After climate change, poor water quality is the biggest threat to the health of the Reef. Depending on how land is managed, pollutants such as sediment, pesticides and fertiliser can wash out to the Reef in large volumes, particularly after heavy rain events. These pollutants block sunlight; choke fish, seagrass and coral; trigger algal blooms; and cause population surges of the coral-feeding Crown-of-Thorns Starfish.
Stopping pollutants at the source, before they reach the Reef, is generally held to be the best approach. It’s a complex problem; however, there are proven science-based solutions. They tend to be expensive, but as more treatments are trialled, these approaches can be refined to maximise cost-effectiveness, and rolled out more widely.
One such practical solution being trialled by Greening Australia is rebuilding eroding gullies to stop sediment run-off and keep soil in place. Some of these gullies are metres deep, and with each heavy rain, they spread further, releasing thousands of tonnes of sediment.
Greening Australia’s Reef Aid program has shown that using earthworks to reshape the gullies, combined with surface stabilisation treatments, can reduce the amount of sediment running off from gullies by 90% almost immediately. These solutions have been found to be sustainable and stable, especially if vegetation cover is re-established to help prevent further erosion.
Restoring coastal wetlands is another practical solution for improving water quality, while also supporting biodiversity and improving habitat for bird and fish species. Healthy low-lying coastal wetland systems filter water as it flows through to the Great Barrier Reef, cutting pollution. In partnership with landholders, Greening Australia is trialling innovative methods for restoring and protecting wetlands, including installing bioreactors and treatment systems, and converting low productivity cane land into constructed wetlands.
We are – but the scale of the problem presents a real challenge to find the necessary funding to stop sediment and other pollutants at the source. The catchments emptying into the Reef lagoon spread over 420,000 square kilometres (over six times the size of Tasmania). To repair such large areas, and give the Reef the clean water it needs, will require a significant scaling up in investment.
When it comes to restoring eroding gullies, for example, there needs to be funding to build hundreds of kilometres of fences; help landholders implement more sustainable grazing management practices; and carry out large-scale earthworks and re-vegetation to take the eroding gullies back to a natural condition.
Greening Australia works with a variety of partners who help fund restoration efforts through Reef Aid. We have received support from the Australian and Queensland governments, and a matched funding arrangement meant that philanthropists, corporate partners and businesses have been able to come on board to help boost the investment available to help the Reef.
To secure the scale of finance needed, though, we really need a transformational change in how water quality improvement is funded in Australia. That’s one reason why we are partnering with GreenCollar and local landholders to generate Reef Credits – a market for water quality improvements.
Reef Credits provide landholders with a set payment for proven pollution reductions, providing an economic incentive to improve eroding gullies and restore wetlands. Reef Credits also give investors a return on their money and a sure-fire way of making a positive impact for the Great Barrier Reef.