As the lead managers of the Great Barrier Reef, the Reef Authority keeps an eye on the Reef year-round — with efforts stepped up over summer, a typically high-risk period from extreme weather.
The Reef Authority releases updates on the health of Reef which includes; sea surface temperatures, rainfall and floods, cyclones, crown-of-thorns starfish outbreaks, and coral disease.
These updates are based on forecasts, water temperature heat mapping, in-water surveys, citizen science and aerial surveys.
Reef Health update | 06 March 2025
We will continue to monitor the cyclone off the Queensland coast and the potential impacts to the Reef. However, at this stage the forecast is predicting that Cyclone Alfred will continue to move south away from the Great Barrier Reef Marine Park.
Cyclone Alfred caused severe wind and wave conditions in the eastern part of the Southern region over the weekend.
Sea surface temperatures remain above average in the Marine Park, however the temperatures are predicted to cool in the coming weeks.
We are continuing to investigate the impacts from the heavy rainfall and flooding event in northern Queensland last month. Satellite imagery has shown extensive flood plumes extending more than 700km along the coastline, spread across inshore, midshelf and outer reefs, seagrass meadows and other marine ecosystems. It’s expected that freshwater has caused damage to some exposed ecosystems.
Targeted aerial surveys are scheduled next week in the Far Northern and Northern regions to assess any Reef health impacts that can be seen from the air.
Temperatures
Sea surface temperatures are slightly above average throughout the Marine Park. In the Northern region temperatures are 0.9-degrees above average, while they have decreased in the Central region to 0.3-degrees above average. Sea surface temperatures remain steady in the Far Northern (0.8-degrees) and Southern (0.4-degrees) regions above average.
The forecasts predict that sea surface temperatures will return to average or near-average temperature later this month.
Rainfall
Rainfall is likely to continue to be above average across much of Northern Australia from March to May.
Reef health
Over the past fortnight, 126 Reef Health Impact Surveys (RHIS) were conducted across the Marine Park. From the 14 sites surveyed, 11 had some level of coral bleaching recorded. In the Central and Southern regions, most reefs showed low levels of coral bleaching — 1 to 10% bleaching prevalence. While in the Northern region some reefs showed medium levels of coral bleaching — 11-30% prevalence.
Targeted aerials surveys will be conducted next week in the Far Northern (North of Cooktown to Cape York) and Northern regions (Cairns to Cooktown) to assess any Reef health impacts that are visible from the air resulting from temperature stress and flooding.
As of 14 February, Crown-of-thorns starfish (COTS) outbreaks are most severe in the Southern Region (Swain Reefs) and between Port Douglas and Lizard Island. Isolated and less severe outbreaks are persisting offshore Townsville and the Whitsundays. The Crown-of-thorns Starfish Control Program is continuing to suppress outbreaks and protect coral across hundreds of reefs.
Reef management
As the lead managers of the Reef, we are working closely with our partners to monitor conditions across the Marine Park during these high-risk summer months.
We also use a range of management actions to support and build Reef resilience, including enforcing compliance with our zoning plan and ensuring people enjoy the Reef in a responsible way.
You too can help by reporting any incidents through the Eye on the Reef app, which is available for download on Google Play or Apple Store.
Reef Health update | 19 February 2025
The impacts of the recent heavy rainfall and flooding across north Queensland are continuing to be assessed, including any changes to the Great Barrier Reef’s water quality.
Major to moderate flooding levels have been observed across nearly all river basins covering over 500 kilometres of coast between Cairns and Mackay. Significant flood plumes have been detected entering the Reef lagoon from all affected river systems some of which extend from the inshore to mid-shelf reefs.
The recent low-pressure systems across the Great Barrier Reef in the past weeks did have a cooling effect on sea surface temperatures.
Despite the cooling effect, sea surface temperatures in all regions of the Marine Park remain above historical averages. In the Northern and Central areas of the Marine Park this cooling has been short lived.
Temperatures
Sea surface temperatures have cooled across the Marine Park but continue to exceed historical averages.
The forecast for March indicates sea surface temperatures will remain 0.5–1-degrees Celsius above average across the Reef.
Rainfall
Rainfall is likely to continue to be above average across much of Northern Australia from March to May.
