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 playset.

Photographer Travis Morrin, who captured photos of it, thought the color is more of a “Pepto Bismol pink.”

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

The pink phenomenon at the pond, a natural 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 on site since Oct. 30, and working with the Hawaii Division of Aquatic Resources and state Department of Health to determine a course of action.

Water samples have been sent to the University of Hawaii for analysis, USFWS said.

Based on a preliminary analysis, the Service says the pink color is likely caused by a single-celled organism called halobacteria, which are typically found in high-salinity water bodies.

Kealia Pond near mile post six at Maui Veterans Highway provides habitat for endangered, native waterbirds including the Hawaiian stilt and Hawaiian coot and during winter months, more than 30 species of waterfowl and shorebirds.

USFWS said UH is doing more analysis to determine the exact strain of the halobacteria.

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