Reef Health Updates

Great Barrier Reef Marine Park Authority
  • 0.0 (0)
  • NATURAL SCIENCES

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.

  1. 16 HRS AGO

    Reef health update | 30 April 2026

    Reef health update | 30 April 2026 Sea surface temperatures continue to ease across the Marine Park, and with the changing of seasons we are seeing the last of the turtle hatchlings and seabird nesting, as humpback and Minke whales begin arriving in the Reef’s breeding grounds. Queensland’s wet season is also coming to an end, with rainfall over the summer months among the highest levels recorded since 1900. Temperature Sea surface temperatures declined slightly, dropping by 0.3–0.5°C across the Marine Park, temperatures remain 0.4–0.5°C above the long-term April average. Rainfall Weekly rainfall totals were below average across most Marine Park catchments, with less than 50mm recorded. Reef health Over the past week, 43 Reef Health Impact Surveys were conducted across six reefs. In the Northern region, four reefs were surveyed. Two recorded low coral bleaching, and three showed low to moderate coral damage. Higher bleaching levels in the Northern region are likely linked to prolonged heat exposure over summer combined with earlier flood plume impacts. Coral damage in the Far Northern and Northern regions is likely the result of storm impacts from Ex-Tropical Cyclone Narelle. In the Central region, one reef was surveyed with no coral bleaching or damage recorded. In the Southern region, one reef was surveyed with no coral bleaching or damage recorded. No coral disease was observed over the past week. Additional Eye on the Reef observations from across the Marine Park reported coral bleaching on 16 of 20 reefs surveyed. Crown-of-thorns starfish control The Crown-of-thorns Starfish Control Program continues to manage ongoing outbreaks across the Marine Park, with updates shared in the first weekly Reef Health Update of each month.

    2 min

  2. 23 APR

    Reef health update | 23 April 2026

    Reef health update | 23 April 2026 Ex-Tropical Cyclone Maila crossed Cape York Peninsula as a tropical low on 15 April, bringing moderate rainfall of up to 50mm to coastal Cape York and Wet Tropics catchments. Sea surface temperatures continue to ease, and with the changing of seasons we are now seeing the first humpback whales arriving in the Marine Park, as they migrate from Antarctic waters to their traditional breeding grounds. A recent Reef Authority and Queensland Parks and Wildlife Service voyage in the Far Northern region completed 75 surveys across five reefs, providing early insights into cyclone impacts. Reefs closest to Ex-Tropical Cyclone Narelle’s path showed moderate to severe structural damage, while more sheltered reefs to the south of the cyclone’s path recorded low to minimal impacts. Damage was generally higher on reef areas exposed to incoming waves. The team also observed island vegetation damage, localised erosion, and coral colonies washed up on beaches or cays, along with low levels of coral bleaching on two reefs. Some planned sites could not be accessed due to weather conditions associated with Ex-Tropical Cyclone Maila; however, Crown-of-thorns starfish control teams are scheduled to return to these areas and are expected to access these sites and undertake surveys to improve our understanding of Reef health impacts. Temperature Sea surface temperatures declined slightly this week by around 0.1°C across the Marine Park. Temperatures remain 0.5–0.7°C above the long-term April average. Rainfall Weekly rainfall totals were average across most of the Marine Park catchments over the past week. Weekly totals reached up to 150mm in Cape York and the Wet Tropics, and up to 100mm in the Mackay–Whitsunday region. Reef health Over the past week, 225 Reef Health Impact Surveys were conducted across 22 reefs. In the Far Northern region, five reefs were surveyed. Two recorded low bleaching, and all showed low to severe coral damage. In the Northern region, five reefs were surveyed, with bleaching ranging from low to very high (up to 90%). Three reefs also recorded low to severe coral damage. Higher bleaching levels in the Northern region are likely linked to prolonged heat exposure over summer combined with earlier flood plume impacts. Coral damage in the Far Northern and Northern regions is likely the result of storm impacts from Ex-Tropical Cyclone Narelle. In the Central region, 11 reefs were surveyed. Eight showed low to moderate bleaching, and four recorded low coral damage. In the Southern region, one reef was surveyed, showing moderate bleaching and low coral damage. Coral disease was recorded on six reefs across the Marine Park. Additional Eye on the Reef observations from across the Marine Park reported coral bleaching on 12 of 17 reefs surveyed. Crown-of-thorns starfish control The Crown-of-thorns Starfish Control Program continues to manage ongoing outbreaks across the Marine Park, with updates shared in the first weekly Reef Health Update of each month.

