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By Amy Edwards 27 April 2021 6 min read

A snorkeler exploring the exceptional coral gardens at John Brewer Reef, September 2020. Image by Matt Curnock, CSIRO. ©  Matt Curnock +61 408 871 603

The Great Barrier Reef has been given a breather this summer. 

Summer is a critical time for the health of coral. The greatest threat to the Reef is climate change and summer is often a time when the major climate impacts express themselves.  

Think high sea temperatures, coral bleaching, flood plumes and cyclones. 

Climate change influences weather patterns and the ocean’s temperatureUnfortunately, the events that cause disturbances on the Reef are becoming more frequent and/or intense, leaving less time for coral recovery. 

But this summer, media reports have not been dominated with tales about marine heatwaves or reef grief.

And because the Reef has a wealth of marine biodiversity unmatched anywhere in the world, we suspect there were plenty of happy little Nemos enjoying the good conditions for their coral homes this summer. 

State of the Reef  

Conditions this summer were relatively uneventful, in a positive way,” says Great Barrier Reef Marine Park Authority CEO Josh Thomas.  

“This is good news for the Reef’s corals, as it will have given reefs damaged in previous years an opportunity to continue their recovery.  

However, Josh is mindful that a summer without a crisis event on the Reef, does not mean the Reef is out of the woods.  It has experienced a variety of disturbances over the past decade and global action on climate change remains critical. 

So what was the good news this summer? 

Water temperatures did not cause as much coral heat stress this summer as in recent years, although all months were warmer than average.  

Kimi was the only tropical cyclone to spend significant time on the Reef, reducing the risk of coral reefs being exposed to damaging waves. And, while there was some good rainfall in the catchments, flood levels in waterways near the Reef were generally not major or sustained.  

Crown-of-thorns starfish remain at outbreak, or potential outbreak, levels in parts of the northern, central and (particularly) southern regions of the Reef. The COTS Control Program continues to work in all three regions to cull starfish down to non-outbreak levels.  

Scientists were telling a more dramatic story during the previous summer.  

For example, in February 2020, the Great Barrier Reef experienced the warmest sea surface on record for any month since 1900. It was 1.25°C above average. Just one month later on 26 March 2020, the Great Barrier Reef Marine Park Authority confirmed that mass bleaching had occurred on the Great Barrier Reef due to the warmer than average water. 

A couple of snorkelers exploring the northern reef wall at John Brewer Reef, offshore from Townsville. Image by Matt Curnock, CSIRO ©  Matt Curnock +61 408 871 603

The Reef snapshot  

Each year the Australian Government’s leading management and science agencies for the Great Barrier Reefthe Great Barrier Reef Marine Park Authority (Reef Authority)the Australian Institute of Marine Science (AIMS) and CSIRO, produce a  Reef snapshot document. 

Released today, the summer 2020-21 Reef snapshot provides coral health summaries for different regions of the Reef over the past summerDue to its large size, disturbances can vary across different locations. It also highlights some of the inspiring science and management underway to better understand and protect coral. 

AIMS CEO Dr Paul Hardisty said the snapshot reflected a unified view from the three Australian Government agencies involved in preserving the economic, societal, and environmental value of the Reef.  

“Through this joint approach to the Reef we each contribute different capabilities and apply the best available knowledge to ensure a healthy ecosystem for future generations.  As the nation’s tropical marine science agency, AIMS brings a range of scientific expertise, including long-term understanding of how disturbances affect the cycles of coral decline and recovery,” Paul says. 

Focused on the future 

A local dive tourism operator from Townsville, visiting John Brewer Reef. Image by Matt Curnock, CSIRO. ©  Matt Curnock +61 408 871 603

And while we are certain our favourite natural Aussie icon deserved a good summer vacay this year, researchers aren’t resting on their laurels just yet. 

“A good summer releases the pressure valve a little so we can focus on our longer-term goals rather than managing an extreme event,” CSIRO Great Barrier Reef research coordinator Dr Bruce Taylor says. 

This has come at a good time for the Reef and its researchers. We are moving from a period of scoping and planning into active management and resilience building on the Reef. 

Bruce says an example of this is the Reef Restoration and Adaptation Program which has moved from a scoping phase into its research and development phase. 

In April 2020 the research and development phase of this Restoration Program (phase 2) was launched with an initial $150 million investment to test and apply novel interventions. These range from cultivating and repopulating coral larvae on the Reef, to measures to shade and cool large areas of the Reef at risk of bleaching. Using modelling, scientists have considered how effective the novel interventions would be in current conditions, as well as moderate and severe climate change scenarios.  

CSIRO is co-leading the moving corals, ecological intelligence, and stakeholder and Traditional Owner engagement components of the Restoration Program.  CSIRO is also a major contributor to modelling and decision-support components to progress delivery with the other partners. The program's R&D phase is funded by the partnership between the Australian Government’s Reef Trust and the Great Barrier Reef Foundation. 

In addition to this program moving into a new phase, the updated Reef 2050 Long-Term Sustainability Plan by the Federal Government’s Department of Water and Environment, the Reef Authority and the Queensland Government Office of the Great Barrier Reef is likely to be released in the coming weeks. 

While the Reef faces unprecedented pressures, its astounding beauty continues to inspire people. 

Opportunities to visit in a COVID safe way are now increasing and people from Australia and around the world are encouraged to see its beauty and to take actions to protect it for future generations. 

“It’s essential our marine tourism industry is healthy and happy. They provide important eyes and ears of what is happening on the Reef,” Bruce says. 

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