People and ecosystems

Understanding of the links between coral reef ecosystems, the goods and services they provide to people, and the wellbeing of human societies.


Ecosystem dynamics: past, present and future

Examining the multi-scale dynamics of reefs, from population dynamics to macroevolution


Responding to a changing world

Advancing the fundamental understanding of the key processes underpinning reef resilience.

Coral Bleaching

Coral Bleaching

Coral Reef Studies

ARC Centre of Excellence for Coral Reef Studies
James Cook University Townsville
Queensland 4811 Australia

Phone: 61 7 4781 4000
Email: info@coralcoe.org.au

Menu Image Menu Image Menu Image Menu Image Menu Image Menu Image Menu Image
Facebook Twitter YouTube FlickR

Scientists have discovered a never-before-seen biodiversity pattern of coral reef fishes that suggests some fishes might be exceptionally vulnerable to environmental change.

A new study shows plankton-eating coral reef fishes (planktivores) are far more diverse than others in the Indo-Australian Archipelago, a global marine biodiversity hotspot.

The findings highlight, for the first time, a unique link between the diet and distribution of species across the marine realm.

“The archipelago is one of the most complex and dynamic geological regions in the tropics,” said lead author Dr Ale Siqueira from the ARC Centre of Excellence for Coral Reef Studies at James Cook University (Coral CoE at JCU). “And its fishes underpin its status as a biodiversity hotspot.”

“The exceptional success of planktivores may be a result of the hotspot’s unique geological configuration and oceanographic currents, which ensure a constant and abundant source of planktonic food,” said co-author Professor David Bellwood, also from Coral CoE at JCU.

“Such stable conditions over the past five million years are likely to have promoted the accumulation of planktivorous fish species in the hotspot.”

While planktivores thrive in the hotspot, they have had a difficult history in more remote areas with the possibility of food shortages and periodic extinctions.

“Planktivore richness drops abruptly away from the marine hotspot—and more so than any of the other dietary categories studied,” Dr Siqueira said.

These findings suggest a vulnerability of planktivorous coral reef fishes to environmental change, despite their species richness within the hotspot.

“We examined the global diversity patterns for more than 3,600 coral reef fishes,” said co-author Dr Pete Cowman from Coral CoE at JCU and Queensland Museum.

Dr Cowman said the research identified a link between biodiversity, food and habitat—emphasising the importance of species interactions with their environment.

“Understanding the ecosystem roles of different species and how they have changed through space and time offers the potential for exciting new insights, as revealed by our planktivores,” Dr Cowman said.

Dr Siqueira said a deeper understanding of species interactions is needed.

“Future research should focus on the ecosystem roles that different species play,” Dr Siqueira said.

“We need to describe changes in the roles of species through space and time, rather than simply documenting species and their numbers; the traditional approach in science.”


Siqueira A, Morais R, Bellwood D, Cowman P. (2021). ‘Planktivores as trophic drivers of global coral reef fish diversity’. Proceedings of the National Academy of Sciences (PNAS). DOI: 10.1073/pnas.2019404118


A selection of images can be used for media stories with credit to Victor Huertas. Please note these are for single use with this story only, not for any other story. No archival permissions are granted.


Ale Siqueira (limited communication, please contact Melissa at end of release)
E: alexandre.siqueira@my.jcu.edu.au

David Bellwood (Townsville, Australia)
P: +61 (07) 4781 4447
E: david.bellwood@jcu.edu.au

Pete Cowman (Townsville, Australia)
P: +61 (0)490 231 223
E: peter.cowman@jcu.edu.au


Melissa Lyne / Coral CoE at JCU (Sydney, Australia)
P: +61 (0)415 514 328
E: melissa.lyne@jcu.edu.au

Scientists say stable seafood consumption amongst the world’s poorer coastal communities is linked to how local habitat characteristics influence fishing at different times of the year.

In the coastal communities of low-income countries, the seafood people catch themselves is often a main food source. In a new study, scientists focused on an often-overlooked type of fishing called gleaning: collecting molluscs, crabs, octopus and reef fish by hand close to shore.

“We surveyed 131 households in eight coastal communities on a small island off Timor-Leste,” said study lead author Ruby Grantham a PhD candidate from the ARC Centre of Excellence for Coral Reef Studies.

Grantham said even though gleaning is important for food security in rough weather—when other types of fishing often aren’t possible—some households don’t do it.

“It’s not just a case of people fishing when they need to. Weather and coastal conditions make fishing activities, including gleaning, dangerous, unsuccessful or even impossible in some places at certain times of the year,” Grantham said.

She said the findings illustrate the ways people interact with, and benefit from, coastal ecosystems. And how this varies between communities and seasons.

The study found the ability of households to glean in rough weather was influenced by the total area and type of shallow habitat close to the community.

“This highlights why we need context-specific understanding of dynamic coastal livelihoods and small-scale fisheries in particular,” Grantham said.

“Even amongst these eight communities on the same small island we found distinct differences in how and when gleaning contributes to household fishing activities and as a source of subsistence seafood.”

Co-author Dr David Mills, Research Leader for the WorldFish Country Program in Timor-Leste, said the research is important for the future management of coastal fisheries.

“In Timor-Leste, low-income households have few opportunities to access the high-quality nutrition available from seafood,” Dr Mills said.

“We know that gleaning fisheries are really important for food security at particular times of the year,” he said.

“And this detailed research will help us develop management approaches that keep fisheries sustainable while also ensuring seafood remains available to those who need it the most, when they need it the most.”

Climate change is altering the world and its environments rapidly. People depend on their interactions with nature for many aspects of wellbeing. Understanding these interactions is critical for diagnosing vulnerabilities and building resilience, especially amongst coastal communities who depend directly on healthy oceans for food.

“The success of coastal livelihood strategies depends on a range of influences that are now, at best, poorly-understood,” Grantham said.

“We wanted to explore how people interact with and benefit from coastal environments through time.”

Grantham said a better understanding of the existing relationships between people and nature, as well as how these influence interactions between societies and local ecosystems, is crucial to legitimate environmental policy and management to ensure sustainable futures.

“We need to further consider the factors influencing how feasible and how desirable social-ecological interactions, like fishing, are across different seasons,” she said.

“These insights of the fine scale dynamics in how people interact with coastal ecosystems through activities such as gleaning can help strengthen our understanding in research, decision-making and management in coastal areas exposed to environmental change.”


Grantham R, Álvarez‐Romero J, Mills D, Rojas C, Cumming G. (2021). ‘Spatiotemporal determinants of seasonal gleaning’. People and Nature. DOI: 10.1002/pan3.10179


A selection of images can be used for media stories with credit to the photographer as stated in the caption. Please note these are for single use with this story only, not for any other story. No archival permissions are granted.


Ruby Grantham (Townsville, Australia)
E: Ruby.Grantham@my.jcu.edu.au

David Mills (Townsville, Australia)
P: +61 (0) 415 067 551
E: D.Mills@cgiar.org


Melissa Lyne / Coral CoE (Sydney, Australia)
P: +61 (0)415 514 328
E: Melissa.Lyne@jcu.edu.au

An international group of scientists is predicting markedly different outcomes for different species of coral reef fishes under climate change – and have made substantial progress on picking the ‘winners and losers’.

Associate Professor Jodie Rummer from James Cook University’s ARC Centre of Excellence for Coral Reef Studies co-authored a study that exposed two species of coral reef fishes to elevated temperatures and measured their responses over time.

“We collected five-lined cardinalfish and redbelly yellowtail fusilier from the Great Barrier Reef, and under controlled conditions in the laboratory at JCU, slowly raised the temperature in their aquaria by 3.0˚C.

“This temperature range spans the average summer temperatures experienced in the northern Great Barrier Reef. We then routinely measured 18 physiological traits in both species over five weeks,” she said.

The Intergovernmental Panel on Climate Change predicts sea surface temperatures are expected to rise by 2.0–4.8˚C by the end of the 21st century, but this is also resulting in the increasing frequency and severity of extreme heatwaves experienced worldwide.

“Over just a few days, these heatwaves can increase water temperatures by as much as 5˚C above seasonal average temperatures, and such heatwaves can last for several weeks,” said Dr Rummer.

She said the fusilier exhibited rapid responses to thermal stress, with nearly immediate changes detected in gill morphology and blood parameters. But the cardinalfish response was delayed, and they seemed far less able to adjust to the elevated temperatures.

