Frogbit (Limnobium laevigatum) has smooth, rounded, fleshy leaves up to 4 cm across. Photo Cardex, Wikipedia
Frogbit. It sounds like a cutesy little amphibian in a waistcoat and who comes out and does a dance with a cane on a lilypad in Rainbow Wishtree Forest. But, Frogbit (Limnobium laevigatum), is far from cutesy, it is an invasive, smothering waterweed that poses a serious environmental threat.
Frogbit has been found in the Richmond River and thanks to a tip-off from a member of the public, at Chinderah.
NSW Department of Primary Industries (DPI) State Priority Weeds coordinator, Charles Mifsud, said the call alerted Rous County Council weeds officers who found frogbit in a Chinderah dam and along 800 metres of an adjacent drainage channel.
Frogbit-(Limnobium-laevigatum) Infestation of frogbit at Green Point, near Forster. Photo Terry Inkson.
‘Further routine investigations identified frogbit in the Richmond River as we continue to work with council weeds officers and North Coast Local Land Services to detect and manage any frogbit infestations.
Frogbit is native to Central and South America and is Prohibited Matter in NSW. It is illegal to have, move or sell this plant in NSW as it poses a serious biosecurity risk.
‘Illegally traded as a pond and aquarium plant, frogbit has spread into our waterways to form large dense mats, prevent native water plants from growing, reduce light, food and shelter for fish and aquatic animals and can block waterways and irrigation channels.’
Frogbit (Limnobium-laevigatum), Frogbit invading a natural waterway near Forster, NSW, Photo Terry Inkson.
The first known incursion of frogbit in NSW waterways was at Green Point in 2017 and infestations have since been detected in the Georges River, Prospect Creek, Fairfield, Smithfield, Greystanes, Canterbury Bankstown, Cessnock, Plumpton, Bulahdelah, Cowra, Forster, Lismore and Camden.
All known infestations of frogbit in NSW have been treated to eradicate the devastating weed.
Mr Mifsud said frogbit has been detected in aquariums and backyard ponds and for sale in aquarium shops, at markets and online.
‘If you suspect a plant in your yard or our waterways or for sale at a market, shop or online is frogbit, please call the NSW DPI Biosecurity Helpline 1800 680 244 or your local council, who can assist in identification and eradication.’ he said.
More information and photographs of frogbit are available on the NSW DPI website. https://weeds.dpi.nsw.gov.au/
