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

Verena Schoepf, University of Western Australia

Coral reefs around the world are in trouble because of climate change and other pressures such as overfishing, pollution and outbreaks of coral-eating predators. Currently, they are in the spotlight because a mass bleaching event on global scale has been declared – the third since records started in the 1980s.

As mass bleaching events become more common due to rising ocean temperatures, it is increasingly urgent to understand what makes corals resistant to heat stress and climate change.

Natural laboratories

Naturally extreme environments such as the Kimberley region in northwest Australia are ideal laboratories to study this question. My colleagues and I reveal in research published today in Scientific Reports that the highly fluctuating temperatures in these extreme environments boost the ability of coral to cope with heat stress – but they do not provide immunity to bleaching.

The Kimberley region is a fascinating place: largely unspoiled and abounding with coral reefs despite conditions that would be deadly to the majority of coral elsewhere on the planet. This is because the Kimberley has the largest tropical tides in the world, up to 10 metres!

As a consequence, intertidal coral communities often get exposed to air for several hours during low tide and also experience mid-day temperatures up to 37°C for short periods of time. In contrast, maximum summer temperatures on most coral reefs elsewhere rarely exceed 30°C.

Intertidal coral communities in the Kimberley exposed during low tide. Copyright: Steeve Comeau.

The “super-corals” living in the nearshore Kimberley are adapted to these extreme conditions and likely have not experienced any major bleaching events in the past according to the Bardi Jawi people, the Traditional Owners at our field site in Cygnet Bay. This made us wonder whether adaptation to such environmental extremes has made corals more resistant to bleaching and climate change – a compelling idea that we wanted to test.

Why corals bleach

Coral bleaching occurs when corals suffer from heat stress and expel the microscopic symbiotic algae that live inside their tissue. Since the algae not only give coral most of their colour but also the majority of their food energy, bleached corals are essentially starving and can die if water temperatures remain hot for too long.

Bleached but still alive staghorn coral. Copyright: XL Catlin Seaview Survey.

We tested the heat tolerance of nearshore Kimberley corals in a tank experiment, where we simulated a bleaching event by heating the water in some of the tanks 2-3°C above the corals’ typical summer temperatures. Such temperatures are already encountered during marine heatwaves today and could become “normal” summer temperatures by the year 2100.

To our surprise, even the “super-corals” started to show signs of bleaching within only a few days – but some corals were more resistant than others.

Coral bleaching tank experiment at Cygnet Bay Pearl Farm. Copyright: Verena Schoepf.

Heat resistance

Corals from tide pools which regularly experience exposure to air, stagnant water, and temperature extremes coped with the hot water much better than corals from below the low-tide mark, where conditions are far more moderate. This shows that highly-variable, extreme temperature environments can boost the bleaching resistance of corals.

The microscopic symbiotic algae inside corals also influence how a coral reacts to heat stress. Although some types of algae can withstand hot water better than others, we found that all corals in our experiment harboured algae from a group that isn’t particularly known for its stress resistance. This confirmed the important role that the environment plays in determining coral resilience to climate-driven stresses.

Finally, corals occur in a myriad of growth forms, including branching, mounding, plating, massive and even encrusting types. In our study, branching staghorn corals bleached sooner than massive corals and many of them died, whereas all massive corals survived.

This type of bleaching pattern is typical for most coral reefs in the world. Unfortunately, the more heat-sensitive staghorn corals are the dominant corals on Indo-Pacific reefs, which is partly why mass bleaching events result in such wide-spread coral mortality.

Good and bad news for the future

Our results offer a mix of good and bad news for future coral reefs. Since extreme temperature environments boost the heat resistance of corals, they could potentially serve as temporary refuges from climate change. Corals in these environments could also recover faster from bleaching and thus potentially help to repopulate coral reefs that are hit harder.

The bad news is that even super-corals from extreme environments nevertheless remain vulnerable to severe heat stress events. As such events are becoming more frequent, it is unclear whether corals will be able to adapt fast enough to keep pace with global warming.

The current global bleaching event is a foretaste of what is to come. Repeated bleaching events have already led to significant coral deaths and reef decline in places such as the Persian/Arabian Gulf.