Importantly, the team identified seven parameters across both species that may be useful as biomarkers for evaluating how fast and to what extent coral reef fishes can cope with elevated temperatures.

“Our findings greatly improve our current understanding of the physiological responses associated with ongoing thermal threats and disturbances, including which species may be most at risk,” said co-author Assistant Research Professor Jacob Johansen, from the Hawaii Institute of Marine Biology.

The researchers said the study is timely, given the rapid decline of tropical coral reefs worldwide, including the unprecedented and repeated mass coral bleaching and mortality events on the Great Barrier Reef in 2016, 2017, and 2020 – all caused by summer heatwaves.

“Climate change winners and losers will ultimately be determined by their capacity to compensate for thermal stress over both the short term of days, weeks, and months, but also over the longer term of years, decades, and centuries,” said co-author Assistant Professor Lauren Nadler from Nova Southeastern University in the United States.

“Our findings are immensely useful for scientists but also for managers, conservation planners, and policy makers charged with protecting these important ecosystems, not to mention communities who rely on coral reef fishes for food, culture, jobs, and livelihoods.

“Collectively, we need to have an indication of which species are going to survive and which will be most vulnerable to climate change so we can take action. The decisions we make today will determine what coral reefs look like tomorrow,” Dr Rummer said.


Associate Professor Jodie Rummer (Townsville, AUSTRALIA)
M: 0439 166 171
E: jodie.rummer@jcu.edu.au

Assistant Professor Jacob Johansen (Manoa, Hawaii USA)
M: +1 (808) 236 7478
E: jacob.l.johansen@gmail.com

Assistant Professor Lauren Nadler (Fort Lauderdale, Florida USA)
M: +1 (954) 262 3234
E: lnadler@nova.edu


Johansen J, Nadler L, Habary A, Bowden A, Rummer J (2021). ‘Thermal acclimation of tropical coral reef fishes to global heat waves’. eLife. DOI: https://doi.org/10.7554/eLife.59162

Images here for use with this release. Not for re-use, re-sale or archiving. Please credit as marked.

New research has found as climate change causes the world’s oceans to warm, baby sharks are born smaller, exhausted, undernourished and into environments that are already difficult for them to survive in.

Lead author of the study Carolyn Wheeler is a PhD candidate at the ARC Centre of Excellence for Coral Reef Studies at James Cook University (Coral CoE at JCU) and the University of Massachusetts. She examined the effects of increased temperatures on the growth, development and physiological performance of epaulette sharks—an egg-laying species found only on the Great Barrier Reef. She and her team studied the sharks as embryos and as hatchlings.

“We tested shark embryos in waters up to 31°C,” Ms Wheeler said.

“The hotter the conditions, the faster everything happened, which could be a problem for the sharks. The embryos grew faster and used their yolk sac quicker, which is their only source of food as they develop in the egg case. This led to them hatching earlier than usual.”

This meant hatchlings were not only smaller, they needed to feed almost straight away—while lacking significant energy.

Co-author Associate Professor Jodie Rummer, also from Coral CoE at JCU, says the waters of the Great Barrier Reef will likely experience summer averages close to or even in excess of 31°C by the end of the century.

Since sharks don’t care for their eggs after they are laid, a shark egg must be able to survive unprotected for up to four months. Dr Rummer flags rising ocean temperatures as a major concern for the future of all sharks—both egg-laying and live-bearing species.

“The epaulette shark is known for its resilience to change, even to ocean acidification,” Dr Rummer said. “So, if this species can’t cope with warming waters then how will other, less tolerant species fare?” she said.

Sharks and the class of animals they belong to, which includes rays and skates, are slow growing. They also don’t reproduce that often compared to other fishes. The populations of these creatures are already threatened across the globe.

The study suggests the sharks of the future will be born—or hatch, in this case—not only at a disadvantage but into environments that are already at the warmest they can tolerate.

“The study presents a worrying future given that sharks are already threatened,” Ms Wheeler said.

“Sharks are important predators that keep ocean ecosystems healthy. Without predators, whole ecosystems can collapse, which is why we need to keep studying and protecting these creatures.”

“Our future ecosystems depend us taking urgent action to limit climate change,” Dr Rummer said.

The research was a collaborative effort between the Anderson Cabot Center for Ocean Life and the husbandry staff at the New England Aquarium in Boston. The New England Aquarium has a successful breeding program for epaulette sharks.


Wheeler C, Rummer J, Bailey B, Lockwood J, Vance S, Mandelman J. (2020). ‘Future thermal regimes for epaulette sharks (Hemiscyllium ocellatum): growth and metabolic performance cease to be optimal’. Scientific Reports, 10: 79953. DOI: 10.1038/s41598-020-79953-0


A selection of images can be used for media stories with credit to the photographer as stated in the caption. Please note these are for single use with this story only, not for any other story. No archival permissions are granted.


Carolyn Wheeler
E: carolyn.wheeler@my.jcu.edu.au

A/Prof Jodie Rummer
P: +61 (0)439 166 171
E: jodie.rummer@jcu.edu.au


Melissa Lyne / Coral CoE
P: +61 (0)415 514 328
E: melissa.lyne@jcu.edu.au

A new study shows the coastal protection coral reefs currently provide will start eroding by the end of the century, as the world continues to warm and the oceans acidify.

A team of researchers led by Associate Professor Sophie Dove from the ARC Centre of Excellence for Coral Reef Studies at The University of Queensland (Coral CoE at UQ) investigated the ability of coral reef ecosystems to retain deposits of calcium carbonate under current projections of warming and ocean acidification.

Calcium carbonate is what skeletons are made of—and it dissolves under hot, acidic conditions. Marine animals that need calcium carbonate for their skeletons or shells are called ‘calcifiers’. Hard corals have skeletons, which is what gives reefs much of their three-dimensional (3D) structure. It’s this structure that helps protect coasts—and those living on the coasts—from the brunt of waves, floods and storms. Without coral reefs the coasts ‘drown’.

A/Prof Dove says the amount of calcium carbonate within a coral reef ecosystem depends on the biomass of hard corals. But it also depends on the combined impact of warming and acidification on previously deposited calcium carbonate frameworks. She says the results of the study indicate the rate of erosion will overtake the rate of accretion on the majority of present-day reefs.

“Today’s Great Barrier Reef has a 30% calcifier cover,” A/Prof Dove said.

“If CO2 emissions aren’t curbed, by the end-of-century a 50% calcifier cover is required to counter the physical erosion they face from storms and wave impacts,” she said.

“In addition, more than 110% calcifier cover is needed to keep up with the minimal levels of sea-level rise.”

However, A/Prof Dove says both of these scenarios are unlikely because high amounts of hard corals perish with intense underwater heatwaves. Previous studies show marine heatwaves will become chronic in the warmer months of an average year under unmitigated CO2 emissions.

The study was published in today’s Communications Earth & Environment, just after the IUCN World Heritage Outlook 3 rated the Great Barrier Reef as ‘critical’.

A/Prof Dove and her team built experimental reefs closely resembling those of shallow reef slopes at Heron Island on the southern Great Barrier Reef. For 18 months, they studied the effects of future climate scenarios on the ecosystem.

“What we saw was the insidious and accelerated loss of coastal protection under unmitigated CO2 emissions,” said co-author Professor Ove Hoegh-Guldberg, also from Coral CoE at UQ.

“Under current projections, reefs will not simply adapt. Chronic exposure to the combined impacts of ocean warming and acidification will weaken reefs. They won’t be able to re-build after disturbances such as cyclones, nor will they keep up with sea-level rise—possibly for thousands of years,” said co-author Dr Kristen Brown, also from Coral CoE at UQ.

This means many coastal areas currently protected by calcareous coral reefs will no longer be so, impacting coastal infrastructure and communities.

“The combined impact of warming with the acidification of our oceans will see more than the collapse of ecosystems,” A/Prof Dove said.


Dove S, Brown K, Van Den Heuvel A, Chai A, Hoegh-Guldberg O. (2020). ‘Ocean warming and acidification uncouple calcification from calcifier biomass which accelerates coral reef decline’. Communications Earth & Environment. DOI: 10.1038/s43247-020-00054-x


These images are for single use with this story only, not for any other story. No archival permissions are granted. Please ensure all resources carry correct attribution as listed in the file name.


