and standard methods.

Beneath the surface

As part of this study, AGRF travelled to and sampled one of these extreme microbial environments to learn more about the organisms that inhabit the lake. In 2015, Ken McGrath (AGRF Brisbane) undertook a sampling expedition to Lake Hillier, to collect samples from a number of locations including the lakeside bank, the water in the lake, and the lake sediment below the salt crust at the bottom of the lake. Preserved using either dry ice, ethanol, or a DMSO/Salt preservative solution, the samples were returned to AGRF labs for DNA extraction and genetic analysis.

Analysis of the genetic material from the lake shows that the lake is alive with microbial activity. The halophiles (salt-loving organisms) include bacterial, algae, and archaea, and together contribute to the unique and distinct colour that is characteristic of Lake Hillier.

For an up-close view of Lake Hillier, watch the Lake Hillier sampling trip.

Lake Hillier

Lake Hillier’s most distinguishing feature is its bright pink water colour. Its striking colour

is permanent,and does not alter when the water is taken in a container

Lake Hillier

Analysis of the genetic material from the lake shows that the lake is alive with microbial activity. The lake is home to halophiles (salt-loving organisms) such as bacterial, algae, and archaea, and together contribute to the unique and distinct colour that is characteristic of Lake Hillier.

Lake Hillier

Samples were collected from a number of locations including the lakeside bank, the water in the lake, and the lake sediment below the salt crust at the bottom of the lake.