THREATS TO THE REEF
The challenges and threats to the Great Barrier Reef’s survival
The Great Barrier Reef is one of the most complex ecosystems on the planet. It’s home to thousands of species of marine life, including more than 1,600 species of fish, dolphins, whales, dugongs and six of the world’s seven species of marine turtles. It’s the largest living structure on earth and one of the seven natural wonders of the world.
But a range of threats are impacting the health of this critical ecosystem.
Climate change
Climate change is the biggest threat to the survival of the Great Barrier Reef and coral reefs around the world. Warmer water temperatures are causing more frequent and severe mass coral bleaching events and forcing marine species to move to cooler habitats, disrupting food supplies and breeding cycles and threatening entire ecosystems.
Ocean acidification is making it more difficult for corals to build skeletons and form reefs, while more frequent and intense weather events like cyclones, flooding and storms are battering the reefs that remain.
Poor water quality
Poor water quality is a major threat to the Great Barrier Reef. Pollutants create a constant pressure on Reef health, making it harder for marine life to survive and for the entire ecosystem to withstand other significant threats including the impacts of climate change.
Many of the pollutants found on the Reef typically start their journey on agricultural land in regional Queensland. When it rains, sediment, nutrients and pesticides wash into rivers and streams that flow out onto the Reef. These pollutants can smother corals and seagrasses, cause harmful algal blooms, and inhibit coral fertility and reproduction. There are 35 major waterways, or Catchments, across Queensland that run out to the Reef, the largest of which are the Burdekin, Burnett and Fitzroy catchments.
Crown-of-thorns starfish outbreaks
One of the most significant threats facing the Great Barrier Reef is crown-of-thorns starfish (COTS) outbreaks. These coral-eating creatures occur naturally on reefs in the Indo-Pacific region, including the Great Barrier Reef.
In normal numbers on healthy coral reefs, COTS are an important part of the ecosystem. They tend to eat the faster growing corals which gives the slower growing species a chance to catch up, enhancing the coral diversity of our reefs. However, when the starfish appear in outbreak proportions, they can strip a healthy reef of 90% of its corals.
Protecting the Reef
Reef Traditional Owners have been caring for land and sea Country for more than 60,000 years, using Traditional Knowledge passed down through ancestral lines for millennia.
Today, in partnership with the Great Barrier Reef Foundation, Traditional Owners are at the centre of the largest ever co-designed Reef protection effort. By combining Traditional Knowledge with Western science, they’re developing and applying innovative solutions to the challenges threatening coral reefs.