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

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A world first study within the Great Barrier Reef Marine Park has found limited fishing zones (yellow zones) are still important conservation and fisheries management tools when paired with no-fishing zones.

Lead author Dr April Hall, from the ARC Centre of Excellence for Coral Reef Studies at James Cook University (Coral CoE at JCU), said partially protected yellow zones still contain healthy numbers of reef fish targeted for recreational and commercial fishing. These include coral trout, tropical snappers, emperors and tuskfish.

Yellow zones limit, rather than prohibit, fishing through fishing gear restrictions. For example, limited line fishing is allowed with one rod or line and one hook per person.

“We found the numbers of popular fishing targets in these yellow zones are up to 69 percent of what they are in the adjacent no-take green zones,” Dr Hall said.

Green zones, where all fishing is prohibited, are more frequently studied areas. Their benefits to conservation and flow-on fisheries are already well-established.

Though there were fewer fishing targets in the yellow zones, both yellow and green zones had similar abundances of non-target fishes and richness of fish species overall.

“Both green and yellow zones supported a great diversity of fish species,” Dr Hall said.

Yellow zones were set aside as partially protected areas in the Great Barrier Reef Marine Park Authority’s (GBRMPA) 2004 zoning plan. Co-author Darren Cameron, from GBRMPA, said the Great Barrier Reef is one of the world’s largest and most comprehensively studied marine parks. However, this research is the first to specifically address yellow zones.

“We found yellow zones, in conjunction with green zones, are an effective management tool. They contribute to marine park conservation goals whilst positively supporting fishing opportunities,” Mr Cameron said.

The study took place within the Hinchinbrook and Dunk Island region. The area has outstanding biodiversity and cultural heritage. It is an important area for recreational, commercial and indigenous fishing. The study also considers zoning on inshore reefs, an area which has previously received little attention.

The project is a collaboration between Coral CoE at JCU and GBRMPA, as part of Dr Hall’s Advance Queensland Post-Doctoral Fellowship. The analyses form part of her broader project evaluating yellow zones across the Great Barrier Reef.

“Data from our project will be critical for conservation and fisheries alike,” Dr Hall said.


Hall A, Cameron D, Kingsford M. 2021. ‘Partially protected areas as a management tool on inshore reefs’. Rev Fish Biol Fisheries. DOI: 10.1007/s11160-021-09654-y


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


April Hall (Coral CoE at JCU, Townsville, Australia)
P: +61 (0) 458 565 194
E: april.hall@jcu.edu.au

Darren Cameron (GBRMPA, Townsville, Australia)
P: +61 (0) 438375569
E: Darren.Cameron@gbrmpa.gov.au


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


What is a Yellow Zone?

Fishing activities allowed in a Conservation Park (Yellow) Zone include:

For a description of the full range of Great Barrier Reef Marine Park zones and their restrictions, see here.

Today, the British Ecological Society announced Dr Renato Morais from the ARC Centre of Excellence for Coral Reef Studies at James Cook University as the winner of this year’s Haldane Prize.

The prize is given each year to the best paper in the journal Functional Ecology from an early career author. Dr Morais was awarded the prize for: Severe coral loss shifts energetic dynamics on a coral reef.

Dr Morais led an international team of researchers comparing reef survey data from 2003–2004 and 2018 at Lizard Island. The team evaluated how the metrics of energy flow and storage that underscore critical coral reef function responded to severe coral loss. The losses followed cyclones in 2014 and 2015 and bleaching events in 2016 and 2017.

“What we found was counter-intuitive,” Dr Morais said. “In the 15 years punctuated by recurring catastrophic events of coral loss, reef fish assemblages became more, not less, productive.”

Dr Morais explained this was because the increased occurrence of larger, and presumably older, herbivorous fishes was linked to a massive increase in their favoured food: short algal turfs that quickly colonise dead corals.

Yet, the team found rates of biomass ‘recycling’ (i.e., turnover) decreased during this period, likely because large fish grow proportionally less than small ones.

“Overall, our results cautioned against interpreting the extra productivity following coral loss as necessarily positive, as it may not be stable in the long run if old fish are not replenished,” Dr Morais said.

“I am grateful for having the opportunity to develop an interesting, yet unexpected, project during my PhD, and very thrilled to accept the 2020 Haldane Prize for the paper.”

