Monitoring of nature reserves via social media and deep learning

National University of Singapore

Environmental biology researchers at the National University of Singapore (NUS) have developed an efficient method for rapidly identifying and classifying human activities within nature reserves at the global level, using social media and deep learning techniques.

Many people visit nature reserves for various reasons, such as hiking to keep fit. Despite these benefits, it is clear that having too many visitors could lead to overcrowding and negatively impact conservation efforts. Consequently, to implement more effective land use management strategies for crowd control, governments need to gain insights into how these green spaces are used. However, as most of these nature reserves cover large land areas, using conventional field surveys to monitor human activities within them can be costly and time-consuming.

The research team, led by Associate Professor L Roman CARRASCO from the Department of Biological Sciences under the NUS Faculty of Science along with his PhD student, Mr Timothy Bing Lun YEE, has developed a technique to process social media images taken within protected areas (PAs) as a proxy for identifying human activities within them. By parsing these images through a deep learning image tagging model, the human activities depicted within them are automatically detected. These tagged images are then subsequently grouped into distinct categories of human activities. They analysed a total of 87,090 photos from 2,813 PAs in 207 countries for this study.

These findings have been published in Scientific Reports.

The researchers made some interesting observations. Most notably, distinct clusters of activity types across PAs aligned closely with expectations. For instance, there were many photographs of animals and plants in Southeast Asian PAs, while European PAs had numerous photographs of historic castles. Also, PAs within the same country showed similar activities, even if they had different physical environments.

In explaining the significance of this work, Mr Yee said, “While there have been similar studies, this is possibly the first study that tries to investigate human activities within PAs on a global scale. It demonstrates the utility of social media and deep learning in empowering researchers to investigate pressing environmental issues at a much larger scale.”

Prof Carrasco added, “The team hopes that this technique can be adopted by nature organisations to monitor land use patterns in nature reserves efficiently and cost-effectively, enabling more targeted conservation efforts to protect ecosystems despite increasing visitor numbers.”

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Journal

Scientific Reports

DOI

10.1038/s41598-024-64115-3 

Article Title

Applying deep learning on social media to investigate cultural ecosystem services in protected areas worldwide

Sea lion camera crews help researchers explore previously unmapped ocean habitats

Scientists equipped Australian sea lions with cameras and used the video data to identify unknown ocean habitats in southern Australia

Peer-Reviewed Publication

Frontiers

 

image: 

Cameras and tracking instruments were glued to small pieces of neoprene that were then glued to the fur of the sea lions. Image: Nathan Angelakis.

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Credit: Image: Nathan Angelakis

The world’s seabeds are little explored, and the knowledge we have is patchy. Using remotely operated underwater vehicles to learn about seabeds is expensive, requires certain weather conditions, and is difficult in deep, remote, and offshore habitats.

To circumvent these challenges, researchers in Australia have now enlisted endangered Australian sea lions (Neophoca cinerea) to carry cameras. The resulting videos allowed the researchers to identify previously unmapped benthic habitats used by the sea lions on the continental shelf. They published their results in Frontiers in Marine Science.

“Using animal-borne video and movement data from a benthic predator is a really effective way of mapping diverse benthic habitats across large areas of the seabed,” said first author Nathan Angelakis, a PhD student with The University of Adelaide and the South Australian Research and Development Institute (Aquatic Sciences). “These data are useful both for mapping critical habitats for an endangered species such as the Australian sea lion, and more broadly, for mapping unexplored areas of the seabed.”

Tracking sea lions

For the project, supported with funding from The Australian Government and The Ecological Society of Australia, eight adult female Australian sea lions from Olive Island and Seal Bay colonies were equipped with small and light-weight cameras. Cameras and tracking instruments were glued to small pieces of neoprene that were then glued to the fur of the sea lions. In total, the filming and tracking equipment weighed less than 1% of the sea lions’ body weight to prevent dragging effects and allow the animals to move without restrictions. Recordings were made over two to three days.

“We deployed the instruments on adult females so we could recover the equipment a few days later when they returned to land to nurse their pups,” Angelakis explained. “We used satellite-linked GPS loggers on the sea lions, which meant we could track their position in real-time and knew when they had returned to the colony.”

Predicting ocean habitats

From the animal-borne videos – 89 hours of recordings in total – the researchers identified six benthic habitats: macroalgae reef, macroalgae meadow, bare sand, sponge/sand, invertebrate reefs, and invertebrate boulder.

