Current conditions on the Reef
Each summer, we assess the health of reefs, as this part of the year poses a greater risk of coral bleaching, extreme weather and flooding.
Stressful conditions can lead to coral disease outbreaks, while poor water quality can also lead to greater numbers of coral eating crown-of-thorns starfish.
Summary of summer 2013-14
The Great Barrier Reef Region experienced neutral El Niño-Southern Oscillation conditions over summer 2013-14, according to the Bureau of Meteorology. On the scale of the whole Great Barrier Reef, these neutral conditions meant that there was an average number of cyclones, but relatively fewer impacts from coral bleaching and flood plumes than in recent years. However, most climate models show that conditions are now forecast to move towards an El Niño state (drier conditions) during the southern hemisphere winter.
- Sea surface temperatures remained near average from December 2013 to the end of April 2014, although current observations indicate the tropical Pacific Ocean is warming.
- Three cyclones (cyclone Dylan, Edna and Ita) occurred in the Great Barrier Reef Marine Park. The average number of cyclones for a summer season in this region is four. The most recent system, category 5 cyclone Ita, crossed the Reef at Lizard Island on Friday 11 April 2014 and made landfall at Cape Flattery as a category 4 system.
- Since October 2013, the catchment experienced low to average levels of rainfall, with some flooding and associated flood plumes in the northern region as a result of heavy rainfall from tropical cyclone Ita.
Coral reef health reports
Together with the Queensland Parks and Wildlife Service and the Eye on the Reef monitoring network, we carried out 1599 reef health and impact surveys across 117 reefs on the Great Barrier Reef between 1 December 2013 and 30 April 2014. Our reef health surveys are specifically designed to record recent instances of four main reef health impacts: coral bleaching, coral disease, coral damage and coral predation by crown-of-thorns starfish and the Drupella snail.
Most (89 per cent) of these surveys were completed in the Cairns-Cooktown region. Of the remainder, most were taken in the Mackay-Capricorn region. Survey effort was focused in the Cairns-Cooktown region during summer 2013-14 due to the ongoing responses to the crown-of-thorns starfish outbreak and the need to survey the impacts of tropical cyclone Ita.
Of all the surveys, 31.5 per cent recorded healthy coral reefs with no recent impacts, 37 per cent recorded one type of recent impact and another 31.5 per cent recorded more than one type of recent impact.
Low level coral bleaching was recorded in 16 per cent of surveys, and instances of coral disease were recorded in six per cent of surveys.
Due to the focus on surveying areas known to be impacted by crown-of-thorns starfish and cyclone damage this summer, approximately 45 per cent of surveys recorded either recent damage, predation by crown-of-thorns starfish, or both.
Most of the damage (61 per cent) was considered low severity and was attributed to a range of causes, from weather to anchor damage. Twenty-three per cent of the damage was considered moderate, eight per cent high to severe, and approximately six per cent was considered extremely severe. The majority of the moderate to extreme instances of damage occurred in the Cairns-Cooktown region and is attributed to damaging waves from storms, primarily associated with severe tropical cyclone Ita.
Further reef health surveys will be undertaken in the coming months to supplement the information gathered during the preliminary tropical cyclone Ita response surveys in April and early May 2014. The impacts of tropical cyclone Ita on other aspects of the Great Barrier Reef ecosystem such as water quality and seagrass meadows are still being investigated.
Want to help us keep an eye on the Great Barrier Reef? Find out more about our programs and how you can get involved.
A Vulnerability Assessment: of the issues that could have far-reaching consequences for the Great Barrier Reef.
Current Conditions: Environmental and climatic forecasts for the Great Barrier Reef