    2 min

  3. 16 APR

    Reef health update | 16 April 2026

    Sea surface temperatures continued to cool, dropping by a further 0.4–0.6°C this week across the Marine Park. Ex-Tropical Cyclone Maila has weakened and was downgraded to a tropical low on 11 April. The system crossed the Cape York Peninsula on 15 April, bringing moderate to heavy rainfall in some areas. Encouragingly, the National Oceanic and Atmospheric Administration (NOAA) has now reduced the Coral Reef Watch Bleaching Alert Status to no stress conditions across the entire Great Barrier Reef Marine Park, following further drops in sea surface temperatures - reflecting heat stress easing across the Marine Park. Since Ex-Tropical Cyclone Narelle, reports from the Eye on the Reef network have identified coral damage on some outer reefs in the Northern region. In response, the Reef Authority and Queensland Parks and Wildlife Service will carry out targeted Reef Health Impact Surveys in the Far Northern region in the coming weeks, weather permitting. Temperature Despite the recent cooling, sea surface temperatures remain 0.4–0.5°C above the long-term April average. The Far Northern and Northern regions are still experiencing the effects of accumulated marine heatwave exposure from earlier in summer, which may cause bleaching in some coral species. Rainfall Weekly rainfall totals were below average across most of the Marine Park catchments over the past week. Reef health Over the past week, 42 Reef Health Impact Surveys were conducted across seven reefs in the Marine Park. In the Northern region, six reefs were surveyed, with coral bleaching ranging from low (1–10%) to very high (61–90%). These bleaching patterns in the Northern region are likely linked to heat stress and flood plume impacts that accumulated over the summer. Coral damage was also recorded on four of the six Northern reefs surveyed, ranging from low to severe, likely caused by storm impacts from Ex-Tropical Cyclone Narelle. Two reefs in the Northern region also recorded moderate levels of coral disease. Limited surveys in the Far Northern region mean the full extent of coral bleaching is still emerging, but elevated levels are expected given its prolonged exposure to above-average sea surface temperatures. In the Southern region, one reef was surveyed and no bleaching was recorded. Additional Eye on the Reef observations from across the Marine Park reported bleaching on 16 of 32 reefs surveyed across the Marine Park. Crown-of-thorns starfish control The Crown-of-thorns Starfish Control Program continues to manage ongoing outbreaks across the Marine Park, with updates shared in the first weekly Reef Health Update of each month.

    2 min

  4. 9 APR

    Reef health update | 9 April 2026

    Reef health update | 9 April 2026 Sea surface temperatures continued to cool this week, dropping by 0.2–0.4°C across most of the Marine Park. Tropical Cyclone Maila (37U) has now formed in the Solomon Sea and has rapidly intensified into a Category 5 system. Current Bureau of Meteorology forecasts show the system tracking into the Coral Sea, with a likely coastal crossing near Cape York Peninsula this weekend or early next week. Maila is expected to bring localised heavy rainfall, increasing the risk of flood plumes in the Marine Park and possible damage to coral and seagrass habitats from strong waves. Encouragingly, coral bleaching alert levels have eased. The USA’s National Oceanic and Atmospheric Administration (NOAA), which monitors ocean temperatures globally, has downgraded the Northern, Central, and Southern regions to no stress conditions, following further drops in sea surface temperatures - reflecting heat stress easing across the Marine Park. Temperature Despite recent decreases in sea surface temperatures, they remain around 0.6–0.7°C above the long-term April average. The Far Northern and Northern regions are still experiencing the effects of accumulated marine heatwave exposure from earlier in summer, which may cause bleaching in some coral species. Rainfall Weekly rainfall across most catchments was average or below average, with totals generally under 100mm except for the Wet Tropics region receiving up to 150mm. Rainfall in March was higher than usual across most Marine Park catchments, with the Cape York, Fitzroy and Burnett–Mary catchments having some of the highest March rainfalls recorded. Reef health Over the past week, 19 Reef Health Impact Surveys were completed across five reefs in the Marine Park. In the Northern region, four reefs were surveyed with high (31–60%) to very high (61–90%) coral bleaching recorded on three reefs. These bleaching patterns in the Northern region are likely linked to heat stress accumulated over the summer combined with earlier flood plume impacts. All four reefs surveyed in the Northern region also showed severe coral damage, likely caused by storm impacts associated with Ex-Tropical Cyclone Narelle. Limited surveys in the Far Northern region mean the full extent of coral bleaching is still emerging, but higher levels are expected given its prolonged exposure to above-average sea surface temperatures. In the Central region, one reef was surveyed and no bleaching was recorded. Additional Eye on the Reef observations from across the Marine Park reported bleaching on 11 of 19 reefs. No coral disease was recorded during the period. Crown-of-thorns starfish control As of 31 March 2026, the Crown-of-Thorns Starfish Control Program and Reef Joint Field Management Program response teams have surveyed and, where needed, culled starfish on 187 reefs this financial year. Of these reefs: Crown-of-thorns starfish are at sustainable levels on 80 reefs (43%). Active culling is underway on 60 reefs (32%) to suppress outbreaks. Starfish have been detected on 47 reefs (25%), and these reefs will be targeted for culling based on priority and actioned when operationally feasible. The program uses a science-based prioritisation process to focus effort on reefs with high ecological and economic value, with the aim of maximising coral protection.

