From up above, the water at Kealia Pond National Wildlife Refuge in South Maui appears to be bright pink — as pink as bubble gum or a Barbie play set.

Photographer Travis Morrin, who captured aerial views of it, thought of it more as “Pepto Bismol pink.”

“I was shocked,” said Morrin, a Maui chef and restaurateur who takes photos as a hobby. “It was like this Pepto Bismol-­Barbie pink, vibrant color.”

Morrin, co-owner of Fork &Salad and Three’s Bar &Grill, said he visits the pond every so often to take photos and enjoy the serene setting, but has never seen it turn pink.

The pink phenomenon at the pond, a wetland and bird sanctuary run by the U.S. Fish and Wildlife Serv­ice, is drawing attention from around the world.

USFWS says its staff has been monitoring the pink water since Oct. 30, and working with the Hawaii Division of Aquatic Resources and state Department of Health to determine a course of action.

Additionally, water samples have been sent to the University of Hawaii for analysis.

Based on a preliminary analysis, the service says the pinkness is likely caused by single-celled organisms called halobacteria, typically found in high- salinity water bodies.

The salinity in the pond outlet is currently greater than 70 parts per thousand, or twice the salinity of seawater, USFWS said, providing favorable conditions for halobacteria.

The pinkness is not likely caused by the toxic algae that produces red tides, the service said.

Morgan Wittmer, ecotour manager for the Pacific Whale Foundation, said she also believes the pinkness is due to salt-loving halobacteria, which is a naturally occurring bacteria.

“It’s a result of dry conditions and warm temperatures,” she said, “and it’s a bacteria that loves salt. Under dry conditions, that pond water dries up.”

Without rainfall or any additional flow of water into the pond, the result is evaporation and higher salt concentration. She said it’s anyone’s guess how long this will last, and that it depends on whether rain will help dilute the salt.

The island of Maui is currently in severe to extreme drought, according to the U.S. Drought Monitor, with the swath where the pond is located in the latter category.

On Wednesday, Wittmer observed birds feeding in the pond and said there were no signs of dead fish.

“This is a phenomenon that happens around the world,” she said. “It’s not completely rare, but it’s unusual.”

An online search yielded images of the pink phenomenon occurring in other water bodies, including wetlands the color of “strawberry milk” in eastern Australia, a pink pond in the British Virgin Islands, and another pink pond in Santa Clara, Calif.

Kealia Pond near mile post six at Maui Veterans Highway provides habitat for endangered native waterbirds including the Hawaiian stilt, Hawaiian coot and black-crowned night heron. During winter months, more than 30 species of waterfowl, shorebirds and migratory ducks can be seen visiting the refuge.

Wittmer said it’s fitting the pond is pink, representing Maui’s color and official flower, the lokelani.

“I think it’s part of our everyday rainbow,” she said. “Maui’s so beautiful. We’re adding to the rainbow.”

USFWS said UH is doing more analyses to determine the exact strain of the halobacteria at the pond.

“We will be continuing to gather information and will keep the public informed,” said USFWS. “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.”