If we can put a man on the Moon, we can save the Great Barrier Reef



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Paul Hardisty, Australian Institute of Marine Science; Christian Roth, CSIRO; Damien Burrows, James Cook University; David Mead, Australian Institute of Marine Science; Ken Anthony, Australian Institute of Marine Science; Line K Bay, Australian Institute of Marine Science; Mark Gibbs, Queensland University of Technology, and Peter J Mumby, The University of Queensland

Scientists recently confirmed the Great Barrier Reef suffered another serious bleaching event last summer – the third in five years. Dramatic intervention to save the natural wonder is clearly needed.

First and foremost, this requires global greenhouse gas emissions to be slashed. But the right combination of technological and biological interventions, deployed with care at the right time and scale, are also critical to securing the reef’s future.




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We just spent two weeks surveying the Great Barrier Reef. What we saw was an utter tragedy


This could include methods designed to shade and cool the reef, techniques to help corals adapt to warmer temperatures, ways to help damaged reefs recover, and smart systems that target interventions to the most strategically beneficial locations.

Research into breeding coral hybrids for heat-stress resistance could help restore parts of the reef.
Marie Roman/AIMS, Author provided

Implementing such measures across the breadth of the reef – the world’s biggest reef ecosystem – will not be easy, or cheap. In fact, we believe the scale of the task is greater than the Apollo 11 Moon landing mission in 1969 – but not impossible.

That mission was a success, not because a few elements worked to plan, but because of the integration, coordination and alignment of every element of the mission’s goal: be the first to land and walk on the Moon, and then fly home safely.

Half a century later, facing the ongoing decline of the Great Barrier Reef, we can draw important lessons from that historic human achievement.

Intervening to save the reef

The recently released Reef Restoration and Adaptation Program concept feasibility study shows Australia could feasibly, and with reasonable probability of success, intervene to help the reef adapt to and recover from the effects of climate change.

The study, of which we were a part, involved more than 100 leading coral reef scientists, modellers, economists, engineers, business strategists, social scientists, decision scientists and reef managers.

More than 100 coral reef scientists took part in the feasibility study.
Nick Thake/AIMS, Author provided

It shows how new and existing interventions, supported by the best available research and development, could help secure a future for the reef.

We must emphasise that interventions to help the reef adapt to and recover from climate change will not, alone, save it. Success also depends on reducing global greenhouse emissions as quickly as possible. But the hands-on measures we’re proposing could help buy time for the reef.

Cloud brightening to heat-tolerant corals

Our study identified 160 possible interventions that could help revive the reef, and build on its natural resilience. We’ve whittled it down to the 43 most effective and realistic.

Possible interventions for further research and development include brightening clouds with salt crystals to shade and cool corals; ways to increase the abundance of naturally heat-tolerant corals in local populations, such as through aquarium-based selective breeding and release; and methods to promote faster recovery on damaged reefs, such as deploying structures designed to stabilise reef rubble.

But there will be no single silver bullet solution. The feasibility study showed that methods working in combination, along with water quality improvement and crown-of-thorns starfish control, will provide the best results.

Field testing the heat resistant coral hybrids in the Great Barrier Reef.
Kate Green/AIMS, Author provided

Harder than landing on the Moon

There are four reasons why saving the Great Barrier Reef in coming decades could be more challenging than the 1969 Moon mission.

First, warming events have already driven the reef into decline with back-to-back bleaching events in 2016 and 2017, and now again in 2020. The next major event is now only just around the corner.




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Second, current emission reduction pledges would see the world warm by 2.3-3.5℃ relative to pre-industrial levels. This climate scenario, which is not the worst case, would be beyond the range that allows today’s coral reef ecosystems to function.

Without swift action, the prospect for the world’s coral reefs is bleak, with most expected to become seriously degraded before mid-century.

The Great Barrier Reef has been hit by consecutive bleaching events – restoring it may be harder than landing on the moon.
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Third, we still have work to do to control local pressures, including water quality and marine pests crown-of-thorns starfish.

And fourth, the inherent complexity of natural systems, particularly ones as diverse as coral reefs, provides an additional challenge not faced by NASA engineers 50 years ago.

So keeping the Great Barrier Reef, let alone the rest of the world’s reefs, safe from climate change will dwarf the challenge of any space mission. But there is hope.

We must start now

The federal government recently re-announced A$100 million from the Reef Trust Partnership towards a major research and development effort for this program. This will be augmented by contributions of A$50m from research institutions, and additional funding from international philanthropists.

Our study shows that under a wide range of future emission scenarios, the program is very likely to be worth the effort, more so if the world meets the Paris target and rapidly cuts greenhouse gas emissions.




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I studied what happens to reef fish after coral bleaching. What I saw still makes me nauseous


What’s more, economic analyses included in the feasibility study show successful Great Barrier Reef intervention at scale could create benefits to Australia of between A$11 billion and A$773 billion over a 60-year period, with much of it flowing to regional economies and Traditional Owner communities.

And perhaps more importantly, if Australia is successful in this effort, we can lead the world in a global effort to save these natural wonders bequeathed to us across the ages. We must start the journey now. If we wait, it may be too late.