    3 min

  5. 2 APR

    Reef health update | 2 April 2026

    Sea surface temperatures continue to ease across the Marine Park this week, dropping by around 0.1–0.2°C. Heavy rainfall from ex-Tropical Cyclone Narelle caused a major flood in the Far Northern region, with the Pascoe River reaching 19.3 metres - the highest level recorded in more than 50 years and likely a one-in-200-year event. The flood plume may affect nearby ecosystems like seagrass meadows and inshore reefs by lowering salinity and increasing exposure to sediments, nutrients, and pesticides. The Bureau of Meteorology forecasts a tropical low (37U) may form near the Solomon Islands by Thursday, with a moderate to high chance of developing into a cyclone over the weekend. At this stage, it is expected to stay away from the Queensland coast over the next week. Temperature Despite recent decreases in sea surface temperatures, they remain around 0.7°C above the long-term monthly average. The Far Northern and Northern regions are still experiencing the effects of accumulated marine heatwave exposure from earlier in summer, which may cause bleaching in some corals species. Rainfall Weekly rainfall totals were mostly average or below average across the Marine Park catchment areas during the past week, with up to 100mm of rain recorded over the reporting period. Reef health Over the past week, 43 Reef Health Impact Surveys were conducted across seven reefs in the Marine Park. In the Northern region, five reefs were surveyed with coral bleaching ranging from low (1–10%) to very high (61–90%). In the Central region, two reefs were surveyed and no coral bleaching was observed. Limited surveys in the Far Northern region mean the full extent of coral bleaching is still emerging, but higher levels are expected given its prolonged exposure to above-average sea surface temperatures. Additional Eye on the Reef observations from across the Marine Park reported bleaching on 9 out of 24 reefs. High levels of bleaching in the Northern region may be linked to prolonged heat exposure and impacts from flood plumes. Surveys also recorded moderate to extreme coral damage on three Northern reefs, likely from storm impacts related to Ex-Tropical Cyclone Narelle. One Central reef showed low damage from storms activity, and one reef had moderate coral disease. Crown-of-thorns starfish control The Crown-of-thorns Starfish Control Program continues to manage ongoing outbreaks across the Marine Park, with updates shared in the first weekly Reef Health Update of each month.

