Port Hedland residents who may have unwittingly acquired a declared aquatic weed via a social media transaction have been asked to contact the Department of Primary Industries and Regional Development.
Water lettuce (Pistia stratoites), also known as water cabbage, was recently traded online in the Pilbara town to a number of purchasers.
The department is now investigating trace back and forward movements of the weed to prevent it from becoming established in the region.
Biosecurity officer Lara Martin said water lettuce was a declared weed in Western Australia, which means it is prohibited from being sold and must be destroyed.
Ms Martin said the department had removed the weed from the vendor’s property but needed the public’s help to trace where the other water lettuce plants had been sold.
“The nature of online transactions makes it very difficult to identify where the plants may be,” she said.
“We encourage anyone who has purchased aquatic plants not to dispose of them, rather to contact the department so we can remove the weed to ensure it does not spread.”
Water lettuce is a free-floating plant with a dense rosette of overlapping leaves on a very short stem and long feathery roots.
Ms Martin said if the weed, which reproduces vegetatively and by seed, became established it could threaten waterways and the local ecosystem.
“Water lettuce has the potential to choke waterways, spreading over the entire surface of freshwater lakes, rivers and canals,” she said.
“The dense plant mass reduces light penetration, oxygen and pH levels in the water, destroying the local habitat, causing algal blooms and native fauna to die.”
Any sightings of water lettuce or other suspect weeds should be reported to the department’s Pest and Disease Information Service on +61 (08) 9368 3080 or email [email protected].