Enrico Rezende, Senior Editor of Functional Ecology said: “By combining detailed longitudinal surveys with sound theoretical analyses, Dr Morais and his colleagues provide a detailed account of the shift in energy dynamics during the degradation of a coral reef.”

The British Ecological Society (BES) awards its journal prizes annually. The prizes are for each of the seven BES journals: Functional EcologyJournal of Animal EcologyJournal of Applied EcologyJournal of EcologyMethods in Ecology and EvolutionPeople and Nature, and for the first time, Ecological Solutions and Evidence.

The winning papers are selected by the Senior Editors of the journals. The awards are presented to the winners at the BES Annual Meeting in Liverpool.

The winners receive a prize of £250, membership of the BES, a year’s subscription to the respective journal and a contribution to the costs incurred in attending the BES Annual Meeting in the UK if they wish to give a presentation on their work.

British Ecological Society

Founded in 1913, the British Ecological Society (BES) is the oldest ecological society in the world. The BES promotes the study of ecology through a range of scientific literature, funding and events, education initiatives and policy work. The society has around 6,500 members from nearly 130 different countries. www.britishecologicalsociety.org

The most extensive reef survey of the Coral Sea Marine Park ever undertaken will continue this week as scientists from ARC Centre of Excellence for Coral Reef Studies at James Cook University (Coral CoE) and Parks Australia staff set sail from Gladstone, Queensland.

The voyage will improve our understanding of coral reef health and fish communities as well as providing an opportunity to discover new marine species and measure levels of ocean pollution.

Director of National Parks Dr James Findlay said the project would monitor 20 large reef ecosystems in the Coral Sea Marine Park annually over the next three years, with this voyage heading out to the most remote and isolated reefs in the Coral Sea.

“Parks Australia is proud to be conducting this major voyage into Australia’s largest marine park,” said Dr Findlay. “This expedition will focus on the southern-most reefs, including the remote Mellish Reef which lies more than 800 kilometres off the Australian mainland.

“With a management plan coming into effect for the Coral Sea for the first time in July this year, it is very important that we monitor the health of these isolated coral reef ecosystems and increase our understanding of these amazing places. The voyage will also be assessing micro-plastics in the Coral Sea Marine Park and removing marine debris from the islets and cays.”

Voyage leader, Coral CoE’s Professor Morgan Pratchett, said this voyage would increase our understanding about how reefs are connected, the impact of coral bleaching, and reef recovery.

“Our last voyage showed that some reefs have been affected by bleaching, but we saw some signs of recovery. If no further bleaching occurs, these reefs will continue to recover and may play an important role in the broader recovery of our tropical reef systems,” said Professor Morgan Pratchett.

This is the third voyage in the first year of a three-year project to survey reefs in the Coral Sea Marine Park and follows an October voyage to the Coral Sea’s northern reefs where scientists found coral species never before recorded in Australian waters.

The voyage leaves from Gladstone O’Connell Wharf at 2 am on 4 December 2018 and disembarks at Townsville on 19 December (mid-morning).

The Coral Sea Marine Park has significant populations of internationally threatened species, as well as species found nowhere else in the world. Visit the Coral Sea page to learn more about this fascinating ecosystem.



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


Scientists have used modern genetic techniques to prove age-old assumptions about what sizes of fish to leave in the sea to preserve the future of local fisheries.

“We’ve known for decades that bigger fish produce exponentially more eggs,” said the lead author of the new study, Charles Lavin, who is a research fellow from James Cook University (JCU) and Nord University in Norway.

“However, we also found while these big fish contributed significantly to keeping the population going—they are also rare.”

Co-author Dr Hugo Harrison from the ARC Centre of Excellence for Coral Reef Studies at JCU said as fish grow older, they become more fertile and their chances of having babies increase.

“This is an age-old assumption of fisheries management—and with the help of modern genetics, we can show that this assumption is correct.”

“But the smaller fish are just as important to keeping populations going. They may have fewer babies, but they also are more abundant.”

The study used genetic parentage analysis to identify which adult coral groupers (Plectropomus maculatus) contribute to replenishing fished populations in the Great Barrier Reef Marine Park (GBRMP).

The authors found that large coral groupers are important because they are more likely to replenish the fish stocks removed from the fishery. However, smaller fish are still making a meaningful contribution.

