Each year, we celebrate the International Day of Women and Girls in Science (11 February) to acknowledge the contributions of the many women monitoring, researching, restoring, and protecting tropical ecosystems. We spoke with seven TropWATER scientists – with expertise spanning water quality, seagrass ecology, and marine megafauna – about their experiences, careers, and challenges they have faced as women working in science. Read on to learn more about Dr Shelley Templeman , Carissa, Reason , Dr Emily Webster , Jane Waterhouse , Professor Helene Marsh , Dr Jane Mellors , and Megan Proctor . Dr Shelley Templeman Dr Shelley Templeman’s work focuses on monitoring and understanding how ecosystem drivers influence aquatic ecology. This includes assessing water, sediment, macroinvertebrates, and vegetation along with climate and land use information, and running regular training courses for industry, government, NRM groups, Indigenous Rangers, schools, and community groups. Throughout my career I have worked with some amazing people (within the scientific and local communities) and their knowledge sharing has helped me become the scientist I am today. What led you to a career in science? Curiosity – I spent my childhood asking my parents “but why?” When my parents couldn’t answer the questions, I went to books (this pre-dated the internet). When they couldn’t help, I tried working it out for myself and kept going until I am where I am today (and still asking “why?”). What’s the best part of your job? The unpredictability of my career is the best part and because of that, I have had the opportunity to work in so many incredibly beautiful locations that very few people have ever seen. I have worked from the equator (West Papua) to Antarctica, and remote locations across northern Australia. What are some of the challenges as a woman working in science? Science has made many improvements during my career but there are still some significant unconscious biases that exist. Sometimes this comes from community stakeholders who look behind you for a man as the project leader when you start a new program. Sometimes it is the perception that female scientists need more help to apply for new opportunities and are therefore expected to jump through more hoops to apply for these opportunities. Carissa Reason Carissa Reason manages statewide seagrass monitoring programs and researches seagrass ecology, biology, and physiology. Her work focuses on assessing ecological health, the impacts of human activities, and the effectiveness of restoration and mitigation efforts. What led you to a career in science? I grew up on a cattle/farming property in central Queensland and knew I would always need to have animals and nature as part of my workplace.  A Zoology degree at JCU in Cairns cemented that pathway and led me firstly into monitoring fisheries resources for the Queensland Government and then into seagrass monitoring for TropWATER. What’s the best part of your job? What I love most about my job is the mix of adventure and analysis. I get to visit stunning, remote places to assess seagrass, spending long days on boats out on the water and in helicopters doing aerial assessments and having unforgettable wildlife encounters. Then I come back to the office to process and report on the data and recharge before heading out on the next adventure. What are some of the challenges as a woman working in science? One of the biggest challenges for me has been balancing being a mum with the travel and workload that come with a career in science. Taking time away for parental leave creates gaps in professional development and missed opportunities, and catching up can feel daunting. Having a supportive team has made a huge difference, helping me stay connected and continue moving forward. Dr Emily Webster Dr Emily Webster’s research is focused on the spatial ecology of threatened marine megafauna, particularly sea turtles. She works closely with government and Traditional Owners and wants to know how future climate change may affect the habitats that turtles rely on so we can allocate resources for effective habitat protection. What led you to a career in science? When I started my undergraduate degree I experimented with the arts – music, philosophy, and languages – but I found my first-year biology lectures were the most compelling, challenging my worldview and my understanding of ethics, human behaviour and our relationship with nature. I was also captivated by fieldtrips to amazing places that most people will never have the opportunity to visit, and close encounters with wildlife. Now, I am deeply concerned about climate change and the trajectory of our planet and want to contribute to positive environmental change.   What’s the best part of your job? Through my work I’m connected with people who are passionate, driven, conscientious, and deeply connected to nature. I love that my job is to be inquisitive and learn as much as I can. What are some of the challenges as a woman working in science? I have found it challenging to develop the confidence to speak out in a room of more qualified people or do things differently in an established system. Self-promotion and self-advocacy don’t come naturally to me either. I’m curious about how other women navigate career interruptions and keep up competitive grant and publication profiles while maintaining a healthy work-life balance. Jane Waterhouse Jane Waterhouse translates science for water quality management, from the catchment to the reef. Since 1998, she has been involved in many projects requiring a synthesis of the latest science to help managers make decisions. Jane has led the inshore water quality monitoring component of the Marine Monitoring Program since 2016. What led you to a career in science? I am passionate about marine environments – I have always loved spending days at the beach or out on the water and have always wanted to be a part of the protection and maintenance of the incredible values of these areas. I especially love the coastal and inshore areas which are so diverse, accessible, and beautiful, and enjoy learning more about their processes and management solutions as part of my job; I feel very fortunate. What’s the best part of your job? I have had the benefit of working with many incredibly clever, kind, and generous people who are genuinely making a difference to the way the Great Barrier Reef and water quality specifically is understood and is managed, and how improvements can be delivered. That keeps me going. For me, maintaining working relationships and networks has been critical to having an interesting and successful career, as well as having a mix of tasks – there is never a dull moment! What are some of the challenges as a woman working in science? I have been fortunate to have a very positive working environment. I made the decision to maintain a casual role early on to ensure I had flexible work hours to enable me to support my young family and choose projects that are of most interest to me; that has made a big difference. It was a potential risk to having an ongoing career in science – and realise it’s not an option that everyone can choose, so I am grateful that it’s worked out. Professor Helene Marsh Professor Helene Marsh is officially retired but remains very busy as a research leader and dugong expert. She currently leads the Threatened and Migratory Species and Threatened Ecological Communities initiative in the National Environmental Science Program, and continues to supervise students, deliver specialist lectures, and advise international agencies on dugong research. What led you to a career in science? I started my science degree at the University of Queensland with the intention of becoming a neuroscientist. I was fortunate to have the opportunity to undertake an independent psychology research project in my first year. I spent far too much time on this project, even though it wasn’t worth many marks. By the end of first year, I knew I didn’t want to be a neuroscientist, but I had discovered that I absolutely loved doing independent research. From then on, I was hooked and took every possible opportunity to do research projects as part of my degree. I am now a strong advocate for giving undergraduate students the opportunity to undertake research. What’s the best part of working in science? Making a difference. Discovering new knowledge, advising policymakers (I have provided advice to 14 countries), supporting research students (I have supervised more than 60 PhD candidates to completion), meeting inspiring people, and travelling to fascinating places – often countries within the dugong’s range. What are some of the challenges as a woman working in science? My biggest early challenge was bias against women in science. I still have a copy of a letter I received when I applied for my first job as a fisheries officer, stating that it was not government policy to employ women because fisheries officers had to drive boats, camp with fishermen, and carry heavy gear. I had my first child before finishing my PhD (not a great idea, despite having a very supportive partner) and worked part-time for several years while I had major child-rearing responsibilities. The greatest challenge then was being taken seriously as a scientist. Once I had a permanent position and my children were older, being a woman was no longer perceived as a problem. Nonetheless, there were many times when I was told I only obtained positions because I was a woman. Fortunately, such prejudices are now far less common. Dr Jane Mellors Dr Jane Mellors coordinates the field operations of a small team, collecting water samples during routine monitoring and from plumes during flood events between Gladstone and Cairns. Each trip involves boating, sample filtering in a field lab, submitting samples for analysis, downloading from instrumentation, and entering data. What led you to a career in science? As a child I was always poking around in rock pools, then in grade 10 I had this amazing biology teacher Dr Stren who was a marine biologist on sabbatical from the University of Palau. She was inspirational and most of our studies that year were on marine invertebrates – I was hooked. What’s the best part of your job? The best part is the diversity of locations/Sea Country I get to experience during the course of collecting the water samples, and the variety of activities involved getting all the samples to their end point. What are some of the challenges as a woman working in science? I have faced many challenges throughout my 42-year career in science. Early in my career, I encountered discriminatory attitudes toward women in the field. As my career progressed, balancing the demands of scientific work with family life – particularly when my child was young – required constant negotiation and resilience. Throughout, I also navigated the increasing competitiveness for research funding and the persistent pressure of the “publish or perish” culture. Megan Proctor Megan Proctor plans remote research trips and assists large-scale marine habitat mapping for coastal ecosystems across northern Australia. Some days, she’s flying around in a helicopter or dropping a camera off a boat, while many other days she is analysing images, creating flyers to share findings with local communities, and writing reports. What led you to a career in science? I grew up on the east coast in the US, spending summers at the beach and exploring tidal flats. I had a constant curiosity about the natural world and a special love of the ocean. As I got older, I was interested in the interaction between people and their environment and how science is communicated – I was convinced that if more people knew how amazing and important our ocean ecosystems are, then more people would take action to protect them. My first trip to Australia and diving on the Great Barrier Reef cemented my path and I’ve had the privilege of working across many different areas of marine science including science communication, tourism, and research. What’s the best part of your job? The best part of my job is being surrounded by incredibly passionate and intelligent people doing meaningful work, constantly learning new things and exploring remote regions of Australia. I have the great privilege of working with many Indigenous Rangers and Traditional Owners; being invited onto their Land and Sea Country and trusted with their knowledge and stories is a unique opportunity I will never take for granted. It is interesting, inspiring, and very fulfilling work! What are some of the challenges as a woman working in science? My early experiences showed me that higher levels of science were often dominated by men and characterised by competition, ego, and a work-work-work mentality. That environment didn’t appeal to me and at times I doubted if there was space for me to thrive in this field. Fortunately, I have had wonderful women mentors along my journey, and their example and encouragement led me to persevere and carve a path that suited me without compromising my values. I am grateful for the collaborative and supportive culture of my team at TropWATER that allows for personal and professional development, high-quality work, and a more manageable work-life balance.

