water stream over rocks


WRRC Investigates Pink Maui PondNovember 2023

WRRC Investigates Pink Maui PondNovember 2023

Keālia Pond National Wildlife Refuge.

On October 30, the U.S. Fish and Wildlife Service, which manages the Keālia Pond National Wildlife Refuge, discovered that the pond had turned pink. The Clean Water Branch of the Hawaiʻi State Department of Health (DOH) sent samples of the pink water from the refuge to UH Mānoa’s Water Resources Research Center (WRRC) for further analysis. 

WRRC Associate Researcher Marek Kirs and School of Life Sciences Professor Stuart Donachie are leading UH’s research effort on the pond. Their preliminary results suggest that the change in water color is due to the growth of halophilic prokaryotes, thriving in the pond’s salty conditions, not algae. 

According to Kirs, “No groups of algae known to be associated with the production of phycotoxins were observed in the sample.”

The U.S. Fish and Wildlife Service website states that the salinity in the pond outlet is currently greater than 70 parts per thousand - twice the salinity of seawater. 

Kirs and Donachie are currently in the process of isolating and identifying the strain of halophilic prokaryotes that are present and are awaiting further results. 

Cultures of microorganisms found in the Keālia Pond National Wildlife Refuge. (Courtesy of Marek Kirs).


UH News (November 14, 2023) https://www.hawaii.edu/news/2023/11/14/pink-maui-water-likely-caused-by-bacteria/

CNN (November 10, 2023) https://www.cnn.com/2023/11/10/climate/pink-kealia-pond-hawaii/index.html