Scientists Discover Reason Behind Vibrant Pink Water at Boondall Wetlands

Scientists have solved the mystery behind why the waters in the Boondall Wetlands turned into a strawberry milkshake hue last November.

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The Water Ecology unit at the Department of Environment and Science (DES) analysed samples sent by Brisbane City Council and identified the microbe responsible, which had not been observed before in south-east Queensland.

“Based on the colour, we originally thought it might be a bacterium that sometimes washes up in mangroves,” said Dr Glenn McGregor, Principal Scientist at DES.

Photo credit: Abhishek Samant/Google Maps

They analysed four samples which confirmed it wasn’t the microbe they thought it was, and they needed to do genetic sequencing to find the pink bloom culprit.

The genetic sequencing done by Dr Chris Rinke at the University of Queensland revealed that the microbe responsible for the pink blooms belongs to the genus Rhodovulum. This type of bacteria had not been seen before in this region by the Department of Environmental Science.

Rhodovulum bacteria are known to thrive in salty coastal areas and environments high in sulphides, like tidal pools and mudflats. They can use sulphides to help them grow and survive.

Due to low rainfall this past winter, the water in Boondall Wetlands became very saline. This created an ideal habitat for Rhodovulum bacteria which need high salinity. As the bacteria multiply rapidly, they turn the water pink through the pigment they produce.

Photo credit: Shamsul Kamal/Google Maps 

Whilst beautiful, pink blooms from Rhodovulum are unusual in Boondall Wetlands. But they can commonly occur along various coastal regions in Australia when conditions allow this bacteria to bloom prolifically.

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About the Boondall Wetlands 

The Brisbane City Council originally acquired the land in the 1960s, initially planning to develop the Boondall Wetlands for construction in the 1970s and 80s. However, strong public opposition led the council to instead establish the area as the Boondall Wetlands Reserve in 1990, creating a protected habitat. This was followed by the opening of the Environment Centre in 1996 to serve as an educational hub for visitors.

Photo credit: Luke H/Google Maps

Spanning approximately 1150 hectares, the Boondall Wetlands consist of a diverse array of habitats along the edge of Moreton Bay. Situated between Nudgee Beach, Boondall and Shorncliffe, the wetlands contain extensive tidal flats, stands of mangroves, saltwater marshes, melaleuca swamps, grassy fields, and open forest. 

Published 2-January-2024