The sun was gradually rising in shades of warm golds and vibrant oranges, casting a soft ethereal glow onto the water. While lost in the ocean's serene beauty, I noticed a dark shape moving in the water and coming to the surface. This was the moment I saw a dugong for the first time, on a boat at Cleveland Bay with researchers from JCU TropWATER. My name is Alessa. I am a Year 10 student attending St Catherine's Catholic College in Proserpine, Whitsundays. I was given the opportunity to complete my work experience with the Marine Megafauna team at James Cook University’s TropWATER, who are leaders in dugong research. Throughout the week, I was introduced to a wonderful and inspiring team and participated in a wide range of activities related to marine science and science communication – two fields which reflect my love for the ocean, writing, and the environment. In this blog, I would love to share a glimpse of my experiences from this unforgettable week. A 5am start to find dugongs with Sarah and Luisa Imagine waking up at 5am, 300 km from home, to embark on what would become an unforgettable boat trip to Cleveland Bay. I joined Dr Melanie Hamel, PhD student Sarah Landeo, and research assistant Luisa Schramm – in hope to encounter the majestic ‘sea cow’. For the very first time in my life, I watched dugongs swim in the ocean. I was astounded. Amazed. Speechless. Not only did I get to observe a dugong so close to the boat, but I got to see a mamma dugong and her baby calf. I was taken by surprise by how cute and graceful dugongs are – given they weigh more than 450kg. Dugongs are far heavier and far more elusive than they seem. They are the only marine mammal that is herbivorous – feeding almost entirely on seagrass. Dugongs can spend more than 15 hours a day feeding on hidden seagrass meadows, only surfacing occasionally for a breath. Because of this, they can be challenging to find. On the boat, while preparing the gear, Sarah explained how drone aerial surveys can detect dugongs in small areas. By flying the drone over Cleveland Bay, she was able to detect the dugongs and capture pictures while they surfaced for breath – assessing their health and overall condition. My job was to help record the data, such as the take-off and landing time of the drone, environmental factors such as water visibility, and observations on the dugong behaviour and physical condition. I even got to launch the drone a couple of times, using gloves to protect my hands from the churning propellers. The team taught me a lot about dugongs. Did you know that when dugongs feed, they create something known as a sediment plume? As dugongs pull seagrass from the seabed, sediments rise to the surface and create a cloudy patch that can indicate to scientists that there was, or may still be, a dugong feeding in the area. Dugongs also have tusks. These tusks are located from the top of their skull to their mouth but are only visible in mature males and extremely old females. Getting personal with turtles In the morning, I met with Dr Emily Webster to discuss her research on tracking turtles and dugongs. This project is working with Traditional Owners to understand where green turtles travel in the Whitsundays, and how the environment influences these behaviours. Turtle trackers are used by scientists to record the migration and behaviour of turtles over long distances. When the turtle surfaces for a breath, the tracker emits signals which are recorded by a satellite and downloaded for analysis. Today, it was my job to paint these trackers with a layer of an anti-fouling paint. This is to avoid unwanted growth of marine organisms that may interfere with the device’s performance. The trackers are then attached to the turtles with a strong, cement-like adhesive to prevent them from detaching during the tracking period.  In the afternoon, I went to JCU’s Turtle Health Research facility, Caraplace. Here, I was shown how 13 loggerhead turtles are cared for each day – including the most enjoyable task: feeding the turtles. I was quick to learn that they all had their own separate personalities – my favourite being three-year-old Turbo. His confident and playful nature set him apart from the other turtles. Until getting up close with the turtles that day, I never realised their striking resemblance to dinosaurs. Everything from their beaks to the intricate patterns on their shells harboured similarities to these prehistoric creatures. This week at TropWATER has not only strengthened my passion for marine science but has also opened my eyes to the diverse roles, responsibilities, and people that make up this incredible field. From feeding loggerhead turtles to watching a dugong glide gracefully through the water, every moment has left a lasting impact. I’m walking away with new knowledge, unforgettable memories, and an even greater determination to protect our oceans.

A $7.5 million partnership between North Queensland Bulk Ports Corporation (NQBP) and James Cook University (JCU) will deliver a five-year program to advance marine science across four ports, led by JCU TropWATER. Building on a decade of nationally recognised collaboration, the partnership will deliver world class monitoring, research, education and training. It will also expand into new areas such as marine habitat restoration research, marine animal studies such as dugongs and turtles, and increasing Traditional Owner engagement. NQBP CEO Brendan Webb said the new partnership solidifies NQBP’s long-term commitment to environmental stewardship and collaboration. “As the only port authority managing three ports within the Great Barrier Reef World Heritage Area, we take our environmental and social responsibilities in these iconic surroundings seriously,” Mr Webb said. “This partnership represents the gold standard for how industry and research institutions can work together to protect and understand the environment. “Together, we’ve delivered world-class monitoring, empowered Traditional Owner engagement, and fostered the next generation of marine scientists. This renewed partnership ensures we build on those achievements into the future.” JCU Deputy Vice Chancellor, Research Professor Jenny Seddon said the partnership continued to demonstrate the real-world impact of JCU’s research. “Our collaboration with NQBP shows how industry and universities can work together and embed scientific expertise into core port operations to deliver real and lasting benefits to the environment, communities and industry,” Professor Seddon said. TropWATER's Professor Michael Rasheed, JCU’s co-director of the program, said at its core the partnership supports world class research and monitoring, including one of the world’s longest continuous running seagrass monitoring program. “These programs have led to breakthrough knowledge on how coastal ecosystems function including developing tools for their effective management and approaches to restoration of seagrass meadows that can be applied throughout tropical Queensland and the Indo-Pacific,” Professor Rasheed said. “The program reaches well beyond the ports themselves with results fed into regional reporting on waterway health and advancing science and management. This is a great example of how research and industry partnerships can benefit society,” he said. TropWATER's Associate Professor Nathan Waltham said the partnership is a model for how industry and research can work together to deliver real-world outcomes. “We’re proud to be training the next generation of marine scientists and delivering the data and solutions needed for resilient, thriving port environments,” Associate Professor Waltham said. “It also provides extraordinary opportunities for our students and researchers to work at the forefront of marine science.”

