The Department of Primary Industries and Regional Development has issued a warning to gardeners in regional Western Australia after reports were received of illegal water weed salvinia being sold in Margaret RIver, Picton and in the Perth metropolitan area.
Concerns over the sale of the weeds as pond plants have been heightened by sightings of water weeds in a dam and a front garden.
Salvinia was listed for sale online in Margaret River and was reported on a dam in Picton, near Bunbury, while weeds were found in ponds in Bedfordale and Kensington.
The department’s agriculture and food biosecurity officer Glen Coupar said salvinia and other declared water weeds posed a significant threat to the agriculture and food sector as well as the environment.
“Salvinia multiplies very quickly and forms a dense mat that covers lakes, slow-moving rivers, dams and other waterways,” Mr Coupar said.
“The water weed threatens agriculture by blocking irrigation channels and preventing stock from getting access to fresh water from dams, and it deoxygenates water by preventing light and oxygen from entering the water.
“This also impacts native plants and animals in the water and creates an ideal breeding ground for mosquitoes.
“Salvinia is a free-floating weed with distinctive egg-beater like structures at the top of each leaf, which makes it easy to identify.”
Due to the ease and speed with which salvinia spreads, it is not allowed to be sold or moved.
“The frequency of salvinia reports indicates there is some community understanding of the threat the weed poses, but the number of incidences shows we have some way to go in educating everyone,” Mr Coupar said.
Salvinia and other water weeds are easy to identify and report using the MyWeedWatcher mobile device app, developed by the department’s Boosting Biosecurity Defences project.
MyWeedWatcher is available to download free from the App Store and Google Play.
The app’s identification guide allows users to search for a weed according to plant’s characteristics, such as flower colour, leaf shape, and plant type.
The reporting feature enables users to map weeds, add images and record weed density and weed count.
