One Tree Island Research Station

A dynamic week of reef research at OTIRS, bringing together marine ecologists, laser imaging specialists, palaeontologists and a coral fluorescence expert in an international collaboration

Led by Professor Maria Byrne from the University of Sydney (USyd), the team included her PhD students Matthew Clements and Ronan Hill, whose research focuses on crown-of-thorns starfish (COTS) ecology and age structure. Visiting from The Chinese University of Hong Kong (CUHK), Professor Michael Pittman, co-pioneer of Laser-Stimulated Fluorescence (LSF) and Dr Natalia Jagielska, who worked to adapt laser systems, originally developed to visualise soft tissues in fossils, for underwater reef applications.

Funded by the USyd–CUHK Ignition Grant, the project is developing a handheld underwater LSF instrument to non-invasively resolve COTS growth bands as well as capturing fluorescence signatures of coral health. Dr Anya Salih, international leader in coral fluorescence and founder of Fluoresci Research, has been contributing her expertise across both the LSF project and field-based coral health surveys. Working with Matthew Clements, they also documented post-bleaching coral recovery and characterised fluorescence signatures linked to stress resilience.

The team was also joined by Professor Danielle Celermajer from USyd Environment Institute as part of the ‘Corals as Kin’ collaboration, conceived by Dr Anya Salih and now being developed in partnership with Professor Maria Byrne and colleagues across multiple disciplines at USyd. This initiative brings together coral fluorescence science and environmental humanities to explore new ways of understanding coral stress, bleaching and recovery, not only as biological processes, but as signals that reshape how we think about our relationship with reef ecosystems in a warming world.



University of Sydney Faculty of Science, University of Sydney The Chinese University of Hong Kong 香港中文大學 - CUHK

Spotlight on some recent research 🌊🪸🔍 The paper, a rapid communication on the effects of Cyclone Alfred on One Tree Reef, shows for the first time that Spurs and Grooves on forereefs can act as channels to bring sediment onto reef flats. While grooves (the channels of spur and groove systems) have long been suspected to play a role in sediment dynamics, the prevailing view has been that it is “impossible” for rubble to move upslope through them to the reef flat. These findings carry implications for sediment budgets, interpretations of past reef-building processes and forecasts of reef and shingle island evolution under climate change.

Vila-Concejo A, Perris LA, Silva AP da, Whitton K, Meoded-Stern L, Steilberg-Liu W-Y, Holmes R, Breuer H, Byrne M, Fellowes TE, Salles T, Morris BD and Bruce E (2025) Grooves in forereefs act as transport channels to deliver coral rubble during tropical cyclones. Cambridge Prisms: Coastal Futures 3, e29. https://lnkd.in/g5N2QM4e.

Faculty of Science, University of SydneyUniversity of Sydney Marine Studies InstituteUniversity of Sydney

Gigi Beretta and Dave Booth have been coming to One Tree Island for the past 33+ years surveying multiple sites throughout the lagoon and outer reef of One Tree Island. The two were able to bring their two sons for the first time to the station and were so happy to share a place that has been such a big part of their working lives with them. Below is a quote from Gigilia about her time here and the devastating changes they have seen on the reef highlighting how important long-term surveys like their work are to help document and understand the effects of climate change and increased storm/cyclone occurrence on the reef.

"It was amazing finally getting the kids to our special places that dave and I have been privileged to have worked at off and on over the past 33+ years. It was truly joyous to have them there with us. However, the joy of sharing such an amazing place with the kids was deeply overshadowed by the utter devastation our sites have endured over the decade. One Tree has been affected by a number of beaching events (2024 was particularly bad and the last time we visited the site) and last year's Cyclone Alfred appears to have dropped some areas to new low.
The inner lagoon sites have seen the loss of large prominent colonies representing a number of coral Families which has altered structure and habitat and it appears that fish recruitment has been impacted on some of our sites. Most striking was the condition of an amazing outer lagoon site, The Notch, which was utterly drab compared to its past vibrant colours and structure. Below I have included some shots (the 1st 2 photos) that Heinrich and Ruby (One Tree Island Station managers) took of us surveying the site back in 2021 (during a smaller bleaching event) and a few overview photos we took this past Australia Day 2026."

PhD student Annabel Klinke and research assistant Helen von Drenkmann spent two months living and working on OTIRS. Annabel's project explored the impact of decreasing coral reef complexity on damselfish cognition.

