Lake Hillier, on Middle Island off the south coast of Western Australia, is an iconic lake celebrated for its vivid pink color. Nestled in the pristine wilderness of the Recherche Archipelago, algae and bacteria interact with the saline water to cause the lake’s distinctive pink shade.

More specifically, scientists postulate that the lake’s solid bubblegum color results from the intermixing of Halobacteria and a salt-tolerant algae species called Dunaliella Salina.

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When mixed with salt-tolerant microalgae, the bacteria produce red pigments that create a stunning strawberry milkshake color. The chemical reactions between salt and microorganisms make the lake ten times saltier than the Southern Ocean nearby.

Why Lake Hillier is Pink, a summary

• Presence of Specific Algae and Bacteria: Microorganisms such as Dunaliella salina contribute to the pink coloration.
• High Salt Content: The saline water in Lake Hillier interacts with the organisms (no, not the giant pink slug), enhancing the pink hue.
• Production of Carotenoids: These microorganisms produce red pigments called carotenoids, adding to the lake’s distinctive color.
• Natural Interaction: The combination of these factors and environmental conditions results in the captivating pink shade that distinguishes Lake Hillier.

The lake is also still safe to swim in but that doesn’t mean you should do it.

Can You Swim in Lake Hillier?

The alluring pink hue of Lake Hillier might tempt many to dive in, but authorities generally do not allow swimming in the lake. Helicopter tours primarily provide access to the area, and they usually restrict visitors from entering the water. This restriction preserves the delicate ecosystem that creates the lake’s distinctive color. However, tourists can still marvel at this unique natural wonder without disturbing its beauty and balance by viewing Lake Hillier from the shore or during a scenic flight.

There are 29 other pink lakes in the world. But unlike other pink lakes that morph into different colors, Lake Hillier — 2,000 feet long and 660 feet wide — retains its pink hue all year round. The contrast between the bright pink and dark blue ocean water is stunning.

List of worldwide pink lakes

Name	Location
Lake Hillier	Western Australia
Salina de Torrevieja	Spain
Lake Retba	Senegal
Hutt Lagoon	Western Australia
Dusty Rose Lake	Canada
Pink Lake	Victoria, Australia
Salinas de San Pedro del Pinatar	Spain

This post was originally published on January 2, 2022, and updated on August 24, 2023.