The authors gratefully acknowledge the contribution of David Wachenfeld, Chief Scientist of the Great Barrier Reef Marine Park Authority and member of the the steering committee for the development of this program.The Conversation

Paul Hardisty, CEO, Australian Institute of Marine Science; Christian Roth, CSIRO Great Barrier Reef Coordinator & Senior Principal Research Scientist, CSIRO; Damien Burrows, Director of TropWATER, James Cook University; David Mead, Executive Director of Strategic Development at Australian Institute of Marine Science, Australian Institute of Marine Science; Ken Anthony, Principal Research Scientist, Australian Institute of Marine Science; Line K Bay, Senior Research Scientist and Team Leader, Australian Institute of Marine Science; Mark Gibbs, Director, Knowledge to Innovation; Chair, Green Cross Australia, Queensland University of Technology, and Peter J Mumby, Chair professor, The University of Queensland

This article is republished from The Conversation under a Creative Commons license. Read the original article.

5 big environment stories you probably missed while you’ve been watching coronavirus



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Rod Lamberts, Australian National University and Will J Grant, Australian National University

Good news: COVID-19 is not the only thing going on right now!

Bad news: while we’ve all been deep in the corona-hole, the climate crisis has been ticking along in the background, and there are many things you may have missed.

Fair enough – it’s what people do. When we are faced with immediate, unambiguous threats, we all focus on what’s confronting us right now. The loss of winter snow in five or ten years looks trivial against images of hospitals pushed to breaking point now.




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While we fixate on coronavirus, Earth is hurtling towards a catastrophe worse than the dinosaur extinction


As humans, we also tend to prefer smaller, short-term rewards over larger long-term ones. It’s why some people would risk illness and possible prosecution (or worse, public shaming) to go to the beach with their friends even weeks after social distancing messages have become ubiquitous.

But while we might need to ignore climate change right now if only to save our sanity, it certainly hasn’t been ignoring us.

So here’s what you may have missed while coronavirus dominates the news cycle.

Heatwave in Antarctica

Antarctica is experiencing alarmingly balmy weather.
Shutterstock

On February 6 this year, the northernmost part of Antarctica set a new maximum temperature record of 18.4℃. That’s a pleasant temperature for an early autumn day in Canberra, but a record for Antarctica, beating the old record by nearly 1℃.

That’s alarming, but not as alarming as the 20.75℃ reported just three days later to the east of the Antarctic Peninsula at Marambio station on Seymour Island.




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Anatomy of a heatwave: how Antarctica recorded a 20.75°C day last month


Bleaching the reef

The Intergovernmental Panel on Climate Change has warned a global average temperature rise of 1.5℃ could wipe out 90% of the world’s coral.

As the world looks less likely to keep temperature rises to 1.5℃, in 2019 the five-year outlook for Australia’s Great Barrier Reef was downgraded from “poor” to “very poor”. The downgrading came in the wake of two mass bleaching events, one in 2016 and another in 2017, damaging two-thirds of the reef.

And now, in 2020, it has just experienced its third in five years.

Of course, extreme Antarctic temperatures and reef bleaching are the products of human-induced climate change writ large.

But in the short time since the COVID-19 crisis began, several examples of environmental vandalism have been deliberately and specifically set in motion as well.




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We just spent two weeks surveying the Great Barrier Reef. What we saw was an utter tragedy


Coal mining under a Sydney water reservoir

The Berejiklian government in New South Wales has just approved the extension of coal mining by Peabody Energy – a significant funder of climate change denial – under one of Greater Sydney’s reservoirs. This is the first time such an approval has been granted in two decades.

While environmental groups have pointed to significant local environmental impacts – arguing mining like this can cause subsidence in the reservoir up to 25 years after the mining is finished – the mine also means more fossil carbon will be spewed into our atmosphere.

Peabody Energy argues this coal will be used in steel-making rather than energy production. But it’s still more coal that should be left in the ground. And despite what many argue, you don’t need to use coal to make steel.




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Albanese says we can’t replace steelmaking coal. But we already have green alternatives


Victoria green-lights onshore gas exploration

In Victoria, the Andrews government has announced it will introduce new laws into Parliament for what it calls the “orderly restart” of onshore gas exploration. In this legislation, conventional gas exploration will be permitted, but an existing temporary ban on fracking and coal seam gas drilling will be made permanent.

The announcement followed a three-year investigation led by Victoria’s lead scientist, Amanda Caples. It found gas reserves in Victoria “could be extracted without harming the environment”.

Sure, you could probably do that (though the word “could” is working pretty hard there, what with local environmental impacts and the problem of fugitive emissions). But extraction is only a fraction of the problem of natural gas. It’s the subsequent burning that matters.




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Victoria quietly lifted its gas exploration pause but banned fracking for good. It’s bad news for the climate


Trump rolls back environmental rules

Meanwhile, in the United States, the Trump administration is taking the axe to some key pieces of environmental legislation.

One is an Obama-era car pollution standard, which required an average 5% reduction in greenhouse emissions annually from cars and light truck fleets. Instead, the Trump administration’s “Safer Affordable Fuel Efficient Vehicles” requires just 1.5%.