    2 min

  6. 26 MAR

    Reef health update | 26 March 2026

    We are thinking of communities in the Far Northern region affected by Tropical Cyclone Narelle. Tropical Cyclone Narelle passed through the Far Northern region of the Marine Park as a Category 5 system and crossed the Queensland coast as a Category 4 on 20 March. The cyclone generated intense winds and strong wave action along its track in the Far Northern Region, with modelling also indicating wide-spread high wave action in the Northern region, particularly across offshore reefs. The extent of damage will be assessed in the coming weeks. The El Niño–Southern Oscillation (ENSO) climate pattern, La Niña, continues to weaken, and conditions are expected to return to a neutral phase in early autumn. However, forecasts suggest that by winter, the system may shift into an El Niño phase, which often brings warmer and drier conditions to much of Australia. Temperature Sea surface temperatures continue to fall across the Marine Park, with the largest drop (0.8°C) recorded in the Northern region, however they remain around 0.6°C above the long-term monthly averages. Despite recent decreases in sea surface temperatures, some reefs in the Far Northern and Northern regions have accumulated heat stress exposure that can cause some coral species to bleach. Rainfall From 16–22 March, localised heavy rainfall was recorded in the Cape York and Wet Tropics catchments as Tropical Cyclone Narelle moved through the region. Weekly rainfall totals ranged from 200–450mm, with some locations receiving more than 100–200mm in a single day. Flood warnings are active across parts of the Cape York catchment, and significant flooding has been reported in the Pascoe River, which is currently at record levels. Reef health Over the past week, 67 Reef Health Impact Surveys were completed across nine reefs in the Northern (between Innisfail and just above Cooktown), Central (between Mackay and Innisfail) and Southern regions (between Bundaberg and Mackay). Coral bleaching in the Northern region varied from moderate (11–30%) to very high (61–90%). Of the five reefs surveyed, one reef also showed signs of coral mortality. These impacts are likely linked to a combination of exposure to ongoing heat stress and recent floodwaters. In the Central region one reef was surveyed, with no bleaching recorded. In the Southern region 3 reefs recorded medium (11–30%) coral bleaching prevalence. Additional Eye on the Reef observations from across the Marine Park reported bleaching on 9 of 20 surveyed reefs. Coral damage was recorded on 6 reefs, and coral disease was observed on 3 reefs. Crown-of-thorns Starfish Control The Crown-of-thorns Starfish Control Program continues to manage ongoing outbreaks across the Marine Park, with updates shared in the first weekly Reef Health Update of each month.

    2 min

  7. 19 MAR

    Reef health update | 19 March 2026

    Tropical Cyclone Narelle (currently Category 5) has developed in the Coral Sea and is forecast to decrease to a Category 4 before crossing the Far Northern region of the Marine Park and making landfall on Friday. The system is expected to bring strong wind and wave action and heavy rainfall, which are likely to damage some reefs and increase the likelihood of freshwater runoff into the Marine Park. Sea surface temperatures have eased slightly over the past week, particularly in the Northern region (between Innisfail and just above Cooktown), while remaining relatively stable elsewhere. Encouragingly, coral bleaching alert levels have eased in recent days. The USA’s National Oceanic and Atmospheric Administration (NOAA), which monitors ocean temperatures globally, has downgraded the Far Northern and Northern regions to bleaching watch status following a drop in sea surface temperatures. Most other areas of the Marine Park are expected to return to no heat stress conditions. Temperature Temperatures are still slightly above the long-term monthly average for March across the Marine Park. The Far Northern (between Cape York and north of Cooktown) region is around 0.6°C above average, the Northern region (between Innisfail and just above Cooktown) around 1.1°C above average, and the Central (between Mackay and Innisfail) and Southern (between Bundaberg and Mackay) regions are around 1°C above average. Despite recent decreases in sea surface temperatures, some reefs in the Far Northern and Northern regions have accumulated exposure to heat stress that can cause some coral species to bleach. The most likely outlook from NOAA’s four-month forecast suggests heat stress will remain low to moderate across the Marine Park into winter. Rainfall From 9–15 March, heavy rainfall occurred in parts of the Burnett–Mary, Wet Tropics and Fitzroy catchments. Weekly totals ranged from 300–400mm in some areas, with several locations receiving more than 200mm in a single day. Rainfall in the Burnett–Mary catchment is among the highest on record for this time of year. Flooding has been reported in the Burnett River, and flood warnings remain in place across affected catchments. These conditions may lead to freshwater runoff into the Marine Park, which will continue to be monitored. Reef health Over the past week, 139 Reef Health Impact Surveys were completed across 19 reefs in the Far Northern, Northern and Central regions. In the Far Northern region, most surveyed reefs showed no to low coral bleaching, with a small number recording low to medium levels (1–30%), and no fully bleached coral or mortality observed. Coral bleaching in the Northern region varied, from moderate to very high (11–90%). Of the six reefs surveyed, four showed moderate to very high levels of coral bleaching. On these reefs, some corals were fully bleached, and two reefs also recorded small areas of coral mortality. These impacts are likely linked to a combination of exposure to recent heat stress and floodwaters. In the Central region, one reef recorded low levels of bleaching, with no fully bleached coral or mortality. Additional observations from Eye on the Reef monitoring programs reported coral bleaching on 9 of the 22 reefs surveyed. Coral damage was recorded on 12 reefs and coral disease on seven reefs. Crown-of-thorns starfish control The Crown-of-thorns Starfish Control Program continues to manage ongoing outbreaks across the Marine Park, with updates shared in the first weekly Reef Health Update of each month.

