Past Reef health updates | Reef Authority

In addition to our regular updates, we’ve released Reef snapshot: summer 2022-23. We also released statements about the mass coral bleaching that occurred on the Reef and a statement on aerial surveys, along with educational information on coral bleaching.

We will resume weekly Reef health updates at the beginning of summer 2023-24.

Protecting the Great Barrier Reef over summer

While reef protection is a year-round effort, as we come into summer, we're monitoring Reef conditions closely and keeping an eye on the Reef.

Protecting the Great Barrier Reef requires a partnership involving the Australian and Queensland governments, Traditional Owners, scientists, Tourism operators and industries.

On the water and in the catchment, we're working together to protect the world's natural wonder.

While it's too early to tell exactly what summer will bring, local and regional conditions will ultimately influence Reef health outcomes; the Reef Authority remains focused on reducing cumulative pressures on the Reef.

Reef health update – October 2023

During October, most of the Marine Park experienced slightly below-average sea surface temperatures for this time of year, with temperatures increasing to slightly higher than average in the outer Southern region.

There was little to no rain over the Marine Park during October, making it the sixth driest October on record. The forecast remains at a 75 percent chance that the Marine Park will receive low rainfall in November.

El Niño conditions are expected to persist until at least April 2024, likely bringing drier and warmer conditions to the region. Forecast models predict that sea surface temperatures will peak in the period of February to March 2024.

Reef health

Of the 1447 Reef health surveys conducted between 1 October – 31 October 2023, 46 surveys recorded minor impacts of coral bleaching in the Marine Park.

Minor impacts of coral disease and damage were also reported in surveys across different regions of the Marine Park.

Crown-of-thorns starfish outbreak severity remains highest on reefs in the Swains (Outer Southern Region).

Reef management

The Reef Authority continues to maintain a close watch for any changes in Reef conditions.

We are working with our partners to protect and strengthen the resilience of the Reef through a range of management actions, including controlling the predatory coral-eating crown-of-thorns starfish and our year-round compliance campaign to deter illegal fishing.

If you are out in the Marine Park, you can report what you see through the Eye on the Reef app, and make sure you know your zones to help do your bit in protecting this World Heritage-listed natural wonder.

Reef health update – September 2023

This September marked the driest and the third hottest since records began in 1900.

During September, most of the Marine Park experienced above-average sea surface temperatures for this time of year, with temperatures surpassing monthly averages most often in the outer Southern region.

There is a 75 percent chance that the Marine Park will receive very little rainfall over the coming month.

Sea surface temperatures in the central and eastern Pacific continue to exceed El Niño thresholds. Models from the Bureau of Meteorology predict further warming of the eastern Pacific is likely in the coming months with a peak in the period of January to February this summer.

Reef health and management

Of the 808 Eye on the Reef program surveys conducted between 1 September – 30 September 2023, 32 surveys recorded minor coral bleaching in the Central region of the Marine Park.

Minor impacts of coral disease and damage were also reported in surveys across different regions of the Marine Park.

Crown-of-thorns starfish outbreak severity remains highest on reefs in the Swains (Outer Southern Region).

The Reef Authority monitors conditions on the Reef throughout the year, and particularly during summer.

We use a range of environmental monitoring tools including weather stations and satellite data, and work closely with partners to maintain awareness of Reef condition from in-water and aerial observations, as well as sightings submitted via the Eye on the Reef App and from Marine Park users.

We also remain focused on targeting direct threats to the Reef by prioritising actions such as enforcing Marine Park zoning rules and culling crown-of-thorns starfish to protect Reef resilience.

We continue to work with partners to address key threats through collaborative efforts.

Reef health update – August 2023

This month, the Bureau of Meteorology declared an El Niño event along with a positive Indian Ocean Dipole. When these two climate drivers occur together, they create a drying effect that is typically stronger and more widespread across Australia.

This weather event combination has the potential to reduce rainfall and increase atmospheric and sea surface temperatures.

This August was the tenth driest and the warmest winter on record, which was dominated by clear weather, often associated with warmer than average sea surface temperatures. Spring is also forecast to be warmer than usual across the country.

Below-average rainfall is likely for spring, along with warmer-than-usual temperatures.
Record high sea temperatures globally are likely to impact the weather experienced in Australia for many months.

At this point, the National Oceanic Atmospheric Administration (NOAA) Coral Reef Watch has not issued any bleaching warnings for Australia.

Reef health

Of the 2919 surveys submitted between 1 August – 1 September 2023, 1118 were Reef Health Impact Surveys (RHIS), and 32 of these reported mostly low impacts of coral bleaching.

These surveys, along with Rapid surveys and Tourism and Sightings reports, indicated that across the Marine Park, minor coral bleaching, disease, and damage continue to be reported.

The highest prevalence of low-impact coral bleaching was in the Central region of the Great Barrier Reef.
Crown-of-thorns starfish outbreak severity remains highest on reefs in the Swains (Outer Southern Region).

Reef management

The Reef Authority continues to maintain a close watch for any changes in Reef conditions.

If you are out in the Marine Park, you can report what you see through the Eye on the Reef app and make sure you know your zones to help do your bit in protecting this World Heritage-listed natural wonder.

Reef Health update – April 2023

The Reef experienced unseasonably warm conditions from early to mid-April; however, sea surface temperatures slowly cooled over the second half of the month.

The forecast for May is for dry and mild conditions for most of the Reef.

Along with our partners, the Australian Institute of Marine Science and the CSIRO, we will provide a wrap-up of the impact of the summer on Reef health with the release of the Summer Snapshot in the coming weeks.

Temperature and rainfall

The hotter-than-usual start to the month exposed much of the northern and central regions of the Reef to heat stress.

At the end of April, sea surface temperatures were, on average, 27°C across the Reef, which is 0.7°C above the long-term average for this time of year. The northern region experienced the highest anomalies at almost ~1°C above average.

Rain may continue across the Reef in the coming weeks due to a pulse in the Madden–Julian Oscillation, but this is not expected to greatly influence overall rainfall during the tropical dry season.

Reef health

Of the 1273 surveys submitted between 26 March and 26 April, 955 were Reef Health Impact Surveys (RHIS).

These surveys indicated that across the Marine Park, minor coral bleaching, disease, and damage continue to be reported. At the same time, anecdotal evidence of scattered bleaching was also received from the central region after the increase in temperatures earlier in the month.

Crown-of-thorns starfish outbreaks remain the most severe on reefs in the central and southern regions.
Reef management

While we have moved to our monthly updates, the Reef Authority continues to maintain a close watch for any changes in Reef conditions.

We are also continuing to work with our partners to protect and strengthen the resilience of the Reef through a range of management actions, including controlling the predatory, coral-eating crown-of-thorns starfish and our year-round compliance campaign to deter illegal fishing.

If you are out in the Marine Park, we ask that you please continue to report what you see through the Eye on the Reef app, and make sure you know your zones and do your bit to help protect this World Heritage-listed natural wonder.

Reef health activity in the Great Barrier Reef Marine Park and the Torres Strait

December 2022— April 2023

The Great Barrier Reef Marine Park Authority (the Reef Authority) is dedicated to gaining real- time information on Reef health throughout summer to better understand reef health impacts. This information helps the Reef Authority and its partners to prepare for any management response actions, such as planning surveys by vessel or aircraft.

Surveys during summer

To make sure we have the most up to date information and the best understanding of the conditions out on the Reef, the Reef Authority and its partners will be spending a lot of time on, above, or below the water.

Surveys can occur at any time and place in the Marine Park and may be conducted by partners including the Australian Institute of Marine Science (AIMS) and Queensland Parks and Wildlife Service (QPWS).

Keep a look out for snorkelers and divers surveying reef health in different areas around any one reef. Drones may also be used to take images of the reef from above.

When are Aerial surveys done?

If sea surface temperatures are warmer than average, the building heat stress could cause coral bleaching. If the Reef Authority receives reports of coral bleaching from multiple parts of the Reef, aerial surveys will be conducted to assess the extent.

Aerial surveys are conducted with small planes or helicopters, and survey activity is weather dependent for visibility and safety. They are flown at low altitudes and slow speeds above the water, weaving among the reefs, allowing trained observers to assess any impacts.

Have something to report?

Anyone can contribute to reef health reporting on impacts like bleaching, or even just interesting observations, through the Eye on the Reef program on the Great Barrier Reef Marine Park Authority website. Non-emergency incidents like pollution or injured marine animals can also be reported on the Incident Reporting page.

Reef Health update – week ending 31 March 2023

Temperatures have cooled across the Reef again in the past week, with sea surface temperatures approximately 0.4°C above average for this time of year.

Dry and mild conditions are expected to persist across most of the Marine Park catchment for the next week.

This is our last weekly Reef health update for the summer season; however, we continue to closely monitor conditions on the Reef throughout the cooler weather and will publish monthly updates during this time.

Along with our science partners, we will provide a wrap-up of the impact of the summer on Reef health with the release of the Summer Snapshot at the end of April.

Temperature and rainfall

Sea surface temperatures are down on last week and are now near average for this time of year in the northern region and slightly above average in the central and southern regions.

Across the Reef, sea surface temperatures are about 28°C on average.

La Niña has ended, and the recent and rapid decline in the Madden–Julian Oscillation has reduced the likelihood of rain over northern Australia in the coming weeks.

Reef health

Almost 300 surveys have been submitted from across the Reef in the past fortnight, including 189 Reef Health Impact Surveys.

Minor coral bleaching was reported mostly in the central region of the Marine Park, while minor coral disease and damage were reported across all regions.

Crown-of-thorns starfish outbreak severity remains highest on reefs in the central and southern regions.

Reef management

While the hotter months are coming to an end, the Reef Authority will continue to maintain a close watch for any changes in Reef conditions.

We are continuing to work with our partners to protect and strengthen the resilience of the Reef through a range of management actions, including controlling the predatory, coral-eating crown-of-thorns starfish and our year-round compliance campaign to deter illegal fishing.

We’d like to thank all of you who have helped us keep an eye on conditions over the summer with reports through the Eye on the Reef app and ask that if you are heading out into the Marine Park that you know your zones and continue to do your bit to help protect this World Heritage-listed natural wonder.

We will move to monthly updates from now, with a summer wrap-up scheduled for later next month.

Our weekly updates will return at the start of next summer.

Reef health update – week ending 24 March 2023

Cooler weather over the past week has seen temperatures decrease across the Reef to about 0.8°C above average.

While La Nina has now ended, the likelihood of entering El Niño conditions has been forecast for later this year.

Temperature and rainfall

With higher-than-average sea surface temperatures over recent weeks, the Bureau of Meteorology has revised its forecasts, predicting an increased likelihood of temperatures exceeding 0.6°C above average for the next few weeks for most of the Reef.

The increase in sea surface temperatures means additional heat stress has accumulated throughout the Marine Park for March, although not the same amount of stress experienced during the summer months.
Monsoonal conditions are likely to end in the coming weeks with rainfall already subsiding in the north.

Reef health

The Reef Authority has received 521 surveys from across the Marine Park over the past fortnight, including 351 Reef Health Impact Surveys (RHIS).

Minor impacts of coral disease and damage were reported in all regions of the Marine Park, with minor coral bleaching reported mostly in the central region.

Crown-of-thorns starfish outbreak severity remains highest on reefs in the central and southern regions.

Reef management

The Reef Authority is continuing to maintain a close watch for any changes in conditions in the Reef as the hotter months end.

We continue our work with partners to protect and strengthen the resilience of the Reef through a range of management actions. These include controlling the predatory, coral-eating crown-of-thorns starfish and our year-round compliance campaign to deter illegal fishing.

You too can do your bit to help by reporting what you see out on the Reef through the Eye on the Reef app and to ensure that if you are heading out on the water, you know your zones.

Our next Reef health update will be published on Friday, 31 March 2023.

Reef health update – week ending 17 March 2023

Warmer weather over the past week has seen temperatures increase across the Reef to about 1°C above average.

While La Nina has now ended, tropical storms will continue in the north but not with the same intensity experienced in late February.

Regional weather systems over the coming weeks will remain critical in determining the overall impact of the summer on Reef health this year.

Temperature and rainfall

With increased sea surface temperatures, the Bureau of Meteorology has revised its forecasts, predicting an increased probability of temperatures exceeding 0.6°C above average for the next few weeks for most of the Reef.
The increase in sea surface temperatures means additional heat stress has accumulated throughout the Marine Park.

Rainfall is expected to continue across the northern catchments for the coming week.

Reef health

The Reef Authority has received 385 surveys across the Marine Park over the past fortnight, including 322 Reef Health Impact Surveys (RHIS).

Minor impacts of coral disease and damage were reported in all regions of the Marine Park, with minor coral bleaching reported mainly in the central region.

Crown-of-thorns starfish outbreak severity remains highest on reefs in the central and southern regions.
Reef management

Reef management

The Reef Authority continues to maintain a close watch for any changes in conditions in the Reef as the hotter months end.

You too can do your bit to help by reporting what you see out on the Reef through the Eye on the Reef app and to ensure that if you are heading out on the water that you know your zones.

Our next Reef health update will be published on Friday, 24 March 2023.

Reef Health update – week ending 10 March 2023

Temperatures have remained about average across the Marine Park for this time of year, while the monsoon continues to deliver heavy rainfall in the northern tropics causing low-level flooding.

Regional weather systems over the coming weeks will remain critical in determining the overall impact of the summer on Reef health this year.

Temperature and rainfall

Sea surface temperatures have been relatively stable for the past week, not exceeding the long-term March average by more than 0.5°C.

Heat stress has also been minimal over the past fortnight.

Heavy rainfall has been reported across the northern catchments, causing low coastal salinity and localised flooding.

The Bureau of Meteorology predicts temperatures across the Reef will not likely exceed 0.5°C above average for the remainder of the month.

Reef health

More than 220 surveys have been submitted from across the Marine Park over the past fortnight, including 172 Reef Health Impact Surveys (RHIS).

Minor coral bleaching was reported mainly in the central region of the Marine Park, while minor coral disease and damage were reported primarily in the central and southern areas.

Crown-of-thorns starfish outbreak severity remains highest on reefs in the central and southern regions.

Reef management

While the hotter months are drawing to a close, the Reef Authority maintains a close watch for any changes in conditions.

You, too, can do your bit to help by reporting what you see on the Reef through the Eye on the Reef app and ensuring that if you are heading out on the water, you know your zone.

Our next Reef health update will be published on Friday, 17 March 2023.

Reef Health update – 3 March 2023

Temperatures have continued to cool in the past week, with sea surface temperatures below average for most of the Marine Park, while the monsoon continues to deliver heavy rain in the northern tropics.

Regional weather systems over the coming weeks will remain critical in determining the overall impact of the summer on Reef health this year.

Temperature and rainfall

Heat stress has been minimal over the past fortnight, with most of the Reef experiencing below-average temperatures.

Heavy rainfall has been reported across the Cape York catchment caused by a low-pressure system off the Queensland coast.

The Bureau of Meteorology predicts temperatures across the Reef won’t exceed 0.5°C above average for the remainder of the month.

Reef health

More than 580 surveys have been submitted from across the Marine Park since 15 February, including 396 Reef Health Impact Surveys (RHIS).

Minor coral bleaching was reported mostly in the central region of the Marine Park, while minor coral disease and damage were reported mostly in the central and southern regions.

Crown-of-thorns starfish outbreak severity remains highest on reefs in the central and southern regions.

Reef management

Reef Authority continues to monitor conditions closely and along with our partners, and we remain prepared to conduct aerial surveys should they be required.

This week our Acting Chief Scientist, Dr Jessica Stella, joins us from Fitzroy Island in the far northern Great Barrier Reef, where the Reef Authority has been leading Reef protection training for Master Reef Guides.

The training will enable guides to better manage and protect the tourism sites they work at along the Reef, with skills covering techniques to help injured or stranded marine life and practical, safe, and effective methods for incident reporting.

The guides have also been learning more about Traditional Use of Marine Resources Agreements – TUMRAs – which describe how Traditional Owner groups work in partnership with the Australian and Queensland governments to manage traditional use activities on their Sea Country.

Master Reef Guides work with High Standard Tourism Operators throughout the Marine Park, educating visitors about the Reef, its management and protection through responsible reef practices and providing us with firsthand information about what is happening on the Reef.

Many Reef tourism operators partner with the Reef Authority, providing valuable information through the Eye on the Reef program, contributing to Reef Health and Impact Surveys and Tourism Weekly Monitoring.

You, too, can do your bit to help by reporting what you see out on the Reef through the Eye on the Reef app.

Our next Reef health update will be published on Friday, 10 March 2023.

Reef Health update – week ending 24 February 2023

With continued cloud cover and rain over much of northern Queensland over the past week, sea surface temperatures have cooled and are approaching average for this time of year.

The monsoon remains active bringing more rain in the northern catchments of the Marine Park.

Regional weather systems over the coming month will be critical in determining the overall impact of the summer on Reef health this year.

Temperature and rainfall

Sea surface temperatures have fallen to about 0.4°C above average across the Reef over the past week and are continuing to fall.

Heavy rainfall was reported across the far north and northern catchment areas last week, with falls of between 50–300mm. Monsoon conditions are forecast to continue for the coming week.

The Bureau of Meteorology is predicting temperatures across the Reef won’t exceed 0.5°C above average for the remainder of summer.

Reef health

ore than 480 surveys have been submitted from across the Marine Park since 8 February, including 263 Reef Health Impact Surveys (RHIS).

Minor coral bleaching, disease, and damage have been reported across the central region of the Marine Park.

Crown-of-thorns starfish (COTS) outbreaks remain the most severe across the southern and central regions of the Reef.

Reef management

With a month left of summer, the Reef Authority continues to monitor conditions closely.

The Reef Authority and its partners remain prepared for aerial surveys should they be required.

You can do your bit by reporting what you see in the Marine Park through the Eye on the Reef app, with reports of healthy coral just as important as reports of bleached or diseased coral.

Next week we’ll be joining you from Fitzroy Island in the far northern Great Barrier Reef for our Reef Health update, Friday, 3 March 2023.

Reef Health update – week ending 17 February 2023

Due to increased cloud cover, conditions have been near or slightly above average across the Marine Park in the past week.

Monsoon conditions remain in Northern Queensland, with increased rain, thunderstorms and tropical low-pressure systems.

Regional weather systems over the coming month will be critical in determining the overall impact of the summer on Reef health this year.

Temperature and rainfall

While sea surface temperatures have warmed to just above average for the past fortnight across the Marine Park, most of that still is within the moderate range of around 0.5°C above average.

The Bureau of Meteorology indicates La Niña conditions continue to weaken, however ongoing monsoonal activity is likely across northern Australia.

Heavy rainfall (50–300mm) has been reported across some northern and far northern catchments and is expected to continue into next week.

Reef health

More than 480 surveys have been submitted from across the Marine Park since 1 February, including almost 300 Reef Health Impact Surveys (RHIS).

Minor coral bleaching, disease, and damage have been reported across the Marine Park.

Crown-of-thorns starfish (COTS) outbreaks remain the most severe across the southern and central regions of the Reef.

Reef management

The Reef Authority will continue to closely monitor forecast conditions and near real-time climate and weather observations, as well as collating in-water reports.

Our teams are ready to conduct aerial surveys with our partners if needed.

We are also estimating any potential impacts on the Reef from high seas in the wake of Tropical Cyclone Gabrielle.

You can do your bit by reporting what you see in the Marine Park through the Eye on the Reef app.

Reports of healthy coral are just as important as reports of bleached or diseased coral.

Our next Reef health update will be released on Friday, 24 February 2023.

Reef Health update – week ending 10 February 2023

Conditions have warmed across the Marine Park in the past week.

Tropical Cyclone Gabrielle has intensified and is expected to reach category 3 today.

While Gabrielle is expected to move away from Queensland, the system has brought higher wind and rain activity to coastal regions.

Monsoonal conditions are returning to northern Queensland next week, with an increased chance of rain, thunderstorms, and tropical low-pressure systems.

Regional weather systems over the coming month will be critical in determining the overall impact of the summer on Reef health this year.

Temperature and rainfall

While sea surface temperatures have warmed to slightly above average across the Marine Park, most of this remains within the moderate range of less than 0.6°C above average.

The Bureau of Meteorology predicts sea surface temperatures may reach up to 0.8°C above average in parts of the outer Reef in the coming weeks.

Heavy rainfall of 150-200mm has been reported across some northern and far northern catchments, which is expected to continue into next week.

Reef health

Almost 600 surveys have been submitted across the Marine Park since 26 January, including almost 400 Reef Health Impact Surveys (RHIS).

Minor coral bleaching continues, particularly in the central region, while minor impacts from isolated damage and coral disease have also been reported across the Marine Park.

Crown-of-thorns starfish (COTS) outbreaks remain the most severe across the southern and central regions of the Reef.

Reef management

The Reef Authority will continue to closely monitor forecast conditions and near real-time climate and weather observations, as well as collating in-water reports.

Our teams are ready to conduct aerial surveys with our partners if needed.

We will also monitor for any potential impacts on the Reef from Tropical Cyclone Gabrielle over the next few days.

You can do your bit by reporting what you see in the Marine Park through the Eye on the Reef app.

Reports of healthy coral are just as important as reports of bleached or diseased coral.

Our next Reef health update will be released on Friday, 17 February 2023.

Reef Health update – week ending 3 February 2023

Conditions have remained mostly favourable across the Marine Park over the past week.

Flood plumes resulting from recent heavy rain have entered the Marine Park, particularly in the Princess Charlotte Bay area of the Reef’s northern region.

Temperature and rainfall

Sea surface temperatures are near or just above average across the Marine Park.

Heavy rain with the return of monsoon conditions is likely to occur in the coming weeks across the Marine Park, particularly in the northern region.