“We show that minimum size-limits on catches are effective at protecting the reproductively mature coral grouper,” Mr Lavin said. “This ensures all fish have the opportunity to reproduce at least once prior to being caught.”

The authors said all fisheries must ensure there are enough fish reproducing to replace the portion of the population that are caught.

“We’re fortunate in the GBRMP to have measures in place that protect both the small and larger fish,” Dr Harrison said.

“These ensure our fisheries remain sustainable and can bounce back quickly after a disturbance.”

In the GBRMP, catches of coral grouper are limited by size and catch limits, as well as seasonal closures to ensure the fishery is productive and sustainable.

“It’s encouraging that these measures are effective,” Mr Lavin said.

“But it’s important that we also protect the bigger, rarer fish inside no-take marine reserves because they are super-productive,” he said.

“For the fisher, this means there will always be fish to catch.”



Lavin C, Jones G, Williamson D, Harrison H. (2021). ‘Minimum size limits and the reproductive value of numerous, young, mature female fish’. Proceedings of the Royal Society B. DOI: 10.1098/rspb.2020.2714


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


Hugo Harrison (Townsville, Australia)
P: +61 (0) 499 523 939

Charles Lavin (currently travelling)
E: charles.p.lavin@nord.no


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



Scientists say outdated assumptions around gender continue to hinder effective and fair policymaking and action for climate mitigation and adaptation.

Lead author of a new study, Dr Jacqueline Lau from the ARC Centre of Excellence for Coral Reef Studies at James Cook University (Coral CoE at JCU) and WorldFish, said gender—alongside other identities like race, class and age—has a powerful influence on people’s experience of, and resilience to, climate change.

She said the four most common and interlinked assumptions found are: women are innately caring and connected to the environment; women are a homogenous and vulnerable group; gender equality is a women’s issue and; gender equality is a numbers game.

“Although there is a global mandate to work towards gender equality in climate change mitigation and adaptation, efforts are hindered by a set of assumptions about gender, long critiqued in development studies,” Dr Lau said.

The study draws on post-2014 gender and climate change literature, to give an overview of how the gender assumptions manifest across recent work in adaptation, mitigation and broader climate change policy, practice and research.

The review of the literature takes a closer look at how these assumptions narrowly diagnose the causes of gender inequality.

“As a result, we see too many strategies that have unintended—and even counterproductive—consequences,” said Dr Pip Cohen, from WorldFish.

“For instance, strategies that target women only may overburden them, cause a backlash, or obscure the vulnerabilities of other groups.”

The study offers lessons for a more informed pursuit of gender equality in climate change research, policy and practice.

The authors said progressing gender equality means breaking down stereotypes and prejudices about gender—creating environments to enable all people to exercise their agency to cope, change and adapt.

Dr Lau said she was surprised to find so many examples of gender assumptions in climate change practice. She explained that a first step in disrupting these assumptions is to lay them bare and explain why development research has found them to be problematic.

“The social and cultural expectations about what it is to be a woman or a man in any given society will shape people’s wellbeing,” Dr Lau said.

She said alongside efforts to dismantle broader barriers to gender equality, better and more coordinated efforts are needed from practitioners and researchers to disrupt and counteract unhelpful assumptions.

“Pursuing gender equality in climate change policy and practice is critical, and decades of experience in development offer lessons for how to do it well,” Dr Lau said.

“Ultimately, we want to see equitable opportunities for all people to realise their full potential. Where no one is left behind.”



Lau J, Kleiber D, Lawless S, Cohen P. (2021). ‘Gender equality in climate policy and practice hindered by assumptions’. Nature Climate Change. DOI: 10.1038/s41558-021-00999-7


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.


Dr Jacqueline Lau (Townsville, Australia)
P: +61 (0)403 990 738

Dr Pip Cohen (travelling on/off 4 & 5 March)
P: +61 (0)400 468 255 (via WhatsApp will work best)
E: p.cohen@cgiar.org


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


WorldFish is an international, nonprofit research and innovation institution that creates, advances, and translates aquatic food systems science into scalable solutions. We vision an inclusive world of healthy, well-nourished people and a sustainable blue planet, now and in the future. Our mission is to end hunger and advance progress on the 2030 Sustainable Development Goals through science and innovation to transform food, land, and water systems with aquatic foods for healthier people and the planet.