Dugong and juvenile golden trevally ( Gnathanodon speciosus) © lemga/Getty Images JCU TropWATER researchers have led the most comprehensive look at the world’s dugong populations in over 20 years – revealing where more work is urgently needed. Released this week, the Global Assessment of Dugong Status and Conservation provides a snapshot of what is currently known about this vulnerable species across the waters of more than 40 countries and territories. TropWATER’s Professor Helene Marsh, the lead editor of the report, emphasised the variation in the status and conservation needs of dugongs across their range. “There are apparently stable dugong populations in some parts of Australia and the Arabian Gulf but critically endangered populations in some other regions, so their needs are very different,” Professor Marsh said. “Genetic diversity also varies – even between stable groups – with the higher diversity in Australia associated with greater resilience to environmental changes.” The report found similar variation in local threats to dugong lives and reproduction – although some pressures may be felt worldwide. Habitat loss and degradation were found to be increasing across the entire dugong range, worsened by coastal development and climate change. “The loss of seagrass meadow habitats can lead dugongs to starve, particularly in isolated populations where they have no other meadows to turn to,” Professor Marsh said. As seagrass is the main food source for dugongs, the report calls for urgent seagrass mapping in all regions, particularly the Red Sea, Asia, and Pacific islands. TropWATER researcher Dr Len McKenzie found that over 80% of seagrass that has been mapped in the dugong’s range is in Australia, and that some isolated islands have too little seagrass to support robust dugong populations. “A significant amount of dugong research has been done in Australia, and there is still more work to be done,” Professor Marsh said. “The global dugong research community needs to work together to develop new techniques and refine monitoring methods than can then be used to help conserve dugong populations around the world.” TropWATER is actively collaborating with international researchers, including projects in Mozambique, New Caledonia, and the United Arab Emirates, to foster dugong research efforts worldwide. The Global Assessment of Dugong Status and Conservation Needs was prepared for the Convention on the Conservation of Migratory Species of Wild Animals and features contributions from over 70 international experts, and is available online: https://dugong.cms.int/publication/global-assessment-dugong-status-and-conservation-needs

What is blue carbon? Blue carbon is carbon captured and stored in marine and coastal ecosystems, including mangroves, saltmarshes, seagrass meadows, and coastal wetlands. Similarly to blue carbon, teal carbon is carbon captured by non-tidal freshwater wetlands. Through the process of photosynthesis, plants in these coastal ecosystems capture carbon dioxide from the air or seawater. Carbon is then stored within the plant – in the stems, leaves, roots, or rhizomes. Over time, the carbon captured is deposited in the soil below, through burial of organic matter under sediment, the release of organic compounds from plant roots (known as root exudates) into the surrounding sediment, or through incorporation by animals, such as tidal crabs. These coastal ecosystems often capture and store carbon at much faster rates and more efficiently than terrestrial forests because they rapidly build up sediment and are submerged in water – this restricts oxygen which slows decomposition. Why is blue carbon important? Carbon sequestration – the capture and long-term storage of carbon – is an important way that ecosystems can capture carbon dioxide from the atmosphere and mitigate climate change. If these ecosystems are damaged or destroyed, they release the carbon they have already stored while also losing the ability to capture more. This is occurring across much of our coastlines as sea levels rise, eroding shorelines. Blue carbon programs aim to support the conservation and restoration of these coastal ecosystems to strengthen their capacity to capture carbon and store it in the long term. Blue carbon storage is just one of many vital services these coastal ecosystems provide, along with protecting shorelines from storm surges, providing nursery habitats for fisheries, and improving water quality. Our work with blue carbon ecosystems From understanding carbon storage to restoring coastal habitats, our researchers are working on a range of projects to conserve and restore blue carbon ecosystems. Our work is also setting new methods and standards for blue carbon measurement and restoration and influencing blue carbon policies. Our projects include: Trialling methods to restore seagrass meadows, mangroves, oyster reefs, and Vallisneria  meadows. Identifying areas suitable for wetland restoration along the Great Barrier Reef coastline. Investigating the ways mangroves in Australasia and southeast Asia store carbon depending on the geomorphology of where they grow. Surveying mangrove health and assessing how mangroves are impacted by extreme climate events across the Great Barrier Reef region and the Gulf of Carpentaria. Creating a tool to track the progress of mangrove conservation and restoration internationally.   Related projects: Scoping coastal wetlands and suitable trees for blue carbon restoration Restoring tropical seagrasses and their ecosystem services Oyster and Vallisneria restoration with Wanjuru-Yidinji Traditional Owners Roadmap to large-scale restoration

Murky waters, resident crocodiles, dense seagrass, and elusive species make studying fish in seagrass meadows challenging – testing the limits of available monitoring techniques. A new study by James Cook University TropWATER scientists explores the benefits and limitations of monitoring techniques for fish and prawns, providing a practical roadmap to help researchers choose the right tools for the right conditions in seagrass habitats. The team reviewed 13 common methods, from nets and trawls to underwater cameras, sonar, and cutting-edge environmental DNA (eDNA). Each method has trade-offs. Some risk disturbing seagrass, others falter in turbid water, while eDNA excels at detecting species but cannot yet measure abundance. Darcy Philpott, a PhD student with TropWATER and lead author of the study, said the research provides an important guide for choosing the right monitoring techniques. “Studying fish and prawns in seagrass meadows is challenging, with species behaviour and traits making them hard to find,” she said. “Our message is that no single method gives you the full story. By combining complementary techniques, researchers can capture a more complete picture of biodiversity without disturbing these habitats.” The research was supported by the partnership between North Queensland Bulk Ports Corporation and James Cook University through a scholarship and research funding. JCU TropWATER conducts annual seagrass monitoring as part of this partnership, collecting over 30 years of data in ports. Professor Michael Rasheed, seagrass scientist and program lead, said without reliable monitoring, declines in these habitats could go unnoticed until it’s too late. “We can’t protect what we can’t measure. Better monitoring tools mean better management and stronger conservation of seagrass meadows and the fisheries they support,” he said. “We have a strong commitment to work with industries to ensure the habitats surrounding Ports are well protected and managed in a way that has minimal impact on the local environment. “This NQBP partnership has allowed us to take this monitoring further – we can assess what we do, improving our techniques and sharing this knowledge with other researchers and with port managers.” Future work will focus on refining monitoring approaches to improve biodiversity assessments while reducing environmental impacts. The study is published in Marine Environmental Research : https://doi.org/10.1016/j.marenvres.2025.107395

Wetlands are gaining attention as a potential water quality management tool, but how effective are they in practice across the Great Barrier Reef catchments? As part of TropWATER’s Water Quality Science and Agriculture Hub, a series of practical resources have been developed to show how well-designed wetlands can support farmers with evidence-based solutions to improve water quality across the landscape. Webinar: Scientific projects investigating wetlands and water quality In this recorded webinar, scientists share findings from a global literature review and on-ground wetland monitoring projects that investigated the key factors influencing a wetland’s ability to process and break down nutrients and trap organic matter and sediment particles. The presentations were delivered by Terrain NRM, C2O Consulting, JCU TropWATER, and Alluvium and also covered the research gaps that remain. Insights from these projects are strengthening the evidence base for building and refining wetland models and guiding the future management and design of natural and constructed wetlands. The webinar was facilitated by JCU TropWATER’s Dr Stephen Lewis. The featured projects were funded through the partnership between the Australian Government’s Reef Trust and the Great Barrier Reef Foundation (GBRF). 0 to 6:00 Introduction 6:00 to 23:40 Jane Waterhouse (C2O Consulting and TropWATER): Wetland water quality synthesis 23:40 to 36:30 Alicia Buckle (Terrain NRM): Tully Wetland water quality 36:30 to 50:20 Nathan Waltham (JCU): Sandringham wetland water quality 50:20 to 1:02:35 Tony Weber (Alluvium): Modelling wetland water quality 1:02:35 to 1:03:40 Wrap up Wetlands & Agriculture Story: change, science, solutions The Wetlands & Agriculture Story: change, science, solutions  explores how these landscapes have shifted in the Great Barrier Reef catchment over the past century and what this means for agriculture and water quality today. Natural versus constructed wetlands – what’s the difference? A century of change across Queensland’s coastal wetlands What wetlands look like now in agricultural catchments The science behind their role in improving water quality How wetlands can function as practical management tools The essentials: design, purpose, and ongoing care Explore Wetlands & Agriculture Story: change, science, solutions For broader scientific information on wetlands and all their ecosystem services, see WetlandInfo – the Queensland Government’s repository for all scientific material regarding wetlands. About the Water Quality Science and Agriculture Hub The Water Quality Science and Agriculture Hub is a central space for clear, independent, science-based information on water quality and agriculture, primarily sugarcane. It is a dynamic repository that connects real-world farming challenges with evidence-based solutions – cutting through confusion, misinformation, and politicisation. The Hub is facilitated by JCU TropWATER. The core team includes water quality scientists Dr Stephen Lewis and Dr Zoe Bainbridge, and science communication specialist Molly McShane. The Hub collaborates with water quality experts, industry, and regional groups to create meaningful content. Together, we are connecting science and practice in ways that are useful for staff, growers, NRM groups, regional stakeholders, and governments.