The Bureau of Meteorology is predicting sea surface temperatures to remain slightly above average for the next few weeks.

Reef health

Some minor coral bleaching in the central and southern regions has been reported in surveys across the Marine Park. Minor impacts from isolated damage and coral disease were also reported in those regions.

Flood plumes in the Princess Charlotte Bay area have potentially exposed local reefs and seagrass meadows to low-salinity waters. Potential impacts are being monitored.

Crown-of-thorns starfish (COTS) outbreaks are still most severe in the Reef’s central and southern regions.

Reef management

We are continuing to collaborate with our partners to protect and strengthen the resilience of the Reef through our management actions, including controlling the coral-eating crown-of-thorns starfish and deterring illegal fishing.

The Reef Authority also collaborates with partners in managing the Great Barrier Reef Marine Monitoring Program which supplies crucial flood monitoring throughout the wet season.

You can do your bit to help by reporting what you are seeing out in the Marine Park through our Eye on the Reef app. Reports of healthy coral are just as important as reports of bleached or diseased coral.

Our next Reef health update will be released on Friday 10 February 2023.

Reef Health update – week ending 27 January 2023

Conditions have been mostly favourable across the Marine Park this week, with temperatures close to average for the end of January. Monsoon conditions have eased over Northern Australia in the past week, however recent flooding has caused flood plumes to enter the Marine Park, particularly in the Cape York, Mackay and Whitsundays regions.

Temperature and rainfall

Sea temperatures have remained near or just above average across the Marine Park and are expected to remain so for the coming week. Monsoon conditions will return next week with average rainfall forecast across most of the Marine Park, and heavy falls expected across the Cape York region.

The Bureau of Meteorology is predicting above average sea surface temperatures for the remainder of summer, but with a low probability of exceeding those averages by more than 1°C. Temperatures have been slightly higher in some offshore locations.

Reef health

Mostly minor bleaching was reported in surveys conducted across the northern and central Reef, while isolated physical damage and minor coral disease were reported on a low number of reefs in the central and southern regions. Crown-of-thorns starfish (COTS) outbreaks remain the most severe in the Reef’s central and southern regions.

Reef management

As summer progresses, the Reef Authority continues to closely monitor forecast conditions and near real-time climate and weather observations, as well as collating in-water reports to build a current picture of Reef health. Preparations are in place for aerial surveys should they be required. We are continuing to work with our partners to protect and strengthen the resilience of the Reef through our management actions, including controlling the coral-eating crown-of-thorns starfish and deterring illegal fishing.

You can do your bit to help by reporting what you’re seeing out in the Marine Park through our Eye on the Reef app. Reports of healthy coral are just as important as reports of bleached or diseased coral.

Our next Reef health update will be released on Friday 3 February 2023.

Reef Health update – week ending 20 January 2023

Intense rainfall caused flooding in some rivers throughout the Great Barrier Reef Marine Park catchment this week. Sea temperatures were near average across the Marine Park and are expected to remain for the short term.

Temperature and rainfall

As floodwaters subside following the high levels of rainfall, flood plumes may extend into some areas of the Marine Park.

The Bureau of Meteorology predicts above average sea surface temperatures for the remainder of summer, but with a low probability of exceeding those averages by more than 1°C. Temperatures have been slightly higher in some offshore locations.

Reef health

Mostly minor impacts from bleaching, isolated physical damage and minor coral disease were reported from a low number of reefs in the central and southern regions of the Reef this week.

Crown-of-thorns starfish (COTS) outbreaks remain the most severe in the Reef’s central and southern regions.

Reef management

Many of our partners have commenced their summer season programs and are beginning to submit reports during their trips on Reef health.

When out in the Marine Park, please report your sightings through our Eye on the Reef app. It is important for us to know what you may be seeing across the vast expanse of the Reef. Reports of healthy coral are just as important as reports of bleached or diseased coral.

Our next Reef health update will be released on Friday 27 January 2023.

Reef Health update – week ending 13 January 2023

After a hotter than usual start to summer, temperatures around Queensland remained around average for the past week. High rainfall of between 150-400mm was recorded in the Cape York region.
La Niña conditions continue to weaken, with the Bureau of Meteorology predicting a return to neutral conditions in March.

Temperature and rainfall

Sea surface temperatures in the Marine Park are near average, with some areas 0.5°C above and some 0.5 °C below average to the north and south of Mackay, respectively.

The Bureau of Meteorology is forecasting sea surface temperatures for the northern and central regions to remain slightly above average for the rest of summer.

Reef health

Isolated low intensity bleaching has been reported in some parts of the Reef, with most reports of minor impact.

Minor impacts of disease and damage have also been reported – mostly around the central region of the Reef.

Regional weather conditions over the next few weeks will influence the risk of coral bleaching.

Crown-of-thorns starfish outbreaks remain the most severe in the central and southern parts of the Reef.

Reef management

We are continuing to work with our partners to protect and strengthen the resilience of the Reef through our management actions, including controlling the coral-eating crown-of-thorns starfish and deterring illegal fishing.
Many of our partners have commenced their summer season programs and are beginning to submit reports during their trips on Reef health.

When out in the Marine Park, please report your sightings through our Eye on the Reef app. It is important for us to know what you may be seeing across the vast expanse of the Reef.

Reports of healthy coral are just as important as reports of bleached or diseased coral.

Reef health update – week ending 6 January 2023

Above average temperatures were experienced in the lead up to summer and into December across the Marine Park. La Niña conditions continue, however the Bureau of Meteorology predicts a return to neutral conditions late this month or in February. The Bureau of Meteorology is forecasting increased rainfall across northern and eastern Australia.

Temperature and rainfall

Persistent cloud cover in the northern Great Barrier Reef hindered accurate satellite sea surface temperature data, however Australian Institute of Marine Science (AIMS) weather stations indicated near average temperatures.

The Bureau of Meteorology is forecasting above average sea temperatures for January and February, but mainly in the north. Forecasts thereafter predict more average sea surface temperatures, remaining around 0.5°C above average until April.

There has been heavy rainfall across the Marine Park catchment area north of Cairns in the past week, between 200 and 400mm, while infrequent rainfall occurred south of Townsville.

Air temperatures were below average for the past week across Queensland.

Reef health

Recent sea surface temperatures have seen a downgrading of bleaching risks for the Great Barrier Reef.

Over the Christmas period, we received a small number of minor impact bleaching reports, with most located in the central region of the Marine Park.

Minor impacts of coral disease and damage were reported mostly in the central region.

Crown-of-thorns starfish outbreaks remain the most severe in the central and southern parts of the Reef, with previously reported outbreaks offshore in the Whitsundays being investigated and addressed.

Reef management

As summer progresses, the Reef Authority is closely monitoring forecast conditions and near real-time climate and weather observations, as well as collating in-water reports to build a current picture of Reef health.

When out in the Marine Park, please report your sightings through our Eye on the Reef app.

It is important for us to know what you may be seeing across the vast expanse of the Reef. Reports of healthy coral are just as important as reports of bleached or diseased coral.

Many of our partners are currently in their summer season programs and have begun submitting reports on Reef health. Targeted surveys will also increase as required.

The Reef Authority will continue to work with our partners to protect and strengthen the resilience of the Reef through our management actions, including controlling the coral-eating crown-of-thorns starfish and deterring illegal fishing.

Our next Reef health update will be released on Friday, 13 January 2023.

Reef Health update – week ending 23 December

It’s been a hot build-up to summer, with above-average temperatures throughout spring and into December across the Marine Park.

La Niña conditions are continuing for the remainder of December, with the Bureau of Meteorology forecasting an increased chance of rain across northern and eastern Australia over the next couple of weeks.

Temperature and rainfall

Sea surface temperatures across the Marine Park are near one degree above average. The Bureau of Meteorology is forecasting this to continue into January for most of the Marine Park; however, cooler conditions are expected around the Mackay/Capricorn area.

Rainfall across the Marine Park catchment in the past week was greatest around Cairns, between 100-300mm.

Given global warming, sea surface temperatures have increased to the level where coral bleaching is likely to happen more frequently and over a larger extent in the Great Barrier Reef.

Reef health

There is a building risk of coral bleaching this summer, given the higher-than-average sea surface temperatures recorded in spring and continued forecasts for warmer-than-average conditions.

Reports gathered over the past few weeks show isolated bleaching of low intensity in some parts of the Reef, with most reports of minor impact. Minor impacts of disease and damage have also been reported.

Crown-of-thorns starfish outbreaks remain the most severe in the central and southern parts of the Reef, with emerging outbreaks recorded offshore in the Whitsundays.

Reef management

The Reef Authority is closely monitoring forecast conditions and near real-time climate and weather observations, as well as collating in-water reports to build a current picture of Reef health. If you are in the Marine Park over the holidays, please report your sightings through the Eye on the Reef app. It is important for us to know what you are seeing across the vast expanse of Reef. Reports of healthy coral are just as important as reports of bleached or diseased coral.

Many of our partners have commenced their summer season programs and are beginning to submit Reef Health reports. Preparations have commenced for targeted surveys as required and are likely to increase from now.

We will continue to work with our partners to protect and strengthen the resilience of the Reef through our management actions, including controlling the coral-eating crown-of-thorns starfish and deterring illegal fishing.

Our next Reef health update will be released on Friday, 6 January 2023.

Reef Health update – week ending 16 December

Heatwave conditions have impacted Queensland over the past week, bringing hotter than average conditions across parts of the state.

La Niña conditions are continuing in December with the Bureau of Meteorology forecasting an increased chance of rain across northern Australia over the next week or two.

Neutral conditions are expected to return in January or February 2023.

Temperature and rainfall

Rainfall was low across the Marine Park over the past week, with no rain recorded in the far north.
Sea surface temperatures remained about 1°C above average, with temperatures slightly higher south of the Whitsundays.

Air temperatures were average along the Queensland coast, although heatwave conditions did affect certain areas in Queensland, bringing higher than-normal temperatures.

Thermal stress is accumulating across the Marine Park, and we will be closely monitoring as summer progresses.

Reef health

There is an increased risk of coral bleaching, given the higher-than-average sea surface temperatures recorded in spring and current warmer-than-average conditions. Crown-of-thorns starfish outbreaks are the most severe on reefs in the central and southern parts of the Marine Park, with emerging cohorts being recorded offshore in the Whitsundays.

Reef management

The Reef Authority will continue to monitor conditions across the Marine Park as summer progresses. Preparations have commenced with our partners for targeted surveys as required and are likely to increase from now.

Many of the Reef Authority’s partners have commenced their summer season programs and are beginning to submit reports from their trips on Reef health.

You can do your bit to help by following zoning rules when out in the Marine Park and reporting sightings of what is going on across the Reef through our Eye on the Reef app.

Reef Health update – week ending 9 December

The Marine Park has experienced a hotter-than-average lead into summer, and La Niña conditions are continuing in December. The Bureau of Meteorology is predicting a return to neutral conditions in January or February 2023.

Temperature and rainfall

Sea surface temperatures were about 1°C above average north of Mackay and offshore across the southern Reef this week but are near average inshore south of Mackay. Thermal stress is accumulating across the Marine Park, and we will be closely monitoring as summer progresses.

Air temperatures in early December were below average for most of the Marine Park catchment; however, there has been a rapid change over the past few days, with heatwave conditions now affecting most of Queensland. Air temperatures are 4 to 8°C above average inland and 2 to 4°C above average along the coast.

Rainfall was uniform along the Queensland coast, with the highest falls recorded in the state’s southeast.
There is an increased risk of coral bleaching, given the higher-than-average sea surface temperatures recorded in spring and forecasts for a warmer-than-average summer.

Reef health

Twenty-two Reef health impact surveys were conducted on three reefs across the Marine Park in the past week with no bleaching reported on the surveyed reefs. However, bleaching was reported on a few reefs offshore of the southern Marine Park at the end of November.

Crown-of-thorns starfish outbreaks are the most severe on reefs in the central and southern parts of the Marine Park, while emerging cohorts continue to be recorded in the north.

Reef management

The Reef Authority is continuing to work with partners to protect and strengthen the resilience of the Reef through a range of management actions, including controlling the coral-eating crown-of-thorns starfish and the summer compliance campaign to deter illegal fishing.

You can do your bit to help by following zoning rules when out in the Marine Park and reporting sightings of what is going on across the Reef through our Eye on the Reef app.

November 2022

Hotter and wetter than average conditions have persisted across the Marine Park in November.

La Niña conditions are expected to continue through to the new year, with the Bureau of Meteorology predicting a return to neutral conditions in January or February 2023.

Temperature and rainfall

The month of November was the hottest November on record on the Reef, with most of the Marine Park recording sea surface temperatures up to 2°C above average. Rainfall was above average for the month, with up to 400mm recorded in the southern half of the QLD coast.

There is an increased risk of coral bleaching, given the higher-than-average sea surface temperatures and forecasts for a warmer than average summer.

Reef health

Reef health impact surveys are continuing across the Reef, with 409 surveys conducted across 46 Reefs throughout the Marine Park in November, mostly by crown-of-thorns starfish control program vessels.

Isolated reports of minor coral bleaching have been reported across the Reef, including recent reports of bleaching on a few reefs in a small area of the Swains.

Crown-of-thorns starfish outbreaks are the most severe in the central and southern regions of the Reef, however emerging cohorts continue to be recorded in the north.

Reef management

The Reef Authority hosted its annual pre-summer workshop with management partners, scientists, and Marine Park users at the end of November.

Presentations from the Bureau of Meteorology, the National Oceanic and Atmospheric Administration, and others informed participants of current forecast models. The workshop also discussed responses in the event of extreme weather events on the Reef.

We will continue to monitor conditions across the Marine Park throughout summer and preparations have commenced with our partners to conduct targeted surveys as required.

You can do your bit to help by following zoning rules when out in the Marine Park and reporting sightings of what is going on across the Reef through our Eye on the Reef app.

October 2022

Continuing La Niña conditions along with other climate drivers are expected to increase rainfall along the east and north-eastern coast for the remainder of the spring and into summer.

The Bureau of Meteorology continues to predict a return from La Niña to neutral conditions in early 2023.

Temperature and rainfall

Rainfall was above average across the state, particularly in the south with Queensland recording its wettest October since 2016. Air temperatures were cooler than average in the south of the state, but above average across the Cape York Peninsula.

The Great Barrier Reef experienced its second hottest October on record. Sea surface temperatures in the northern regions were about 2.5°C above average. South of Mackay, above average temperatures were only reported during the second half of the month.

Reef health

Reef health impact surveys (RHIS) are continuing across the Reef, with 150 surveys conducted across 13 reefs mostly by crown-of-thorns starfish (COTS) control program vessels.

Reef health impact survey (RHIS) efforts were concentrated mainly in the central reef, with surveys also conducted across the northern and southern regions of the Reef.

Low impact bleaching was recorded on some isolated reefs across the Marine Park; however the National Oceanic Atmospheric Administration (NOAA) reports the Marine Park was not under any bleaching stress in October.

Reef management

The Reef Authority continues to work with its partners to protect and strengthen the resilience of the Reef through a range of management actions, including controlling the coral-eating crown-of-thorns starfish and the summer compliance campaign to deter illegal fishing.

The Reef Authority will host its annual workshop with partners, scientists, and Marine Park users at the end of

November with the aim of sharing information and determining appropriate responses in the event of extreme weather affecting the Reef ahead of summer.

You can do your bit to help by following zoning rules when out in the Marine Park and reporting sightings of what is going on across the Reef through our Eye on the Reef app.

September 2022

La Niña conditions are expected to continue into early 2023, bringing above average rainfall for northern and eastern Australia.

Bureau of Meteorology modelling predicts a return to neutral conditions in early 2023.

Temperature and rainfall

Rainfall was above average across the state with Queensland recording its wettest September since 2016.

Air temperatures were above average for northern Queensland for the month but were cooler than average in the state’s south.

The Great Barrier Reef recorded its third hottest September on record with sea surface temperatures between 0°C and 2°C hotter than average north of Mackay, while temperatures to the south of Mackay were 0°C to -1.5°C below average in the inner reef and up to 1°C above average in parts of the outer reef.

Reef health

Crown-of-thorns Starfish (COTS) outbreaks continue to impact reefs across the Marine Park, with the main outbreaks in the central and southern regions. Emerging cohorts of COTS continue to be reported in the northern region.

Reef health impact surveys (RHIS) indicate minor bleaching on isolated reefs in the Marine Park this month. The National Oceanic Atmospheric Administration (NOAA) reports the Marine Park was not under any bleaching stress in September.

Reef management

You can do your bit to help by following zoning rules when out in the Marine Park and reporting sightings of what is going on across the Reef through our Eye on the Reef app.

Synopsis of the 2022 mass bleaching event

The surveys confirm a mass bleaching event, with coral bleaching observed at multiple reefs in all regions. This is the fourth mass bleaching event since 2016 and the sixth to occur on the Great Barrier Reef since 1998.

In 2022, 60 per cent of the total Reef area experienced heat stress capable of causing coral bleaching (>4°C-weeks-<8 °C-weeks). Compared to 2016 and 2017, a smaller percentage of reefs experienced heat stress with Degree Heating Week values above 8 °C-weeks in 2022.

Surveys were conducted after the final heat wave in March 2022, however, the coral colony response to heat stress can be prolonged and bleaching may progress, and recovery processes will occur over the next six to eight months.

It is important to note that bleached coral is stressed but still alive. As water temperatures cool, bleached corals may regain their colour and survive this stress event, as happened in 2020 when there was very low coral mortality associated with a mass bleaching event.

As outlined in the Great Barrier Reef Authority’s Position Statement on Climate Change, climate change is the greatest threat to the Great Barrier Reef. Only the strongest and fastest possible actions to decrease global greenhouse gas emissions will reduce the risks and limit the impacts of climate change on the Reef. Further impacts can be minimised by limiting global temperature increase to the maximum extent possible and fast-tracking actions to build Reef resilience.

Findings of the 2022 aerial surveys

The Great Barrier Reef’s waters warmed early in December 2021, exceeding historical summer maximums that typically occur in the hottest summer months.

Ocean temperatures continued to accumulate heat throughout the summer until early April 2022, with three distinct heat waves increasing thermal stress throughout the Central and Northern Great Barrier Reef.

This prolonged heat exposure led to a mass bleaching of coral across the Great Barrier Reef; the fourth to occur in seven years.

Unusually, this was the first mass bleaching event to occur under La Niña conditions.

Increased reports of coral bleaching prompted Reef-wide aerial surveys in the second half of March 2022 to assess the extent of coral bleaching.

Aerial surveys were conducted by trained observers from the Great Barrier Reef Marine Park Authority and the Australian Institute of Marine Science.
A total of 719 reefs were surveyed from the air between the Torres Strait and the Capricorn Bunker Group in the Great Barrier Reef Marine Park.
Of these, 654 reefs (91 per cent) exhibited some bleaching. Coral bleaching observed from the air was largely consistent with the spatial distribution of heat stress accumulation, with a greater proportion of coral cover bleached on reefs that were exposed to the highest accumulated heat stress this summer.
The 2022 Aerial Survey Map illustrates the variation in bleaching observed across the Reef in the latter half of March.

Results by region

Northern region - includes coral reefs from the tip of Cape York down to Lizard Island and Cape Tribulation:

The pattern of shallow-water coral community bleaching as seen from the air varied from minor (1-10 per cent coral cover bleached) to severe (61-90 per cent bleached), with severity generally increasing from the northern tip of Cape York down towards Princess Charlotte Bay. Coral cover and the community composition were important factors influencing community bleaching severity through this region, with many reefs dominated by temperature tolerant massive Porites, which did show signs of bleaching at the more impacted sites in southern Princess Charlotte Bay.

Central region - includes reefs from Cape Tribulation, south to the Whitsundays.

The onset of coral bleaching around the Townsville region was captured during a preliminary aerial survey of 43 reefs in early February 2022, after a prolonged period of thermal stress. These preliminary surveys found 87 per cent of reefs exhibited minor to moderate bleaching (11-30 per cent bleached).

Reef-wide surveys in the second half of March found the pattern of reef community bleaching, as seen from the air, increased in severity compared to early February, following additional heat stress. Community bleaching ranged from major (31-60 per cent bleached) to extreme (>90 per cent bleached) on the shallow parts of reefs from Cooktown to the Whitsundays.

The most severe bleaching occurred on both inshore and offshore reefs throughout this region. Inshore, mid and outer-shelf reefs between Lizard Island and Townsville had a higher abundance of tabular Acropora corals on the shallow reef flats and crests, compared to the Northern and Southern regions.

Southern region - includes reefs from the Pompey Reef area down to the Capricorn-Bunker area and out to Swain Reefs.

Within the southern region, bleaching was highly variable, reflecting the boundary of lower heat stress exposure. Some shallow-water coral communities in the southernmost parts of the Reef exhibited no bleaching (around the Capricorn Bunker Group), with others further north exhibiting major to severe community bleaching offshore Mackay.

Image below: 4 February 2022 Townsville Aerial Survey Map 2

Great Barrier Reef aerial surveys as of 4 February 2022 - Great Barrier Reef - Copyright Commonwealth of Australia - (Reef Authority) — **Map 2:** Early onset of bleaching in the Townsville region assessed with aerial survey observations of reef community following initial reports from in water observation. Aerial survey conducted 4 February 2022.

Aerial surveys[1] are an important and reliable method to provide a broad assessment of coral bleaching across the scale of the entire Reef. These surveys are conducted from low-flying aircraft, at slow speed and targeted around low tide.

Trained observers can document the percentage of visible bleached coral (white or fluorescent colours) among the shallow-water coral community on the Reef flat and upper-reef slope (in waters less than 6 metres deep). Visually assessing coral reef community bleaching severity involves assigning each area of a reef surveyed to one of six bleaching categories (see map legend).

