Current conditions on the Reef

Each summer, we assess the health of reefs, as this part of the year poses a greater risk of extreme weather, particularly heat waves, cyclones and flooding.

Stressful conditions can lead to coral disease outbreaks, while poor water quality may make coral more susceptible to bleaching and lead to greater numbers of coral-eating crown-of-thorns starfish.

It’s important we have accurate, real time information on Reef conditions. Members of the public can report observations of coral bleaching, disease, predation or damage through the Eye on the Reef program.

Everyone can help support the Reef’s health and resilience by reducing greenhouse gas emissions, following responsible reef practices, including abiding by Marine Park zoning rules, not anchoring close to corals and responsibly disposing of litter.

Update 6: 5 May 2017 (end of summer wrap-up)

Overview of environmental conditions

Between December 2016 and April 2017, the Great Barrier Reef was exposed to heat stress from above average sea surface temperatures.

In line with predictions for an average cyclone season, one severe tropical cyclone – cyclone Debbie (category 4) - crossed the Queensland coast at Airlie Beach on 28 March 2017. On becoming an ex-tropical cyclone, the system then brought torrential rainfall and widespread flooding to parts of the central and southern regions of the Great Barrier Reef catchment.

In April 2017, sea surface temperatures in the southern half of the Great Barrier Reef Marine Park returned to average or below average, whilst temperature anomalies within the northern half generally ranged from 0.5o C to 2o C higher than long-term monthly averages.

As we approach winter, the Bureau of Meteorology’s May to July seasonal outlook for Queensland indicates the southern half of the state is likely to experience hotter than average temperatures, while the northern half is likely to experience average temperatures.  The whole state is likely to receive an average level of rainfall for this period.

The Bureau’s predictive modelling for the Great Barrier Reef indicates that sea surface temperatures are likely to decrease nearer to average in June.

The El Niño–Southern Oscillation (ENSO) remains neutral; however there is an El Niño watch, with a 50 per cent likelihood of an El Niño forming during 2017.

Our table of observations and forecasts provides more detailed information.

Reef health monitoring is ramped up over this time to keep an eye on the marine environment.

Overview of coral reef health reports

The Great Barrier Reef has been subject to multiple impacts this summer, including severe coral bleaching, outbreaks of coral disease and crown-of-thorns starfish, a severe tropical cyclone and subsequent flood plumes.

On 10 March 2017, the agency confirmed mass coral bleaching was underway on the Great Barrier Reef for the second consecutive year. The unprecedented heat stress experienced during summer 2015–2016, along with a warmer than average winter in 2016, means that corals have been under continued stress and were potentially more susceptible to bleaching and disease in early 2017.

The ARC Centre of Excellence for Coral Reef Studies conducted a comprehensive set of aerial surveys to determine the extent and severity of the 2017 bleaching event. Initial results indicate the general footprint of the 2017 bleaching event extends further south than the 2016 bleaching event. Reports of coral bleaching and high incidences of coral disease have also continued to come in through various networks.

On 28 March 2017, severe tropical cyclone Debbie (category 4) crossed the Queensland coast at Airlie Beach. Based on the cyclone’s characteristics, it is predicted that there is likely to be a high level of damage to reefs, islands, mangroves, seagrass meadows and other marine systems located along the cyclone’s path.

The Great Barrier Reef Marine Park Authority and Queensland Parks and Wildlife Service conducted initial in-water surveys of the Whitsundays Islands in early April. These surveys have revealed that some sites have suffered significant damage and are down to very low coral cover, while others received less damage and still have moderate coral cover.

Studies following previous extreme weather events revealed that even within severely damaged reefs, there were often areas that were relatively undamaged. These areas are critical for providing the next generation of corals and assisting with reef recovery. The full extent and severity of the damage to the region is yet to be determined.

On becoming an ex-tropical cyclone, the system then brought torrential rainfall and widespread flooding to parts of the central and southern regions of the Great Barrier Reef catchment. There was minor flooding of the Burdekin River and a small associated flood plume. The Fitzroy River stayed above flood levels for approximately six days, and the associated flood plume affected Keppel Bay.

Teams from the crown-of-thorns starfish control program have been assisting with surveys and reef recovery actions in the wake of the bleaching and cyclone events. The teams have also continued with scheduled crown-of-thorns starfish culling on selected reefs in the Cairns–Cooktown and Townsville-Whitsundays management areas to help protect corals. Since July 2015 more than 63,000 starfish have been culled from reefs of high tourism and ecological value in the Marine Park.

Further information on the mass coral bleaching event and Tropical Cyclone Debbie is available on the Reef Health page and our Timeline and Actions summary.

Want to help us keep an eye on the Great Barrier Reef?

Find out more about how you can get involved in our monitoring programs.

Latest detailed observed forecast and environmental conditions

Detailed information on sea surface temperature, tropical cyclones, rainfall levels and flood plumes to date.

Read more on Latest detailed observed forecast and environmental conditions

Eye on the Reef program

Eye on the Reef is a monitoring program that enables anyone who visits the Reef to contribute to its long-term protection.

Read more on Eye on the Reef program