Pink Lake (previously known as Lake Spencer) is a salt lake in the Goldfields-Esperance region of Western Australia.[2] Although historically the water in the lake was visibly pink, as of 2017 it had not been pink for over ten years.[3] Salt concentration is vital to Pink Lake's pink hue, and Pink Lake may turn pink again as conditions change. It lies about 3 kilometres (2 mi) west of Esperance and is bounded to the east by the South Coast Highway.

The dynamics of why a lake turns pink is very complex. External changes and weather conditions can affect the colour of the lake. Esperance's Pink Lake has lost its pink colour due to a number of contributing factors.


Eastern end from Observation Point

Contents
1 Description
2 Name
2.1 Misleading name
2.2 Confusion with Lake Hillier
3 History
3.1 Salt Production
4 The science behind pink lakes
5 Birds
6 References
Description
The distinctive colour of the water changes as a result of green alga Dunaliella salina, halobacterium Halobacteria cutirubrum, and/or high concentration of brine prawn. 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 pink halobacterium grow in the salt crust at the bottom of the lake.[4]

It is believed that the construction of a highway and a rail line altered the flow of water into the lake reducing its salinity which is why (as of 2017) it no longer appears pink.[3]

Name
In 1848 explorer John Septimus Roe named the waterway Lake Spencer after Sir Richard Spencer, a Resident Magistrate in Albany who contributed to the early formation of the colony of Western Australia. Lake Warden, adjacent, is recorded as having been named after Sir Richard Spencer's wife, Lady Ann Warden Spencer.

The Lake has displayed a distinct pink hue in the past and was colloquially referred to as Pink Lake until 1966 when the Shire President, Cr W S Paterson submitted a request to the Geographic Names Committee which was successful and resulted in Lake Spencer officially becoming Pink Lake. For many years Pink Lake was a tourist attraction in the Esperance region with the surrounding area, an arterial road and local businesses adopting the name.

Misleading name
Because tourists who visit Esperance to see the Pink Lake are disappointed not to see a pink lake, there have been proposals to either change the name of the lake and the town back to Lake Spencer or to find a way to alter the salinity so that the lake appears pink once again.[3]

Confusion with Lake Hillier
Lake Hillier is located on Middle Island in the Recherche Archipelago off the coast of Cape Arid, east of Esperance. The Lake is well known for its bright pink hue that contrasts with the deep blue of the ocean. The Island is managed by the West Australian Government and accessible by boat and air.

History
Historically Pink Lake was the terminal lake in the Lake Warden