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.

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.

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.

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