Great Barrier Reef health update
by GBRMPA 13 Jun 2019 21:59 BST
Reef health updates © GBRMPA
From May to November 2019 we're releasing monthly updates on Reef health, key activities and biological processes occurring on the Reef.
More regular updates will be made over summer as it's the highest risk period for coral reefs due to elevated temperature, with corals highly sensitive to even small variations in temperature.
Unseasonal cyclone activity
An out-of-season tropical cyclone, tropical cyclone Ann, approached the far northern area of the Marine Park as a category two system on 12 May, but rapidly weakened to a tropical low before entering the Marine Park and crossing the far north Queensland coast near Lockhart River on 15 May. The system produced moderate rain falls in far north-eastern Queensland.
Dry season conditions returning
The dry season is returning and rainfall levels are forecast to be below average from June to August. Conditions are also likely to be warmer than usual across the north until temperatures across the south of the continent drop significantly.
El Niño and Indian Ocean Dipole
The ENSO Outlook was downgraded in May, with models now predicting a 50 per cent chance of an El Niño developing (down from a 70 per cent chance last month) by mid-2019. While sea surface temperatures are predicted to remain close to El Niño thresholds until mid-winter, water beneath the surface has cooled. A neutral ENSO state is most likely by October 2019.
Reef monitoring in the Whitsundays
The Australian Institute of Marine Science completed long-term monitoring surveys of the Whitsundays area of the Great Barrier Reef in May 2019. These are the first surveys of the area since cyclone Debbie in 2017. Surveys indicate coral cover on two of the reefs surveyed declined slightly since the last survey, which is most likely due to tropical cyclone Debbie. While overall average coral cover in this area remains at moderate levels, a number of high value tourism sites have been significantly impacted and are in the recovery phase.
Whale season under way
May marks the start of the humpback whale season on the Great Barrier Reef. From May to September each year, humpback whales come from Antarctic waters to the Great Barrier Reef World Heritage Area to calve over the winter before they return to the Antarctic in summer. Sightings of whales or other wildlife can be captured and shared using our Eye on the Reef app.