The researchers then used machine learning models to predict large habitat areas across the continental shelf of southern Australia. To do so, they also incorporated oceanographic and environmental factors which may be important drivers of the structure and distribution of these habitats. The oceanographic data that was incorporated into the models was based on 21 years of observation and measurements.

“The sea lions from both locations covered quite broad areas around the colonies. In our calculations, we kept the area in which we predicted habitats small to maximize the precision of our predictions,” Angelakis said. “This allowed us to model benthic habitats across more than 5,000 square km of the continental shelf.”

As seen by sea lions

The habitats the sea lions filmed were different than in other, previously mapped regions of South Australia. This could be due to contrasting oceanographic/environmental conditions, as well as sea lions not using or traveling through certain habitats or preferring certain ones over others. Some habitats in the region might have been missed, the researchers pointed out.

The study nevertheless contributes greatly to knowledge about these seabeds and provides critical information about an endangered species, the populations of which have declined by more than 60% over the past 40 years. In addition, it can also be used to survey and assess other marine species of interest that are observed in the video.

The researchers said that exploring these habitats by way of animal-borne video does offer an efficient and cost-effective method for future mapping endeavors. Assessing marine areas from the perspective of a predator, rather than from a more traditional anthropocentric perspective can improve scientists’ understanding of benthic environments and develop more comprehensive maps of the seabed.

Equipping the sea lions 

The researchers equipped eight adult female Australian sea lions from Olive Island and Seal Bay colonies were equipped with small and light-weight cameras. Image: Roger Kirkwood.

Credit

Image: Roger Kirkwood

Journal

Frontiers in Marine Science

DOI

10.3389/fmars.2024.1425554 

Method of Research

Experimental study

Subject of Research

Animals

Article Title

Using sea lion-borne video to map diverse benthic habitats in southern Australia

Article Publication Date

7-Aug-2024

 BUDDHA'S  DIAMOND MIND 

X-ray imagery of vibrating diamond opens avenues for quantum sensing

Atom-scale measurements of diamond lead to new equation related to quantum sensors

Peer-Reviewed Publication

DOE/Argonne National Laboratory

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When it comes to materials for quantum sensors, diamond is the best game in town, says Cornell University professor Gregory Fuchs. Now he and a team of scientists have upped diamond’s game by generating exquisite imagery of diamond undergoing microscopic vibrations.

The team, comprising researchers at the U.S. Department of Energy’s (DOE) Argonne National Laboratory, Cornell and Purdue University, achieved a two-fold advance for quantum information science.

First, pulsing the diamond with sound waves, they took X-ray images of the diamond’s vibrations and measured how much the atoms compressed or expanded depending on the wave frequency.

Second, they connected that atomic strain with another atomic property, spin — a special feature of all atomic matter — and defined the mathematical relationship between the two.

The findings are key for quantum sensing, which draws on special features of atoms to make measurements that are significantly more precise than we’re capable of today. Quantum sensors are expected to see widespread use in medicine, navigation and cosmology in the coming decades.

“We’re connecting two sides of an equation — the spin side and the strain side — and directly comparing what's going on in the diamond … It was very satisfying to directly hammer both of them down.” — Gregory Fuchs, Cornell University

Shake and spin

Scientists use spin to encode quantum information. By determining how spin responds to strain in diamond, the team provided a manual on how to manipulate it: Give the diamond a microshake in this way, and the spin shifts this much. Shake the diamond that way, and the spin shifts that much.

The research, published in Physical Review Applied, is the first time anyone has directly measured the correlation in diamond at gigahertz frequencies (billions of pulses per second). It is also part of a larger effort in the quantum science community to precisely connect atomic strain and the associated spin in a broad range of materials. For example, researchers at Argonne and the University of Chicago previously measured spin-strain correlations in silicon carbide, another star material that researchers are engineering for quantum applications.

The group’s research is supported in part by Q-NEXT, a DOE National Quantum Information Science Research Center led by Argonne.

“We’re connecting two sides of an equation — the spin side and the strain side — and directly comparing what's going on in the diamond,” said Fuchs, a professor in Cornell’s School of Applied and Engineering Physics and a collaborator within Q-NEXT. “It was very satisfying to directly hammer both of them down.”

Solving the spin-strain equation

The two sides of the equation were hammered down hundreds of miles apart.

