Abstract: The talk will provide an early account of the severity and extent of coral bleaching on the Great Barrier Reef in 2020, and how it compares with earlier mass bleaching in 1998, 2002, 2016 and 2017. This year’s event is more extensive than before, affecting parts of the northern, central and southern regions. In the north and south, offshore reefs generally escaped bleaching. Coastal reefs were severely bleached along the entire coastline in 2020. In the south, for the first time, two-thirds of reefs in the Swains and Pompeii region were moderately or severely bleached. These spatial patterns are likely to match gradients in heat exposure. In addition, the history of bleaching matters – northern reefs now have residual populations of tougher coral assemblages, compared to more naïve Acropora-dominated assemblages in the offshore south. The cumulative footprint of all 5 events has expanded further south, and many reefs that were proposed earlier as spatial refuges have now bleached severely at least once in the past 5 years.

Biography: Distinguished Professor Terry Hughes is the Director of the Australian Research Council’s Centre of Excellence for Coral Reef Studies, headquartered at James Cook University in Townsville. A recurrent theme in his studies is the application of new scientific knowledge towards improving management of marine environments, especially coral reefs. His publications focus on population dynamics, life histories, marine ecology, biogeography, and the responses of ecosystems to anthropogenic climate change.  In 2016, Terry was recognised by Nature magazine as one of Nature’s “Top Ten People Who Mattered This Year” for his leadership in responding to coral bleaching throughout the tropics in 2015/6, due to global warming. In 2018, Prince Albert II of Monaco presented him with the 2018 Climate Change Award, recognising his contribution to advancing understanding of the influence of rapid climate change on the world’s coral reefs. He received an Honorary PhD from Trinity College, Dublin in 2019, and a Frontiers in Knowledge Award from the BBVA Foundation in 2020.