Pink Lake (previously known as Lake Spencer) is a

salt lake A salt lake or saline lake is a landlocked body of water that has a concentration of salts (typically sodium chloride) and other dissolved minerals significantly higher than most lakes (often defined as at least three grams of salt per litre). ...

in the Goldfields-Esperance region of

Western Australia Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to th ...

. Although historically the water in the lake was visibly pink, as of 2017 it had not been pink for over ten years. Salt concentration is vital to Pink Lake's pink hue, and Pink Lake may turn pink again as conditions change. It lies about west of Esperance and is bounded to the east by the

South Coast Highway South Coast Highway is a Western Australian highway. It is a part of the Highway 1 network. With a length of , it runs from Esperance to Walpole roughly in parallel to Western Australia's south coast. Even then the journey is pretty much in ...

. The dynamics of why a lake turns pink are 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 salinity changes caused by human activity. Pinklake1

Description

The distinctive colour of the water changes is a result of green alga ''

Dunaliella salina ''Dunaliella salina'' is a type of halophile green unicellular micro-algae especially found in hypersaline environments, such as salt lakes and salt evaporation ponds. Known for its antioxidant activity because of its ability to create large a ...

'',

halobacterium ''Halobacterium'' (common abbreviation ''Hbt.'') is a genus in the family Halobacteriaceae. The genus ''Halobacterium'' ("salt" or "ocean bacterium") consists of several species of Archaea with an aerobic metabolism which requires an environment ...

Halobacterium cutirubrum ''Halobacterium salinarum'', formerly known as ''Halobacterium cutirubrum'' or ''Halobacterium halobium'', is an extremely halophile, halophilic ocean, marine obligate aerobic archaeon. Despite its name, this is not a bacteria, bacterium, but a mem ...

'', and/or high concentration of brine

prawn Prawn is a common name for small aquatic crustaceans with an exoskeleton and ten legs (which is a member of the order decapoda), some of which can be eaten. The term "prawn"Mortenson, Philip B (2010''This is not a weasel: a close look at nature ...

. Once the lake water reaches a

salinity Salinity () is the saltiness or amount of salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensionless and equal ...

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 Beta (, ; uppercase , lowercase , or cursive Greek, cursive ; grc, βῆτα, bē̂ta or ell, βήτα, víta) is the second letter of the Greek alphabet. In the system of Greek numerals, it has a value of 2. In Modern Greek, it represents th ...

. The pink

grow in the salt crust at the bottom of the lake. It is believed that the construction of the South Coast 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.

Name

In 1848 explorer

John Septimus Roe John Septimus Roe (8 May 1797 – 28 May 1878) was the first Surveyor-General of Western Australia. He was a renowned explorer, a member of Western Australia's legislative and executive councils for nearly 40 years, but also a participant in t ...

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.

Confusion with Lake Hillier

Lake Hillier 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 in the Goldfields-Esperance region, off the south coast of Western Australia. It is particularly notable ...

is located on Middle Island in the

Recherche Archipelago The Archipelago of the Recherche, known locally as the Bay of Isles, is a group of 105 islands, and over 1200 "obstacles to shipping", off the south coast of Western Australia. The islands stretch from east to west and to off-shore encomp ...

off the coast of

Cape Arid Cape Arid National Park is a national park located in Western Australia, southeast of Perth. The park is situated east of Esperance and lies on the shore of the south coast from the eastern end of the Recherche Archipelago. The bay at its east ...

, 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 Western Australian Government and is accessible by boat and air.

History

Historically Pink Lake was the terminal lake in the Lake Warden wetland system, where water from the central suite of lakes (Wheatfield, Woody and Windabout) and Lake Warden would periodically flush into Pink Lake, bringing accumulated salts into the environment. Increasing salt concentrations combined with decreasing water levels from evaporation during summer trigger the appearance of the pink hue that can be seen in lakes across the country. Pink Lake lost its connection to Lake Warden and the eastern lakes with the construction of the railway line and South Coast Highway. Commercial salt mining, which began in 1896 and ceased in 2007 reduced salt levels in the lake. Further reductions to the lake's salt concentration was caused by freshwater entering the system, through a combination of surface water inflow and increased groundwater inflow due to clearing in the catchment area associated with nearby subdivisions.

Salt Production

Prior to salt production the lake's environment was investigated in the 1980s.

Table salt Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in the form of a natural crystalline mineral is known as rock salt or halite. Salt is present in vast quantitie ...

is produced in

solar pond A solar pond is a pool of saltwater which collects and stores solar thermal energy. The saltwater naturally forms a vertical salinity gradient also known as a "halocline", in which low-salinity water floats on top of high-salinity water. The ...

s at the eastern end of the lake. The company WA Salt Supply produce water softening salt, coarse salt and sheepskin salt at the Esperance site. The salt is

kiln A kiln is a thermally insulated chamber, a type of oven, that produces temperatures sufficient to complete some process, such as hardening, drying, or chemical changes. Kilns have been used for millennia to turn objects made from clay int ...

dried, crushed and bagged at the site before being distributed.

Birds

The lake has been identified by

BirdLife International BirdLife International is a global partnership of non-governmental organizations that strives to conserve birds and their habitats. BirdLife International's priorities include preventing extinction of bird species, identifying and safeguarding ...

as an

Important Bird Area An Important Bird and Biodiversity Area (IBA) is an area identified using an internationally agreed set of criteria as being globally important for the conservation of bird populations. IBA was developed and sites are identified by BirdLife Int ...

because it usually supports significant numbers of

hooded plover The hooded dotterel or hooded plover (''Thinornis cucullatus'') is a species of bird in the family Charadriidae. It is endemic to southern Australia, where it inhabits ocean beaches and subcoastal lagoons. There are two recognised subspecies whic ...

s and sometimes over 1% of the world population of

banded stilt The banded stilt (''Cladorhynchus leucocephalus'') is a nomadic wader of the stilt and avocet family, Recurvirostridae, native to Australia. It belongs to the monotypic genus ''Cladorhynchus''. It gets its name from the red-brown breast band fo ...

s. It has had many migrant and native birds. Between 1997 and 2006, populations ranging between 12 and 12,000 of the banded stilt were recorded. There was a population of between 5 and 68 of the hooded plovers from 1995 to 2005.

References

{{portalbar, Lakes Lakes of Goldfields-Esperance (Western Australia) Saline lakes of Western Australia Important Bird Areas of Western Australia