Insect to help control river weed
THE Gympie Region is supplying the expertise behind a radical new plan to free the Mary River of a plague of super-weeds, able to grow up to 9km long and large enough to bring down a bridge in a strong enough current.
The secret weapon, being brought to market-ready status is one insect that is not a pest.
Far from it.
A variety of water weevil being propagated at Gympie Landcare’s Old Maryborough Road facility, is the secret weapon in a major three-council campaign to rid the Mary of the declared aquatic weed, Salvinia molesta.
The weed, known for blanketing and clogging even major waterways, is rated as one of the biggest threats to the health of the Mary River, with an ability to grow to literally monstrous proportions.
The anti-weed campaign is being launched this morning by Sunshine Coast Regional Council Deputy Mayor Tim Dwyer, who will speak at the South East Queensland Pest Advisory Forum at Lake Kawana Community Centre.
The Mary River Aquatic Weed Strategy involves Sunshine Coast, Gympie and Fraser Coast councils, along with the Burnett Mary Regional Group and the Mary River Pest Management Group.
BMRG spokesperson Nora Brandli said yesterday funding for the project included a grant from the federal Caring for Country program.
Unprecedented measures incorporated in the plan include biological control, particularly the water weevils (Cyrtobagous salviniae) being bred at Old Maryborough Road.
The weevils eat aquatic weeds and reduce infestations to very low levels, a Sunshine Coast Regional Council spokesperson said yesterday.
“Left untreated, aquatic weeds are disastrous to the Mary River because they deplete the water of oxygen, killing fish including the endangered Mary River Cod, increase the cost of water treatment, pose a severe drowning risk for people and livestock and alter the ecosystem of the river, leading to changes in fauna, especially birds,” the spokesperson said.
While eradication is considered most unlikely on a regional scale, early detection and eradication in local areas is a good first step, especially in dams where they can easily move downstream.