Brisbane, Australia – August 26, 2025 – In a groundbreaking development for marine conservation, Australian scientists have made significant strides in refining seawater spray technology designed to shield endangered coral reefs from the devastating effects of bleaching caused by rising ocean temperatures. Researchers at Queensland University of Technology (QUT), in collaboration with the National Marine Science Centre at Southern Cross University, have optimized high-pressure spray systems that generate mist plumes capable of reflecting sunlight away from vulnerable reefs. This innovative approach, detailed in a study published in the Journal of Aerosol Science, marks a pivotal moment in the global fight to preserve coral ecosystems, particularly the iconic Great Barrier Reef, which faces existential threats from climate change-induced heatwaves.
The study introduces new insights into the phenomenon of secondary droplet breakup, a process by which seawater droplets fragment into finer particles after being sprayed. This discovery enhances the understanding of droplet formation, movement, and size dynamics, paving the way for the development of more efficient nozzles and spraying systems. Led by Saima Bukhat Khan of QUT, the research combines advanced wind tunnel experiments with sophisticated computer modeling to simulate droplet behavior under real-world conditions. The findings are set to bolster the efforts of the Reef Restoration and Adaptation Programme’s (RRAP) Cooling and Shading team, which is spearheading the development of seawater misting systems to protect high-priority reefs during periods of extreme heat. Beyond coral conservation, the technology holds promise for applications in agriculture, medicine, and industrial processes, underscoring its potential to address a range of global challenges.
Funded through the Australian government’s Reef Trust in partnership with the Great Barrier Reef Foundation, this project represents a beacon of hope for one of the world’s most biodiverse ecosystems. As coral reefs face unprecedented threats from climate change, the refinement of seawater spray technology offers a practical and scalable solution to mitigate bleaching and support the long-term survival of these critical marine habitats.
The Coral Crisis: A Global Challenge
Coral reefs, often referred to as the “rainforests of the sea,” are among the most biodiverse and ecologically significant ecosystems on the planet. They support millions of marine species, provide livelihoods for coastal communities, and act as natural barriers against coastal erosion and storms. The Great Barrier Reef, stretching over 2,300 kilometers along Australia’s northeastern coast, is the world’s largest coral reef system and a UNESCO World Heritage Site. However, rising ocean temperatures driven by climate change have triggered widespread coral bleaching, a phenomenon in which corals expel the symbiotic algae (zooxanthellae) that provide them with energy, leading to widespread coral death if conditions do not improve.
Bleaching events have become more frequent and severe in recent decades, with the Great Barrier Reef experiencing mass bleaching in 1998, 2002, 2016, 2017, 2020, 2022, and 2024. These events are primarily driven by marine heatwaves, which elevate sea surface temperatures beyond the tolerance levels of corals. The loss of coral reefs has far-reaching consequences, threatening marine biodiversity, tourism economies, and the livelihoods of millions of people worldwide. In Australia alone, the Great Barrier Reef generates billions of dollars annually through tourism, fishing, and other industries, making its preservation a national and global priority.
In response to this crisis, scientists have explored a range of innovative solutions, from coral breeding and transplantation to artificial reef structures and genetic adaptation. Among these, seawater spray technology has emerged as a promising tool to provide immediate relief to reefs during heatwaves. By generating mist plumes that reflect sunlight and reduce water temperatures around reefs, this technology aims to create localized cooling effects, offering corals a temporary reprieve from thermal stress. The recent advancements by QUT and Southern Cross University represent a critical step forward in making this technology more effective and scalable.
The Science Behind Seawater Spray Technology
The core of the QUT-led research lies in understanding and optimizing the behavior of seawater droplets when sprayed into the atmosphere. The study, published in the Journal of Aerosol Science, focuses on the phenomenon of secondary droplet breakup, a process in which larger droplets fragment into smaller, finer particles after being ejected from high-pressure spray systems. These finer droplets are critical to the effectiveness of seawater misting, as they can remain suspended in the air longer, creating a reflective mist that blocks sunlight and cools the water below.
Lead author Saima Bukhat Khan, a researcher at QUT, explained the significance of the findings: “Our research provides a deeper understanding of how these fine droplets form, move, and change in size after being sprayed. This knowledge is essential for designing more efficient nozzles and spraying systems that can maximize the cooling and shading effects on coral reefs.” By refining the technology, the team aims to ensure that mist plumes are dense enough to reflect sunlight effectively while covering a sufficiently large area to protect vulnerable reef ecosystems.
