Spatial patchiness in change, recruitment, and recovery on coral reefs at Lizard Island following consecutive bleaching events. (January 2022) - Tebbett, Sterling B.
Abstract: The world's coral reef ecosystems are steadily being reconfigured by climate change. Lizard Island, on Australia's Great Barrier Reef, offers an opportunity to examine coral reef reassembly following disturbance, as this location has been impacted by consecutive tropical cyclones and consecutive coral bleaching events. Based on repeatedly monitoring the same 349 photoquadrats around Lizard Island over a 5-year period (2016–2021) we revealed that bleaching in 2016 drove a ∼50% reduction in hard coral cover, and a concomitant increase in algal turf cover. From 2018 to 2021, significant increases (>600%) in coral cover were detected on two semi-exposed reefs and were associated with substantial Acropora recruitment. By contrast, fourteen lagoonal and back reefs exhibited virtually no recovery nor Acropora recruitment. Given that the timeframe between disturbances is set to decrease, our results suggest that some recovery is possible immediately after severe cumulative disturbances, although this recovery may be highly spatially heterogenous. Graphical abstract: Image 1 Highlights: Recovery of coral reefs following cumulative large-scale disturbances is uncertain. High-resolution sampling was used to examine benthic dynamics post disturbance. >600% increases in hard coral cover were detected on semi-exposed reefs. Recovery was heterogenous and many reefs showed little sign of recovery. As disturbance events become more frequent, reefs may be typified by algal turfs.