Reef health
Over the past fortnight, 175 Reef Health Impact Surveys (RHIS) were conducted across 19 reefs in the Marine Park. These surveys provide a detailed snapshot of reef health, including a breakdown of habitat and impact assessment.
Reefs surveyed in the Northern, Central and Southern regions showed low levels of coral bleaching—1 to 10% bleaching prevalence. No data was available for reefs in the Far Northern Region.
The Marine Monitoring Program is out sampling sites in the Mackay−Whitsundays, Burdekin, and Wet Tropics areas following the heavy rainfall over the past few weeks. Aerial and satellite imagery is being used to view and assess the flood plume extent, which is expected to move north and east.
Nutrient and sediment-rich, low salinity waters discharging from rivers after heavy rainfall can be detrimental to Reef health, increasing susceptibility to coral disease and bleaching. Prolonged exposure to these waters over the coming weeks could significantly impact the Reef in some locations through reduced light and promotion of algal blooms over large areas.
These stresses can contribute to localised seagrass and coral mortality.
As of last week, crown-of-thorns starfish (COTS) outbreaks were most severe in the Southern Region (Swain Reefs) and between Port Douglas and Lizard Island. Isolated and
less severe outbreaks are persisting offshore Townsville and the Whitsundays. The COTS Control Program is continuing to suppress outbreaks and protect coral across hundreds of reefs.
Reef management
As the lead managers of the Reef, we are working closely with our partners to monitor conditions across the Marine Park during these high-risk summer months.
We also use a range of management actions to support and build Reef resilience, including enforcing compliance with our zoning plan and ensuring people enjoy the Reef in a responsible way.
The Marine Monitoring Program informs managers and the wider community about the condition of inshore corals and seagrass, and the effects of poor water quality from land-based runoff on these ecosystems.
The program is coordinated by the Reef Authority, with key partners including AIMS, James Cook University—TropWater, the Cape York Water Partnership, and University of Queensland.
You too can help by reporting any incidents through the Eye on the Reef app, which is available for download on Google Play or Apple Store.
Reef Health update | 12 February 2025
North Queensland continued to be inundated by heavy rainfall over the past week, with many local communities already recording their highest monthly rainfall for February. Rainfall has seen many rivers reach major flood levels.
The increased wind and cloud cover from this low-pressure weather system have cooled temperatures across most of the Marine Park.
The impacts of this weather event on the Marine Park are still being assessed, including any changes to the Reef’s water quality through floodwaters and freshwater intrusions.
Temperatures
Forecasts indicate sea surface temperatures will remain 0.5-to-1-degree Celsius above average for most of the Marine Park, with higher temperatures expected in the Far Northern region.
Rainfall
Very significant rainfalls have occurred over the catchment over the past week due to the monsoon trough across north Queensland.
Above average rainfall is likely to continue across the north over the next three months.
Reef health
Over the past fortnight, 154 Reef Health Impact Surveys (RHIS) were conducted across 20 reefs in the Marine Park. These surveys provide a detailed snapshot of reef health, including a breakdown of habitat and impact assessment.
Reefs surveyed in the Northern Region, the Cairns–Cooktown area, showed 1–10 per cent bleaching prevalence, while those in other regions were less affected by heat stress. No data was available for reefs above Cooktown in the Far Northern Region.
The Marine Monitoring Program is out sampling sites in the Mackay−Whitsundays, Burdekin, and Wet Tropics areas following the heavy rainfall over the past few weeks.
Aerial imagery including recent drone footage collected by the Crown-of-thorns starfish control program is being used to assess flood plume extent.
Crown-of-thorns starfish outbreaks are present in the Southern Region (Swain Reefs) and the Northern ‘initiation zone’ (Port Douglas to Lizard Island), with isolated outbreaks near Townsville and Whitsundays.
The Crown-of-thorns Starfish Control Program is prioritising reducing spawning populations in the "initiation zone" to prevent further spread of this coral-eating species, with concern the increasing population in this area may trigger waves of secondary outbreaks.
Reef management
As the lead managers of the Reef, we are working closely with our partners to monitor conditions across the Marine Park during these high-risk summer months.
We also use a range of management actions to support and build Reef resilience, including enforcing compliance with our zoning plan and ensuring people enjoy the Reef in a responsible way.