A/Prof Sophie Dove (Brisbane, AEST)
E: s.dove@cms.uq.edu.au

Prof Ove Hoegh-Guldberg (Brisbane, AEST)
E: oveh@uq.edu.au

Dr Kristen Brown (Brisbane, AEST)
P: +61 (0)475 073 741
E: kristen.brown@uq.edu.au


Melissa Lyne/ Coral CoE (Sydney, AEDT)
P: +61 (0)415 514 328
E: melissa.lyne@jcu.edu.au

A team of scientists led by the ARC Centre of Excellence for Coral Reef Studies (Coral CoE) won one of the nation’s top science awards at tonight’s ‘Oscars of Australian science’, the Eureka Prizes.

Professor Josh Cinner leads Social-Ecological Research Frontiers, the winner of the 2020 Eureka Prize for Excellence in Interdisciplinary Scientific Research. The international team includes scientists from seven Australian institutions, with Dr Michele Barnes, Dr Jacqui Lau, Dr Georgina Gurney, Professor Andy Hoey and PhD candidate Jessica Zamborain Mason rounding out the Coral CoE team.

“We study coral reefs bucking the trend and thriving despite climate change, over-fishing and pollution,” Prof Cinner said. “Some coral reefs have surprisingly high amounts of fish despite high human pressures. We call these reefs ‘bright spots’.”

Studying bright spots can help inform new solutions to tackle the decline of reefs worldwide. The team used a blend of social science, ecology and other disciplines to identify and learn more about these unique areas.

“Coral reefs are in crisis. We’re not going to get out of this crisis by doing more of the same,” Dr Barnes said.

She says the aim of their research was to learn from places doing things differently, by uncovering how they withstood the pressures that caused other places to collapse. These lessons are then applied to reef conservation and management in other areas.

The Social-Ecological Research Frontiers team conducted more than 6000 surveys on 2500 reefs across 46 countries.

The insights from the team’s past four years of research would have been impossible within a single discipline—uncovering and understanding bright spots required intense interdisciplinary collaboration.

“To be clear, bright spots aren’t necessarily ‘pristine’ reefs,” Prof Cinner said. “These reefs are doing better than they should be given the pressures they face—reefs that are ‘punching above their weight’.”

The results directly inform the development of fisheries management and conservation.

“Investments that support local involvement and strengthen ownership rights can foster creative solutions to help communities defy anticipated reef degradation,” Dr Lau said.

The team say while the best way to help coral reefs is to reduce greenhouse gas emissions as quickly as possible, the team hopes their work can also foster a new way of confronting the coral reef crisis.

“We hope it provides inspiration for coral reef researchers who are tired of writing obituaries,” Dr Gurney said.

“I am very honoured to accept this Eureka Prize on behalf of our team and proud of our collaboration and what we’ve achieved by working together,” Prof Cinner said.

The Australian Museum (AM) Eureka Prizes are Australia’s leading science awards. This year marks the 30th anniversary of the awards, which were held as a live, digital event with 51 finalists across 17 prizes on the evening of Tuesday 24 November 2020.


Prof Josh Cinner (Townsville, AEST)
P: + 61 (0)417 714 138
E: joshua.cinner@jcu.edu.au

Dr Michele Barnes (Townsville, AEST)
P: +61 (0)408 677 570
E: michele.barnes@jcu.edu.au

Dr Jacqueline Lau (Townsville, AEST)
P: +61 (0)403 990 738
E: jacqueline.lau@jcu.edu.au

Dr Georgina Gurney (Townsville, AEST)
E: georgina.gurney@gmail.com


Melissa Lyne / Coral CoE (Sydney, AEDT)
P: + 61 (0)414 514 328
E: melissa.lyne@jcu.edu.au

An analytical tool will be used to assess the climate risks facing historic World Heritage sites in Africa—the ruins of two great 13th century ports and the remains of a palace and iron-making industry.

Dr Scott Heron and Jon Day from the ARC Centre of Excellence for Coral Reef Studies at James Cook University (Coral CoE at JCU) developed the Climate Vulnerability Index (CVI)—an assessment tool that can be applied to all types of World Heritage properties.

“The CVI is a rapid evaluation tool that was developed to analyse climate risk for World Heritage properties by considering historical and projected climate impacts on the World Heritage values,” said Mr Day.

“It not only assesses the vulnerability of heritage values but, unlike many other tools, also looks at the vulnerability of associated communities based on their economic, social and cultural relationships to those values and their capacity to adapt,” said Dr Heron.

There are currently more than 1,100 World Heritage areas – natural, cultural and mixed – around the world.

The CVI was first applied to Shark Bay in Western Australia and has also been applied to properties in Scotland and northern Europe, with preparations underway in several other locations.

“Our analyses identified World Heritage values in many locations are at high risk to climate impacts – many of these ‘best-of-the-best’ places are already being affected,” said Dr Heron.

Now a global team, led by institutions in Africa and the United Kingdom, will apply the CVI to World Heritage properties in Africa for the first time (the CVI-Africa project).

Scientists will assess the Ruins of Kilwa Kisiwani and Songo Mnara, two trading ports on two islands off the coast of Tanzania through which much of the Indian Ocean’s trade passed between the 13th and 16th centuries, and the remains of a 16th century palace and flourishing iron industry in the valley below—at the Sukur Cultural Landscape in Nigeria.

“Despite the intensifying threat, there is a lack of attention to the cultural dimensions of climate change and this is especially true across the African continent. The CVI-Africa project will help fill this gap,” said Dr Albino Jopela of the African World Heritage Fund.

Africa is projected to warm more rapidly than most other regions in the world, meaning this already vulnerable continent will be hard-hit by the impacts of climate change.

“These climate change impacts are already resulting in the loss and damage of cultural heritage sites across Africa,” said Dr Will Megarry of Queen’s University Belfast, the project’s lead investigator.

“This loss is not limited to historical and archaeological buildings and places, it is also impacting communities and their cultural traditions. How those who care for Africa’s cultural heritage respond to the threat of climate change has profound implications for the resilience of the broader community,” said Dr Megarry.

The CVI-Africa project is made possible through a grant awarded by the UK Arts and Humanities Research Council’s Global Challenges Research Fund.

Project Website: https://cvi-africa.org/


Dr Scott Heron (Townsville)
P: +61-404-893-420
E: scott.heron@jcu.edu.au

Albino Jopela (South Africa)
P: +276 6386 0783
E: jopsj@dbsa.org

Will Megarry (Belfast, UK)
P: +44-2890-973448
E: w.megarry@qub.ac.uk

A world-first study on the Great Barrier Reef shows crown-of-thorns starfish have the ability to find their own way home—a behaviour previously undocumented—but only if their neighbourhood is stocked with their favourite food: corals.

Australian researchers observed the starfish emerging from their shelters in the afternoons so they could feed on coral during the night before returning home at dawn.

“The crown-of-thorns starfish often partied all night, slept-in and only those with a well-stocked larder found their way home—so it’s very much a teenager model of behaviour,” said lead author Dr Scott Ling from the Institute for Marine and Antarctic Studies at the University of Tasmania.

“Their preferred prey is Acropora corals,” said co-author Professor Morgan Pratchett from the ARC Centre of Excellence for Coral Reef Studies at James Cook University (CoralCoE at JCU). Acropora is an important coral species—for the past two million years they have been the building blocks of reefs across the world.

“When populations of Acropora dropped, the starfish didn’t return home,” Prof Pratchett said. “Their behaviour is directly linked to the local abundance of Acropora.”

The results of the study show healthy reefs with a high cover of these corals may encourage crown-of-thorns aggregations and outbreaks. The outbreaks cause extensive, widespread and sustained coral loss throughout the Indo-Pacific region.

Similar examples of predator infestations driving environmental devastation include sea urchins overgrazing on kelp forests and coral reef fishes munching through patches of seagrass.

The researchers used in-situ time-lapse photography to track the movements of 58 starfish in the northern and southern Great Barrier Reef during an outbreak in 2015. In the absence of their preferred Acropora coral prey, starfish were typically homeless and instead roamed up to 20 metres per day.

“Unlike sea urchins that can switch diet once they overgraze kelp forests, results of the time-lapse monitoring indicate that the starfish will consume available Acropora and ultimately eat themselves out of house and home before dispersing in search of new feeding grounds,” Dr Ling said.

Previous outbreaks on the Great Barrier Reef were recorded in 1962, 1979, 1993 and 2009. Though mass-coral bleaching due to global warming is now the greatest threat to coral reefs worldwide, the combined impact of mass-bleaching and crown-of-thorns outbreaks is potentially catastrophic for coral reefs.

