Wetland Weeds Extracted By Excavator

A clever solution to an infestation of weed is reducing the need for herbicide while providing an alternative source of food for local graziers.

Reef Catchments is working to protect and restore wetlands south of Mackay, assisting landholders in the Sandringham Wetland Complex to manage their land and improve grazing practices.

As part of this project, which is funded by the Australian Government’s Reef Trust, a long reach excavator has been used in a trial effort to mechanically remove water hyacinth and put it into the adjacent fallow cane paddocks as mulch, as an alternative to spraying vast amounts of herbicides to control this localised infestation.

Reef Catchments and the landholder are now investigating if the mulch layer of aquatic weeds in the paddock will improve soil conditions and benefit the next cane crop, optimising the balance between production and ecosystem protection, promoting a healthier environment for the native birds and fish species, and reducing pollutants running off to the Great Barrier Reef lagoon.

The potential for biocontrol releases is also being investigated, which could deal with the infestation long-term, since the seed bank can be viable for up to 25 years.

The Plane Creek catchment, in which the Sandringham Wetland Complex is located, covers 2,539 square kilometres, and 28 per cent of the Mackay Whitsunday Isaac (MWI) region.

Reef Catchments is partnering with landholders in the Sandringham Wetland Complex to improve fish habitat, restore native vegetation and improve water quality. Reef Catchments has already assisted local landholders to implement more than 6.5km of new wildlife friendly fencing and 11 additional off-stream watering points to manage stock access in sensitive ecological areas.

Most wetlands in Queensland are on private land, and many are on properties that run grazing businesses.

Reef Catchments Project Officer – Conservation and Communities, Carlos Bueno, said “The Sandringham Wetland Complex provides many vital functions to the local coastal area due to its unique soil types and water holding capacity. Improvements and adoption of best management practices on these critical ecosystems can enhance the ecosystem and improve grazing productivity.

“Graziers value the Sandringham Wetland Complex for providing water and feed for stock, and reserves during the dry season or droughts. The impacts of grazing on wetlands can include reduced water quality from additional nutrient inputs, increased soil compaction and reduced native vegetation.”

Wetlands are the boundary between two different ecosystems, dry and wet, which means they have a unique role in nutrient exchange and water supply to surrounding lands. They also provide habitat, food, and shelter to many different plants and animals including endangered, vulnerable, and migratory species.

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