Fascinated visitors have been flocking to the ‘pink’ pond after images of the strange spectacle started appearing on social media.

Volunteers from the Kealia Pond National Wildlife Refuge on Maui, many of whom have been around the water for 70 years, say they have never seen anything like this before.

Refuge Manager, Bret Wolfe, said he was first aware of the strange occurrence when a beach walker said to him: “There’s something weird going on over here”.

Although the pond might look glorious with its magenta hue, officials are concerned about the cause. Kealia Pond National Wildlife Refuge is one of the few coastal salt marshes on the island of Maui and during an extreme drought, its salt content levels surged.

Water samples sent to the University of Hawaii suggest that halobacteria is the reason for the pond’s colour. Halobacteria are single-celled organisms that thrive in very salty water, like the Great Salt Lake and the Dead Sea. The bacterium is known as an extremophile because it can live in such an extreme environment – in this case one where the water salinity is twice that of seawater.

However, Mr Wolfe said the pond has previously been through periods of drought and high salinity and it remains a mystery as to why the colour has changed this time.

DNA analysis is being carried out to confirm the source of the pond’s colour transformation and visitors are being warned not to enter the water or eat any fish caught there while the cause is still being investigated.