“By better understanding the behaviour of these starfish we can help prevent and control their outbreaks, which will help alleviate the pressures on coral reefs,” Prof Pratchett said.


Ling S, Cowan Z, Boada J. Flukes B, Pratchett M. (2020). ‘Homing behaviour by destructive crown-of-thorns starfish is triggered by local availability of coral prey’. Proceedings of the Royal Society B. DOI: 10.1098/rspb.2020.1341


Photos and video are available for media use here. Please note these are for single use with this story only, not for any other story. Credit must be given to the content owner in the filename. No archival permissions are granted.


Prof Morgan Pratchett (AEST, Townsville)
P: +61 (0)488 112 295
E: morgan.pratchett@jcu.edu.au

Dr Scott Ling (AEDT, Hobart)
P: +61 (0)418376240
E: scott.ling@utas.edu.au


Melissa Lyne / CoralCoE at JCU (AEDT, Sydney)
P: +61 (0) 415 514 328
E: melissa.lyne@jcu.edu.au

An international team of scientists has found leaving more big fish in the sea reduces the amount of carbon dioxide (CO2) released into the Earth’s atmosphere.

When a fish dies in the ocean it sinks to the depths, sequestrating all the carbon it contains with it. This is a form of ‘blue carbon’ – carbon captured and stored by the world’s ocean and coastal ecosystems.

“But when a fish is caught, the carbon it contains is partly emitted into the atmosphere as COa few days or weeks after,” said Gaël Mariani, a PhD student at the University of Montpellier in France.

Mr Mariani led a world-first study showing how ocean fisheries have released at least 730 million metric tons of CO2 into the atmosphere since 1950. An estimated 20.4 million metric tons of CO2 was emitted in 2014—equivalent to the annual emissions of 4.5 million cars.

Co-author Professor David Mouillot from the ARC Centre of Excellence for Coral Reef Studies at James Cook University (CoralCoE at JCU) and the University of Montpellier said the carbon footprint of fisheries is 25 percent higher than previous industry estimates.

“Fishing boats produce greenhouse gases by consuming fuel,” Prof Mouillot said. “And now we know that extracting fish releases additional COthat would otherwise remain captive in the ocean.”

Large fish such as tuna, sharks, mackerel and swordfish are about 10 to 15 percent carbon.

“When these fish die, they sink rapidly,” Prof Mouillot said. “As a result, most of the carbon they contain is sequestered at the bottom of the sea for thousands or even millions of years. They are therefore carbon sinks—the size of which has never been estimated before.”

He says this natural phenomenon—a blue carbon pump—is increasingly and greatly disrupted by industrial fishing.

The authors also say the phenomenon has not only been overlooked until now, but it happens in areas where fishing is not economically profitable: in the Central Pacific, South Atlantic, and North Indian Oceans.

“Fishing boats sometimes go to very remote areas—with enormous fuel consumption—even though the fish caught in these areas are not profitable and fishing is only viable thanks to subsidies,” Mr Mariani said.

For the authors of the study, the new data strongly supports more reasoned fishing.

The annihilation of the blue carbon pump represented by large fish suggests new protection and management measures must be put in place, so that more large fish can remain a carbon sink and no longer become an additional CO2 source,” Mr Mariani said. “And in doing so we further reduce CO2 emissions by burning less fuel.”

“We need to fish better,” Prof Mouillot said.


Mariani G, Cheung W, Lyet A, Sala E, Mayorga J, Velez L, Gaines S, Dejean T, Troussellier M, Mouillot D. (2020). ‘Let more big fish sink: Fisheries prevent blue carbon sequestration—half in unprofitable areas’. Science Advances. DOI: 10.1126/sciadv.abb4848 


Photos are available for media use here. Please note these are for single use with this story only, not for any other story. Credit must be given to the photographer as stated in the image filename. No archival permissions are granted.


Gaël Mariani (France)
 +33 (0)6 80 91 75 93

Prof David Mouillot (France)
+33 (0)6 09 47 21 47


Melissa Lyne (Sydney, AEDT)
Media Manager, CoralCoE
 +61 (0)415 514 328
E: melissa.lyne@jcu.edu.au

Australian scientists have discovered a massive detached coral reef just off Cape York on the Great Barrier Reef that’s taller than the Empire State Building or the Sydney Tower.

The scientists found the reef, which is more than 500m high, as they were mapping the northern Great Barrier Reef seabed from aboard the Schmidt Ocean Institute’s research vessel Falkor.

“The base of the blade-like reef is 1.5km wide, then rises 500m to its shallowest depth of only 40m below the sea surface,” said Dr Tom Bridge, a Principal Investigator on the expedition who is based at the ARC Centre of Excellence for Coral Reef Studies at James Cook University (CoralCoE at JCU). Dr Bridge is also Senior Curator of Corals at the Queensland Museum.

It’s the first detached reef found in more than 120 years. “This newly discovered detached reef adds to the seven other tall detached reefs in the area—all otherwise mapped in the late 1800s,” Dr Bridge said.

The collection includes the reef at Raine Island, which is the world’s most important green sea turtle nesting area.

Expedition leader Dr Rob Beaman from JCU said he was surprised and elated with the discovery. The Schmidt Ocean Institute’s underwater robot SuBastian explored the new reef, which was videoed and live-streamed.

“To not only map the reef in 3D detail, but to also see this discovery with SuBastian is incredible,” Dr Beaman said.

The finding adds to a year of underwater discoveries by the Schmidt Ocean Institute.

The year started with the discovery of deep-sea coral gardens and graveyards in Bremer Canyon Marine Park. In April, scientists found the longest recorded sea creature—a 45m siphonophore in Ningaloo Canyon—plus up to 30 new species. Discoveries in August include five undescribed species of black coral and sponges as well as Australia’s first observation of rare scorpionfish in the Coral Sea and Great Barrier Reef Marine Parks.

Wendy Schmidt, co-founder of Schmidt Ocean Institute, said there are still many unknown structures and species within our oceans.

“The state of our knowledge about what’s in the ocean has long been so limited,” Ms Schmidt said.

“Thanks to new technologies that work as our eyes, ears and hands in the deep ocean, we have the capacity to explore like never before. New oceanscapes are opening to us, revealing the ecosystems and diverse life forms that share the planet with us.”

“We know more about the surface of the moon than we know about what lies in the depths beyond our coastlines,” Dr Bridge said.

“Combining mapping data and underwater imagery helps understand more about this newly discovered reef and its role within the Great Barrier Reef World Heritage Area.”

The Falkor is currently on a 12-month exploration of the ocean surrounding Australia. Scientists on the voyage will continue to probe and map the depths of the northern Great Barrier Reef until mid-November.


Media can access imagery here.


Dr Tom Bridge
P: 07 4726 0635
E: thomas.bridge@jcu.edu.au


Melissa Lyne/ Coral CoE at JCU
P: 0415 514 328
E: melissa.lyne@jcu.edu.au

Carlie Wiener/ Schmidt Ocean Institute
P: (808) 628-8666
E: cwiener@schmidtocean.org

A new study of the Great Barrier Reef shows populations of its small, medium and large corals have all declined in the past three decades.

Lead author Dr Andy Dietzel, from the ARC Centre of Excellence for Coral Reef Studies (CoralCoE), says while there are numerous studies over centuries on the changes in the structure of populations of humans—or, in the natural world, trees—there still isn’t the equivalent information on the changes in coral populations.

“We measured changes in colony sizes because population studies are important for understanding demography and the corals’ capacity to breed,” Dr Dietzel said.

He and his co-authors assessed coral communities and their colony size along the length of the Great Barrier Reef between 1995 and 2017. Their results show a depletion of coral populations.

“We found the number of small, medium and large corals on the Great Barrier Reef has declined by more than 50 percent since the 1990s,” said co-author Professor Terry Hughes, also from CoralCoE.

“The decline occurred in both shallow and deeper water, and across virtually all species—but especially in branching and table-shaped corals. These were the worst affected by record-breaking temperatures that triggered mass bleaching in 2016 and 2017,” Prof Hughes said.

The branching and table-shaped corals provide the structures important for reef inhabitants such as fish. The loss of these corals means a loss of habitat, which in turn diminishes fish abundance and the productivity of coral reef fisheries.

Dr Dietzel says one of the major implications of coral size is its effect on survival and breeding.

“A vibrant coral population has millions of small, baby corals, as well as many large ones— the big mamas who produce most of the larvae,” he said.

