Your quick guide to the
Reef Summer Snapshot
Coral bleaching was mild last summer, but significant threats remain for the Great Barrier Reef.
The annual Reef Snapshot, published each autumn, provides a summary of conditions on the Great Barrier Reef during the previous summer. It explores how conditions impacted corals, other marine animals and their habitats.
The Great Barrier Reef Marine Park Authority, the Australian institute of Marine Science and CSIRO have today released the Snapshot for Summer 2022-23.
Here are the five things you need to know:
#1. The Reef had only minor coral bleaching
Compared to previous summers, the Reef showed lower levels of bleaching which allowed for some continued coral recovery and small increases in hard coral cover in certain areas. This is despite spring 2022 being the hottest on record, with the warmer water temperatures continuing into early summer. The unusual La Nina weather, which typically brings increased rainfall and lower temperatures, may have been a contributing factor in reducing the severity of bleaching.
#2. There were no cyclones over the Reef
Despite the La Nina weather cycle, no cyclones crossed the Reef during the summer months. Previous years have seen three to four cyclones per summer, which can cause significant wave damage, turning large areas of the Reef into rubble and making it harder for new baby corals to attach and grow.
#3. The key threats to the Reef remain
There were significant crown-of-thorns starfish (COTS) outbreaks from the North to the South of the Reef. Despite being a native coral predator, when COTS populations reach outbreak levels, they can decimate entire reefs and remain a significant threat to the Reef as a whole. Similarly, climate change remains the major threat to the Reef, despite lower-than-average water temperatures. Regardless of the summer’s reprieve, cumulative temperature increases continue, leaving less time for natural coral recovery.
Coral IVF is one of the solutions being investigated to help our Reef resist, adapt and recover from the impacts of climate change. Credit: SCU
#4. Solutions are underway
It’s critical that we support and build a more resilient Reef that can recover from the impacts of climate change each summer, and into the future. As part of the Reef Restoration and Adaptation Program we’re investigating ways we can intervene on the Reef to restore reefs and help corals adapt to a warmer future. This includes solutions like Coral IVF, which focuses on speeding up the return of coral cover and diversity through active collection and ‘seeding’ of coral babies back onto the Reef. However, these interventions are no substitute for action on climate change, with emissions reduction urgently needed alongside interventions.
#5. Next summer likely to be hotter than usual
The Australian Bureau of Meteorology is predicting this coming summer is twice as likely to experience El Nino conditions than average. This typically brings increased chance of drought, heatwaves, bushfires and – on the Reef – a higher chance of widespread coral bleaching.