However, even when it comes to annual bleaching, some corals are more resistant than others and can recover quickly, as some of my past research has shown. And in the Kimberley, off-shore reefs recovered quickly after the first recorded global bleaching event in 1998 due to their isolated location.

While there is enough reason to be alarmed about the future of coral reefs, obituaries may be premature. Future coral reefs will likely be severely degraded, but there is hope that these cities under the sea will persist for many more decades.

Chances are that the super-corals from the Kimberley will be among the stalwart survivors.

The Conversation

Verena Schoepf, Research Associate, University of Western Australia

This article was originally published on The Conversation. Read the original article.


The spectacular peacock spider dance and its strange evolutionary roots

Michael Kasumovic, UNSW Australia; Damian Elias, University of California, Berkeley, and Madeline Girard, University of California, Berkeley

With their flamboyant dress, and fabulous song and dance routines, tiny peacock spiders have captivated the hearts of the internet.

Many species have courtship displays, but few are as complex as that of the peacock spider. But why does this little Casanova put on such a spectacular show, particularly when we’d expect evolution to favour simplicity?

We set up an elaborate experiment to find out. But before we raise the curtain on that, we need to set the scene.

What’s in a signal?

Imagine a high school suitor picking up his date for the prom, and we might picture him exiting a limousine wearing a tux with bouquet in hand. We’d argue (and he’d likely agree) that each of these things improves his chances of impressing his date.

But what kind of information is his date gleaning from these signals? Is he trying to make sure that his date notices that he can afford extravagance, and therefore, he’s signalling his wealth and success? Or does the car signal his wealth, his tux his desire to look good, and his flowers his love for nature? If so, then these aspects work together to signal his overall suitability as a mate.

Regardless of what motivated his signals, we’d probably all agree that that this wide-eyed youngster is trying to impress his date. But is this true? Isn’t it just as likely that this extravagance is signalling to other males that they should stay away? Or is it just the social norm to appear in a limo with a tux and flowers, otherwise he’d look out of place?

This is the problem biologists have faced when trying to explain the existence of complex courtship that uses multiple traits: what is driving a male’s improved dress and his desire to impress?

The answer has escaped biologists because single, simple traits are generally the norm. Sometimes we have species that use multiple traits, like the colourful plumage and elaborate dances of some birds, but the use of multiple traits is very rare.

Biologists’ favourite example of courtship complexity is the birds of paradise.

With 39 different species, there is a diversity of vocal signalling, extreme variation in colouration and dances that accompany both. But despite our desire to explain this diversity as a result of female preference, there is no such evidence. Until now.

The extreme variation in courtship found in birds of paradise, and the difficulty in observing them.

Along came a spider

Peacock spiders (Maratus volans) are a group that is unique to Australia. With more than 40 documented species, and likely many more to discover, it is an example where citizen science is helping us understand the diversity in this group.

It is this diversity, abundance and their extroverted courtship behaviour in the lab that really allows us to explore why such complexity exists and what it means.

You can see the camera above the mating arena surrounded with acetate to provide a safe habitat for them to court. The laser virbrometer is just behind Maddie Girard.
Maddie Girard

So to explore peacock spider courtship, we collected 128 male and female spiders from around Sydney and brought them back into the lab. Then by creating a courtship arena consisting of nylon stretched over a wooden frame and naturalising it with some leaves, we were able to record the behaviours using a video camera and the vibrational songs that males produce using a laser vibrometer.

What we found was rather interesting. We discovered that males use several different aspects to court a female.

A video of a different components of the courtship males use to court a female.

Males use vibrations early on to gain a females attention. When they are sure she’s watching, they begin to escalate courtship by waving their front legs and showing off their fan. If the female begins ignoring the male, they change their strategy and begin vibrating more.

We found that there was a very low success rate: only 16 of the 64 males were successful! And it was visual signalling effort that best predicted success – so the tux was more effective than the serenade. It was the males that were best able to show off their fans while ensuring that females were constantly watching.

Our other interesting finding was that females were very clear about what they didn’t like. During courtship, if a female signalled her displeasure by waving their abdomen back and forth, there was a low chance of success. Males therefore received feedback to their performance. So it seems that being attentive pays off.

The low success rate when courting virgin females (and potential death), coupled with the fact that none of our mated females re-mated suggests that success is very low in nature and only the males that best show off their stuff succeed.

