A pond in Hawaii turned pink, prompting a red environmental flag

A pond in Hawaii became a social media spectacle this week after turning bubble gum pink. However, experts said the new hue was not just a photo opportunity, but an indicator of environmental stress.

Staff at the Kealia Pond National Wildlife Refuge on Maui have been monitoring the pink water for the past two weeks, according to the U.S. Fish and Game Serviceafter initial fears that the color was the result of toxic algae.

Instead, tests showed that the source of the pink hue was likely halobacteria, a type of archaea, or single-celled organism that thrives in water bodies with high salinity, the agency said.

Salinity in the Kealia Pond outlet area is currently greater than 70 parts per thousand, which is twice the salinity of seawater.

Combined with the dry conditions resulting from Maui’s drought, which is rated “severe” in most of the county, the pond’s salinity created the perfect conditions for the halobacteria to thrive.

The University of Hawaii is conducting further tests to learn more about the archaea.

The water is unlikely to pose a threat to public health, said Dr. Shiladitya DasSarma, a professor in the department of microbiology and immunology at the University of Maryland School of Medicine.

The microorganisms would not be able to survive in the human body because the body does not have enough salt for the halobacteria to survive, said Dr. DasSarma.

Still, officials have advised visitors to stay out of the water to avoid consuming fish from the pond and to ensure pets don’t drink from it either.

The bright pink hue still causes concern in the surrounding ecosystem.

The color indicates that the salinity of the water is too high for most fish to survive or for other animals to drink, he said.

“It’s basically a flashing red light that the ecology of this area is under serious threat,” said Dr. DasSarma.

Often, bodies of water have turned red before drying up, he said, although it is unclear whether that would be the case for Kealia Pond. Employees of the nature reserve told us The Associated Press that rainfall could reduce salinity and possibly change the color of the water.

Such color changes are not unheard of in the United States, said Dr. DasSarma.

Portion of the Great Salt Lake in Utahfor example, has been pink since the 1950s, according to the Great Salt Lake Collaborationafter part of it split off from the rest and developed a higher salinity.

Other pink or red lakes exist around the world due to their high salinity, including in places such as Spain, Senegalthe Crimean peninsula, Azerbaijan and others elsewhere.

Normally, such color changes would occur in much drier places.

The latest episode in Hawaii, which is usually the case some moisturetalks about more extreme weather events due to climate change, said Dr. DasSarma.

“This is seen more often around the world, but you don’t think about Hawaii; it’s not an arid part of the world,” he said.