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

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.
The Reef snapshot: summer 2022-23 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.
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 altitude 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.
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.
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.
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.
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
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 needed.
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
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 have been made 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.
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
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. Preparations have been made 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.
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.
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 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.
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 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.
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.
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.
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.
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.
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
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.
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.
- 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 are multiple hotspots with elevated temperatures.
- Bleaching alert level Two: the highest level, severe bleaching and significant mortality are likely.




