Mystery Boondall Wetlands pink bloom microbe identified
Issued: 13 Nov 2023
Conditions were right to turn the Boondall Wetlands water pink.
Scientists have solved the mystery of the pink blooms that left the water in the Boondall Wetlands resembling a strawberry milkshake.
And the Water Ecology unit at the Department of Environment and Science (DES) identified that the microbe responsible for the pink colouration has not been observed by DES scientists previously in south-east Queensland.
Principal Scientist Dr Glenn McGregor said he received water samples for analysis from the Brisbane City Council in early October.
“Based on the colour of the water, we originally thought it might be a bacterium that sometimes washes up in mangroves and can cause similar pinkish accumulations,” Dr McGregor said.
“We analysed four samples which confirmed it wasn’t the microbe we thought it was, and we needed to do genetic sequencing the find the pink bloom culprit.
“The genetic sequencing was completed by Dr Chris Rinke at the University of Queensland.
“The sequencing results have shown the microbe belongs to the genus Rhodovulum, and this is the first time this bacterium has been observed by DES in south-east Queensland before.
“Rhodovulum is associated with pink coastal waters and sulfide-rich environments such as blooming seawater pools and mudflats.
“These bacteria utilize sulfide as an electron donor for growth which helps them survive in these in sulfide-rich environments.
“Due to the lack of winter rain, the Boondall Wetlands became saline, which created the perfect environment for Rhodovulum microbes that require hyper-saline conditions.
“As the Rhodovulum microbes reproduce and the populations booms, they turn the water pink because of their colouration.
“The beautiful pink blooms at the Boondall Wetlands is rare, but there are plenty of coastal locations across Australia with pink water when conditions are right.”