For over 45-years, WorldFish’s data, evidence, and insights have shaped practices, policies, and investments to end hunger and advance sustainable development in low- and middle-income countries.  We have a global presence across 20 countries in Asia, Africa, and the Pacific, with 460 staff of 30 nationalities deployed where the greatest sustainable development challenges can be addressed through holistic aquatic food systems solutions. Embedded in local, national, and international partnerships, our work sets agendas, builds capacities, and supports decision-making for climate action, food and nutrition security, sustainable fisheries and aquaculture, blue economy, OneHealth, and AgriTech, integrating gender, youth, and social inclusion.

A core element of the 2030 WorldFish Research and Innovation Strategy: Aquatic Foods for Healthy People and Planet is focused on building resilience of aquatic food systems to shocks, which is critical to COVID-19 response and recovery.

WorldFish is part of One CGIAR, the world’s largest agricultural research and innovation network.

For the first time, scientists have assessed how many corals there are in the Pacific Ocean—and evaluated their risk of extinction.

While the answer to “how many coral species are there?” is ‘Googleable’, until now scientists didn’t know how many individual coral colonies there are in the world.

“In the Pacific, we estimate there are roughly half a trillion corals,” said the study lead author, Dr Andy Dietzel from the ARC Centre of Excellence for Coral Reef Studies at James Cook University (Coral CoE at JCU).

“This is about the same number of trees in the Amazon, or birds in the world.”

The results are crucial for the research and conservation of corals and coral reefs as they decline across the world due to the effects of climate change.

“We need to know the abundance of a species to assess its risk of extinction,” Dr Dietzel said. “However, there is very little data on most of Earth’s wild animal and plant species—not just corals.”

Dr Dietzel said the eight most common coral species in the region each have a population size greater than the 7.8 billion people on Earth.

The findings suggest that while a local loss of coral can be devastating to coral reefs, the global extinction risk of most coral species is lower than previously estimated.

Extinctions could instead unfold over a much longer timeframe because of the broad geographic ranges and huge population sizes of many coral species.

Co-author Professor Sean Connolly, from Coral CoE at JCU and the Smithsonian Tropical Research Institute, said the study’s new analysis of the 80 species considered by the IUCN to have an elevated extinction risk shows that 12 of those species have estimated population sizes of more than one billion colonies.

“As an example, the finger-coral, Porites nigrescens, ranks amongst the ten most abundant species we examined. It’s also not considered to be highly susceptible to coral bleaching—yet it is currently listed by IUCN as vulnerable to global extinction,” Prof Connolly said.

Co-author Professor Michael Bode from Coral CoE at JCU and the Queensland University of Technology said, “One third of the rarest species in our analysis—covering the bottom ten percent of species abundances—are nonetheless listed by the IUCN as being of Least Concern.”

The study measured the population sizes of more than 300 individual coral species on reefs across the Pacific Ocean, from Indonesia to French Polynesia. The scientists used a combination of coral reef habitat maps and counts of coral colonies to estimate species abundances.

Co-author Professor Terry Hughes from Coral CoE at JCU said the study results have major implications for managing and restoring coral reefs.

“We counted an average of 30 corals per square metre of reef habitat. This translates into tens of billions of corals on the Great Barrier Reef—even after recent losses from climate extremes,” Prof Hughes said.

“Coral restoration is not the solution to climate change. You would have to grow about 250 million adult corals to increase coral cover on the Great Barrier Reef by just one percent.”

He said the study highlights the opportunity for action to mitigate the threats to reef species—and well before climate change causes global extinctions—to make an eventual recovery of reef coral assemblages possible.

“The challenge now is to protect wild populations of corals, because we could never replace more than a tiny percentage of them. Prevention is better than cure,” Prof Hughes said.

“Given the huge size of these coral populations, it is very unlikely that they face imminent extinction. There is still time to protect them from anthropogenic heating, but only if we act quickly on reducing greenhouse gas emissions.”


Dietzel A, Bode M, Connolly S, Hughes T. (2021). ‘The population sizes and global extinction risk of reef-building coral species at biogeographic scales’. Nature Ecology & Evolution. DOI: 10.1038/s41559-021-01393-4


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.


Dr Andreas Dietzel (Townsville, Australia)
+61 (0)432 916 224

Prof Sean Connolly (Panama, Central America)
P: (available on request)
E: ConnollyS@si.edu

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

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

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

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


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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


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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


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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 


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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


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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


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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


Australian Research Council Pandora

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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