    2 min

  8. 12 MAR

    Reef Health Update | 12 March

    Reef health update - 12 March 2026 Sea surface temperatures eased slightly across the Marine Park over the past week. A tropical low crossed the Marine Park on 5–6 March. The system, together with a monsoon trough, brought heavy rainfall to the Cape York, Wet Tropics and Mackay–Whitsunday catchments. While this has helped keep temperatures down across the Reef, it also increases the likelihood of freshwater runoff entering the Marine Park. Another tropical low (34U) is forecast to develop in the Coral Sea off the East Coast of North Queensland. Forecasts continue to be monitored for any potential impacts to the Reef. Temperature Over the past week sea surface temperatures dropped from around 30°C to 29.1°C in the Far Northern region following recent weather systems. Sea surface temperatures in other regions also declined slightly, by around 0.1–0.4°C. Despite this, sea surface temperatures remain above the long-term average. The Far Northern, Central and Southern regions are currently around 0.7–0.9°C above average, while the Northern region remains around 1.3°C above average. As a result, heat stress continues to build across parts of the Marine Park. Some reefs in the Far Northern and Northern regions are experiencing conditions that may lead to bleaching in heat-sensitive corals. Rainfall From 2–8 March, heavy rainfall fell across the Cape York, Wet Tropics and Mackay–Whitsunday catchments. Weekly totals reached 300–400mm in some areas, with several locations receiving more than 200mm in a single day. Overall, rainfall for March so far is above to well above average in these regions. Heavy rainfall can increase the risk of freshwater runoff entering the Marine Park. Reef health Over the past week, 73 Reef Health Impact Surveys were completed across nine reefs in the Northern and Central regions. Monitoring shows that coral bleaching impacts remain varied across the reefs surveyed. Surveys on reefs in the Northern region recorded coral bleaching ranging from low levels (1–10%) to very high levels (61–90%). One reef in the Central region recorded medium bleaching levels (11–30%). Two reefs in the Northern region recorded small areas of fully bleached coral (less than 5%) and low levels of recent coral mortality (less than 3%). Coral damage was recorded on five reefs and coral disease was observed on four reefs. Additional observations from the Eye on the Reef monitoring programs also reported coral bleaching on eight of the 13 reefs surveyed. In the coming weeks, Reef Authority and Queensland Parks and Wildlife Service teams will carry out additional surveys in areas that have experienced high heat exposure to better understand impacts on reef health. Crown-of-thorns starfish control The Crown-of-thorns Starfish Control Program continues to manage ongoing outbreaks across the Marine Park, with updates shared in the first weekly Reef Health Update of each month. Our response and ongoing work Marine Monitoring Program teams and partners were also in the field sampling flood waters from the Annan and Endeavour rivers, with further sampling planned for the Normanby River in the coming week. The Reef Authority’s management decisions are informed by data collected by our teams on the water, including the Reef Joint Field Management Program and Crown-of-thorns Starfish Control Program as well as the collaborative efforts of researchers, tourism operators, contractors and partners. Management actions remain focused on supporting Reef resilience, including enforcing compliance with zoning rules and encouraging responsible use of the Marine Park. #reefhealth #lovethereef #greatbarrierreef

    2 min
See All (16)

About

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.

Information

  • Creator
    Great Barrier Reef Marine Park Authority
  • Years Active
    2K
  • Episodes
    16
  • Rating
    Clean
  • Copyright
    © GBRMPA 2026
  • Show Website
    Reef Health Updates