Warm-origin seedlings, slimmest margins: Posidonia australis thermal thresholds across latitudes by Clement Tremblin

Join us for the FOURTH lunchtime seminar presenting landmark findings on Western Australian marine heatwaves. With marine heatwaves becoming more frequent and intense, predicting these extreme ocean temperatures is critical to protecting our marine ecosystems. This seminar showcases outcomes from a major, UN-endorsed project managed by the Western Australian Marine Science Institution (WAMSI), bringing together 26 cross-disciplinary scientists from Australia's leading research and government bodies to improve how we forecast and respond to extreme marine heatwaves. • Date: Thursday 3 December • Time: 12pm – 12:45pm (30 min presentation, 15 min Q&A) • Location: Auditorium, IOMRC Building, UWA Crawley Campus • Presenter: Clement Tremblin (ECU / Forrest Foundation PhD Candidate) • Format: In-person and online via Teams. Sessions will be recorded. Seminar Title: Warm-origin seedlings, slimmest margins: Posidonia australis thermal thresholds across latitudes Seminar Description: Can seagrass meadows survive a warming ocean? The answer may lie in their most vulnerable life stage: seedlings. While most climate resilience data focuses on adult plants, this seminar presents a multi-level thermal assessment of Posidonia australis seedlings across an 800 km latitudinal gradient in Western Australia. The findings reveal a critical paradox: warm-edge seedlings tolerate the highest temperatures but live dangerously close to their upper limits, experiencing growth failure less than 2°C before mortality. Under projected high-temperature trajectories, these populations face severe risk this century. Discover how these insights are reshaping seed selection strategies to design climate-ready marine restoration. About Clement Clément Tremblin is a Forrest Foundation PhD candidate at Edith Cowan University. He investigates how seagrass flowering responds to temperature along the Western Australian coast to future-proof seed resilience. Building on his Master’s research on seedling thermal tolerance, his award-winning global fieldwork includes discovering new foraminifera species and invasive taxa.