Why was Maui pond’s water pink? Possibilities explored as federal wildlife officials warn onlookers to keep distance

A Maui pond in Hawaii has turned bright pink since late October, and scientists think it could be a result of copious amounts of “halobacteria” in the water, along with high salt levels due to drought.

Halobacteria are organisms that live and expand in conditions deemed too extreme for most living beings, such as water bodies with extremely high salt levels. As such, they are called "extremophiles." The Halobacteria are single-celled organisms, as per The Guardian.

The Maui pond is a part of the Hawaiian Wildlife Refuge. As word got around of the water body's bubblegum pink hue, many visitors started going to the place to catch a glimpse of the odd phenomenon. However, staff at the Kealia Pond National Wildlife Refuge in Maui have asked the locals to practice caution.

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Maui pond turns pink due to possible halobacteria

On October 30, 2023, the US Fish & Wildlife Service began monitoring the Maui pond's sudden change of color. To determine the cause of the bright pink pond water and find a course of action, they have partnered up with the Hawaii State Department of Aquatic Resources and the Department of Health for the project.

Bret Wolfe, the Kealia Pond National Wildlife Refuge manager, said:

"I just got a report from somebody that was walking on the beach, and they called me up like, "There’s something weird going on over here.'"

Wolfe was worried that the rosy hue of the Maui pond was a sign of an algae bloom. The toxic algae can produce harmful red tides in the water bodies.

However, a preliminary analysis of water samples by the University of Hawaii (UH) showed that the water’s pink color was “not likely a toxic algae”, as per USA Today.

The US Fish & Wildlife Service has still asked the locals and tourists to avoid contact with the Maui pond until more analysis is done. They said:

"As a precautionary measure, we recommend that people keep a safe distance and not enter the water, don’t consume any fish from the water, and ensure that pets don’t drink the water."

As per The New York Post, the recent drought in Maui may have contributed to the unusual transformation. The scientists at the Hawaiian Wildlife Refuge believe that the pink color was caused by “halobacteria” which thrive on water bodies that have high salt levels.

According to the tests, Wildlife officials have determined that the current salinity levels of the Maui pond are greater than 70 parts per thousand. The levels are two times as high as those found in seawater.

The saline has created favorable conditions for the bacteria, as per The Guardian. However, to definitely identify the organism, the lab will need to conduct DNA analysis, according to Bret Wolfe.

The US Fish & Wildlife Service has noted that they would keep the public informed about any updates on the analysis while the University of Hawaii keeps working to determine the exact strain of the halobacteria.

The Kealia Pond National Wildlife Refuge's typical freshwater pond measures up to about 400 acres when the climate is the rainy winter season and shrinks down to about half its surface area during the spring and summer months. The refuge is a coastal salt marsh that is close to Maui’s south-central coast.

In 1953, Kealia Pond became a part of the wildlife refuge and it was entered into the National Wildlife Refuge System in 1992, as per USA Today.