A Hawaiian pond turned bubblegum pink this week and became a social media spectacle. But experts said the new hue was more than just a photo opportunity, it was an indicator of environmental stress.
Officials at Maui’s Kealia Pond National Wildlife Refuge have been monitoring the pink water for the past two weeks, initially fearing the color was caused by toxic algae, the U.S. Fish and Wildlife Service said. That’s what it means.
Instead, tests showed that the cause of the pink hue was likely halophiles, a type of archaea that thrives in waters with high salt concentrations, or single-celled organisms, the agency said.
The salinity within the outlet area of Kearia Pond is currently over 70 percent, which is twice the salinity of seawater.
The pond’s salinity, combined with Maui’s drought-induced dry conditions (rated as “severe” in much of the county), created the perfect conditions for halophilic bacteria to thrive.
The University of Hawaii is conducting further experiments to learn more about archaea.
Dr. Shiladitya Dassarma, professor of microbiology and immunology at the University of Maryland School of Medicine, said if the microbes are halophiles, the water is unlikely to pose a public health threat.
Dr. Dassarma said the microorganism would not be able to survive in the human body because there is not enough salt in the body for the halophilic bacteria to survive.
Still, authorities advise visitors not to go into the water, not to eat fish in the pond, and to prevent pets from drinking the pond water.
The bright pink color still causes concern for the surrounding ecosystem.
The color indicates that the water is too salty for most fish to survive or for other animals to drink, he said.
“Basically, it’s like a flashing red light that the ecosystem in this region is severely damaged,” Dr. Dassarma said.
He said bodies of water often turn red before drying up, but it’s unclear whether that’s the case with Kealia Pond. Wildlife sanctuary staff told The Associated Press that rainfall could reduce salinity and change the color of the water.
Dr. Dassarma said such color changes are not unheard of in the United States.
For example, parts of Utah’s Great Salt Lake have been pink since the 1950s because parts of it were separated from the rest and became more salty, according to the Great Salt Lake Cooperative.
Lakes around the world are pink or red due to high salinity, including Spain, Senegal, Crimea, and Azerbaijan.
Such color changes usually occur in drier locations.
Dr. Dassarma said the incident in Hawaii, which usually has some humidity, speaks to more extreme weather events caused by climate change.
“This is more common around the world, but you can’t think of Hawaii. Hawaii is not an arid region of the world,” he says.