The health impact of this will be stark. According to the Environmental Defense Fund, the shift will mean 18,500 premature deaths, 250,000 more asthma attacks, 350,000 more other respiratory problems, and US$190 billion in additional health costs between now and 2050.

And then there are the climate costs: if manufacturers followed the Trump administration’s new looser guidelines it would add 1.5 billion tonnes of carbon dioxide to the atmosphere, the equivalent of 17 additional coal-fired power plants.




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And so…

The challenges COVID-19 presents right now are huge. But they will pass.

The challenges of climate change are not being met with anything like COVID-19 intensity. For now, that makes perfect sense. COVID-19 is unambiguously today. Against this imperative, climate change is still tomorrow.

But like hangovers after a large celebration, tomorrows come sooner than we expect, and they never forgive us for yesterday’s behaviour.The Conversation

Rod Lamberts, Deputy Director, Australian National Centre for Public Awareness of Science, Australian National University and Will J Grant, Senior Lecturer, Australian National Centre for the Public Awareness of Science, Australian National University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

We just spent two weeks surveying the Great Barrier Reef. What we saw was an utter tragedy



Author supplied

Terry Hughes, James Cook University and Morgan Pratchett, James Cook University

The Australian summer just gone will be remembered as the moment when human-caused climate change struck hard. First came drought, then deadly bushfires, and now a bout of coral bleaching on the Great Barrier Reef – the third in just five years. Tragically, the 2020 bleaching is severe and the most widespread we have ever recorded.

Coral bleaching at regional scales is caused by spikes in sea temperatures during unusually hot summers. The first recorded mass bleaching event along Great Barrier Reef occurred in 1998, then the hottest year on record.




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Since then we’ve seen four more mass bleaching events – and more temperature records broken – in 2002, 2016, 2017, and again in 2020.

This year, February had the highest monthly sea surface temperatures ever recorded on the Great Barrier Reef since the Bureau of Meteorology’s records began in 1900.

Not a pretty picture

We surveyed 1,036 reefs from the air during the last two weeks in March, to measure the extent and severity of coral bleaching throughout the Great Barrier Reef region. Two observers, from the ARC Centre of Excellence for Coral Reef Studies and the Great Barrier Reef Marine Park Authority, scored each reef visually, repeating the same procedures developed during early bleaching events.

The accuracy of the aerial scores is verified by underwater surveys on reefs that are lightly and heavily bleached. While underwater, we also measure how bleaching changes between shallow and deeper reefs.




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Of the reefs we surveyed from the air, 39.8% had little or no bleaching (the green reefs in the map). However, 25.1% of reefs were severely affected (red reefs) – that is, on each reef more than 60% of corals were bleached. A further 35% had more modest levels of bleaching.

Bleaching isn’t necessarily fatal for coral, and it affects some species more than others. A pale or lightly bleached coral typically regains its colour within a few weeks or months and survives.

The 2020 coral bleaching event was the second-worst in more than two decades.
ARC Centre of Excellence for Coral Reef Studies

But when bleaching is severe, many corals die. In 2016, half of the shallow water corals died on the northern region of the Great Barrier Reef between March and November. Later this year, we’ll go underwater to assess the losses of corals during this most recent event.

Compared to the four previous bleaching events, there are fewer unbleached or lightly bleached reefs in 2020 than in 1998, 2002 and 2017, but more than in 2016. Similarly, the proportion of severely bleached reefs in 2020 is exceeded only by 2016. By both of these metrics, 2020 is the second-worst mass bleaching event of the five experienced by the Great Barrier Reef since 1998.

The unbleached and lightly bleached (green) reefs in 2020 are predominantly offshore, mostly close to the edge of the continental shelf in the northern and southern Great Barrier Reef. However, offshore reefs in the central region were severely bleached again. Coastal reefs are also badly bleached at almost all locations, stretching from the Torres Strait in the north to the southern boundary of the Great Barrier Reef Marine Park.



CC BY-ND

For the first time, severe bleaching has struck all three regions of the Great Barrier Reef – the northern, central and now large parts of the southern sectors. The north was the worst affected region in 2016, followed by the centre in 2017.

In 2020, the cumulative footprint of bleaching has expanded further, to include the south. The distinctive footprint of each bleaching event closely matches the location of hotter and cooler conditions in different years.

Poor prognosis

Of the five mass bleaching events we’ve seen so far, only 1998 and 2016 occurred during an El Niño – a weather pattern that spurs warmer air temperatures in Australia.

But as summers grow hotter under climate change, we no longer need an El Niño to trigger mass bleaching at the scale of the Great Barrier Reef. We’ve already seen the first example of back-to-back bleaching, in the consecutive summers of 2016 and 2017. The gap between recurrent bleaching events is shrinking, hindering a full recovery.

For the first time, severe bleaching has struck all three regions of the Great Barrier Reef.
ARC Centre of Excellence for Coral Reef Studies

After five bleaching events, the number of reefs that have escaped severe bleaching continues to dwindle. Those reefs are located offshore, in the far north and in remote parts of the south.

The Great Barrier Reef will continue to lose corals from heat stress, until global emissions of greenhouse gasses are reduced to net zero, and sea temperatures stabilise. Without urgent action to achieve this outcome, it’s clear our coral reefs will not survive business-as-usual emissions.




