Back-to-back cyclones and flood plume impacts on the Great Barrier Reef

Back-to-back cyclones have exposed the Great Barrier Reef to extensive and persistent flood plumes from Ingham up to Cape York Peninsula, with terrestrial runoff lathering coral reef and seagrass ecosystems for weeks.

Scientists from James Cook University’s Centre for Tropical Water and Aquatic Ecosystem Research  (TropWATER) have reported freshwater coral bleaching and seagrass damage, with flood plumes stretching more than 700km along the Great Barrier Reef coastline, and reaching some areas of the mid and outer reefs.

TropWATER water quality scientist Jane Waterhouse said we mustn’t underestimate the impacts of terrestrial runoff on marine ecosystems.

“Coastal and marine ecosystems do not like freshwater, let alone the sediments, nutrients and pesticides that are carried along with it,” she said.

“Seagrass meadows are highly vulnerable in these extreme events from both physical wave damage and the effects of low light from murky waters. Coral reefs can experience high stress resulting in isolated freshwater bleaching, and there is also a risk of macroalgae blooms out-competing coral reefs in the longer term,” she said.

Inshore ecosystems are critical for dugongs and turtles while also providing nursery habitat for key fish species, and high value recreational and tourist areas in the Great Barrier Reef.

Tropical Cyclone Jasper crossed north of Cairns in December, discharging in the order of 20,000 GL of freshwater – the equivalent of around 40 Sydney Harbours – into the northern Great Barrier Reef. Cyclone Kirrily, which crossed Townsville on 25 January, resulted in less rain.

TropWATER scientists have been tracing and assessing the damage of flood plumes on marine ecosystems, sampling flood plume waters, analysing flood satellite imagery and surveying damage to seagrass meadows, as part of the Marine Monitoring Program.

TropWATER’s Dr Stephen Lewis said following Tropical Cyclone Jasper the team sampled flood waters from the Barron, Russell Mulgrave and Tully rivers, with preliminary observations suggesting elevated levels of nutrients and sediments in inshore coral and seagrass areas.

“A flood of this magnitude early in the wet season coincides with the end of cane crushing season, when fertilisers and pesticides have typically been applied to paddocks. This means there is a greater risk of runoff from paddocks,” he said.

“Many landholders are making extraordinary efforts to ensure they are minimising their off-farm losses of fertilisers and pesticides, while also undertaking local paddock scale water quality monitoring programs to understand runoff from their catchments.

“We need to support the farmers to continue these programs coupled with more water quality monitoring, especially when these events could become more frequent.”

Dr Lewis said a greater understanding of how sediments and nutrients travel from the land to the outer reefs is required to document exposure further offshore.

“Past monitoring on outer reefs indicates the presence of elevated nutrients linked to terrestrial runoff, which is supported by our satellite observations,” he said.

“But the current flood monitoring only samples waters in inshore areas, it doesn’t sample the outer reefs, and this is critical for understanding the impacts of terrestrial runoff on reefs further offshore.

“There needs to be more targeted monitoring to understand the connection between the catchments to the middle and outer reefs to fully understand the extent and impact of land-based runoff.”

Jane Waterhouse said understanding water quality is paramount for the long-term protection of marine ecosystems.

“It seems there’s no relief for the reef. This could be a new pattern emerging under climate change with relatively dry periods of mass coral bleaching events interwoven with periods of extensive flood events, with little to no time for marine ecosystems to recover in between disturbances.”

Marine heatwaves, cyclones, and flood plumes are weather events expected to escalate with the intensification of climate change.

“These pressures compound, hindering the recovery of ecosystems already grappling with prior disturbances, such as coral bleaching. Good water quality is essential for the recovery of reefs,” she said.

“The cumulative impact is unprecedented and deeply concerning. The true extent of the long-term impact remains largely unknown.”

Water quality and seagrass monitoring is part of Marine Monitoring Program, coordinated by the Great Barrier Reef Marine Park Authority, in partnership with JCU TropWATER, Cape York Water Monitoring Partnership, Australian Institute of Marine Science and the University of Queensland.

Link to images here.

Traditional Owners study ancient marine ecosystem as it spawns the next generation of corals

The Great Barrier Reef stands as one of the world’s oldest natural wonders, with First Nations people living alongside the evolution of this vast coral ecosystem for millennia.

This week, as the Great Barrier Reef births the new generation of corals in the annual mass spawning event, Traditional Owners are studying this ancient marine ecosystem with scientists – observing the spawning process from fertilisation to the transformation of larvae into baby corals.

The seven-day ‘Spawning School’ is led by James Cook University’s TropWATER under the Cairns-Port Douglas Reef Hub in collaboration with Reef Recruits and local Land & Sea Rangers, funded by the partnership between the Australian Government’s Reef Trust and the Great Barrier Reef Foundation.

“We as First Nations people have co-existed with this complex ecosystem for thousands of years, and with that comes a deep connection with the Great Barrier Reef,” said Stirling King, Gunggandji-Mandingalbay Yidinji Land and Sea Ranger.