To test this the pair were in the water almost every day for the 8 weeks measuring cognitive flexibility and inhibitory control in humbug damselfish using a reversal learning task and a detour tasks, respectively.

Annabel said about her time on OTIRS
"I couldn’t have imagined a better place for my two-month field trip than One Tree Island. I already knew the lagoon would be the perfect spot for my research on humbug damselfish - there are plenty as soon as you enter the water - but what truly made those two months fly by was how welcoming Ruby, Heinrich, and their son Lukas were. Ruby and Heinrich were always available to help with any questions or issues that came up, as they inevitably do during fieldwork. Beyond that, they made us feel right at home - organizing little BBQs, preparing “hot tubs” (big plastic aquaria filled with warm seawater) for us to warm up after hours in the water, and showing us the wonderful island and reef they call home. And the cherry on top: Lukas is one of the sweetest boys I’ve ever met, and I can’t wait to see what his future holds! He was a constant reminder of why I do what I do: contributing to our understanding of how we are affecting the Earth and how we can each do our part to turn the tide." - Annabel K

Thank you for your wonderful feedback. We look forward to learning more about your results and hopefully welcoming you back to continue your research here at OTIRS.

It's been a busy two weeks here at OTIRS with a full house! A team of researchers from the University of Sydney lead by Prof. Ana Vila-Concejo and Dr. Ana Paula da Silva have been running a coastal monitoring training workshop, with international delegates joining from the Philippines and Indonesia. The team demonstrate data collection techniques in bathymetry, hydrodynamics, coral health surveying and benthic mapping. This workshop is part of the Marine Resorces Initiative funded by Geoscience Australia (GA) and the Department of Foreign Affairs and Trade (DFAT). A highly valuable opportunity for collaborating and sharing research ideas and techniques.

University of Sydney Marine Studies Institute Faculty of Science, University of Sydney

https://youtu.be/i6aMj01skdQ

A recording from the 50 year anniversary celebrations for the station held at the University of Sydney 🏝️🎉🙌 the night was a huge success and many wonderful stories, history, research findings were shared.

One Tree Island Research Station - celebrating 50 years of ground breaking research. Celebrating half a century of transformative marine research, conservation efforts and education from the University of Sydney’s One Tree Island Research Sta...

What secrets does the Great Barrier Reef hold? 🤫

Join us to celebrate 50 years of discovery at One Tree Island Research Station! Hear from our leading marine scientists about their deep-sea adventures and discoveries 🔎

Q&A and refreshments to follow 🍿

Don't miss this special event, register for free: https://go.sydney.edu.au/sc5Bcq

Raising a baby on a remote island 'the best thing we ever did' Hours from the mainland and in the middle of the ocean, Ruby Holmes and Heinrich Breuer are raising their son on the Great Barrier Reef.

Last year was the worst bleaching and then subsequent mortality Heinrich and I (OTIRS Station Managers) have seen out here in the 6 years we have been managing the station and it has been heart breaking to see it happen first hand. We are hoping for a cooler summer this year and conditions that allow the corals to recover rather than bleaching again.

Professor Maria Byrne, Alexander Waller et al. just recently published a paper which clearly outlines what we are seeing out here.

Maria and her team tracked the health of 462 coral colonies in the One Tree lagoon over a period of 161 days. Their findings revealed that 66% of the colonies were bleached by February 2024 and 80% by April. By July, 44% of the bleached colonies had died, with some coral genera experiencing a staggering 95% mortality rate.

Professor Ana Vila Concejo, a co-author of the study outlines why these studies are so vital - "This research is a wake-up call for policymakers and conservationists. The resilience of coral reefs is being tested like never before, and we must prioritise strategies that enhance their ability to withstand climate change. Our findings underscore the need for immediate and effective management interventions to safeguard these ecosystems."

Read more below -

https://www.sydney.edu.au/news-opinion/news/2025/01/21/coral-bleaching-2024-great-barrier-reef-one-tree-island.html

University of Sydney Marine Studies Institute Faculty of Science, University of Sydney University of Sydney Marine Studies Institute University of Sydney

Cycle of coral bleaching on the Great Barrier Reef now at 'catastrophic' levels Marine scientists at the University of Sydney have published the first peer-reviewed study of the 2024 mass bleaching on the southern Great Barrier Reef.