The NOAA Coral Reef Watch Degree Heating Week product provides an estimation of accumulated heat stress, which can lead to coral bleaching and mortality.

Based on this product and on past mass bleaching events, significant coral bleaching usually occurs when the Degree Heating Week value exceeds 4 °C-weeks.

If the Degree Heating Week value exceeds 8 °C-weeks, severe, widespread bleaching is likely and the risk of coral mortality increases.

Aerial surveys were timed to coincide with the peak in accumulated Degree Heating Week and completed within a 12-day period (from 12-23 March 2022).

Importantly, aerial surveys quantify reef-scale community bleaching severity as an assessment of how much of the living coral community is bleached – not individual coral colony severity.

In-water surveys provide more detailed information on coral colony health, including the intensity of bleaching (not bleached, partially bleached, or fully bleached) and colony mortality.

In-water surveys also allow assessment of bleaching in deeper water, which is important as bleaching typically lessens in intensity with depth.

In-water surveys on reefs throughout the Great Barrier Reef will be combined with the broad-scale results from the aerial surveys to help document the impacts of this 2022 mass bleaching event.

[1]. The aerial bleaching survey method was developed in 1998 in response to the first-ever recorded mass bleaching event on the Great Barrier Reef. It continues to be refined and is described in an AIMS Standard Operating Procedure.

Map 2: Early onset of bleaching in the Townsville region assessed with aerial survey observations of the reef community following initial reports from in-water observation. An aerial survey was conducted on 4 February 2022.

As Australia’s lead management agency for the Reef, we monitor Reef conditions very closely throughout the year. From May to November each year, we issue regular Reef health reports. Over summer, we issue weekly public reports on the conditions of the Reef.

These updates are based on forecasts, water temperature heat mapping, in-water surveys, citizen science and aerial surveys. The current updates are available below and past Reef health updates are also available.

In addition to our regular updates, we’ve released: Educational information on coral bleaching.

July - August 2022

The Bureau of Meteorology’s El Niño-Southern Oscillation Outlook has been raised to La Niña. Modelling indicates the event may peak during spring and return to neutral conditions early in 2023.

A La Niña events increases the chance of above-average rainfall for northern and eastern Australia during spring and summer.

Temperature and rainfall

Rainfall across Queensland was well above average for both July and August - with both months the wettest on record since 2016.

Air temperatures were cooler than average for most of the state in July and August, however the Cape area was warmer than average in August.

Sea surface temperatures were within one degree of average throughout most of the Marine Park.

In July, sea surface temperatures were slightly warmer north of Townsville – 1- 2°C above average. But that cooled north of Cairns in August with temperatures about 2°C below average.

The Marine Park was not under any bleaching stress in July or August.

Reef health

Preliminary assessments indicate that coral mortality will be much lower for the 2022 mass bleaching event compared to the 2016 and 2017 events, with a smaller amount of Reef exposed to extreme heat stress.

The outcome of the bleaching event in terms of coral mortality will be known after the next round of long-term monitoring surveys, which conclude in April 2023.

Reef management

You can do your bit to help by following zoning rules when out in Marine Park waters and reporting sightings of what is going on across the Reef through our Eye on the Reef app.

Reef health update - June 2022

The Great Barrier Reef Marine Park Authority, along with our partners, is continuing to monitor conditions across the Marine Park and assess the impact of this summer’s mass bleaching event.

Temperature and rainfall

Above-average air temperatures were experienced in the northern regions of the Reef, while southern regions experienced cooler than average temperatures.

Sea surface temperatures are between -1°C and 1°C on average for this time of year throughout most of the Marine Park. However, there was some warming from north of Cairns to the tip of the Cape York Peninsula of up to 1-2.5 °C above average.

Statewide rainfall for June 2022 was 32% below the long-term average, although a few areas in the north of the state experienced their highest June rainfalls on record (daily and total).

The National Oceanic and Atmosphere Administration report the Marine Park is no longer under bleaching stress.

Reef health

With recent surveys and environmental conditions indicating the mass bleaching event is ending, the extent of recovery versus mortality following accumulated heat stress can only be estimated once the Australian Institute of Marine Science Long-Term Monitoring Program surveys are completed in mid-2023.

For June 2022, seven out of 12 reefs where reef health assessments were completed reported some level of bleaching, all low in extent with severity ranging from bleached upper surface only to recent mortality. Of the 91 Reef Health Impact Surveys performed throughout June, just under 16 per cent recorded coral bleaching.

Crown-of-thorns starfish continue to impact Reef Health across all management areas. The most severe outbreaks are occurring on reefs in the central and southern regions, and with an emerging contingent of Crown-of-thorns identified in the northern region.

Crown-of-thorns Control vessels are continuing their surveillance monitoring and culling operations in the northern, central, and southern management areas.

Reef management

Preliminary assessments indicate that coral mortality will be much lower for this mass bleaching event compared with those in 2016 and 2017. This is not unexpected given the smaller amount of Reef area that was exposed to extreme heat stress, i.e., greater than eight Degree Heating Weeks (DHW).

A degree heating week assists with predictions of impacts from a bleaching event. It is a cumulative measurement of both intensity and duration of heat stress over a 3-month period, which increases the chance of heat stress levels leading to bleaching or mortality when degree heating weeks accumulate.

The Reef Authority continues to work with our partners to monitor the Reef by collecting data with in-water surveys. This information helps us to better understand the effects of this bleaching event and the impacts on individual coral colonies.

We are also continuing our work to protect and strengthen the resilience of the Reef through management actions, such as controlling coral-eating starfish and enforcing compliance on the water to deter illegal fishing.

You can do your bit to help on the water by following zoning rules in the Marine Park and reporting sightings of what is going on across the Reef through the Eye on the Reef App.

Reef Health Update - June 2022

The Great Barrier Reef Marine Park Authority, along with our partners, is continuing to monitor conditions across the Marine Park and assess the impact of this summer’s mass bleaching event.

Temperature and rainfall

Above-average air temperatures were experienced in the northern regions of the Reef, while southern regions experienced cooler than average temperatures.

Statewide rainfall for June 2022 was 32% below the long-term average, although a few areas in the north of the state experienced their highest June rainfalls on record (daily and total).

The National Oceanic and Atmosphere Administration report the Marine Park is no longer under bleaching stress.

Reef health

Crown-of-thorns Control vessels are continuing their surveillance monitoring and culling operations in the northern, central, and southern management areas.

Reef management

You can do your bit to help on the water by following zoning rules in the Marine Park and reporting sightings of what is going on across the Reef through the Eye on the Reef App.

Weekly Reef Health update – May 2022

Sea surface temperatures are steadily going down as winter settles in.

The Great Barrier Reef Marine Park Authority, along with our partners, is continuing to monitor conditions across the Marine Park and assess the impact of this summer’s mass bleaching event.

Temperature and rainfall

May 2022 was the 5th wettest May on record and the wettest in the last 32 years, with exceptional rainfall over large parts of Queensland.

Sea surface temperatures are 22-26°C south of Townsville and 26-28.5°C north of Townsville and are close to the average for the season throughout most of the Marine Park. However, the Far North has recorded temperatures 1-2°C above average.

The National Oceanic and Atmosphere Administration report the Marine Park is no longer under bleaching stress.

Reef health

With recent surveys and environmental conditions indicating the mass bleaching event is ending, the extent of ‘recovery versus mortality’ following heat stress can only be estimated once the Australian Institute of Marine Science Long-Term Monitoring Program surveys are conducted from September 2022 to April 2023.

For May 2022, 19 out of 23 reefs were reported to have bleached, all of the low extent, with severity ranging from bleached upper surface only to recent mortality. Of the 285 Reef Health Impact Surveys performed throughout May, just under 89 (31 per cent) recorded coral bleaching. This included nine reefs in the Cairns /Cooktown Management area, four reefs in the Townsville/Whitsundays MA and seven reefs in the Mackay/Capricorn MA.

The map of aerial survey bleaching scores of the recent mass bleaching event is available here, along with detailed explanations of the methodology used.

Crown-of-thorns starfish continue to impact Reef health across all management areas. Intensive culling operations continue at various reefs to suppress Crown-of-thorns starfish numbers and protect coral in the Northern, Central and Southern regions.

Particular attention is being made to the Crown-of-thorns starfish outbreak initiation area in the Northern region with increased surveillance and culling to reduce adult Crown-of-thorns starfish numbers and suppress spawning.

Reef management

Preliminary assessments indicate that coral mortality will be much lower for this mass bleaching event compared with those experienced in 2016 and 2017. This is not unexpected given the smaller amount of Reef area that was exposed to extreme heat stress.

The Reef Authority is working with our partners to prioritise a sub-set of reefs for in-water surveys to help us better understand the intensity of this bleaching event and the impacts on individual coral colonies.

You can do your bit to help on the water by following zoning rules in the Marine Park and reporting sightings of what is going on across the Reef through the Eye on the Reef App.

Weekly Reef Health update – 22 April 2022

Sea surface temperatures continued to decrease across the whole Marine Park during the past week.

The Reef Authority, along with our partners, is continuing to monitor conditions across the Marine Park and assess the impact of this summer’s mass bleaching event.

Temperature and rainfall

Sea surface temperatures are 0–1°C above average throughout the southern half of the Marine Park, and 1–2.5°C in the northern half, but overall temperatures are cooler than those experienced on the Reef in recent months.

A low over the Coral Sea may has developed close to Queensland's tropical east coast, affecting areas from Cooktown to Townsville. Even if this system does not intensify significantly, it is expected to produce heavy rainfall over parts of Queensland's North Tropical Coast District which may continue for much of the coming week.

Reef health

Coral bleaching has been observed across multiple regions of the Marine Park, via in-water surveys completed by our Eye on the Reef network, industry partners and researchers. Surveys have recorded impacts ranging from low to extreme. Completely white colonies and some coral mortality have been observed in areas where heat stress accumulation was the highest.

The results of the recent aerial surveys conducted by the Reef Authority and our partners at the Australian Institute of Marine Science (AIMS) are being finalised.

Reef management

You can do your bit to help on the water by following zoning rules in the Marine Park, and reporting sightings of what is going on across the Reef through the Eye on the Reef app.

Weekly Reef Health update – 15 April 2022

Conditions have remained relatively stable across the Marine Park in the past week, with a slight drop in sea surface temperatures. However, they are still above average for this time of year.

The Reef Authority, along with our partners, is continuing to monitor conditions across the Marine Park to fully assess the impact of this summer’s mass bleaching event. This includes in-water surveys of the impacts on coral colonies.

Temperature and rainfall

Sea surface temperatures are between 0.5–2°C above average for mid-April throughout most of the Marine Park, but overall these temperatures are cooler than those experienced on the Reef in recent months.

The Bureau of Meteorology is forecasting temperatures of up to 1°C above average in the northern parts of the Reef, and less than 1°C above average in the southern parts for the latter part of April.

Reef health

Coral bleaching has been observed across multiple regions of the Marine Park, ranging in impact from low to extreme. Completely white colonies and some coral mortality have been observed in areas where heat stress accumulation was the highest.

The results of the recent aerial surveys conducted by the Reef Authority and our partners at the Australian Institute of Marine Science (AIMS) are being finalised.

Reef management

The Reef Authority is working with our partners to prioritise reefs for in-water surveys to help us better understand the intensity of this summer’s bleaching event, and its impact on individual coral colonies. The full impact of this bleaching event on the Reef will only be known after the next round of Long-term Monitoring Program surveys.

You can do your bit to help on the water by following zoning rules in the Marine Park, and reporting sightings of what is going on across the Reef through the Eye on the Reef app.

Weekly Reef Health update – 8 April 2022

Despite the fact that summer is now over a month behind us, the coral bleaching event, and our understanding of it, are still unfolding.

The Reef Authority is working with partners to prioritise a sub-set of reefs for ongoing in-water surveys. These are providing more detailed information about bleaching intensity, mortality and the depth range of bleaching impacts.

As with every summer, the final outcome of this bleaching event in terms of mortality will only be known after the next round of surveys from the Australian Institute of Marine Science’s Long-term Monitoring Program.

Temperature and rainfall

Sea surface temperatures in March were some of the hottest on record since 1900, in the Northern and parts of the central Great Barrier Reef. The southern Reef was also above average but not by as much.

Sea surface temperatures have stabilised over the last week but the monthly average for April is lower than for March, so the temperature anomalies are higher than last week- with anomalies of 1-2°C above average throughout most of the Marine Park. It is unlikely that monsoon conditions will redevelop across northern Australia before the end of the current wet season. The Bureau of Meteorology is forecasting sea surface temperatures of 1-1.5°C above average for areas north of Mackay and 0.8-1°C south of Mackay.

Reef health

In water observations of coral bleaching across multiple regions of the Marine Park vary greatly in severity of bleaching, whether or not mortality is occurring and the depth range over which bleaching is happening. An increasing number of surveys are reporting completely white colonies and coral mortality where heat stress accumulation has been highest through a broad area of the central Reef.

Reef management

You can do your bit to help by following zoning rules when out in the Marine Park, and reporting sightings of what is going on across the Reef through the Eye on the Reef app.

Weekly Reef Health update – 1 April 2022

Temperatures across the Reef have moderated and remain lower and more stable than the first couple of weeks of March, which saw heatwave conditions. Last week the Reef Authority and the Australian Institute of Marine Science (AIMS) concluded aerial surveys and confirmed a mass bleaching event on the Reef.

Bleaching was observed at multiple reefs in all four management areas of the Reef, which is largely consistent with the spatial distribution of the heat stress experienced over summer. It is important to note that bleached coral is stressed but still alive. If conditions moderate, bleached corals can recover from this stress.

The Reef Authority is now working with its partners to conduct in water surveys to complement the aerial surveys. This will provide more detailed information about bleaching intensity, mortality and depth range of bleaching impacts.With most of the Marine Park continuing to experience the effects of significant heat stress, localised weather patterns will remain critical in determining the overall extent and severity of coral bleaching.

Temperature and rainfall

Sea surface temperatures across the Reef remain up to one degree above average for this time of year. The areas between Innisfail, north of Townsville, and Mackay having accumulated the most heat stress over summer.

The La Niña weather pattern has passed its peak but its influence will persist until late autumn. While tropical lows are still developing around northern Australia they are expected to stay weak. The Bureau of Meteorology is forecasting sea surface temperatures will remain between 0.6─1°C above average into early April around Townsville and Mackay, while temperatures in the Far North and the Cairns region are expected to remain about 1─1.5°C above average.

Reef health

The Reef Authority and AIMS have completed aerial surveys covering about 750 reefs from the Torres Strait to the Capricorn Bunker Group. The data from these surveys is being analysed, however preliminary observations indicate most reefs surveyed had bleached coral. Early results from in-water monitoring are variable. Some early mortality has been observed in areas where heat stress accumulation has been the greatest, while in others areas the bleaching is not as intense and corals are expected to recover in the next few weeks.

Reef management

The Reef Authority is working with its partners to prioritise reefs for in-water surveys to help better understand the intensity of this bleaching event, and the impacts to individual coral colonies. We are continuing to work to protect and strengthen the resilience of the Reef through our management actions, such as controlling coral-eating starfish and enforcing compliance on the water to deter illegal fishing.

You can also do your bit to help on the water by following zoning rules in the Marine Park, and reporting sightings of what is going on across the Reef through the Eye on the Reef app.

Reef Health update – 25 March 2022

The Reef Authority, together with our partners at the Australian Institute of Marine Science, have completed aerial surveys across a representative sample of 750 reefs on the Great Barrier Reef. Aerial surveys are a standard method which provide the best picture of the full spatial extent of bleaching severity at many reefs across a large, representative area of the Great Barrier Reef Marine Park.

The bleaching observed from the air was largely consistent with the spatial distribution of the heat stress experienced. Coral bleaching has been observed at multiple reefs in all four management areas (Far Northern, Cairns–Cooktown, Townsville–Whitsunday and Mackay–Capricorn), confirming a mass bleaching event, the fourth since 2016 and despite La Niña conditions.

It is important to note that bleached coral is stressed but still alive. If conditions moderate, bleached corals can recover from this stress, as was the case in 2020 when there was very low coral mortality associated with a mass bleaching event. Weather patterns over the next couple of weeks continue to remain critical in determining the overall extent and severity of coral bleaching across the Marine Park.

Temperature and rainfall

Sea surface temperatures have cooled in the past fortnight and are now less than 0.5°C above average throughout most of the Marine Park. Temperatures at some inshore areas around Cairns, and southern areas around Mackay were below average for this time of year. However, the Bureau of Meteorology’s model forecasts sea surface temperatures will remain close to 1 to 1.5°C above average for the rest of the month, with the exception of the areas south of Mackay which are expecting temperatures of about 0.4 to 1°C above average. The United States National Oceanic and Atmospheric Administration (NOAA) anticipates the heat stress will dissipate in most of the Marine Park by end of April.

Reef health

The bleaching across the Marine Park is variable, which is consistent with the levels of heat stress experienced across the Reef this summer. In the Far North, bleaching is variable between reefs and ranges from minor to severe. In the Northern and Central regions bleaching is mostly severe and we observed some mortality.

Reefs in the south have mostly minor bleaching. Some of the high coral cover reefs in this region had no visible bleaching at all. Mass bleaching events do not affect every reef, and even those reefs affected are not all equally affected. The intensity of bleaching varies between different reefs and different locations on a single reef, influenced by what type of coral is growing, depth and currents, and the level of heat stress experienced.

Reef management

The Reef Authority, along with our partners at the Australian Institute of Marine Science, is continuing to analyse data gathered over the past fortnight, however aerial surveys can only reliably observe shallow corals, down to about five metres. As such we are also conducting in-water surveys at selected reefs to get a better idea of the depth profile of bleaching.

We are working hard, along with our partners, to protect and strengthen the resilience of the Great Barrier Reef through our management actions, such as controlling coral-eating starfish and enforcing on-water compliance to deter illegal fishing. The Reef remains a vibrant and beautiful ecosystem. Impacts from climate change and extreme weather are a reminder of the importance of global greenhouse gas emissions reduction and strong marine management actions that support the resilience of this magnificent living ecosystem. You can also do your bit out on the water by following zoning rules in the Marine Park, and reporting sightings of what is going on across the Reef through the Eye on the Reef app.

Weekly Reef Health update – 18 March 2022

The past week has brought cooler temperatures to the Reef bringing an end to the heatwave conditions of late February and early March. Despite this, sea surface temperatures remain above average across most of the Marine Park and are expected to remain so until the end of March. Weather patterns over the next few weeks will be critical in determining the overall extent and severity of coral bleaching across the Marine Park.

The Reef Authority will continue to closely monitor forecast conditions and near real-time climate and weather observations, and will collate in-water and aerial surveillance observations and reports for an up-to-date picture of the Reef.

Temperature and rainfall

During the past week, sea surface temperatures have ranged between 0.5 to 2°C above average throughout the Marine Park. However, parts of the Far North and inshore areas between Townsville and Rockhampton varied between 2 to 4°C above average. Most of the Marine Park has accumulated significant heat stress over the summer, with the central Reef experiencing the highest heat stress accumulation.

There is an increased likelihood of above average cloud and rain across northern Australia in the coming week. The Bureau of Meteorology expects sea surface temperatures will remain close to 1°C above average for the rest of the month.

Reef health

Bleaching has been detected across the Marine Park — it is widespread but variable, across multiple regions, ranging in impact from minor to severe. Most observations of bleaching have been of paling or fluorescing but several locations have whole colonies bleached white. This is consistent with the patterns of heat stress experienced on the Reef this summer. The most heavily impacted reefs are around the Townsville region. There have also been reports of early mortality where heat stress has been the greatest. Corals across the Marine Park remain vulnerable to the ongoing elevated temperatures.

Reef management

The Reef Authority and the Australian Institute of Marine Science have been conducting aerial surveys in the Far Northern Great Barrier Reef (including Torres Strait) and from just north of Townsville to offshore Bowen. The data from these surveys is being analysed. Aerial surveys across the whole of the Reef are continuing.

The surveys conducted have been concentrated in areas of greatest heat stress, the Central Reef, and the Far North, where information was previously lacking. Aerial surveys have not yet been conducted over the major tourism areas such as Cairns and Port Douglas, as heat stress has been less in these areas, and in water observations suggest corals here have not been severely impacted.

Our Crown-of-thorns starfish (COTS) Control Program, along with our partners at the Great Barrier Reef Foundation and the Reef and Rainforest Research Centre, has increased COTS surveillance and culling between Cairns and Mackay. Our management actions, such as controlling coral-eating starfish and enforcing compliance on the water to deter illegal fishing, help protect the Reef and aid recovery from weather events.

You can do your bit to help by following zoning rules when out in the Marine Park, and reporting sightings of what is going on across the Reef through the Eye on the Reef app.

Weekly Reef Health update – 11 March 2022

Conditions on the Reef have changed little during the past week, with the heatwave continuing and sea surface temperatures remaining above average across most of the Marine Park. Warmer conditions are expected for the rest of March, and heat is continuing to accumulate across the Marine Park.

Weather patterns over the next few weeks will be critical in determining the overall outcome for the Reef this summer, with coral bleaching already reported in many parts of the Marine Park. The Reef Authority will continue to closely monitor forecast conditions and near real-time climate and weather observations, and will collate in-water and aerial surveillance observations and reports for an up-to-date picture of the Reef.

Temperature and rainfall

Sea surface temperatures are generally about 1 to 1.5°C warmer than average for this time of year throughout most of the Reef, while temperatures of up to 3°C above average are occurring in parts of the central Reef. The hottest temperatures have been recorded around the Townsville region.