“We are excited, as Rangers, to connect our Elders and community members with coral spawning and share our passion for this special time of year on the Reef.”

Project Lead JCU TropWATER’S Dr Katie Chartrand said understanding coral spawning processes and building capacity for Traditional Owners was a practical way for communities to engage and explore the science and culture of this annual event.

“This project is driven by the need to integrate Indigenous perspectives with western science to understand, preserve, and navigate the challenges facing the Reef,” she said.

“Over the next week, our focus will be on the intricacies of the spawning process. We’ll be equipping rangers with the essential skills for active involvement in reef recovery techniques.

“The Spawning School project aims to enhance education and facilitate two-way knowledge exchange for future Reef restoration programs.”

Mass coral spawning serves as the reef’s natural recovery time, replenishing reefs in a once-a-year event. However, given that only a fraction of corals naturally survives the larval stage, there is a need to explore ways to harness spawning outputs to help expedite the recovery of damaged reefs.

Dr Chartrand said the corals, collected from healthy reefs on Yirrganydji sea Country, will spawn in the JCU Eduquarium, “here the baby corals will then be raised in the lab and settled on devices with an opportunity for Rangers to participate in research led by Reef Recruits.”

Reef Recruits ecologist Dr Kerry Cameron says incorporating a research experiment into the Spawning School program offers additional learning opportunities for Rangers.

“Coral spawning, a rare event, is the focus of the Spawning School. It’s an opportunity to gain fresh insights into larval behaviour. We explore spawning, conduct experiments on larval readiness to settle, and provide rangers a platform to actively contribute to discussions on research findings.”

Coral spawning and the work to rear the larvae will also be shared back into community through an Indigenous-led production company Reef Cast. Malachi Johnson, host of Reef Cast, will drive communication of this project to communities.

“This collaboration between Traditional Owners and researchers is significant, because working together in all areas of research is key to sustainable custodianship of the Reef. Walking together, not in front or behind but side by side in solidarity,” he said.

The Cairns-Port Douglas Reef Hub is funded by the partnership between the Australian Government’s Reef Trust and the Great Barrier Reef Foundation. The Hub is coordinated by TropWATER at James Cook University and enabled by the partnership’s Community Reef Protection and Traditional Owner Reef Protection components, and the Reef Restoration and Adaptation Program with a network of local partners.

Scientists take students beyond the classroom in unique opportunity

This year, TropWATER scientists provided high school students at Newman Catholic College in Cairns with a unique opportunity to advance their scientific knowledge beyond the classroom, inspiring a new generation of environmentally conscious leaders.

Under the scientist’s guidance, the Reef Guardian class has taken an active role in rehabilitating damaged seagrass meadows in the Cairns Inlet, while also conducting seagrass monitoring quadrat studies at Green Island.

TropWATER’s marine biologist Evie Furness said the initiative provided students with valuable insights into conservation and the possibilities of marine biology as a career.

“We were able to teach students about techniques for seagrass restoration while working alongside our scientists and Indigenous Sea rangers in one of our restoration projects,” she said.

“We’ve been able to show students how these underwater habitats are vital for marine life diversity and how they can play a significant role in maintaining the health of the Great Barrier Reef.”

The students actively participated in preparing harvested seagrass samples for planting, helping to the revitalise damaged seagrass meadows and promote a healthier marine environment.

In addition to their restoration efforts, the Reef Guardian class engaged in seagrass monitoring quadrat studies at Green Island, a crucial feeding habitat for green sea turtles.

“On Green Island, we showed the students about the value of monitoring, why ecosystems need to be monitored, and what’s involved in this. They used quadrats, identification guides, and waterproof data sheets to collect valuable data on seagrass health and biodiversity,” she said.

Matt Radburnd, Newman College Science teacher, said the collected data not only enhances students’ understanding of marine ecosystems but also provides them with a head start for their studies in senior Biology and Marine Science QCAA courses.

“These experiential learning opportunities play an important role in shaping the future environmental leaders of our community,” he said.

“We extend our heartfelt gratitude to the scientists. Through this unique partnership, our students have not only gained invaluable scientific knowledge and skills, but have also developed a deep sense of appreciation for the natural world.”

Seagrass recovery in Great Sandy Marine Park

Widespread regrowth of seagrass has been reported within the Great Sandy Marine Park, following multiple flood events in early 2022 that led to a devastating loss of seagrass meadows.

Researchers from James Cook University (JCU) TropWATER, in collaboration with Queensland Department of Environment & Science and marine park rangers from Queensland Parks and Wildlife Service (QPWS), have been conducting surveys to monitor the loss and regrowth of seagrass meadows since the floods.

JCU TropWATER’s Associate Professor Michael Rasheed said the most recent results show widespread recovery of seagrass, in many sections of the marine park.

“We have seen big increases in the deepwater seagrasses in the middle of Hervey Bay as well as substantial expansion of in intertidal seagrasses in the Great Sandy Strait that were devastated following the floods of 2022,” he said.