A displeased female Maratus volans that’s taken it out on her suitor.
Maddie Girard

What we can learn from little spiders

Female peacock spiders are picky, and it’s this scrupulous behaviour that has likely led to the strong selection for the complexity of male courtship.

Understanding this is important because it provides us with insight into the evolution of traits as signals and the situations necessary for such complexity to evolve. These answers have eluded biologists so far because natural variation in the success of courting males is extremely difficult to observe.

The next step is to explore whether the species that show increased complexity have even pickier females.

But for know, we can learn from these little Aussie wonders and say that if you’re strutting your stuff on the dance floor or through virtual interactions on the internet, pay attention to what the female has to say. Perhaps you may increase your chances as you’ll know where to put your effort.

Check out the video below to learn more about Maddie and some of the diversity in courtship from other species.

The diversity of courtship from other species of Maratus produced by SciFri.

The Conversation

Michael Kasumovic, Evolutionary Biologist, ARC Future Fellow, UNSW Australia; Damian Elias, Assistant Professor in Evolutionary Biology, University of California, Berkeley, and Madeline Girard, PhD student in evolutionary biology, University of California, Berkeley

This article was originally published on The Conversation. Read the original article.

Two days in at COP21 – what has Australia pledged?

David Holmes, Monash University

The first day of the Paris climate summit was a little different to past summits. For a start, the hosts decided to bring the leaders in as an opener rather than at the end.

At first glance this decision does not make sense. But considering that the approach all along has been to get the 190 participating countries to make their pledges upfront – and even getting a first draft of an agreement nailed down in the first week – the leaders may as well get their press conferences over with.

However, other than simply spelling out what their pledges are – dressed up with the usual enlightenment language of innovation and imagination – there was not a great deal to say. Nevertheless, the mere presence of these leaders was a spectacle to behold.

The security and the media circus that surrounded them are stories in themselves. Sometimes the security arrangements got in the way – a motorcade here and a reschedule there meant that journalists couldn’t get through a cordon of police to hear the leaders of their countries make statements in one of the disused aircraft hangers that is housing everyone.

But there were several clear COP21 initiatives that were declared on day one to take advantage of head-of-state support. The standouts were an “innovation mission”, a “fossil fuel subsidy reform program”, and a project to “invest in resilience for developing countries”.

The innovation mission involving 20 major economies is one that Australia supports. The nations taking part already contribute to 80% of global clean energy research and development (R&D) budgets, which they have pledged to double from US$10 billion to $20 billion over five years. If the R&D money is used in parallel with existing renewables technology, it is a potentially transformational project.

Bill Gates also got up at this announcement – which I attended – along with Barack Obama, Narendra Modi and Francois Hollande, to reveal that 28 large investors from ten countries have joined the coalition of supporters.

Gates said that there were two initiatives being introduced:

… increased government research and private investment are to address climate change and to reduce the cost of energy to reduce poverty. We need to move to sources of energy that the hydrocarbon energy that we use today.

However, at an activist side-event held the next day, Naomi Klein said that while Gates had good intentions, we need to get out of the binary that the climate crisis can only be solved by:

… top-down corporate solutions vs bottom-up justice solutions.

Klein asked:

What about funding of more public transport or for decentralised renewable power?

Klein followed many activists who have rejected the way corporates have to look only to a pioneering discourse that myths are made of, whereby it is only the heroic visions of a few rich people that can save the planet.

However, the Mission Innovation countries are happy for corporates to take on risk for these projects and have released a joint statement detailing their initiative. The group includes Australia, Brazil, Canada, Chile, China, Denmark, France, Germany, India, Indonesia, Italy, Japan, Mexico, Norway, Republic of Korea, Saudi Arabia, Sweden, the UK, the UAE and the US.

But an initiative that Australia has stayed well away from is undoubtedly the fossil fuel subsidy reform program. This is curiously being led by New Zealand, which is not known for having a recognisable mining sector.

For Australia to cop out on this initiative is not surprising – but it is also very serious. Australian taxpayers subsidise the fossil fuel industry to the tune of to A$182 per taxpayer every year. A gigantic sum of $9.4 billion over the next four years will be handed out to the most profitable fossil fuel companies in Australia.