Large areas between Innisfail and Rockhampton have accumulated significant heat. The Bureau of Meteorology is forecasting sea surface temperatures will remain at least 1°C above average across the Marine Park for the rest of the month.

Reef health

Coral bleaching is being reported across multiple regions of the Marine Park, mostly of low to moderate severity. This is consistent with the patterns of heat stress experienced on the Reef this summer. The most heavily impacted reefs are in the Townsville region. Corals in these areas remain vulnerable to the ongoing elevated temperatures.

Reef management

The Reef Authority is preparing to conduct aerial spot checks of coral health in areas of highest heat stress accumulation. Our Crown-of-thorns starfish (COTS) Control Program, along with our partners at the Great Barrier Reef Foundation and the Reef and Rainforest Research Centre, has increased COTS surveillance and culling between Cairns and Mackay.

Our management actions, such as controlling this coral-eating starfish and enforcing compliance on the water to deter illegal fishing, help protect the Reef and aid recovery from weather events. You can do your bit to help by following zoning rules when out in the Marine Park, and reporting sightings of what is going on across the Reef through the Eye on the Reef app.

Reef Health update – 4 March 2022

Recent heatwave conditions combined with low cloud cover along the central Marine Park have caused a slight increase in sea surface temperatures in the past week, heralding an end to the milder conditions experienced in mid-February.

Given the warmer weather, conditions over the next few weeks will be critical in determining the overall outcome for the Reef this summer, with low to moderate bleaching already reported in many areas of the Marine Park. The Reef Authority will continue to closely monitor forecast conditions and near real-time climate and weather observations, and will collate in-water and aerial surveillance observations and reports for an up-to-date picture of the Reef.

Temperature and rainfall

Sea surface temperatures are generally about 1°C warmer than average for this time of year in the far northern and southern parts of the Reef, while temperatures range up to 2°C above average for the central parts of the Reef.

Significant heat stress has accumulated in some parts of the Far North, and between Townsville and Rockhampton, with the greatest heat stress impacting around the Townsville region. The Bureau of Meteorology is forecasting sea surface temperatures to remain above average throughout most of the marine park in the coming weeks.

Reef health

Recent in-water observations are reporting low to moderate severity coral bleaching across multiple regions of the Marine Park. This is consistent with the patterns of heat stress experienced on the Reef this summer, particularly between Cairns and Mackay. Corals in these areas remain vulnerable to the return of warmer conditions.

Reef management

The Reef Authority is preparing for aerial spot checks of coral health around parts of the Far North and Mackay regions. Our COTS Control Program, along with our partners at the Great Barrier Reef Foundation and the Reef and Rainforest Research Centre, are increasing COTS surveillance and culling capacity between Cairns and Mackay.

Management actions such as controlling the coral-eating predator and enforcing compliance on the water to deter illegal fishing, help protect the Reef and aid recovery from weather events. You can do your bit to help by following zoning rules when out in the Marine Park, and reporting sightings of what is going on across the Reef through the Eye on the Reef app.

Reef Health update – 25 February 2022

Continued milder conditions through the latter half of February have kept sea surface temperatures about average across most of the Marine Park. Meanwhile, monsoonal conditions are expected to develop around northern Australia this week, with multiple tropical lows forecast to form in waters off Australia's north coast. These conditions over the next few weeks will be critical in determining the overall outcome for the Reef this summer.

The Reef Authority is closely monitoring forecast conditions and near real-time climate and weather observations, as well as collating in-water and aerial surveillance observations and reports for an up-to-date picture of the Reef. We are working closely with our Reef Joint Field Management Program partners Queensland Parks and Wildlife Service, AIMS, JCU and other science partners, Traditional Owners, the Crown-of-thorns starfish (COTS) Control Program and marine park industries to understand Reef health.

Temperature and rainfall

Sea surface temperatures have remained near average across the Marine Park over the past week, with temperatures in the northern region slightly above average, and those in the southern region slightly below. The Bureau of Meteorology is forecasting sea surface temperatures will remain near average across the Marine Park into early March.

Reef health

Recent aerial and in-water reports confirm mild to moderate coral bleaching is happening in multiple regions around the Reef, particularly between Cairns and Mackay. This is consistent with the patterns of heat stress experienced on the Reef this summer. Corals in these areas remain vulnerable should we see a return to warmer conditions.

Reef management

The Reef Authority is prioritising areas in the Far Northern Management Area for further surveillance. Our COTS Control Program, along with our partners at the Great Barrier Reef Foundation and the Reef and Rainforest Research Centre, are increasing COTS surveillance and culling capacity around the Cairns, Townsville and Mackay regions.

Management actions such as controlling the coral-eating predator and enforcing compliance on the water to deter illegal fishing, help protect the Reef and aid recovery from weather events. Remember, you can do your bit to help by following zoning rules when out in the Marine Park and reporting sightings of what is going on across the Reef through the Eye on the Reef app.

Reef Health update – 18 February 2022

The Reef Authority is closely monitoring forecast conditions and near real-time climate and weather observations, as well as collating in-water and aerial surveillance observations and reports for an up-to-date picture of Reef health. Over the past few weeks, persistent cloud cover and rainfall have cooled the Marine Park. This more favourable weather has led to a slowdown in heat stress accumulation across the Reef. The milder conditions are expected to persist for the rest of the month which will moderate the impact of thermal stress on the Reef. However, we will be keeping a close eye on conditions, particularly if heat stress builds further as we head into March.

Temperature and rainfall

2021 was the warmest La Niña year on record in Australia, but while December 2021 was the hottest December recorded on the Reef, sea surface temperatures in January were only marginally above average (+0.12°C). Sea surface temperatures were about average across the Marine Park for the first half of February. The Bureau of Meteorology indicates that these temperatures will remain average to below average for the rest of the month, except for some areas in the Far North.

Reef health

Recent aerial and in-water reports confirm mild to moderate coral bleaching is happening at a regional scale, particularly around the central parts of the Great Barrier Reef, which have experienced the greatest heat stress this summer. Corals in these areas remain vulnerable should we see a return to warmer conditions.

Reef management

Our Marine Monitoring Program partners are currently surveying the Princess Charlotte Bay area after flooding of the Normanby River and subsequent flood plumes. Our crown-of-thorns starfish control program is continuing its surveillance and culling operations around the Cairns, Townsville and Mackay regions. Remember, you can do your bit to help by following zoning rules when out in the Marine Park and reporting sightings of what is going on across the Reef through the Eye on the Reef app.

Reef Health update – 11 February 2022

Extensive cloud cover and heavy rainfall in the past few weeks have cooled Reef waters, bringing some much-needed relief, with sea surface temperatures across much of the Marine Park just below average for this time of year. If these milder conditions persist, the impact of this summer’s thermal stress may remain as low to moderate. However, we will be keeping an eye on conditions, particularly if heat stress builds further through February.

Temperature and rainfall

The Bureau of Meteorology forecast is for average or slightly warmer than average sea surface temperatures for the rest of February. The National Oceanic and Atmospheric Administration (NOAA) has revised its outlook in the past week, forecasting less heat stress accumulation this summer, with the peak expected in mid-to-late March. Tropical cyclone activity has been subdued, with only four cyclones recorded so far this summer around Australia, compared to the long-term average of 9 to 11. However, cyclone activity generally peaks between February and March.

Reef health

Since January, areas of low-impact bleaching have been observed across the Marine Park, but no coral mortality has been reported. Aerial and in-water reports confirm low to moderate severity coral bleaching at a regional scale in the central Reef. Recent aerial and in-water surveys around the Townsville region reported some level of bleaching on all 41 reefs observed.

Reef management

The Reef Authority and its partners from the Australian Institute of Marine Science and the Queensland Parks and Wildlife Service have increased its capacity to conduct whole-of-Reef aerial surveys.

Our Field Operations Team incorporates flyovers of various reefs during their activities for extra observations while crown-of-thorns starfish control vessels continue surveillance monitoring and culling operations in the Cairns ─ Cooktown, Townsville ─ Whitsunday and Mackay ─ Capricorn management areas. Remember, you can do your bit to help by following zoning rules when out in the Marine Park and reporting sightings of what is going on across the Reef through the Eye on the Reef app.

Reef Health update – 4 February 2022

The Reef Authority is closely monitoring forecast conditions and near real-time climate and weather observations, as well as collating in-water and aerial surveillance observations and reports for an up-to-date picture of Reef health. Sea surface temperatures across the Reef remain up to 1 °C above average, with some reports of minor to moderate bleaching. The Bureau of Meteorology forecasts for increased rain and monsoonal activity over the last week occurred, with much of the Reef under cloud cover with moderate to heavy rainfall in many areas. This may have provided some cooling benefits to the reef.

Temperature and rainfall

The Bureau of Meteorology’s forecast for the coming month is for sea surface temperatures to remain around 1 °C warmer than the long-term average across the Marine Park. The National Oceanic and Atmospheric Association (NOAA) has placed some areas between Townsville and Mackay and in the far north of the Marine Park on bleaching alert. The remainder of the Marine Park is now predominantly on bleaching watch, with some areas on bleaching warning.

Reef health

There have been several reports of minor bleaching from different parts of the Marine Park. Aerial observations from mid-shelf reefs between Townsville and Port Douglas show some areas of minor to moderate bleaching.

Reef management

The Reef Authority is working closely with its partners to monitor the situation on the Reef. Additional in-water and aerial surveys will occur, and our Field Operations Team has been incorporating flyovers of various reefs during their activities for extra observations. Work is continuing to protect the Reef through a range of management actions, including controlling the coral-eating crown-of-thorns starfish and the summer compliance campaign to deter illegal fishing. You can do your bit to help by following zoning rules when out in Marine Park waters and reporting sightings of what is going on across the Reef through our Eye on the Reef app.

Reef health update - 28 January 2022

The Reef Authority is closely monitoring forecast conditions and near real-time climate and weather observations, as well as collating in-water observations and reports for an up-to-date picture of Reef health. Forecasts from the Bureau of Meteorology and the National Oceanic and Atmospheric Administration (NOAA) are still for warmer than average waters for the end of January and into February, with some level of bleaching expected. This is balanced by very welcome forecasts of strengthening monsoonal activity and widespread rain over many parts of northern Australia in the coming weeks. Ultimately, such regional weather systems will be key to determining the overall outcomes for the Reef this summer.

Temperature and rainfall

Cloud cover during the week has limited data collection, however, where data could be collected, it indicated sea surface temperatures of up to more than 1 °C above average. The Bureau of Meteorology’s forecast for the coming fortnight is for sea surface temperatures to remain, on average, around 1 °C warmer than usual across the Marine Park.

With warmer than average temperatures since the start of summer, the Marine Park has been accumulating thermal stress, elevating the risk of coral bleaching. Fortunately, the recently developed monsoon trough is expected to deepen and become more active, bringing widespread rain and some cooling relief to the Reef. There are indications that several tropical lows may also develop in the next fortnight.

Reef health

The Bureau of Meteorology has confirmed December 2021 as the hottest December on the Reef since records began. Subsequently, there have been reports of minor bleaching from different parts of the Marine Park; however, these remain low impact at this point. We are watching conditions closely, recognising the accumulated heat in the system.

Reef management

The Reef Authority is working closely with its partners to monitor the situation on the Reef. In water, surveys continue to be monitored along with observation reports from various sources. Work is continuing to protect the Reef through a range of management actions, including controlling the coral-eating crown-of-thorns starfish and the successful summer compliance campaign to deter illegal fishing. You can do your bit to help by following zoning rules when out in Marine Park waters and reporting sightings of what is going on across the Reef through our Eye on the Reef app.

Reef health update - 21 January 2022

The Reef Authority is closely monitoring forecast conditions and near real-time climate and weather observations, as well as collating in-water observations and reports to build a current picture of Reef health. Forecasts from the Bureau of Meteorology and the National Oceanic and Atmospheric Administration (NOAA) indicate the Reef will remain hotter than average across the Marine Park for the remainder of January and into February, with further bleaching expected. A La Niña weather pattern is established, though ultimately, regional weather conditions, such as tropical storms and cyclones, over the next few weeks will be critical in determining overall outcomes for the Reef this summer.

Temperature and rainfall

Sea surface temperatures across most of the Reef have varied from just below average to above average during the week. For much of the week, many areas had sea surface temperatures that were on average 1 °C hotter than the long-term average. There are areas that have been exposed to higher sea surface temperatures, particularly inshore areas between Townsville to Mackay.

With higher than average sea surface temperatures since the start of December, the Marine Park has been accumulating thermal stress, elevating the risk of coral bleaching. The inner Townsville ─ Whitsunday, Mackay ─ Capricorn and Far Northern regions have the highest heat stress accumulation.

Reef health

There have been several reports of minor bleaching in the Cairns ─ Cooktown, inner Townsville─ Whitsunday and Mackay ─ Capricorn regions since the start of the year. Reports of bleaching are expected, given the sea surface temperatures that have been observed.

Reef management

The Reef Authority is working closely with its partners to monitor the situation, using the results of in-water and aerial observations and the Eye on the Reef app. Work is continuing to protect the Reef through a range of management actions, including controlling the coral-eating crown-of-thorns starfish and the summer compliance campaign to deter illegal fishing. You can help by following the zoning rules in Marine Park waters and reporting sightings through our Eye on the Reef app.

Reef health update - 14 January 2022

Summary

The Reef Authority uses all available information to inform its situational awareness of the Reef during summer. Forecasts from the Bureau of Meteorology and the National Oceanic and Atmospheric Administration (NOAA) indicate the Reef will remain hotter than average across the Marine Park for the whole of January and into February, with some bleaching expected during the summer months. A La Niña weather pattern is established, though ultimately, regional weather conditions, such as tropical storms and cyclones, over the next few weeks will play a key role in determining overall outcomes for the Reef this summer.

Temperature and rainfall

As at 12 January, sea surface temperatures are still above average across the Marine Park, but are somewhat cooler than last week. Most of the Marine Park is generally 0.5 to 1 °C above average, but as high as 1.5 °C above average in parts of the central region, particularly near Townsville. However, areas near Cape Melville in the north and the southernmost part of the Marine Park are at or below average.

Tropical Cyclone Tiffany passed through the Far Northern region on 10 January as Category 2. Some cooling of sea surface temperatures were observed in the cyclone’s wake. However, the number of days since there was data available for the inshore northern region ranges from 10─17 days due to persistent high cloud cover, which affects the accuracy of real-time data. With higher than average sea surface temperatures since the start of December, the Marine Park has been accumulating thermal stress, which elevates the risk of coral bleaching. The inner Townsville ─ Whitsunday, Mackay ─ Capricorn and Far Northern regions have the highest heat stress accumulation. Forecast monsoonal activity may bring cooler conditions.

Reef health

There are only a few reports of isolated low-level coral bleaching, disease, and damage across the Reef's Far Northern, Northern, Central and Southern areas. Low-level bleaching reports are expected, given the sea surface temperatures that have been observed.

Reef management

The Authority is working with its partners to protect the Reef through a range of management actions, including controlling the coral-eating crown-of-thorns starfish and the summer compliance campaign to deter illegal fishing. You can help by following the zoning rules when out in Marine Park waters and downloading our Eye on the Reef app to report sightings.

Reef health update - 7 January 2022

Summary

The Reef Authority uses all available information to inform its situational awareness of the Reef during summer. Forecasts from the Bureau of Meteorology and the National Oceanic and Atmospheric Administration (NOAA) indicate the Reef will remain hotter than average across the Marine Park for the whole of January and into February, with bleaching expected at some scale during the summer months. A La Niña weather pattern is established, though ultimately, regional weather conditions, such as tropical storms and cyclones, over the next few weeks will play a key role in determining overall outcomes for the Reef this summer.

Temperature and rainfall

Over the Christmas period, sea surface temperatures were generally up to 1.5°C above average for this time of year throughout most of the Marine Park. However, recent rainfall and cloud cover have resulted in some pockets of cooler water in the southernmost part of the Reef, with temperatures at or slightly below average.

With higher than average sea surface temperatures since the start of December, the Marine Park has been accumulating thermal stress, which elevates the risk of coral bleaching. Bureau of Meteorology modelling indicates a high probability of sea surface temperatures exceeding the threshold for a marine heatwave in January.

Ex-Tropical cyclone Seth, now a tropical low, is moving North-North West and continues to impact the southernmost part of the Marine Park with unusually high tides. Forecasts show the monsoon trough may be reinvigorated northeast of Australia towards the end of the week, with a new tropical low likely to form off the far north Queensland coast on the weekend. Monsoonal activity may bring cooler conditions.

Reef health

There are only isolated reports of low-level coral bleaching, disease, and damage across the Reef's Far Northern, Northern, and Central areas. Low-level bleaching reports are expected, given the sea surface temperatures that have been observed.

Reef management

Reef health update - 24 December 2021

Summary

The Reef Authority is using all available information to inform its situational awareness of the Reef during summer. Forecasts from the Bureau of Meteorology and the National Oceanic and Atmospheric Administration (NOAA) indicate the Reef will remain hotter than average across the Marine Park for the remainder of December and into January, with bleaching expected at some scale during the summer months.

A La Niña weather pattern is established, though ultimately regional weather conditions such as cyclones over the next few weeks will play a key role in determining overall outcomes for the Reef this summer. The Authority is also continuing to work with its partners to protect the Reef through a range of management actions, including controlling the coral-eating crown-of-thorns starfish and the summer compliance campaign to deter illegal fishing.

Temperature and rainfall

The Marine Park has been experiencing 1 Degree Heating Days* (DHD) on average every day since the beginning of December, with an accumulation of 20 to 30 DHDs of thermal stress.

The trend in increased sea surface temperatures has continued from last week with temperatures up to 2°C above average throughout the Marine Park. Bureau of Meteorology modelling indicates a high probability of sea surface temperatures exceeding the threshold for a marine heatwave in January.

The La Niña weather pattern is still underway and the Madden–Julian Oscillation (MJO) remains in the western Pacific. This will enhance cloud cover and rainfall across northern Australia and contribute to the development of the Australian monsoon.

Reef health

There are only isolated reports of low-level coral bleaching, disease and damage in the outer Far Northern, Cairns/Cooktown, Townsville/Whitsundays and inner Mackay/Capricorn management areas. No current in-water survey information from the Eye on the Reef network or Australian Institute Marine Science is available for the inner Far Northern and outer Mackay/Capricorn management areas.

Reef management

The Reef Joint Field Management Program is continuing its routine compliance surveillance flights in the Cairns/Cooktown and Townsville/Whitsunday management area, with no bleaching observed for early December. The Reef Authority has increased its contact with all in-water survey teams for more frequent monitoring for coral bleaching. The third quarter report for the Crown-of-the-Thorns control program is available here.

*An estimate of thermal stress of corals. It represents the accumulation of thermal stress over the summer (1 December to 31 March). One DHD is calculated when temperature readings are above the monthly long-term average temperature for a given location.

Summary

The Reef Authority is using all available information to inform its situational awareness of the Reef during summer. Forecasts from the Bureau of Meteorology (BOM) and the National Oceanic and Atmospheric Administration (NOAA) indicate the Reef will remain hotter than average across the Marine Park for the remainder of December and into January, with bleaching expected at some scale during the summer months.

A La Niña weather pattern is established, though ultimately, local weather patterns will determine the impact on Reef health during the summer. The Reef Authority is continuing to work with its partners to protect the Reef through a range of management actions, including controlling the coral-eating crown-of-thorns starfish and the summer compliance campaign to deter illegal fishing.

Temperature and rainfall

Current sea surface temperatures are still above average throughout the Marine Park, especially in the Far North. BOM indicates that sea surface temperatures are likely to be 0.6-1.5°C above average throughout the Marine Park for the rest of December, with the outer Cairns–Cooktown management area up to 2°C above average.

There are up to 20 degree heating days* (DHD) of accumulated heat throughout the Marine Park, with some isolated areas recording up to 30 DHD. Further heat stress accumulation is forecast until at least the end of January, though this will depend on events such as cyclones which can act to cool down water temperatures. The monsoon is unlikely to develop over Australia this coming week; therefore, it is unlikely that rain and cloud cover will provide cooling benefits for the Reef in the short term.

Reef health

As of mid-December, there are still only isolated reports of low-level coral bleaching, disease and damage in the Cairns–Cooktown, Townsville–Whitsundays and inner Mackay–Capricorn management areas. No current in-water survey information from the Eye on the Reef network or AIMS is available for the Far Northern and outer Mackay/Capricorn management areas.

Reef management

Reef health update - 17 December 2021

Summary

Temperature and rainfall

Reef health

Reef management

In early December, the Reef Joint Field Management Program’s routine aerial surveillance of the Cairns–Cooktown and Townsville–Whitsunday management areas found no evidence of bleaching. The Reef Authority has increased its contact with all in-water survey teams for more frequent monitoring for coral bleaching.
*An estimate of thermal stress of corals. It represents the accumulation of thermal stress over the summer (1 December to 31 March). One DHD is calculated when temperature readings are above the monthly long-term average temperature for a given location.

Reef health update - 9 December 2021

Temperature and rainfall

November 2021 was the seventh wettest November on record; however, salinity conditions remain in the normal range across the Marine Park.

The Bureau of Meteorology indicates sea surface temperatures are likely to be 1-2°C above average throughout the Marine Park in December, with the northern half of the park experiencing the highest anomalies.

The current La Niña event is firmly established in the tropical Pacific. The weather pattern is expected to continue until late summer or early autumn 2022.

The National Oceanic and Atmospheric Administration (NOAA) has indicated there is a bleaching warning throughout most of the Far Northern region and a bleaching watch for the rest of the Marine Park, except for the outer Townsville-Whitsundays, Capricorn Bunker group and outer Mackay-Capricorn region which have no bleaching stress. The Northern Territory is on bleaching warning, and the Gulf of Carpentaria and Coral Sea Islands are on Bleaching Watch.