“This is a reassuring outcome, but there is still uncertainty of seagrass meadows’ resilience, and if it can sustain this recovery in the long-term.”

Senior Ranger Daniel Clifton said the Great Sandy Marine Park was a major hotspot for dugongs in Queensland, meaning the overall health of the marine ecosystem played a crucial role in sustaining populations of these threatened animals.

“The Great Sandy Marine Park’s seagrass meadows are a critical part of the marine ecosystem to support local sea turtle and dugong populations,” Ranger Clifton said.

“By monitoring the abundance of seagrass across the park, we get a better picture of the health of the wider marine ecosystem in the area.”

Impact on dugongs and resilience of seagrass meadows

While the recovery is promising, recent JCU TropWATER dugong surveys reveal that the initial loss of seagrass meadows took a significant toll on dugong populations in the region.

JCU TropWATER dugong researcher Dr Chris Cleguer, who conducted dugong population aerial surveys following the floods, said there was a reduction in dugong numbers in Hervey Bay in November 2022.

“Seagrass habitats were greatly reduced quickly following the floods, and the dugongs in the area would have had little food in these months,” he said.

“It’s highly likely that some dugongs would have died from starvation, while others would have moved to reach deeper seagrasses in the middle of Hervey Bay or simply leave the area to  other importance seagrass habitats such as Gladstone in search of food.

“The case of Hervey Bay serves as a warning of what may continue to occur under future climate conditions, it underscores the urgency in preserving and understanding seagrass habitats, particularly the deeper water ones, as herbivores like dugongs may increasingly rely on them.”

To understand the seagrass meadows’ resilience, JCU TropWATER and QPWS will continue to monitor the health of seagrass in the area including examining light availability within the Great Sandy Strait, a herbivory exclusion study looking at how marine life feeding on seagrass impacts recovery, and seagrass seed bank availability.

“We are really interested in the health of seagrass meadow’s seed bank, which is the repository of seeds in the sediment that influences the ability of the meadows to recover and remain healthy in the event of further impacts,” said Associate Professor Michael Rasheed.

“Understanding the health of the seed bank is key to figuring out how resilient these meadows are against future pressures, such as intense feeding from dugongs and the possibility of more flooding in the years ahead.

“The reality of climate change means we need to continue to regularly monitor these seagrass meadows and to develop potential restoration methods. This will allow us to quickly respond to damaged or lost meadows to ensure we have these important ecosystems into the future.”

Research and collaboration for future resilience

With a team of leading scientists specialising in the expansive realm of tropical aquatic ecosystems, spanning both marine and freshwater domains, TropWATER takes a pivotal role in ensuring that its research not only informs but also contributes practically to resilient and sustainable solutions for aquatic ecosystems.

TropWATER has leveraged its expertise in dugongs, seagrass, and water quality, as well as strong collaboration with DES/QPWS, to provide a holistic pathway in ensuring the long-term preservation of these crucial ecosystems.

Recognising the uncertainty surrounding the resilience of seagrass meadows to future impacts, scientists emphasise the need to continue monitoring, research, and investigate potential restoration methods.

TropWATER is renowned for addressing environmental challenges for a diverse range of stakeholders, including industry, First Nations peoples, governments, communities, and policymakers.

Navigating water security, ecology, and development in Northern Australia

JCU TropWATER researchers are investigating the challenges associated with developing water security in Northern Australia, particularly in regions celebrated for their ecological richness and diversity.

Under the Water Security for Northern Australia program, scientists from JCU TropWATER, Charles Darwin University and CQ University are examining targeted catchments from Western Australia to eastern Queensland, including the Gilbert River, Lower Fitzroy River, Daly River, and Ord River irrigation area.

JCU TropWATER Director Professor Damien Burrows said the amount of water needed for Australia’s agriculture will continue to grow along with the global population, and this has placed inevitable pressure on securing water from natural waterways.

“As we explore water security in Northern Australia, there’s a critical need to find a balance between meeting human needs and preserving the environment, while understanding the limitations to potential development,” he said.

“Science is critical in guiding these development decisions, particularly given the arid and challenging climate conditions of Northern Australia, coupled with few suitable catchments.

“Our challenge is to maximise these constrained opportunities through rigorous scientific measures, ensuring environmental preservation amid economic aspirations.”

Unravelling the impact of development on Northern Australia’s ecological values

With nearly half of Australia’s total land area and only 5% of the population, coupled with ample rainfall and abundant water resources, Northern Australia is a favourable region for water security for agricultural expansion.

Yet, while Northern Australia is recognised for its economic potential, it’s also ecologically important, renowned for vast, biodiverse aquatic ecosystems. Beyond this, the landscape also holds high cultural importance for Indigenous communities, who have maintained a deep connection with the land for generations.

TropWATER’s Dr Paula Cartwright said the region boasts countless wetlands with natural wet-dry seasonal cycles, housing a unique collection of fauna and flora that only exist under these conditions.

“The region features diverse ecosystems, where freshwater systems seamlessly connect to vital mangrove habitats and other marine ecosystems, allowing for biodiversity to thrive,” she said.

