A significant infestation of the highly invasive aquatic weed, Water lettuce (Pistia stratiotes), has been discovered at Piggabeen in the Tweed Shire, raising concerns about the spread of this prohibited species through backyard ponds and unregulated plant sales.
The outbreak, identified by the Rous County Council (Rous) Weed Biosecurity team, covers approximately 400 metres of waterway and has spread from billabongs onto the roadside, impacting three private properties.
Surveillance of downstream areas is now underway to determine if the weed has spread further.
Water lettuce is a targeted priority weed in the North Coast region of New South Wales (NSW) due to its rapid growth and potential to severely damage aquatic ecosystems.
Rous is actively working to eradicate this weed from the region, given its potential to form dense surface mats that block sunlight, deplete oxygen levels, and outcompete native aquatic plants and animals.
Water lettuce is often unintentionally spread when shared or sold as an ornamental plant for backyard ponds, according to Phil Courtney, Rous Weed Biosecurity Manager.
“Buying or sharing plants through informal channels, especially online or across the border in Queensland, can result in people unknowingly introducing prohibited species into New South Wales,” said Mr Courtney.
“Even well-meaning actions like sharing plants with neighbours can result in serious environmental consequences and penalties.”
Mr Courtney urged local residents to be vigilant and to understand their General Biosecurity Duty under NSW law. Under NSW biosecurity regulations, it is illegal to buy, sell, grow, or release this species.
“Biosecurity laws can vary between states, so it’s essential to check what’s legal where you live. We’re asking all landholders to make sure they’re only buying plants from licensed sellers.”
“We need to keep Water lettuce out of our waterways because of how aggressively it spreads.
“Seeds from just one plant can start a major infestation. Early detection and prompt action are our best defences,” he said.
Anyone who suspects they have seen Water lettuce is urged to contact Rous on 6623 3800.