So captive is Australia to “big coal” in particular – which donates to both major political parties – that this kind of reform looks a long way off in Australia. Nevertheless, in the communique – which was ceremonially handed over to the UNFCCC head Christina Figueres – New Zealand Prime Minister John Key explains that even a partial phas eout of fossil fuel subsidies would generate 12% of the total abatement needed by 2020 to keep the door open to the 2°C target.

Notwithstanding Key’s leadership, New Zealand was awarded the “Fossil of the Day” by the Climate Action Network (representing 950 NGOs). In a flyer leafleted to the largest newsroom in the world, the network pointed out that New Zealand has increased fossil fuel subsidies seven-fold since Key was elected in 2008. But at least he is getting other countries to do some heavy lifting.

Just one desk at the largest news room in the world.
David Holmes

Another initiative that Australia has not joined is the Global Environment Facility – a fund to which 11 developed countries have signed up to with US$248 million in funding to go to adaptation support for the most vulnerable countries on the planet.

The US is a supporter, and President Barack Obama said on day one:

For some, particularly island nations […], climate change is a threat to their very existence. That’s why today, in concert with other nations, America confirms our strong and ongoing commitment to the Least Developed Countries Fund. And tomorrow, we’ll pledge new contributions to risk insurance initiatives that help vulnerable populations rebuild stronger after climate related disasters.

Perhaps Australia never signed up to this as it was being negotiated during the time of the former Abbott government, which cut overseas aid. But, at Turnbull’s statement on Monday, the standout pledge that was made was that:

Australia will contribute at least $1 billion over the next five years from our existing aid budget both to build climate resilience and reduce emissions.

This really is a large sum compared to the Global Environment Facility nations, and is an example of Australia taking proportional responsibility for climate change. And it is also appropriate given Australia’s proximity to sea level rise-affected nations in the pacific.

According to Oxfam, which is represented at the conference, the world’s richest 10% produce half of carbon emissions, while the poorest 3.5 billion account for only 10%. The problem here is that the poorest countries are actually the most vulnerable.

Because of this, a coalition has emerged at the conference of 105 of the most vulnerable countries that are after a 1.5℃ limit to global temperature rise. This gives them a majority power bloc on this figure. As Saleemul Huq from the International Centre for Climate Change and Development said on Tuesday, if the UNFCCC was a democracy:

We would win.

The dramatic inequity between the rich and poor nations looms to be the greatest fissure in any agreement.

Australia is placed firmly on the rich, high-polluter side of the ledger. At an OECD side event on Tuesday entitled “Climate Change mitigation: policies and progess”, the OECD’s director of environment, Simon Upton, put up a website on screen that allows OECD countries to compare their per capita status and emissions intensity. Australia’s emissions stand out acutely.

But with this as a backdrop, Environment Minister Greg Hunt, who is here for the first week, looked particularly uncomfortable. He reiterated his phrase that Australia is reducing emissions while blithely dismissive the scale of our domestic and exported emissions. Earlier in the day he had confirmed that Australia would ratify the second part of the Kyoto protocol – subject to cabinet and partyroom approval.

But Hunt had to field the most questions from the audience, which declared that the international community was getting “mixed messages” about its carbon abatement strategies. On the one hand, the mantra of “meeting and beating” such a paltry set of targets is Hunt’s main way of absolving Australia’s stance.

Paolo Frankl from the International Energy Agency was asked by The Guardian’s Lenore Taylor whether a country can achieve a long-term reduction in abatement pricing without an emissions trading scheme. He replied:

Well it can, but it would not be very useful. If you look at Brazil and Australia that is exactly what they are doing now. But in addition to that, there should be a carbon price which would give an additional signal.

Then Hunt had to field a question about the Carmichael mine, and the contradiction that while Australia is meeting and beating an antiquated target, it is exporting embedded emissions that dwarf its domestic emissions. Hunt sought to disown the project by saying that it is not an “Australian government project”, it’s a private firm from India. He said:

Mostly I thought we are over the neocolonial moment where the wealthy decides what happens to the poor.

I think it is the poorest that should be able to make their own decisions.

The problem here is that it is not “India” that is making the decision, but a local multi-billion elite in the form of Adani.

