On Tuesday, the Great Barrier Reef Marine Park Authority (GBRMPA) ‘quietly’ published a report prepared alongside the Australian Institute of Marine Science (AIMS) and the Commonwealth Scientific Institute, Australia’s national science agency (CSIRO) which found that coral bleaching has affected 91% of the reefs they surveyed along the Great Barrier Reef this year.
The ‘Reef Snapshot 2021-2022’ survey conducted from December to March reveals that above average water temperatures in late summer had caused coral bleaching throughout the 2,300 km reef system, but particularly affected reefs between Cape Tribulation and the Whitsundays. The survey also found that bleaching began earlier than usual and lasted longer.
https://twitter.com/adamlmorton/status/1524137506312138754?s=20&t=wyp-IA-n3gwYqa2gqRa2OA
This report confirms that the natural landmark has suffered its sixth mass bleaching event on record in just over two decades.
Mass bleaching events are triggered by sea temperatures exceeding normal summer maximum temperatures for prolonged periods. The first global mass bleaching event took place in 1998, and then in 2002, 2016, 2017, 2020, and 2022. 2016 was the worst year on record, where 97% of surveyed reefs were affected.
Coral bleaching can be directly linked with global warming , and so climate change could cause the complete extinction of coral reefs if not taken seriously.
What is Coral Bleaching and why does it happen?
In healthy coral, tiny plants called zooxanthellae feed animal polyps through photosynthesis. Interactions between the two generate corals’ colours. In above-average water temperatures, coral polyps can become stressed and expel the photosynthetic algae that lives inside it.
If high temperatures persist, polyps permanently reject their plant partners, and the coral appears ‘bleached’. If the heat persists for too long, then coral will die. When coral dies, algae grows on it which restricts new colonies forming.
In the Reef Snapshot: 2021-2022 study, scientists from the AIMS surveyed 719 shallow water reefs between the Torres strait and the Capricorn Bunker group from low-level aerial surveys and satellite imaging at the southern end of the reef system. They found that 654 reefs showed bleaching from stress from December to March.
Although the bleached coral is not in fact ‘dead’, it is then much more vulnerable to dying. The study expects less ‘mortality’ this year than in 2016, but found more ‘extensive’ bleaching.
AIMS researcher Dr Neal Cantin said of the study:
“The surveys confirm a mass bleaching event, with coral bleaching observed at multiple reefs in all regions…This is the data everybody’s been waiting to see…It’s not a good sign and it’s happening more frequently, the first time during a La Niña event, so it is a clear sign of climate change escalating at the rate the reef isn’t keeping up with… I would expect the next El Niño to present a riskier summer, something as bad or worse than 2016”
Importantly, this was the first mass bleaching event to have been recorded during a cooler La Niña year. La Niña is the weather event characterised by stronger trade winds that push the jet stream northwards and causes more cloud cover and rainfall in the southern Hemisphere, whereas El Niño periods usually cause the hotter, drier spells associated with high water temperature periods and coral bleaching.
Scientist Dr David Wachenfeld told the Guardian:
“Coral bleaching is not expected in a La Niña year, but the climate is changing, and the planet and the reef is about 1.5 degrees warmer than it was 150 years ago…Unexpected events are now to be expected. Nothing surprises me anymore.”
Also poignant, is that the map shows that the most severe counts of bleaching occurred in the region covering the areas most visited by tourists. This is because coral can also be affected by overfishing, destructive fishing practices, unsustainable coastal development, and declining water quality.
While it is important to add that corals can survive bleaching events, the frequency of these events is not normal, and they do have long term impacts. Heat stress can make corals more susceptible to disease, slow their growth and limit their ability to spawn. With the knowledge of these recent events, coral bleaching in the Great Barrier Reef must now be considered in its political and environmental context.
“The science is very clear: in order to save the world’s reefs from total destruction, we must dramatically reduce emissions in the 2020s” said Dr Simon Bradshaw, Director of Research at the Climate Council.
Aftermath of the ‘Reef Snapshot 2022’: IPCC predictions, UNESCO intervention, and the upcoming Australian elections
Lissa Schindler, campaign manager for the Australian Marine Conservation Society, said the ‘devastating’ report was more evidence that cutting fossil fuel emissions should be top priority for the next Australian government.
The 2018 IPCC report found that limiting global warming to 1.5C rather than 2C would be the difference between some coral reefs surviving, and the total decline of coral reefs.
This is important for the Australian federal elections next week. Although the Labour party made a manifesto commitment to cut emissions by 2030 more than the Coalition whose commitments would mean a rise in temperature of over 3C, neither party’s targets are in line with what would be needed globally to save the reef.
Last year, UNESCO scientific advisors recommended that the Great barrier reef should be placed on a list of world heritage sites as ‘in danger’ due to the impact of the climate crisis and the slow progress of improving water quality.
Shocking to many, the Morrison government lobbied intensively to not put the site on the list and not follow the advice. The UN panel then agreed to defer the vote until 2022 and the government dodged the ‘in danger’ listing.
In March, UNESCO then undertook a 10-day trip to monitor the Great Barrier reef’s health and management, which coincided with the confirmation of severe coral bleaching having taken place. The Snapshot study will therefore help inform UNESCO’s decisions at the next world heritage meeting in June.
UNESCO’s involvement poses the question of why the publishing of the report, which was initially expected in April, has been delayed, even after scientists flagged the urgency of its publishing to the AIMS. The State of the Environment Report has also been stalled in the hands of the Environment Minister, Susan Ley since December.
As a result, the federal government and the AIMS have been accused of covering up findings during the run-up to the elections to shield itself from criticism.
The two have denied any political interference in the delayed release of the highly anticipated report ahead of the federal election.
Paul Hardisty CEO of AIMS told SBS news that releasing the survey results during the federal election campaign would have breached caretaker conventions. “There is no hiding it, there’s been no political coercion, there’s nothing like that going on” he said, “we’re being diligent, following due process”.
Dr Cantin, researcher in the study said in a webinar this week:
“Unfortunately we did not get (the report) out in time for the election and have been guided by the prime minister’s office (PMO), under caretaker mode, that we need to withhold the data until after the election for public release”.
Environment Minister Susan Ley also denied allegations in response to questions from SBS News:
“Three respective agencies are working to release the Reef Snapshot. Timing is at the discretion of those agencies”.
This is not the first time that Australia’s government has come under fire for their failures to save the Great Barrier Reef. While they have spent large sums on improving water quality, reef monitoring and habitat protection, A$1 billion ($738 million) this year, targets to curb carbon emissions have been far from ambitious.
It is carbon emissions that are most responsible for warming oceans and so it is them that need the government’s attention.
Losing coral reefs is an extremely dire prospect for Australia. Coral reefs are the most bio-diverse and productive ecosystems on the planet, they are hugely necessary for the survival of marine species, and people, and their extinction would have unquantifiably large impacts.
As coral reefs are one of the most sensitive indicators of ocean health, increasingly frequent damage to reefs means that much is wrong with how we are treating the ocean.
The latest annual IPCC report finds that there’s a 50% chance of global temperatures exceeding 1.5 degrees in the next five years, and so Australia must partake in efforts to dramatically reduce carbon emissions to try and prevent the demise of coral reefs.
Although allegations of ‘convenient’ timings in delaying the reports publishing have been denied, the timings can seem almost blatant. With nine days to go until the Australian federal election, it is imperative that political manoeuvring should not delay urgent climate action.
Editor’s Note: The opinions expressed here by Impakter.com columnists are their own, not those of Impakter.com. — In the Featured Photo: Bleached Acropora Coral Featured Photo Credit: Wikimedia Commons.