Image credit: European Space Agency. What is a flood plume? A flood plume – also known as a river plume – is a large volume of freshwater discharged from a river into the ocean, caused by heavy rainfall and flooding. Plumes can carry sediment, nutrients, pesticides and other contaminants from the land into coastal and marine waters. How far the flood plume spreads depends on factors such as the volume of water discharged, wind and currents, and how long the flooding lasts.   How do flood plumes affect marine ecosystems? Sediment and nutrients transported by flood plumes can have significant negative impacts on the health of inshore seagrass meadows and coral reefs by: Reducing light  – sediments suspended in water can limit the available light for plants to grow. Smothering  – silt and mud can cover seagrass and coral. Increasing nutrients  – higher nutrient levels can stimulate macroalgal growth, which can eventually outcompete corals and can cause coral disease and increased bioerosion. Coastal and inshore areas are the most likely to be affected by flood plumes as they are located closer to the source of the plume, although larger plumes can carry suspended sediment and nutrients to mid and outer reefs. There is a lot of evidence about the impacts of flood plumes on inshore areas but less it known about impacts further offshore. The severity of these impacts depends on the timing and size of the flood plume, the amount of sediments and nutrients carried by them, the health of the ecosystems prior to exposure to the plume, and whether other disturbances occur at the same time (such as cyclones or high temperatures). Our work monitoring flood plumes Our researchers have been studying how river runoff and flood plumes move within the Great Barrier Reef for over two decades. We also work with landholders and agricultural professionals to provide science-based solutions for improved farm management practices to reduce fertiliser and pesticide losses and manage soil erosion. Our work includes: Sampling flood plumes from major rivers across the Great Barrier Reef catchments. Developing techniques to assess water quality remotely using satellite imagery. Fine-scale monitoring of sediment and nutrient sources on agricultural lands, in collaboration with landholders. Developing models to predict pollutant pathways and identify pollutant ‘hotspots’ for targeted management.   Related projects: https://www.agwaterscience.com/ https://www.tropwater.com/projects/impact-of-water-quality-and-river-plumes-in-the-great-barrier-reef https://www.tropwater.com/projects/large-scale-water-quality-monitoring-using-remote-sensing https://www.tropwater.com/projects/pollutant-sources%2C-transport-and-fate-across-catchment-to-reef-

JCU TropWATER’s Dr Paula Cartwright recently spent eight weeks working with scientists at the Indian Institute of Technology (IIT) Bhubaneswar on advancing remote sensing technologies to track key indicators of water health from space.   Dr Cartwright, who works with port industries to monitor short- and long-term changes in water quality, was awarded this opportunity with leading experts in remote sensing after receiving the Australia India Institute fellowship for women in STEM.   While TropWATER scientists have worked extensively in the fields of remote sensing and water quality – including mapping and monitoring floods and tracking changes in mangrove health – this project uses new satellite technologies to monitor water health at higher resolutions than previously possible. “We set out to improve methods to track and manage water quality, specifically around coastal ports in the Great Barrier Reef region,” she said.   “Using high resolution satellite imagery, validated by on-ground data, we were able to assess water health remotely, in a far more robust and detailed way. This method is cost-effective and is a big step in helping industries manage their environments sustainably.” Dr Cartwright said the fellowship was professionally and personally deeply rewarding.   “Through this fellowship, I built meaningful relationships and laid the groundwork for lasting collaborations,” she said. “I gained insight into regional environmental challenges and approaches, while sharing knowledge from my own research.”   “These exchanges not only enriched my own perspective but also opened the door to collaborative research opportunities.”   This international collaboration will strengthen current remote sensing projects and has inspired ideas for potential future research, such as exploring remote techniques to understand light availability in turbid waters across the coastal Great Barrier Reef.

JCU TropWATER researchers have studied dugong populations for decades, and our marine megafauna team continues to lead cutting edge projects to improve our understanding of dugong ecology. This work is critical to effectively conserve this culturally and ecologically important species. This week, to celebrate World Dugong Day, we’re presenting a snapshot of our work studying dugongs around Australia and globally. All of these projects are designed and undertaken in collaboration with Traditional Owners on their Sea Country.  We’re surveying dugong populations from the air Where: WA: Shark Bay, Ningaloo, Exmouth Gulf; QLD: Torres Strait, Great Barrier Reef, Hervey Bay, Moreton Bay; QLD/NT: Gulf of Carpentaria We use small planes to regularly survey dugong populations across northern Australia, with most regions surveyed every five years. Cameras attached to survey planes capture thousands of images, and our researchers are developing artificial intelligence methods to quickly and accurately analyse these images. Recent surveys showed a decline in dugong numbers across the southern Great Barrier Reef, compared to around 7,000 dugongs living in the waters of the northern Great Barrier Reef. Read more: https://www.tropwater.com/projects/large-scale-monitoring-of-dugong-populations-across-northern-australia- We’re tagging dugongs to track movement and behaviour Where:  WA: Broome, Shark Bay; QLD: Moreton Bay; New Caledonia; Mozambique Our researchers are using GPS-satellite and multi-sensor tags to track the movements, diving behaviour and habitat use of dugongs, detecting behaviours not visible from above the ocean’s surface. Understanding how dugongs use their habitats will inform local and regional management and give insights into potential disturbances to dugongs. Our team has provided specialist technical support for dugong tagging projects in collaboration with African Parks in Mozambique, Yawuru Traditional Owners in Broome, and the Australian National University in Shark Bay. We’re assessing the health of dugongs Where: WA Broome; QLD: Townsville region, Moreton Bay We are developing a non-invasive method to assess dugong body condition using drone-based photogrammetry. Body condition is an indicator of nutritional health, a key element to inform dugong conservation and population management strategies. Drone footage of dugongs is being collected mainly in Cleveland Bay and Moreton Bay (Australia), with plans to expand through collaborations across the dugong’s range. We’re using new genomic tools to assess dugong genetic health and population connectivity Where: Australian dugong range, from Shark Bay to Moreton Bay We are using genomic tools to assess the genetic health and connectivity of dugong populations across northern Australia. This includes whole-genome sequencing and ancient DNA analysis to examine genetic diversity, population structure, historical population changes, and gene flow between regions. In 2025, as part of a major collaborative effort between JCU researchers and Traditional Owners from across northern Australia, the team sequenced 90 dugong samples from key locations including Shark Bay, Exmouth Gulf, Port Hedland, the Kimberley, the Gulf of Carpentaria, Torres Strait, and different locations throughout the Great Barrier Reef. Samples from Mozambique and New Caledonia were also included to provide broader regional context. We’re partnering with and training Indigenous sea Rangers on the use of small drones to monitor marine megafauna species Where: WA: the Kimberley; QLD: Yarrabah, Innisfail, Cardwell, Townsville TropWATER works alongside Traditional Owners to train Rangers in drone-based monitoring of marine megafauna (such as dugongs) and seagrass habitats. We help Rangers become independent in the use drones to detect and monitor the presence of dugongs and other animals and to map seagrass meadows across tidal zones. This data is used to track seasonal changes, identify key feeding areas, and support Ranger-led long-term monitoring. These projects support community-led mapping and data collection to strengthen management of Sea Country using both scientific and cultural knowledge. We’re using small drones to assess the body condition of dugongs Where: QLD: Cleveland Bay, Moreton Bay We're developing a non-invasive method to assess dugong body condition using drone-based photogrammetry. Body condition is an indicator of nutritional health, providing key information for dugong conservation and population management strategies. At this stage, drone footage of dugongs is being collected mainly in Cleveland Bay and Moreton Bay, with plans to expand through collaborations across northern Australia  We’re connecting with Traditional Owners to share dugong knowledge Where:  QLD: Great Barrier Reef Our Dugong Connections project brings together Traditional Owners and scientists to build connections, exchange knowledge, and reshape the way we approach dugong research, monitoring, and management. Together, we’re respectfully exploring opportunities for knowledge sharing, training, dugong surveys and culturally and ecologically sustainable management practices to help dugong populations remain healthy across the Great Barrier Reef. Read more: https://www.tropwater.com/projects/dugong-connections 'Dugong Connection' artwork by Robert Paul.