The research combined two complementary approaches: wind tunnel experiments and computer modeling. Wind tunnel experiments allowed the team to simulate real-world conditions, such as wind speed and atmospheric turbulence, to study how seawater droplets behave after being sprayed. These experiments provided empirical data on droplet size, velocity, and dispersion patterns, revealing the dynamics of secondary droplet breakup. The computer modeling component, meanwhile, enabled the researchers to simulate these processes at a larger scale, predicting how droplets would interact with environmental factors over coral reefs.
The results of the study have significant implications for the design of seawater misting systems. By optimizing nozzle designs to produce finer droplets, the technology can achieve greater coverage and reflectivity, enhancing its ability to shield reefs from harmful solar radiation. Additionally, the findings allow for more precise control over the size and distribution of droplets, ensuring that mist plumes remain effective under varying wind and weather conditions. This level of precision is critical for deploying the technology during marine heatwaves, when rapid intervention is needed to prevent widespread bleaching.
The Reef Restoration and Adaptation Programme
The research is a key component of the Reef Restoration and Adaptation Programme (RRAP), a collaborative initiative funded by the Australian government’s Reef Trust in partnership with the Great Barrier Reef Foundation. Launched to address the urgent threats facing the Great Barrier Reef, RRAP brings together scientists, engineers, policymakers, and community stakeholders to develop innovative solutions for coral conservation. The programme’s Cooling and Shading team, which includes the QUT and Southern Cross University researchers, is specifically focused on developing technologies to mitigate the impacts of heat stress on reefs.
The seawater spray technology, often referred to as marine cloud brightening, is one of RRAP’s flagship projects. By spraying seawater into the atmosphere, the technology creates reflective mist plumes that reduce the amount of sunlight reaching the ocean surface, thereby lowering water temperatures around reefs. This localized cooling effect can help corals withstand heatwaves, giving them a better chance of retaining their symbiotic algae and avoiding bleaching. The approach is particularly valuable because it can be deployed rapidly during extreme weather events, offering a targeted solution to protect high-priority reefs.
The QUT-led study builds on earlier research by the RRAP Cooling and Shading team, which demonstrated the feasibility of seawater misting through small-scale trials. The new findings refine this approach by providing a deeper understanding of droplet dynamics, enabling the team to scale up the technology for broader application. The improved nozzles and spraying systems developed as a result of this research will be tested in real-world conditions, with the goal of deploying them across vulnerable sections of the Great Barrier Reef during future heatwaves.
Broader Applications and Implications
While the primary focus of the research is coral reef protection, the findings have far-reaching implications for other fields. The study’s insights into droplet behavior and spray system optimization could be applied to agriculture, where misting systems are used for irrigation and crop cooling. In medicine, the technology could inform the development of aerosol-based drug delivery systems, ensuring more precise and effective administration of medications. In industrial processes, such as cooling systems for power plants or manufacturing facilities, the findings could lead to more efficient spray technologies, reducing energy consumption and environmental impact.
The potential for cross-disciplinary applications highlights the significance of the research beyond marine conservation. By advancing the science of aerosol dynamics, the QUT team is contributing to a range of industries that rely on spray technologies. This versatility underscores the value of interdisciplinary collaboration in addressing complex global challenges, from climate change to public health and industrial efficiency.
In the context of coral conservation, the research also has implications for other reef systems around the world. Coral reefs in regions such as the Caribbean, Southeast Asia, and the Pacific face similar threats from bleaching, and the seawater spray technology could be adapted for use in these areas. By sharing their findings with the global scientific community, the Australian researchers are contributing to a collective effort to protect coral ecosystems, which are critical to global biodiversity and coastal economies.
Challenges and Future Directions
Despite the promising advancements, several challenges remain in scaling up seawater spray technology for widespread use. One key challenge is ensuring the technology’s effectiveness across large reef systems like the Great Barrier Reef, which spans thousands of kilometers. Deploying misting systems over such a vast area requires significant logistical coordination, including the use of boats, drones, or other platforms to deliver the sprays. The QUT team is working to address these challenges by designing systems that are both portable and scalable, allowing for rapid deployment during heatwaves.
Another challenge is the environmental impact of the technology itself. While seawater misting is designed to be a low-impact intervention, questions remain about its long-term effects on marine ecosystems. For example, altering sunlight levels could affect other marine organisms, such as phytoplankton, which play a critical role in the ocean’s food chain. The RRAP team is conducting environmental impact assessments to ensure that the technology does not cause unintended harm, balancing the need to protect corals with the broader health of marine ecosystems.