“Our results show the ability of the Great Barrier Reef to recover—its resilience—is compromised compared to the past, because there are fewer babies, and fewer large breeding adults.”

The authors of the study say better data on the demographic trends of corals is urgently needed.

“If we want to understand how coral populations are changing and whether or not they can recover between disturbances, we need more detailed demographic data: on recruitment, on reproduction and on colony size structure,” Dr Dietzel said.

“We used to think the Great Barrier Reef is protected by its sheer size—but our results show that even the world’s largest and relatively well-protected reef system is increasingly compromised and in decline,” Prof Hughes said.

Climate change is driving an increase in the frequency of reef disturbances such as marine heatwaves. The study records steeper deteriorations of coral colonies in the Northern and Central Great Barrier Reef after the mass coral bleaching events in 2016 and 2017. And the southern part of the reef was also exposed to record-breaking temperatures in early 2020.

“There is no time to lose—we must sharply decrease greenhouse gas emissions ASAP,” the authors conclude.


Dietzel A, Bode M, Connolly S, Hughes T. (2020). ‘Long-term shifts in the colony size structure of coral populations along the Great Barrier Reef’. Proceedings of the Royal Society B. DOI: 10.1098/rspb.2020.1432


Photos are available for media use here. Please note these are for single use with this story only, not for any other story. Credit must be given to Andreas Dietzel. No archival permissions are granted.


Dr Andreas Dietzel (Townsville, AEST)
P: +61 (0)432 916 224

Prof Terry Hughes (Townsville, AEST)
+61 (0)400 720 164


Melissa Lyne (Sydney, AEDT)
Media Manager, Coral CoE
+61 (0)415 514 328
E: melissa.lyne@jcu.edu.au

Scientists have found that as the world undergoes profound environmental change, identifying and protecting ‘novel’ communities of species can help prevent extinctions within vulnerable ecosystems.

Professor John Pandolfi and Dr Timothy Staples from the ARC Centre of Excellence for Coral Reef Studies at The University of Queensland (CoralCoE at UQ) are the lead authors of a new study in Science that looked at how combinations of plankton species changed across the world’s marine ecosystems in the past 66 million years. From this, their team developed a world first method to detect ‘novel’ communities of species across all ecosystems.

“A novel ecological community is one with combinations of species that are different to any past observations from that site,” Prof Pandolfi said. “These different species combinations can be due to new species arriving in the community, existing species leaving, or species becoming rarer or more common.”

“We found that when novel communities formed, existing species were twice as likely to disappear from the community permanently, representing a ‘local’ extinction.”

“Species in the novel community were also more likely to be new arrivals that had never been observed in the community before.”

An example of a modern novel community is the coral reefs of the Caribbean, where the two once dominant species of branching coral are now rare. Those reefs are now home to new, or novel, communities of corals. The loss of the branching corals is due to the impacts of overfishing, changes in water quality, and climate change—resulting in new configurations of coral species within the Caribbean reef communities. And the shift means the benefits of the reef are now different: different species means different inhabitants and functions.

“The challenge is to manage at risk or vulnerable areas like this where novel communities exist, or where they’re in the process of forming,” Prof Pandolfi said.

“To do this we need to understand the changes in species composition we see in novel communities, as well as what is driving these changes. To achieve these goals, we need to be able to reliably identify when a novel community has emerged.”

The study outlines the first standardised, quantitative methodology for determining the existence of novel ecological communities. The researchers used a database of marine plankton over millions of years, but the methodology was designed to be applied more generally.

“We came up with a measure of novelty that can be used with community data from any time scale, organism or ecosystem, so comparative approaches to the study of novelty are now possible,” Dr Staples said. “In this study, we applied our methodology to the past 66 million years, but it would work just as well on much shorter time frames.”

The researchers examined the marine plankton record using a global set of microfossil data from deep sea drilling cores— the NSB marine microfossil database, created and run by the Museum für Naturkunde in Berlin. By incorporating updated taxonomy and age models they built community data for species across geological time.

Prof Pandolfi said while novelty was rare, extinction was an important component. And after novel communities emerged, subsequent communities were more likely to develop into yet other novel states.

“Novelty begets novelty,” Prof Pandolfi said. “And the likelihood of extinction was higher when novel communities emerged.”

He said the pressures that cause communities to become novel in the first place need to be relieved. “Otherwise we may end up with cascading novelty, where the emergence of novel communities drives further novelty, including the loss of existing, native, species.”

Prof Pandolfi says this means when a novel community is identified it needs attention and effective preventive management. He also says future studies need to identify novel communities within vulnerable ecosystems, such as the Great Barrier Reef. “At the end of the day that’s where we want to go to test this,” he said.

Though the time frame of evolutionary change is generally much slower than the timeframe of change currently occurring on the Great Barrier Reef, there are signs that novelty communities may be emerging there. The assemblage of corals on the reef are not what they were five or ten years ago.

“Our novelty framework is equally applicable to investigate the Great Barrier Reef at this ecological scale,” Dr Staples said.

“Modern novel ecological communities may need to be managed effectively to prevent the propagation of subsequent novel communities, because of the associated risk of increased extinction,” Prof Pandolfi said.

“We can’t just throw in the towel and let those ecosystems degrade, we need to arrest this progression.”


Pandolfi J, Staples T, Kiessling W. (2020). ‘Increased extinction in the emergence of novel ecological communities’. Science. DOI: 10.1126/science.abb3996


Photos are available for media use here. Please note these are for single use with this story only, not for any other story. Credit must be given to the photographer as in the file name. No archival permissions are granted.


Prof John Pandolfi (Australia, AEST)
P: +61 (0)400 982 301
E: j.pandolfi@uq.edu.au

Dr Timothy Staples (Australia, AEST)
P: +61 (0) 412 506 078
E: timothy.staples@uqconnect.edu.au


Melissa Lyne (Australia, AEST)
Media Manager, Coral CoE
P: +61 (0)415 514 328
E: melissa.lyne@jcu.edu.au


Scientists say a ‘portfolio’ of protected areas within marine parks such as the Great Barrier Reef can help secure sustainable fish populations.

Dr Hugo Harrison from the ARC Centre of Excellence for Coral Reef Studies at James Cook University (Coral CoE at JCU) led a study on the effects of marine reserves, or no-take zones, on fish populations.

“The Great Barrier Reef Marine Park has established networks of no-take zones,” Dr Harrison said. “A ‘portfolio’ of these protected areas can help connect reefs and ultimately provide more reliable quantities of fish across an ecosystem.”

Dr Harrison says no-take zones—areas closed to fishing—on their own act as valuable sources of fish for neighbouring reefs. These areas support more fish, which then produce even greater numbers of baby fish. But, just how many babies survive and where they end up varies greatly from year to year. These fluctuations can be volatile and uncertain.

“Our findings are comparable to investing your resources wisely,” said Professor Michael Bode, a co-author on the study from the Queensland University of Technology. “If you put all your money into one type of stock and then the value of that entire industry crashes, then all of your investment will crash too.”

“By investing in a variety of stocks you can buffer or dampen market volatility and still maintain a valuable portfolio. Our study proves that marine protected areas are like financial stocks: if you invest in multiple smaller reserves instead of putting all your effort into one large reserve, you ensure a stable supply of fish to both recreational and commercial fishers.”

The authors tracked more than 1,500 baby fish using DNA ‘fingerprinting’ techniques. The baby fish were traced back to their parents inside a network of four reserves.

The researchers found that each reserve was an important but variable source of baby fish. However, together, the network of reserves generated a reliable source of offspring to replenish exploited fish stocks in surrounding reefs.

The study coincides with two significant international reports illustrating the stark decline of the natural world: the Living Planet Report 2020 and the Global Biodiversity Outlook 5.

“Governments all around the world failed to meet any of the UN Sustainable Development Goals on Biodiversity Conservation,” Dr Harrison said. “To stem the loss of natural habitats, they had committed in 2010 to expand the world’s nature reserves across ten percent of coastal and marine areas by 2020.”

“Though protected ocean areas have tripled in these past ten years, the targets remain well below the recommendation of at least 30 percent protection recommended by the International Union for Conservation of Nature (IUCN).”

The IUCN also recently released guidelines on protecting connectivity and ‘corridors’ within ecosystems, which are essential for healthy natural habitats—for conservation and for climate change adaptation.

Prof Bode says maintaining corridors between protected areas is easy to picture in a terrestrial realm—for example, in a forest setting where animals can move freely between areas.

