Lookout for sale of illegal water weeds

The declared water weed salvinia is a significant threat to the agriculture and food sector as it can block irrigation channels.

GINGIN and Yanchep gardeners are asked to keep a lookout for the sale of illegal water weeds after salvinia was reported being sold at weekend markets and online in recent weeks.

Reports received by the Department of Primary Industries and Regional Development of illegal weeds being sold as pond plants have been heightened by sightings of water weeds in a dam and a front garden – signifying the need for a community reminder.

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,” he 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 department received several reports of salvinia being sold at Morley weekend market, a report of the weed in a pond in suburban Kensington, and in a large pond in the semi-rural suburb of Bedfordale.

Salvinia was also listed for sale online in Margaret River and it has been reported on a dam in Picton, near Bunbury.

“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.’’

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.

People who don’t have a mobile device can report weeds or sales of suspect weeds using MyWeedWatcher online, or by contacting the pest and disease information services by emailing info@agric.wa.gov.au or free call 1800 084 881.