“The area’s natural wet-dry cycles also play a pivotal role in supporting the survival of distinctive species, such as the sawfish and global migratory birds.”

Dr Cartwright said that without environmental research, building infrastructure to secure water could disrupt water quality and the natural flow essential to ecosystems in both wet and dry seasons.

“Interfering with natural waterways can have far-reaching consequences, affecting migration patterns, sediment movement, nutrient cycling, and temperature. These disruptions, in turn, could have cascading effects on the diverse fauna and flora, including vulnerable species like the sawfish,” she said.

“Understanding the risks and implementing sustainable water management solutions means we can mitigate these disruptions and preserve the ecological integrity of water systems.”

A case study: a close look at the Queensland’s Gilbert River catchment

One region TropWATER scientists are investigating is Queensland’s Gilbert River catchment. It has been highlighted as containing critical habitats for aquatic species as well as seasonal watering holes for many terrestrial species.

Freshwater sawfish are a major focus for scientists in this area, with the species listed as endangered under state and federal legislation. Prawns and barramundi, both significant recreational and commercial industries, also rely on the water connectivity between salt and freshwater systems in this catchment.

Dr Cartwright said the team would survey across floodplains, rivers, and tributaries, to identify the diversity of aquatic and terrestrial species, using advanced technologies like eDNA sampling, sound bars, and in-water camera surveys.

“We’ll also use long-term satellite data to map waterhole fluctuations through wet and dry seasons and hydrology data to better understand groundwater/surface water interactions across the system,” she said.

“Together, an understanding of species distribution and their interaction through food webs, along with mapping of the interannual variability in waterholes, will allow us to pinpoint what is most sensitive to disruption of seasonal waterflows.”

“This helps identify areas at high ecological risk and those that can withstand certain levels of development without causing significant environmental harm.”

What next, in 2024?

In 2024, the Water Security for Northern Australia program builds upon the groundwork laid in 2023, conducting comprehensive desktop analyses and fieldwork in the Gilbert, Ord, Fitzroy, and Daly River catchments.

Post-wet season, researchers will address data gaps and explore the impact of varying wet season rainfall on species distribution and waterhole ecology.

The three-year program will continue to unravel the complexities of water security, ecology, and development to allow sustainable development.

Connecting farmers to science: how paddock-scale data is driving change

As environmental challenges escalate, the need for cane farmers to help improve water quality continues to grow to build the resilience of ecosystems, like the Great Barrier Reef.

But how do you bring science to farmers in a way that matters, in a way that empowers collective action to meet the needs of the environment while also meeting the needs of farming?

Across the Great Barrier Reef catchment, scientists and cane farm extension officers are enhancing paddock-scale water quality monitoring projects to strengthen the crucial link between water quality science and sustainable agriculture.

The James Cook University TropWATER project unites ten water quality monitoring projects – spanning the Wet Tropics, the Burdekin, and Mackay Whitsunday regions – to collectively improve the data collection and communication of water quality science in farming communities.

This initiative harnesses the strong rapport between on-ground extension officers and farmers. It focuses on the potential impact that paddock-scale and sub-catchment scale water quality data has in directly empowering farmers in the transition to improved agricultural practices.

The TropWATER project, as well as the ten water quality monitoring projects, are funded by the partnership between the Australian Government’s Reef Trust and the Great Barrier Reef Foundation, under the Regional Water Quality Program (Regional Programs – Great Barrier Reef Foundation).

In this article, we explore the intricacies of balancing agriculture and good water quality, and the role this TropWATER project has in bolstering efforts of those on the ground working with farmers.

Why do sugarcane farms matter in the Great Barrier Reef catchment?

Australia’s agriculture industry, including sugarcane, plays a significant role in our economy and global food security. It supports the livelihoods of thousands of Australians and is at the heart of many small north Queensland communities.

About 90% of Australia’s sugarcane is produced in Queensland. Many of these cane farms stretch along the narrow coastal plains adjacent to the Great Barrier Reef, knitted among freshwater and inshore marine ecosystems. Given this close connection, managing the farming business and the protection of the environment is an essential balance in agriculture practices.

Cane extension organisations have supported farmers in adopting improved land management practices that has co-benefits for both farm production, profitability and preserving local ecosystems.

The connection between farmers and extension officers is proving vital in communicating robust water quality science directly to farmers – helping more farmers transition to environmentally sustainable and more efficient farming systems.

How does agricultural runoff impact freshwater and marine ecosystems, including the Great Barrier Reef?

Water quality issues impacting marine and freshwater ecosystems arise from a combination of factors, including urban development, climate change, and agriculture. Within this, intensive farming is recognised as a major contributor.

In the sugarcane industry, applying fertiliser (nitrogen, phosphorus, potassium and other micro-nutrients) is needed to enhance soil fertility, meet crop nutrient demands and promote healthy cane growth. Pesticides are also used to control and kill targeted pests, like the cane grub and grasses, vines and broadleaf weeds.