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I studied what happens to reef fish after coral bleaching. What I saw still makes me nauseous


The Conversation


Terry Hughes, Distinguished Professor, James Cook University and Morgan Pratchett, Professor, ARC Centre of Excellence for Coral Reef Studies, James Cook University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

I studied what happens to reef fish after coral bleaching. What I saw still makes me nauseous



Victor Huertas, Author provided

Jodie L. Rummer, James Cook University

The Great Barrier Reef is suffering its third mass bleaching event in five years. It follows the record-breaking mass bleaching event in 2016 that killed a third of Great Barrier Reef corals, immediately followed by another in 2017.

While we don’t know if fish populations declined from the 2016 bleaching disaster, one 2018 study did show the types of fish species on some coral reefs changed. Our study dug deeper into fish DNA.

I was part of an international team of scientists that, for the first time, tracked wild populations of five species of coral reef fish before, during, and after the 2016 marine heatwave.

From a scientific perspective, the results are fascinating and world-first.

Marine heatwaves are now becoming more frequent and more severe with climate change. Corals are bleaching, as pictured here.
Jodie Rummer, Author provided

We used gene expression as a tool to survey how well fish can handle hotter waters. Gene expression is the process where a gene is read by cell machinery and creates a product such as a protein, resulting in a physical trait.

We know many tropical coral reef fish are already living at temperatures close to their upper limits. Our findings can help predict which of these species will be most at risk from repeated heatwaves.




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But from a personal perspective, I still feel nauseous thinking about what the reef looked like during this project. I’ll probably feel this way for a long time.

Rewind to November 2015

We were prepared. Back then we didn’t know the reef was about to bleach and lead to widespread ecological devastation. But we did anticipate that 2016 would be an El Niño year. This is a natural climate cycle that would mean warm summer waters in early 2016 would stick around longer than usual.

But we can’t blame El Niño – the ocean has already warmed by 1°C above pre-industrial levels from continued greenhouse gas emissions. What’s more, marine heatwaves are becoming more frequent and severe with climate change.

Given this foresight, we took some quick liver biopsies from several coral reef fish species at our field site in December 2015, just in case.

Coral bleaching at Magnetic Island, March 2020.
Victor Huertas, Author provided

A couple months later, we were literally in hot water

In February 2016, my colleague and I were based on Lizard Island in the northern part of the Great Barrier Reef working on another project.

The low tides had shifted to the afternoon hours. We were collecting fish in the shallow lagoon off the research station, and our dive computers read that the water temperature was 33°C.




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We looked at each other. These are the temperatures we use to simulate climate change in our laboratory studies for the year 2050 or 2100, but they’re happening now.

Over the following week, we watched corals turn fluorescent and then bone-white.

The water was murky with slime from the corals’ immune responses and because they were slowly exuding their symbiotic zooxanthellae – the algae that provides corals with food and the vibrant colours we know and love when we think about a coral reef. The reef was literally dying before our eyes.

A third of the corals on the Great Barrier Reef perished after the 2016 heatwave.
Jodie Rummer, Author provided

Traits for dealing with heatwaves

We sampled fish during four time periods around this devastating event: before, at the start, during, and after.

Some genes are always “switched on”, regardless of environmental conditions. Other genes switch on or off as needed, depending on the environment.

If we found these fish couldn’t regulate their gene expression in response to temperature stress, then the functions – such as metabolism, respiration, and immune function – also cannot change as needed. Over time, this could compromise survival.




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The plasticity (a bit like flexibility) of these functions, or phenotypes, is what buffers an organism from environmental change. And right now, this may be the only hope for maintaining the health of coral reef ecosystems in the face of repeated heatwave events.

So, what were the fish doing?

We looked at expression patterns of thousands of genes. We found the same genes responded differently between species. In other words, some fish struggled more than others to cope with marine heatwaves.

Ostorhinchus doederleini, a species of cardinalfish, is bad at coping with marine heatwaves.
Göran Nilsson, Author provided

The species that coped the least was a nocturnal cardinalfish species (Cheilodipterus quinquelineatus). We found it had the lowest number of differentially expressed genes (genes that can switch on or off to handle different stressors), even when facing the substantial change in conditions from the hottest to the coolest months.

In contrast, the spiny damselfish (Acanthochromis polyacanthus) responded to the warmer conditions with changes in the expression of thousands of genes, suggesting it was making the most changes to cope with the heatwave conditions.

What can these data tell us?

Our findings not only have implications for specific fish species, but for the whole ecosystem. So policymakers and the fishing industry should screen more species to predict which will be sensitive and which will tolerate warming waters and heatwaves. This is not a “one size fits all” situation.

One of the species that showed the least amount of change under warming was Cheilodipterus quinquelineatus.
Moises Antonio Bernal de Leon, Author provided

Fish have been on the planet for more than 400 million years. Over time , they may adapt to rising temperatures or migrate to cooler waters.

But, the three recent mass bleaching events is unprecedented in human history, and fish won’t have time to adapt.




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Attention United Nations: don’t be fooled by Australia’s latest report on the Great Barrier Reef


My drive to protect the oceans began when I was a child. Now it’s my career. Despite the progress my colleagues and I have made, my nauseous feelings remain, knowing our science alone may not be enough to save the reef.