Reef health

There are only isolated reports of low-level coral bleaching, disease and damage in each of the Cairns-Cooktown, Townsville-Whitsundays and Mackay-Capricorn regions. James Cook University researchers have indicated there was no bleaching in Princess Charlotte Bay or the Cape Grenville area as of early December. Coral spawning happened on the Reef during the last weeks of November, with anecdotal evidence from researchers and tourism operators of a particularly good event.

Reef management

The Reef Joint Field Management Program has commenced collecting supplementary observations of the presence or absence of coral bleaching during routine compliance surveillance flights in the Marine Park. The Reef Authority will increase contact with all in-water survey teams to obtain observations around bleaching more frequently.

Keeping an eye on the Great Barrier Reef

With a La Niña now confirmed for the tropical Pacific, the outlook for the health of the Great Barrier Reef depends greatly on local weather conditions over the upcoming summer.

The Great Barrier Reef Marine Park Authority recently convened a workshop where experts met to review modelling and consider risks to the Reef over the summer, including the potential for thermal stress, rainfall and floods, cyclones and storms, outbreaks of crown-of-thorns starfish and coral disease.

The workshop looked at predictions by the Australian Bureau of Meteorology and the United States National Oceanic and Atmospheric Administration, as well as results from the Australian Institute of Marine Science’s Long-Term Monitoring Program and other available information.

Based on several models presented, the summer outlook for the Reef was still uncertain at this point.

Key findings from the workshop: It is difficult to confidently predict peak summer conditions months in advance, as many weather influences can interact and change throughout summer.
It is encouraging to see the advancement in technology, including marine heatwave forecasting.
The current La Niña conditions mean an increased chance of above-average rainfall, more tropical cyclones and lows, and associated flooding.
Forecasts from the Bureau of Meteorology and the US National Oceanic and Atmospheric both indicate higher than average sea temperatures through December 2021 and January 2022.
Regional and local weather conditions will influence temperatures across the Reef, whether thermal stress develops, or if cooling weather conditions prevail.
The current crown-of-thorns starfish outbreak remains most severe on reefs in the central and southern regions of the Marine Park.
Recent evidence confirms an increasing abundance of adult and juvenile crown-of-thorns starfish on several northern region reefs between Cairns and Lizard Island; this indicates the emergence of a new ‘primary’ outbreak of crown-of-thorns starfish.
The Reef Authority is working with crown-of-thorns stars program partners and operators of the existing five control vessels to maximise their cull efforts in light of this new information.
Some encouraging news was the Australian Institute of Marine Science’s Long-term Monitoring Program’s report of coral recovery on many reefs surveyed between August 2020 and April 2021 — demonstrating the Reef is in a recovery window and pointing to the resilience of the Reef ecosystem.

Temperature and rainfall

As of the end of September, sea surface temperatures were generally average to slightly above average throughout the Marine Park. Northern Australia’s wet season began on 1 October 2021. Australia’s Bureau of Meteorology is forecasting warmer and wetter than average air temperatures between November and January.

Sea surface temperatures are likely to be above average throughout the Marine Park in November. The National Oceanic and Atmospheric Administration indicate the Marine Park is currently under no stress in terms of coral bleaching, and that is likely to remain to least mid-November. For the Eastern Australian region, there is a 66 per cent chance this region will receive an above-average number of cyclones this season.

Reef health

Together, the Australian Institute of Marine Science Long-term Monitoring Program and Marine Monitoring Program are developing an updated Reef Monitoring web-based reporting platform. It provides easier access to more up-to-date information on reef health on the Great Barrier Reef.

Reef management

The most crown-of-thorns starfish dashboard contains up-to-date information on control efforts. In September, the control program found starfish feeding scars at reefs in the Cairns to Cooktown area and ongoing starfish activity in the inner and outer Mackay to Capricorn regions. Culling took place in a number of locations throughout Marine Park.

Monthly Reef health update - August 2021

Temperature and rainfall

As of the end of August, sea surface temperatures were generally average to slightly above average throughout the Marine Park. Australia’s Bureau of Meteorology announced a La Niña Watch. The Bureau is forecasting warmer and wetter than average conditions, and above-average sea surface temperatures, throughout the Marine Park between September and November.

The US National Oceanic and Atmospheric Administration indicate the Marine Park is under no stress in coral bleaching, which is expected to remain until at least the end of November.

Reef health

Moderate to high numbers of Drupella snail were reported at some reefs by the Eye on the Reef network.

Reef management

Crown-of-thorns starfish control actions were undertaken at reefs in the Cairns to Cooktown, Townsville to Whitsundays, and Mackay to Capricorn management areas.

Monthly Reef health update - June/July 2021

Temperature and rainfall

As of the end of July, sea surface temperatures were generally average to slightly above average throughout the Marine Park. The US-based National Oceanic and Atmospheric Administration (NOAA) indicated the Marine Park isn’t under stress and is expected to remain that way until at least the end of November. Australia’s Bureau of Meteorology is currently forecasting warmer and wetter than average conditions within the catchment and above-average sea surface temperatures throughout the Marine Park from now to October. An early rainfall onset for the 2021-22 season is likely for most of the Northern Territory and Queensland.

Reef health and management

The Australian Institute of Marine Science released the Long-Term Monitoring Program Annual Summary Report of Coral Reef Condition (2020-2021). Our statement about the report is available on our website.

Marine animal strandings for April to June 2021 show that marine turtle stranding numbers were higher than average, however still below levels of concern. Most turtle strandings (70%) were reported from the Mackay/Capricorn management area, with poor health/disease thought to be the main cause of strandings.

The Eye on the Reef network reported minor coral damage and/or disease a multiple reefs in the outer Cairns/Cooktown and outer Townsville/Whitsunday management areas. Information on our crown-of-thorns control program is available through our reporting dashboards.

Monthly Reef health update - May 2021

Temperature and rainfall

Sea surface temperatures were generally average throughout the Marine Park, apart from the inshore and some mid-shelf areas that were slightly below average. Warmer than average air temperatures are expected between June and August, along with above average sea surface temperatures and above average rainfall.

Reef health and management
In May, the Australian Institute of Marine Science released long-term monitoring survey reports for the Townsville and Cape Upstart sectors. Our Eye on the Reef network observed some minor coral damage and coral disease in the far north and high Drupella snail numbers at some locations.

The Tourism Industry Activation and Reef Protection Initiative increased the delivery of up-to-date information on Reef health status from tourist sites throughout the Marine Park. Information on our crown-of-thorns control program is available through our reporting dashboards.

Weekly Reef health update - 29 April 2021

This week saw the release of the second annual Reef Snapshot, produced by the Great Barrier Reef Marine Park Authority, Australian Institute of Marine Science (AIMS), and CSIRO. The snapshot provides a concise, easy-to-understand summary of how the Reef has fared over the past summer, what this means for coral, and the actions being taken to help coral health. Among the findings from the 2020-21 summer:

There were no prolonged high temperatures or major cyclone disturbances, and many reefs continued their recovery from past impacts.
Water temperatures did not cause as much coral heat stress as in recent years, although all months were warmer than average.
Cyclone Kimi was the only tropical cyclone that tracked across the Reef, and its potential to cause widespread catastrophic damage to reefs was assessed as very low.
While there was some good rainfall in the catchment, flood levels in waterways near the Reef were generally not major or sustained.
Crown-of-thorns starfish remains at an outbreak or potential outbreak level in parts of the Reef's northern, central, and (particularly) southern regions. The Crown-of-thorns Starfish Control Program continues to work in all three regions to cull starfish down to non-outbreak levels.

From here, we will release monthly updates on Reef health until the beginning of the summer 2021-22.

Weekly Reef health update - 15 April 2021

Temperature and rainfall

Sea surface temperatures are currently average to above average, with the warmest temperatures found in inshore and mid-shelf areas and cooler temperatures offshore. Temperatures are below bleaching thresholds.

Rainfall over the next three months is likely to be below average for most of Queensland; however, the fortnight 12 – 25 April may see wetter than average conditions just inland from Queensland’s eastern coast. The Bureau of Meteorology continues to forecast warmer than average conditions in some parts of the catchment and above average sea surface temperatures between May and July, particularly in the Far Northern region and within the Reef’s inshore areas.

Reef management

After the high rainfall and flooding in southern areas of Queensland in recent months, we may see an increase in the numbers of sick, injured, and dead turtles, dugong and inshore dolphins during 2021. Queensland Parks and Wildlife Service rangers conducted 1056 Reef health and impact survey assessments at 170 reef locations in the first quarter of 2021.

Weekly Reef health update — 1 April 2021

Temperature and rainfall

Reef temperatures remain below bleaching thresholds. Sea surface temperatures are mostly average to slightly above average, with the warmest temperatures found in the Cairns–Cooktown region and at inshore and mid-shelf areas in the central and southern areas.

The Bureau of Meteorology moved its ENSO outlook to inactive, indicating an end to the 2020–21 La Nina event. A subtropical low is forecast to develop over the central Coral Sea on Friday or Saturday; however, it is not expected to become a severe tropical storm.

The Bureau of Meteorology continues to forecast warmer than average conditions and above-average sea surface temperatures between April and June, particularly in the northern tropics. Rainfall over the next three months is also likely to be above average for large parts of north-eastern Australia; however, this signal is mostly from April.

Reef management

Great Barrier Reef Marine Park Authority staff joined industry leaders, experts, and Traditional Owners at the International Crown-of-thorns Starfish Forum in Cairns this week to discuss latest research findings and strategies for improved management. Compliance flights conducted between Cooktown and Princess Charlotte Bay (26 to 28 March) observed no signs of coral bleaching on offshore reefs and only low to moderate bleaching on some inshore and mid-shelf reefs.

Monthly Reef health update - March 2021

Weekly Reef health update - 25 February 2021

Temperature and rainfall

The Australian Institute of Marine Science in-water temperature loggers at a subset of reefs across the Marine Park indicate temperatures are currently below bleaching thresholds.

Sea surface temperatures are mostly close to the long-term monthly average. Temperatures are slightly warmer (mostly 0.5 to 1.0°C) in some offshore parts of the central Reef, on scattered areas in the north, and some inshore areas in the far north. Moderate to heavy rainfall occurred in northern Australia over the past week, with the highest weekly rainfall total of 709 mm recorded at Tully Sugar Mill in the central area.

The Bureau of Meteorology is still forecasting warmer and wetter than average conditions across the Marine Park catchment, and above average sea surface temperatures throughout the Marine Park between March and May, particularly in the northern tropics. We continue to receive situational reports on reef health and monitor conditions — as usual, local and regional weather conditions over the next few weeks will play a key role in determining overall outcomes for the Reef this summer.

Reef health and management actions

Marine Monitoring Program water quality teams are out this week conducting routine flood event monitoring in focus areas in Cape York and the Wet Tropics. This week, 17 marine tourism operators along the entire Great Barrier Reef started undertaking reef site monitoring and maintenance. The focus will be on 234 reefs until 30 June 2021.

Crown-of-thorns starfish surveillance and control efforts continue in the Cairns–Cooktown region, Townsville–Whitsundays region, and Mackay–Capricorn region. The Reef Water Quality Report Card 2019 — released last week by the Australian and Queensland Environment Ministers — details progress towards the Reef 2050 Water Quality Improvement Plan targets up to June 2019.

Weekly Reef health update — 18 February 2021

Temperature and rainfall

Sea surface temperatures in the Marine Park are mostly close to the long-term monthly average. It is slightly warmer (mostly 0.5 to 1.0°C) offshore in the central area, in scattered areas in the north, and in some inshore areas in the far north. A monsoon break is developing across northern Australia, with an expected change from widespread rainfall to isolated shower and thunderstorm activity for Australia’s tropics.

As a result, we expect to see below-average rainfall and above-average temperatures persisting in the region for the remainder of February. The Bureau of Meteorology is still forecasting warmer and wetter than average conditions across the catchment and above average sea surface temperatures between March and May, particularly in the northern tropics.

We continue to receive situational reports on Reef health and continue to monitor conditions as the summer unfolds — as usual, local and regional weather conditions over the next few weeks will play a key role in determining overall outcomes for the Reef this summer.

Reef health

Queensland Parks and Wildlife Service rangers surveyed offshore and mid-shelf reefs northeast of Lockhart River–Cape Grenville and found some scattered, low levels of coral bleaching and/or fluorescing. The Australian Institute of Marine Science Long-term Monitoring Program survey reports are now available for the Cairns and Innisfail sectors. We’ve received reports from Lizard Island Research Station of coral bleaching/fluorescing on the reef flat off South Island — currently, there’s no to low mortality.

Reef health update — 11 February 2021

Temperature and rainfall

Cloud cover cleared over most of the far northern Great Barrier Reef during the past week, and we now have a good view of current sea surface temperatures on the Reef. Sea surface temperatures throughout most of the Marine Park are close to the long-term monthly average. The exception is slightly warmer temperatures (0.5 to 1.0°C above average) in some inshore and mid-shelf regions of the Far Northern and Townsville–Whitsunday management areas. The Bureau of Meteorology is still forecasting warmer and wetter than average conditions and above average sea surface temperatures across the Marine Park through to April.

However, due to an expected break in the monsoon over northern Australia, below-average rainfall and above-average temperatures are expected to persist for the rest of February. We continue to monitor conditions closely — as usual, local, and regional weather conditions over the next few weeks will play a key role in determining overall outcomes for the Reef this summer.

Reef health

Queensland Parks and Wildlife Service rangers recently surveyed offshore reefs in the Far Northern management area, with early reports indicating no to low levels of coral bleaching. The Australian Institute of Marine Science Long-term Monitoring Program surveys are underway in the Whitsundays sector, wrapping up on 21 February. Marine Monitoring Program water quality teams are out this week conducting routine sampling in the Burdekin region.

Weekly Reef health update — 4 February 2021

Temperature

Available data indicates temperatures across the Marine Park currently remain below bleaching thresholds. Satellites now have a good view of most of the Great Barrier Reef, except for an area of the far north. We will get a better understanding of current conditions in this region once cloud cover dissipates.

In those areas of the Marine Park where data is available, sea surface temperatures are close to, or slightly below, the long-term monthly average. The Australian Institute of Marine Science in-water temperature loggers at a subset of reefs across the Marine Park indicate sea surface temperatures currently remain below bleaching thresholds. The Bureau of Meteorology is forecasting warmer and wetter than average conditions across the Marine Park catchment, and above average sea surface temperatures across the Marine Park between February and April. We continue to monitor conditions closely — as usual, local, and regional weather conditions over the next few weeks will play a key role in determining overall outcomes for the Reef this summer.

Rainfall

The 2020-21 La Niña event is likely to have peaked, however we may see above-average rainfall across the tropics until early autumn. A tropical low expected to form in the Gulf of Carpentaria later this week may reinvigorate the active monsoon, increasing the likelihood of widespread rainfall across Australia’s tropics over the next fortnight.

Reef health

Results from the Australian Institute of Marine Science Long-term Monitoring Program surveys in the Princess Charlotte Bay and Cape Grenville sectors (30 November – 22 December 2020) are now available. Rangers from the Queensland Parks and Wildlife Service visited the Far Northern management area in mid-to-late January 2021, finding no bleaching at most surveyed reefs and some localised minor bleaching at a few locations.

Weekly Reef health update — 28 January 2021

Temperature

Sea surface temperatures in most inshore areas are either close to, or slightly below, average, except in the far north where it is above average. We will know more about this area when clouds clear. Modelled data showing warmer areas should be interpreted with caution, as cloud cover continues to restrict the ability of satellites to accurately measure sea surface temperatures over the far northern part of the Reef.

We continue to monitor conditions closely — as usual, local and regional weather conditions over the next few weeks will play a key role in determining overall outcomes for the Reef this summer.

Rainfall

Active monsoon conditions continue across northern Australia, with above-average rainfall likely. A tropical low currently over the Cape York Peninsula is expected to track into the Coral Sea this weekend, bringing heavy rainfall and possible flash flooding to parts of the Peninsula today.

There is a moderate chance (20 to 50 per cent) this system will form into a tropical cyclone in the Coral Sea over the weekend or early next week. The Bureau of Meteorology indicates a high likelihood of a tropical cyclone developing over northern Australia waters in the coming week.

Reef health

The Great Barrier Reef Crown-of-thorns control program is helping protect coral cover at locations between Cairns and the Capricorn coast.

Weekly Reef health update - 22 January 2021

Temperature

Like the past two weeks, cloud cover continues to restrict the ability of satellites to accurately measure sea surface temperatures over much of the Reef and modelled data showing warmer areas should be interpreted with caution.

Where observations were possible in recent days, sea surface temperatures remain close to, or below, the long-term monthly average in the south and central Reef and above average in the far northern Reef. Temperatures are currently below bleaching thresholds. We continue to receive situational reports on Reef health, and we will monitor conditions on the Reef as the summer unfolds. As usual, local and regional weather conditions over the next few weeks will play a key role in determining overall outcomes for the Reef this summer.

Rainfall

The current La Niña event has likely now reached its peak, with a gradual easing expected near the end of the first quarter of 2021. We may see above-average rainfall in eastern and northern Australia into early autumn. Ex-tropical cyclone Kimi was the first tropical cyclone to form within the Marine Park during the 2020-2021 season, bringing cloud cover and rainfall to parts of the Reef and tropical north coast.

Reef health

Recent reports made through Eye on the Reef indicate mostly scattered, isolated cases of minor coral bleaching within the Marine Park. The Australian Institute of Marine Science long-term monitoring surveys are currently underway in the Cairns and Innisfail Sectors, with early reports from Cairns indicating only very low-level bleaching observed. The Reef Joint Field Management Program commenced in water observations this week to reefs between Cairns and Raine Island, with reports on observations of Reef Health to follow.

Weekly Reef health update - 15 January 2021

Temperature

Like last week, cloud cover continues to restrict the ability of satellites to accurately measure sea surface temperatures over much of the Reef and modelled data showing warmer areas should be interpreted with caution. Where observations were possible in recent days, sea surface temperature looks close to the long-term monthly average in the south and central parts of the Reef and above average in the far northern section.

We will get a better understanding of current conditions when cloud cover dissipates. The Australian Institute of Marine Science in-water temperature loggers at a subset of reefs across the Reef indicate temperatures currently remain below bleaching thresholds. The Bureau of Meteorology is forecasting warmer and wetter than average conditions, and above average sea surface temperatures across the Marine Park catchment between February and April. As usual, local and regional weather conditions over the next few weeks will play a key role in determining overall outcomes for the Reef this summer.

Rainfall

Most of the central Great Barrier Reef coast and catchment received significant rainfall over the past week, with multiple flood warnings currently still in effect near Tully. Models indicate a monsoon trough may develop across northern Australia in about a week, with widespread rainfall and tropical cyclone development becoming more likely.

Reef health

Monitoring providers continue to be on flood watch with more rains expected, and teams are sampling the routine wet season Tully sites this week. This past week, we’ve received reports of localised coral bleaching from locations in the far north of the Reef. Surveys by the Australian Institute of Marine Science’s Long-Term Monitoring Program are currently underway at reefs in the Cairns and Innisfail Sectors, with updates available shortly. The Reef Joint Field Management Program commences scheduled trips next week to reefs between Cairns and Raine Island, with reports on observations of coral bleaching to follow.

Weekly Reef health update – 7 January 2021

Temperature and rainfall

Recent cloud cover has restricted the ability of satellites to accurately measure sea surface temperatures over the past week. As a result, modelled sea surface temperatures may appear warmer than they are. Data should be interpreted with caution. Where observations have been possible, mainly in the southern Great Barrier Reef, there is an indication of cooling, with sea surface temperatures now closer to the long-term monthly average. We will get a better understanding of current conditions once satellites can again see the Reef.

Most of the northern Great Barrier Reef coast and catchment received significant rainfall over the past week, with the highest totals falling between Cairns and Townsville. Local and regional weather conditions over the next few weeks will play a key role in determining overall outcomes for the Reef this summer.

Cyclones

Ex-tropical cyclone Imogen was the first Australian tropical cyclone of the 2020-2021 season, crossing the Queensland coast near Karumba as a category 1 system and bringing severe thunderstorms and heavy rainfall to the north tropics. There is a low chance of this system reforming into a tropical cyclone in the Coral Sea. There are no current cyclones.

ENSO outlook

The Bureau of Meteorology’s El Niño–Southern Oscillation (ENSO) outlook remains at La Niña, with latest modelling indicating the La Niña event is likely now at its peak. The Bureau forecasts a gradual easing towards neutral values during late summer or early autumn.

Reef health

AIMS’ in-water temperature loggers at a subset of reefs across the Great Barrier Reef indicate that temperatures currently remain under bleaching thresholds. Crown-of-thorns starfish control vessels continue to conduct ongoing surveillance and control in all management regions apart from the Far Northern region. These control efforts are effectively mitigating outbreaks and damage to reef health, across reefs targeted for pest management.

Weekly Reef health update - 24 December 2020

Temperature and rainfall

The Bureau of Meteorology indicates sea surface temperatures throughout the Marine Park have increased slightly over the last week, and are now mostly 1.0-1.5°C above average. The La Niña event continues in the tropical Pacific, and is likely to be approaching its peak strength, with a gradual easing likely during the first quarter of 2021.

Official monsoon onset date was 19 December in Darwin. Typical of La Niña years, this season’s monsoon onset date was earlier than average and comparable to the 2016–17 wet season. The Bureau of Meteorology is forecasting warmer and wetter than average conditions, and above average sea surface temperatures across the Marine Park catchment between January and March. Local and regional weather conditions over the next few weeks will play a key role in determining overall outcomes for the Reef this summer.

