The primary goal of this project is to reduce the fine sediment loads delivered to the Great Barrier Reef lagoon. This will help to achieve the water quality targets set by the Reef 2050 Water Quality Improvement Plan. The project is funded by the Queensland Government's Natural Resources Investment Program.
Terrain NRM has begun working with grazing landholders in the Malanda and Ithaca Creeks on the upper catchment, and the Nerada area in the upper part of lower Johnstone, to target high risk locations.
Remediation activities include fencing, off-stream watering, erosion stabilisation, weed management, revegetation and grazing management practice changes. Land managers are also being supported through extension efforts, and knowledge and capacity building.
Why it’s important
Sediment is one of the major pollutants affecting the health of the Great Barrier Reef.
When fine sediment is suspended in water on the reef it blocks the sunlight from reaching the algae that photosynthesise the sunlight to gives coral its vibrant colours. The algae is dependent on sunlight for its survival.
In addition to coral, sea grasses also need sunlight to survive. Sediment can drop out of suspension, and kill or damage sea grass beds by smothering them, which also has a knock-on impact on mammals and fish that feed on them.
The Johnstone River catchment is one of the two highest priorities for sediment reduction in the Wet Tropics, and the fourth highest priority across the Great Barrier Reef catchments.
This project complements the Wet Tropics Major Integrated Project which is working with farmers in the lower Johnstone basin, and the Reef Trust IV Streambank and Gully Erosion project in the Herbert.
What causes sediment to reach the Reef
Erosion of subsoil contributes approximately 90 per cent of the fine sediment load delivered to the Reef.
Erosion became a problem after the introduction of livestock grazing and other catchment disturbances between 1850–1900.
The basalt soils within the Upper Johnstone catchment are easily eroded if disturbed, and due to their high clay content can lead to significant turbidity once they reach the GBR lagoon.
Factors contributing to the erosion of these soils include stock access to watercourses, grazing practices, bank erosion due to a lack of riparian vegetation, and the location of farm infrastructure such as dam spillways.
Who to contact
If you are a land manager in the Upper Johnstone and you would like to find out more about this project, please contact:
Jen Mackenzie on 0438 206343 or email@example.com
Evizel Seymour on (07) 4095 7108 or firstname.lastname@example.org