For the spin measurements, scientists at Cornell University in New York measured how spin responded to the sound waves pulsing through the diamond using a one-of-a-kind device developed by researchers at Cornell and Purdue.

For the strain measurements, Cornell graduate student and paper author Anthony D’Addario drove 700 miles to Argonne in Illinois to use the Advanced Photon Source (APS), a DOE Office of Science user facility. The 1-kilometer-circumference machine generates X-rays that allow researchers to see how a material behaves at the atomic and molecular level. Having generated images of strain in other materials for quantum technologies, it would now do the same for diamond. The team used an X-ray beam jointly operated by the APS and Argonne’s Center for Nanoscale Materials, also a DOE Office of Science user facility, to take strobe-light-like pictures of the diamond’s atoms as they shook back and forth.

They focused on a particular site within the diamond: an irregularity called a nitrogen vacancy (NV) center, which consists of an atom-sized hole and a neighboring nitrogen atom. Scientists use NV centers as the basis for quantum sensors.

The APS’s high-resolution images enabled the team to measure the atoms’ movement near the diamond’s NV centers to one part in 1,000.

“Being able to use the APS to unambiguously look at or quantify the strain near the NV center as it's being modulated by these beautiful acoustic resonators developed at Purdue and Cornell — that allows us to get the story locally near the NV centers,” said Argonne scientist and Q-NEXT collaborator Martin Holt, who is also an author on the paper. “That’s always been the beauty of hard X-rays: being able to look entirely through complex systems and get quantitative answers about what's inside.”

With both spin and strain measurements in hand, Fuchs and team related the two in an equation that, satisfyingly, agreed with theory.

“The most exciting part was in doing the analysis. We ended up finding a new number that related the spin and strain, and it ended up agreeing with some theory and previous measurements,” D’Addario said.

Acoustic engineering

Spin can be manipulated in a few ways. The most popular is to use electromagnetic waves. Using acoustic waves is less common.

But it has advantages. For one, acoustic waves can be used to manipulate spin in ways that can’t be achieved with electromagnetic fields.

For another, acoustic waves can protect the quantum information encoded in the spin. Quantum information is fragile and falls apart when disturbed by its environment, a process called decoherence. One of the aims of quantum research is to stave off decoherence long enough for the information to be processed successfully.

“It's a little counterintuitive that adding sound to a system makes it better, but it’s a bit like turning on a white noise generator to not hear a conversation,” Holt said. “You can use the acoustic waves to protect the quantum bit from decoherence. You’re shifting what the system is sensitive to in a way that protects it from these other sound processes.”

There’s also the advantage of miniaturization. Whereas a 1-gigahertz electromagnetic wave is roughly a foot long, a gigahertz acoustic wave is tiny, about the width of a human hair. That small wavelength allows scientists to place multiple similar devices in a small setup and still ensure that their signals won’t cross each other.

“If you want there not to be a lot of discussion or interference between neighboring devices, then you can use acoustic-wave devices, which can be very confined,” Fuchs said.

Combining these advantages with diamond makes for a superior quantum sensor. As a host for quantum information, diamond enables long information lifetimes, can operate at room temperature and provides reliable measurements.

“I would say most people would agree with me that, for quantum sensors, diamond is king,” Fuchs said.

Cross-discipline collaboration was key to the effort.

“Because of the complexity and sensitivity of these systems, there are many different things that can move quantum phenomena around,” Holt said. “Being able to carefully baseline the response to individual pieces requires correlation. That’s a multidisciplinary question, and that's something that Q-NEXT is very well-suited to answer. The investment of Q-NEXT in terms of creating in-operation environments for quantum systems in these facilities is really paying off.”

This work was supported by the DOE of Science National Quantum Information Science Research Centers as part of the Q-NEXT center.

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Journal

Physical Review Applied

Article Title

Stroboscopic x-ray diffraction microscopy of dynamic strain in diamond thin-film bulk acoustic resonators for quantum control of nitrogen-vacancy centers

Article Publication Date

7-Aug-2024

H = SUPERBUG

Superbugs spread to family members of recently hospitalized patients

Study suggests hospitals play a role in community spread of antibiotic resistant infections

Society for Healthcare Epidemiology of America

ARLINGTON, Va. (August 7, 2024) — Family members of patients recently discharged from the hospital may have a higher risk of getting an antibiotic-resistant infection, often called a superbug, even if the patient was not diagnosed with the same infection, suggesting hospitals play a role in the community spread of resistant bacteria, according to study in Infection Control & Hospital Epidemiology, the journal of the Society for Healthcare Epidemiology of America.