Reef health

Despite recent warming on the Reef, reports from in-water surveys including from the Eye on the Reef program indicate only scattered, minor bleaching is present in the Marine Park. Crown-of-thorns starfish outbreaks continue to affect individual reefs in multiple areas of the Marine Park. The most severe impacts are currently occurring on reefs in the Townsville-Whitsunday (offshore) and Mackay-Capricorn (inshore and offshore) management areas.

Reef management actions

The Crown-of-thorns Starfish Control Program continues throughout the Marine Park. In the Cairns-Cooktown region almost 2000 crown-of-thorns starfish have been culled at five reefs in the past month. Queensland Parks and Wildlife Service recently completed a total of 87 Reef health impact surveys and 560 broad-scale manta tows at 21 offshore reefs. Reef locations were chosen to fill knowledge gaps on the extent and severity of outbreaks.

Weekly Reef health update - 21 December 2020

Temperature and rainfall

The Bureau of Meteorology indicates that sea surface temperatures are mostly average throughout the Marine Park, with some warming in offshore regions of the Far Northern and Mackay-Capricorn management areas have warmed over the past week.

In the first half of December, some areas in the Far Northern and Mackay-Capricorn management regions were up to 1.0°C above average.
The current La Niña event continues in the tropical Pacific and is expected to peak at moderate levels in December. It is expected to return to a neutral phase during the late summer or autumn.

This week severe thunderstorms are an elevated risk across the Far North. Current atmospheric conditions are favourable for the redevelopment of a monsoon trough across northern Australia in the coming week. Between January and March, the Bureau is forecasting warmer and wetter than average conditions, and above average sea surface temperatures across the Marine Park catchment.

Weekly Reef health update - 10 December 2020

Temperature and rainfall

The Bureau of Meteorology indicates sea surface temperatures are mostly average throughout the Marine Park. In the second half of November, some parts of the Far Northern and Mackay–Capricorn management areas were up to 1.0°C above average.

The current La Niña event continues in the tropical Pacific and is expected to peak at moderate levels in December. It is expected to return to a neutral phase during the late summer or autumn. Over the next fortnight, a monsoon onset could produce above-average rainfall over northern Australia.

Between December and February, the Bureau is forecasting warmer and wetter than average conditions and above-average sea surface temperatures across the Marine Park catchment. The National Oceanic and Atmospheric Administration (NOAA) indicates the Far Northern region remains on Bleaching Watch, along with the Torres Strait and Gulf of Carpentaria. The Northern Territory is on Bleaching Warning. Most of the Marine Park is forecasted to be on Bleaching Watch by the end of December.

Reef health

Over the last three months, the number of marine strandings within the Marine Park remained consistent. The Southern region recorded higher numbers than the Northern region. The 10-year median for turtle strandings was exceeded for the third consecutive month. However, trends do not currently indicate cause for concern.

Crown-of-thorns starfish

Our latest data is available on our dashboard. Outbreaks continue to impact reef health across all management areas, with the most severe impacts occurring on reefs in the Townsville–Whitsunday (offshore) and Mackay–Capricorn (inshore and offshore) management areas. In the Cairns–Cooktown region, culling is underway at Fitzroy Island, Round-Russel and Eddy reefs. Crown-of-thorns starfish have decreased to ‘No Outbreak’ densities at Fitzroy Island Reef.

In the Townsville–Whitsunday region, culling operations continue at Trunk, John Brewer, Keeper, Davies, and Big Broadhurst reefs. In the Mackay–Capricorn region, culling operations are ongoing at Boult, Fairfax, Fitzroy, Heron, Hoskyn Islands, Lady Elliot Island, Lady Musgrave Island, and Llewellyn reefs.

Monthly Reef health update - November 2020

With summer 2020-21 beginning, this is our last monthly Reef health update — we are resuming our regular updates over the summer.

Temperature and rainfall

This was the second-warmest November on record for Queensland, with below-average rainfall recorded across most of the State. In the second half of the month, sea surface temperatures were slightly above average in most areas, except the Far Northern and Mackay–Capricorn management areas which were up to 1.5°C above the long-term monthly average. The Bureau of Meteorology indicates the current La Niña event will likely persist until February 2021, peaking in December 2020 or January 2021 at moderate to strong levels.

Reef health

Our Eye on the Reef network reported isolated moderate to severe level bleaching at two reefs in the Cairns–Cooktown management area. There are reports of scattered instances of low-level bleaching elsewhere throughout the Marine Park, apart from the Far Northern management area.

The Australian Institute of Marine Science surveys of the Cooktown-Lizard Sector in October and November 2020 showed moderate hard coral cover sector-wide and strong recovery from cumulative disturbances in 2013–2017. There are anecdotal reports of coral recovery at Fitzroy Lagoon.

Crown-of-thorns starfish

Our latest data is available on our dashboard. Outbreaks continue to impact Reef health across all management areas, with the most severe impacts occurring on reefs in the Townsville–Whitsunday (offshore) and Mackay–Capricorn (inshore and offshore) management areas.

Pre-summer workshop

Marine experts met on 25 November 2020 to consider risks to the Reef over the summer, including the potential for thermal stress, rainfall and floods, cyclones and storms, outbreaks of crown-of-thorns starfish and coral disease. The meeting, convened by the Great Barrier Reef Marine Park Authority, looked at multiple lines of evidence to support a summer outlook likely to be influenced by La Niña, pointing to more rainfall and cyclones.

Key findings from the workshop: It is difficult to confidently predict outcomes for peak summer months in advance as many weather influences can interact and change through summer. While La Niña events often mean reduced temperatures, thermal stress is still possible as sea surface temperatures across the whole Reef have gone up due to climate change.

Forecasts from the Bureau of Meteorology and the US National Oceanic and Atmospheric Administration both indicate higher than average sea temperatures through December 2020 and January 2021. The current La Niña conditions also mean an increased chance of above-average rainfall, more tropical cyclones and lows, and associated flooding. Regional and local weather conditions will influence temperatures across the Reef if thermal stress develops, or if cooling weather conditions prevail.
Outbreaks of coral-eating crown-of-thorns starfish remain an ongoing impact, particularly in the central and southern Reef. This reinforces the importance of the control program that protects coral cover. Encouraging was the Australian Institute of Marine Science’s Long-term Monitoring Program’s report of some coral recovery on many reefs surveyed between September 2019 and June 2020 — pointing to the resilience of the Reef ecosystem.

Monthly Reef health update - October 2020

Temperature and rainfall

During the two-week period, October 14 to November 3, sea surface temperature anomalies were mostly average throughout the Great Barrier Reef Marine Park, except between Princess Charlotte Bay and Bowen, with temperatures up to 1.5°C above the long-term monthly average.

La Niña persists

The Bureau of Meteorology indicated the current La Niña event will likely persist until February 2021. Around half of the international climate models surveyed by the Bureau still, predict a strong event.

The United States National Oceanic and Atmospheric Administration (NOAA) indicates thermal stress could develop in the Whitsundays region as early as December.

Reef health

Our Eye on the Reef network reported isolated instances of low severity coral bleaching, damage and disease in the Cairns–Cooktown, Townsville–Whitsunday and Mackay–Capricorn management areas. No current information is available for the Far Northern management area.

The result of AIMS’ long-term monitoring program surveys of the Swains and Capricorn-Bunkers in August/September 2020 is now available on the AIMS website.

Crown-of-thorns starfish

Crown-of-thorns starfish continue to impact reef health across all management areas, with the most severe impacts occurring on reefs in the outer Townsville–Whitsundays and inner and outer Mackay–Capricorn management areas.

Great Barrier Reef Park Marine Authority’s Crown-of-thorns starfish Control Program Quarterly Reports Dashboard is live on our website, with the Q3 2020 report now available.

Control activities in the Cairns/Cooktown region remain underway at Round-Russell Reef. In Townsville–Whitsundays region, cull operations were conducted in October on five reefs; Trunk Reef, John Brewer Reef, Keeper Reef, Davies Reef and Big Broadhurst Reef. In Mackay–Capricorn region, a control vessel is focused on culling efforts on eight reefs.

Monthly Reef health update - September 2020

Temperature and rainfall

In the last two weeks of September, sea surface temperatures throughout the Great Barrier Reef Marine Park were 0.5 - 1.5°C above the long-term monthly average.

La Niña established

The Bureau of Meteorology confirmed a La Niña is now established in the tropical Pacific. All international climate models surveyed by the Bureau predict this event will continue until at least January 2021. La Niña events typically bring more rainfall, cloud cover and tropical cyclones. Around half of the international climate models predict a strong La Niña event, while three of eight models predict a moderate event. Models predict it will likely be stronger than the 2017-18 event but weaker than the 2010-12 event.

Stranded turtles

In August, we saw a significant increase in the number of reports of stranded marine turtles, particularly green turtles. These strandings occurred in the southern Marine Park, with Yeppoon beaches being a hotspot. The cause of the strandings includes boat strike, poor health/disease, entanglement and unknown causes. The number of strandings was below thresholds for concern — however, the numbers were higher than generally expected for August. The Queensland Parks and Wildlife Service (QPWS) will continue to monitor the situation closely.

Coral bleaching and disease

Our Eye on the Reef network reported isolated instances of low severity coral bleaching and damage in all management areas. Isolated instances of low severity coral disease were reported from all areas except the Far Northern management area.

Crown-of-thorns starfish

Crown-of-thorns starfish outbreaks continue to impact reef health across all management areas. Control vessels continue to conduct ongoing control and surveillance activities. These control efforts are effectively mitigating outbreaks and the damage to reef health.

The Marine Park Authority has developed an interactive Crown-of-thorns starfish Control Program Quarterly Reports Dashboard, which shows the progress of the control program in both the current quarter and throughout the program to date (since its expansion in November 2018).

Tourism Industry Activation and Reef Protection Initiative

The Australian Government established a $1 billion COVID-19 Relief and Recovery Fund to support regions, communities and industry sectors severely affected by the coronavirus crisis. This initiative will provide some business continuity within the Reef tourism industry through engaging marine tourism operators to undertake in-water conservation and monitoring activities.

One of the key activities delivered will be the collection of important data from in-water surveys through the Great Barrier Reef Marine Park Authority’s Eye on the Reef system, improving knowledge and understanding of Reef health, including impacts and recovery.

Monthly Reef health update - August 2020

Temperature and rainfall

In the last two weeks of August, sea surface temperatures throughout the Marine Park were 0.5 to 1.5°C above the long-term monthly average. Winter 2020 was warmer than average for Queensland, being the seventh warmest on record. Rainfall was above average in Queensland’s west and north.

The Bureau of Meteorology moved from a La Niña WATCH to La Niña ALERT. This means there is a 70 per cent chance of a La Niña developing in 2020, including the possibility that it may develop in spring. For the Great Barrier Reef region, La Niña conditions typically result in early wet season onset, more tropical cyclones and an increased chance of widespread flooding. Spring 2020 is forecast to be warmer and wetter than average across the region.

Reef health

The Eye on the Reef network reported isolated instances of low severity coral bleaching, disease and damage in the Cairns/Cooktown, Townsville/Whitsunday and Mackay/Capricorn management areas. No information is available from the Far Northern management area. The Australian Institute of Marine Science (AIMS) Long-term Monitoring Program (LTMP) released their 2019/2020 annual summary for the Great Barrier Reef.

Crown-of-thorns starfish

Outbreaks of the coral-eating crown-of-thorns starfish continue to impact reef health across all management regions, with the most severe impacts occurring on reefs in the outer Townsville/Whitsundays and inner and outer Mackay/Capricorn management regions. In the Cairns/Cooktown region, the crown-of-thorns starfish control program has successfully culled crown-of-thorns starfish down to ecologically sustainable levels at five of the six reefs targeted by the program. In the Townsville/Whitsundays region, culling is ongoing at two reefs. In the Mackay/Capricorn region, culling activities are currently focusing on the Capricorn Bunker Group.

Monthly Reef health update - July 2020

Temperature and rainfall

Sea surface temperatures throughout the Marine Park remained mostly average in July. The Bureau of Meteorology forecasts a 50 per cent chance of a La Niña developing in spring. August to October is predicted to be warmer and wetter than average for Queensland.

In-water surveys and reports

Survey numbers were low due to COVID-19 travel restrictions. As part of the Marine Monitoring Program, the Australian Institute of Marine Science surveyed the Wet Tropics, from Townsville to Cooktown, and found overall coral health was good. The surveys found very few colonies showed signs of bleaching, and there was little evidence of any coral mortality from the 2020 mass bleaching event.

The Eye on the Reef network has reported isolated instances of low severity coral bleaching, disease and damage in the Cairns/Cooktown, Townsville/Whitsunday and Mackay/Capricorn management areas. No information is available from the Far Northern management area. There are positive anecdotal reports from the Eye on the Reef network in the Cairns/Cooktown region and the Mackay/Capricorn region.

Crown-of-thorns starfish

Crown-of-thorns starfish outbreaks continue to impact Reef health across all management regions. The most severe impacts are on reefs in the outer Townsville/Whitsundays and inner and outer Mackay/Capricorn management regions. Control boats visited eight reefs in the Cairns/Cooktown region, with below outbreak numbers detected. At seven of the eight reefs visited, crown-of-thorns starfish were pro-actively culled to ecologically sustainable numbers.

Humpback whales

Humpback whales continue to be a key sighting in the Marine Park. Whales are making their annual migration from Antarctica to the warmer waters of the Great Barrier Reef to court, mate, give birth or rear their calves.

Monthly Reef health update - June 2020

Crown-of-thorns starfish

Crown-of-thorns starfish outbreaks continue to impact Reef health across the Marine Park, most severely on reefs offshore in the central region and the inshore and offshore southern regions. The crown-of-thorns starfish control program vessels continue to conduct ongoing surveillance and control in the northern, central and southern Marine Park.

Recent targeted culling effort has been focused on high-value tourism sites. Most recently, one of the control vessels surveyed five reefs in the Lizard Island region. While most of the reefs had low densities or no crown-of-thorns starfish, one reef was found to have established outbreaks. Following this detection, the control vessel culled all sites on the reef to bring crown-of-thorns starfish numbers down to ecologically sustainable levels for coral growth and recovery.

Temperature and rainfall

Sea surface temperatures throughout the Marine Park were generally average at the end of June. The Bureau of Meteorology is forecasting July to be drier than average for parts of Queensland’s far northern tropics. Warmer and wetter than average conditions are predicted for much of Queensland through to September. The Bureau’s ENSO outlook status has been shifted to La Niña WATCH. La Niña events typically bring above-average spring rainfall in the Great Barrier Reef region.

Surveys conducted near Townsville

COVID-19 travel restrictions limited the amount of in-water surveys conducted this year. However, with restrictions easing, surveys on reefs offshore from Townsville were conducted by the Australian Institute of Marine Science. Preliminary observations show some levels of bleaching are still evident on most reefs in this region. Most observations show bleaching on less than five per cent of colonies but up to 20 per cent in some parts. Bleaching was mainly observed on the flat, crest and upper slope.

While there was evidence of some mortality due to bleaching, no significant widespread mortality was observed. There were also low levels of crown-of-thorn starfish observed on most reefs.

Reports through Eye on the Reef

Reports of coral bleaching, disease and damage made through the Eye on the Reef program continue to observe only scattered, low-level impacts during the month of June, however numbers of reports are currently limited. Remember to download our free Eye on the Reef app to record Reef health, animal sightings or incidents if you're visiting the Great Barrier Reef.

Monthly Reef health update - May 2020

Sea surface temperatures

Sea surfaces temperatures throughout the Marine Park were generally average at the end of May. Inshore regions in central and southern areas were up to 2°C cooler.

Reef health

There continues to be a limited amount of post-bleaching surveys being conducted due to COVID-19 travel restrictions. The Eye on the Reef program continue to receive reports that coral disease is scattered with low-level impacts. There are anecdotal reports of coral recovery at John Brewer Reef, Moore Reef, Lady Elliot, Heron Island and Low Isles.

Coral recovery at Keppel Islands

As part of the Great Barrier Reef Marine Park Authority’s Marine Monitoring Program, the Australian Institute of Marine Science conducted surveys in the Keppel Islands in early May. This region had a high level of bleaching during the 2019-2020 summer bleaching event. Reports from these surveys show patchy coral mortality and low levels of coral disease. However, on average 15% of coral cover remains bleached white. This suggests limited recovery and the potential for further decline in coral cover.

Humpback whales

We’ve received multiple reports through our Eye on the Reef sightings network of humpback whales in the Whitsundays and Townsville areas. From May to September, whales make the trek from Antarctica to the Reef’s warmer waters to court, mate, give birth or rear their calves.

Monthly Reef health update - April 2020

We acknowledge the significant impact COVID-19 has on Reef-related industries and communities and welcome additional support announced by the Australian Government for tourism and regional economies. We are continuing to provide updates on Reef health during this time – updates will be monthly until the start of the 2020-21 summer.

2019-20 wet season wrap-up

Northern Australia’s 2019-20 wet season was the driest since 2004-05 and the second well-below average wet season in a row, according to the Bureau of Meteorology. Tropical cyclone numbers were also well below the long-term average.

Temperature and rainfall outlook

Sea surface temperatures throughout the Marine Park were generally average at the end of April. The Bureau of Meteorology is forecasting warmer and wetter than average conditions for Queensland through to August.

Reef snapshot: summer 2019-2020

In April 2020, we released the first Reef snapshot with the Australian Institute of Marine Science and CSIRO. It is a concise, easy-to-understand summary of how the Reef has fared over the past summer, what this means for coral and the actions being taken to help coral health. The snapshot found:

Northern (Cape York – Lizard Island): Moderate hard coral cover and low levels of crown-of-thorns starfish (COTS). Bleaching is moderate to severe on mid-shelf and inshore reefs, with little to no bleaching on outer-shelf reefs.

Central (Lizard Island – Whitsundays): Moderate hard coral cover in Cairns and low in Innisfail overall, with no COTS observed. Moderate bleaching levels near Cairns, but generally more widespread and severe bleaching on mid-shelf reefs further south (except the Whitsundays).

Southern (Whitsundays – Cap-Bunkers/Swains): Hard coral cover and active COTS in the Pompeys, high levels of hard coral cover in the Cap-Bunkers and moderate levels of hard coral cover and COTS outbreaks in the Swains. Variable bleaching observed overall, with two-thirds of reefs moderately to severely bleached in the Pompeys and Swains.

Coral bleaching recovery

Surveys of post-bleaching recovery and mortality have not been conducted due to COVID-19 social distancing and travel restrictions. As a result, we are mostly reliant on reports from locals and tourism operators. Magnetic Island is showing signs of recovery from the recent mass bleaching event in the 2019-20 summer. Reports show corals and giant clams are regaining some of their function/colour. Footage from four reefs offshore from Cairns shows healthy coral with small amounts of bleaching. Early reports from the Marine Monitoring Program show encouraging signs of recovery on inshore sites in the Burdekin and Keppels Islands. Observations of coral disease submitted through the Eye on the Reef program indicated scattered low-level impacts.

Crown-of-thorns starfish management

The crown-of-thorns starfish control vessels commenced culling at four reefs in the Capricorn-Bunker Group which are currently in active outbreak status.

Rare sighting reported on Eye on the Reef

Footage of a rare and endangered ornate eagle ray was sighted near Lady Elliot Island. There are only about 50 sightings recorded for this species world-wide.

Weekly Reef health update — 02 April 2020

Sea surface temperatures

As of 31 March 2020, sea surface temperatures (SSTs) across the Great Barrier Reef were near average and well below the temperatures that caused mass coral bleaching this summer. Although temperatures decreased, the effects of prolonged thermal stress are still being observed across the Marine Park and it will take time for bleached corals to recover and regain their colour and health.

Reef-wide aerial surveys to determine the extent and severity of coral bleaching across the Reef concluded on Friday 27 March 2020. The Australian Research Council Centre of Excellence for Coral Reef Studies at James Cook University will analyse the aerial survey data in the coming weeks and release the information. The aerial surveys indicate variability at a whole of Reef scale, which will only be shown once a full analysis and mapping occurs. Some initial observations from the aerial surveys:

Widespread moderate to severe bleaching across much of the Reef Severe bleaching was more widespread than in previous bleaching events.
Areas, mostly well offshore, had no or low level bleaching.
Some areas have reefs with a mix of negligible, moderate and severe bleaching (the southern offshore reefs of the Marine Park).
There are reefs that severely bleached for the first time in 2020 and other reefs that bleached severely in 2016, 2017 and 2020.
Major tourism areas of the Reef mostly experienced no, negligible or moderate bleaching only - the exception is one area in the southern part of the Marine Park with severe bleaching.

Future outlook

From past bleaching events the Marine Park Authority anticipates corals on reefs with no or negligible bleaching will mostly recover and survive this event. Moderately bleached reefs are likely to show mixed responses depending on their history of disturbance. Corals on reefs with severe bleaching, however, are likely to have significantly higher, though variable, mortality rates.

While there are some in-water surveys continuing at present, due to COVID-19 travel and social distancing restrictions, on-water operational activity is constrained. The Long-Term Monitoring Program conducted by the Australian Institute of Marine Science remain an important source of information on the health of coral reefs in the Great Barrier Reef Marine Park. The Marine Park Authority will move to monthly Reef Health updates.

Weekly Reef health update — 26 March 2020

The Authority acknowledges the significant impact the COVID 19 virus is having on Reef related industries and communities. The Authority will continue to provide updates on Reef Health during this time.

