Invasive aquatic plant found in Perth waterway

Frogbit on Browns Lake
Frogbit on Browns Lake Credit - DBCA

The Department of Biodiversity, Conservation and Attractions is calling on Perth residents to help manage the spread of Amazon frogbit, following its discovery in a Perth waterway.

Amazon frogbit, a highly invasive aquatic weed that can impact on river health and biodiversity, was first spotted in Bayswater Brook in late December.

Originating from Central and South America, the Amazon frogbit (Limnobium laevigatum) spreads rapidly via fragments that are readily detached from the parent plant. Each plant fragment can produce multiple seed pods with each pod containing 20-30 seeds that are viable for at least three years.

It is sold in Western Australia for use in aquariums, however when disposed of inappropriately the plant has the potential to cause widespread devastation by congesting drains, waterways and wetlands, displacing native vegetation and greatly impacting water quality.

Department of Biodiversity, Conservation and Attractions (DBCA) drainage manager Kate Bushby said prevention, early detection and containment were key to managing the invasive weed as it can double its biomass in a few days.

“The department is working with the City of Bayswater, South East Regional Centre for Urban Landcare and Water Corporation to remove the weed and search for the initial source along the drainage lines of Bayswater Brook,” Ms Bushby said.

“Booms have also been put in place to prevent further movement of the weed down the brook.”

Ms Bushby said the weed may have found its way downstream, and possibly upstream with tidal movement, and could get a foothold in the right conditions.

“We have installed a barrier around the outlet of the basin in Browns Lake Reserve to contain what is currently believed to be the main source of frogbit into Bayswater Brook,” she said.

Since 2013, several infestations of the weed have been recorded across Perth’s eastern and southern suburbs, however they were all found to be isolated incidents.

Anyone who sees this invasive weed should contact the department on 9278 0900 or email This email address is being protected from spambots. You need JavaScript enabled to view it.

For more information on the weed, visit the River Guardians Website at: www.riverguardians.com/news/news-media-releases

Media contact: DBCA Media 9219 9999
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