The future of the planet, the oceans, and the Great Barrier Reef lies in our collective actions to reduce global warming. What we do today will determine what the Great Barrier Reef looks like tomorrow.The Conversation

Jodie L. Rummer, Associate Professor & Principal Research Fellow, James Cook University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Meet the super corals that can handle acid, heat and suffocation


Resilient corals are offering hope for bleached reefs.
Emma Camp

Emma F Camp, University of Technology Sydney and David Suggett, University of Technology Sydney

Climate change is rapidly changing the oceans, driving coral reefs around the world to breaking point. Widely publicised marine heatwaves aren’t the only threat corals are facing: the seas are increasingly acidic, have less oxygen in them, and are gradually warming as a whole.

Each of these problems reduces coral growth and fitness, making it harder for reefs to recover from sudden events such as massive heatwaves.




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Acid oceans are shrinking plankton, fuelling faster climate change


Our research, published today in Marine Ecology Progress Series, investigates corals on the Great Barrier Reef that are surprisingly good at surviving in increasingly hostile waters. Finding out how these “super corals” can live in extreme environments may help us unlock the secret of coral resilience helping to save our iconic reefs.

Bleached coral in the Seychelles.
Emma Camp, Author provided

Coral conservation under climate change

The central cause of these problems is climate change, so the central solution is reducing carbon emissions. Unfortunately, this is not happening rapidly enough to help coral reefs, so scientists also need to explore more immediate conservation options.

To that end, many researchers have been looking at coral that manages to grow in typically hostile conditions, such as around tide pools and intertidal reef zones, trying to unlock how they become so resilient.

These extreme coral habitats are not only natural laboratories, they house a stockpile of extremely tolerant “super corals”.

What exactly is a super coral?

“Super coral” generally refers to species that can survive both extreme conditions and rapid changes in their environment. But “super” is not a very precise term!

Our previous research quantified these traits so other ecologists can more easily use super coral in conservation. There are a few things that need to be established to determine whether a coral is “super”:

  1. What hazard can the coral survive? For example, can it deal with high temperature, or acidic water?

  2. How long did the hazard last? Was it a short heatwave, or a long-term stressor such as ocean warming?

  3. Did the coral survive because of a quality such as genetic adaption, or was it tucked away in a particularly safe spot?

  4. How much area does the coral cover? Is it a small pocket of resilience, or a whole reef?

  5. Is the coral trading off other important qualities to survive in hazardous conditions?

  6. Is the coral super enough to survive the changes coming down the line? Is it likely to cope with future climate change?

If a coral ticks multiple boxes in this list, it’s a very robust species. Not only will it cope well in our changing oceans, we can also potentially distribute these super corals along vulnerable reefs.

Some corals cope surprisingly well in different conditions.
Emma Camp, Author provided

Mangroves are surprise reservoirs

We discovered mangrove lagoons near coral reefs can often house corals living in very extreme conditions – specifically, warm, more acidic and low oxygen seawater.

Previously we have reported corals living in extreme mangroves of the Seychelles, Indonesia, New Caledonia – and in our current study living on the Great Barrier Reef. We report diverse coral populations surviving in conditions more hostile than is predicted over the next 100 years of climate change.

Importantly, while some of these sites only have isolated populations, other areas have actively building reef frameworks.

Particularly significant were the two mangrove lagoons on the Great Barrier Reef. They housed 34 coral species, living in more acidic water with very little oxygen. Temperatures varied widely, over 7℃ in the period we studied – and included periods of very high temperatures that are known to cause stress in other corals.

Mangrove lagoons can contain coral that survives in extremely hostile environments, while nearby coral reefs bleach in marine heatwaves.
Emma Camp, Author provided

While coral cover was often low and the rate at which they build their skeleton was reduced, there were established coral colonies capable of surviving in these conditions.

The success of these corals reflect their ability to adapt to daily or weekly conditions, and also their flexible relationship with various symbiotic micro-algae that provide the coral with essential resources.

While we are still in the early phases of understanding exactly how these corals can aid conservation, extreme mangrove coral populations hold a reservoir of stress-hardened corals. Notably the geographic size of these mangrove locations are small, but they have a disproportionately high conservation value for reef systems.




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Heat-tolerant corals can create nurseries that are resistant to bleaching


However, identification of these pockets of extremely tolerant corals also challenge our understanding of coral resilience, and of the rate and extent with which coral species can resist stress.The Conversation

Emma F Camp, DECRA & UTS Chancellor’s Research Fellow, Climate Change Cluster, Future Reefs Research Programe, University of Technology Sydney and David Suggett, Associate Professor in Marine Biology, University of Technology Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Extreme weather caused by climate change has damaged 45% of Australia’s coastal habitat



Bleached staghorn coral on the Great Barrier Reef. Many species are dependent on corals for food and shelter.
Damian Thomson, Author provided

Russ Babcock, CSIRO; Anthony Richardson, The University of Queensland; Beth Fulton, CSIRO; Eva Plaganyi, CSIRO, and Rodrigo Bustamante, CSIRO

If you think climate change is only gradually affecting our natural systems, think again.

