Pollution in the Great Barrier Reef

Sediment and chemical pollution from farms and land based runoff causes major damage to inshore coral reefs and seagrass meadows in our beautiful Great Barrier Reef.

These ecosystems are critical habitats for threatened dugongs, turtles and juvenile fish. Nutrients from fertiliser pollution in the Reef’s waters also fuels massive outbreaks of the coral-eating crown-of-thorns starfish, which devour our coral reefs.

By stopping farm and land based pollution, we are giving our Great Barrier Reef the clean water it needs to restore its health.

While climate change remains the biggest threat to our Great Barrier Reef, cleaning up the water that flows from the land reduces further pressure and helps our Great Barrier Reef to recover.


Water Quality and Land Based Runoff

When too much fertiliser is applied to crops, like sugar cane, excess fertiliser washes into rivers and waterways, where it is carried out to the Great Barrier Reef. Nitrogen from these fertilisers encourages the growth of algae, which is a food source for juvenile crown-of-thorns starfish. These starfish destroy vast amounts of coral and pose a huge threat to our Great Barrier Reef.

Pesticides and herbicides have been detected in high concentrations in inshore areas of the World Heritage Area and pose a further risk to marine plants and animals. Herbicides are applied to crops to kill weeds by inhibiting their ability to grow. But when they wash into the Reef, they also inhibit the growth of other non target plants, such as seagrasses, on which dugongs, turtles and fish depend.

Tree clearing and overgrazed grasslands cause soils to erode and wash into creeks and rivers that run into the Great Barrier Reef.

Sediment discharged from rivers reduces sunlight available to seagrasses and corals, which can smother coral growth. To reduce the sediment smothering our Reef, we need to maintain grass cover and protect the bush, especially along our rivers.

Satellite image of Fitzroy River flood plume, Queensland on the 8th of April 2017.
Photo credit: European Space Agency Sentinel 2 Mission

Excess fertiliser running off farms and into the Great Barrier Reef feeds crown-of-thorns starfish outbreaks. Nutrient pollution of the Reef’s waters is causing increased phytoplankton, which in turn boosts coral-eating crown-of-thorn starfish . As they grow, these starfish devour the corals on our Reef, causing vast damage and putting our Reef under intense pressure. Prior to the 2016 and 2017 bleaching events, AIMS found that crown-of-thorns starfish and tropical cyclones were the two leading causes of coral cover loss.

We can stop the plague proportions of crown-of-thorn starfish eating corals and give our Great Barrier Reef a fighting chance by stopping fertiliser pollution.

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We Support Sustainable Farming Practices

We all support our farmers. These proposed new regulations target farmers who are overusing fertiliser and polluting our Reef. Reducing fertiliser use will not only save money but will also reduce polluted runoff.

Since 2012 the Queensland Government has offered financial incentives to adopt safe farming practices, but it hasn’t worked. According to an ABC report, less than 10% have voluntarily adopted Best Management Practice.

Meanwhile our Reef is suffering.

The good news is that we secured an incredible opportunity to help our vulnerable Great Barrier Reef. 

In September 2019, the Queensland Government committed to new regulations that apply to agricultural, urban and industrial activities within Reef catchments to ensure they meet minimum pollution standards. These regulations will reduce sediment and chemical pollution and improve water quality – giving safe, clean water for our Reef.