Removing weeds along the region’s riverbanks to improve water quality
Healthy Land and Water is currently delivering one of the most extensive invasive vine weed management projects undertaken in South East Queensland. Up to 148km of creek bank has been cleared of destructive weeds such as Cats Claw Creeper and Madeira over the past four years.
Where physical removal of the weeds has not been possible, biological control agents have been released into infestation to help stem the growth and spread of invasive vine weeds. The biological control agents are approved for release within Australia and sources from community groups.
The grazing and horticultural industries and councils are taking part in the initiative to help improve the condition of the region’s riverbanks and reduce the threats to water quality.
This project is an important part of Healthy Land and Water’s broader efforts towards a concerted war on weeds across South East Queensland, which has been actively rolling out on-ground works for more than 20 years.
About the project
- Managing invasive weed species in order to preserve water quality in water catchments that provide cities and town with drinking water.
- Improving the condition of the region’s riverbanks to protect biodiverty and provide habitat.
- Preventing sediment entering Moreton Bay.
Why this project is important
- The presence of foreign weeds is rapidly destroying South East Queensland’s precious ecosystems.
- These invasive weeds continue to thrive in our environment due to the lack of natural predators and their ability to outcompete native flora for resources such as space, nutrient and water.
- Infestations of invasive vine species along riverbanks and in rainforests have devastating effects on our region as they have the ability to overgrowth and kill mature trees. This results in mass erosion when trees fall resulting in dirty water quality, reduced fish stocks and loss of vital habitats that support our unique fauna, bird and reptile species.
This project is supported by Moreton Bay Regional Council and Seqwater.
The Healthy Land and Water weed control program manages invasive weed species like Cat’s Claw Creeper, Madeira vine and Chinese celtis in targeted locations across the region that have been identified by Seqwater as critical to maintaining water quality.
Where manual control is
not possible due to lack of access, cost or weed extent biological control agents are released. For Cats Claw Creeperr the agent of choice is Jewel Beetle, native to South America and raised in purpose-built facilities run by community groups. The beetle attacks the weed in two ways. Adult beetles feed on the growth tips of the plant and the larvae feast on the internal structure of the leaf once they emerge from the egg. This insect activity given time, weakens the plant, reducing seed set and allows other pathogens to take hold and reduce the weed’s vigour.
While biological control agents will never destroy the host plant entirely, their presence reduces the impact of the weed, giving the native vegetation a chance to recover and eventually outcompete the weed. Where conventional control methods can be expensive, difficult and very labour intensive, costs associated with biological control raising and release remain relatively low.
During the 2020 – 2021 financial year, more than 58,000 Jewel Beetles were released at 16 locations across South East Queensland, bringing the total beetles released to 90,000.
In of 2020 Healthy Land and Water partnered up with Cedar Grove Landcare to remove some 1.25 hectares of Cat’s Claw Creeper along Roberts Creek in Cedar Grove. Support to the group will be offered in future years to assist the community tackle local weed infestations.
Eradication of these weeds ensures the long-term sustainable delivery of cleaner water to water treatment facilities through the ecological services provided by the now healthier and recovering native vegetation.