TropWATER Senior Researcher Dr Stephen Lewis said while these products were essential in modern farming systems, decades of research highlight the connection between farm runoff and its impact on water quality in both freshwater and inshore marine ecosystems.

“Heavy rainfall and intense irrigation can transport nitrogen and phosphorus fertilisers and pesticides off the paddock quickly and into drainage systems and waterways,” he said.

While inshore areas are commonly more turbid and nutrient-rich environments compared to offshore marine ecosystems, excess sediment and nutrients from runoff can reduce water clarity and exacerbate inshore nutrient levels. This causes phytoplankton blooms, persistent macroalgae outbreaks on inshore coral reefs and a loss of seagrass area and abundance.

“These elevated sediment and nutrient levels can drive water quality down, impacting the resilience of coral and seagrass communities to recover from major disturbances, like cyclones, floods and coral bleaching,” he said.

“The highest direct risk of poor water quality is to local waterways, freshwater wetlands, and inshore seagrass meadows and coral reefs close to the coastline.”

Every farm has its challenges in mitigating this runoff. Understanding those challenges is critical in making impactful changes to the farming system.

How can paddock-scale water quality monitoring drive improved farming practices?

Agricultural systems are complex. Each farm has a unique set of challenges that must be carefully managed under the variability of different target pests, soil type and rainfall.

Given each farm is unique, monitoring water quality allows farmers to compare different farming practices to better understand the amount of products lost from their farm and what strategies are most effective in mitigating this loss.

Dr Aaron Davis, TropWATER senior scientist and project lead on multiple water quality monitoring projects, said there were many farmers making great strides in improving their land management practices across the Great Barrier Reef catchment.

“Farmers care greatly about their local environments, but some farmers can be unsure about the role agriculture plays in declining water quality and how fertilisers or pesticides on their paddock can run into waterways,” he said.

“They also can be unsure if and what management practices can actually make a difference in improving water quality without decreasing the production of their farming business.”

Dr Davis says robust paddock-scale water quality data helps farmers confidently understand their irrigation, fertiliser, pesticide and sediment surface losses.

“Showing farmers paddock-scale data is empowering them to make decisions based on what is relevant to their farm – and farmers can see these direct results as they adjust their practices.”


Connecting monitoring efforts across the Great Barrier Reef

The GBRF and JCU TropWATER initiative connects multiple on-ground projects from different Great Barrier Reef catchments, aiming to help build farmers’ trust in water quality science to ultimately facilitate change in achieving a balanced farming system.

These on-ground projects focus on different strategies to improve farming practices and reduce runoff, including optimising irrigation efficiency, enhancing nutrient removal through water retention, refining fertiliser and mill mud application rates and strategies, and promoting responsible pesticide management.

TropWATER researcher Dr Zoe Bainbridge said the collaboration takes a distinctive approach that integrates scientific expertise from leading water quality researchers with strategies from science communication specialists.

“Our team has two decades of water quality science experience that span from the paddock to marine environments. We understand the water quality issues associated with multiple land uses, including the paddock-scale, and have applied water quality monitoring to show the benefits of various management practices,” she said.

“We’ve matched our scientific expertise with strategic communications, with a big focus on tackling communication barriers in water quality science. Our goal is to arm extension officers with tools and strategies to help overcome those challenges, including developing consistent messaging to address mixed messages and misinformation.”

In the last year, the project has hosted various workshops and training programs, provided critical resources to extension officers, developed legacy documents in technical guidance, and provided strategic communications support.

“TropWATER’s support has been a resounding success, with real legacy impact and a sustainable future for both farmers and the environment,” said Carolyn Trewin of the Great Barrier Reef Foundation.

“Projects have provided overwhelmingly positive feedback to the Foundation about their involvement, and we are confident that water quality monitoring activities are more robust, with effective engagement and communication strategies because of this initiative.”

It’s hoped the project can expand to continue to break down communication barriers in water quality science, ensure robust data are collected to drive a sustainable future for both farmers and the environment, and expand the collective efforts of extension staff and farmers in improving water quality across the Great Barrier Reef catchment.

This project is delivered in collaboration with specialists from the CSIRO, UQ’s Reef Catchments Science Partnership and AgriTech Solutions. Water quality projects are led by Farmacist, Sugar Research Australia, Burdekin Bowen Integrated Floodplain Management Advisory Committee (BBIFMAC), Catchment Solutions, LiquaForce, Herbert Cane Productivity Services, TropWATER and Terrain NRM.

Long-term decline in dugong populations confirmed along Great Barrier Reef

A new report from James Cook University (JCU) TropWATER reveals a long-term decline in dugong populations along the Great Barrier Reef, spanning from Mission Beach to Bundaberg, and Hervey Bay in the Great Sandy Strait.

Aerial surveys conducted in 2022 confirm that this declining trend has persisted for almost two decades, despite Australia’s renowned global status as the host of the world’s largest population of these vulnerable marine mammals.

Released this week, the 2022 Dugong Aerial Survey: Mission Beach to Moreton Bay report is part of a series of aerial surveys conducted every five years to monitor the distribution and abundance of dugongs along Queensland’s coast. The 2022 survey focused on the Mission Beach to Moreton Bay region, with surveys from Cape York to Cairns set to commence next week.

