Weed surveys on Croker and Goulburn Islands
In April 2024 Weed Officers Shelley Inglis and Russel O’Regan travelled to Croker and Goulburn Islands, northeast of Darwin in the Arafura Sea, to conduct weed surveys with the Northern Land Council (NLC) -funded Garngi and Mardbalk Ranger groups. Rangers were taught weed ID and shown various treatment options to deal with the species present on the island.
Locations across the breadth of the island were mapped and all species recorded in the ‘Weedmate’ app. The visit provided a great opportunity for two-way learning between NLC Rangers and Weed Management Branch (WMB) Officers about different weed and land management issues.
During the surveys, the high priority species Siam weed (Chromolaena odorata) was located near a remote outstation on the west of Croker Island. This was the first recording in Arnhem Land and a significant range extension from the known infestations within the Finniss and Reynolds catchments of the western Top End.
Finding Siam weed in such a remote location is a concern both locally and nationally. It re-opens the debate about the mobility of such a high impact weed and raises questions like how it may have got to Croker Island and where else it may be throughout the Northern Territory.
This survey and the resulting discovery pay testament to the viability of working together and highlights the expertise and skillset the dedicated Weed Management Officers have in weed identification. Because of the visit, new relationships are now formed and the Garngi Rangers are now well equipped to carry out further survey and treatment of Siam and other weeds on Croker Island.