When recently hospitalized patients were diagnosed with the superbug — Methicillin-resistant Staphylococcus aureus infection (MRSA) — the risk to relatives living with them was even higher. The longer the relative’s hospital stay, even without a MRSA diagnosis, the higher the risk to family members.

“Patients can become colonized with MRSA during their hospital stay and transmit MRSA to their household members,” said Aaron Miller, PhD, lead researcher on the study and research assistant professor of internal medicine-infectious diseases at University of Iowa. “This suggests hospitals contribute to the spread of MRSA into the community through discharged patients who are asymptomatic carriers.”

Miller recommends hospitals enhance infection control practices, including testing for MRSA colonization, especially at discharge, even with there are no symptoms of infection. He said MRSA colonization and infections could be tracked among hospital patients and their household contacts to identify and mitigate transmission more effectively.

“This important study illustrates the risk of spread of resistant pathogens related to healthcare and highlights the essential importance of core infection practices,” said SHEA President Thomas Talbot, M.D., chief hospital epidemiologist at Vanderbilt University Medical center. Talbot was not involved with the research. “Hand hygiene, environmental cleaning, and standard interventions to reduce Staphylococcal colonization are crucial to preventing the spread of resistant bacteria in healthcare settings,”

MRSA infections are known as superbugs because they do not respond to common antibiotics, making them difficult to treat. MRSA generally occurs in people who have been in a hospital or another health care setting, such as a nursing home, but MRSA also spreads in communities outside the hospital, usually through skin-to-skin contact. Most people with MRSA have no symptoms, but the bacteria can cause painful swelling if it gets under the skin, and it can be deadly if it spreads to other parts of the body, such as blood or lungs.

Researchers used a large database of insurance claims that included 158 million enrollees with two or more family members on the same plan to learn about how MRSA spread to after someone in a household had been in the hospital.

Reviewing 424,512 MRSA cases among 343,524 insured people, the study found 4,724 cases of MRSA being potentially transmitted to a family member from a relative who had recently been in the hospital and had a diagnosis of MRSA.  They also found 8,064 potential transmissions of MRSA after the hospitalization of a family member who did not have a MRSA infection.

“It is important not over-emphasize the hospital stay risk,” Miller said. “While we identified a significant risk factor for transmission in the household and community the absolute risk remains relatively low.”

People exposed to a recently hospitalized family member with MRSA were more than 71 times, or 7000%, more likely to get a MRSA infection compared to enrollees who did not have a family member who had been in the hospitalized or exposed to MRSA in the previous 30 days.

Having a family member in the household who was hospitalized but did not have MRSA increased the chances of a relative getting MRSA in the month after discharge by 44%.

The more time the family member spent in the hospital, the higher the likelihood someone in their household would get MRSA. If the patient was in the hospital one to three days in the previous month, the chance of a relative getting MRSA increased by 34% compared to people with no recent hospitalizations in their household. If a family member was hospitalized for four to 10 days, the chances of MRSA infection in a relative were 49% higher, and with hospitalizations longer than 10 days the odds of relative in the same household getting an infection rose by 70% to 80%.

Other factors associated with MRSA infections among household members included number of other illnesses, prior antibiotic usage, and the presence of young children in the family.

The study, “Hospitalizations among family members increase the risk of MRSA infection in a household,” was published online in Infection Control & Hospital Epidemiology on August 7.

 

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About ICHE
Published through a partnership between the Society for Healthcare Epidemiology of America and Cambridge University Press, Infection Control & Hospital Epidemiology provides original, peer-reviewed scientific articles for anyone involved with an infection control or epidemiology program in a hospital or healthcare facility. ICHE is ranked 24th out of 94 Infectious Disease Journals in the latest Web of Knowledge Journal Citation Reports from Thomson Reuters.

The Society for Healthcare Epidemiology of America (SHEA) is a professional society representing more than 2,000 physicians and other healthcare professionals around the world who possess expertise and passion for healthcare epidemiology, infection prevention, and antimicrobial stewardship. The society’s work improves public health by establishing infection-prevention measures and supporting antibiotic stewardship among healthcare providers, hospitals, and health systems. This is accomplished by leading research studies, translating research into clinical practice, developing evidence-based policies, optimizing antibiotic stewardship, and advancing the field of healthcare epidemiology. SHEA and its members strive to improve patient outcomes and create a safer, healthier future for all. Visit SHEA online at shea-online.org, facebook.com/SHEApreventingHAIs and twitter.com/SHEA_Epi.