Sea surface temperatures

As of 24 March 2020, sea surface temperatures (SSTs) across the Reef were mostly average and additional thermal stress is unlikely to accumulate. Although temperatures decreased, the effects of prolonged thermal stress are still being observed across the Marine Park and we continue to receive reports of coral bleaching. Reef-wide aerial surveys to determine the extent and severity of coral bleaching are currently underway.

The Authority has an observer on these surveys conducted by the Australian Research Council Centre of Excellence for Coral Reef Studies at James Cook University. Aerial surveys conducted last week showed most offshore reefs north of Cairns had no or low levels of bleaching. Moderate to severe bleaching was observed on inshore and mid-shelf reefs over this area.

Inshore and offshore reefs south of Cairns, particularly between Tully and Townsville, showed severe bleaching. There was an area offshore in this northern section where reefs were more moderately bleached, including high value tourism reefs. Inner and mid-shelf reefs surveyed between Townsville and Mackay were mostly severely bleached, but some were only moderately bleached in this central section, including high value tourism reefs.

Reefs in the Swains Pompey Reef complexes (the extreme southeast of the Marine Park) surveyed on 25 March 2020 show high variability in bleaching. There was about one-third with no or minor bleaching, one-third with moderate bleaching and the remaining third had severe bleaching. There was no consistent north-south or inshore-offshore pattern.

Next week's outlook

Aerial surveys will be completed later this week and the analysis of the aerial survey information will occur in the weeks to follow. After this analysis, we will provide further information how the whole Reef fared this summer.

Media statement

On 26 March 2020 the Marine Park Authority issued a media statement that confirms mass coral bleaching is occurring on the Great Barrier Reef, with very widespread bleaching detected.

Weekly Reef health update - 27 February 2020

Temperature

While recent cloud and rain provided cooling to some parts of the Great Barrier Reef, we are continuing to monitor the situation because the risks have not gone away. Local weather conditions over the next few weeks will play a key role in determining outcomes for the Reef this summer. Coral bleaching has been occurring on parts of the Reef where thermal stress has accumulated the most over summer.

In-water loggers and satellite data

A variety of information is used to understand conditions, including in-water temperature loggers monitored by the Australian Institute of Marine Science and satellite observations from the Bureau of Meteorology. Given the recent rain and cloud cover, we don’t have a complete picture of sea surface temperature trends and current conditions. We’ll get abetter understanding when satellites can see the Reef again.

In-water temperature loggers monitored by the Australian Institute of Marine Science currently indicate cooling over the last week at most locations across the Reef. Forecast tools from both the Bureau and the National Oceanic and Atmospheric Association (NOAA) indicate a high level of thermal stress is likely to build throughout the Marine Park for the rest of February and into March. Recent cloud cover may have restricted the ability of some satellites to accurately measure sea surface temperatures. As a result, modelled sea surface temperatures may appear warmer than it actually is, so data should be interpreted with caution.

Aerial and in-water surveys

We’ve continued to receive reports of coral bleaching from our aerial surveillance, in water surveys and from tourism operators and reef users. These show inshore and mid-shelf reefs assessed in the far north (north of Princess Charlotte Bay) mostly have widespread bleaching affecting most coral types, whereas offshore reefs assessed in this area show minimal to no bleaching.

Observations over large parts of the remainder of the Reef show no bleaching or isolated minor coral bleaching. For example, observations of reefs from Bowen to offshore Mackay and mid shelf reefs between Ingham and Cairns showed no or minimal coral bleaching during aerial surveillance last week and into the weekend. In some other locations, such as Cleveland and Halifax bays near Townsville, moderate to severe bleaching was observed on inshore fringing reefs. We’ve also received reports of more prevalent bleaching in some parts of the Capricorn Bunker Group.

Rainfall

As of 26 February 2020, most of the Great Barrier Reef coast and catchment received rainfall, with the highest totals falling just north of Mackay. Most river systems within the Marine Park catchment are currently below flood level. Salinity levels remain mostly normal, however some inshore areas between Townsville and Port Douglas and a small area near the Fitzroy River recorded lower salinity levels.

Weekly Reef health update – 20 February 2020

There’s important information about current conditions on the Great Barrier Reef in today’s Reef health update. Water temperatures across the Reef are increasing and reaching levels where some bleaching is being observed. We are investigating this — spot checks by divers, helicopter patrols, and citizen science observations are helping us build a bigger picture.

As was the case last summer, local and regional weather conditions have the potential to change this outlook and are a critical factor in outcomes this summer. However, with current thermal stress observations and forecasts, further bleaching may develop in the Great Barrier Reef this summer. We’re working closely with the Australian Institute of Marine Science, James Cook University, other science partners, Traditional Owners and the tourism industry to monitor conditions on the Reef throughout the summer.

Weekly Reef health update – 13 February 2020

Rainfall

As of 11 February 2020, most of the Great Barrier Reef coast and catchment received rainfall, with the highest totals falling in the northern Cape York Peninsula and in the Fitzroy River catchment. All rivers systems within the Marine Park catchment are currently below flood level. Salinity levels remain mostly normal, apart from a small area in Princess Charlotte Bay and coastal areas near the Tully and Herbert rivers where lower salinity levels were recorded.

Temperature

The Bureau of Meteorology’s ReefTemp tool indicates sea surface temperatures within the Marine Park have increased slightly since the previous update. As of 11 February 2020, most of the Marine Park was 0.5 to 1.5°C above average. Some inshore to offshore areas in the Far Northern, Central and Southern management areas were 2 to 3°C warmer. These areas also accumulated the most thermal stress since the start of summer. Monitoring by the United States National Oceanic and Atmospheric Administration (NOAA) shows most of the Marine Park is on “warning” for bleaching to occur.

Large parts of the Torres Strait and Far Northern management area of the Marine Park are on “Bleaching Alert Level 1.” (see table below) However, there is variability between the satellite-based models and more local in-water readings. In-water temperature loggers monitored by the Australian Institute of Marine Science currently indicate a high risk of bleaching at Myrmidon Reef and an extreme risk of bleaching at Davies Reef —both in the Central management area. A medium risk of bleaching is indicated in the Keppel Islands, with loggers in the northern half of the Marine Park indicating no or low risk of bleaching. Forecast tools from both the Bureau and NOAA agree some level of thermal stress is likely to be seen throughout the Marine Park in March.

Cyclones

Ex-tropical cyclone Uesi is currently located 495km north-northeast of Lord Howe Island. It is expected to continue moving slowly to the southwest and expected to cause destructive winds at Lord Howe Island later today. The Bureau of Meteorology is not expecting direct cyclone impacts on the Queensland east coast.

Weekly Reef health Update – 6 February 2020

Rainfall

As of 3 February 2020, most of the Great Barrier Reef coast and catchment received rainfall, with the highest totals between Cooktown in the far north and Cape Upstart in the south. All rivers systems within the Marine Park catchment are currently below flood level.

Temperature

The Bureau of Meteorology’s ReefTemp tool indicates sea surface temperatures within the Marine Park remained above average, but stable, since our previous update. As of 4 February 2020, most of the Marine Park was 0.5 to 1.5°C above average, except for some inshore to mid-shelf areas in the Far Northern and Southern management areas that were 2 to 2.5°C warmer. These areas have also accumulated the most thermal stress since the start of summer. The United States National Oceanic and Atmospheric Administration (NOAA) is indicating large parts of the Torres Strait — along with most of the northern half of the Far Northern management area — are on Bleaching Alert Level 1.

It is important to note the recent cloud cover has compromised the ability of some of the satellites to see what's happening on the ocean’s surface – so, the data should be interpreted with caution. For the remainder of the Marine Park, most of the mid-shelf and offshore reefs are on “Watch,” except for south of the Whitsundays where inshore and mid-shelf areas are on “Warning.”

In-water temperature loggers monitored by the Australian Institute of Marine Science are currently indicating a medium risk of bleaching at Heron Island and in the Keppel Islands, with loggers north of these indicating no or low risk of bleaching. Forecast tools from both the Bureau and NOAA agree some level of thermal stress is likely to be seen throughout the Marine Park in February.

Bleaching levels explained

The United States National Oceanic and Atmospheric Administration (NOAA) use several categories in their heat stress monitoring for coral reefs:

No stress: there is no stress level for corals, no hotspots and no bleaching
Bleaching Watch: there is at least one temperature hotspot in the area and marine managers are keeping an eye on this area
Bleaching Warning: bleaching is possible, there are several hotspots with elevated temperatures
Bleaching Alert Level One: significant bleaching is likely, there multiple hotspots with elevated temperatures
Bleaching Alert Level Two: the highest level, severe bleaching and significant mortality are likely.

Cyclones

There is currently a tropical low located over the northern Coral Sea. This system is not expected to develop significantly in the short-term, but may strengthen towards tropical cyclone intensity late this weekend or early next week.

Weekly Reef health update - 30 January 2020

A tropical low near the southern coast of the Gulf of Carpentaria caused significant rainfall and cloud cover across northern Australia over the past week, including across the Great Barrier Reef catchment. Most of the Great Barrier Reef coast and catchment received rainfall, with the highest totals between Princess Charlotte Bay in the far north and Shoalwater Bay in the south. However, this rainfall has not resulted in flooding of the catchment’s major river systems and it is expected to have negligible impacts on the Marine Park. The recent rain and cloud cover conditions over much of the Marine Park may have some cooling influence on sea surface temperatures over the coming weeks and this will continue to be monitored.

Temperature

The Bureau’s ReefTemp indicates sea surface temperatures in the Marine Park have increased since the previous update. As of 27 January, some inshore to mid-shelf areas in the Far Northern and Southern management areas were 2 to 2.5°C above the January average. These are the areas that have also accumulated the most thermal stress in the Marine Park since the start of summer. Local and regional weather conditions will have a key influence on sea surface temperatures over the next few weeks, and we will continue to monitor the situation closely.

The United States National Oceanic and Atmospheric Administration (NOAA) is indicating that parts of the Torres Strait — and the most northern part of the Far Northern management area — are on Bleaching Alert Level 1. The area from approximately Shelburne Bay south to Cairns is on Bleaching Warning. From Cairns to the southern boundary of the Marine Park, most inshore to mid-shelf areas are on Warning, while outer shelf areas are on Watch.

In-water temperature loggers monitored by the Australian Institute of Marine Science are currently indicating a high risk of bleaching at Thursday Island in the Torres Strait, and a medium risk of bleaching at Lizard Island in the northern Marine Park. All other logger locations south of Lizard Island currently indicate no or low risk of bleaching. Forecast tools from both the Bureau and NOAA agree that some level of thermal stress is likely to be seen throughout the Marine Park in February.

Bleaching levels explained

The United States National Oceanic and Atmospheric Administration (NOAA) use several categories in their heat stress monitoring for coral reefs.

No stress: there is no stress level for corals, no hotspots and no bleaching.
Bleaching Watch: there is at least one temperature hotspot in the area and marine managers are keeping an eye on this area.
Bleaching Warning: bleaching is possible, there are several hotspots with elevated temperatures.
Bleaching Alert Level One: significant bleaching is likely, there multiple hotspots with elevated temperatures.
Bleaching Alert Level Two: the highest level, severe bleaching and significant mortality are likely.

Reef health

Reports from our Eye on the Reef network indicated isolated instances of low level coral bleaching and coral disease in the Marine Park. Active crown-of-thorns starfish outbreaks continue in the central and southern Marine Park.

Weekly Reef health update - 24 January 2020

Temperature and rainfall

Sea surface temperatures in the Marine Park increased over the past week, mainly within the central and southern inshore areas in and throughout the far northern management area. The Bureau of Meteorology’s ReefTemp tool shows an increasing level of thermal stress in the far northern sector and in inshore and mid-shelf areas in southern area. Above-average air temperatures are expected to persist for much of the country into April, with a roughly equal chance of wetter or drier conditions than average during this period.

Forecast tools from the Bureau and the National Oceanic and Atmospheric Association currently predict a moderate risk of thermal stress throughout all sectors of the Marine Park over the coming months, but particularly within inshore areas. An area within the Torres Strait is on Bleaching Alert by the National Oceanic and Atmospheric Administration with elevated water temperatures concentrated to the north west of the region. Both the El Nino-Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) are now neutral and likely to remain so into April — when these main climate drivers are neutral, Australia’s climate can be influenced by more local or short-term drivers.

Reef health

The latest Australian Institute of Marine Science survey reports for the far northern area of the Great Barrier Reef show overall hard coral cover in the Cape Grenville and Princess Charlotte Bay sectors was moderate (10 to 30 per cent). Per cent coral cover in Cape Grenville was unchanged while there was a slight decrease in Princess Charlotte Bay. Coral bleaching was widespread, but restricted to low levels, with no crown-of-thorns starfish outbreaks reported.

Weekly Reef health update - 17 January 2020

Sea surface temperatures

Sea surface temperature anomalies in parts of the Marine Park increased slightly over the past week, mainly in the Far Northern area. The Bureau of Meteorology’s ReefTemp tool also suggests there is a low level of thermal stress accumulation in the Far Northern and inshore Southern areas. Above average temperatures are likely to continue for much of Australia into April. Most of eastern Queensland is likely to be drier than average through to the end of this month. Forecast tools from the Bureau and National Oceanic and Atmospheric Administration currently predict a moderate risk of thermal stress throughout the Marine Park over the coming months.

Eye on the Reef

Reports from the Eye on the Reef network have indicated only isolated instances of low level coral bleaching and coral disease in the Marine Park. Active crown-of-thorns starfish outbreaks continue in the central and southern Marine Park.

Weekly Reef health update - 10 January 2020

Temperature and rainfall

Over the past fortnight, sea surface temperatures in the Marine Park have been mostly average, apart from some areas of the Far North which were up to 2°C above average. The Bureau of Meteorology’s ReefTemp tool indicates there is currently a low level of thermal stress accumulation around inshore areas in the Far Northern and Southern sectors of the Marine Park.
Above-average temperatures are likely to continue for much of Australia including Queensland into April. Most of eastern Australia is likely to be drier than average through to the end of this month. Forecast tools from the Bureau and National Oceanic and Atmospheric Administration currently predict a moderate risk of thermal stress in the Marine Park over the coming months.

Tropical cyclones

The first tropical cyclone of the season for Australia, tropical cyclone Blake, made landfall on Wednesday morning 8 January 2020 in Western Australia. A second tropical system currently over the Arafura Sea (west of the Pacific Ocean) is forecast to develop to tropical cyclone intensity in the coming days, potentially making landfall on the north coast of the Northern Territory in Australia. There are currently no significant tropical low systems in the eastern region and none expected to develop.

Summary of 2018-2019 summer

Over the 2018–19 summer we published weekly updates on the health of the Great Barrier Reef as this is a high-risk time for the Reef. We’ve combined information from those weekly summaries to produce this wrap-up of summer conditions and impacts.

Temperature and sea surface temperature

The El Niño-Southern Oscillation — the weather’s movement between El Niño and La Niña conditions — remained neutral but near El Niño levels throughout summer and autumn. Summer 2018–2019 was the warmest summer on record for Australia. In Queensland, it was the fourth warmest summer on record in terms of mean temperature. It included the third warmest December, the warmest January on record, and a warmer than average February. The autumn months of March and April were also warmer than average.

Sea surface temperatures were above average throughout the Marine Park for most of summer, peaking through January and February. However, the cooler regional weather conditions (associated with the monsoon trough and tropical cyclones) reduced sea surface temperatures back to average or slightly below average for several weeks, markedly reducing the accumulation of thermal stress and the associated threat of mass coral bleaching.

Coral bleaching and disease

There was no significant large-scale coral bleaching event in the Marine Park this summer. Minor bleaching was reported from all management zones in the Marine Park, however these instances were generally at the scale of individual colonies. Low level coral bleaching is normal over the summer months as corals become stressed by warmer ocean temperatures. In addition, low level coral disease was reported from all management zones in the Marine Park at local to regional scales. Coral disease is a natural part of the system and is often reported at low levels throughout the Marine Park during the summer months.

Rainfall and floods

Rainfall this wet season (October 2018 to April 2019) was strongly influenced by monsoon and cyclone activity. While rainfall was below average for most of Australia, it was very much above average for large parts of northern Queensland during the summer months and into March and April 2019. In late January to early February 2019, a monsoon trough and associated low pressure system brought torrential rain to the Townsville region and caused major flooding. Extensive flood plumes developed along the coast between Bowen and Cooktown, including a major plume from the Burdekin River which extended up to 100 kilometres offshore, reaching mid- to outer-shelf reefs.

Initial results and modelling indicated flood plumes from the combined effect of the monsoon rains, and the heavy rains associated with tropical cyclone Trevor, significantly reduced salinity levels in inshore regions of the Marine Park between Lockhart River and Bowen. In some areas, lowered salinity levels were recorded as far out as the mid-shelf reefs. Salinity levels subsequently returned to normal in many areas, however as of the end April, salinity levels were still lower than average (for the Great Barrier Reef) in the shallow inshore areas between the tip of Cape York and Townsville.

As of the end of April 2019, surveys of seagrass meadows and inshore coral reefs throughout the flood-plume affected regions had indicated little noticeable change. Isolated cases of freshwater bleaching on inshore coral reefs in the Townsville regions were reported, however overall coral mortality was low.

Animal strandings and key habitats

As at the end of May 2019, there have been no reported increases in strandings of marine animals reliant on seagrass meadows, such as green turtles or dugongs. The longer-term impacts on inshore coral reefs and seagrass meadows depends on the duration and degree of exposure of these habitats to flood plumes and reduced salinity. Monitoring of these habitats in key areas will be ongoing in order to identify any lag effects.

Cyclones

It was an average cyclone season (November to April), with four tropical cyclones affecting the Queensland region – Owen (December), Penny (January), Oma (February) and Trevor (March). In addition, a fifth cyclone, Ann, occurred out of season in mid-May. Tropical cyclone Trevor and ex-tropical cyclone Penny caused extensive rainfall and flooding of Far Northern river systems, leading to large flood plumes. Some rivers reached their highest flood height on record, and the subsequent flood plumes reached mid-shelf reefs around the Lockhart River region.

Full assessments of coral damage as a result of the five tropical cyclones/tropical lows which affected the Marine Park are pending. Preliminary cyclone wave damage modelling by the Australian Institute of Marine Science (AIMS) indicates there is likely to be some damage to coral reefs, particularly from tropical cyclone Trevor and ex-tropical cyclone Penny in the far northern part of the Marine Park.

AIMS Long-Term Monitoring Program surveys of far northern reefs in January confirmed signs of storm damage attributable to Penny. While tropical cyclone Oma did not enter the Marine Park, the winds and swell it generated affected the southern Great Barrier Reef. Wave damage and salt water incursion has been reported from islands and cays in the southern Marine Park.

Crown-of-thorns starfish

Active outbreaks of the coral-eating crown-of-thorns starfish are ongoing on reefs in the Northern, Central and Southern management areas. The Authority’s recently expanded Crown-of-thorns starfish control program continued targeted, proactive surveillance and culling on reefs of high tourism and ecological value in the Marine Park to reduce (or maintain) the starfish at densities that allow for coral growth. This includes surveillance and management of crown-of-thorns starfish on high value reefs in the Far Northern management area for the first time in the program’s history.

Weekly Reef health update - 20 December 2019

Temperature and rainfall

Rainfall across northern Australia has been well below average, with most of the tropics receiving less than 20 per cent of normal December rainfall. In the past few days, a low intensity heat wave has been affecting most of Queensland, apart from isolated areas along the coast. The southwest and western parts of the State reported severe heatwaves.

Over the past fortnight, sea surface temperatures throughout the majority of the Marine Park have been average to slightly above average, apart from isolated inshore areas of the southern Marine Park which were up to 2°C above average. The Bureau of Meteorology (BoM) ReefTemp tool indicates there is currently a low level of thermal stress accumulation throughout the Marine Park, and it is probable that this heating over the past few weeks has negated any buffer that existed in the Marine Park following a cooler winter.

The patterns of above-average temperatures and below-average rainfall are predicted to continue for northern Australia, at least until the monsoon becomes established in mid- to late-January – this is likely to mean calm, clear and dry conditions for the next few weeks which could likely contribute to thermal stress accumulation. While there is no immediate threat of significant thermal bleaching, the Marine Park Authority remains on watch, with both BoM and United States’ National Oceanic and Atmospheric Administration showing a bleaching watch situation for the far northern Marine Park and inshore regions in the Central and Southern management areas.

Eye on the Reef

Reports on another round of coral spawning have been received through the Eye on the Reef sightings network.

Crown-of-thorns starfish (COTS) management program

The Reef Joint Field Management Program COTS response team have discovered a new outbreak of coral eating starfish on a priority reef in the offshore central Marine Park. A control team will be tasked with culling COTS on this reef in the New Year.

Weekly Reef health update - 13 December 2019

Temperature and rainfall

Conditions are currently hot and dry across the Great Barrier Reef catchment and are likely to remain so well into January. Over the past few days, a low intensity heat wave has been affecting most of Cape York Peninsula. The Australian Bureau of Meteorology’s ReefTemp product indicates that sea surface temperatures in the inshore areas of the far northern Marine Park are slightly above average.

The United States National Oceanic and Atmospheric Administration (NOAA) uses satellite sea surface temperature monitoring to determine where coral bleaching stress reaches various levels.The National Oceanic and Atmospheric Administration has placed this area on bleaching watch, along with parts of the Torres Strait and the Gulf of Carpentaria. Sea surface temperatures are also slightly warmer than average in the inshore areas of the southern Marine Park however there is currently no bleaching watch for this area. In the remainder of the Marine Park, sea surface temperatures are average to below average. A low level of thermal stress is beginning to accumulate throughout the region, however there is currently no threat of significant thermal bleaching for the majority of the Marine Park.

