In 2011 Reef Catchments received funding through the Australian Government’s Caring for our Country program to eradicate pond apple from the Mackay Whitsunday Region over a period of three years. The project, which is actively supported by Mackay Regional Council, the Queensland Government, Pioneer Catchment Landcare and the Mackay Regional Pest Management Group, has entered the final six months of operations.
The Mackay Whitsunday Region is currently dealing with two infestations of pond apple. Interestingly, pond apple seems to behave differently in this region compared to more northerly regions, with normal prolific and dense stands growing upstream but stands downstream thinning and dying before reaching the mangrove systems of Reliance Creek and the Pioneer River catchments.
This unusual behaviour has aided control efforts, with about 21 ha successfully treated. Control methods include ‘cut and paste’ with either Round-Up Bio-Active or Vigilant for mature trees, and hand removal for seedlings. This has been highly successful, and all that remains of the control effort is to follow up on reshooting stumps and germination of the seed bank. Currently follow up occurs every six months, although this will drop back to once a year after the project’s completion. This will continue for three years in an attempt to ensure the complete eradication of the species from the area.
Unfortunately, as a consequence of the successful eradication of pond apple from a 2 km stretch of creek bank (a tributary of Lelia Creek), large gaps in vegetation have allowed those areas to become infested with other weeds. To reduce this secondary impact on plant biodiversity and water quality, weed removal and vegetation efforts are now underway in conjunction with Pioneer Catchment Landcare. It is hoped that through these efforts the creek system will be fully restored to its original state prior to the invasion of pond apple.
Reef Catchments is also working with the Queensland Department of Agriculture, Fisheries and Forestry to develop pond apple DNA detection in water bodies to aid on-ground survey efforts. This is being done in conjunction with work on DNA detection of Mimosa pigra. This work has only just begun, and we expect the results will be highly sought after.