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Journal

Infection Control and Hospital Epidemiology

DOI

10.1017/ice.2024.106 

Subject of Research

People

Article Title

Hospitalizations among family members increase the risk of MRSA infection in a household

Article Publication Date

7-Aug-2024

New report on Great Barrier Reef shows coral cover increases before onset of serious bleaching, cyclones

Coral cover has increased in all three regions on the Great Barrier Reef and is at regional highs in two of the three regions according to a report by the Australian Institute of Marine Science (AIMS). But the results come with a note of caution

Australian Institute of Marine Science

Most of the underwater surveys contributing to these findings, published today, were conducted before and during the recent mass bleaching event, one of the most extensive and serious on record, and have not yet captured how many corals survived or died following the bleaching.    

Surveys in the Central region were also completed before the passage of tropical Cyclone Jasper in December 2023.    

AIMS’ Long-Term Monitoring Program (LTMP) leader Dr Mike Emslie said coral cover increases were a positive sign but did not reflect the potentially destructive consequences of the 2024 mass bleaching event. 

“We saw evidence of early onset mortality, particularly in the Southern region, but the full picture of mortality was not yet apparent during this year’s surveys,” he said.

“While bleached corals are very stressed, they are still alive and are recorded as live coral on our surveys. 

“Some types of corals can remain bleached for months, remaining on a knife edge between survival and death. This is why returning and repeating surveys of the reefs in this vast, complex and dynamic system is so important. This year’s results serve as a very important reference against which to measure the impacts of the summer’s events.”

The next (LTMP) survey season recommences in September and will capture impacts on coral cover from this summer’s mass bleaching event and the cyclones, with a full assessment complete by mid-2025.  

“Climate change remains the greatest threat to the Reef because it drives these mass bleaching events. This most recent one was the fifth such event since 2016. These more frequent and extensive marine heatwaves will lead to shortened ‘windows’ for coral recovery. Recent gains, while encouraging, can be lost in a short amount of time,” Dr Emslie said.

Surveys were conducted at 94 Reefs spread through the Northern, Central and Southern Great Barrier Reef between August 2023 and June 2024.    

The Report recorded the following average hard coral coverage:    

• Northern region (north of Cooktown) – 39.5%, up from 35.8% last year;    
• Central region (Cooktown to Proserpine) – 34%, up from 30.7%;   

• Southern region (south of Proserpine) – 39.1%, up from 34%.    

The AIMS report finds that small rises in coral cover this year bring the Northern and Central regions to their highest levels in 38 years of monitoring.  

The surveys also found that crown-of-thorns starfish outbreaks have persisted on some reefs in the Southern region.    

The long term monitoring team surveyed reefs off Townsville after the passage of tropical Cyclone Kirrily in late January, finding evidence of storm damage and declines in hard coral cover ranging from 6% to 10% at Kelso, John Brewer, Helix and Chicken Reefs. Other reefs appear to have escaped with little impact.    

AIMS Research Program Director Dr David Wachenfeld said the regional increases in coral cover are encouraging, showing the Reef’s capacity for recovery after reaching their lowest levels within the last 15 years. However, climate change and other disturbances mean this recovery is fragile and Reef resilience is not limitless.    

“In many ways the Reef has had some lucky escapes in recent years. The 2020 and 2022 mass bleaching events had levels of heat stress that were not as intense as the 2016 and 2017 events or the 2024 event. Coupled with very few other events causing widespread coral death, that has led to the levels of coral cover increase we have seen,” he said.   

“But the frequency and intensity of bleaching events is unprecedented, and that is only forecast to escalate under climate change, alongside the persistent threat of crown-of-thorns starfish outbreaks and tropical cyclones”.    

Aerial surveys undertaken by AIMS and the Great Barrier Reef Marine Park Authority in February and March found bleached corals in the shallows of 73% of reefs surveyed across all three regions.  

In recent weeks, AIMS scientists in separate monitoring programs observed substantial mortality in reefs that were particularly hard hit by the 2024 event.  

“We are only one large scale disturbance event away from a reversal of the recent recovery. The 2024 bleaching event could be that event – almost half of the 3000 or so reefs that make up the marine park experienced more heat stress than ever recorded,” Dr Wachenfeld said.    