“But it’s a lot harder in the marine realm, where connectivity pathways between habitats are difficult to predict,” Prof Bode said. “We can’t maintain ‘corridors’ in coral reef seascapes, so we need other mechanisms to ensure connectivity through these ‘portfolios’, as we do on the Great Barrier Reef.”

Dr Harrison said there is an urgent need for further discussions on the value of marine reserve networks—both locally and internationally.

“Our research is a timely reminder of the value of marine networks in protecting not only biodiversity but industries including tourism and the millions of people globally whose livelihoods depend on healthy ecosystems.”


Harrison H, Bode M, Williamson D, Berumen M, Jones G. (2020). ‘A connectivity portfolio effect stabilizes marine reserve performance’. Proceedings of the National Academy of Sciences of the United States of America. DOI: 10.1073/pnas.1920580117


Photos are available for media use here. Please note these are for single use with this story only, not for any other story. Credit must be given to the photographer as stated in the image credit file. No archival permissions are granted.


Dr Hugo Harrison (Townsville, Australia)
P: +61 (0) 499 523 939
E: hugo.harrison@jcu.edu.au

Prof Michael Bode (Brisbane, Australia)
P: +61 (0) 414 108 439
E: michael.bode@qut.edu.au

Melissa Lyne/ Coral CoE at JCU
P: +61 (0) 415 514 328
E: melissa.lyne@jcu.edu.au

Scientists have developed a new genetic tool that can help them better understand and ultimately work to save coral reefs.

“Surprisingly, we still don’t know how many coral species live on the Great Barrier Reef, how to identify them, or which species live where. And those are the first steps in saving an ecosystem like that,” said Dr Peter Cowman from the ARC Centre of Excellence for Coral Reef Studies at James Cook University (Coral CoE at JCU).

Dr Cowman led an international study on coral classification. Classification explains how species are related to each other. Shared similarities and differences provide a key to help identify species. For example, dogs and cats are classified on different branches of the evolutionary tree using their body design.

A seemingly finer detail, like how cats can retract their claws and dogs cannot, helps people decide whether a newly discovered species of small carnivore is more like a dog or a cat.

Dr Cowman said an important challenge when identifying corals is that the same species can grow in many different ways.

“For instance, some species can grow with either a plate or branch structure. The study found classifying corals by their physical characteristics didn’t match the classifications based on their genetics,” he said.

Species identification underpins almost all biological and ecological research, and the new study challenges more than 200 years of coral classification. The researchers say the ‘traditional’ method does not accurately capture the differences between species or their evolutionary relationships.

Co-author Professor Andrew Baird, also from Coral CoE at JCU, led a recent scientific journey along the Great Barrier Reef, uncovering ‘treasure troves’ of new, unidentified coral species.

“The traditional classification of corals is dead,” Prof Baird said.

“But these new molecular tools allow us to reinvent a new classification system on the ashes of the old. Hence, the name we have given to the research: Project Phoenix,” he said.

“These are exciting times to be a coral taxonomist.”

“We need to review the way we currently identify corals,” said co-author Dr Tom Bridge from Coral CoE at JCU, who is also the curator of corals at the Queensland Museum.

Dr Bridge said research in the past ten to 20 years has already revolutionised the understanding of the older branches on the evolutionary tree of corals. But, to date, there has been little progress on the more recent twigs of the ‘tree’—the living species—particularly with the most diverse and ecologically-important group: the Acropora.

“The Acropora are the branching ‘staghorn’ corals that dominate reefs,” Dr Bridge said. “Yet, even in well-researched locations like the Great Barrier Reef, we can’t identify many of these species accurately.”

Dr Cowman said the traditional method doesn’t reflect the tens of millions of years of coral evolution.

“At the moment, we’re flying blind,” he said.

Dr Andrea Quattrini, curator of corals at the Smithsonian Institution’s National Museum of Natural History, developed the new genetic tool. She said it provides a way forward with plans to secure the future of coral reefs.

“By comparing thousands of key genetic coral features, we were able to discern the evolutionary relationships of corals from the Great Barrier Reef and broader Indo-Pacific region,” Dr Quattrini said.

“The result is a new classification that provides important scientific knowledge to assess the various intervention strategies currently being proposed on the Great Barrier Reef and elsewhere.”

Some of the interventions being proposed on the reef include hybridising species and moving some populations south.

“It’s clear we do not know enough about many of the species we’re dealing with. This new method can help generate the robust science we need to assess such proposals,” Dr Bridge said.


Cowman P, Quattrini A, Bridge T, Watkins-Colwell G, Fadli N, Grinblat M, Roberts E, McFadden C, Miller D, Baird A. (2020). ‘An enhanced target-enrichment bait set for Hexacorallia provides phylogenomic resolution of the staghorn corals (Acroporidae) and close relatives’. Molecular Phylogenetics and Evolution. DOI: 10.1016/j.ympev.2020.106944


Photos are available for media use here. Please note these are for single use with this story only, not for any other story. Credit must be given to Tom Bridge. No archival permissions are granted. The whole or part of all images remain the property of the photographer and cannot be used, copied or disseminated in any way without prior written permission of the photographer other than for the purposes outlined above.


Dr Peter Cowman
P: 07 4781 3194
E: peter.cowman@jcu.edu.au

Dr Tom Bridge
P: 07 4726 0635
E: thomas.bridge@jcu.edu.au

Prof Andrew Baird
P: 0400 289 770
E: andrew.baird@jcu.edu.au


Melissa Lyne/ Coral CoE at JCU
P: 0415 514 328
E: melissa.lyne@jcu.edu.au

A new study suggests ‘dead’ coral rubble can still sustain life, with a large number of tiny animals hidden and living amongst the ruins.

While the study does not suggest dead coral has the same or higher function as a live coral reef, it suggests reef rubble habitat is not as desolate, unattractive and ‘dead’ as is commonly assumed.

“When people think of coral reefs, they often think of larger invertebrates that are easily found, such as sea cucumbers, starfish and giant clams,” said lead author Dr Kenny Wolfe from the ARC Centre of Excellence for Coral Reef Studies at The University of Queensland.

“But interestingly, dead coral rubble supports more of what we call ‘cryptic’ animals.”

Cryptic animals are ‘hidden’ creatures, including tiny crabs, fishes, snails and worms—all of which hide in the nooks and crannies of the reef to avoid predation.

“And just like on land with small insects and bugs, biodiversity in the sea can be dominated by these tiny invertebrates,” Dr Wolfe said.

As these creatures try to remain hidden, finding and surveying them requires particular care and attention.

Dr Wolfe teamed up with UQ Innovate to design 3D-printed coral stacks called RUBS (RUbble Biodiversity Samplers), to survey cryptic animals on coral reefs.

The 3D-printed ‘coral’ mimics the surrounding reef rubble, seamlessly inviting hidden reef organisms to be unknowingly monitored.

“Every piece of coral or rubble is different,” Dr Wolfe said.

RUBS provide a uniform method to survey the hidden majority on coral reefs. By sampling the RUBS’ structures over time, the team were able to identify changes in the cryptic population, adding pieces to the puzzle and filling in the unknowns of coral reef food webs.

“This data fills important knowledge gaps, such as how small cryptic animals support coral reefs from the bottom of the food chain, all the way up to bigger predators,” Dr Wolfe said.

He believes the new technique is another step in better understanding our precious reefs—whether ‘alive’ or ‘dead’.

“These are important habitats, which support coral reef biodiversity and important food webs,” Dr Wolfe said.

“This new technology is a new opportunity for reef management, particularly for reef education and awareness. We’re excited to learn about and celebrate the diversity of life in this misunderstood habitat.”


Wolfe K, Mumby P. (2020). ‘RUbble Biodiversity Samplers: 3D‐printed coral models to standardize biodiversity censuses’. Methods in Ecology and Evolution. DOI: 10.1111/2041-210X.13462


Dr Kenny Wolfe
P: 0424 184 483
E: k.wolfe@uq.edu.au

A new study on coral evolution has found climates similar to what we’re seeing today have previously devastated hard-bodied corals—the architects of coral reefs—while making way for their softer-bodied relatives.

The study traced the evolution of corals over the past 770 million years and found warmer and more acidic waters had a dramatic effect on the diversity of corals and sea anemones.

Hard or ‘stony’ corals that are the engineers of modern tropical reefs could only proliferate when ocean conditions allowed them to construct their stony skeletons. When conditions did not favour these reef building species, other diverse softer corals and sea anemones flourished.

