The invasive plant, regarded as one of the most damaging aquatic weeds in Australia, had spread several metres across a semi-rural drain, when it was found and treated by the Water Corporation.
Department of Primary Industries and Regional Development (DPIRD) regional biosecurity coordinator Tim Stevens said the fast-growing plant was a Weed of National Significance and proliferated during the warmer seasons.
“Salvinia forms dense mats that smother the surface of the water,” Mr Stevens said.
“It can devastate our waterways and cause great environmental damage. It can also damage our agricultural and tourism economies.
“Salvinia chokes irrigation channels, blocks irrigation structures, pollutes drinking water and displaces native birds, plants and animals. Its growth can also prevent recreational activities such as swimming, fishing and boating.
“It is great to see a prompt response by the Water Corporation, which reported the weed to DPIRD.”
The weed has been sprayed and the remainder will be removed by hand. The area will be monitored to ensure there is no further spread.
“It is a timely reminder that if people see any unusual plants in a water way, particularly if it is spreading, causing a blockage or congestion, to make a report using the MyPestGuide Reporter app or contact the department,” Mr Stevens said.
Salvinia is a free-floating aquatic fern with slender stems, floating leaves and a root-like structure. The leaves, which float on the water surface, are paired and round-to-oval in shape, with dense, waxy hairs on the upper surface.
“We also remind people not to empty any aquariums or fishponds into water systems, as they could affect our native aquatic life and fish can spread disease and impact native fish stocks,” Mr Stevens said.
Water Corporation senior environment advisor Sue Stain said a drainage monitoring program had uncovered several invasive vegetation species in recent years.
“We work closely with DPIRD and other agencies to proactively identify and control weeds which, if left unaddressed, could have serious environmental impacts,” Ms Stain said.
“This includes invasive species like Amazon frogbit, water hyacinth and the kidney leaf mud plantain, which in the past four years we’ve been able to identify, contain and manage.
“A healthy drainage network supports healthy waterways generally, so it’s really pleasing to see this important work having a positive impact.”
Any suspected sightings of salvinia or other aquatic weeds can be made via the department’s MyPestGuide Reporter app® via the Apple Store or Google Play or by contacting the Pest and Disease Information service on 9368 3080 or mailto:padis@dpird.wa.gov.au.