If Hunt really is “over” the neocolonial moment then he is bound to agree with those 105 poorest countries that are pressing for a 1.5℃ guardrail. But that is one figure that the entire conference, let alone Hunt, is not going to meet and beat with the current pledges.

The Conversation

David Holmes, Senior Lecturer, Communications and Media Studies, Monash University

This article was originally published on The Conversation. Read the original article.

Australia is set to ratify the second part of Kyoto Protocol – but it’s not a done deal

Ben Parr, University of Melbourne

Prime Minister Malcolm Turnbull’s pledge overnight in Paris that Australia will ratify the second phase of the Kyoto Protocol is welcome news.

The first phase of the Kyoto Protocol commenced in 2008 and concluded in 2012. In November 2007, in his first act as prime minister, Kevin Rudd ratified this phase, committing Australia to an emissions target to limit greenhouse gas emissions to 8% above 1990 levels over the 2008-2012 period.

The second phase of the Kyoto Protocol covers the period 2013 to 2020. This was agreed to by the parties to the Kyoto Protocol, including Australia, at the United Nations climate talks in Doha in 2012.

Turnbull’s pledge commits Australia to a 5% reduction in greenhouse gas emissions below 2000 levels in the second phase.

Presently, 54 countries have submitted their instruments of acceptance to the second commitment phase of the Kyoto Protocol. To enter into force however, three quarters of the nations to the Protocol will have to submit, which means 144 nations out of 192.

Australia’s pledge to ratify the second phase may encourage other countries to do the same. Alternatively, Australia’s low 2020 target, which some say is out-of-step with the rest of the world and the science of climate change, may simply further frustrate some developing countries. These countries are already very concerned that industrialised counties are continuing to side-step their leadership obligations under the existing UN climate regime.

Turnbull’s pledge comes as Australia’s new prime minister seeks to distinguish his government from his predecessor on this issue. This new tack is also consistent with Turnbull’s new positive message about opportunities and innovation, and with his previous position on climate as opposition leader in 2009.

This step means that the Turnbull government is locked into an emissions reduction target, but not the method of how to achieve it.

Not a done deal

Ultimately, Australia’s international policy position on climate change is determined by domestic politics.

In Australia’s political system ratifying international treaties, which includes the Kyoto Protocol Mark I and II, does not require any formal legislative approval. The final decision rests at a ministerial level, and ultimately the prime minister, with a keen eye to the mood of the party room.

Environment minister Greg Hunt said this morning that “Australia will ratify Kyoto II with the support of the cabinet and party room”. So it seems that this base is covered, for now. Indeed some in the Liberal party room are already warning against target increases.

The parliamentary oversight that does exist for treaties, for instance the Joint Standing Committee on Treaties, is relatively weak, usually acting as a rubber stamp. So this aspect seems to be covered.

If Australia does ratify the second phase of the Kyoto Protocol, it is entirely possible that sometime between now and 2020 we will see a switch to an emissions trading scheme (ETS), which would of course require the passage of a new bill through both houses of parliament.

The Climate Change Authority’s second draft report of Australian climate policy released yesterday required the authority to consider whether an ETS would harm Australia’s international competitiveness. This may mean designing an ETS that allows liable polluting firms to import an unlimited number of cheap international carbon credits to meet their emissions caps, reducing the incentive to clean up domestic production processes. We saw this previously under the Rudd-Turnbull Carbon Pollution Reduction Scheme.

Other domestic constraints over national climate policies and Australia’s international negotiating positions may emerge externally from the Parliament, for example, from Australia’s fossil fuel lobby. However, public opinion, which is squarely behind strong action on climate change, may enable the government to propose stronger targets.

Obstacles abound before we get a clear picture of Australian climate policy moving forward.

The Conversation

Ben Parr, Research Fellow, Melbourne Sustainable Society Institute, University of Melbourne

This article was originally published on The Conversation. Read the original article.

New ‘vulnerable nations’ bloc looks set to redraw the climate politics map

Matt McDonald, The University of Queensland

Vulnerable states have featured prominently on the first day of Paris Climate talks. UN Secretary-General Ban Ki-Moon unveiled a new initiative to strengthen the resilience of the most vulnerable people and countries to the effects of climate change.

