What’s happening with the Great Barrier Reef bleaching? An update from experts and how to help
Whitsunday Islands on the Great Barrier Reef. Image: Sandrine Balaye/iStock
News story
26 March 2024
The average ocean water temperature this year has been consistently one of the hottest on record in Australia and globally. The marine heat wave is currently causing extensive coral bleaching on the Great Barrier Reef.
The Great Barrier Reef Marine Park Authority (GBRMPA) has announced that recent aerial surveys spanning two-thirds of the Great Barrier Reef Marine Park have confirmed widespread coral bleaching.
Additional in-water research is also underway at various points along the coast and will provide more detail on bleaching depths and coral responses at those locations.
We asked 4 experts about what's happening. Here are some key take-aways or read on below for their full analysis.
- This bleaching is far more extensive than previous events
- Reef restoration actions can't match the scale - to save the reef we need climate action
- This is a threat to First Peoples Culture and livelihoods
- We all have a role to play to save the reef by taking personal climate action
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This bleaching is far more extensive than previous events
Biodiversity Councillor Professor Catherine Lovelock from The University of Queensland is part of the GBRMPA Independent Expert Panel:
“Reefs along the entire length of the Great Barrier Reef appear to be affected. Official estimates have not yet been released but there is anecdotal evidence of severe bleaching from the Torres Straits as far south as Lord Howe Island.
“After previous bleaching events we did see recovery at some places like Lizard Island and these places have been heavily affected this year.
“Bleached coral does not always die, but the longer the water is a stressful temperature for the coral the more likely it is to die. Ocean temperatures are now possibly declining but are still above normal and therefore contributing to cumulative heat stress.
“The marine heatwave may also have had impacts on seagrasses and other components of the biodiversity of the Great Barrier Reef, which dugongs and other fauna depend on - but we do not yet have reports on these.
“This is the fifth bleaching event in only 8 years, but those other events tended to be clustered around particular sections of the reef; this event is different due to its massive extent. The number of days for which corals have been exposed to water temperatures above their thermal limit is also higher than most previous events.”
Reef restoration actions can't match the scale - to save the reef we need climate action
Biodiversity Councillor Professor Graeme Cumming from The University of Western Australia Oceans Institute was previously Director of the ARC Centre of Excellence for Coral Reef Studies at James Cook University.
“There has been reporting that the extent of coral cover was greater than ever before this bleaching event.
“This is true, but the new corals were primarily fast growing ‘weedy’ Acropora coral species, so the new areas of coral don’t have the diversity of coral types and species that we expect on the reef.
“The Acropora corals are also particularly vulnerable to bleaching, so will be heavily impacted by this marine heatwave.
“Large, old corals are being lost in these bleaching events and the younger corals do not have as high a reproductive output, so the number of new corals recruiting along the reef is likely to further decline.
“Survival of the Great Barrier Reef is in the lap of natural selection, which is currently acting on the billions of live corals that remain along the reef. There are some practical interventions that would help corals by reducing other stresses, this includes reducing nutrients and pollution from catchments, and over-fishing and shipping impacts.
“Coral reef restoration activities can’t match the pace or scale of the coral losses caused by climate change. The fundamental problem is that we need action to reduce carbon emissions to stop the earth from over-heating.”
This is a threat to Culture and livelihoods
Biodiversity Councillor Stan Lui is a Torres Strait Islander from Erub (Darnley Island) has worked in senior roles in fisheries management, aquaculture development and natural resources management for state and federal governments.
“The recent coral bleaching event on the Great Barrier Reef signifies a dire threat not only to its vast biodiversity but also profoundly impacts the cultural and economic foundations of Aboriginal and Torres Strait Islander peoples.
“These communities, whose identities are deeply woven into the fabric of their Sea Country, are witnessing the degradation of essential cultural practices, sacred sites, and centuries-old knowledge. The event further undermines important fisheries, pivotal to their ways of life and livelihoods, by diminishing fish populations and degrading marine habitats critical for cultural, commercial, and recreational purposes.
“This crisis underscores the urgent need for global cooperation to mitigate climate change and integrate Indigenous knowledge into conservation strategies, ensuring the reef's preservation as both a biodiversity haven and a cultural treasure.
“Moreover, the ecosystem services provided by the Great Barrier Reef are essential to the cultural, spiritual, and physical well-being of these Indigenous communities. Their traditional practices, livelihoods, and very survival are intricately linked to the health of the Reef, highlighting the necessity for concerted conservation efforts that respect and incorporate Indigenous wisdom and leadership.
“Protecting the Great Barrier Reef, therefore, transcends environmental conservation, becoming a matter of cultural preservation and recognition of Indigenous peoples' rights and contributions to the stewardship of their ancestral lands and waters.”
We all have a role to play to save the reef
Biodiversity Councillor Dr Angela Dean from The University of Queensland is a conservation social scientist working with a range of government and non-government partners on reef stewardship programs.
“The Great Barrier Reef is part of our Australian identity, whether we live in Cairns or Tasmania we all care about what happens to the reef and wherever we live, we can all make a difference.
“Climate change is the number one threat to the reef so we need to do everything we can to decarbonise.
“The first way we can help is by taking personal climate action, for example by switching off lights we aren’t using, installing solar, and switching some of our car trips to public transport or bicycle.
“The second way every Australian can help is through civic action. We can contact our political representatives and governments and let them know that we want more action to decarbonise Australia to protect the reef and our diplomats need to be pushing other countries to do the same.”
Research led by Dr Dean found that most Australians do not connect reef conservation with individual climate actions, even though reducing carbon emissions is the most important action to conserve the reef. University of Queensland Doctoral Researcher Yolanda Waters has prepared an evidence-based factsheet on the most effective communication messages to motivate climate-action to conserve the reef.