Crown-of-thorns starfish (COTS) management program

The Reef Joint Field Management Program crown-of-thorns starfish (COTS) response team recently returned from the Whitsundays region where they surveyed eight offshore reefs of high tourism and ecological value. While there was evidence of crown-of-thorns on some of these reefs, no outbreaks were found. In addition, while the impacts of Cyclone Debbie (2017) are still visible across these reefs, signs of recovery were observed in some areas. Monitoring will continue, and our proactive crown-of-thorns starfish control measures will be undertaken if necessary, to prevent potential outbreaks developing on these high value reefs.

Merry Christmas

We will take a short break from reporting on Reef health during the festive season, however conditions will still be closely monitored over this time. If you are out on the Reef over the holidays, we remind you to stay safe and also make sure that you are familiar with the Marine Park rules, including zoning restrictions. Free zoning maps are available from local bait and tackle shops or visitor information centres, or by downloading the free Eye on the Reef zoning app.

Any suspected illegal activity can be reported to our free 24-hour hotline 1800 380 048 or online – information on how to do this is available on our website. Anyone can also report interesting sightings or reef health incidents through the Eye on the Reef app, so we can all play a part in keeping an eye on the reef this holiday season.

Weekly Reef health update - 6 December 2019

Temperatures and rainfall

We are now officially at the start of summer. Spring 2019 was officially the fourth driest and the fifth warmest Spring on record for Queensland. Conditions are hot and dry across the Great Barrier Reef catchment. This is directly due to the low to severe intense heatwaves over the last few days. Heatwaves are expected to continue to affect the region over the coming days.
Sea surface temperatures throughout the Marine Park are average to below average, with no current threat of significant thermal bleaching. We use a specific tool designed to determine the accumulation of thermal stress in the Marine Park including mapping of Degree Heating Days. Models indicate there appears to be some level of thermal stress beginning to accumulate in some inshore regions from Townsville south and in the inshore to mid-shelf regions from Mackay south.

Forecasting modelling

Forecast tools from the Australian Bureau of Meteorology and United States National Oceanic and Atmospheric Administration indicate some level of thermal stress is likely to be seen throughout the Marine Park by the end of January. Areas to watch for coral bleaching in December and January include the central and southern management regions ( between the Bowen and Gladstone regions).

Reef health

Large suspended algae blooms have been reported via the Eye on the Reef sightings network. This is normal for this time of year and thought to be associated with the annual coral spawning event. If you witness further algal blooms through the Marine Park, submit the sighting via the Eye on the Reef app or sightings network.

Weekly Reef health update - 29 November 2019

Dr James Kerry, acting Chief Scientist for the Great Barrier Reef Marine Park Authority, presents a pre-summer weekly update on the Reef. Summer Reef update video may be watched by clicking here -

Pre-summer workshop

Scientists and Reef health managers are not, at this point, expecting to see a marine heatwave or severe mass coral bleaching on the Great Barrier Reef this summer. However, local weather conditions will have a key influence on sea surface temperatures during the summer. This was a key conclusion from the annual pre-summer workshop convened by the Authority late November to predict potential impacts on the Great Barrier Reef during the highly sensitive summer period. The workshop brought together scientists, marine and tourism managers, reef managers and experts to look at how the Reef will fare over summer. A recent media release on the outcome of the workshop is available.

Temperatures

Sea surface temperatures throughout the Marine Park are currently average to slightly above average, with no current threat of significant thermal bleaching. Forecast tools from our partners at the Australian Bureau of Meteorology indicate that December may bring some thermal stress to the Whitsundays. There may be some thermal stress between Mackay and Rockhampton areas around the inshore to mid-shelf areas.

Crown-of-thorns starfish (COTS) management

The Authority has received Eye on the Reef Sightings reports of crown-of-thorns starfish on several reefs offshore from the Whitsundays. This area is of high importance for the resilience of both coral reefs and reef-based industries.

In response, our Field Management Program will deploy a vessel at the beginning of December to assess reef health and the impacts of crown-of-thorns on these high value reefs in this region. The data collected will be used to strategically plan any future crown-of-thorns control activities on these reefs. Outbreaks of crown-of-thorns starfish are ongoing in the central and southern Marine Park, with the most severe outbreaks occurring in the outer parts of the southern region.

Reef health

There have been multiple reports of coral spawning through the Eye on the Reef Sightings Network throughout the Marine Park. Some localised minor levels of bleaching have been reported, coral disease and coral damage in each management area of the Marine Park. A giant, filter-feeding whale shark was also reported in the Whitsundays. The timing of this sighting and past sightings indicates that whale shark presence in the Whitsundays aligns with the annual coral spawning, a favoured food source for this majestic animal.

Pre-summer Workshop

Coral-eating starfish are being managed successfully on a number of reefs thanks to an innovative, world-leading control program, but with one of the top three warmest years on record for Queensland expected, some coral bleaching due to local weather conditions is a possibility for our Great Barrier Reef this summer.

That was a finding from this year’s annual pre-summer workshop convened by the Great Barrier Reef Marine Park Authority to predict potential impacts on the Great Barrier Reef during the highly sensitive summer period. The workshop brings scientists, marine and tourism managers, reef managers and experts together to look at how the Reef will fare over summer – with partners including the Bureau of Meteorology, Australian Institute of Marine Science, James Cook University and the US-based National Oceanic and Atmospheric Administration. Great Barrier Reef Marine Park Authority Chief Scientist Dr David Wachenfeld said "a marine heatwave or severe mass coral bleaching was not forecast at this point as Reef waters were expected to be only a little warmer than average this summer."

Weekly Reef health update - 15 November 2019

Temperature and rainfall outlook

Sea surface temperatures throughout the Marine Park are currently average to slightly below average, with no threat of significant thermal bleaching. The Australian Bureau of Meteorology daytime temperatures for summer are likely to be warmer than average across Australia, including the Reef catchment, for the remainder of 2019 and into early 2020. The onset of the Australian monsoon season in 2019-2020 is likely to be delayed.

Reef Health Impacts

Reports of coral spawning on offshore reefs within the northern sections of the Marine Park have been received this past week via the Eye on the Reef sightings network.

Summer planning

Planning for the higher risk summer season has commenced, with our annual pre-summer workshop to be held next week in Townsville. The workshop will bring together scientists, managers and key stakeholders to discuss the events of last summer on the Great Barrier Reef and the outlook for the coming summer.

Weekly Reef health update - 8 November 2019

Temperature and rainfall outlook

Sea surface temperatures throughout the Marine Park are currently around average, with no threat of significant thermal bleaching. The Australian Bureau of Meteorology forecast warmer and drier than average conditions for the Reef catchment for the remainder of 2019. In December, sea surface temperatures are likely to be average for most of the Marine Park, except the inner and mid-shelf areas from Mackay southwards (above average) and parts of the Far Northern management area towards the tip of Cape York (slightly cooler).

Reef health impacts

Reports from the Australian Institute of Marine Science and the Eye on the Reef network indicate there are local cases of low level coral bleaching, disease and damage in all regions of the Marine Park, excluding the far northern region which remains to be surveyed. These impacts are within the normal range expected for this time of year. There are ongoing outbreaks of crown-of-thorns starfish in the central and southern Marine Park. Numbers of the coral eating crown-of-thorns starfish have increased in the Pompey sector and decreased in the Swains areas of the southern Marine Park, according to the Australian Institute of Marine Science.

Five crown-of-thorns starfish control vessels are still working in conjunction with the Australian Institute of Marine Science to conduct plankton sampling throughout the starfish spawning season (November to February), as part of a research project developing the use of eDNA to monitor levels of starfish larvae.

Monthly Reef health update - October 2019

Temperature and rainfall outlook

Sea surface temperatures throughout the Marine Park are currently around average, with no threat of significant thermal bleaching. The Australian Bureau of Meteorology forecast warmer than average conditions and less rainfall than usual for the Reef catchment for the remainder of 2019. Near average sea surface temperatures are predicated for the next two months, except in the southern Marine Park where slightly above average temperatures are expected.

Tropical cyclones

The Australian tropical cyclone season runs from November to April. On average, there’s about four cyclones in or near the Reef each season and one may make landfall. The Australian Bureau of Meteorology tropical cyclone season outlook for 2019-2020 indicates there’re likely to be less cyclones in this region this season. Importantly, this forecast does not predict cyclone severity or damage from wind, large waves, storm surges, widespread rainfall and dangerous flooding in the Great Barrier Reef region.

Summer management planning

Preparations are currently underway for our pre-summer workshop, which will be held in November and involve leading reef managers, scientists and experts looking at what might happen over summer. At this workshop, the previous summer is reviewed along with current conditions, early warning tools and climate outlooks for the upcoming summer to assess the short-term environmental risk for the Reef. The workshop findings guide preparations for the upcoming summer, including considering risks to Reef-reliant communities and industries.

Eye on the Reef — sightings

Coral spawning was observed a several inshore reef locations throughout the Marine Park this month. The time of year that corals spawn depends on their location — inshore reefs usually start spawning one to six nights after the full moon in October and outer reefs usually spawn during November or December when ocean temperatures begin to warm towards the start of the Australian summer. In addition to replenishing the coral cover on coral reefs, the mass coral spawning events also provide a food source for other marine creatures, including plankton and some fish species.

Crown-of-thorns starfish control program

All five crown-of-thorns starfish control vessels are working in conjunction with the Australian Institute of Marine Science to conduct plankton sampling throughout the starfish spawning season (November to February), as part of a research project developing the use of eDNA to monitor levels of starfish larvae.

Monthly Reef health update - September 2019

Two-week Sea Surface Temperature Anomaly

In the two weeks up to 23 September 2019, sea surface temperatures were slightly below average throughout the Marine Park, except for the southern area where sea surface temperatures were average to slightly above average.

Temperature and rainfall outlook

The Australian Bureau of Meteorology forecast warmer than average conditions and less rainfall than usual for the Reef catchment for the remainder of 2019. Average sea surface temperatures are predicated for this time, except for in the far northern Marine Park where sea surface temperatures are likely to be slightly cooler than average in October.

Crown-of-thorns starfish control program

We run a crown-of-thorns starfish control program in the Marine Park, involving several control vessels. One of these control vessels is currently working on three high value tourism reefs in the Capricorn-Bunker Group (southern Marine Park). On one of these reefs, the team achieved sustainable ecological thresholds of the coral-eating starfish at 18 of the 22 starfish cull sites identified by surveillance.

Surveillance on the other two reefs didn’t find starfish at outbreak levels, however pro-active culling was used to prevent the start of an outbreak. In the central region of the Marine Park, control vessels are focusing on five reefs showing starfish outbreaks on a scale from potential to severe level thresholds. In the northern Marine Park, there’s plans to check the Lizard Island area ahead of schedule and in collaboration with researchers. This follows observations presented at the recent National Environmental Science Program workshop.

Eye on the Reef — Sightings

A number of humpback whale sightings were reported through our Sightings Network in September, which is towards the end of their annual migration period, with most heading south back to Antarctica. Four fruit bats were found at Heron Island in September — it’s a very rare sight to see these bats that far off the coastline, suggesting the animals may be seeking food and refuge.

An egg mass from either a diamond or bigfin squid were recorded in the Marine Park near Mackay Cay out from Cape Tribulation. These long sausage-like, transparent, floating egg masses are found throughout the world’s tropical and sub-tropical waters, but not commonly captured on video.

Monthly Reef health update - August 2019

In August 2019, we released our 2019 Outlook Report — it provides a comprehensive summary of Reef health and management, including the future outlook for the Great Barrier Reef (the next five to 25 years). The Australian and Queensland Governments also released the Reef Water Quality Report Card 2017 and 2018. For the first time, results are reported at a finer catchment and sub-catchment scale.

Climate outlook

Winter 2019 was warmer than average, and one of the driest winters on record for much of Australia. Predictions indicate Queensland is likely to be warmer and drier than average for the remainder of 2019. It is also highly likely the Great Barrier Reef catchment, Cape York Peninsula, and coastal parts of Queensland will experience late onset rainfall this season.

Crown-of-thorns Starfish Control Program

One of our crown-of-thorns control vessels completed three voyages to the Capricorn Bunkers group to focus on high value reefs. The majority of intensive control effort was focused around Lady Musgrave Island, with more than 300 dive hours spent culling over 2000 crown-of-thorns starfish. While initial surveillance at Lady Elliott Island indicated crown-of-thorns starfish were below outbreak levels, control teams proactively searched and culled at all at-risk sites around the reef in order to prevent the development of an outbreak. Both of these reefs were assessed as having healthy coral cover.

Raine Island sand re-profiling

Remote Raine Island — home to the world’s largest remaining green turtle nesting population and an important seabird rookery — will undergo the third major sand re-profiling exercise beginning this month as part of the five-year Raine Island Recovery Project.

Eye on the Reef - Sightings

There’s been some anecdotal reports from a local tourism vessel of ‘cold snap’ bleaching occurring at Davies Reef. A rare and amazing sighting of a whale shark was recently spotted in the Coral Sea and reported through the Eye on the Reef app. All types of coral reef health reporting are important for identifying current reef conditions — please bring it to our attention through the Eye on the Reef App or sightings network.

Monthly Reef health update - July 2019

Climate Outlook

August to October is expected to be drier than average across the Great Barrier Reef catchment. Temperatures around the coastal regions south of Cairns are expected to be warmer than average conditions.

Salinity levels

Salinity levels of inshore regions between the tip of Cape York and Townsville (including Princess Charlotte Bay) have returned to near normal levels (34-35parts per thousands), after a prolonged period of below average salinity conditions as a result of the northern wet season.

Crown-of-thorns Starfish Control Program

We received critical field intelligence about outbreaks of the coral-eating starfish at several reefs in the Capricorn Bunkers. We’ve deployed a control vessel to the Capricorn Bunker group to focus on six high value reefs.

Sea Surface Temperatures

As the cooler months set in, July saw colder sea surface temperature from Lockhart River, north of Cooktown, to Rockhampton. It was one degree below average temperature in the Townsville region. Sea surface temperatures during August are expected to remain cooler than average in the northern and far northern areas of the Marine Park, average in the central regions, and slightly above average for the southern Great Barrier Reef.

Eye on the Reef / Sightings

Tourism industry data from their regular dive sites continue to show typical winter conditions. These colder water conditions slowed the growth of certain organisms, resulting in reduced macroalgae and coral colony diseases. There’s increasing submissions through our sightings network from tourism operators about crown-of-thorns starfish around the Capricorn Bunkers near Rockhampton, providing early warning data.

And there’s good news too — the stars continue to shine, with several reports of humpback whales and minke whales. There was an interesting sighting t of two white whales travelling north inside Tongue and Batt Reef, offshore from Port Douglas. Seeing a whale in the Marine Park is a special and memorable experience and, to ensure it happens safely, there are rules in place to protect onlookers and the whales:

vessels must stay at least 100 metres from whales in the Marine Park
vessels must stay at least 300 metres in the Whitsunday Whale Protection Area.

Marine monitoring activities

A good news story from the Southern Great Barrier Reef is the recovery of coral on One Tree Island in the Capricorn-Bunkers. After severe impact from cyclone Hamish in 2009, researchers from Southern Cross University found remarkable recovery of both reef calcification and coral cover to pre-cyclone conditions. The Australian Institute of Marine Science’s annual Great Barrier Reef Condition Update report shows mixed results for coral cover across the northern, central, and southern regions of the Great Barrier Reef. Collective disturbances of crown-of-thorns, cyclones and coral bleaching during the last five years caused declines in hard coral cover to moderate levels across much of the Reef.

Monthly Reef health update - June 2019

El Niño and Indian Ocean Dipole

The ENSO Outlook remained near El Niño thresholds. However, climate models suggest a shift away from El Niño in the coming months and moving towards an Indian Ocean Dipole (IOD), bringing warmer and drier than average conditions to much of Australia.

Climate Outlook

July to September is expected to be warmer and drier than average for most of Australia, however northern Queensland is expected to have near average winter conditions.

Salinity levels

Salinity levels of inshore regions between the tip of Cape York and Townsville (including Princess Charlotte Bay) have returned to near normal levels at 34-35psu, following a prolonged period of below average salinity conditions following the northern wet season.

Crown-of-thorns Starfish Control Program

Over the last month, the crown-of-thorns starfish (COTS) control vessels completed management activities at 21 high value coral reefs, culling over 17,500 COTS to protect coral and enhance the resilience of the Reef.

Eye on the Reef sightings network

Over the last month we have seen some interesting sightings submitted through our Eye on the Reef App showcasing the reef’s World Heritage biodiversity values. The real stars of the show this winter are the whales with the seasonal arrival of the famous Minke Whales. The first report this year came from the Ribbon Reefs. Since then several others have reported experiencing this incredible interaction, at Opal Reef and Flynn Reef in the northern part of the Great Barrier Reef. A particularly exciting sighting was a Brydes Whale feeding between Lady Elliot Island and Lady Musgrave Island in the southern tip of the Great Barrier Reef – a fantastic observation that showcases the whale’s behaviour in the World Heritage Area. Seeing a whale in the Marine Park is a special and memorable experience and, to ensure it happens safely, there are rules in place to protect onlookers and the whales:

vessels must stay at least 100 metres from whales in the Marine Park, and
at least 300 metres in the Whitsunday Whale Protection Area

Marine monitoring program activities

The Authority, Australian Institute of Marine Science and James Cook University continue to conduct monitoring activities throughout the Marine Park. This includes coral monitoring, water quality surveys and seagrass sampling.

Sea surface temperatures

With the onset of winter, sea surface temperatures continue to decrease throughout the Marine Park. Sea surface temperatures winter forecasts are for slightly below average from Cairns to north of the Marine Park. Average winter conditions remain for the Whitsundays to Capricorn Coast regions and above average winter sea surface temperature’s predicted for the southern regional areas of the Marine Park.

Monthly Reef health update - May 2019

Unseasonal cyclone activity

An out-of-season tropical cyclone, tropical cyclone Ann, approached the far northern area of the Marine Park as a category two system on 12 May, but rapidly weakened to a tropical low before entering the Marine Park and crossing the far north Queensland coast near Lockhart River on 15 May. The system produced moderate rain falls in far north-eastern Queensland.

Dry season conditions returning

The dry season is returning after out-of-season rainfall across northern Australia. However warmer than usual conditions are likely to continue across the north, until temperatures across the south of the continent drop significantly.

El Niño and Indian Ocean Dipole

The ENSO Outlook was downgraded in May, with models now predicting a 50 per cent chance of an El Niño developing (down from a 70 per cent chance last month) by mid-2019. While sea surface temperatures are predicted to remain close to El Niño thresholds until mid-winter, water beneath the surface has cooled. A neutral ENSO state is most likely by October 2019.

Reef monitoring in the Whitsundays

The Australian Institute of Marine Science completed long-term monitoring surveys of the Whitsundays area of the Great Barrier Reef in May 2019. These are the first surveys of the area since cyclone Debbie in 2017. Surveys indicate coral cover on two of the reefs surveyed declined slightly since the last survey, which is most likely due to tropical cyclone Debbie. Overall, average coral cover in this area remains at moderate levels (10 to 30 per cent).

Whale season underway

May marks the start of the humpback whale season on the Great Barrier Reef. From May to September each year, humpback whales come from Antarctic waters to the Great Barrier Reef World Heritage Area to calve and build up strength over the winter before they return to the Antarctic in summer. Sightings of whales or other wildlife can be captured and shared using our Eye on the Reef app.

There’s been multiple significant impacts on the Great Barrier Reef over the last five years, with some of the most significant of those impacts occurring since 2016.

This includes severe cyclones and subsequent flood plumes, outbreaks of coral disease and crown-of-thorns starfish, and an unprecedented two years of back-to-back mass coral bleaching events. Over this period, most of these impacts were concentrated in the northern two-thirds of the Marine Park. For the first time in the history of the Australian Institute of Marine Science’s (AIMS) Long-term monitoring program, trends in average hard coral cover on reefs in all three regions showed a decline.

By mid-2018, coral cover in the Region’s north was less than half of what it was in 2013. This was unprecedented and due to mortality caused by two severe cyclones, severe coral bleaching in 2016 and 2017, and ongoing crown‐of‐thorns starfish outbreaks. The Reef’s scale and natural resilience means it has the capacity to recover from impacts to an extent, given benign environmental conditions and adequate time free from disturbance. Under a changing climate, recovery capacity is already limited and will be further impaired should the frequency of bleaching events increase as predicted.

Monitoring reef health

We use the best available science contributed by a wide range of research institutions, government agencies, and universities to manage the Reef and ensure it remains healthy for future generations. There’s a range of programs in place to look at Reef health, including our Reef Integrated Monitoring and Reporting Program, the Reef 2050 Marine Monitoring Program, and the Long-term Monitoring Program by the Australian Institute of Marine Science.

Any long-term impacts on coral reefs will be detected by surveys from these programs. Because it’s important to have accurate, real-time information on Reef conditions, we work together with our Queensland Government partners and key stakeholders to gather observations of reef health and impacts through the Eye on the Reef program. Any visitors to the Reef can also report interesting sightings, or observations of coral bleaching, disease, predation or damage through the Eye on the Reef app.

Published every five years, our Outlook Report also provides a holistic view of Reef health and management. The next report will be published in mid-2019.

Wheeler Reef - Commonwealth of Australia (Reef Authority)

Corals - Great Barrier Reef - Copyright-Commonwealth of Australia (Reef Authority)

Pin Cushion Sea Star - Great Barrier Reef - Commonwealth of Australia (Reef Authority)

Coral bommie - Great Barrier Reef - Commonwealth of Australia (Reef Authority)

Snorkeler swimming over coral reef - Great Barrier Reef – Australia - © Tourism and Events Queensland

Created Tue, 2022-08-23 15:36

Updated 2 Apr 2024

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