You too can help by reporting any incidents through the Eye on the Reef app, which is available for download on Google Play or Apple Store.
Reef Health update | 05 February 2025
The heavy rainfall across north Queensland has caused major flooding in some parts, which has severely impacted local communities – our thoughts are with you all.
The severe weather system has generated heavy rainfall, cloud cover and wind, which may provide some cooling benefits across much of the Marine Park. Flooding and resulting freshwater intrusion into the Marine Park may impact seagrass meadows and cause coral bleaching on some inshore coral reefs. This will be monitored using our extended network of partners undertaking standard assessments and reactive surveys.
Temperatures
Heat stress has continued to accumulate across the Reef, with Far North and Northern regions of the Great Barrier Reef exposed to above average sea surface temperatures for longer than the Central and Southern regions. Forecasts indicate sea surface temperatures may reduce over the next week, especially in the Northern and Far Northern regions as a result of the tropical low, however temperatures are still expected to exceed monthly averages by 0.5 to 1 degree Celsius.
Air temperatures have eased in the Great Barrier Reef catchments following the development and movement of the low-pressure system.
Rainfall
Very significant rainfalls have occurred over the catchment due to the slow-moving nature of the tropical low and monsoon trough over north Queensland.
Over the next three months, rainfall is likely to be above average across much of northern and eastern Australia, with the likelihood of above average rainfall exceeding 80% in parts of northern and central Queensland.
Reef health
Sixty-three Reef Health Impact Surveys (RHIS) were conducted across 10 reefs in the Marine Park over the past fortnight. These surveys recorded a low prevalence of coral bleaching, mostly in the Central region.
The Marine Monitoring Program is reviewing its flood response in the Mackay−Whitsundays, Burdekin, and Wet Tropics regions due to the recent heavy rainfall. While road closures are currently impacting access to sampling sites, the team is ready to conduct surveys once it is safe to do so. Satellite imagery will be continually reviewed to measure the extent and exposure of flood plumes entering the Marine Park.
Crown-of-thorns starfish outbreaks are present in the Southern Region (Swain Reefs) and the Northern ‘initiation zone’ (Port Douglas to Lizard Island), with isolated outbreaks near Townsville and the Whitsundays.
The Crown-of-thorns Starfish Control Program is prioritising reducing spawning populations in the "initiation zone" to prevent further spread of this coral-eating species, with concern the increasing population in this area may trigger waves of secondary outbreaks.
Reef management
As the lead managers of the Reef, we are working closely with our partners to monitor conditions across the Marine Park during these high-risk summer months.
We also use a range of management actions to support and build Reef resilience, including enforcing compliance with our zoning plan and ensuring people enjoy the Reef in a responsible way.
You too can help by reporting any incidents through the Eye on the Reef app, which is available for download on Google Play or Apple Store.
Reef Health update | 29 January 2025
An increase in activity of the monsoon trough across northern Australia is expected to provide a reprieve from hot weather over the coming weeks and could potentially mitigate the impacts of higher sea surface temperatures across the Reef.
Monsoonal conditions bringing wind and rain will potentially reduce elevated sea surface temperatures across the northern and central regions of the Great Barrier Reef Marine Park.
Heat stress is currently highest in the Far North of the Marine Park, progressively declining toward the south, with the Southern region showing the lowest level of accumulated heat stress.
Temperatures
Despite promising forecasts, sea surface temperatures are currently between 1 to 2 degrees Celsius above average, with the highest temperature anomalies recorded in the Northern and Central regions. These higher-than-average temperatures are expected to persist throughout summer, with the peak in March – although local weather conditions across the region will continue to influence outcomes for the Reef during this period.
Air temperatures continue to be above average throughout the Great Barrier Reef catchments but are also expected to ease with the onset of the low-pressure system across the region.
Rainfall
Above average rainfall is expected to continue throughout January. Rainfall is likely to be above average across much of northern and eastern Australia, with the likelihood of above average rainfall exceeding 80% in parts of northern and central Queensland for February through to April.
Reef health
Forty-two reefs were surveyed across the Marine Park over the past fortnight with low prevalence of coral bleaching reported, mainly in the Central and Northern regions.