The international team leading the research includes biologists from Harvey Mudd College, American Museum of Natural History, the Smithsonian’s National Museum of Natural History, and the ARC Centre of Excellence for Coral Reef Studies at James Cook University (Coral CoE at JCU).

Co-author Dr Peter Cowman, from Coral CoE at JCU, says the findings are consistent with observations from today’s reefs, which are threatened by climate change and other human activities.

“Human carbon emissions are already devastating coral reefs today,” he said.

The rising levels of carbon dioxide in the atmosphere are warming and acidifying the waters, making them less hospitable for the hard corals and other organisms with shells and skeletons.

In the past, the soft-bodied species fared best after reef crises—at times when up to 90 percent of reef-building organisms died off as the oceans warmed and became more acidic.

However, though these softer-bodied species may be able to better adapt to climate change than stony corals, they don’t form large reefs.

The composition of corals on reefs has already undergone marked change—the Great Barrier Reef is not what it was 30, 10 or even five years ago.

“What we’re seeing now are changes in coral communities on reefs in response to the immediate threats of climate changes, like warmer waters,” Dr Cowman said. “On evolutionary timescales, changing ocean chemistry may make it more difficult for hard corals to grow, leading to more fundamental shifts in reef species.”

The new genetic analyses show that corals and sea anemones have been on the planet for 770 million years—250 million years before the earliest undisputed fossil evidence of their existence. In this time, they experienced massive shifts in climate, fluctuations in ocean chemistry and several mass extinctions.

The team examined how past conditions affected coral and sea anemone diversity, using a new molecular approach. They compared nearly 2,000 key regions of genomes to discern the evolutionary relationships between species.

The team analysed hundreds of specimens from around the world that are now stored in museum collections. When the molecular data was aligned with fossil evidence, it revealed how these diverse animals evolved over deep time.

Losing hard, reef-building corals has devastating impacts on the communities who depend on coral reefs and the rich, complex ecosystems they support for fishing, shoreline protection and tourism.

Lead author of the study, Dr Andrea Quattrini, research zoologist and curator of corals at the National Museum of Natural History, said corals suffered extinctions in the past when the climate posed challenges.

“We’ll likely see that in the future,” Dr Quattrini said. “The best way to protect them is to curb our carbon emissions.”

Co-author Dr Estefanía Rodríguez, a curator at the American Museum of Natural History, said the study shows how nature—through evolution—is able to adapt, survive and reinvent itself.

“The question is whether we will be able to adapt and reinvent ourselves once nature, as we currently know it, is not there anymore,” Dr Rodríguez said.


Quattrini A, Rodríguez E, Faircloth B, Cowman P, Brugler M, Farfan G, Hellberg M, Kitahara M, Morrison C, Paz- García D, Reimer J, McFadden C. (2020). ‘Paleoclimate ocean conditions shaped the evolution of corals and their skeletons through deep time’. Nature Ecology & Evolution. DOI: 10.1038/s41559-020-01291-1


Multimedia, including photos of living corals and their relatives, can be found via Dropbox here. (Password: coral).


Dr Peter Cowman (Australia, AEST)
P: 0490 231 223
E: peter.cowman@jcu.edu.au


Melissa Lyne (Australia, AEST)
Media Manager, Coral CoE at JCU
P: 0415 514 328
E: melissa.lyne@jcu.edu.au

Researchers have discovered a new way to measure the complexity of the world’s habitats—a crucial factor as environments across the globe face extraordinary change.

The study was led by Damaris Torres-Pulliza, a PhD candidate at the University of Hawai`i at the Hawai‘i Institute of Marine Biology (HIMB). Ms Torres-Pulliza and a team of ecologists and engineers, including from the ARC Centre of Excellence for Coral Reef Studies at James Cook University (Coral CoE at JCU), developed a relatively simple way to standardise how habitat complexity is measured.

The researchers say habitats range from the abyssal trenches to the tops of mountains, from coral reefs to tundra. These can be relatively simple, flat surfaces to highly complex three-dimensional structures—a concrete driveway to an old brick-pile in the backyard, respectively.

The researchers studied the coral reefs encircling Lizard Island, on the Great Barrier Reef, using a mix of robots and underwater cameras to measure their three-dimensional structure.

Associate Professor Mia Hoogenboom from Coral CoE at JCU said places with lots of nooks and crannies contain lots of living things.

“We spent many hours underwater counting and identifying nearly 10,000 corals found on the 3D maps,” said Dr Hoogenboom.

“The new method we developed can be used in both marine and terrestrial environments, allowing us to understand how complexity and biodiversity are related to each other in all kinds of habitats,” she said.

Dr Hoogenboom says complex habitats tend to contain more biodiversity, both in terms of more individuals and more species. This relationship is important, because it highlights a relatively simple mechanism by which to manipulate biodiversity. If habitat complexity decreases, one would expect biodiversity to decrease.

Dr Joshua Madin, an associate researcher at HIMB, says habitats are characterised by three factors: rugosity, fractal dimension and height range.

“If you think of your backyard brick-pile, rugosity tells you the amount of surface area there is for critters to live on; fractal dimension tells how many critters of different sizes can fit in among the bricks, and; height range sets an upper limit to critter size,” Dr Madin said. “You won’t find an elephant in your bricks, right?”

The analysis suggests only two of the three measurements are needed to characterise the structure of a habitat. This means ecologists can pick the two aspects of complexity that are easiest to measure and will automatically know the third—similar to calculating the third angle of a triangle if two angles are already known.

The theoretical breakthrough means scientists can back-calculate a richer picture of habitat complexity from previous studies and compare habitat complexity among different ecosystems.

“We found that using the three metrics together dramatically improves our ability to predict the distribution of biodiversity. This helps us understand how the structure of a place affects who lives there,” said Dr Maria Dornelas of the University of St Andrews.

Though the work is new and currently only applied to coral reefs, the researchers hope that their new theory might become the backbone of research into the relationships between habitat complexity and biodiversity in all ecosystems, both underwater and on land.


Torres-Pulliza D, Dornelas M, Pizarro O, Bewley M, Blowes S, Boutros N, Brambilla V, Chase T, Frank G, Friedman A, Hoogenboom M, Williams S, Zawada K, Madin J. (2020) ‘A geometric basis for surface habitat complexity and biodiversity’. Nature Ecology and Evolution. DOI: 10.1038/s41559-020-1281-8


Photos are available for media use here. Please note these are for single use with this story only, not for any other story. The photos must be credited to Damaris Torres-Pulliza. No archival permissions are granted.

Melissa Lyne (Australia, AEST)
Media Manager, Coral CoE at JCU
P: +61 (0)415 514 328
E: melissa.lyne@jcu.edu.au

A new study shows nutrients can aggravate the already negative effects of climate change on corals to trigger mass coral bleaching.

Coral reef environments are typically low in naturally occurring nutrients such as nitrogen and phosphorous compounds. But ocean currents passing by can bring in a concentration of nutrients from elsewhere. Similarly, nutrients from man-made fertilisers and stormwater runoff enter reefs from adjacent coastlines.

Lead author Dr Thomas DeCarlo from the King Abdullah University of Science and Technology (KAUST) says corals are sensitive to high levels of nutrients.

“As the climate warms, mass coral bleaching could occur as often as annually within this century,” Dr DeCarlo said. “In our study, we found that already heat-stressed corals exposed to excess nutrient levels were even more susceptible to bleaching.”

The study suggests ecosystem managers can reduce the impacts of coral bleaching by implementing strategies to reduce nutrient stress in areas subject to thermal stress.

Co-author Professor John Pandolfi from the ARC Centre of Excellence for Coral Reef Studies (Coral CoE) at The University of Queensland says this and previous studies, including on the Great Barrier Reef, related coral bleaching to combinations of heat and nutrient stresses.

“Our results provide a roadmap for coral reef conservation efforts to be at their most effective,” Prof Pandolfi said. “We suggest oceanographic processes should be included when deciding when and where to allocate resources or protection.”

Using the skeletal cores of long-living corals, the authors studied the past few decades worth of bleaching events in the Red Sea. They found the reefs historically suffered severe bleaching only when high sea surface temperatures were coupled with high nutrient levels.

The Red Sea was chosen as a study site as it is one of the only marine environments where the effects of summertime nutrients and heat stress are independent of each other: only one area has a single major source of nutrients in the summer, when a water mass brings nutrients to the surface through a process called upwelling.

