UOW student Pipi Quinlan spearfishing in Cavalli Islands (NZ) | Image supplied.

During the summer of 2023/24, a mass coral bleaching event hit Australia’s iconic Great Barrier Reef (GBR), according to the Australian Institute of Marine Science (AIMS).

The GBR bleaching is part of the fourth global coral bleaching event which has bleached reefs in at least 57 countries and territories.

The event was sparked by 2023’s record-high global ocean heat, with an estimated 60 per cent of global coral reef experiencing bleaching-level heat stress, which is the highest on record, the US National Oceanic and Atmospheric Administration (NOAA) stated.

It is the fifth mass bleaching event on the GBR in just eight years.

UOW student and Dive Near Me Wollongong employee Pipi Quinlan, who works in marine tourism said she noticed a big change to the reef during a diving holiday in 2020.

“When I dove around the Whitsundays, it was honestly not the healthiest reef I’ve ever seen it,” she said.

“You could tell that the coral was stressed, and it wasn’t anywhere near as fishy as places that I have dove [elsewhere].

“This was sad to me – but it was after a big coral bleaching event, which I guess explained it.”


AIMS program director Dr David Wachenfeld said the 2023 event was unprecedented in its severity and impact on the reef.

“Certainly, in comparison to previous bleaching events, (the summer of 2024) is one of, or the absolute worst bleaching events the GBR has ever seen,” he said.

“In fact, 46 per cent of the 3,800 coral reefs on the GBR this year saw the greatest levels of heat stress that they have ever experienced, and in the worst affected areas we have already seen 75 percent coral mortality.

“But impacts are also variable across the length and breadth of the reef system and there are other reefs with no mortality whatsoever.

“Both heat stress and coral bleaching are the highest in the Southern GBR this year.”

Adding to the challenge, this summer, the GBR also faces additional stress from cyclones Jasper and Kirrily, which brought excess freshwater, sediments, and nutrients due to flooding.

Ms Quinlan said she was gutted by the bleaching event and the current condition of the reef, and believes this may have far-reaching consequences for the marine tourism industry of the area.

“You can’t put into words how much [the marine environment] means to me and my family,” she said.

“It’s a source of food at home, it’s a spiritual connection to it, and I also work within that sector.

“It’s a really emotional thing to see that ecosystems which you have appreciated and that have been celebrated by your family for so many years.

“(We) are less likely to go dive [the reef] because it’s just not appealing, and I’m sure a lot of divers would feel the same way, if [the bleaching and degradation] continues.”

Great Barrier Reef Tourism

Despite the mass coral bleaching event potentially discouraging some visitors, it hasn’t caused the tourism industry to suffer any great drops in tourism visitation.

This tourism trend is similar to the mass bleaching events in 2016 and 2017, which had the highest visitor figures on record.

In 2023, the reef saw 12.9 per cent fewer tourists compared to the pre-pandemic average, however tourism numbers have made a come-back over the past two years since travel restrictions were lifted.

According to the Great Barrier Reef Marine Park Authority (GBRMPA), the dip in tourist numbers is due to the lingering effects of the pandemic, not a lack of willingness to visit the reef due to any perceived decline in the its quality and appeal.

Marine biologist Phil Coulthard, manager of Quicksilver Group’s Reef Biosearch said he has not noticed any great shifts in the number of tourists attracted to their services.

Reef Biosearch manager Phil Coulthard conducting a GBR environmental tourist briefing | Image courtesy Quicksilver

“I don’t know the percentage of visitors that don’t [plan on coming] because they believe [the coral] is dead,” he said.

“But we don’t get a lot of people saying they’re not coming because of [the coral bleaching].

“In my experience, it’s a very low percentage of visitors asking questions [about the state of the reef] before their trip.”

Mr Coulthard said the company does take guests to reef areas where coral bleaching is visible, as guests are often more curious than deterred by it, and these experiences may actually be transformational.



Snorkel guide showing corals during an educational GBR tour | Image: Quicksilver

“When you have bleached coral it’s an initiator of a lot of discussion [with guests], based on not only what a coral is, but also why it’s lost its colour, the health of the reef and stressors from nearby land-based and ocean-based influences, and global climate change,” he said.

“This process of tourists seeing bleached coral on the reef is very, very powerful in changing attitudes and potentially giving them a chance to contribute to the solution.

“So, the bleaching really doesn’t affect where we go, but it really does have an influence on how we deliver messages to our guests.

“I think [by educating guests] we have great opportunity here to do good, especially when you consider the GBR has millions of tourists visiting every year.”

Reef Restoration

Reef Restoration Foundation CEO Ryan Donnelly said that both tourism and volunteers have played a vital role in supporting the restoration of the reef.

Coral reef bleaching and mortality at Fitzroy Island, after impacts of heat stress and cyclone Jasper  | Image: Cameron Bee, Reef Restoration Foundation

“Tourism is a great asset for the reef because they undertake a lot of monitoring and surveying. The Reef Authority even calls them the ‘eyes on the reef’,” Mr Donnelly said.

“Moreover, [our organisation] gets good work done with many reef restoration volunteers. Some partly assist just to be able to dive the reefs (for free), but they’re also very community-minded people, eager to contribute.

“We’re oversubscribed and closed registrations months ago, but we still receive daily volunteer requests from all around the world.

“This huge demand shows that the reef hasn’t lost its appeal, and a global community is seeking to optimistically [help the reef] during challenging times.”

Coral (Acropora sp.) growing in nursery for restoration | Image: Cameron Bee, Reef Restoration Foundation

Mr Donnelly said GBR tourist experiences are usually still very positive, with visitors starting from a different baseline of expectations.

“People sometimes get in the water thinking that it’s ‘last chance tourism’, because of how [the GBR] portrayed in the media. But the reality is more nuanced. When they get out, they often say it’s one of the best things they have ever done in their life.

“Maybe the day will come when it’s genuinely last chance tourism at the GBR, but right now we’re far from it.”

Biased Reporting & Recovery

Reminding us that warming oceans and coral bleaching are global issues, Mr Coulthard has warned against negative and alarmist media reporting, which he believes stems from the reef being the world’s most famous and well-documented reef system.

“If you get a little bit of bleaching on the reef, the entire 2700km length of the reef is [reported as] dead – very different than for reefs elsewhere, that often go unnoticed,” he said.

“Considering all stressors, the reef actually is considerably healthy – a lot better than what most people imagine it to be.

“Remember that the reef also recovers.  I surveyed a location just yesterday, and the corals that were bleached six weeks ago have fully recovered.

“Bleaching events are a concern, but I think if any reef has a chance of surviving because it’s so vast, biodiverse, and resilient.”

Ms Quinlan believes that more should be done to improve the reef’s situation.

“I’m sure lots of my peers have dove or snorkelled the reef in their lifetime, either with family or university friends – I know lots of my friends have,” she said.

“That’s not going to be an option if this continues, … it’s going to be all covered in algae with no fish.

“I think Australia could do better to be honest. As such an educated country with so many resources, there’s so much opportunity to protect it.”