All at Sea Series Lecture by Malcolm McCulloch

Coral Reefs in a Changing World

A public lecture by Professor Malcolm McCulloch, UWA Oceans Institute, ARC Laureate Fellow and Deputy Director of the ARC Centre of Excellence for Coral Reef Studies.

Reef building corals in partnership with their algal symbionts (zooxanthellae) have been spectacularly successful in building the tropical coral reef edifices that harbour over one-third of the oceans biodiversity. The ongoing viability of these tropical reef systems is however in question, with symbiont-bearing shallow-water corals now facing the combined challenges of global warming and ocean acidification from rapidly rising levels of atmospheric CO₂. Nowhere is this more evident than in our iconic, Great Barrier Reef, which in the summers of 2015 and 2016, experienced some of the most devastating coral bleaching events yet recorded.

In this talk, new findings will be presented on some of the key processes responsible for both the success as well as the vulnerability of reef-building corals to climate change. From research undertaken at UWA’s new Watermans facility, together with field experiments conducted on corals living along our coastline, new insights have been obtained on the fundamentals of coral calcification and its response to climate change. Calcification is the process whereby corals efficiently extract dissolved inorganic carbon (DIC) from seawater and convert it into calcium carbonate, the major constituent of their skeletons. We show that this is a ‘finely-tuned’ process, which although relatively resilient to ocean acidification, is highly sensitive to the thermally induced stress, bleaching, and subsequent coral mortality due to loss of symbionts. Thus the increasing prevalence of global-scale coral mass bleaching events due to abrupt pulses of extreme warming associated with human induced global warming, now represents the major threat to coral reefs world-wide.

Professor Malcolm McCulloch is an ARC Laureate Fellow as well as a Deputy Director of the ARC Centre of Excellence for Coral Reef Studies undertaking research on the theme ‘Coral Reef Futures: a new paradigm for quantifying the resilience of marine calcifiers to ocean acidification and global change’. This research is addressing the important question of the vulnerability of corals to the dynamic and highly interactive processes of CO₂ driven ocean warming and declining seawater pH under ‘real-world’ reef conditions.

Professor McCulloch received his PhD from the Californian Institute of Technology (Caltech) and previously held an appointment at the Australian National University. In 2009 he returned to Western Australia, where he grew up, to up an appointment at UWA as a Western Australian Premier’s Fellow. He is an ISI Highly Cited Researcher publishing over 300 scientific papers in leading international journals including 26 in Science and Nature. He is a Fellow the Australian Academy of Science as well as the Royal Society (London).

About this Series: All at Sea - Restoration and Recovery

Our Oceans and coasts provide us with food, energy, livelihoods, cultural and recreational opportunities, yet they are coming under increasing pressure. This UWA Institute of Advanced Studies - Oceans Institute Lecture Series explores the wonders of our seas, the challenges they face and how research at UWA- in a diverse range of fields including marine science, ocean engineering, health., humanities and social sciences- are contributing to sustainability.