“We still don’t know how much mortality this event has caused. Our monitoring over the next 12 months will help us to understand how this bleaching event stacks up against the others in the last decade.” 

AIMS CEO Professor Selina Stead said AIMS was prioritising research to develop scientific solutions to boost reef resilience under a warming climate.   

“Climate change is increasing pressure on reef systems around the world,” she said.  “The 2024 bleaching event was part of the fourth global bleaching event, announced in April.

“These vitally important ecosystems that millions rely upon need strong greenhouse gas emissions reduction, science-based management of local pressures, and input from multiple fields of research if they are to endure.

“At AIMS we are developing a toolbox of interventions to help reefs adapt to and recover from the effects of climate change.” 

Background    

The LTMP quantifies long term trends in the status of coral communities across the Great Barrier Reef.   

Researchers use hard coral cover as one indicator of the condition of each reef. Percentage hard coral cover is estimated by trained scientists during manta tow surveys and is a metric which allows AIMS scientists to provide an overview of the Great Barrier Reef’s status and keep policy makers, managers and other scientists informed in a timely manner.   

The LTMP also does more detailed surveys on fixed sites on 71 reefs across the Great Barrier Reef.  The detailed information includes what types of corals and species of fish are present, their abundance, and causes of mortality like crown-of-thorns starfish numbers, coral disease and bleaching observations.   

The LTMP contributes to the Reef 2050 Integrated Monitoring and Reporting Program. Learn more about the LTMP and access detailed data displays at the level of individual reefs or regions.

Download images and vision here.

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Method of Research

Data/statistical analysis

Subject of Research

Animals

Long-term coral reef monitoring continues to deliver crucial insights

American Institute of Biological Sciences

As the effects of a changing climate and other ecological insults compound, many coral reefs face severe perturbations and a generally poor prognosis for recovery. In an article published in BioScience's new "Perspective and Insight" category, Dr. Peter J. Edmunds of California State University, Northridge, argues for the continued monitoring of coral reefs, even when the seascapes they inhabit are in a significantly degraded state.

Drawing from his ongoing 37-year study in the US Virgin Islands, Edmunds argues that "only consistent, rigorous, and detail-oriented monitoring can document the losses of coral that already have taken place and provide constrained glimpses of the benthic communities that will dominate shallow, tropical marine habitats in the future." Dr. Edmunds's research relies heavily on photoquadrats—one-by-one meter underwater photographs taken at fixed locations over time. These images provide a consistent, quantifiable record of changes in coral cover and community composition, allowing researchers to track the health reef communities in great detail.

Edmunds' monitoring has revealed unexpected resilience in some cases, alongside devastating losses in others, as well as other ecological surprises that challenge our understanding of reef dynamics. For example, two major hurricanes in 2017 had less impact on coral cover than a single hurricane in 1989—likely because chronic disturbances had resulted in a more hurricane-resilient low-cover state, says Edmunds. He continues, stating that long-term monitoring "supports an objective test of the role of acute versus chronic disturbances in driving changes on the reefs."

In concluding, Edmunds argues for the great value of ongoing monitoring, both for conservation purposes and to provide a greater understanding of underlying ecological processes: "Monitoring remains the essential tool through which there is any hope of keeping up with detecting the fast pace of changes affecting the natural world in the twenty-first century."

 

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Journal

BioScience

DOI

10.1093/biosci/biae046 

Method of Research

Experimental study

Subject of Research

Animals

Article Title

Why keep monitoring coral reefs?

Article Publication Date

9-Aug-2024

New 400-year temperature record shows Great Barrier Reef is facing catastrophic damage, researchers warn

Sea surface temperatures have reached critical levels for mass coral bleaching

Peer-Reviewed Publication

University of Wollongong

 

video: 

Removing a skeletal core from a coral colony in the Coral Sea

view more 

Credit: Tom DeCarlo, Tulane University

The Great Barrier Reef is under critical pressure, with warming sea temperatures and mass coral bleaching events threatening to destroy the remarkable ecology, biodiversity, and beauty of the world’s largest coral reef, according to new research published today.

‘Highest ocean heat in four centuries places Great Barrier Reef in danger’, published in Nature (8 August), led by University of Wollongong (UOW) Honorary Fellow and University of Melbourne Lecturer Dr Benjamin Henley, provides new evidence of the impact that rising sea surface temperatures have had, and will continue to have, on Australia’s ecological jewel.