Lead dugong researcher, JCU TropWATER’s Dr Chris Cleguer said the report shows a clear declining trend since 2005, with an estimated annual population decline of 2.3% from Mission Beach to Bundaberg.

“We observed a decline in overall dugong numbers, with the area of most concern being the southern section of the Great Barrier Reef from the Whitsundays to Bundaberg,” he said.

“Alarmingly, we observed very few calves in this region, and only two mother-calf pairs spotted in the Gladstone area.

“Our report reinforces the urgency in addressing threats to dugongs.”

While the overall population is declining, the 2022 aerial survey confirmed areas of high dugong numbers in specific regions, including Hinchinbrook, the Townsville area, and Shoalwater Bay.

The dugong aerial surveys in the Great Barrier Reef are one of the most critical Reef monitoring projects funded by the partnership between the Australian Government’s Reef Trust and the Great Barrier Reef Foundation. The surveys in Queensland’s southern bays, Hervey Bay and Moreton Bay, are funded by the Department of Climate Change, Energy, the Environment and Water (DCCEEW). The initiative is supported by the National Environmental Science Program.

Minister for the Environment and Water Tanya Plibersek MP said the Government is committed to putting a stop to biodiversity decline.

“This research, sadly, draws a clear picture of what we already know – that more needs to be done to address species decline in Australia, including on the Great Barrier Reef,” she said.

“I want to see this majestic creature on a path to recovery.”

“That’s why we’re restoring important blue carbon ecosystems like sea grass which dugongs call home, and investing $1.2 billion to protect the Great Barrier Reef.

“We’re also supporting the Queensland Government to phase out gillnets in the Great Barrier Reef, which are a key threat to dugong populations.”

Great Barrier Reef Foundation Integrated Monitoring and Reporting Director Charlie Morgan said the Great Barrier Reef supports one of the world’s largest dugong populations.

“The condition and behaviour of individual marine species such as dugongs can tell us a lot about ecosystem health as a whole so the news that this iconic marine animals’ numbers are declining is another sign that the Reef needs our help to protect it from the growing impacts of climate change,” Ms Morgan said.

Hervey Bay, located south of the Great Barrier Reef, showed the most significant estimated rate of population decline at 5.7% per year between 2005 and 2022. These findings are linked to back-to-back flood events in early 2022, resulting in extensive seagrass loss and depriving dugongs of their primary food source.

“Seagrass habitats are very sensitive to extreme weather events like cyclones and flooding, and often healthy meadows can deteriorate within a matter of weeks or months following an event,” Dr Cleguer said.

“It’s highly likely that some dugongs would have died from starvation, while others would have moved away to habitats near Gladstone in search of food.

“We found the dugongs that did stay found refuge right in the heart of Hervey Bay, where pockets of deeper seagrass were still holding out.

“The case of Hervey Bay serves as a warning of what may continue to occur under future climate conditions, it underscores the urgency in preserving and understanding seagrass habitats, particularly the deeper water ones.”

Following the results from Cleguer et al.’s report, the Department of Climate Change, Energy, the Environment and Water (DCCEEW) have provided funding to re-survey Hervey Bay to assess the recovery of dugongs in this area.

Seagrass loss
Dugong declines in Hervey Bay can are linked to back-to-back flood events in early 2022, resulting in extensive seagrass loss and depriving dugongs of their primary food source.

JCU TropWATER researchers consulted with Traditional Owners along the Queensland coast. The report discusses how new technologies could be used by Indigenous rangers in sea country management.

“This consultation confirmed that Traditional Owners are very keen to be informed on the results of the surveys as well as opportunities to be actively involved in future monitoring,” Dr Cleguer said.

“By training up Traditional Owners on sea country we could have more regular and finer scale monitoring. This could help to detect changes in population size to allow managers to intervene quicker.”

Director of JCU TropWATER, and leader of the National Environment Science Program Marine and Coastal Hub, Professor Damien Burrows, highlighted TropWATER’s renowned expertise in seagrass and dugong research, with a strong commitment to preserving these vital ecosystems and megafauna.

“We have over four decades of extensive research covering both dugongs and seagrass habitats, spanning from southern Queensland to Shark Bay in Western Australia,” he said.

“Our researchers are exploring innovative technologies such as drones, AI, body condition assessments, e-DNA and genomics approaches to enhance our monitoring and advance our research of dugongs and seagrass, including their interconnections.

“We are also actively collaborating with Traditional Owners on sea country, providing communities with the necessary tools to monitor both dugongs and seagrass effectively.”



Media enquiries: JCU TropWATER Media, Molly McShane 0448 015 278

Pix and video available:

Further images are available on request. These include seagrass surveys at Hervey Bay, dugong monitoring at particular sites, and profile images of Dr Chris Cleguer. Please contact Molly McShane for further information. 0448 015 278

The report :

Large-scale seagrass restoration takes root in Tropical Australia

Tropical Australia’s first large-scale seagrass restoration project begins this week in Cairns and Mourilyan, aiming to replenish more than 400 hectares of seagrass habitat devasted by cyclones and La Nina weather events more than a decade ago.