Crown-of-thorns starfish outbreaks remain the most severe in the Southern Region (Swain Reefs) and the Northern ‘initiation zone’ (Port Douglas to Lizard Island), with isolated outbreaks offshore Townsville and the Whitsundays.
The Crown-of-thorns Starfish Control Program is prioritising reducing spawning populations in the "initiation zone" to prevent further spread of this coral-eating species, with concern the increasing population in this area may trigger waves of secondary outbreaks.
Reef management
As the lead managers of the Reef, we are working closely with our partners to monitor conditions across the Marine Park during these high-risk summer months.
We also use a range of management actions to support and build Reef resilience, including enforcing compliance with our zoning plan and ensuring people enjoy the Reef in a responsible way.
You too can help by reporting any incidents through the Eye on the Reef app, which is available for download on Google Play or Apple Store.
Reef Health update | 22 January 2025
Heatwave conditions have continued across Queensland over the past week contributing to heat stress on the Reef.
The persistent hot weather means we are seeing heat building up across the Reef, with more heat accumulating in the Far Northern and Northern regions, and less in the Central and Southern regions.
However, it’s important to note that local and regional factors will play a crucial role in determining the health of the Reef. Conditions such as water quality, currents, and local weather patterns, will ultimately influence the Reef’s outcomes this summer.
Temperatures
Air temperatures across the Marine Park have continued to be above average as heatwave conditions persist across most of the catchments.
Sea surface temperatures remain between 1−1.5°C above average across most of the Marine Park, with the highest temperature anomalies recorded in the Northern Region. These higher-than-average temperatures are expected to persist throughout summer, with the peak in March.
Recent data shows 2024 was the third hottest year on record for average sea surface temperatures on the Reef.
Rainfall
Above average rainfall is expected to continue throughout January.
Reef health
Forty-one reefs were surveyed across the Marine Park in the past week with a few isolated cases of coral bleaching — reported, mainly in the Central Region. Limited data were gathered from the Northern Region over this time.
Crown-of-thorns starfish numbers are highest in the Southern Region (Swain Reefs) and the Northern ‘initiation zone’ (Port Douglas to Lizard Island), with isolated outbreaks offshore Townsville and the Whitsundays.
The Crown-of-thorns Starfish Control Program is prioritising reducing spawning populations in the "initiation zone" to prevent further spread of this coral-eating pest species, with concern the increasing population in this area may trigger waves of secondary outbreaks.
Reef management
As the lead managers of the Reef, we are working closely with our partners to monitor conditions across the Marine Park during these high-risk summer months.
We also use a range of management actions to support and build Reef resilience year-round, including enforcing compliance with our zoning plan and ensuring people enjoy the Reef in a responsible way.
You too can play your part to help protect our iconic Reef. Make sure you know your zones before heading out into the Marine Park and follow safe anchoring practices. Our compliance teams are out in force over the summer so do your bit to protect the Reef, and don’t hook a fine!
Reef Health update | 15 January 2025
Heatwave conditions and above average rainfall have continued across much of the Marine Park over the past week contributing to heat stress on the Reef.
El Niño–Southern Oscillation (ENSO) patterns are consistent with a developing La Niña which is unusual for this time of year.
It’s important to note that local and regional factors will play a crucial role in determining the health of the Reef. Specific conditions in the area, such as water quality, currents, and local weather patterns, will ultimately influence the Reef’s outcomes this summer.
Temperatures
Air temperatures across the Marine Park have been above average as heatwave conditions persist across most of the catchment.
Sea surface temperatures were between 0.8−1.2°C above average across most of the Marine Park, with the highest temperature anomalies recorded in the Northern Region. These are forecast to persist for the rest of the week, with temperature anomalies expected to peak in March.
Rainfall
Rainfall totals ranged from 50 to 100mm across the Marine Park catchment, with isolated areas receiving more than 100mm.
Minor flooding has been reported in some rivers in the Central and Southern region catchments, but there are no reports of flood plumes in the Marine Park.
Above average rainfall is expected to continue throughout January.
Reef health
A few cases of minor coral bleaching have been reported in the Marine Park in the past week, mostly in the Central and Northern regions.