Our research, published yesterday in Frontiers in Marine Science, looked at the large-scale impacts of a series of extreme climate events on coastal marine habitats around Australia.

We found more than 45% of the coastline was already affected by extreme weather events caused by climate change. What’s more, these ecosystems are struggling to recover as extreme events are expected to get worse.




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There is growing scientific evidence that heatwaves, floods, droughts and cyclones are increasing in frequency and intensity, and that this is caused by climate change.

Life on the coastline

Corals, seagrass, mangroves and kelp are some of the key habitat-forming species of our coastline, as they all support a host of marine invertebrates, fish, sea turtles and marine mammals.

Our team decided to look at the cumulative impacts of recently reported extreme climate events on marine habitats around Australia. We reviewed the period between 2011 and 2017 and found these events have had devastating impacts on key marine habitats.

Healthy kelp (left) in Western Australia is an important part of the food chain but it is vulnerable to even small changes in temperature and particularly slow to recover from disturbances such as the marine heatwave of 2011. Even small patches or gaps (right) where kelp has died can take many years to recover.
Russ Babcock, Author provided

These include kelp and mangrove forests, seagrass meadows, and coral reefs, some of which have not yet recovered, and may never do so. These findings paint a bleak picture, underscoring the need for urgent action.

During this period, which spanned both El Niño and La Niña conditions, scientists around Australia reported the following events:

2011: The most extreme marine heatwave ever occurred off the west coast of Australia. Temperatures were as much as 2-4℃ above average for extended periods and there was coral bleaching along more than 1,000km of coast and loss of kelp forest along hundreds of kilometres.

Seagrasses in Shark Bay and along the entire east coast of Queensland were also severely affected by extreme flooding and cyclones. The loss of seagrasses in Queensland may have led to a spike in deaths of turtles and dugongs.

2013: Extensive coral bleaching took place along more than 300km of the Pilbara coast of northwestern Australia.

2016: The most extreme coral bleaching ever recorded on the Great Barrier Reef affected more than 1,000km of the northern Great Barrier Reef. Mangrove forests across northern Australia were killed by a combination of drought, heat and abnormally low sea levels along the coast of the Gulf of Carpentaria across the Northern Territory and into Western Australia.

2017: An unprecedented second consecutive summer of coral bleaching on the Great Barrier Reef affects northern Great Barrier Reef again, as well as parts of the reef further to the south.

Heritage areas affected

Many of the impacted areas are globally significant for their size and biodiversity, and because until now they have been relatively undisturbed by climate change. Some of the areas affected are also World Heritage Areas (Great Barrier Reef, Shark Bay, Ningaloo Coast).

Seagrass meadows in Shark Bay are among the world’s most lush and extensive and help lock large amounts of carbon into sediments. The left image shows healthy seagrass but the right image shows damage from extreme climate events in 2011.
Mat Vanderklift, Author provided

The habitats affected are “foundational”: they provide food and shelter to a huge range of species. Many of the animals affected – such as large fish and turtles – support commercial industries such as tourism and fishing, as well as being culturally important to Australians.

Recovery across these impacted habitats has begun, but it’s likely some areas will never return to their previous condition.

We have used ecosystem models to evaluate the likely long-term outcomes from extreme climate events predicted to become more frequent and more intense.

This work suggests that even in places where recovery starts, the average time for full recovery may be around 15 years. Large slow-growing species such as sharks and dugongs could take even longer, up to 60 years.

But extreme climate events are predicted to occur less than 15 years apart. This will result in a step-by-step decline in the condition of these ecosystems, as it leaves too little time between events for full recovery.

This already appears to be happening with the corals of the Great Barrier Reef.

Gradual decline as things get warmer

Damage from extreme climate events occurs on top of more gradual changes driven by increases in average temperature, such as loss of kelp forests on the southeast coasts of Australia due to the spread of sea urchins and tropical grazing fish species.

Ultimately, we need to slow down and stop the heating of our planet due to the release of greenhouse gases. But even with immediate and effective emissions reduction, the planet will remain warmer, and extreme climatic events more prevalent, for decades to come.

Recovery might still be possible, but we need to know more about recovery rates and what factors promote recovery. This information will allow us to give the ecosystems a helping hand through active restoration and rehabilitation efforts.




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More than 28,000 species are officially threatened, with more likely to come


We will need new ways to help ecosystems function and to deliver the services that we all depend on. This will likely include decreasing (or ideally, stopping) direct human impacts, and actively assisting recovery and restoring damaged ecosystems.

Several such programs are active around Australia and internationally, attempting to boost the ability of corals, seagrass, mangroves and kelp to recover.

But they will need to be massively scaled up to be effective in the context of the large scale disturbances seen in this decade.The Conversation

Mangroves at the Flinders River near Karumba in the Gulf of Carpentaria. The healthy mangrove forest (left) is near the river while the dead mangroves (right) are at higher levels where they were much more stressed by conditions in 2016. Some small surviving mangroves are seen beginning to recover by 2017.
Robert Kenyon, Author provided

Russ Babcock, Senior Principal Research Scientist, CSIRO; Anthony Richardson, Professor, The University of Queensland; Beth Fulton, CSIRO Research Group Leader Ecosystem Modelling and Risk Assessment, CSIRO; Eva Plaganyi, Senior Principal Research Scientist, CSIRO, and Rodrigo Bustamante, Research Group Leader , CSIRO

This article is republished from The Conversation under a Creative Commons license. Read the original article.

