Ms Catalina Musrri1,2, Professor Adriana Vergés2, Dr Georgina Wood3, Professor Catriona Hurd4, Dr Damon Britton4, Dr Ezequiel M. Marzinelli1
1School of Life and Environmental Sciences, The University Of Sydney, Sydney, Australia, 2School of Biological, Earth and Environmental Science, UNSW, Sydney, Australia, 3UWA Oceans Institute & School of Biological Sciences, The University of Western Australia, Perth , Australia, 4Institute for Marine and Antarctic Studies, The University of Tasmania, Hobart, Australia
Ocean warming and marine heatwaves (MHW) are among the main causes of the global decline of seaweed forests and are predicted to increase rapidly over the next century. Phyllospora comosa (‘crayweed’) is a dominant forest-forming seaweed along SE Australia that supports unique communities of animals. Historical poor water quality likely led to the disappearance of crayweed from reefs along Sydney’s metropolitan coastline, and an ongoing restoration program (‘Operation Crayweed’) has successfully re-established crayweed at some sites. However, predicted warming and the increase in the frequency of MHW threaten the persistence of these forests. Reinforcing populations by transplanting reproductive individuals with high thermal tolerance might help conserve this species and the ecosystem functions and services it provides. Here, we aimed to determine whether the warm-edge crayweed population, which has a different genetic structure from other populations, exhibit higher tolerance to warming and MHW. We hypothesised that the warm-edge population would (i) perform better and (ii) show enhanced tolerance mechanisms than central populations under warming and MHW conditions. To test these hypotheses, the warm-edge and three central crayweed populations (chosen based on genetics data) were exposed to a MHW, gradual warming, or left at ambient temperature for 28 days. We compared the performance of individuals from each population via bleaching, relative growth and maximum quantum yield (Fv/Fm), and the potential mechanisms for thermal tolerance, including quantification of membrane fatty acids and heat shock proteins. Results from this experiment provide new insights into population differences in crayweed thermal resistance mechanisms and novel future-proofing pathways to increase the resilience of restored populations to future climate change.
Presentation Slides – Catalina Musrri
Biography:
Catalina is a Marine Biologist from Chile. She has worked on coastal ecology and is now doing a PhD on crayweed future-proofing restoration at the University of Sydney. For her PhD, she is intending to find the best traits for restoring crayweed considering the increasing climate change stressors.