Crown-of-thorns starfish numbers are highest in the Southern Region (Swain Reefs) and the Northern ‘initiation zone’ (Port Douglas to Lizard Island), with isolated outbreaks offshore Townsville and the Whitsundays.
The Crown-of-thorns Starfish Control Program is prioritising reducing spawning populations in the "initiation zone" to prevent further spread of this coral-eating pest species.
Reef management
As the lead managers of the Reef, we are working closely with our partners to monitor conditions across the Marine Park during these high-risk summer months.
We also use a range of management actions to support and build Reef resilience year-round, including enforcing compliance with our zoning plan and ensuring people enjoy the Reef in a responsible way.
Our Marine Park compliance patrols have been out in force over the holiday period, particularly at known illegal fishing hotspots, to ensure Marine Park users are doing the right thing to minimise additional stress to the Great Barrier Reef.
You can do your bit to help protect this World Heritage-listed natural wonder. Make sure you know your zones before heading into the Marine Park and report what you see through the Eye on the Reef App.
Reef Health update | 18 December 2024
The summer has commenced with global sea surface temperatures remaining at near record highs, and forecast models predicting elevated ocean temperatures across the Great Barrier Reef Marine Park over the coming months.
This forecast indicates a risk of exposure to thermal stress building across the Reef during summer, and we are starting to see it now.
The National Oceanic and Atmospheric Administration (NOAA) Coral Reef Watch has the Central and Northern regions of the Marine Park on a “bleaching warning” with accumulated heat stress of 1 degree heating week, which means coral bleaching is possible, particular for sensitive coral species.
From December to March, there is a high chance of unusually high rainfall for catchments adjacent to the Reef, particularly Cape York Peninsula, with above average falls predicted for all other Marine Park catchment areas.
It’s important to note that local and regional factors will play a crucial role in determining the health of the Reef. The specific conditions in the area, such as water quality, currents, and local weather patterns, will ultimately influence the Reef’s outcomes this summer.
Temperatures
Sea surface temperatures remain high across the Marine Park, with most areas currently 1-1.5°C above the average for December.
Rainfall
Over the past few weeks, rainfall in the Peninsula, North Tropical Coast, and Tablelands (west of Cairns) districts exceeded 200 mm. However, the Bureau has reported no significant river flooding freshwater intrusion, or sediment runoff into Reef waters.
Reef health
From mid-November to December 12, 2024, 739 Reef Health Impact Surveys (RHIS) were conducted across 79 reefs in the Marine Park. These surveys, carried out by trained and experienced managers and researchers, are designed to quickly assess the condition of the reefs.
Low levels of coral bleaching were observed on some of the surveyed reefs, mainly in the Central and Northern regions of the Marine Park. Sea surface temperatures are currently high enough to cause heat stress to corals, increasing the risk of coral bleaching during this time of year.
Crown-of-thorns starfish populations continue at outbreak densities at the Swain Reefs in the Marine Park’s Southern Region, as well as on offshore reefs between Port Douglas and Lizard Island. Isolated outbreaks also persist on several reefs offshore Townsville and the Whitsunday Islands in the Central Region.
The outbreak of this starfish between Port Douglas and Lizard Island, an area known as the ‘initiation zone’, is concerning for its potential to ‘seed’ secondary outbreaks on downstream reefs further south.
Late December is the starfish’s breeding season. The control program’s focus during this time is reducing its population in this initiation zone to reduce the risk to reefs further south.
Reef management
Reef protection continues to be a year-round activity, but our focus is heightened over summer when the Reef is more at risk from cumulative impacts including elevated sea surface temperatures, cyclones and freshwater inundating the marine environment.
We are working closely with our partners to protect and strengthen the resilience of the Reef through a range of management actions, including controlling 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 help do your bit in protecting this World Heritage-listed natural wonder by knowing the zoning rules.
Reef Health update | 11 December 2024
The Reef Authority continues to monitor conditions on the Reef and work with its science, Traditional Owner and management partners to prepare for the 2024–25 summer.
The summer has commenced with global sea surface temperatures remaining at near record highs, and forecast models predicting elevated ocean temperatures across the Great Barrier Reef Marine Park over the coming months.
This forecast indicates a risk of thermal stress building across the Reef during summer.