Previous field tests on the role of nutrients in coral bleaching were otherwise difficult: nutrients and temperature often co-vary in the ocean, making it difficult to disentangle their effects. Nutrient loads are also difficult to measure in the same way sea surface temperatures are, via satellite.

“The fact that nutrients are more difficult to measure than temperature may be restricting our recognition of their importance,” Dr DeCarlo said. “And we need greater longer-term monitoring efforts of nutrient levels on coral reefs.”

“Incorporating nutrient-supplying ocean currents into coral bleaching forecasts will enhance those predictions that are based on temperatures alone,” Prof Pandolfi said.

“Our research suggests that projections of coral reef futures should move beyond solely temperature-based stress to incorporate the influence of ocean current systems on coral reef nutrient enrichment, and thus susceptibility to bleaching,” Dr DeCarlo said.


DeCarlo T, Gajdzik L, Ellis J, Coker D, Roberts M, Hammerman N, Pandolfi J, Monroe A, Berumen M. (2020). Science Advances. ‘Nutrient-supplying ocean currents modulate coral bleaching susceptibility’. DOI: 10.1126/sciadv.abc5493


A photo is available for media use here. Please note this is for single use with this story only, not for any other story. It must be credited to Jess Bouwmeester. No archival permissions are granted.


Dr Thomas DeCarlo (Hawaii/USA, HST)
P: +1 808 221 8584
E: thomas.decarlo@kaust.edu.sa

Prof John Pandolfi (Australia, AEST)
P: +61 (0)400 982 301
E: j.pandolfi@uq.edu.au


Melissa Lyne (Australia, AEST)
Media Manager, Coral CoE
P: +61 (0)415 514 328
E: melissa.lyne@jcu.edu.au

A world-first study examining the scales of management of the Great Barrier Reef has the potential to help sustain other ecosystems across the world.

Massive marine ecosystems like the Great Barrier Reef aren’t just a vibrant home to fish, corals and other creatures, they are also an important source of people’s food, livelihoods and recreation.

The new study suggests the way people are managed when undertaking various activities within the marine park—like fishing, boating, and scientific research—could serve as an exemplary model for sustainably managing other ecosystems that humans use.

“There is plenty of evidence to suggest that the Great Barrier Reef is managed at appropriate scales within its boundaries,” said lead author Professor Graeme Cumming, incoming Director of the ARC Centre of Excellence for Coral Reef Studies.

The reef served as a case study for mapping and measuring different scale matches between people and ecosystems. Prof Cumming explains the concept of scale matches using a backyard garden as an example of an ecosystem.

“For a house with a garden, you already have permission to manage that garden—to mow the lawn and trim the trees inside your fences. To look after all the parts of it. That’s a scale match,” Prof Cumming said.

He says being able to manage only a flower bed within the garden is a small-scale match. “If you only have permission to manage the flower bed in your garden, you can manage the flowers, but your lawn and trees become unkempt. The weeds and pests affecting the flowers may come from an adjacent part of the garden, which you’d then have no control over,” he said.

The Great Barrier Reef Marine Park Authority (GBRMPA) manages the entire marine park. Some permits, such as permission to access areas by boat as part of a commercial operation, may cover most of the park.

GBRMPA also manages smaller scale permits within the marine park boundaries—small-scale matches that work best for activities like commercial tourism, lobster fisheries or the installation of certain structures like jetties or moorings.

The study found the permits issued for human activities generally occurred at larger scales than the particular individual marine features of interest, such as reefs or islands.

“The finding that people are managed at a broader scale than ecological variation suggests a general principle for permitting and management,” Prof Cumming said. “In essence, people like to have choices about where they go and how they respond to change. This means that they prefer to operate at a broader spatial scale than the ecological features they are interested in, rather than the same scale.”

The findings suggest this approach to managing people at broader rather than finer scales may be more effective. For small protected areas, increasing the size of the permissible area may even be critical.

However, GBRMPA can’t manage the ecosystem’s biggest impact, which lies outside park boundaries: climate change.

“Broad scale problems, like climate change, can only be managed with broad scale solutions, like global action,” Prof Cumming said. “This is a scale mismatch because these impacts come from well outside the marine park boundaries.”

GBRMPA also don’t have control over what happens on the land directly adjacent to the reef. Not being able to stop pollutants and pesticides in storm water reaching the reef is another scale mismatch.

Prof Cumming says comparing the results of this study to similar data from other marine parks, including those that are recognised as dysfunctional, will help determine if the management of the Great Barrier Reef Marine Park is unusual or typical.

“This study does not offer a direct solution for management,” Prof Cumming said. “But it provides a new approach that extends our toolbox for diagnosing social-ecological scale mismatches and responding to them.”


Cumming S, Dobbs K. (2020). ‘Quantifying social-ecological scale mismatches suggests people should be managed at broader scales than ecosystems’. One Earth. DOI: 10.1016/j.oneear.2020.07.007


Professor Graeme Cumming
E: graeme.cumming@jcu.edu.au

Melissa Lyne
Media Manager, Coral CoE
P: +61 (0) 415 514 328
E: melissa.lyne@jcu.edu.au

Connections with friends and family are key to helping communities adapt to the devastating impact of climate change on their homes and livelihoods, a new study shows.

The research found people are more empowered to respond when they see others doing the same.

Scientists analysed how an island community in Papua New Guinea of around 700 people coped with the impact of encroaching sea-levels and dwindling fish stocks. The study, published in the journal Nature Climate Change, examined the actions households took to deal with these impacts.

Lead author Dr Michele Barnes, from the ARC Centre of Excellence for Coral Reef Studies at James Cook University (Coral CoE at JCU), said: “We found their actions were related to their social networks, the ways they are connected to other people within the community.”

“To cope with the impacts of climate change, existing practices or behaviours can be tweaked—this is adaptation. However, in some cases this won’t be enough, and people need to enact more fundamental changes—transformation.”

“In our case, adaptation included things like building sea walls to protect existing land use,” said co-author Dr Jacqueline Lau, from Coral CoE and WorldFish. “And transformation involved developing alternative food and income sources away from fish and fishing-related activities.”

Essentially both sets of actions are necessary to combat the impacts of climate change.

Dr Barnes says influence within social networks is what encouraged both sets of actions. The team found the households more socially connected to others taking action were more likely to do the same.

“It may be a situation of ‘like-attracts-like’ where households with particular mindsets are more socially connected to similar households,” Dr Barnes said. “Another explanation is that households were influencing each other’s actions. It’s likely a combination of the two,” she said.

The authors also found household connections with the marine environment played an important role in determining the responses to climate impacts.

“Climate change and other human impacts rapidly degrade coral reef ecosystems and alter the composition of reef fish communities,” said co-author Professor Nick Graham, of Lancaster University in the UK.

“The adaptation of coastal communities is becoming essential. Our research highlights that interacting with and learning from the marine environment is one mechanism through which this adaptation can be achieved,” he said.

Dr Barnes says the policies and programs seeking to reduce vulnerability to climate change often focus on building up material assets or creating infrastructure.

“Our research emphasises a broader set of factors can play an important part in the actions communities end up taking,” she said.

Barnes M, Wang P, Cinner J, Graham N, Guerrero A, Jasny L, Lau J, Sutcliffe S, Zamborain-Mason J. (2020). ‘Social determinants of adaptive and transformative responses to climate change’. Nature Climate Change. DOI: 10.1038/s41558-020-0871-4

Photos are available for media use here. Please note these are for single use with this story only, not for any other story. They must be credited to the photographer. No archival permissions are granted.


Dr Michele Barnes (Australia, AEST)
P: +61 (0)408 677 570
E: michele.barnes@jcu.edu.au

Dr Jacqueline Lau (Australia, AEST)
P: +61 (0)403 990 738
E: jacqueline.lau@jcu.edu.au

Prof Nick Graham (London, BST)
P: +44 (0)7479 438914
E: nick.graham@lancaster.ac.uk


Melissa Lyne (Australia, AEST)
Media Manager, Coral CoE at JCU
P: +61 (0)415 514 328
E: melissa.lyne@jcu.edu.au


Australian Research Council Pandora

Partner Research Institutions

Partner Partner Partner Partner
Coral Reef Studies

ARC Centre of Excellence for Coral Reef Studies
James Cook University Townsville
Queensland 4811 Australia

Phone: 61 7 4781 4000
Email: info@coralcoe.org.au