IMPROVING COASTAL ECOSYSTEMS
POND APPLE CONTROL – HARD WORK, BUT WORTH IT
16 MARCH 2021
Pond apple, a major environmental weed, has been surveyed and removed from 115 hectares of land in the Murray catchment near Tully, in an effort to improve wetland habitat.
Introduced to Australia as grafting stock for commercially grown custard apple, pond apple has become a serious weed in Queensland. It is listed as a weed of national significance.
Aquatic weed management is part of Terrain NRM’s Fish Home & Highways project, which is improving fish habitat connectivity in the nationally significant wetland and coastal ecosystems of the Murray and Lower Herbert catchments.
Terrain NRM’s Deb Bass said the pond apple removal work builds on previous control efforts by Cassowary Coast Regional Council and Girringun Aboriginal Corporation in 2008 and 2015.
“Thanks to that work we had a good idea of areas to prioritise, and work was focussed along Warrami Creek. We’ll do a follow-up of the 115 ha next year to make sure everything has been caught, and we’ll then expand to take in more of the area previously surveyed.”
Local business NQ Forestry was contracted to undertake the on-ground control efforts.
The pond apple being targeted was along a creek line, so applying herbicide via stem injection is recommended. This minimised herbicide runoff and off-target impacts. However, each original stem maintains its own sap stream which complicates control – every single stem has to be cut and injected, not just the main stem.
“Pond apple control is labour intensive work, but this method is very effective and if we are consistent with control work we have a good chance of local eradication,” said Ms Bass.
Control work starts at the most upstream point because seed banks are carried downstream on water systems.
Other actions are also being taken to address threats to wetland habitat, and therefore fish habitat connectivity, including aerial spraying of 60 hectares of hymenachne, 300 hectares of feral pig control, and two hectares of riparian revegetation.
The Fish Homes & Highways project is funded by the Australian Government’s Reef Trust and delivered by Terrain NRM.