From December to March, there is a high chance of unusually high rainfall for parts of the Reef, particularly the Cape York peninsula, with above average predictions for all other Marine Park catchment areas.
Air temperatures are also expected to be warmer than average throughout January to March.
Overall, the Bureau of Meteorology forecasts a wet and warm December, and then drier and warm conditions over the Great Barrier Reef for January. An average number of cyclones is forecasted typically four across the region. However, these cyclones are likely to be more intense due to warmer-than-average sea temperatures.
November and early December conditions
Temperatures
Sea surface temperatures throughout the Northern and Central regions were about 0.5°C above average during November, and up to 0.8°C above average in the Southern Region. Currently, sea surface temperatures are 0.5°C above average for most of the Reef, but up to 1°C above average in the Far Northern and Southern regions.
Rainfall
November saw lower than average rainfall for most Reef catchments. December is expected to bring higher than average rainfall particularly in the Northern regions.
Reef health
During November 559 Reef Health Impact Surveys were conducted across 72 reefs in the Marine Park, recording a low incidence of coral bleaching and coral disease mainly from the Central Region, between Townsville and the Whitsundays. These comprehensive surveys, conducted by trained and experienced managers and researchers, are designed to enable rapid assessment of reef condition.
Crown-of-thorns starfish populations continue at outbreak densities at the Swains Reef in the Marine Park’s Southern Region, as well as on offshore reefs between Port Douglas and Lizard Island. Isolated outbreaks also persist on several reefs offshore Townsville and Whitsunday in the Central Region.
The outbreak of this starfish between Port Douglas and Lizard Island, an area known as the ‘initiation zone’, is concerning for its potential to ‘seed’ secondary outbreaks on downstream reefs further south.
In the lead up to the starfish’s breeding season, typically late December at the start of the tropical wet season, the control program’s focus is reducing its population in this initiation zone to suppress the buildup of the primary outbreak.
Reef management
Last week our annual summer workshop was held with management partners, Traditional Owners, scientists, tourism, and Reef-dependent industry representatives. Workshop participants focused on current conditions and the latest environmental forecast modelling to understand the likely outlook for summer, and to plan a coordinated approach for the months ahead.
It is too early to tell exactly what summer will bring, and local and regional conditions will ultimately influence Reef health outcomes.
Reef protection continues to be a year-round activity. We are working with our partners to protect and strengthen the resilience of the Reef through a range of management actions, including controlling 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 | November 2024
The Bureau of Meteorology is predicting a warm 2024–25 summer season as a result ongoing high sea surface temperatures.
The Bureau, together with CSIRO, recently released the latest State of the Climate 2024 report, which looks at long-term climate trends in Australia.
- The report found:
- Sea surface temperatures, ocean heat content, and acidification in the Marine Park have all been rising in recent decades.
- Since 1900, sea surface temperatures have increased by 1.08°C, contributing to more frequent extreme heat events, both on land and in the ocean.
- The world's oceans have absorbed over 90 per cent of the extra energy from greenhouse gases.
The report highlights the importance of the work we do to build the resilience on the Great Barrier Reef, including programs such as the Crown-of-thorns starfish Control Program which is doing critical work to reduce outbreaks of the starfish to protect coral cover.
On a positive note, it’s coral spawning season — a time of regeneration for the Reef, as spawning corals pass on heat-tolerant genes, helping the Reef adapt to warmer waters.
October conditions
During October, sea surface temperatures were about 0.5°C above average across the Marine Park.
Rainfall was slightly below average across Queensland, with low chances of extreme rain in November.
A total of 497 Reef Health Impact Surveys were conducted across 41 reefs in the Marine Park, showing minor coral bleaching in some areas, likely linked to earlier mass bleaching this year. Coral recovery and mortality remains varied across the Reef.
There were no reports of disease or physical damage (such as that caused by anchors) during these surveys.
Crown-of-thorns starfish outbreaks continue to be an issue at some reefs, particularly in areas like Swain Reefs and offshore Port Douglas, and isolated outbreaks are ongoing on several reefs offshore Townsville and the Whitsundays.
During coral spawning, the focus of the Crown-of-thorns starfish control program is to reduce starfish populations to protect the Reef's recovery.
