AN environmental menace that has infested a lake at Laverton poses a serious threat to the state’s economy, the government has said.
Water hyacinth is known as one of the world’s worst waterweeds and its appearance in the Hobsons Bay lake has alarmed authorities.
Department of Primary Industries officers are trying to control the outbreak amid fears that it will spread to other waterways.
Agriculture Minister Joe Helper said the weed’s attractive spike of mauve flowers belied a “serious threat to the environment and the economy”.
He said the plant had been known to be harvested and sold illegally and the department was acting to ensure it did not end up in Victorian gardens.
“Water hyacinth is often considered to be an attractive pond plant despite its potential to cause serious environmental damage,” he said.
The government did not want the exact location of the outbreak revealed.
It presently covers about half a hectare.
“We are yet to find out where this infestation came from but we are concerned that the plant has been illegally traded or given away.”
The project manager of the department’s weed alert program, Neil Smith, said the plant had unusual “air balloons” in its leaf stems that allowed it to float on water.
“In the wild it can cause serious problems to waterways by doubling its growth every 12 days,” he said.
“An incursion management team has been formed to manage the outbreak with treatment expected to begin (last) Monday to prevent the infestation spreading to the nearby Kororoit Creek,” he said.
The imported plant has been declared a prohibited weed in Victoria because of its ability to spread quickly and damage the natural environment.
Mr Helper praised the actions of local volunteer weed spotters who reported the outbreak to authorities.
“Without the work of volunteers our chances of detecting these high risk weeds before they become established and spread into other parts of the state would be greatly reduced,” Mr Helper said.
Weeds are estimated to cost Australia’s economy about four billion dollars a year.
Mr Helper encouraged anyone who spots an outbreak of water hyacinth not to touch the plant and report it to the DPI by calling 13 61 86.