The new JCU TropWATER coastal health tracker brings together thousands of aerial images from our surveys of northern Australia’s coastlines in one online tool for anyone to use. From monitoring shoreline condition to evaluating storm impacts, this tool will enable researchers, communities, governments, and environmental managers to investigate a range of factors shaping their coastlines. Read on for examples of how we have already used this imagery to address ecological challenges across northern Australia. Identifying hotspots for restoration Where: Cairns to Gladstone Assessing tidal wetland condition and current threats is critical to identify where restoration efforts might be effectively applied. Coastal survey imagery can be used to evaluate damage to or loss of intertidal wetlands and the processes threatening their health for targeted intervention. Our team partnered with Greening Australia to evaluate potential areas for tidal wetland restoration from aerial imagery along the coastline from Cairns to Gladstone. They identified over 17,000 hectares with high potential for coastal restoration. Read more: https://www.tropwater.com/projects/scoping-coastal-wetlands-and-suitable-trees-for-blue-carbon-restoration Assessing the impacts of storms and floods Where:  Cooktown to south of Cairns Aerial surveys are crucial to assessing the impacts of severe storms and floods on shorelines and coastal ecosystems, with imagery collected prior to these events providing important information on baseline conditions. TropWATER researchers assessed the impacts of severe flooding associated with Tropical Cyclone Jasper on the coastline using imagery from aerial surveys one year after the event. This provided insights into potential sites for targeted restoration and early signs of natural recovery. Finding ghost nets and plastic pollution Where: Gulf of Carpentaria Ghost nets (discarded or lost fishing nets) are a significant marine pollution issue and pose a serious threat to marine animals that may become entangled in these nets. Ghost nets can be identified from shoreline imagery to determine hotspots for net accumulation and to assess how the spread of ghost nets may be changing over time. Researchers from CSIRO, the Institute of Marine and Antarctic Studies, and Earthwatch collaborated with TropWATER scientists to identify ghost nets using this approach in the Gulf of Carpentaria – read the full paper here: https://doi.org/10.1016/j.marpolbul.2021.112959 Tracking mangrove recovery after diebacks Where: Gulf of Carpentaria Coastal imagery from repeat surveys over the same stretches of shoreline can provide valuable insights into natural recovery of mangroves and tidal wetlands after dieback events. Our team have assessed the impact of the 2015-2016 mangrove mass dieback in the Gulf of Carpentaria, identifying over 80 square kilometres of mangrove forests were lost. The team are now tracking how mangroves have recovered over the decade since the dieback event. Read more: https://www.tropwater.com/projects/regional-scale-aerial-surveys-of-mangroves-across-northern-australia Explore our coastal imagery datasets here: https://www.tropwater.com/coastal-health-tracker

Representatives of organisations in the Catchment Water Quality Alliance. Credit: Michael Madlo. Scientists at James Cook University TropWATER are expanding their long-standing water quality monitoring and community engagement through a major new initiative – the Catchment Water Quality Alliance. The new Catchment Water Quality Alliance brings together researchers from JCU TropWATER, the University of Queensland’s Reef Catchment Science Partnership and the Queensland Department of the Environment, Tourism, Science and Innovation. The Alliance will improve water quality monitoring, enhance innovative data sharing platforms and engage regional stakeholders to assist communities and organisations to better care for Queensland waterways. TropWATER will support monitoring program across North Queensland while broadening the communication of results through existing local-scale water quality projects and extension networks. JCU TropWATER Director, Professor Damien Burrows, said TropWATER brings over three decades of experience working with growers, graziers and governments to monitor and improve water quality in the Great Barrier Reef. “Being based in North Queensland, close to reef catchments, gives us a unique ability to respond quickly to local weather events to capture critical data that feeds directly into government datasets – building a clearer, more regionally informed picture of water quality issues,” he said. “Our strength is not just in monitoring and research, but how we work with communities. We focus on communicating the science clearly and directly to growers and regional groups, allowing the data to be understood and used where it matters most. “With Alliance staff based in Townsville, we’re well positioned to connect local insights, water quality science and decision-making. This partnership will enhance how data, communication and collaboration can drive water quality solutions.” The water quality monitoring data will be used for a range of purposes including reporting on the health of the waterways, rivers and reef and guiding best practice for improving catchment management initiatives across Queensland. The collaboration will also allow for a deeper exploration of data that has been collected over the past 20 years. The efforts of the Alliance will build on work already underway such as the Great Barrier Reef Catchment Loads Monitoring Program (GBRCLMP) and the South East Queensland (SEQ) Catchments Water Quality Monitoring Program. GBRCLMP involves First Nations, industry and Natural Resource Management (NRM) groups as well as landholders to undergo comprehensive training, equipping them with the skills and knowledge needed to track long-term trends in catchment health, while fostering a deep understanding of local waterways. Queensland Chief Scientist Professor Kerrie Wilson said this collaborative initiative will play a vital role in protecting Queensland’s iconic ecosystems and ensure the resilience of the Great Barrier Reef and SEQ catchments for generations to come. “By harnessing scientific expertise from both government and academia, and using innovative approaches in Reef and SEQ catchment areas, it will help us to stay at the forefront of water quality assessment,” Professor Wilson said. “The Alliance will help to provide the science and real-world data to inform environmental decision-makers.” University of Queensland Head of the School of Environment, Professor Steve Chenoweth said UQ is excited to be joining the Alliance. “It’s a new model for how universities can work more effectively with government,” he said.  “Not only is it an opportunity to focus our world-leading scientific capability on delivering what’s needed for Queensland’s outstanding catchments and reefs, the Alliance also offers unique training opportunities for Queensland’s future environmental scientists who will be better equipped to understand how they can deliver real-world impacts.”

