Description: A floating fern with small, coarsely hairy oval leaves which repel water. As the plant

matures it turns from bright green to brown and bunches up into tight rafts. Reproduces by rapidly

dividing into smaller plants.

Distribution: A major weed of all river systems and connected wetlands in the lower Herbert. The

heaviest infestations are in the Cattle, Palm and Trebonne Creek systems.

Impacts: An aquatic weed that can choke waterways. It floats on still or slow-moving water and can

grow rapidly to cover the entire water surface with a thick mat of vegetation. This shades out any

submerged plant life and impedes oxygen exchange, making the water unsuitable for fish.

Key projects: Long term management projects are taking place in the Upper Cattle Creek, Palm Creek

and TYTO Wetlands reserve. These and other locations are also controlled by strategic releases of the

salvinia weevil which is an effective biological control agent.

Prevention Ongoing protection of the clean catchments identified within this Plan will

assist in the reduction of the spread of Salvinia. Ensure that Salvinia is not

introduced to ornamental ponds or water features.

Intensive

control

There are ongoing projects in Upper Cattle Creek, Palm Creek and TYTO

Wetlands reserve. There are limited resources available to expand current

scope of control programs at present.

Asset

protection

Targeted maintenance of key fish passage areas and high value wetlands in

the Palm and Cattle Creek systems will be ongoing as funding allows.

The Salvinia weevil biocontrol agent is an effective management tool in dense

infestations. The weevils are seasonal, often slowing down in the winter

months then re-emerging when warmer weather arrives. The weevil may

reduce the density and cover of an infestation but will not remove it

completely. In doing so they assist keep infestations at a manageable

threshold.

flower y y y y y y y y y y y y

vegetative x x x x x x t p t x x x

spray x x x x x x t p t x x x

manual x t p p t x x

biocontrol x x x x x x t p t x x x

J F M A M J J A S O N D

Salvinia molesta (Salvinia) P

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Biology x

Peak t

First/last flush p

Occasional y

n/a

Control x

Optimal t

Good p

Marginal y

Not recommended

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Restricted matter category

6

2.5/5 1.5/5 4.0/5 4.2/5 4.8/5 2.2/5 2.0/5 1.4/5 1.2/5

47

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Salvinia weevil

Control

Spread

What is my biosecurity obligation?

Prevention zone

Ensure any machinery or vehicles moving from the infested areas

are free from plant material and soil.

Intensive control

zone

Manage infestations systematically from top of catchment down.

Ensure best practice weed hygiene measures are in place to reduce

risk of spread to new locations. Maintain weed free areas.

Asset protection

zone

Ensure best practice weed hygiene measures are in place to reduce

risk of spread to new locations. Maintain weed free areas. Identify

high value assets and protect them from impacts where possible.

For more information on management aims in each zone refer to Using the Biosecurity Plan templates

Restricted matter category

48