The research reconstructs 400 years of summer sea surface temperatures in the Coral Sea. The results chronicle extreme recent ocean heat that has led to mass coral bleaching on the Great Barrier Reef.

Last week, UNESCO’s World Heritage Committee handed down its final decision on the state of the Great Barrier Reef, declining to list the Reef as in danger. However, the scientists have pushed back and say, based on their new evidence, the Great Barrier Reef is absolutely in danger.  

Dr Henley and his team combined sea surface temperature reconstructions using geochemical data from coral cores previously collected from the region. They also analysed climate model simulations of sea surface temperatures run with and without climate change, finding that human-caused climate change is to blame for the rising temperatures in the region.

The recent mass bleaching events coincide with five of the six hottest years in the new 400-year-long record. In the years 2024, 2017 and 2020, the Coral Sea reached 400-year highs, with 2024 being the warmest on record by a large margin. The recent heat events in 2016, 2004, and 2022, were the next warmest three years on record. The impact on the Great Barrier Reef’s unparalleled ecology and biodiversity over repeated sequences of mass coral bleaching is devastating.

“When I plotted the 2024 data point, I had to triple check my calculations – it was off the charts – far above the previous record high in 2017. I could almost not believe it. Tragically, mass coral bleaching has occurred yet again this year,” Dr Henley said.  

“In the absence of rapid, coordinated and ambitious global action to combat climate change, we will likely witness the demise of one of Earth’s most spectacular natural wonders.

“When you compile all of the evidence we have, it’s the inevitability of the impacts on the reef in the coming years that really gets to me.”

Professor Helen McGregor, from UOW’s Environmental Futures, who is the second author of the study, said urgent action is needed to prevent devastation of one of the world’s most important ecosystems.

“There is no ‘if, but or maybe’—the ocean temperatures during these bleaching events are unprecedented in the past four centuries.

“The Great Barrier Reef is facing catastrophe if anthropogenic climate change is not immediately addressed. The very corals that have lived for hundreds of years and that gave us the data for our study are themselves under serious threat,” Professor McGregor said.

“Our climate model analysis confirms that human influence on the climate system is responsible for the rapid warming in recent decades,” said Dr Henley, who undertook most of the study as a post-doctoral researcher at UOW, where he is now an Honorary Fellow.

“Without urgent intervention, our iconic Great Barrier Reef is at risk of near-annual bleaching from high ocean temperatures. The Reef’s fundamental ecological integrity and outstanding universal value are at stake.

“We have many of the key solutions to stop climate change; what we need is a step change in the level of coordinated national and international action to transition to net zero.

“We can never lose hope. Every fraction of a degree of warming we avoid will lead to a better future for the human and natural systems of our planet. 

“We hope that our study equips policymakers with more evidence to pursue deeper cuts in greenhouse gas emissions internationally.”

Coral bleaching occurs when stress causes the corals to expel the algae that live in their tissue. The algae give corals their vibrant colours and without them the coral’s white skeleton is exposed. Stress from environmental disturbances and declining water quality can lead to bleaching, but recent warming in sea temperatures has led to bleaching on a mass scale. Corals can recover from bleaching events if the stress trigger, such as extreme ocean warming, is reduced for a significant period. The reef has experienced five major mass coral bleaching events since 2016.

While the Great Barrier Reef is the world’s largest coral reef system, the groundbreaking research has implications for coral reef systems throughout the world, highlighting the link between the long-term trajectory of extreme ocean temperatures and the ecological health and biodiversity of these complex and crucial ecosystems.

Researchers from Securing Antarctic’s Environmental Future, UOW, University of Melbourne, The University of Queensland, the Australian Institute of Marine Science, Tulane University (USA), and Columbia University (USA) contributed to the paper.

UOW is committed to addressing the United Nations Sustainable Development Goals, which provide a shared blueprint to achieve a better and more sustainable future for everyone. These projects address Goal 13, Climate Action; and Goal 14, Life Below Water.

‘Highest ocean heat in four centuries places Great Barrier Reef in danger’ is published in Nature.  https://www.nature.com/articles/s41586-024-07672-x

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Journal

Nature

DOI

10.1038/s41586-024-07672-x 

Subject of Research

Animals

Article Title

Highest ocean heat in four centuries places Great Barrier Reef in danger

Article Publication Date

7-Aug-2024