As part of the newly-launched Water Quality Science & Agriculture Hub, Dr Stephen Lewis delves into the history of the Great Barrier Reef, tracing its development over the past 7,000 years and exploring the complexities of establishing a baseline for assessing its health. He examines how scientists use geological and coral records to measure the reef's health over centuries and millennia, shedding light on how the frequency of disturbances like river runoff and coral bleaching has increased in recent times. This story first appeared on the Water Quality Science & Agriculture Hub blog. There are several reasons that motivate me to do my research. Mostly it is to quantify what has changed in our local region over the longer term and to share this knowledge with others. For the Great Barrier Reef, that means exploring one of my favourite topics: long-term environmental and climate records. These records help us build a baseline of the Reef’s natural variability. But how do we establish a starting point to measure its health? The answer is more complex than it seems. Let’s think about climate change Scientists have grappled with measuring changes to environmental health for years. Let’s think about this in terms of climate change research. We know the climate is changing rapidly, and to understand future impacts, scientists look to the distant past. We also know that rapid climate shifts have happened before, some leading to mass extinctions – and some of those ancient events are used to downplay today’s climate crisis. But is it valid to compare climate changes from over 10 million years ago to what’s happening now? Modern humans have only been around for 300,000 years – a blink in Earth’s 4.6-billion-year history. Our ancestors lived through major sea-level changes, including five ice ages and six interglacial periods. But the rate of today’s change is faster than anything they experienced. So where should we draw the baseline? A human lifetime of 80 years? The 300,000 years of modern human history? The 66 million years since mammals took over? The 580 million years of complex life? Or the full 4.6 billion years of Earth’s story? I honestly don’t know the best answer for climate change, but it does give us great context for measuring the baseline health of the Great Barrier Reef. Seven thousand years young: how old is the reef? So let’s get back to the Great Barrier Reef - how far back should we go to assess the Reef’s current health and future prospects against a long-term baseline? When should we start comparing its recovery and disturbance patterns – like shifts in seawater temperatures, sea-level changes, cyclone intensity and frequency, terrestrial runoff and exposure to sediment and nutrient loads, and crown-of-thorns starfish outbreaks? To answer that, we first need to consider the Reef’s history. The Great Barrier Reef has been in existence for the past 800,000 years. The ‘modern Reef’, as we know today, has only been in place for the past 7,000 years. That’s only about 1 percent of that time. Sea level during the last ice age, around 19,000 years ago, was 125 metres lower than today. This means Australia’s coastline was about 50 to 100 km further offshore. The inshore Great Barrier Reef we know today didn’t exist. It was part of a large floodplain. Back then, the Great Barrier Reef was a thin veneer – a much smaller, narrow strip of reefs growing along the outer edge of the continental shelf. With the melting of the ice sheets, sea-level rose from -125 m to reach present levels around 7,500 years ago. This coincides with when most of the coral reefs of the middle and inner shelf began growing about 7,000 years ago. Coral reef accretion – their growth vertically and laterally – peaked 5,000–6,000 years ago before slowing around 4,000 years ago as most reefs reached sea level and sea levels fell by around 1 m. To put it simply, coral reefs grew quickly to use the best space available and then accretion rates have slowed or even ceased at some sites. This natural shift suggests a 4,000-year baseline for assessing reef health, as it reflects the conditions under which today’s Reef ecosystems evolved –making it a more relevant point of comparison than deeper geological history. Great Barrier Reef monitoring dates back 40 years – how can we go beyond that timeline? There are two large scale monitoring programs that use systematic and reproducible methods to gauge the health of the Reef that allow trends in condition to be evaluated. The Long Term Monitoring Program run by the Australian Institute of Marine Science mostly focuses on the mid and outer reefs of the Great Barrier Reef commenced around 1986. The Marine Monitoring Program run by the Great Barrier Reef Marine Park Authority that focuses on seagrass meadow and coral reef health of the inshore Great Barrier Reef started in 2005. Both of these monitoring programs show disturbances are occurring more frequently, leaving less capacity for recovery. But do we only have “the data” to properly benchmark reef condition trends over the past 20 to 40 years? While these datasets are highly valuable, we need to draw on geological records to build a longer baseline to understand a more complete picture of how the Reef has changed over time and what lies ahead. Coral cores, growth rings, and rubble – how we uncover evidence Now I can come back to my favourite topic – foundational records of climate and environmental change. By studying geological and natural records like coral growth rings, coral rubble, and reef cores, we can find evidence that show when and how often disturbances happened over much longer periods – and in some cases we can date this back 7,000 years. This extends our baseline back much further than a few decades. So, let’s consider these disturbances and the methods we can use to investigate how they have changed beyond our monitoring data, to go back hundreds and even thousands of years. Seawater temperatures and coral bleaching Coral bleaching is a stress response where a coral expels its zooxanthellae. It can be triggered by unusually warm or cold seawater temperatures, low salinity or other environmental stressors. Not all bleached corals die. While severely bleached corals can die and some reefs do not fully recover to their former state – many have the ability to recover if conditions improve. Historical records provide evidence that bleaching at individual or a small cluster of reefs has likely always occurred. But mass coral bleaching events – where bleaching of a large proportion of corals occur across multiple coral reefs – appears to be a relatively recent phenomenon. It was first recorded globally in the strong El Niño of 1983/84, and for the first time in the Great Barrier Reef during the strong 1997/98 El Niño. Since then, the Great Barrier Reef has endured six mass coral bleaching events (2002, 2016, 2017, 2020, 2022, 2024) – each linked to abnormally warm seawater temperatures that persist over several weeks. So how do we know that mass bleaching linked to elevated seawater temperatures is a recent phenomenon, especially when monitoring only dates back to the 1980s? How can we measure past seawater temperatures before reliable instrument measurements were available? This is where we look at coral skeletons. Here scientists can use the chemistry of coral skeletons to quantify the seawater temperatures over much longer periods. Massive corals lay down annual growth rings similar to trees and we can use trace elements such as strontium and uranium in these skeletons to reveal past seawater temperatures.   By counting coral growth rings or using dating methods like radiocarbon or uranium-series, and analysing the skeleton’s chemistry, we can reconstruct past seawater temperatures from long before instruments existed. A recent study used this method on a number of coral core records dating back 400 years and showed that seawater temperatures today are much higher than what they have been over that period. Longer records suggest that seawater temperatures are the highest they have been for at least 20,000 years. More research is required to produce coral reef temperature records that extend further back over the past 7,000 years, although it appears the seawater temperatures are changing faster than what reefs of the past have experienced. Records of tropical cyclone frequency and intensity The Great Barrier Reef holds natural records of past cyclones – like coral rubble piled behind beaches or tossed onto reef flats. Even cave formations (speleothems) on the Atherton Tablelands have captured cyclone history through their chemical makeup. Tropical cyclones can break up coral reefs with large waves. Storm surges then push the broken pieces onshore, forming coral rubble ridges like sand dunes, but made instead of coral fragments. Scientists measure their height and date the fragments to learn about past storms. This tells us when the cyclone occurred and how intense the cyclone was – the more intense the higher the ridge. The records point to the presence of ‘super cyclones’ in the period between 4,000 and 6,000 years ago. Indeed, the past 1,000 years is thought to be a ‘lull period’ for large tropical cyclones. Crown of thorns starfish outbreaks The Great Barrier Reef has now endured four recent waves of destructive crown of thorns starfish outbreaks since the 1960s. The outbreaks of crown of thorns greatly reduce coral cover over a reef and the frequency of these recent outbreaks occurs every 12 to 15 years. While the specific cause of these outbreaks is still subject to debate and under investigation, it is thought outbreaks have become more frequent in recent times. Some scientists believe the increase is due to more food (plankton) from increased nutrients, and others that it is due to less natural predators (such as the triton snails). Both hypotheses may be correct. When crown of thorns starfish die they leave behind small spicules (like a skeleton) that become buried in the reef structure. Sediment cores from coral reefs reveal layers that are indicative of historical outbreaks. This evidence shows crown of thorns starfish outbreaks have occurred in the Great Barrier Reef over the past 6,000 years, although the evidence for the frequency of these historical events is lacking. River discharge and terrestrial runoff The growth rings of the massive corals provide other useful measures of climate and environmental variability, including river discharge and terrestrial runoff. When a coral slice is illuminated under a UV light, thin yellow lines of varying intensity glow from the skeleton. The intensity of these individual lines are directly correlated with the volume of river discharge from the adjacent river catchment. Hence, we can use these coral records as a river gauge to quantify river discharge over hundreds of years. This has been done for the Burdekin River where we can extend the river discharge history back to 1648 CE. Data show that the biggest flow events (top 10%) for the Burdekin River have increased over time. From 1650–1850, they were about 10–12 million ML. This rose to 17 million ML from 1850–1950, and 22 million ML from 1950–2012. The increase in the volume of these large flow events means that river plumes carrying terrestrial pollutants are likely to extend further into the Great Barrier Reef lagoon. Further, the frequency of these large discharge events has increased. From 1650–1850, they occurred about once every 14–20 years. That changed to once every 7 years (1850–1950), and once every 6 years (1950–2012). So, floods have become both larger and more frequent. Discharge over the extreme 2010–11 season was likely the biggest freshwater discharge to the Great Barrier Reef in over 500 years. The chemistry of the coral skeleton also reveals changes in sediment loads discharged to the Great Barrier Reef as a result of land use changes in the adjacent river catchments. The corals are ‘seeing and recording’ the influence of increased terrestrial runoff. Findings emerging from the Marine Monitoring Program show that terrestrial runoff including freshwater, sediments and nutrients are impacting the condition of coral reefs and seagrass meadows within the inshore Great Barrier Reef. Furthermore, the findings also show that good water quality is paramount for marine ecosystems to recover quickly from disturbance events. Data from the Long Term Monitoring Program of the mid and outer shelf coral reefs currently show faster recovery of coral cover relative to their inshore counterparts partly because of better water quality conditions. Summary Geological records provide incredible insights into the Great Barrier Reef, clearly showing the Reef is experiencing disturbances at much greater frequency than it has done for at least the past 500 to 1,000 years. It’s unclear if this is unprecedented over the past 4,000 to 7,000 years – that’s what motivates much of my research. With rising sea temperatures, larger floods, stronger cyclones, and threats like ocean acidification, disturbance frequency is likely to increase. The current observations from monitoring programs suggest that the condition of marine ecosystems have been ramping down over the past decade or so. It’s not all bad news though. Evidence is emerging there are some ‘fortunate reefs’. While coral reefs are declining, some reefs sit in cooler, more sheltered waters. Management efforts like crown of thorns starfish control, restoration, and water quality programs aim to ease pressure and give the Reef a better chance to recover. Time will tell whether these interventions are enough but at least we have some hope in trying. Image credits: Eric Matson, AIMS; Ido Fridberg, JCU; Dr Emma Ryan and Emily Lazarus.

