This year the Illawarra District Weeds Authority will continue to build on previous efforts to control the State Biosecurity zone listed priority weed Bitou bush, by once again using drone technology.  The Weeds Authority will undertake a targeted surveillance and control program that uses a drone to help manage Bitou Bush, the invasive weed that threatens native plant and animal species and Endangered Ecological Communities along our coast.  The continued use of drones is part of a more innovative and targeted approach to managing Bitou bush in the Illawarra.

Bitou Bush is an aggressive weed in coastal dune and headland vegetation where it can out-compete, and in many cases totally eliminate, the native flora. Bitou Bush forms dense shrub layers which can obscure entire sand dunes and change views of headlands and beaches. The most destructive impact of Bitou Bush is a reduction of coastal biodiversity in infested areas. Bitou Bush is listed as a Weed of National Significance and a State priority weed under a Biosecurity zone listing. It is already directly affecting several threatened species and plant communities in the Illawarra.    

The use of drones is a completely different way to target the plant. Intelligent flight control with the assistance of the onboard technology, allows drones to achieve unimaginable precision, giving the drones the ability to be both targeted and versatile. They will be used to map out the target area and then with pinpoint accuracy control the plant via targeted spraying. This will eliminate the need for abseilers to spot spray around cliff faces and other hard to reach places.  Spray drift becomes minimal due to the precision and targeted accuracy of the drones.

The Weeds Authority 2026 program will also continue using the traditional control techniques of manual removal, revegetation and ground-based spraying. The drone technology will be used along a section of relatively inaccessible coastline at Bass Point reserve, Shellharbour and Gerringong cliff lines Gerringong. These sites are noted for their heavy infestations of the weed and limited accessibility by conventional methods. Met Mac 600®, a low toxicity unscheduled selective herbicide will be used in the work.

This year’s program follows a trial program first undertaken in 2022 at Bass Point which achieved excellent results. The work is scheduled to be undertaken in the week beginning the 3rd August and should be completed within the week, weather conditions permitting. 

Surveillance and control activities are unlikely to interfere with reserve activities, due to the remote nature of the site. There will be signage and staff on the ground to inform any people in the immediate area.

This work is funded through the NSW Government’s Crown Reserves Improvement Fund Program.