Reef management
With summer approaching, the Reef is more vulnerable to extreme weather like cyclones and heatwaves.
We’re working closely with partners including the Queensland Parks and Wildlife Service through the Reef Joint Field Management Program, as well as the tourism industry and scientific organisations such as the Australian Institute of Marine Science to monitor the Reef 24/7.
Over the past month, we've been working with the tourism industry, running Eye on the Reef training which teaches operators how to gather important data on Reef health, which we use year-round to monitor conditions.
The training will continue this month, including training a new cohort of Master Reef Guides.
Our year-round management actions are geared towards building and supporting Reef resilience, including enforcing compliance with the Reef’s zoning plan and ensuring people are enjoying the Reef in a responsible way.
Stay up-to-date with what’s happening across the Reef by following our social channels and downloading the Eye of the reef app to let us know what you see in the Marine Park.
Reef Health update | October 2024
Global sea-surface temperatures remain above average across most of the planet.
Sea-surface temperatures across the Great Barrier Reef Marine Park are around 0.6°C higher than average for this time of year but these temperatures are not at levels that typically cause impacts such as coral bleaching.
Sea-surface temperatures across the Marine Park are expected to remain from 0.4 to 1.2°C above average from October to December. However, local weather conditions will have a key influence on sea surface temperatures during the summer.
The El Niño–Southern Oscillation weather pattern’s neutral condition remains, and the Bureau of Metrology predicts these neutral conditions to continue over the summer.
Reef Health summary for September
This Reef Health update is based on data collected during September, 2024.
In September, 348 Reef Health Impact Surveys (RHIS) were conducted across 31 reefs in the Marine Park.
Reef Health Impact Surveys are a quantifiable survey method used mostly by the Reef Authority, Queensland Parks and Wildlife Service and researchers as well as trained tourism operators.
Most reefs surveyed showed no signs of coral bleaching, with very few cases of minor bleaching reported in each region. Any coral bleaching observed is not likely related to current sea-surface temperatures as they are under the levels that would usually cause coral bleaching. The surveys also found minor damage (for example, from anchor damage) on some corals but no signs of disease in all regions of the Marine Park.
There was average or below average rainfall reported across all Reef catchments in September.
The highest known crown-of-thorns starfish outbreak densities continue at some reefs in the offshore Southern Region (Swain Reefs) and isolated outbreaks remain on several reefs offshore Townsville and Whitsunday in the Central Region.
The Crown-of-thorns starfish Control Program is in operation, helping us to target those veracious coral predators so we can support the recovery of coral ecosystems and their resilience into the future.
Reef management
The Reef Authority collaborates with science and management institutions to maintain a contemporary understanding of Reef health and the impacts of climate change on the World Heritage Area.
The Australian Institute of Marine Science, the Bureau of Meteorology, CSIRO, and other research institutions continue to deliver monitoring and research that documents the long-term trend of Reef conditions and climate patterns. This includes multiple monitoring programs under the Reef 2050 Integrated Monitoring and Reporting Program.
During the summer months, the Reef is more vulnerable to extreme weather events including cyclones, marine heatwaves and flooding – the effects of which are compounded by climate change.
As we move into the warmer months, there is a lot of work being done with our partners to prepare for summer.
We are also preparing for the upcoming coral spawning, which only occurs a few nights of the year. During this phenomenal event, millions of bundles of coral sperm and eggs are released into the ocean allowing for mass reproduction—a positive sign for Reef renewal and regeneration.
You can do your bit to help protect the Reef by following a few simple steps:
- Use public moorings where available and do not anchor within no-anchoring areas – they are there to protect the coral.
- Where possible, anchor in sand or mud away from corals and other fragile marine environments. Suitable areas often show up as flat and smooth on your sounder.
- Never wrap anchor rope or chain around bommies or large coral heads.
- If anchoring overnight, anchor before nightfall and double-check the swing room.
- Use your sand anchor and reef pick appropriately to minimise damage.
- Motor towards the anchor when hauling it in and retrieve the anchor when the line is vertical.
- If the anchor is caught on a reef, free it by hand wherever possible.
- Do not force the anchor free by motoring forward.
- Keep watch to make sure the anchor isn’t dragging.