How do corals reproduce? Corals reproduce in two main ways: spawning and brooding. Spawning corals release bundles of eggs and sperm into the water, where fertilisation occurs. The resulting embryos develop into larvae that drift for days to weeks before settling onto reef or rubble and forming a hard skeleton as they grow into young coral colonies. Brooding corals fertilise eggs internally within the parent colony. Sperm released by nearby colonies is ingested through the polyp’s mouth, and the parent then releases mature larvae, which typically settle close to their origin. What is coral recruitment? Coral recruitment refers to the process where coral larvae settle onto a surface, survive, and grow for the first 8-12 weeks of their lives. Coral reefs worldwide face increasing threats including heatwaves and mass bleaching, cyclones, flood plumes, and outbreaks of coral-eating Crown-of-Thorns starfish. Under such pressures, successful coral recruitment is more crucial than ever for reef recovery.   How do we measure coral recruitment? Newly settled corals are microscopic, making them nearly impossible to see directly on the reef. Scientists use artificial surfaces – settlement tiles or plates – that mimic the reef that can be removed two to three months after spawning for examination under a microscope in the lab. Counting coral recruits on the tiles provides an estimate of the average density of recruits at a given reef site. How are our scientists studying and boosting coral recruitment? Our researchers are leading a collaborative study with tourism operators, Indigenous Rangers, NGOs, and other community volunteers to track long-term coral recruitment trends in the Cairns and Port Douglas region using settlement tiles. This is helping to fill critical knowledge gaps in how reefs in the region are faring under increasing pressures and will inform managers and decision makers aiming to enhance early stages of reef recovery. The team has also been part of collaborative efforts to harness spawn in laboratory settings and floating nurseries on the reef to generate millions of coral larvae for settlement – this is called coral seeding. Recent work has focused on settling larvae on artificial settlement devices in the lab, protecting young coral recruits from herbivores and other threats during their most vulnerable early weeks before being deployed to reefs in need. Ongoing research is critical to understanding long-term survivorship of coral recruits through various coral seeding techniques – and to determine whether boosting the number of coral recruits results in more adult colonies contributing to reef health and recovery.   Related projects: Cairns-Port Douglas Reef Hub

What is seagrass? Seagrass is a marine plant – and it is the only flowering plant that can live under ocean waters. There are four major groups of seagrasses divided into around 60 to 70 species. Seagrass can sometimes be mistaken for seaweed, which is algae that does not have a true root system and reproduces via spores. Seagrass is found in intertidal (exposed at low tide) and subtidal (constantly submerged) habitats around most continents of the world, and around many reefs and islands. The Great Barrier Reef Marine Park is home to one of the largest seagrass ecosystems worldwide. Why is seagrass important? Seagrass meadows provide a range of valuable and interconnected ecosystem services, including: Food for marine animals and shorebirds  – seagrass is the main food source for dugongs and sea turtles, and shorebirds can forage for food in coastal meadows. Carbon capture and storage  – by efficiently capturing and storing carbon, seagrass meadows help to reduce levels of carbon dioxide in the atmosphere. Nursery habitats  – seagrasses support important fisheries by providing sheltered habitats for young marine animals. Coastal protection  – the roots and rhizomes of seagrass hold sediment in place, reducing erosion, and some seagrass meadows can reduce wave energy. Water filtration  – by filtering out nutrients and trapping fine sediments from the water, seagrasses improve water clarity and are likely to protect corals from disease. The health of seagrass meadows – and the ecosystem services they provide – are threatened by several direct and indirect factors such as heat stress, runoff from land, human activities, and severe storms. Our work with seagrass As one of Australia’s largest tropical seagrass research groups, we lead a range of seagrass projects across northern Australia that include: Mapping – we work with Traditional Owner groups across northern Australia to map where seagrass meadows can be found. Long-term monitoring  – we work with Traditional Owners and industry across the Great Barrier Reef coastline, Torres Strait, and Gulf of Carpentaria to monitor seagrass in the same areas each year. Long-term monitoring allows us to understand how meadows are changing and identify when scientific advice to management is needed. Restoration  – we are trialling methods to restore seagrass in areas where meadows have been damaged or lost, such as Mourilyan Harbour.   Related projects: Torres Strait seagrass mapping, monitoring and research Monitoring seagrass health in the Great Barrier Reef Post-flood monitoring of seagrass in Hervey Bay and Great Sandy Strait Restoring tropical seagrasses and their ecosystem services

What is a nursery habitat? A nursery habitat is an ecosystem that supports juveniles of marine species. They are often coastal ecosystems such as seagrass meadows, mangroves, and saltmarshes that offer three-dimensional structures compared to flat areas of mud or sand. Different species may need different things from their nursery habitats – this includes a range of factors such as protection, food, proximity to other habitat types, and levels of competition or predation. After growing up in a nursery habitat, many adults will migrate to other types of habitats – this is called ontogenetic movement. A habitat is not considered a nursery for a particular species if that species exclusively uses that habitat throughout its life. Why are nursery habitats important? Nursery habitats support juvenile abundance, growth, and survival – this is critical to maintain healthy adult populations. These populations include many species of commercial, recreational, and cultural importance. Nursery habitats are part of interconnected networks of habitats supporting species across all stages of life. As nursery habitats are often found in coastal ecosystems, they can be at high risk of damage or loss due to coastal development and natural disturbances. Identification and monitoring of nursery habitats can inform development planning to conserve these valuable ecosystems. How are we studying nursery habitats? Our researchers are identifying the types of fish present in different coastal habitats – as well as their size and abundance – to understand how different fish and invertebrate populations use nursery habitats across the Great Barrier Reef region. This includes: Surveying inshore habitats between Mourilyan and Magnetic Island with Traditional Owners and Rangers to identify nursery habitats. Monitoring the long-term abundance, size, and diversity of fish species on coral reefs at inshore islands in the Great Barrier Reef Marine Park. Mapping habitats in reef lagoons in the Coral Sea Marine Park to identify the fish species present and which habitats they prefer. Monitoring fish and invertebrates in disturbed and recovered seagrass meadows to compare nursery function.   Related projects: Monitoring fish communities in nursery seascapes

What is eDNA? Environmental DNA (eDNA) is genetic material that organisms have left behind in the environment where they live – in water, soil, or air. Blood, skin, mucus, excrement, and other cells can all contribute to eDNA. Any organism with DNA, from animals and bacteria to plants and fungi, can potentially leave behind traces in eDNA – but some organisms naturally shed more eDNA than others.   How do we measure it? Water, soil, or air samples are collected in the field. In the lab, DNA is isolated from environmental samples and screened for presence of a particular species using species-specific genetic markers. The extracted DNA can also be sequenced to target all organisms contained in the environmental samples; this technique is called eDNA metabarcoding. This technique allows scientists to detect multiple species at once by targeting a shared fragment of a gene. Different approaches to sampling and detection may be necessary to suit the unique characteristics of target species or sampling environments, such as fast-flowing water, estuaries, and the ocean.   How are we using eDNA? eDNA allows scientists to detect organisms without sighting them, which is valuable for many ecological applications. Our researchers are using eDNA for: Early detection of invasive species. Insights into the range of species living in an ecosystem. Engaging with citizen scientists for biodiversity assessments. Detecting endangered species. Monitoring species that may be difficult to observe. Sample collection for eDNA analysis is cost-effective and relatively simple. Citizen scientists can play a key role in collecting samples, allowing for analysis over large areas, and local communities can lead environmental monitoring efforts. From finding endangered species to strengthening biosecurity, eDNA is a powerful tool to address a range of ecological challenges.   Related projects: eDNA technology revolutionises invasive species biosecurity Using eDNA as a surveillance tool for invasive fish Assessing dugong poo using eDNA