Led by James Cook University’s TropWATER, the initiative will see scientists and volunteers planting thousands of seagrass fragments and sowing more than half a million seeds over the next four years.

The project is a collaboration with four Traditional Owner groups, OzFish Unlimited and local community groups, with funding support from BHP’s Blue Carbon Grants program.

JCU TropWATER’s Associate Professor Michael Rasheed, who leads the team, said the project was built on years of rigorous research and trials.

“This is the first time seagrass restoration has been attempted at this scale in tropical Australia. We’ll be working in partnership with community in partnership with communities and leading researchers in the field.

“For more than a decade, the loss of these seagrass meadows has set off a ripple effect, robbing these ecosystems of their remarkable benefits – as a food source for dugongs and green turtles, and as essential nurseries for prawns and fish.

“It’s critical these habitats are restored, not just for the sake of the marine life they sustain, but for the resilience of our coastal communities.”

Seagrasses are coastal marine powerhouses, capable of capturing carbon from the atmosphere up to 35 times faster than tropical rainforests.

Along with re-establishing the seagrass meadows the team will measure these “blue carbon” storage gains, and will monitor the return of fish.

The initiative brings together Traditional Owner partner groups, including Gimuy Walubara Yidinji, Dawul Wuru, Goondoi and Mandubarra, in safeguarding their Sea Country estates.

The donor seagrass for the program comes from Gimuy Walubara Yidinji country in Cairns.

“We’re pleased to extend assistance and share our resources with our neighbouring communities, including Mandubarra and Goondoi in Mamu country to our south,” Gimuy Walubara Yidinji Elder Gudju Gudju said.

“This collaboration will help restore their lost seagrasses while enhancing our understanding of safeguarding our own,” he said.

“Our Rangers are building strong relationships with JCU scientists and creating valuable opportunities for mutual learning. These partnerships empower our community, rangers, and scientists to exchange knowledge. They foster the protection of our remarkable marine ecosystem for generations to come.”

The team needs help from the community for the project to succeed. OzFish Unlimited’s Dr Geoff Collins is in charge of coordinating community and volunteer engagement for the project.

“Preparing seagrass shoots for deployment takes a lot of time and we value the contribution our volunteers have made to this program to date,” Dr Collins said.

“As we continue to expand this work there’ll be an increasing role for volunteers to help improve seagrass meadows, which are important for the health of our coastal fish stocks.

“We’ll be posting regular notifications and events to let the community know when you can come down to the Marina in Cairns, or the Mourilyan Harbour boat ramp, to help prepare the seagrasses for sowing out on site during September.”

The team will restore five hectares of meadows wiped out a decade ago. They will also work to speed the recovery of 425 hectares of meadows that are struggling to recover from cyclone damage and consecutive years of heavy wet season impacts leading up to 2011.

Associate Professor Rasheed said seagrass habitats are interconnected with the health of the Great Barrier Reef, and the loss of meadows can have cascading effects on the entire Reef ecosystem.

“Climate change is causing more frequent and widespread impacts on seagrass meadows, and we need to take steps to future-proof these ecosystems,” he said.

“This project will show effective restoration methods that can be used throughout tropical Australia and a blueprint for measuring their effectiveness at combating climate change and we’re excited to get cracking on the work this week.”

A gateway to understanding manta rays in the central Great Barrier Reef

James Cook University scientists are studying a previously unknown manta ray aggregation at Holbourne Island – capturing photographs of the mantas’ distinct markings and deploying satellite and acoustic tracking tags.

It’s the first satellite and acoustic tag to be deployed on a manta ray in the central area of the Great Barrier Reef, uncovering valuable insights on how mantas travel and connect with neighbouring habitats.

Funded by North Queensland Bulk Ports Corporation (NQBP), the JCU team will continue to work with Dr Adam Barnett and Ingo Miller from Biopixel Oceans Foundation (BOF) to uncover critical information about these elusive creatures.

The data from the tracking tags will feed into BioTracker and into a broader national research program ‘Project Manta’, which seeks to uncover manta behaviour, movement patterns and population dynamics in Australia.

The manta aggregation discovery was first made by Tony and Avril Ayling, experienced reef monitors and JCU alumni.

Researching the elusive gentle giants

Manta rays, known as the world’s largest rays, boast impressive wing spans of up to 7 meters and are often referred to as the gentle giants of the ocean.

Each manta ray has distinct markings on their underbelly, similar to a fingerprint. By capturing images of mantas’ underbelly, researchers can track individual mantas these unique identifiers.

Lead scientist of the JCU-NQBP coral monitoring program, JCU’s Dr Katie Chartrand, said with limited data on manta populations within the central Great Barrier Reef, the newly identified site offers a valuable opportunity to capture images of mantas and track population movements in the region.