Energy consumption is another consideration. High-pressure spray systems require significant power to operate, and deploying them at scale could have implications for energy use and carbon emissions. The researchers are exploring ways to optimize energy efficiency, such as using renewable energy sources like solar or wind power to drive the systems. These efforts align with broader goals to ensure that climate adaptation technologies are sustainable and aligned with global efforts to reduce greenhouse gas emissions.
Looking ahead, the QUT team plans to conduct field trials to test the optimized spray systems in real-world conditions. These trials will involve deploying the technology over small sections of the Great Barrier Reef during periods of high thermal stress, allowing researchers to measure its effectiveness in reducing water temperatures and preventing bleaching. The results of these trials will inform further refinements to the technology, with the ultimate goal of integrating it into a comprehensive strategy for coral reef conservation.
The Role of Funding and Collaboration
The success of the research is a testament to the power of collaboration and public-private partnerships. The Australian government’s Reef Trust, in partnership with the Great Barrier Reef Foundation, has provided critical funding for the RRAP, enabling researchers to pursue innovative solutions to the coral crisis. This funding has supported not only the QUT-led study but also a range of other projects aimed at coral restoration, genetic adaptation, and community engagement.
The involvement of the National Marine Science Centre at Southern Cross University highlights the importance of interdisciplinary collaboration in tackling complex environmental challenges. By combining expertise in aerosol science, marine biology, and environmental engineering, the research team has been able to achieve breakthroughs that would not have been possible in isolation. The partnership also reflects a broader commitment to involving local and indigenous communities, who have deep knowledge of the reef and its cultural significance.
The Great Barrier Reef Foundation has played a pivotal role in coordinating these efforts, serving as a bridge between scientists, policymakers, and stakeholders. The foundation’s work extends beyond funding, encompassing public outreach and education to raise awareness about the importance of coral conservation. By engaging communities and fostering a sense of shared responsibility, the foundation is helping to build a movement to protect the Great Barrier Reef for future generations.
A Global Model for Coral Conservation
The advancements in seawater spray technology position Australia as a leader in coral conservation, offering a model for other nations grappling with similar challenges. Coral reefs worldwide are under threat, and the solutions developed in Australia could have global applications. The QUT-led research, with its focus on scalable and adaptable technologies, provides a blueprint for protecting reefs in diverse environmental and economic contexts.
The study’s publication in the Journal of Aerosol Science ensures that its findings will reach a global audience of scientists, policymakers, and conservationists. By sharing their methodologies and results, the researchers are contributing to a growing body of knowledge about climate adaptation and coral resilience. This open approach to science is critical in a field where collaboration and knowledge-sharing are essential for addressing the scale of the challenge.
The research also highlights the importance of integrating technological solutions with broader climate action. While seawater spray technology can provide temporary relief for corals, it is not a substitute for reducing greenhouse gas emissions, which are the root cause of rising ocean temperatures. The Australian government’s commitment to climate action, including its support for renewable energy and emissions reduction targets, complements the efforts of the RRAP and ensures a holistic approach to environmental protection.
A Beacon of Hope for the Great Barrier Reef
As the world grapples with the impacts of climate change, the QUT-led research offers a beacon of hope for the Great Barrier Reef and coral ecosystems worldwide. By refining seawater spray technology, the researchers have developed a practical tool to protect reefs from the immediate threat of bleaching, buying time for longer-term solutions such as coral restoration and climate mitigation. The study’s insights into droplet dynamics and spray system optimization represent a significant leap forward, demonstrating the power of science and innovation to address pressing environmental challenges.
The work of the RRAP Cooling and Shading team, supported by the Australian government and the Great Barrier Reef Foundation, underscores the importance of collective action in preserving natural wonders like the Great Barrier Reef. As the technology moves closer to large-scale deployment, it has the potential to transform the way we protect coral reefs, ensuring their survival for future generations.
For now, the focus remains on testing and refining the technology, with field trials set to provide critical data on its effectiveness. As Saima Bukhat Khan and her team continue their work, they are driven by a shared commitment to safeguarding one of the world’s most precious ecosystems. In a time of uncertainty for coral reefs, their research offers a powerful reminder that innovation, collaboration, and determination can pave the way for a more resilient and sustainable future.
