There’s something truly calming about spending time near a pond or river—the gentle sound of water flowing, the sight of greenery reflecting on the surface, and the peaceful atmosphere all combine to create a perfect spot for relaxation and reflection.
But you might be surprised to learn that some of these innocent-looking plants are causing havoc in our waterways—and could land you a hefty fine.
A recent discovery in northern New South Wales (NSW) has put the spotlight on a silent invader: frogbit, a fast-growing aquatic plant that’s now choking an important river near Banora Point.
Local authorities are sounding the alarm, warning residents that improper disposal of this ‘prohibited plant’ damages the environment and could cost you up to $2,000 in fines.
Frogbit (Limnobium laevigatum) might look harmless, with its small, floating leaves and delicate appearance, but don’t be fooled.
Native to Central and South America, this plant is a master of disguise—and destruction. It forms dense mats on the surface of freshwater systems, blocking sunlight and oxygen from reaching native aquatic plants and animals.
Over time, these thick mats can clog waterways, stormwater drains, and irrigation channels, leading to flooding, loss of biodiversity, and costly clean-ups.
The recent infestation near Banora Point is believed to have started when someone dumped unwanted frogbit into a local waterway.
While it’s easy to think that tossing a few plants into a creek or dam is harmless, the reality is far more sinister.
Once established, frogbit spreads rapidly, hitching a ride on the natural flow of water and quickly colonising new areas.
Here’s where things get tricky. While frogbit is still sold legally in some parts of Australia, like Queensland, just a stone’s throw from the NSW border, it’s strictly prohibited in New South Wales, South Australia, Western Australia, the Australian Capital Territory, Northern Territory, and Tasmania.
Under the Biosecurity Act 2015, buying, selling, trading, or moving frogbit into these states is illegal. If caught, you could face an on-the-spot fine of $2,000.
A spokesperson from Rous County Council, which manages the Northern Rivers region’s water supply and weed biosecurity, explained: ‘We understand that NSW residents may have purchased frogbit not realising it is classified as prohibited matter. If you have frogbit, please notify the Rous Weed Biosecurity Team, who will dispose of it properly for you.’
The main culprit behind the spread is the illegal dumping of aquarium or pond plants. It’s a classic case of good intentions gone wrong—someone cleans out their fish tank or garden pond and, not wanting to throw the plants in the bin, tips them into a nearby creek or dam.
Authorities acted quickly when the latest infestation was discovered, with Weed Biosecurity Officers moving to contain the outbreak.
But the incident is a stark reminder: never dispose of household plants in waterways, creeks, dams, wetlands, or stormwater drains.
Frogbit isn’t officially prohibited if you’re in Queensland or Victoria, but that doesn’t mean you’re off the hook.
The Queensland government reminds all residents that they have a ‘general biosecurity obligation’ to take reasonable and practical steps to minimise the risks posed by invasive species. In other words, just because you can buy it, doesn’t mean you should let it loose.
The Invasive Species Council has called for a nationwide ban on high-risk weeds like frogbit, English Ivy, and gazanias, warning that inconsistent state rules make it too easy for these plants to slip through the cracks.
If you’ve got frogbit in your pond or aquarium and live in a state where it’s prohibited, don’t panic—but don’t ignore it, either.
Contact your local weed biosecurity team (like the Rous Weed Biosecurity Team in northern NSW) and arrange for safe disposal. Never dump it in the bin, compost, or any natural waterway.
Have you ever spotted frogbit or another invasive plant in your local area? Should there be a national ban on high-risk weeds? Or perhaps you’ve got tips for responsible plant disposal? Share your thoughts in the comments below!
Also read: Is a deadly threat hiding in your backyard? Victorians urged to watch out before it’s too late
