Blog Climate Change

Why we should be worried about this latest bleaching event on our Great Barrier Reef

by Yolanda Waters May 18, 2022

Yolanda WatersBy Yolanda Waters, environmental social scientist and community coordinator for Divers for Climate

An article published by the Cairns Post last week downplayed the severity of the recent mass bleaching event on the Great Barrier Reef and went so far as to question the latest reef health report. At a time when every fraction of a degree (and every vote)  matters, it is important to make sure that readers are clear on what is happening to our national icon.

I have been lucky enough to spend a lot of time on the Great Barrier Reef and on recent trips to the reef, particularly to popular tourism sites off Cairns, I have witnessed very minimal to mild bleaching. In fact, some reefs are in stunning condition.

But while I’ve been enjoying vibrant coral gardens, my friends and colleagues in Townsville have witnessed severe bleaching off John Brewer Reef (off Magnetic Island), previously listed as one of the healthiest reefs along the Great Barrier Reef, and are anxiously waiting for the water temperature to drop. We are yet to know the mortality rates of the latest bleaching event.

Marine heatwave

What is most concerning is that this bleaching event happened during a La Niña weather event which typically brings increased rain, cloud cover and cooler temperatures.  Though much of the East coast experienced its wettest summer yet, water temperatures from Cape York to Sydney remained unusually high.

Earlier this year, water temperatures on the Great Barrier Reef reached record highs and remained this way for over a month (For context, the optimal temperature range for most corals is between 23-29 degrees. Any higher than this, especially over long periods of time, can cause corals to bleach). So, while not every reef along the Great Barrier Reef experienced bleaching this year, the key point is that this marine heatwave should not have happened.

If the reef is experiencing widespread bleaching in a supposedly cooler year – what happens next year or the year after that? How many times can we cross our fingers hoping that the water cools down enough so that the coral can recover?

Yolanda WatersWhen talking about mass bleaching events, it is also important to emphasize the size and complexity of the Great Barrier Reef. Spanning over 2,300 kilometers and consisting of almost 2,000 individual, yet ecologically connected,  coral reefs – it is a scale that is extremely difficult to comprehend. What happens on one reef may not happen on another. And so while 91% of reefs may have experienced some level of bleaching this year (as reported by Great Barrier Reef Marine Park Authority), this does not mean that 91% of the coral you will see on the reef is dead or dying – it means that the reef needs help.


From a tourism perspective, I understand there are concerns about emphasizing bleaching severity and the damage done to the reef. But from my experience working with tourism operators and talking to visitors on the reef, people are confused and want to learn more – and they expect to hear it from us. Not only do they want to know what is going on but also how they can help. For example, people are often surprised to hear that the reef is made up of hundreds of individual reefs and that if given the time, bleached corals can recover. From what I have seen and heard so far I believe that this gives people hope that we can still work together and protect the reef.

So, while we still don’t know the long-term effects of this year’s bleaching event, what we know for sure is this – this is not a random or normal event, and these events will continue to become more frequent and severe if we do not limit global warming to 1.5 degrees. Why wait until it gets worse? We have all the tools that we need to take action now, we just need the political leadership to do it.

A shorter version of this blog was sent to the Cairns Post.