‘Sadness, disgust, anger’: fear for the Great Barrier Reef made climate change feel urgent



Tourists are experiencing ‘Reef grief’.
Matt Curnock, Author provided

Matt Curnock, CSIRO and Scott Heron, James Cook University

Media coverage of mass coral bleaching on the Great Barrier Reef may have been a major tipping point for public concerns around climate change, according to research published today.

Severe and extensive bleaching during the summers of 2016 and 2017 has been directly attributed to human-caused climate change. Much of the ensuing media coverage used emotional language, with many reports of the Reef dying.




Read more:
Back-to-back bleaching has now hit two-thirds of the Great Barrier Reef


While the physical effects of the bleaching have been well documented, we wanted to understand the social and cultural impact.

Our research, including a study published today in Nature Climate Change, has compared survey responses from thousands of Australians and international visitors, before and after the bleaching event.

Reef grief

Our research team conducted face-to-face interviews with 4,681 visitors to the Great Barrier Reef region, in 14 coastal towns from Cooktown to Bundaberg, over June to August in both 2013 and 2017. We asked more than 50 questions about their perceptions and values of the Reef, as well as their attitudes towards climate change.

We found a large proportion of respondents, including Australians and overseas visitors, expressed forms of grief in response to loss and damage to the iconic ecosystem. Negative emotions associated with words given in short statements about “what the Great Barrier Reef means to you”, included sadness, disgust, anger and fear.




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Hope and mourning in the Anthropocene: Understanding ecological grief


Emotional appeals are widely used in media stories and in social media campaigns, and appealing to fear in particular can heighten a story’s impact and spread online.

However, a side-effect of this approach is the erosion of people’s perceived ability to take effective action. This is called a person’s “self-efficacy”.
This effect is now well documented in reactions to representations of climate change, and is actually a barrier to positive community engagement and action on the issue.

In short, the more afraid someone is for the Great Barrier Reef, the less they may feel their individual efforts will help to protect it.

While our results show a decline in respondents’ self-efficacy, there was a corresponding increase in how highly they valued the Reef’s biodiversity, its scientific heritage and its status as an international icon. They were also more willing to support action to protect the Reef. This shows widespread empathy for the imperilled icon, and suggests greater support for collective actions to mitigate threats to the Reef.

Researchers surveyed thousands of visitors to the Great Barrier Reef in 2013 and 2017.
Matt Curnock, Author provided

Changing attitudes

We observed a significant increase in the proportion of people who believe that climate change is “an immediate threat requiring action”. In 2013 some 50% of Australian visitors to the Great Barrier Reef region agreed climate change is an immediate threat; in 2017 that rose to 67%. Among international visitors, this proportion was even higher (64% in 2013, rising to 78% in 2017).

This represents a remarkable change in public attitudes towards climate change over a relatively short period. Previous surveys of Australian climate change attitudes over 2010 to 2014 showed that aggregate levels of opinion remained stable over that time.

Comparing our findings with other recent research describing the extent of coverage and style of reporting associated with the 2016-2017 mass coral bleaching event, we infer that this event, and the associated media representations, contributed significantly to the shift in public attitudes towards climate change.

Moving beyond fear

As a source of national pride and with World Heritage status, the Great Barrier Reef will continue to be a high profile icon representing the broader climate change threat.

Media reports and advocacy campaigns that emphasise fear, loss and destruction can get attention from large audiences who may take the message of climate change on board.

But this does not necessarily translate into positive action. A more purposeful approach to public communication and engagement is needed to encourage collective activity that will help to mitigate climate change and reduce other serious threats facing the Reef.

Examples of efforts that are underway to reduce pressures on the Reef include improvements to water quality, control of crown-of-thorns starfish outbreaks, and reducing poaching in protected zones. Tourism operators on the Reef are also playing an important role in restoring affected areas, and are educating visitors about threats, to improve Reef stewardship.

Clearly there remains an immediate need to reduce greenhouse gas emissions to ensure the Reef’s World Heritage qualities are maintained for future generations.

However, maintaining hope, and offering accessible actions towards attainable goals is critical to engaging people in collective efforts, to help build a more sustainable future in which coral reefs can survive.


The authors would like to acknowledge Nadine Marshall, who co-wrote this article while employed by CSIRO. We thank our other co-authors of the Nature Climate Change paper, including Lauric Thiault (National Center for Scientific Research, PSL Université Paris), Jessica Hoey and Genevieve Williams (Great Barrier Reef Marine Park Authority), Bruce Taylor and Petina Pert (CSIRO Land and Water) and Jeremy Goldberg (CSIRO & James Cook University). The scientific results and conclusions, as well as any views or opinions expressed herein, are those of the authors and do not necessarily reflect those of the Australian Government or the Minister for the Environment, or the Queensland Government, or indicate commitment to any particular course of action.The Conversation

Matt Curnock, Social Scientist, CSIRO and Scott Heron, Senior Lecturer, James Cook University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

‘Bright white skeletons’: some Western Australian reefs have the lowest coral cover on record


Corals at Scott Reef in 2012, and at the same site during the 2016 mass bleaching.
James Gilmour/AIMS

James Paton Gilmour, Australian Institute of Marine Science and Rebecca Green, University of Western Australia

Diving on the remote coral reefs in the north of Western Australia during the world’s worst bleaching event in 2016, the first thing I noticed was the heat. It was like diving into a warm bath, with surface temperatures of 34⁰C.