James Cook University TropWATER scientists are boosting the recovery of seagrass meadows in the Cocos (Keeling) Islands Marine Park by installing underwater fences that protected depleted seagrass from turtles grazing to give them a chance for recovery. Now, the first of these protected areas are thriving – growing ten times as thick and twice the height after just three months. The Cocos (Keeling) Islands are a remote group of islands over 2,700 km northwest of Perth, surrounded by a marine park covering more than 467,000 square kilometres. Seagrass meadows grow in shallow waters around the islands, supporting a large green sea turtle population and fish that are a vital food source for the local Cocos Malay community. But the loss of 80% of seagrass in the Cocos Lagoon from 2006-2018 signalled that the meadow was close to collapse – driven by coastal development and weather conditions and exacerbated by grazing pressure from turtles. TropWATER’s Professor Michael Rasheed said while turtle grazing is a natural part of seagrass ecosystems, the dramatic loss of seagrass meant turtles were feeding faster than it could regrow. “The seagrass needed a break — it was already depleted and couldn’t bounce back before the turtles grazed it again. Soon it could have lost its ability to regrow,” Professor Rasheed said. “We needed to step in and support the natural recovery process. This is when we started to section off parts of the meadows with these underwater barriers.” Last year, a JCU TropWATER-led project was launched to install barriers around 400 square metre areas of the depleted meadow to stop turtles from grazing there while seagrass regrew. After three months, seagrass inside the barriers had ten times more coverage and the seagrass had grown more than twice the height of those outside the protection zone. Professor Rasheed, who leads the project, said these early results are very promising for the recovery of seagrasses and the marine life they support. “This is an exciting development because it shows clear recovery potential when habitats receive targeted protection,” Professor Rasheed said. “Seagrass restoration using this approach has never been attempted at this scale before, and we’re relieved it seems to be working as these meadows needed help immediately.” Barriers are now in place at West Island and Home Island, providing protected areas for regrowth and acting as a source of seagrass seeds and propagules for recovery beyond the barriers. Early findings from this project highlight how collaborative conservation efforts can support natural recovery processes through targeted protection. The project is funded by the National Environmental Science Program (NESP) Marine and Coastal Hub, in partnership with Cocos (Keeling) Islands community members, Parks Australia, Cocos Marine Care, and Sea Country Solutions.

An extensive flood plume caused by the recent severe weather event in northern Queensland is pushing vast amounts of river discharge to cover about 50,000 km2 of the Great Barrier Reef from Cairns to Mackay – stretching across inshore, mid-shelf, and outer reefs. James Cook University’s TropWATER water quality expert, Jane Waterhouse, says analysis of satellite imagery shows major flooding from more than 10 river basins has merged to form extensive flood plumes, extending more than 700km along the coastline and 100km offshore in some places. “What we are seeing here is very large and prolonged flood plumes spreading across inshore, midshelf and outer reefs, seagrass meadows and other marine ecosystems,” she said. “Outer reefs are rarely exposed to flood plumes due to their distance from river mouths. The water may not be as turbid as inshore areas, but they are still receiving terrestrial runoff.” Flood plumes reduce light to coral reefs and seagrass, slowing their growth. Prolonged low light and sediment buildup can smother seagrass and weaken corals, increasing their vulnerability to bleaching and disease. “People often think flood plumes are just freshwater. But our modern landscape of urban development, agriculture and grazing lands means higher levels of sediment, nutrients and contaminants can runoff during flooding from gullies, farms, and urban landscapes into catchments and out to the Reef,” said Jane Waterhouse. “Elevated nutrients entering the marine environment often lead to higher levels of macroalgae overgrowth on coral reefs, lower coral coverage, and less new coral growth. Sediments delivered by the plume can remain active for months after the flood event and can cause prolonged reductions in water clarity. “Good water quality helps marine ecosystems thrive and bounce back from threats like mass bleaching. But flood plumes can put them under additional pressure, and their impact depends on how long they last, how intense they are, and how resilient the ecosystem is.” Tracking flood plumes across river basins in the Great Barrier Reef TropWATER remote sensing scientist Caroline Petus said satellite images has been a critical tool under the Marine Monitoring Program to track flood plumes from each river basin. “Analysing satellite images gives us a birds-eye view of the situation and helps us guide field teams to the right locations to collect water samples to assess water quality.” Major to moderate flooding was recorded across nearly every river basin from Cairns to Mackay, creating widespread flood plumes, with significant discharges from the Burdekin, Haughton, Ross, Black, Herbert, Murray, Tully, Johnstone, and Russell-Mulgrave rivers. TropWATER’s Stephen Lewis said the Burdekin River, one of the largest contributors to flood plumes on the reef, recorded its biggest peak flood discharge since 2009. “In just 14 days, the Burdekin River discharged 15.6 million ML of water, which is enough to fill Sydney Harbour more than 31 times,” he said. “At its peak, nearly 1.6 million ML per day flowed from the river. This is the highest since 2009 and larger than the 2019 flood event.” Analysis of coral cores shows that the size of large Burdekin River floods has almost doubled compared to floods occurring 150-350 years ago. “These larger floods are carrying more sediments and nutrients in floodwaters due to increased water volumes coupled with land use changes,” Dr Lewis said. “What’s most concerning is that these floods are prolonged with elevated discharge occurring for over a week. This means that the offshore marine areas are exposed to poor water quality for longer periods. "We're now seeing offshore reefs being affected more frequently from flooding, and we don’t yet fully understand the long-term consequences of that exposure, in combination with other disturbances.” Managing agricultural runoff Sugarcane farming is the largest agricultural industry along the Great Barrier Reef coast.  During the wet season, fertilisers and pesticides are more likely to run off paddocks, as this period aligns closely with the preceding crop harvest and fertiliser application period. TropWATER’s Dr Aaron Davis said while many growers adapt their practices around seasonal rainfall conditions to reduce fertiliser and pesticide runoff, extreme floods like this are beyond management control. “This level of flooding is devastating – entire crops in the Ingham region have been significantly impacted,” he said. “Events of this scale don’t happen often, are difficult to plan for, and highlight the challenges of farming in the tropics.” Dr Davis said helping affected farmers get back on their feet is the first step in minimising longer term environmental impacts from such a major event. The floods also provide an opportunity for scientists to assess how well remediation efforts to reduce gully and streambank erosion have held up and how much sediment has been lost from catchments into the Great Barrier Reef. Water quality monitoring is part of the 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. Detailed assessments of impacts on seagrass meadows and coral reefs will be undertaken in the coming months by JCU TropWATER and the Australian Institute of Marine Science. Satellite images taken from the Copernicus website (@Sentinel Hub).

Damaged mangroves one year after the oil spill in Bahía Las Minas. Photo credit: Carl Hansen, STRI. A new study from James Cook University TropWATER researchers has tracked the full 30-year recovery of more than 300 hectares of mangrove forests severely damaged by a 1986 oil spill in Central America. TropWATER’s Professor Norman Duke and Dr Adam Canning combined on-the-ground observations with remote sensing to investigate what helped and hindered recovery over the last three decades – providing one of the most comprehensive long-term records of mangrove regeneration. “Understanding how mangroves recover from major disturbances plays a big role in guiding efforts and response strategies for damaged mangrove forests in Australia, not just for oil spills but also for cyclones and other environmental threats,” said Professor Duke. The 1986 Bahía Las Minas oil spill In 1986, over 8 million litres of crude oil were spilled in the waters of Bahía Las Minas on Panama’s Pacific coast. The oil spread throughout more than 300 hectares of mangrove forests, killing 69 hectares of mature mangrove trees. Over 300 hectares of mangrove forests were saturated in crude oil in Bahía Las Minas in 1986. Photo credit: Charles Getter, STRI. Professor Duke said most research focused on short term recovery, whereas this study was one of the first to investigate long-term recovery of mature mangrove forests – and the findings were encouraging. “Mangroves that were oiled but not killed suffered significant damage in the early years following the spill. But our study found they but had largely recovered within a few decades,” he said. “Where mangroves were wiped out by the spill, recovery was much slower, but these devastated areas have also recovered. It took 15 to 20 years for seedlings to re-establish the forest, and for canopies to close again. “This shows us recovery is possible, but only if environmental pressures remain the same. Recent studies have generally found the frequency of extreme events has increased, threatening to outpace mangrove’s ability to re-establish and recover from damage.” What this means for Australia and globally While this study examined oil-damaged mangrove forests in Central America, the methods and findings are applicable to mangrove ecosystems anywhere, including Australia. The team has conducted several assessments of changing mangrove habitats around Australia to track the influences of changes in rainfall patterns , sea level changes , and more frequent and severe tropical cyclones . “These detailed, long-term studies of damaged mangrove habitats provide critical information on the vulnerabilities of tidal wetland ecosystems and their capacity to recover,” Professor Duke said. “By better understanding how mangroves respond to damaging events, we are developing more appropriate and more effective strategies to minimise future impacts from human pressures and extreme climate events. “These strategies include developing practical and more inclusive ways to evaluate and monitor mangrove health day-to-day and in the long-term. This provides more effective expert advice for managers, practitioners, and local communities around the globe.”   Read the study in the Bulletin of Marine Science   here .