But it is the emergence of a bloc of 44 vulnerable countries calling for much stronger climate action that may be the real game-changer in international climate politics.

While the so-called North-South divide has long characterised international climate deliberations, there are signs it may be on its last legs in that forum. And that’s a good thing.

Ending the North-South divide?

The first major international environmental conference was the UN Conference on the Human Environment in Stockholm in 1972. By most accounts, the conference – already undermined by the status of environmental concerns as “fringe” global issues at the time – was devastated by the scale of a divide between rich and poor countries.

While the Cold War raged and the clash between East and West dominated strategic thinking and international relations, it was the North-South divide that presented the yawning chasm between participants. Some nations, most notably Brazil, raged publicly about how impoverished states were being asked to make sacrifices to address environmental issues.

Brazil’s ambassador to the United States argued forcefully, just months before the conference, that “any ecological policy, globally applied, must not be an instrument to suppress wholly or in part the legitimate right of any country to decide about its own affairs”.

It is no coincidence that the next major international environmental conference 20 years later – the 1992 Rio summit which saw the birth of the UN Framework Convention on Climate Change (UNFCCC), the agency under which the current negotiations are carried out – was held in Brazil, and officially titled the UN Conference on Environment and Development. In the framing and rationale for the conference, its organisers were acutely aware of the need to address global development inequality if the environmental agenda was even to be heard, much less practically addressed.

In many ways, it is a divide that has endured since through the UNFCCC process. The 1997 Kyoto Protocol compelled only the “global North” to commit to emissions reduction targets. Subsequent difficult deliberations around technology transfer and climate finance also centred on the rich-poor divide. These debates, which may still play out in Paris, emphasised the different responsibilities and capacities of developed and developing states to address climate change.

A new view

This is precisely why the announcement from 44 vulnerable countries that they are breaking ranks with other developing states to call for more substantial global emissions reductions, and a warming limit of 1.5℃ rather than 2℃, is so significant. Of course at the most obvious level, it complicates the simple application of the North-South divide to global politics.

But more importantly for the international politics of climate change, this new “vulnerable country” alliance’s challenge to the old divide is significant for two key reasons.

It limits the extent to which an international debate about managing the global problem of climate change might descend into a debate about global inequality. The latter is of course central for coming to terms with levels of responsibility and vulnerability, but climate change is too pressing a problem not to be addressed in its own right.

President of the Republic of the Marshall Islands Christopher Loeak addresses the summit.
Stephane Mahe/Reuters

What is needed instead is a focus on this global problem that is sensitive to differentiated development without being subsumed by it. Indeed, the need to be sensitive to developmental differences while focusing on the shared problem of climate change was already recognised in the 1992 Rio Declaration commitment to the principle of “common but differentiated responsibility”.

This challenge to the North-South divide could also deal a fundamental blow to the broader determination of some to cast environment and development imperatives as mutually exclusive. Economic growth in a number of states that have shifted towards renewable energy already, of course, illustrates how problematic this narrative is. But it is one that clings to life. The split in the global South suggests a challenge to it in ways that may effect debates beyond negotiations.

In Australia, for example, strong measures to address climate change have traditionally been denigrated for their impact on jobs and the economy, including as recently as the eve of the conference, when the government dismissed the opposition’s calls for more ambitious emissions targets.

Despite the facts that such assertions consistently rely on dubious or selective economic modelling, it is a narrative that seems to have traction. But when genuinely poor states call for strong climate action, it suggests limits to the idea of these goals as mutually exclusive. At very least, countries like Australia may find it far more difficult to sustain this argument for minimal action in international deliberations, as it did in Kyoto in 1997.

There is reason to be optimistic, then, that one of the most enduring and problematic impediments to action on climate change – its adverse economic effects – is being systematically undermined. The emergence of this bloc of vulnerable countries, combined with the development of renewable energy capacity and a commitment by developed states to finance climate mitigation and adaptation in the developing word, is seriously threatening the logic on which the environment-development narrative is based.

For the sake of the environment, future generations, vulnerable populations and even long-term economic growth, that’s a good thing.

The Conversation

Matt McDonald, Associate Professor of International Relations, The University of Queensland

This article was originally published on The Conversation. Read the original article.