Then I noticed the expanse of bleached colonies. Their bright white skeletons were visible through the translucent tissue following the loss of the algae with which they share a biological relationship. The coral skeletons had not yet eroded and collapsed, a grim reminder of what it looked like just a few months before.

I spent the past 15 years documenting the recovery of these reefs following the first global coral bleaching event in 1998, only to see them devastated again in the third global bleaching event in 2016.




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Western Australia’s coral reefs are in trouble: we mustn’t ignore them


The WA coral reefs may not be as well known as the Great Barrier Reef, but they’re just as large and diverse. And they too have been affected by cyclones and coral bleaching. Our recent study found many WA reefs now have the lowest coral cover on record.

When my colleague, Rebecca Green, witnessed that mass bleaching for the first time, she asked me how long it would take the reefs to recover.

“Probably not in my lifetime” was my reply – an abrupt but accurate reply considering the previous rate of recovery, future increases in ocean temperatures … and my age.

The worst mass bleaching on record

A similar scene is playing out around the world as researchers document the decline of ecosystems they have spent a lifetime studying.

Our study, published in the journal Coral Reefs, is the first to establish a long-term history of changes in coral cover across eight reef systems, and to document the effects of the 2016 mass bleaching event at 401 sites across WA.




Read more:
The third global bleaching event took its toll on Western Australia’s super-corals


Given the vast expanse of WA coral reefs, our assessment included data from several monitoring programs and researchers from 19 institutions.

These reefs exist in some of the most remote and inaccessible parts of the
world, so our study also relied on important observations of coral bleaching from regional managers, tourist operators and Bardi Jawi Indigenous Rangers in the Kimberley.

Our aim was to establish the effects of climate change on coral reefs along Western Australia’s vast coastline and their current condition.

The heat stress in 2016 was the worst on record, causing mass bleaching and large reductions in coral cover at Christmas Island, Ashmore Reef and Scott Reef. This was also the first time mass bleaching was recorded in the southern parts of the inshore Kimberley region, including in the long oral history of Indigenous Australians who have managed this sea-country for thousands of years.

The mass bleaching events we documented were triggered by a global increase in temperature of 1⁰C above pre-industrial levels, whereas temperatures are predicted to rise by 1.5⁰C between 2030 and 2052.

In that scenario, the reefs that have bleached badly will unlikely have the capacity to fully recover, and mass bleaching will occur at the reefs that have so far escaped the worst impacts.




Read more:
The world’s coral reefs are in trouble, but don’t give up on them yet


The future of WA’s coral reefs is uncertain, but until carbon emissions can be reduced, coral bleaching will continue to increase.

Surviving coral reef refuges must be protected

The extreme El Niño conditions in 2016 severely affected the northern reefs, and a similar pattern was seen in the long-term records.

The more southern reefs were affected by extreme La Niña conditions – most significantly by a heatwave in 2011 that caused coral bleaching, impacted fisheries and devastated other marine and terrestrial ecosystems.

Since 2010, all of WA’s reefs systems have bleached at least once.

Frequent bleaching and cyclone damage have stalled the recovery of reefs at Shark Bay, Ningaloo and at the Montebello and Barrow Islands. And coral cover at Scott Reef, Ashmore Reef and at Christmas Island is low following the 2016 mass bleaching.

In fact, average coral cover at most (75%) reef systems is at or near the lowest on record. But not all WA reefs have been affected equally.

In 2016 there was little (around 10%) bleaching recorded at the northern inshore Kimberley Reefs, at the Cocos Keeling Islands, and at the Rowley Shoals. Coral cover and diversity at these reefs remain high.

And during mass bleaching there were patches of reef that were less affected by heat stress.

These patches of reef will hopefully escape the worst impacts and retain moderate coral cover and diversity as the world warms, acting as refuges. There are also corals that have adapted to survive in parts of the reef where temperatures are naturally hotter.

Some reefs across WA will persist, thanks to these refuges from heat stress, their ability to adapt and to expand their range. These refuges must be protected from any additional stress, such as poor water quality and overfishing.




Read more:
Even the super-corals of Australia’s Kimberley are not immune to climate change


In any case, the longer it takes to curb carbon emissions and other pressures to coral reefs, the greater the loss will be.

Coral reefs support critical food stocks for fisheries around the world and provide a significant contribution to Australia’s Blue Economy, worth an estimated A$68.1 billion.

We are handing environmental uncertainty to the next generation of scientists, and we must better articulate to everyone that their dependence on nature is the most fundamental of all the scientific concepts we explore.The Conversation

James Paton Gilmour, Research Scientist: Coral Ecology, Australian Institute of Marine Science and Rebecca Green, Postdoctoral research associate, University of Western Australia

This article is republished from The Conversation under a Creative Commons license. Read the original article.