“We know this manta aggregation at Holbourne Island is attributed to a cleaning station. This is where smaller fish species diligently remove dead skin, bacteria, and parasites from manta rays and other larger marine animals,” she said.

“These cleaning stations are fixed to where the cleaning fish set up shop, meaning we will be able to reliably document animals visiting over a long period of time.”

It’s the first satellite and acoustic tag to be deployed on a manta ray in the region, and will invaluable insight s on how mantas travel and connect with neighbouring habitats.

Research support research programs ‘Project Manta’ and ‘BioTracker’

Project Manta has over 1500 individuals recorded in the east coast database, with over 9000 photo-ID sightings. Through its comprehensive photo-ID sightings database and satellite and acoustic tracking tags, Project Manta will be able to fill key knowledge gaps about mantas in Australia.

BioTracker follows sharks and rays using satellite transmitters to learn more about movement and migration patterns, which helps to identify habitats key to their survival, their relationship with other marine animals, population dynamics, and their vulnerability to threats. A network of acoustic underwater receivers feedback additional information on finer-scale megafauna movements.

The Holbourne Island discovery, supported by the long-standing partnership between NQ Bulk Ports and JCU, enhances the research efforts of Project Manta and BioTracker.

NQBP’s has a long-standing marine monitoring partnership with JCU, with scientists undertaking extensive ambient marine environmental monitoring of water quality, coral and seagrass for more than two decades.

Surveying mangrove forests along the southern Great Barrier Reef coastline

Mangroves are nature’s blue carbon powerhouses – capable of capturing and storing significant amounts of carbon – making them a vital tool in mitigating the climate crisis.

They’re also biodiversity hotspots that provide essential breeding grounds for native fish, while stabilising coastline ecosystems and reducing erosion.

But the state of mangrove habitats along the Great Barrier Reef coastline is a growing concern, and until now, knowing if and where we can restore lost forests has remained unanswered.

Funded through Greening Australia’s Reef Aid program, as part of the Blue Carbon Initiative, a team of James Cook University TropWATER scientists have taken to the skies, conducting helicopter shoreline surveys from Cairns to Gladstone.

With a bird’s-eye view, the team assessed the health of these vital shoreline ecosystems, including both forest loss and gain and their continued threats. At the same time, they identified potential sites for restoration and registration as Carbon Projects under the Clean Energy Regulator’s recently released Tidal Restoration of Blue Carbon Ecosystems method.

Shoreline transformation: the condition of mangrove forests along the Great Barrier Reef coastline

Over 80,000 high-resolution geo-referenced photographs were captured during the surveys, providing a crucial baseline of the Great Barrier Reef shoreline condition and a profound insight into what’s being lost.

Lead JCU researcher Professor Norm Duke said the stretch of coastline, with its distinctive blend of wet and dry tropic climatic areas, had not been surveyed to this extent before and early results show vast damage.

“Our observations provide clear, unequivocal and quantifiable evidence of changes to this increasingly dynamic shoreline,” he said.

“We can see the impact of severe tropical cyclones that have battered the region over the past four decades. We can also see extensive shoreline tree loss from erosion, coupled with scouring erosion of salt pans, and retreat of terrestrial shorelines.

“These are thought to be widespread evidence of rising sea levels.”

Dr Duke said observations were consistent with local records of sea level rise over the last half century of at least 4mm per year.

“We believe these changes must be monitored on a regular basis so that we can both manage the impacts, improve the resilience of shoreline marine ecosystems, and guide effective adaptation to the inevitable altered coastal areas.”

Can we restore mangrove habitats along the Great Barrier Reef coastline?

While it’s possible to restore some parts of coastal shorelines, Dr Duke says it’s not the complete answer to the climate crisis for shorelines.

“This project is allowing us to identify locations for restoration of tidal wetland habitats and their capacity to sequester and store carbon – which could help reduce one of the key drivers of global climate change,” he said.

“But our assessments reveal forces at play are far more widespread and active, and simply planting mangroves is not the answer to the climate crisis.”

Dr Duke said there needs to be greater effort into building greater resilience into shorelines, including the repair of damaged areas, and targeted planning for coastal zones to adapt and retreat.

“The complexity of such a response cannot be underestimated, but if we don’t anticipate the inevitable and predictable changes coming our way, then we will be faced with one damaging shoreline disaster after another.”

“As a smart society, if we move quickly, we can be climate change entrepreneurs instead of its ignorant victims.”

Dr Duke said building resilience allows mangroves to migrate upland to survive. This includes providing supratidal buffer zones for the upland migration of mangrove seedlings by controlling things like fires along shoreline edges, removal of smothering weeds, eradication of routing feral pigs, combined with targeted mitigation like the removal of non-essential constructed bund barriers.

Greening Australia’s Director of Reef Aid Dr Lynise Wearne said the project is an exciting opportunity to understand the priorities and opportunities for coastal restoration across the Reef Catchments as Greening Australia pioneers innovative nature-based solutions that benefit communities, economies and the environment.

The shoreline surveys were conducted in May 2023, and scientists will produce a detailed report later this year.


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